diff --git a/packages/app/src/components/dialog-select-directory.test.ts b/packages/app/src/components/dialog-select-directory.test.ts
new file mode 100644
index 000000000000..ddb42caa6dfe
--- /dev/null
+++ b/packages/app/src/components/dialog-select-directory.test.ts
@@ -0,0 +1,61 @@
+import { describe, expect, test } from "bun:test"
+import {
+  getParentPath,
+  joinPath,
+  getPathDisplay,
+  getPathDisplaySeparator,
+  getPathRoot,
+  getPathScope,
+  getPathSearchText,
+  trimPrettyPath,
+} from "@opencode-ai/util/path"
+
+describe("dialog select directory display", () => {
+  test("keeps posix paths looking posix", () => {
+    expect(getPathDisplay("/Users/dev/repo", "", "/Users/dev")).toBe("~/repo")
+    expect(getPathDisplaySeparator("~/repo", "/Users/dev")).toBe("/")
+  })
+
+  test("renders windows home paths with native separators", () => {
+    expect(getPathDisplay("C:/Users/dev/repo", "", "C:\\Users\\dev")).toBe("~\\repo")
+    expect(getPathDisplaySeparator("~\\repo", "C:\\Users\\dev")).toBe("\\")
+  })
+
+  test("renders absolute windows paths with backslashes", () => {
+    expect(getPathDisplay("C:/Users/dev/repo", "C:\\", "C:\\Users\\dev")).toBe("C:\\Users\\dev\\repo")
+    expect(getPathDisplay("//server/share/repo", "\\\\server\\", "C:\\Users\\dev")).toBe(
+      "\\\\server\\share\\repo",
+    )
+  })
+
+  test("preserves UNC share roots for navigation helpers", () => {
+    expect(getPathRoot("\\\\server\\share\\repo")).toBe("//server/share")
+    expect(getPathRoot("\\\\server\\share")).toBe("//server/share")
+    expect(getParentPath("//server/share/repo")).toBe("//server/share")
+    expect(getParentPath("\\\\server\\share")).toBe("//server/share")
+  })
+
+  test("keeps UNC scoped search rooted at the share", () => {
+    expect(getPathScope("\\\\server\\share", "C:/Users/dev", "C:/Users/dev")).toEqual({
+      directory: "\\\\server\\share",
+      path: "",
+    })
+    expect(getPathScope("\\\\server\\share\\repo", "C:/Users/dev", "C:/Users/dev")).toEqual({
+      directory: "\\\\server\\share",
+      path: "repo",
+    })
+  })
+
+  test("keeps pretty paths native while joining search results", () => {
+    expect(trimPrettyPath("C:/Users/dev/repo/")).toBe("C:\\Users\\dev\\repo")
+    expect(joinPath("C:\\Users\\dev", "repo/src")).toBe("C:\\Users\\dev\\repo\\src")
+    expect(joinPath("\\\\server\\share", "repo")).toBe("\\\\server\\share\\repo")
+  })
+
+  test("indexes UNC paths in slash and native forms", () => {
+    const search = getPathSearchText("//server/share/repo", "C:\\Users\\dev")
+    expect(search).toContain("//server/share/repo")
+    expect(search).toContain("\\\\server\\share\\repo")
+    expect(search).toContain("repo")
+  })
+})
diff --git a/packages/app/src/components/dialog-select-directory.tsx b/packages/app/src/components/dialog-select-directory.tsx
index 91e23f8ffa5f..552cd08e31ce 100644
--- a/packages/app/src/components/dialog-select-directory.tsx
+++ b/packages/app/src/components/dialog-select-directory.tsx
@@ -3,11 +3,24 @@ import { Dialog } from "@opencode-ai/ui/dialog"
 import { FileIcon } from "@opencode-ai/ui/file-icon"
 import { List } from "@opencode-ai/ui/list"
 import type { ListRef } from "@opencode-ai/ui/list"
-import { getDirectory, getFilename } from "@opencode-ai/util/path"
+import {
+  getDirectory,
+  getFilename,
+  joinPath,
+  normalizeInputPath,
+  getParentPath,
+  getPathDisplay,
+  getPathDisplaySeparator,
+  getPathRoot,
+  getPathScope,
+  getPathSearchText,
+  trimPrettyPath,
+} from "@opencode-ai/util/path"
 import fuzzysort from "fuzzysort"
 import { createMemo, createResource, createSignal } from "solid-js"
 import { useGlobalSDK } from "@/context/global-sdk"
 import { useGlobalSync } from "@/context/global-sync"
+import { workspacePathKey } from "@/context/file/path"
 import { useLayout } from "@/context/layout"
 import { useLanguage } from "@/context/language"
 
@@ -28,101 +41,27 @@ function cleanInput(value: string) {
   return first.replace(/[\u0000-\u001F\u007F]/g, "").trim()
 }
 
-function normalizePath(input: string) {
-  const v = input.replaceAll("\\", "/")
-  if (v.startsWith("//") && !v.startsWith("///")) return "//" + v.slice(2).replace(/\/+/g, "/")
-  return v.replace(/\/+/g, "/")
-}
-
-function normalizeDriveRoot(input: string) {
-  const v = normalizePath(input)
-  if (/^[A-Za-z]:$/.test(v)) return v + "/"
-  return v
-}
-
-function trimTrailing(input: string) {
-  const v = normalizeDriveRoot(input)
-  if (v === "/") return v
-  if (v === "//") return v
-  if (/^[A-Za-z]:\/$/.test(v)) return v
-  return v.replace(/\/+$/, "")
-}
-
-function joinPath(base: string | undefined, rel: string) {
-  const b = trimTrailing(base ?? "")
-  const r = trimTrailing(rel).replace(/^\/+/, "")
-  if (!b) return r
-  if (!r) return b
-  if (b.endsWith("/")) return b + r
-  return b + "/" + r
-}
-
-function rootOf(input: string) {
-  const v = normalizeDriveRoot(input)
-  if (v.startsWith("//")) return "//"
-  if (v.startsWith("/")) return "/"
-  if (/^[A-Za-z]:\//.test(v)) return v.slice(0, 3)
-  return ""
-}
-
-function parentOf(input: string) {
-  const v = trimTrailing(input)
-  if (v === "/") return v
-  if (v === "//") return v
-  if (/^[A-Za-z]:\/$/.test(v)) return v
-
-  const i = v.lastIndexOf("/")
-  if (i <= 0) return "/"
-  if (i === 2 && /^[A-Za-z]:/.test(v)) return v.slice(0, 3)
-  return v.slice(0, i)
-}
-
-function modeOf(input: string) {
-  const raw = normalizeDriveRoot(input.trim())
-  if (!raw) return "relative" as const
-  if (raw.startsWith("~")) return "tilde" as const
-  if (rootOf(raw)) return "absolute" as const
-  return "relative" as const
-}
-
-function tildeOf(absolute: string, home: string) {
-  const full = trimTrailing(absolute)
-  if (!home) return ""
-
-  const hn = trimTrailing(home)
-  const lc = full.toLowerCase()
-  const hc = hn.toLowerCase()
-  if (lc === hc) return "~"
-  if (lc.startsWith(hc + "/")) return "~" + full.slice(hn.length)
-  return ""
-}
-
-function displayPath(path: string, input: string, home: string) {
-  const full = trimTrailing(path)
-  if (modeOf(input) === "absolute") return full
-  return tildeOf(full, home) || full
-}
-
 function toRow(absolute: string, home: string, group: Row["group"]): Row {
-  const full = trimTrailing(absolute)
-  const tilde = tildeOf(full, home)
-  const withSlash = (value: string) => {
-    if (!value) return ""
-    if (value.endsWith("/")) return value
-    return value + "/"
-  }
-
-  const search = Array.from(
-    new Set([full, withSlash(full), tilde, withSlash(tilde), getFilename(full)].filter(Boolean)),
-  ).join("\n")
-  return { absolute: full, search, group }
+  const full = trimPrettyPath(absolute)
+  return { absolute: full, search: getPathSearchText(full, home), group }
 }
 
 function uniqueRows(rows: Row[]) {
   const seen = new Set<string>()
   return rows.filter((row) => {
-    if (seen.has(row.absolute)) return false
-    seen.add(row.absolute)
+    const key = workspacePathKey(row.absolute)
+    if (seen.has(key)) return false
+    seen.add(key)
+    return true
+  })
+}
+
+function unique(paths: string[]) {
+  const seen = new Set<string>()
+  return paths.filter((path) => {
+    const key = workspacePathKey(path)
+    if (seen.has(key)) return false
+    seen.add(key)
     return true
   })
 }
@@ -135,29 +74,14 @@ function useDirectorySearch(args: {
   const cache = new Map<string, Promise<Array<{ name: string; absolute: string }>>>()
   let current = 0
 
-  const scoped = (value: string) => {
-    const base = args.start()
-    if (!base) return
-
-    const raw = normalizeDriveRoot(value)
-    if (!raw) return { directory: trimTrailing(base), path: "" }
-
-    const h = args.home()
-    if (raw === "~") return { directory: trimTrailing(h || base), path: "" }
-    if (raw.startsWith("~/")) return { directory: trimTrailing(h || base), path: raw.slice(2) }
-
-    const root = rootOf(raw)
-    if (root) return { directory: trimTrailing(root), path: raw.slice(root.length) }
-    return { directory: trimTrailing(base), path: raw }
-  }
-
   const dirs = async (dir: string) => {
-    const key = trimTrailing(dir)
+    const path = trimPrettyPath(dir)
+    const key = workspacePathKey(path)
     const existing = cache.get(key)
     if (existing) return existing
 
     const request = args.sdk.client.file
-      .list({ directory: key, path: "" })
+      .list({ directory: path, path })
       .then((x) => x.data ?? [])
       .catch(() => [])
       .then((nodes) =>
@@ -165,7 +89,7 @@ function useDirectorySearch(args: {
           .filter((n) => n.type === "directory")
           .map((n) => ({
             name: n.name,
-            absolute: trimTrailing(normalizeDriveRoot(n.absolute)),
+            absolute: trimPrettyPath(n.absolute),
           })),
       )
 
@@ -184,12 +108,12 @@ function useDirectorySearch(args: {
     const active = () => token === current
 
     const value = cleanInput(filter)
-    const scopedInput = scoped(value)
+    const scopedInput = getPathScope(value, args.start(), args.home())
     if (!scopedInput) return [] as string[]
 
-    const raw = normalizeDriveRoot(value)
-    const isPath = raw.startsWith("~") || !!rootOf(raw) || raw.includes("/")
-    const query = normalizeDriveRoot(scopedInput.path)
+    const raw = normalizeInputPath(value)
+    const isPath = raw.startsWith("~") || !!getPathRoot(raw) || /[\\/]/.test(value)
+    const query = normalizeInputPath(scopedInput.path)
 
     const find = () =>
       args.sdk.client.find
@@ -213,23 +137,23 @@ function useDirectorySearch(args: {
     for (const part of head) {
       if (!active()) return []
       if (part === "..") {
-        paths = paths.map(parentOf)
+        paths = paths.map(getParentPath)
         continue
       }
 
       const next = (await Promise.all(paths.map((p) => match(p, part, branch)))).flat()
       if (!active()) return []
-      paths = Array.from(new Set(next)).slice(0, cap)
+      paths = unique(next).slice(0, cap)
       if (paths.length === 0) return [] as string[]
     }
 
     const out = (await Promise.all(paths.map((p) => match(p, tail, 50)))).flat()
     if (!active()) return []
-    const deduped = Array.from(new Set(out))
-    const base = raw.startsWith("~") ? trimTrailing(scopedInput.directory) : ""
+    const deduped = unique(out)
+    const base = raw.startsWith("~") ? scopedInput.directory : ""
     const expand = !raw.endsWith("/")
     if (!expand || !tail) {
-      const items = base ? Array.from(new Set([base, ...deduped])) : deduped
+      const items = base ? unique([base, ...deduped]) : deduped
       return items.slice(0, 50)
     }
 
@@ -240,8 +164,8 @@ function useDirectorySearch(args: {
 
     const children = await match(target, "", 30)
     if (!active()) return []
-    const items = Array.from(new Set([...deduped, ...children]))
-    return (base ? Array.from(new Set([base, ...items])) : items).slice(0, 50)
+    const items = unique([...deduped, ...children])
+    return (base ? unique([base, ...items]) : items).slice(0, 50)
   }
 }
 
@@ -348,8 +272,9 @@ export function DialogSelectDirectory(props: DialogSelectDirectoryProps) {
           e.preventDefault()
           e.stopPropagation()
 
-          const value = displayPath(item.absolute, filter(), home())
-          list?.setFilter(value.endsWith("/") ? value : value + "/")
+          const value = getPathDisplay(item.absolute, filter(), home())
+          const sep = getPathDisplaySeparator(value, home())
+          list?.setFilter(/[\\/]$/.test(value) ? value : value + sep)
         }}
         onSelect={(path) => {
           if (!path) return
@@ -357,7 +282,9 @@ export function DialogSelectDirectory(props: DialogSelectDirectoryProps) {
         }}
       >
         {(item) => {
-          const path = displayPath(item.absolute, filter(), home())
+          const path = getPathDisplay(item.absolute, filter(), home())
+          const dir = getDirectory(path)
+          const sep = getPathDisplaySeparator(path, home())
           if (path === "~") {
             return (
               <div class="w-full flex items-center justify-between rounded-md">
@@ -365,7 +292,7 @@ export function DialogSelectDirectory(props: DialogSelectDirectoryProps) {
                   <FileIcon node={{ path: item.absolute, type: "directory" }} class="shrink-0 size-4" />
                   <div class="flex items-center text-14-regular min-w-0">
                     <span class="text-text-strong whitespace-nowrap">~</span>
-                    <span class="text-text-weak whitespace-nowrap">/</span>
+                    <span class="text-text-weak whitespace-nowrap">{sep}</span>
                   </div>
                 </div>
               </div>
@@ -377,10 +304,10 @@ export function DialogSelectDirectory(props: DialogSelectDirectoryProps) {
                 <FileIcon node={{ path: item.absolute, type: "directory" }} class="shrink-0 size-4" />
                 <div class="flex items-center text-14-regular min-w-0">
                   <span class="text-text-weak whitespace-nowrap overflow-hidden overflow-ellipsis truncate min-w-0">
-                    {getDirectory(path)}
+                    {dir}
                   </span>
                   <span class="text-text-strong whitespace-nowrap">{getFilename(path)}</span>
-                  <span class="text-text-weak whitespace-nowrap">/</span>
+                  <span class="text-text-weak whitespace-nowrap">{sep}</span>
                 </div>
               </div>
             </div>
diff --git a/packages/app/src/components/dialog-select-file.tsx b/packages/app/src/components/dialog-select-file.tsx
index e21be77fb94d..93a4ee492bac 100644
--- a/packages/app/src/components/dialog-select-file.tsx
+++ b/packages/app/src/components/dialog-select-file.tsx
@@ -14,6 +14,7 @@ import { useGlobalSync } from "@/context/global-sync"
 import { useLayout } from "@/context/layout"
 import { useFile } from "@/context/file"
 import { useLanguage } from "@/context/language"
+import { findProjectByDirectory, workspaceEqual } from "@/pages/layout/helpers"
 import { useSessionLayout } from "@/pages/session/session-layout"
 import { createSessionTabs } from "@/pages/session/helpers"
 import { decode64 } from "@/utils/base64"
@@ -69,10 +70,10 @@ const createCommandEntry = (option: CommandOption, category: string): Entry => (
   option,
 })
 
-const createFileEntry = (path: string, category: string): Entry => ({
+const createFileEntry = (path: string, title: string, category: string): Entry => ({
   id: "file:" + path,
   type: "file",
-  title: path,
+  title,
   category,
   path,
 })
@@ -137,7 +138,7 @@ function createFileEntries(props: {
   const tabState = createSessionTabs({
     tabs: props.tabs,
     pathFromTab: props.file.pathFromTab,
-    normalizeTab: (tab) => (tab.startsWith("file://") ? props.file.tab(tab) : tab),
+    normalizeTab: props.file.normalizeTab,
   })
   const recent = createMemo(() => {
     const all = tabState.openedTabs()
@@ -152,7 +153,7 @@ function createFileEntries(props: {
       if (!path) continue
       if (seen.has(path)) continue
       seen.add(path)
-      items.push(createFileEntry(path, category))
+      items.push(createFileEntry(path, props.file.display(path), category))
     }
 
     return items.slice(0, ENTRY_LIMIT)
@@ -165,7 +166,7 @@ function createFileEntries(props: {
       .filter((node) => node.type === "file")
       .map((node) => node.path)
       .sort((a, b) => a.localeCompare(b))
-    return paths.slice(0, ENTRY_LIMIT).map((path) => createFileEntry(path, category))
+    return paths.slice(0, ENTRY_LIMIT).map((path) => createFileEntry(path, props.file.display(path), category))
   })
 
   return { recent, root }
@@ -280,7 +281,7 @@ export function DialogSelectFile(props: { mode?: DialogSelectFileMode; onOpenFil
   const project = createMemo(() => {
     const directory = projectDirectory()
     if (!directory) return
-    return layout.projects.list().find((p) => p.worktree === directory || p.sandboxes?.includes(directory))
+    return findProjectByDirectory(layout.projects.list(), directory)
   })
   const workspaces = createMemo(() => {
     const directory = projectDirectory()
@@ -288,7 +289,7 @@ export function DialogSelectFile(props: { mode?: DialogSelectFileMode; onOpenFil
     if (!current) return directory ? [directory] : []
 
     const dirs = [current.worktree, ...(current.sandboxes ?? [])]
-    if (directory && !dirs.includes(directory)) return [...dirs, directory]
+    if (directory && !dirs.some((dir) => workspaceEqual(dir, directory))) return [...dirs, directory]
     return dirs
   })
   const homedir = createMemo(() => globalSync.data.path.home)
@@ -330,12 +331,12 @@ export function DialogSelectFile(props: { mode?: DialogSelectFileMode; onOpenFil
     if (filesOnly()) {
       const files = await file.searchFiles(query)
       const category = language.t("palette.group.files")
-      return files.map((path) => createFileEntry(path, category))
+      return files.map((path) => createFileEntry(path, file.display(path), category))
     }
 
     const [files, nextSessions] = await Promise.all([file.searchFiles(query), Promise.resolve(sessions(query))])
     const category = language.t("palette.group.files")
-    const entries = files.map((path) => createFileEntry(path, category))
+    const entries = files.map((path) => createFileEntry(path, file.display(path), category))
     return [...commandEntries.list(), ...nextSessions, ...entries]
   }
 
@@ -409,9 +410,9 @@ export function DialogSelectFile(props: { mode?: DialogSelectFileMode; onOpenFil
                   <FileIcon node={{ path: item.path ?? "", type: "file" }} class="shrink-0 size-4" />
                   <div class="flex items-center text-14-regular">
                     <span class="text-text-weak whitespace-nowrap overflow-hidden overflow-ellipsis truncate min-w-0">
-                      {getDirectory(item.path ?? "")}
+                      {getDirectory(item.title)}
                     </span>
-                    <span class="text-text-strong whitespace-nowrap">{getFilename(item.path ?? "")}</span>
+                    <span class="text-text-strong whitespace-nowrap">{getFilename(item.title)}</span>
                   </div>
                 </div>
               </div>
diff --git a/packages/app/src/components/file-tree.test.ts b/packages/app/src/components/file-tree.test.ts
index 29e20b4807c5..c0a7f7816a6c 100644
--- a/packages/app/src/components/file-tree.test.ts
+++ b/packages/app/src/components/file-tree.test.ts
@@ -1,4 +1,5 @@
 import { beforeAll, describe, expect, mock, test } from "bun:test"
+import { filePathKey } from "@/context/file/path"
 
 let shouldListRoot: typeof import("./file-tree").shouldListRoot
 let shouldListExpanded: typeof import("./file-tree").shouldListExpanded
@@ -53,8 +54,8 @@ describe("file tree fetch discipline", () => {
   })
 
   test("allowed auto-expand picks only collapsed dirs", () => {
-    const expanded = new Set<string>()
-    const filter = { dirs: new Set(["src", "src/components"]) }
+    const expanded = new Set<ReturnType<typeof filePathKey>>()
+    const filter = { dirs: new Set([filePathKey("src"), filePathKey("src/components")]) }
 
     const first = dirsToExpand({
       level: 0,
@@ -62,7 +63,7 @@ describe("file tree fetch discipline", () => {
       expanded: (dir) => expanded.has(dir),
     })
 
-    expect(first).toEqual(["src", "src/components"])
+    expect(first.map(String)).toEqual(["src", "src/components"])
 
     for (const dir of first) expanded.add(dir)
 
diff --git a/packages/app/src/components/file-tree.tsx b/packages/app/src/components/file-tree.tsx
index 930832fb6555..d29c79966719 100644
--- a/packages/app/src/components/file-tree.tsx
+++ b/packages/app/src/components/file-tree.tsx
@@ -1,8 +1,17 @@
 import { useFile } from "@/context/file"
-import { encodeFilePath } from "@/context/file/path"
+import {
+  filePathAncestorKeys,
+  filePathEqual,
+  filePathFromKey,
+  filePathKey,
+  filePathName,
+  filePathParentKey,
+  type FilePathKey,
+} from "@/context/file/path"
 import { Collapsible } from "@opencode-ai/ui/collapsible"
 import { FileIcon } from "@opencode-ai/ui/file-icon"
 import { Icon } from "@opencode-ai/ui/icon"
+import { encodeFilePath, getPathRoot } from "@opencode-ai/util/path"
 import {
   createEffect,
   createMemo,
@@ -22,15 +31,18 @@ import type { FileNode } from "@opencode-ai/sdk/v2"
 
 const MAX_DEPTH = 128
 
-function pathToFileUrl(filepath: string): string {
-  return `file://${encodeFilePath(filepath)}`
+function pathToFileUrl(filepath: string) {
+  if (!getPathRoot(filepath)) return
+  const path = encodeFilePath(filepath)
+  if (path.startsWith("//")) return `file:${path}`
+  return `file://${path}`
 }
 
 type Kind = "add" | "del" | "mix"
 
 type Filter = {
-  files: Set<string>
-  dirs: Set<string>
+  files: Set<FilePathKey>
+  dirs: Set<FilePathKey>
 }
 
 export function shouldListRoot(input: { level: number; dir?: { loaded?: boolean; loading?: boolean } }) {
@@ -53,8 +65,8 @@ export function shouldListExpanded(input: {
 
 export function dirsToExpand(input: {
   level: number
-  filter?: { dirs: Set<string> }
-  expanded: (dir: string) => boolean
+  filter?: { dirs: Set<FilePathKey> }
+  expanded: (dir: FilePathKey) => boolean
 }) {
   if (input.level !== 0) return []
   if (!input.filter) return []
@@ -80,9 +92,10 @@ const kindDotColor = (kind: Kind) => {
 }
 
 const visibleKind = (node: FileNode, kinds?: ReadonlyMap<string, Kind>, marks?: Set<string>) => {
-  const kind = kinds?.get(node.path)
+  const key = filePathKey(node.path)
+  const kind = kinds?.get(key)
   if (!kind) return
-  if (!marks?.has(node.path)) return
+  if (!marks?.has(key)) return
   return kind
 }
 
@@ -148,7 +161,7 @@ const FileTreeNode = (
       component={local.as ?? "div"}
       classList={{
         "w-full min-w-0 h-6 flex items-center justify-start gap-x-1.5 rounded-md px-1.5 py-0 text-left hover:bg-surface-raised-base-hover active:bg-surface-base-active transition-colors cursor-pointer": true,
-        "bg-surface-base-active": local.node.path === local.active,
+        "bg-surface-base-active": filePathEqual(local.node.path, local.active),
         ...(local.classList ?? {}),
         [local.class ?? ""]: !!local.class,
         [local.nodeClass ?? ""]: !!local.nodeClass,
@@ -158,7 +171,8 @@ const FileTreeNode = (
       onDragStart={(event: DragEvent) => {
         if (!local.draggable) return
         event.dataTransfer?.setData("text/plain", `file:${local.node.path}`)
-        event.dataTransfer?.setData("text/uri-list", pathToFileUrl(local.node.path))
+        const url = pathToFileUrl(local.node.absolute)
+        if (url) event.dataTransfer?.setData("text/uri-list", url)
         if (event.dataTransfer) event.dataTransfer.effectAllowed = "copy"
         withFileDragImage(event)
       }}
@@ -204,20 +218,16 @@ export default function FileTree(props: {
   onFileClick?: (file: FileNode) => void
 
   _filter?: Filter
-  _marks?: Set<string>
-  _deeps?: Map<string, number>
+  _marks?: Set<FilePathKey>
+  _deeps?: Map<FilePathKey, number>
   _kinds?: ReadonlyMap<string, Kind>
-  _chain?: readonly string[]
+  _chain?: readonly FilePathKey[]
 }) {
   const file = useFile()
   const level = props.level ?? 0
   const draggable = () => props.draggable ?? true
 
-  const key = (p: string) =>
-    file
-      .normalize(p)
-      .replace(/[\\/]+$/, "")
-      .replaceAll("\\", "/")
+  const key = (p: string) => filePathKey(file.normalize(p))
   const chain = props._chain ? [...props._chain, key(props.path)] : [key(props.path)]
 
   const filter = createMemo(() => {
@@ -226,17 +236,8 @@ export default function FileTree(props: {
     const allowed = props.allowed
     if (!allowed) return
 
-    const files = new Set(allowed)
-    const dirs = new Set<string>()
-
-    for (const item of allowed) {
-      const parts = item.split("/")
-      const parents = parts.slice(0, -1)
-      for (const [idx] of parents.entries()) {
-        const dir = parents.slice(0, idx + 1).join("/")
-        if (dir) dirs.add(dir)
-      }
-    }
+    const files = new Set(allowed.map(filePathKey))
+    const dirs = new Set(allowed.flatMap((item) => filePathAncestorKeys(filePathKey(item))))
 
     return { files, dirs }
   })
@@ -244,9 +245,9 @@ export default function FileTree(props: {
   const marks = createMemo(() => {
     if (props._marks) return props._marks
 
-    const out = new Set<string>()
-    for (const item of props.modified ?? []) out.add(item)
-    for (const item of props.kinds?.keys() ?? []) out.add(item)
+    const out = new Set<FilePathKey>()
+    for (const item of props.modified ?? []) out.add(filePathKey(item))
+    for (const item of props.kinds?.keys() ?? []) out.add(filePathKey(item))
     if (out.size === 0) return
     return out
   })
@@ -259,12 +260,12 @@ export default function FileTree(props: {
   const deeps = createMemo(() => {
     if (props._deeps) return props._deeps
 
-    const out = new Map<string, number>()
+    const out = new Map<FilePathKey, number>()
 
     const root = props.path
     if (!(file.tree.state(root)?.expanded ?? false)) return out
 
-    const seen = new Set<string>()
+    const seen = new Set<FilePathKey>()
     const stack: { dir: string; lvl: number; i: number; kids: string[]; max: number }[] = []
 
     const push = (dir: string, lvl: number) => {
@@ -292,7 +293,7 @@ export default function FileTree(props: {
         continue
       }
 
-      out.set(top.dir, top.max)
+      out.set(key(top.dir), top.max)
       stack.pop()
 
       const parent = stack[stack.length - 1]
@@ -329,32 +330,22 @@ export default function FileTree(props: {
     const nodes = file.tree.children(props.path)
     const current = filter()
     if (!current) return nodes
-
-    const parent = (path: string) => {
-      const idx = path.lastIndexOf("/")
-      if (idx === -1) return ""
-      return path.slice(0, idx)
-    }
-
-    const leaf = (path: string) => {
-      const idx = path.lastIndexOf("/")
-      return idx === -1 ? path : path.slice(idx + 1)
-    }
+    const parent = key(props.path)
 
     const out = nodes.filter((node) => {
-      if (node.type === "file") return current.files.has(node.path)
-      return current.dirs.has(node.path)
+      if (node.type === "file") return current.files.has(filePathKey(node.path))
+      return current.dirs.has(filePathKey(node.path))
     })
 
-    const seen = new Set(out.map((node) => node.path))
+    const seen = new Set(out.map((node) => filePathKey(node.path)))
 
     for (const dir of current.dirs) {
-      if (parent(dir) !== props.path) continue
+      if (filePathParentKey(dir) !== parent) continue
       if (seen.has(dir)) continue
       out.push({
-        name: leaf(dir),
-        path: dir,
-        absolute: dir,
+        name: filePathName(dir),
+        path: filePathFromKey(dir),
+        absolute: filePathFromKey(dir),
         type: "directory",
         ignored: false,
       })
@@ -362,12 +353,12 @@ export default function FileTree(props: {
     }
 
     for (const item of current.files) {
-      if (parent(item) !== props.path) continue
+      if (filePathParentKey(item) !== parent) continue
       if (seen.has(item)) continue
       out.push({
-        name: leaf(item),
-        path: item,
-        absolute: item,
+        name: filePathName(item),
+        path: filePathFromKey(item),
+        absolute: filePathFromKey(item),
         type: "file",
         ignored: false,
       })
@@ -389,7 +380,7 @@ export default function FileTree(props: {
       <For each={nodes()}>
         {(node) => {
           const expanded = () => file.tree.state(node.path)?.expanded ?? false
-          const deep = () => deeps().get(node.path) ?? -1
+          const deep = () => deeps().get(key(node.path)) ?? -1
           const kind = () => visibleKind(node, kinds(), marks())
           const active = () => !!kind() && !node.ignored
 
diff --git a/packages/app/src/components/prompt-input.tsx b/packages/app/src/components/prompt-input.tsx
index f3d3e135deac..905c4ffd8b09 100644
--- a/packages/app/src/components/prompt-input.tsx
+++ b/packages/app/src/components/prompt-input.tsx
@@ -37,6 +37,7 @@ import { usePlatform } from "@/context/platform"
 import { useSessionLayout } from "@/pages/session/session-layout"
 import { createSessionTabs } from "@/pages/session/helpers"
 import { promptEnabled, promptProbe } from "@/testing/prompt"
+import { filePathEqual, filePathKey } from "@/context/file/path"
 import { createTextFragment, getCursorPosition, setCursorPosition, setRangeEdge } from "./prompt-input/editor-dom"
 import { createPromptAttachments } from "./prompt-input/attachments"
 import { ACCEPTED_FILE_TYPES } from "./prompt-input/files"
@@ -167,7 +168,7 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
   const activeFileTab = createSessionTabs({
     tabs,
     pathFromTab: files.pathFromTab,
-    normalizeTab: (tab) => (tab.startsWith("file://") ? files.tab(tab) : tab),
+    normalizeTab: files.normalizeTab,
   }).activeFileTab
 
   const commentInReview = (path: string) => {
@@ -176,7 +177,7 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
 
     const diffs = sync.data.session_diff[sessionID]
     if (!diffs) return false
-    return diffs.some((diff) => diff.file === path)
+    return diffs.some((diff) => filePathEqual(diff.file, path))
   }
 
   const openComment = (item: { path: string; commentID?: string; commentOrigin?: "review" | "file" }) => {
@@ -193,7 +194,7 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
           requestAnimationFrame(() => {
             const current = comments.focus()
             if (!current) return
-            if (current.file !== focus.file || current.id !== focus.id) return
+            if (!filePathEqual(current.file, focus.file) || current.id !== focus.id) return
             schedule(left - 1)
           })
         })
@@ -229,8 +230,9 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
     for (const tab of order) {
       const path = files.pathFromTab(tab)
       if (!path) continue
-      if (seen.has(path)) continue
-      seen.add(path)
+      const key = filePathKey(path)
+      if (seen.has(key)) continue
+      seen.add(key)
       paths.push(path)
     }
 
@@ -343,13 +345,13 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
   )
 
   const historyComments = () => {
-    const byID = new Map(comments.all().map((item) => [`${item.file}\n${item.id}`, item] as const))
+    const byID = new Map(comments.all().map((item) => [`${filePathKey(item.file)}\n${item.id}`, item] as const))
     return prompt.context.items().flatMap((item) => {
       if (item.type !== "file") return []
       const comment = item.comment?.trim()
       if (!comment) return []
 
-      const selection = item.commentID ? byID.get(`${item.path}\n${item.commentID}`)?.selection : undefined
+      const selection = item.commentID ? byID.get(`${filePathKey(item.path)}\n${item.commentID}`)?.selection : undefined
       const nextSelection =
         selection ??
         (item.selection
@@ -366,7 +368,7 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
           path: item.path,
           selection: { ...nextSelection },
           comment,
-          time: item.commentID ? (byID.get(`${item.path}\n${item.commentID}`)?.time ?? Date.now()) : Date.now(),
+          time: item.commentID ? (byID.get(`${filePathKey(item.path)}\n${item.commentID}`)?.time ?? Date.now()) : Date.now(),
           origin: item.commentOrigin,
           preview: item.preview,
         } satisfies PromptHistoryComment,
@@ -557,7 +559,7 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
 
   const atKey = (x: AtOption | undefined) => {
     if (!x) return ""
-    return x.type === "agent" ? `agent:${x.name}` : `file:${x.path}`
+    return x.type === "agent" ? `agent:${x.name}` : `file:${filePathKey(x.path)}`
   }
 
   const {
@@ -570,12 +572,17 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
     items: async (query) => {
       const agents = agentList()
       const open = recent()
-      const seen = new Set(open)
-      const pinned: AtOption[] = open.map((path) => ({ type: "file", path, display: path, recent: true }))
+      const seen = new Set(open.map(filePathKey))
+      const pinned: AtOption[] = open.map((path) => ({
+        type: "file",
+        path,
+        display: files.display(path),
+        recent: true,
+      }))
       const paths = await files.searchFilesAndDirectories(query)
       const fileOptions: AtOption[] = paths
-        .filter((path) => !seen.has(path))
-        .map((path) => ({ type: "file", path, display: path }))
+        .filter((path) => !seen.has(filePathKey(path)))
+        .map((path) => ({ type: "file", path, display: files.display(path) }))
       return [...agents, ...pinned, ...fileOptions]
     },
     key: atKey,
@@ -1293,7 +1300,7 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
           items={contextItems()}
           active={(item) => {
             const active = comments.active()
-            return !!item.commentID && item.commentID === active?.id && item.path === active?.file
+            return !!item.commentID && item.commentID === active?.id && filePathEqual(item.path, active?.file)
           }}
           openComment={openComment}
           remove={(item) => {
diff --git a/packages/app/src/components/prompt-input/build-request-parts.ts b/packages/app/src/components/prompt-input/build-request-parts.ts
index 4146fb4847fc..4e7a90e0628a 100644
--- a/packages/app/src/components/prompt-input/build-request-parts.ts
+++ b/packages/app/src/components/prompt-input/build-request-parts.ts
@@ -1,7 +1,6 @@
-import { getFilename } from "@opencode-ai/util/path"
+import { encodeFilePath, getFilename, resolveWorkspacePath } from "@opencode-ai/util/path"
 import { type AgentPartInput, type FilePartInput, type Part, type TextPartInput } from "@opencode-ai/sdk/v2/client"
 import type { FileSelection } from "@/context/file"
-import { encodeFilePath } from "@/context/file/path"
 import type { AgentPart, FileAttachmentPart, ImageAttachmentPart, Prompt } from "@/context/prompt"
 import { Identifier } from "@/utils/id"
 import { createCommentMetadata, formatCommentNote } from "@/utils/comment-note"
@@ -29,13 +28,6 @@ type BuildRequestPartsInput = {
   sessionDirectory: string
 }
 
-const absolute = (directory: string, path: string) => {
-  if (path.startsWith("/")) return path
-  if (/^[A-Za-z]:[\\/]/.test(path) || /^[A-Za-z]:$/.test(path)) return path
-  if (path.startsWith("\\\\") || path.startsWith("//")) return path
-  return `${directory.replace(/[\\/]+$/, "")}/${path}`
-}
-
 const fileQuery = (selection: FileSelection | undefined) =>
   selection ? `?start=${selection.startLine}&end=${selection.endLine}` : ""
 
@@ -88,7 +80,7 @@ export function buildRequestParts(input: BuildRequestPartsInput) {
   ]
 
   const files = input.prompt.filter(isFileAttachment).map((attachment) => {
-    const path = absolute(input.sessionDirectory, attachment.path)
+    const path = resolveWorkspacePath(input.sessionDirectory, attachment.path)
     return {
       id: Identifier.ascending("part"),
       type: "file",
@@ -122,7 +114,7 @@ export function buildRequestParts(input: BuildRequestPartsInput) {
 
   const used = new Set(files.map((part) => part.url))
   const context = input.context.flatMap((item) => {
-    const path = absolute(input.sessionDirectory, item.path)
+    const path = resolveWorkspacePath(input.sessionDirectory, item.path)
     const url = `file://${encodeFilePath(path)}${fileQuery(item.selection)}`
     const comment = item.comment?.trim()
     if (!comment && used.has(url)) return []
diff --git a/packages/app/src/components/prompt-input/context-items.tsx b/packages/app/src/components/prompt-input/context-items.tsx
index b138fe3ef690..0529f5273aa0 100644
--- a/packages/app/src/components/prompt-input/context-items.tsx
+++ b/packages/app/src/components/prompt-input/context-items.tsx
@@ -3,6 +3,7 @@ import { FileIcon } from "@opencode-ai/ui/file-icon"
 import { IconButton } from "@opencode-ai/ui/icon-button"
 import { Tooltip } from "@opencode-ai/ui/tooltip"
 import { getDirectory, getFilename, getFilenameTruncated } from "@opencode-ai/util/path"
+import { useFile } from "@/context/file"
 import type { ContextItem } from "@/context/prompt"
 
 type PromptContextItem = ContextItem & { key: string }
@@ -16,14 +17,17 @@ type ContextItemsProps = {
 }
 
 export const PromptContextItems: Component<ContextItemsProps> = (props) => {
+  const file = useFile()
+
   return (
     <Show when={props.items.length > 0}>
       <div class="flex flex-nowrap items-start gap-2 p-2 overflow-x-auto no-scrollbar">
         <For each={props.items}>
           {(item) => {
-            const directory = getDirectory(item.path)
-            const filename = getFilename(item.path)
-            const label = getFilenameTruncated(item.path, 14)
+            const path = file.display(item.path)
+            const directory = getDirectory(path)
+            const filename = getFilename(path)
+            const label = getFilenameTruncated(path, 14)
             const selected = props.active(item)
 
             return (
diff --git a/packages/app/src/components/prompt-input/history.test.ts b/packages/app/src/components/prompt-input/history.test.ts
index 37b5ce196279..f2f29115f5d0 100644
--- a/packages/app/src/components/prompt-input/history.test.ts
+++ b/packages/app/src/components/prompt-input/history.test.ts
@@ -39,6 +39,10 @@ describe("prompt-input history", () => {
 
     const dedupedComments = prependHistoryEntry(commentsOnly, DEFAULT_PROMPT, [comment("c1")])
     expect(dedupedComments).toBe(commentsOnly)
+
+    const withSlash = prependHistoryEntry([], [{ type: "file", path: "src\\a.ts", content: "@a", start: 0, end: 2 }])
+    const dedupedSlash = prependHistoryEntry(withSlash, [{ type: "file", path: "src/a.ts", content: "@a", start: 0, end: 2 }])
+    expect(dedupedSlash).toBe(withSlash)
   })
 
   test("navigatePromptHistory restores saved prompt when moving down from newest", () => {
@@ -95,6 +99,12 @@ describe("prompt-input history", () => {
     expect(up.entry.comments).toEqual([comment("c1")])
   })
 
+  test("comment equality ignores slash variants", () => {
+    const first = prependHistoryEntry([], DEFAULT_PROMPT, [comment("c1")])
+    const second = prependHistoryEntry(first, DEFAULT_PROMPT, [{ ...comment("c1"), path: "src\\a.ts" }])
+    expect(second).toBe(first)
+  })
+
   test("normalizePromptHistoryEntry supports legacy prompt arrays", () => {
     const entry = normalizePromptHistoryEntry(text("legacy"))
     expect(entry.prompt[0]?.type === "text" ? entry.prompt[0].content : "").toBe("legacy")
diff --git a/packages/app/src/components/prompt-input/history.ts b/packages/app/src/components/prompt-input/history.ts
index de62653211dd..7e1e3fc71bb3 100644
--- a/packages/app/src/components/prompt-input/history.ts
+++ b/packages/app/src/components/prompt-input/history.ts
@@ -1,5 +1,6 @@
 import type { Prompt } from "@/context/prompt"
 import type { SelectedLineRange } from "@/context/file"
+import { filePathEqual } from "@/context/file/path"
 
 const DEFAULT_PROMPT: Prompt = [{ type: "text", content: "", start: 0, end: 0 }]
 
@@ -101,7 +102,7 @@ export function prependHistoryEntry(
 
 function isCommentEqual(commentA: PromptHistoryComment, commentB: PromptHistoryComment) {
   return (
-    commentA.path === commentB.path &&
+    filePathEqual(commentA.path, commentB.path) &&
     commentA.comment === commentB.comment &&
     commentA.origin === commentB.origin &&
     commentA.preview === commentB.preview &&
@@ -122,7 +123,7 @@ function isPromptEqual(promptA: PromptHistoryStoredEntry, promptB: PromptHistory
     if (partA.type !== partB.type) return false
     if (partA.type === "text" && partA.content !== (partB.type === "text" ? partB.content : "")) return false
     if (partA.type === "file") {
-      if (partA.path !== (partB.type === "file" ? partB.path : "")) return false
+      if (!filePathEqual(partA.path, partB.type === "file" ? partB.path : "")) return false
       const a = partA.selection
       const b = partB.type === "file" ? partB.selection : undefined
       const sameSelection =
diff --git a/packages/app/src/components/prompt-input/slash-popover.tsx b/packages/app/src/components/prompt-input/slash-popover.tsx
index 65eb01c797b8..4fd22ab62e78 100644
--- a/packages/app/src/components/prompt-input/slash-popover.tsx
+++ b/packages/app/src/components/prompt-input/slash-popover.tsx
@@ -70,8 +70,8 @@ export const PromptPopover: Component<PromptPopoverProps> = (props) => {
                   }
 
                   const isDirectory = item.path.endsWith("/")
-                  const directory = isDirectory ? item.path : getDirectory(item.path)
-                  const filename = isDirectory ? "" : getFilename(item.path)
+                  const directory = isDirectory ? item.display : getDirectory(item.display)
+                  const filename = isDirectory ? "" : getFilename(item.display)
 
                   return (
                     <button
diff --git a/packages/app/src/components/session-context-usage.tsx b/packages/app/src/components/session-context-usage.tsx
index 7379833f8b84..36aa5cd31e95 100644
--- a/packages/app/src/components/session-context-usage.tsx
+++ b/packages/app/src/components/session-context-usage.tsx
@@ -38,7 +38,7 @@ export function SessionContextUsage(props: SessionContextUsageProps) {
   const tabState = createSessionTabs({
     tabs,
     pathFromTab: file.pathFromTab,
-    normalizeTab: (tab) => (tab.startsWith("file://") ? file.tab(tab) : tab),
+    normalizeTab: file.normalizeTab,
   })
   const messages = createMemo(() => (params.id ? (sync.data.message[params.id] ?? []) : []))
 
diff --git a/packages/app/src/components/session/session-header.tsx b/packages/app/src/components/session/session-header.tsx
index 495b32340580..e0ff146ec37e 100644
--- a/packages/app/src/components/session/session-header.tsx
+++ b/packages/app/src/components/session/session-header.tsx
@@ -14,10 +14,11 @@ import { Portal } from "solid-js/web"
 import { useCommand } from "@/context/command"
 import { useLanguage } from "@/context/language"
 import { useLayout } from "@/context/layout"
-import { usePlatform } from "@/context/platform"
+import { serverOS, usePlatform } from "@/context/platform"
 import { useServer } from "@/context/server"
 import { useSync } from "@/context/sync"
 import { useTerminal } from "@/context/terminal"
+import { findProjectByDirectory } from "@/pages/layout/helpers"
 import { focusTerminalById } from "@/pages/session/helpers"
 import { useSessionLayout } from "@/pages/session/session-layout"
 import { messageAgentColor } from "@/utils/agent"
@@ -43,7 +44,6 @@ const OPEN_APPS = [
 ] as const
 
 type OpenApp = (typeof OPEN_APPS)[number]
-type OS = "macos" | "windows" | "linux" | "unknown"
 
 const MAC_APPS = [
   {
@@ -110,16 +110,6 @@ const LINUX_APPS = [
   },
 ] as const
 
-const detectOS = (platform: ReturnType<typeof usePlatform>): OS => {
-  if (platform.platform === "desktop" && platform.os) return platform.os
-  if (typeof navigator !== "object") return "unknown"
-  const value = navigator.platform || navigator.userAgent
-  if (/Mac/i.test(value)) return "macos"
-  if (/Win/i.test(value)) return "windows"
-  if (/Linux/i.test(value)) return "linux"
-  return "unknown"
-}
-
 const showRequestError = (language: ReturnType<typeof useLanguage>, err: unknown) => {
   showToast({
     variant: "error",
@@ -142,7 +132,7 @@ export function SessionHeader() {
   const project = createMemo(() => {
     const directory = projectDirectory()
     if (!directory) return
-    return layout.projects.list().find((p) => p.worktree === directory || p.sandboxes?.includes(directory))
+    return findProjectByDirectory(layout.projects.list(), directory)
   })
   const name = createMemo(() => {
     const current = project()
@@ -150,7 +140,10 @@ export function SessionHeader() {
     return getFilename(projectDirectory())
   })
   const hotkey = createMemo(() => command.keybind("file.open"))
-  const os = createMemo(() => detectOS(platform))
+  const canOpen = createMemo(() => platform.platform === "desktop" && !!platform.openPath && server.isLocal())
+  const os = createMemo(() =>
+    serverOS(sync.data.path.directory ? sync.data.path : undefined, canOpen() ? platform : undefined),
+  )
 
   const [exists, setExists] = createStore<Partial<Record<OpenApp, boolean>>>({
     finder: true,
@@ -169,7 +162,7 @@ export function SessionHeader() {
   })
 
   createEffect(() => {
-    if (platform.platform !== "desktop") return
+    if (!canOpen()) return
     if (!platform.checkAppExists) return
 
     const list = apps()
@@ -213,7 +206,6 @@ export function SessionHeader() {
     app: undefined as OpenApp | undefined,
   })
 
-  const canOpen = createMemo(() => platform.platform === "desktop" && !!platform.openPath && server.isLocal())
   const current = createMemo(
     () =>
       options().find((o) => o.id === prefs.app) ??
diff --git a/packages/app/src/context/comments.test.ts b/packages/app/src/context/comments.test.ts
index 82fa170f2fc7..36b267e2ef7a 100644
--- a/packages/app/src/context/comments.test.ts
+++ b/packages/app/src/context/comments.test.ts
@@ -183,4 +183,25 @@ describe("comments session indexing", () => {
       dispose()
     })
   })
+
+  test("matches list, update, and remove across slash variants", () => {
+    createRoot((dispose) => {
+      const comments = createCommentSessionForTest({
+        "src\\a.ts": [line("src\\a.ts", "a1", 10)],
+      })
+
+      expect(comments.list("src/a.ts").map((item) => item.file)).toEqual(["src/a.ts"])
+
+      comments.update("src/a.ts", "a1", "edited")
+      expect(comments.list("src\\a.ts")[0]?.comment).toBe("edited")
+
+      comments.setFocus({ file: "src/a.ts", id: "a1" })
+      comments.remove("src/a.ts", "a1")
+
+      expect(comments.list("src\\a.ts")).toEqual([])
+      expect(comments.focus()).toBeNull()
+
+      dispose()
+    })
+  })
 })
diff --git a/packages/app/src/context/comments.tsx b/packages/app/src/context/comments.tsx
index a97010c0af38..d7ec8cbf16fd 100644
--- a/packages/app/src/context/comments.tsx
+++ b/packages/app/src/context/comments.tsx
@@ -4,42 +4,41 @@ import { createSimpleContext } from "@opencode-ai/ui/context"
 import { useParams } from "@solidjs/router"
 import { Persist, persisted } from "@/utils/persist"
 import { createScopedCache } from "@/utils/scoped-cache"
+import { sessionScopeKey, sessionScopeParts } from "@/utils/session-key"
 import { uuid } from "@/utils/uuid"
 import type { SelectedLineRange } from "@/context/file"
+import { filePathKey, normalizeFilePath, type FilePath, type FilePathKey } from "@/context/file/path"
 
 export type LineComment = {
   id: string
-  file: string
+  file: FilePath
   selection: SelectedLineRange
   comment: string
   time: number
 }
 
-type CommentFocus = { file: string; id: string }
+type CommentFocus = { file: FilePath; id: string }
 
-const WORKSPACE_KEY = "__workspace__"
 const MAX_COMMENT_SESSIONS = 20
 
-function sessionKey(dir: string, id: string | undefined) {
-  return `${dir}\n${id ?? WORKSPACE_KEY}`
+type CommentStore = {
+  comments: Record<FilePathKey, LineComment[]>
 }
 
-function decodeSessionKey(key: string) {
-  const split = key.lastIndexOf("\n")
-  if (split < 0) return { dir: key, id: WORKSPACE_KEY }
-  return {
-    dir: key.slice(0, split),
-    id: key.slice(split + 1),
-  }
-}
+const record = (value: unknown): value is Record<string, unknown> =>
+  typeof value === "object" && value !== null && !Array.isArray(value)
 
-type CommentStore = {
-  comments: Record<string, LineComment[]>
-}
+const text = (value: unknown) => (typeof value === "string" ? value : undefined)
+
+const num = (value: unknown) => (typeof value === "number" && Number.isFinite(value) ? value : undefined)
 
-function aggregate(comments: Record<string, LineComment[]>) {
-  return Object.keys(comments)
-    .flatMap((file) => comments[file] ?? [])
+const normalizeFile = (file: FilePath) => normalizeFilePath(file)
+
+const commentKey = (file: FilePath) => filePathKey(file)
+
+function aggregate(comments: Record<FilePathKey, LineComment[]>) {
+  return Object.values(comments)
+    .flatMap((items) => items.map(cloneComment))
     .slice()
     .sort((a, b) => a.time - b.time)
 }
@@ -58,19 +57,70 @@ function cloneSelection(selection: SelectedLineRange): SelectedLineRange {
 function cloneComment(comment: LineComment): LineComment {
   return {
     ...comment,
+    file: normalizeFile(comment.file),
     selection: cloneSelection(comment.selection),
   }
 }
 
+function lineComment(value: unknown): LineComment | undefined {
+  if (!record(value)) return
+  const id = text(value.id)
+  const file = text(value.file)
+  const comment = text(value.comment)
+  const time = num(value.time)
+  if (!id || !file || comment === undefined || time === undefined) return
+  if (!record(value.selection)) return
+  const start = num(value.selection.start)
+  const end = num(value.selection.end)
+  if (start === undefined || end === undefined) return
+  const side = value.selection.side === "additions" || value.selection.side === "deletions" ? value.selection.side : undefined
+  const endSide =
+    value.selection.endSide === "additions" || value.selection.endSide === "deletions"
+      ? value.selection.endSide
+      : undefined
+  return cloneComment({
+    id,
+    file,
+    comment,
+    time,
+    selection: { start, end, ...(side ? { side } : {}), ...(endSide ? { endSide } : {}) },
+  })
+}
+
+function normalizeCommentMap(value: unknown) {
+  if (!record(value)) return {} as Record<FilePathKey, LineComment[]>
+
+  return Object.entries(value).reduce<Record<FilePathKey, LineComment[]>>((acc, [name, items]) => {
+    if (!Array.isArray(items)) return acc
+    const key = commentKey(name)
+    const next = items.map(lineComment).filter((item): item is LineComment => !!item)
+    if (next.length === 0) return acc
+    acc[key] = [...(acc[key] ?? []), ...next]
+    return acc
+  }, {})
+}
+
+export function migrateCommentStore(value: unknown) {
+  if (!record(value)) return value
+  if (!record(value.comments)) return value
+
+  const comments = normalizeCommentMap(value.comments)
+  return {
+    ...value,
+    comments,
+  }
+}
+
 function group(comments: LineComment[]) {
-  return comments.reduce<Record<string, LineComment[]>>((acc, comment) => {
-    const list = acc[comment.file]
+  return comments.reduce<Record<FilePathKey, LineComment[]>>((acc, comment) => {
+    const key = commentKey(comment.file)
+    const list = acc[key]
     const next = cloneComment(comment)
     if (list) {
       list.push(next)
       return acc
     }
-    acc[comment.file] = [next]
+    acc[key] = [next]
     return acc
   }, {})
 }
@@ -83,10 +133,13 @@ function createCommentSessionState(store: Store<CommentStore>, setStore: SetStor
 
   const all = () => aggregate(store.comments)
 
+  const normalizeFocus = (value: CommentFocus | null) => (value ? { ...value, file: normalizeFile(value.file) } : null)
+
   const setRef = (
     key: "focus" | "active",
     value: CommentFocus | null | ((value: CommentFocus | null) => CommentFocus | null),
-  ) => setState(key, value)
+  ) =>
+    setState(key, (current) => normalizeFocus(typeof value === "function" ? value(current) : value))
 
   const setFocus = (value: CommentFocus | null | ((value: CommentFocus | null) => CommentFocus | null)) =>
     setRef("focus", value)
@@ -94,33 +147,44 @@ function createCommentSessionState(store: Store<CommentStore>, setStore: SetStor
   const setActive = (value: CommentFocus | null | ((value: CommentFocus | null) => CommentFocus | null)) =>
     setRef("active", value)
 
-  const list = (file: string) => store.comments[file] ?? []
+  const list = (file: FilePath) => {
+    return store.comments[commentKey(file)]?.map(cloneComment) ?? []
+  }
 
   const add = (input: Omit<LineComment, "id" | "time">) => {
+    const key = commentKey(input.file)
+    const file = store.comments[key]?.[0]?.file ?? normalizeFile(input.file)
     const next: LineComment = {
       id: uuid(),
       time: Date.now(),
       ...input,
+      file,
       selection: cloneSelection(input.selection),
     }
 
     batch(() => {
-      setStore("comments", input.file, (items) => [...(items ?? []), next])
-      setFocus({ file: input.file, id: next.id })
+      setStore("comments", key, (items) => [...(items ?? []), next])
+      setFocus({ file, id: next.id })
     })
 
     return next
   }
 
-  const remove = (file: string, id: string) => {
+  const remove = (file: FilePath, id: string) => {
+    const key = commentKey(file)
+
     batch(() => {
-      setStore("comments", file, (items) => (items ?? []).filter((item) => item.id !== id))
-      setFocus((current) => (current?.file === file && current.id === id ? null : current))
+      setStore("comments", key, (items) => (items ?? []).filter((item) => item.id !== id))
+      setFocus((current) =>
+        current && commentKey(current.file) === key && current.id === id ? null : current,
+      )
     })
   }
 
-  const update = (file: string, id: string, comment: string) => {
-    setStore("comments", file, (items) =>
+  const update = (file: FilePath, id: string, comment: string) => {
+    const key = commentKey(file)
+
+    setStore("comments", key, (items) =>
       (items ?? []).map((item) => {
         if (item.id !== id) return item
         return { ...item, comment }
@@ -162,15 +226,16 @@ function createCommentSessionState(store: Store<CommentStore>, setStore: SetStor
 }
 
 export function createCommentSessionForTest(comments: Record<string, LineComment[]> = {}) {
-  const [store, setStore] = createStore<CommentStore>({ comments })
+  const [store, setStore] = createStore<CommentStore>({ comments: normalizeCommentMap(comments) })
   return createCommentSessionState(store, setStore)
 }
 
 function createCommentSession(dir: string, id: string | undefined) {
-  const legacy = `${dir}/comments${id ? "/" + id : ""}.v1`
-
   const [store, setStore, _, ready] = persisted(
-    Persist.scoped(dir, id, "comments", [legacy]),
+    {
+      ...Persist.scoped(dir, id, "comments", Persist.legacyScoped(dir, id, "comments", "v1")),
+      migrate: migrateCommentStore,
+    },
     createStore<CommentStore>({
       comments: {},
     }),
@@ -202,9 +267,9 @@ export const { use: useComments, provider: CommentsProvider } = createSimpleCont
     const params = useParams()
     const cache = createScopedCache(
       (key) => {
-        const decoded = decodeSessionKey(key)
+        const decoded = sessionScopeParts(key)
         return createRoot((dispose) => ({
-          value: createCommentSession(decoded.dir, decoded.id === WORKSPACE_KEY ? undefined : decoded.id),
+          value: createCommentSession(decoded.dir, decoded.id),
           dispose,
         }))
       },
@@ -217,7 +282,7 @@ export const { use: useComments, provider: CommentsProvider } = createSimpleCont
     onCleanup(() => cache.clear())
 
     const load = (dir: string, id: string | undefined) => {
-      const key = sessionKey(dir, id)
+      const key = sessionScopeKey(dir, id)
       return cache.get(key).value
     }
 
@@ -225,11 +290,11 @@ export const { use: useComments, provider: CommentsProvider } = createSimpleCont
 
     return {
       ready: () => session().ready(),
-      list: (file: string) => session().list(file),
+      list: (file: FilePath) => session().list(file),
       all: () => session().all(),
       add: (input: Omit<LineComment, "id" | "time">) => session().add(input),
-      remove: (file: string, id: string) => session().remove(file, id),
-      update: (file: string, id: string, comment: string) => session().update(file, id, comment),
+      remove: (file: FilePath, id: string) => session().remove(file, id),
+      update: (file: FilePath, id: string, comment: string) => session().update(file, id, comment),
       replace: (comments: LineComment[]) => session().replace(comments),
       clear: () => session().clear(),
       focus: () => session().focus(),
diff --git a/packages/app/src/context/file.tsx b/packages/app/src/context/file.tsx
index f8fec7142d81..fd0d9975070d 100644
--- a/packages/app/src/context/file.tsx
+++ b/packages/app/src/context/file.tsx
@@ -8,7 +8,8 @@ import { useSDK } from "./sdk"
 import { useSync } from "./sync"
 import { useLanguage } from "@/context/language"
 import { useLayout } from "@/context/layout"
-import { createPathHelpers } from "./file/path"
+import { sessionKey } from "@/utils/session-key"
+import { createPathHelpers, filePathKey, workspacePathKey, type FilePath, type FilePathKey } from "./file/path"
 import {
   approxBytes,
   evictContentLru,
@@ -61,17 +62,20 @@ export const { use: useFile, provider: FileProvider } = createSimpleContext({
 
     const scope = createMemo(() => sdk.directory)
     const path = createPathHelpers(scope)
-    const tabs = layout.tabs(() => `${params.dir}${params.id ? "/" + params.id : ""}`)
+    const tabs = layout.tabs(() => sessionKey(params.dir ?? "", params.id))
+    const fileKey = (file: FilePath) => filePathKey(file)
+    const loadKey = (directory: string, file: FilePath) => `${workspacePathKey(directory)}\n${fileKey(file)}`
 
     const inflight = new Map<string, Promise<void>>()
     const [store, setStore] = createStore<{
-      file: Record<string, FileState>
+      file: Record<FilePathKey, FileState>
     }>({
       file: {},
     })
 
     const tree = createFileTreeStore({
       scope,
+      normalize: path.normalize,
       normalizeDir: path.normalizeDir,
       list: (dir) => sdk.client.file.list({ path: dir }).then((x) => x.data ?? []),
       onError: (message) => {
@@ -85,10 +89,11 @@ export const { use: useFile, provider: FileProvider } = createSimpleContext({
 
     const evictContent = (keep?: Set<string>) => {
       evictContentLru(keep, (target) => {
-        if (!store.file[target]) return
+        const key = fileKey(target as FilePath)
+        if (!store.file[key]) return
         setStore(
           "file",
-          target,
+          key,
           produce((draft) => {
             draft.content = undefined
             draft.loaded = false
@@ -110,16 +115,18 @@ export const { use: useFile, provider: FileProvider } = createSimpleContext({
     const viewCache = createFileViewCache()
     const view = createMemo(() => viewCache.load(scope(), params.id))
 
-    const ensure = (file: string) => {
+    const ensure = (file: FilePath) => {
       if (!file) return
-      if (store.file[file]) return
-      setStore("file", file, { path: file, name: getFilename(file) })
+      const key = fileKey(file)
+      if (store.file[key]) return
+      setStore("file", key, { path: file, name: getFilename(file) })
     }
 
-    const setLoading = (file: string) => {
+    const setLoading = (file: FilePath) => {
+      const key = fileKey(file)
       setStore(
         "file",
-        file,
+        key,
         produce((draft) => {
           draft.loading = true
           draft.error = undefined
@@ -127,10 +134,11 @@ export const { use: useFile, provider: FileProvider } = createSimpleContext({
       )
     }
 
-    const setLoaded = (file: string, content: FileState["content"]) => {
+    const setLoaded = (file: FilePath, content: FileState["content"]) => {
+      const key = fileKey(file)
       setStore(
         "file",
-        file,
+        key,
         produce((draft) => {
           draft.loaded = true
           draft.loading = false
@@ -139,10 +147,11 @@ export const { use: useFile, provider: FileProvider } = createSimpleContext({
       )
     }
 
-    const setLoadError = (file: string, message: string) => {
+    const setLoadError = (file: FilePath, message: string) => {
+      const key = fileKey(file)
       setStore(
         "file",
-        file,
+        key,
         produce((draft) => {
           draft.loading = false
           draft.error = message
@@ -155,15 +164,12 @@ export const { use: useFile, provider: FileProvider } = createSimpleContext({
       })
     }
 
-    const load = (input: string, options?: { force?: boolean }) => {
-      const file = path.normalize(input)
-      if (!file) return Promise.resolve()
-
+    const loadFile = (file: FilePath, options?: { force?: boolean }) => {
       const directory = scope()
-      const key = `${directory}\n${file}`
+      const key = loadKey(directory, file)
       ensure(file)
 
-      const current = store.file[file]
+      const current = store.file[fileKey(file)]
       if (!options?.force && current?.loaded) return Promise.resolve()
 
       const pending = inflight.get(key)
@@ -194,31 +200,39 @@ export const { use: useFile, provider: FileProvider } = createSimpleContext({
       return promise
     }
 
+    const load = (input: string, options?: { force?: boolean }) => loadFile(path.normalize(input), options)
+
     const search = (query: string, dirs: "true" | "false") =>
       sdk.client.find.files({ query, dirs }).then(
         (x) => (x.data ?? []).map(path.normalize),
         () => [],
       )
 
+    const openFile = (key: FilePathKey) => {
+      for (const tab of tabs.all()) {
+        const file = path.pathFromTab(tab)
+        if (!file || fileKey(file) !== key) continue
+        return file
+      }
+    }
+
     const stop = sdk.event.listen((e) => {
       invalidateFromWatcher(e.details, {
         normalize: path.normalize,
-        hasFile: (file) => Boolean(store.file[file]),
-        isOpen: (file) => tabs.all().some((tab) => path.pathFromTab(tab) === file),
+        file: (key) => store.file[key]?.path,
+        open: openFile,
+        dir: tree.dirPathByKey,
         loadFile: (file) => {
-          void load(file, { force: true })
+          void loadFile(file, { force: true })
         },
-        node: tree.node,
-        isDirLoaded: tree.isLoaded,
         refreshDir: (dir) => {
           void tree.listDir(dir, { force: true })
         },
       })
     })
 
-    const get = (input: string) => {
-      const file = path.normalize(input)
-      const state = store.file[file]
+    const getFile = (file: FilePath) => {
+      const state = store.file[fileKey(file)]
       const content = state?.content
       if (!content) return state
       if (hasFileContent(file)) {
@@ -229,16 +243,18 @@ export const { use: useFile, provider: FileProvider } = createSimpleContext({
       return state
     }
 
-    function withPath(input: string, action: (file: string) => unknown) {
+    const get = (input: string) => getFile(path.normalize(input))
+
+    function withFile<T>(input: string, action: (file: FilePath) => T) {
       return action(path.normalize(input))
     }
-    const scrollTop = (input: string) => withPath(input, (file) => view().scrollTop(file))
-    const scrollLeft = (input: string) => withPath(input, (file) => view().scrollLeft(file))
-    const selectedLines = (input: string) => withPath(input, (file) => view().selectedLines(file))
-    const setScrollTop = (input: string, top: number) => withPath(input, (file) => view().setScrollTop(file, top))
-    const setScrollLeft = (input: string, left: number) => withPath(input, (file) => view().setScrollLeft(file, left))
+    const scrollTop = (input: string) => withFile(input, (file) => view().scrollTop(file))
+    const scrollLeft = (input: string) => withFile(input, (file) => view().scrollLeft(file))
+    const selectedLines = (input: string) => withFile(input, (file) => view().selectedLines(file))
+    const setScrollTop = (input: string, top: number) => withFile(input, (file) => view().setScrollTop(file, top))
+    const setScrollLeft = (input: string, left: number) => withFile(input, (file) => view().setScrollLeft(file, left))
     const setSelectedLines = (input: string, range: SelectedLineRange | null) =>
-      withPath(input, (file) => view().setSelectedLines(file, range))
+      withFile(input, (file) => view().setSelectedLines(file, range))
 
     onCleanup(() => {
       stop()
@@ -248,7 +264,9 @@ export const { use: useFile, provider: FileProvider } = createSimpleContext({
     return {
       ready: () => view().ready(),
       normalize: path.normalize,
+      display: path.display,
       tab: path.tab,
+      normalizeTab: path.normalizeTab,
       pathFromTab: path.pathFromTab,
       tree: {
         list: tree.listDir,
diff --git a/packages/app/src/context/file/path.test.ts b/packages/app/src/context/file/path.test.ts
index feef6d466ef4..130670192207 100644
--- a/packages/app/src/context/file/path.test.ts
+++ b/packages/app/src/context/file/path.test.ts
@@ -1,5 +1,15 @@
 import { describe, expect, test } from "bun:test"
-import { createPathHelpers, stripQueryAndHash, unquoteGitPath, encodeFilePath } from "./path"
+import {
+  createPathHelpers,
+  dedupeFilePaths,
+  filePathAncestorKeys,
+  filePathEqual,
+  filePathKey,
+  filePathName,
+  filePathParentKey,
+  isFileTab,
+  normalizeFilePath,
+} from "./path"
 
 describe("file path helpers", () => {
   test("normalizes file inputs against workspace root", () => {
@@ -8,8 +18,16 @@ describe("file path helpers", () => {
     expect(path.normalize("/repo/src/app.ts")).toBe("src/app.ts")
     expect(path.normalize("./src/app.ts")).toBe("src/app.ts")
     expect(path.normalizeDir("src/components///")).toBe("src/components")
-    expect(path.tab("src/app.ts")).toBe("file://src/app.ts")
+    expect(path.tab("src/app.ts")).toBe("tab:file:src/app.ts")
+    expect(isFileTab(path.tab("src/app.ts"))).toBe(true)
+    expect(isFileTab("file:///repo/src/app.ts")).toBe(false)
+    expect(path.normalizeTab("file://src/app.ts")).toBe("tab:file:src/app.ts")
+    expect(path.normalizeTab("tab:file:src/app.ts")).toBe("tab:file:src/app.ts")
+    expect(path.normalizeTab("file:///repo/src/app.ts")).toBe("file:///repo/src/app.ts")
+    expect(path.normalizeTab("review")).toBe("review")
+    expect(path.pathFromTab("tab:file:src/app.ts")).toBe("src/app.ts")
     expect(path.pathFromTab("file://src/app.ts")).toBe("src/app.ts")
+    expect(path.pathFromTab("file:///repo/src/app.ts")).toBeUndefined()
     expect(path.pathFromTab("other://src/app.ts")).toBeUndefined()
   })
 
@@ -21,340 +39,25 @@ describe("file path helpers", () => {
     expect(path.normalize("c:\\repo\\src\\app.ts")).toBe("src\\app.ts")
   })
 
-  test("keeps query/hash stripping behavior stable", () => {
-    expect(stripQueryAndHash("a/b.ts#L12?x=1")).toBe("a/b.ts")
-    expect(stripQueryAndHash("a/b.ts?x=1#L12")).toBe("a/b.ts")
-    expect(stripQueryAndHash("a/b.ts")).toBe("a/b.ts")
-  })
-
-  test("unquotes git escaped octal path strings", () => {
-    expect(unquoteGitPath('"a/\\303\\251.txt"')).toBe("a/\u00e9.txt")
-    expect(unquoteGitPath('"plain\\nname"')).toBe("plain\nname")
-    expect(unquoteGitPath("a/b/c.ts")).toBe("a/b/c.ts")
-  })
-})
-
-describe("encodeFilePath", () => {
-  describe("Linux/Unix paths", () => {
-    test("should handle Linux absolute path", () => {
-      const linuxPath = "/home/user/project/README.md"
-      const result = encodeFilePath(linuxPath)
-      const fileUrl = `file://${result}`
-
-      // Should create a valid URL
-      expect(() => new URL(fileUrl)).not.toThrow()
-      expect(result).toBe("/home/user/project/README.md")
-
-      const url = new URL(fileUrl)
-      expect(url.protocol).toBe("file:")
-      expect(url.pathname).toBe("/home/user/project/README.md")
-    })
-
-    test("should handle Linux path with special characters", () => {
-      const linuxPath = "/home/user/file#name with spaces.txt"
-      const result = encodeFilePath(linuxPath)
-      const fileUrl = `file://${result}`
-
-      expect(() => new URL(fileUrl)).not.toThrow()
-      expect(result).toBe("/home/user/file%23name%20with%20spaces.txt")
-    })
-
-    test("should handle Linux relative path", () => {
-      const relativePath = "src/components/App.tsx"
-      const result = encodeFilePath(relativePath)
-
-      expect(result).toBe("src/components/App.tsx")
-    })
-
-    test("should handle Linux root directory", () => {
-      const result = encodeFilePath("/")
-      expect(result).toBe("/")
-    })
-
-    test("should handle Linux path with all special chars", () => {
-      const path = "/path/to/file#with?special%chars&more.txt"
-      const result = encodeFilePath(path)
-      const fileUrl = `file://${result}`
-
-      expect(() => new URL(fileUrl)).not.toThrow()
-      expect(result).toContain("%23") // #
-      expect(result).toContain("%3F") // ?
-      expect(result).toContain("%25") // %
-      expect(result).toContain("%26") // &
-    })
-  })
-
-  describe("macOS paths", () => {
-    test("should handle macOS absolute path", () => {
-      const macPath = "/Users/kelvin/Projects/opencode/README.md"
-      const result = encodeFilePath(macPath)
-      const fileUrl = `file://${result}`
-
-      expect(() => new URL(fileUrl)).not.toThrow()
-      expect(result).toBe("/Users/kelvin/Projects/opencode/README.md")
-    })
-
-    test("should handle macOS path with spaces", () => {
-      const macPath = "/Users/kelvin/My Documents/file.txt"
-      const result = encodeFilePath(macPath)
-      const fileUrl = `file://${result}`
-
-      expect(() => new URL(fileUrl)).not.toThrow()
-      expect(result).toContain("My%20Documents")
-    })
-  })
-
-  describe("Windows paths", () => {
-    test("should handle Windows absolute path with backslashes", () => {
-      const windowsPath = "D:\\dev\\projects\\opencode\\README.bs.md"
-      const result = encodeFilePath(windowsPath)
-      const fileUrl = `file://${result}`
-
-      // Should create a valid, parseable URL
-      expect(() => new URL(fileUrl)).not.toThrow()
-
-      const url = new URL(fileUrl)
-      expect(url.protocol).toBe("file:")
-      expect(url.pathname).toContain("README.bs.md")
-      expect(result).toBe("/D:/dev/projects/opencode/README.bs.md")
-    })
-
-    test("should handle mixed separator path (Windows + Unix)", () => {
-      // This is what happens in build-request-parts.ts when concatenating paths
-      const mixedPath = "D:\\dev\\projects\\opencode/README.bs.md"
-      const result = encodeFilePath(mixedPath)
-      const fileUrl = `file://${result}`
-
-      expect(() => new URL(fileUrl)).not.toThrow()
-      expect(result).toBe("/D:/dev/projects/opencode/README.bs.md")
-    })
-
-    test("should handle Windows path with spaces", () => {
-      const windowsPath = "C:\\Program Files\\MyApp\\file with spaces.txt"
-      const result = encodeFilePath(windowsPath)
-      const fileUrl = `file://${result}`
-
-      expect(() => new URL(fileUrl)).not.toThrow()
-      expect(result).toContain("Program%20Files")
-      expect(result).toContain("file%20with%20spaces.txt")
-    })
-
-    test("should handle Windows path with special chars in filename", () => {
-      const windowsPath = "D:\\projects\\file#name with ?marks.txt"
-      const result = encodeFilePath(windowsPath)
-      const fileUrl = `file://${result}`
-
-      expect(() => new URL(fileUrl)).not.toThrow()
-      expect(result).toContain("file%23name%20with%20%3Fmarks.txt")
-    })
-
-    test("should handle Windows root directory", () => {
-      const windowsPath = "C:\\"
-      const result = encodeFilePath(windowsPath)
-      const fileUrl = `file://${result}`
-
-      expect(() => new URL(fileUrl)).not.toThrow()
-      expect(result).toBe("/C:/")
-    })
-
-    test("should handle Windows relative path with backslashes", () => {
-      const windowsPath = "src\\components\\App.tsx"
-      const result = encodeFilePath(windowsPath)
-
-      // Relative paths shouldn't get the leading slash
-      expect(result).toBe("src/components/App.tsx")
-    })
-
-    test("should NOT create invalid URL like the bug report", () => {
-      // This is the exact scenario from bug report by @alexyaroshuk
-      const windowsPath = "D:\\dev\\projects\\opencode\\README.bs.md"
-      const result = encodeFilePath(windowsPath)
-      const fileUrl = `file://${result}`
-
-      // The bug was creating: file://D%3A%5Cdev%5Cprojects%5Copencode/README.bs.md
-      expect(result).not.toContain("%5C") // Should not have encoded backslashes
-      expect(result).not.toBe("D%3A%5Cdev%5Cprojects%5Copencode/README.bs.md")
-
-      // Should be valid
-      expect(() => new URL(fileUrl)).not.toThrow()
-    })
+  test("renders display paths with native separators", () => {
+    const posix = createPathHelpers(() => "/repo")
+    expect(posix.display("tab:file:src/app.ts")).toBe("src/app.ts")
 
-    test("should handle lowercase drive letters", () => {
-      const windowsPath = "c:\\users\\test\\file.txt"
-      const result = encodeFilePath(windowsPath)
-      const fileUrl = `file://${result}`
-
-      expect(() => new URL(fileUrl)).not.toThrow()
-      expect(result).toBe("/c:/users/test/file.txt")
-    })
-  })
-
-  describe("Cross-platform compatibility", () => {
-    test("should preserve Unix paths unchanged (except encoding)", () => {
-      const unixPath = "/usr/local/bin/app"
-      const result = encodeFilePath(unixPath)
-      expect(result).toBe("/usr/local/bin/app")
-    })
-
-    test("should normalize Windows paths for cross-platform use", () => {
-      const windowsPath = "C:\\Users\\test\\file.txt"
-      const result = encodeFilePath(windowsPath)
-      // Should convert to forward slashes and add leading /
-      expect(result).not.toContain("\\")
-      expect(result).toMatch(/^\/[A-Za-z]:\//)
-    })
-
-    test("should handle relative paths the same on all platforms", () => {
-      const unixRelative = "src/app.ts"
-      const windowsRelative = "src\\app.ts"
-
-      const unixResult = encodeFilePath(unixRelative)
-      const windowsResult = encodeFilePath(windowsRelative)
-
-      // Both should normalize to forward slashes
-      expect(unixResult).toBe("src/app.ts")
-      expect(windowsResult).toBe("src/app.ts")
-    })
-  })
-
-  describe("Edge cases", () => {
-    test("should handle empty path", () => {
-      const result = encodeFilePath("")
-      expect(result).toBe("")
-    })
-
-    test("should handle path with multiple consecutive slashes", () => {
-      const result = encodeFilePath("//path//to///file.txt")
-      // Multiple slashes should be preserved (backend handles normalization)
-      expect(result).toBe("//path//to///file.txt")
-    })
-
-    test("should encode Unicode characters", () => {
-      const unicodePath = "/home/user/文档/README.md"
-      const result = encodeFilePath(unicodePath)
-      const fileUrl = `file://${result}`
-
-      expect(() => new URL(fileUrl)).not.toThrow()
-      // Unicode should be encoded
-      expect(result).toContain("%E6%96%87%E6%A1%A3")
-    })
-
-    test("should handle already normalized Windows path", () => {
-      // Path that's already been normalized (has / before drive letter)
-      const alreadyNormalized = "/D:/path/file.txt"
-      const result = encodeFilePath(alreadyNormalized)
-
-      // Should not add another leading slash
-      expect(result).toBe("/D:/path/file.txt")
-      expect(result).not.toContain("//D")
-    })
-
-    test("should handle just drive letter", () => {
-      const justDrive = "D:"
-      const result = encodeFilePath(justDrive)
-      const fileUrl = `file://${result}`
-
-      expect(result).toBe("/D:")
-      expect(() => new URL(fileUrl)).not.toThrow()
-    })
-
-    test("should handle Windows path with trailing backslash", () => {
-      const trailingBackslash = "C:\\Users\\test\\"
-      const result = encodeFilePath(trailingBackslash)
-      const fileUrl = `file://${result}`
-
-      expect(() => new URL(fileUrl)).not.toThrow()
-      expect(result).toBe("/C:/Users/test/")
-    })
-
-    test("should handle very long paths", () => {
-      const longPath = "C:\\Users\\test\\" + "verylongdirectoryname\\".repeat(20) + "file.txt"
-      const result = encodeFilePath(longPath)
-      const fileUrl = `file://${result}`
-
-      expect(() => new URL(fileUrl)).not.toThrow()
-      expect(result).not.toContain("\\")
-    })
-
-    test("should handle paths with dots", () => {
-      const pathWithDots = "C:\\Users\\..\\test\\.\\file.txt"
-      const result = encodeFilePath(pathWithDots)
-      const fileUrl = `file://${result}`
-
-      expect(() => new URL(fileUrl)).not.toThrow()
-      // Dots should be preserved (backend normalizes)
-      expect(result).toContain("..")
-      expect(result).toContain("/./")
-    })
-  })
-
-  describe("Regression tests for PR #12424", () => {
-    test("should handle file with # in name", () => {
-      const path = "/path/to/file#name.txt"
-      const result = encodeFilePath(path)
-      const fileUrl = `file://${result}`
-
-      expect(() => new URL(fileUrl)).not.toThrow()
-      expect(result).toBe("/path/to/file%23name.txt")
-    })
-
-    test("should handle file with ? in name", () => {
-      const path = "/path/to/file?name.txt"
-      const result = encodeFilePath(path)
-      const fileUrl = `file://${result}`
-
-      expect(() => new URL(fileUrl)).not.toThrow()
-      expect(result).toBe("/path/to/file%3Fname.txt")
-    })
-
-    test("should handle file with % in name", () => {
-      const path = "/path/to/file%name.txt"
-      const result = encodeFilePath(path)
-      const fileUrl = `file://${result}`
-
-      expect(() => new URL(fileUrl)).not.toThrow()
-      expect(result).toBe("/path/to/file%25name.txt")
-    })
+    const win = createPathHelpers(() => "C:\\repo")
+    expect(win.display("src/app.ts")).toBe("src\\app.ts")
+    expect(win.display("file://src/app.ts")).toBe("src\\app.ts")
+    expect(win.display("tab:file:src/app.ts")).toBe("src\\app.ts")
+    expect(win.display("C:/repo/src/app.ts")).toBe("src\\app.ts")
+    expect(win.display("src/app/")).toBe("src\\app\\")
   })
 
-  describe("Integration with file:// URL construction", () => {
-    test("should work with query parameters (Linux)", () => {
-      const path = "/home/user/file.txt"
-      const encoded = encodeFilePath(path)
-      const fileUrl = `file://${encoded}?start=10&end=20`
-
-      const url = new URL(fileUrl)
-      expect(url.searchParams.get("start")).toBe("10")
-      expect(url.searchParams.get("end")).toBe("20")
-      expect(url.pathname).toBe("/home/user/file.txt")
-    })
-
-    test("should work with query parameters (Windows)", () => {
-      const path = "C:\\Users\\test\\file.txt"
-      const encoded = encodeFilePath(path)
-      const fileUrl = `file://${encoded}?start=10&end=20`
-
-      const url = new URL(fileUrl)
-      expect(url.searchParams.get("start")).toBe("10")
-      expect(url.searchParams.get("end")).toBe("20")
-    })
-
-    test("should parse correctly in URL constructor (Linux)", () => {
-      const path = "/var/log/app.log"
-      const fileUrl = `file://${encodeFilePath(path)}`
-      const url = new URL(fileUrl)
-
-      expect(url.protocol).toBe("file:")
-      expect(url.pathname).toBe("/var/log/app.log")
-    })
-
-    test("should parse correctly in URL constructor (Windows)", () => {
-      const path = "D:\\logs\\app.log"
-      const fileUrl = `file://${encodeFilePath(path)}`
-      const url = new URL(fileUrl)
-
-      expect(url.protocol).toBe("file:")
-      expect(url.pathname).toContain("app.log")
-    })
+  test("normalizes app file keys across slash variants", () => {
+    expect(String(filePathKey("src\\app.ts"))).toBe("src/app.ts")
+    expect(normalizeFilePath("src\\app.ts")).toBe("src/app.ts")
+    expect(filePathEqual("src\\app.ts", "src/app.ts")).toBe(true)
+    expect(dedupeFilePaths(["src\\app.ts", "src/app.ts", "src/util.ts"])).toEqual(["src\\app.ts", "src/util.ts"])
+    expect(String(filePathParentKey(filePathKey("src/app.ts")))).toBe("src")
+    expect(filePathAncestorKeys(filePathKey("src/deep/app.ts")).map(String)).toEqual(["src", "src/deep"])
+    expect(filePathName(filePathKey("src/deep/app.ts"))).toBe("app.ts")
   })
 })
diff --git a/packages/app/src/context/file/path.ts b/packages/app/src/context/file/path.ts
index 53f072b6cb26..f7e5f2b523eb 100644
--- a/packages/app/src/context/file/path.ts
+++ b/packages/app/src/context/file/path.ts
@@ -1,124 +1,106 @@
-export function stripFileProtocol(input: string) {
-  if (!input.startsWith("file://")) return input
-  return input.slice("file://".length)
+import {
+  decodeFilePath,
+  getPathSeparator,
+  getPathRoot,
+  getWorkspaceRelativePath,
+  pathEqual,
+  pathKey,
+  stripFileProtocol,
+  stripQueryAndHash,
+  unquoteGitPath,
+  encodeFilePath,
+} from "@opencode-ai/util/path"
+
+export type PrettyPath = string
+export type WorkspacePath = PrettyPath
+export type ReviewPath = PrettyPath
+export type FilePath = PrettyPath
+export type FileUri = `file://${string}`
+
+export type WorkspaceKey = string & { _brand: "WorkspaceKey" }
+export type FilePathKey = string & { _brand: "FilePathKey" }
+type LegacyFileTabId = FileUri
+export const FILE_TAB_PREFIX = "tab:file:" as const
+export type FileTabId = `${typeof FILE_TAB_PREFIX}${string}`
+export type SessionTabId = "context" | "review" | FileTabId
+export type StoredSessionTabId = SessionTabId | FileUri
+export const ROOT_FILE_PATH = "" as FilePath
+export const ROOT_FILE_PATH_KEY = "" as FilePathKey
+
+export const workspacePathKey = (input: WorkspacePath) => pathKey(input) as WorkspaceKey
+
+export const reviewPathKey = (input: ReviewPath) => pathKey(input)
+
+export const filePathKey = (input: FilePath) => pathKey(input) as FilePathKey
+
+const legacyTabPath = (input: string) => {
+  if (!input.startsWith("file://")) return
+  const path = decodeFilePath(stripQueryAndHash(stripFileProtocol(input)))
+  if (getPathRoot(path)) return
+  if (path.startsWith("/") || path.startsWith("\\")) return
+  return path
 }
 
-export function stripQueryAndHash(input: string) {
-  const hashIndex = input.indexOf("#")
-  const queryIndex = input.indexOf("?")
+const stripTab = (input: string) => (input.startsWith(FILE_TAB_PREFIX) ? input.slice(FILE_TAB_PREFIX.length) : input)
 
-  if (hashIndex !== -1 && queryIndex !== -1) {
-    return input.slice(0, Math.min(hashIndex, queryIndex))
-  }
-
-  if (hashIndex !== -1) return input.slice(0, hashIndex)
-  if (queryIndex !== -1) return input.slice(0, queryIndex)
-  return input
+export const isFileTab = (input: string): input is FileTabId | LegacyFileTabId => {
+  if (input.startsWith(FILE_TAB_PREFIX)) return true
+  return legacyTabPath(input) !== undefined
 }
 
-export function unquoteGitPath(input: string) {
-  if (!input.startsWith('"')) return input
-  if (!input.endsWith('"')) return input
-  const body = input.slice(1, -1)
-  const bytes: number[] = []
-
-  for (let i = 0; i < body.length; i++) {
-    const char = body[i]!
-    if (char !== "\\") {
-      bytes.push(char.charCodeAt(0))
-      continue
-    }
+export const filePathEqual = (a: FilePath | undefined, b: FilePath | undefined) => pathEqual(a, b)
 
-    const next = body[i + 1]
-    if (!next) {
-      bytes.push("\\".charCodeAt(0))
-      continue
-    }
+export const filePathFromKey = (input: FilePathKey) => input as FilePath
 
-    if (next >= "0" && next <= "7") {
-      const chunk = body.slice(i + 1, i + 4)
-      const match = chunk.match(/^[0-7]{1,3}/)
-      if (!match) {
-        bytes.push(next.charCodeAt(0))
-        i++
-        continue
-      }
-      bytes.push(parseInt(match[0], 8))
-      i += match[0].length
-      continue
-    }
+export const normalizeFilePath = (input: string) => filePathFromKey(pathKey(input) as FilePathKey)
 
-    const escaped =
-      next === "n"
-        ? "\n"
-        : next === "r"
-          ? "\r"
-          : next === "t"
-            ? "\t"
-            : next === "b"
-              ? "\b"
-              : next === "f"
-                ? "\f"
-                : next === "v"
-                  ? "\v"
-                  : next === "\\" || next === '"'
-                    ? next
-                    : undefined
-
-    bytes.push((escaped ?? next).charCodeAt(0))
-    i++
-  }
+export function filePathParentKey(input: FilePathKey) {
+  const split = input.lastIndexOf("/")
+  if (split === -1) return ROOT_FILE_PATH_KEY
+  return input.slice(0, split) as FilePathKey
+}
 
-  return new TextDecoder().decode(new Uint8Array(bytes))
+export function filePathName(input: FilePathKey) {
+  const split = input.lastIndexOf("/")
+  if (split === -1) return input
+  return input.slice(split + 1)
 }
 
-export function decodeFilePath(input: string) {
-  try {
-    return decodeURIComponent(input)
-  } catch {
-    return input
+export function filePathAncestorKeys(input: FilePathKey) {
+  const out: FilePathKey[] = []
+
+  for (let key = filePathParentKey(input); key !== ROOT_FILE_PATH_KEY; key = filePathParentKey(key)) {
+    out.unshift(key)
   }
+
+  return out
 }
 
-export function encodeFilePath(filepath: string): string {
-  // Normalize Windows paths: convert backslashes to forward slashes
-  let normalized = filepath.replace(/\\/g, "/")
+export function filePathDescendsFrom(input: FilePathKey, parent: FilePathKey) {
+  if (parent === ROOT_FILE_PATH_KEY) return input !== ROOT_FILE_PATH_KEY
+  return input.startsWith(parent + "/")
+}
 
-  // Handle Windows absolute paths (D:/path -> /D:/path for proper file:// URLs)
-  if (/^[A-Za-z]:/.test(normalized)) {
-    normalized = "/" + normalized
+export function dedupeFilePaths(paths: readonly FilePath[]) {
+  const seen = new Set<FilePathKey>()
+  const out: FilePath[] = []
+
+  for (const path of paths) {
+    const key = filePathKey(path)
+    if (seen.has(key)) continue
+    seen.add(key)
+    out.push(path)
   }
 
-  // Encode each path segment (preserving forward slashes as path separators)
-  // Keep the colon in Windows drive letters (`/C:/...`) so downstream file URL parsers
-  // can reliably detect drives.
-  return normalized
-    .split("/")
-    .map((segment, index) => {
-      if (index === 1 && /^[A-Za-z]:$/.test(segment)) return segment
-      return encodeURIComponent(segment)
-    })
-    .join("/")
+  return out
 }
 
-export function createPathHelpers(scope: () => string) {
-  const normalize = (input: string) => {
+export function createPathHelpers(scope: () => WorkspacePath) {
+  const normalize = (input: string): FilePath => {
     const root = scope()
 
-    let path = unquoteGitPath(decodeFilePath(stripQueryAndHash(stripFileProtocol(input))))
-
-    // Separator-agnostic prefix stripping for Cygwin/native Windows compatibility
-    // Only case-insensitive on Windows (drive letter or UNC paths)
-    const windows = /^[A-Za-z]:/.test(root) || root.startsWith("\\\\")
-    const canonRoot = windows ? root.replace(/\\/g, "/").toLowerCase() : root.replace(/\\/g, "/")
-    const canonPath = windows ? path.replace(/\\/g, "/").toLowerCase() : path.replace(/\\/g, "/")
-    if (
-      canonPath.startsWith(canonRoot) &&
-      (canonRoot.endsWith("/") || canonPath === canonRoot || canonPath[canonRoot.length] === "/")
-    ) {
-      // Slice from original path to preserve native separators
-      path = path.slice(root.length)
-    }
+    let path = unquoteGitPath(decodeFilePath(stripQueryAndHash(stripFileProtocol(stripTab(input)))))
+    path = getWorkspaceRelativePath(path, root)
 
     if (path.startsWith("./") || path.startsWith(".\\")) {
       path = path.slice(2)
@@ -130,21 +112,41 @@ export function createPathHelpers(scope: () => string) {
     return path
   }
 
-  const tab = (input: string) => {
+  const display = (input: string): FilePath => {
+    const path = normalize(input)
+    if (getPathSeparator(scope()) === "/") return path
+    return path.replace(/\//g, "\\")
+  }
+
+  const tab = (input: FilePath): FileTabId => {
     const path = normalize(input)
-    return `file://${encodeFilePath(path)}`
+    return `${FILE_TAB_PREFIX}${encodeFilePath(path)}`
+  }
+
+  const key = (input: string) => filePathKey(normalize(input))
+
+  const dirKey = (input: string) => filePathKey(normalizeDir(input))
+
+  const normalizeTab = (input: string) => {
+    const path = pathFromTab(input)
+    if (!path) return input
+    return tab(path)
   }
 
   const pathFromTab = (tabValue: string) => {
-    if (!tabValue.startsWith("file://")) return
+    if (!isFileTab(tabValue)) return
     return normalize(tabValue)
   }
 
-  const normalizeDir = (input: string) => normalize(input).replace(/\/+$/, "")
+  const normalizeDir = (input: string): FilePath => normalize(input).replace(/[\\/]+$/, "")
 
   return {
     normalize,
+    display,
+    key,
+    dirKey,
     tab,
+    normalizeTab,
     pathFromTab,
     normalizeDir,
   }
diff --git a/packages/app/src/context/file/tree-store.test.ts b/packages/app/src/context/file/tree-store.test.ts
new file mode 100644
index 000000000000..67fba1bc1e51
--- /dev/null
+++ b/packages/app/src/context/file/tree-store.test.ts
@@ -0,0 +1,41 @@
+import { describe, expect, test } from "bun:test"
+import { filePathKey } from "./path"
+import { createFileTreeStore } from "./tree-store"
+
+describe("file tree store path handling", () => {
+  test("normalizes node and directory keys across slash variants", async () => {
+    const normalize = (input: string) => input.replace(/\\/g, "/").replace(/[\\/]+$/, "")
+    const tree = createFileTreeStore({
+      scope: () => "/repo",
+      normalize,
+      normalizeDir: normalize,
+      list: async (input) => {
+        if (!input) {
+          return [
+            { name: "src", path: "src\\core", absolute: "src\\core", type: "directory", ignored: false },
+            { name: "app.ts", path: "src\\app.ts", absolute: "src\\app.ts", type: "file", ignored: false },
+          ]
+        }
+
+        return [{ name: "util.ts", path: "src/core\\util.ts", absolute: "src/core\\util.ts", type: "file", ignored: false }]
+      },
+      onError() {},
+    })
+
+    await tree.listDir("")
+
+    expect(tree.children("").map((node) => node.path)).toEqual(["src/core", "src/app.ts"])
+    expect(tree.node("src\\app.ts")?.path).toBe("src/app.ts")
+    expect(tree.dirPathByKey(filePathKey(""))).toBe("")
+
+    tree.expandDir("src\\core")
+    expect(tree.dirState("src/core")?.expanded).toBe(true)
+
+    await tree.listDir("src/core")
+    expect(tree.children("src\\core").map((node) => node.path)).toEqual(["src/core/util.ts"])
+    expect(tree.dirPathByKey(filePathKey("src\\core"))).toBe("src/core")
+
+    tree.collapseDir("src/core")
+    expect(tree.dirState("src\\core")?.expanded).toBe(false)
+  })
+})
diff --git a/packages/app/src/context/file/tree-store.ts b/packages/app/src/context/file/tree-store.ts
index a86051d286ec..1aa4b3f66615 100644
--- a/packages/app/src/context/file/tree-store.ts
+++ b/packages/app/src/context/file/tree-store.ts
@@ -1,47 +1,84 @@
 import { createStore, produce, reconcile } from "solid-js/store"
 import type { FileNode } from "@opencode-ai/sdk/v2"
+import {
+  ROOT_FILE_PATH,
+  ROOT_FILE_PATH_KEY,
+  filePathDescendsFrom,
+  filePathKey,
+  type FilePath,
+  type FilePathKey,
+  type WorkspacePath,
+} from "./path"
+
+type TreeNode = FileNode & { path: FilePath }
 
 type DirectoryState = {
+  path: FilePath
   expanded: boolean
   loaded?: boolean
   loading?: boolean
   error?: string
-  children?: string[]
+  children?: FilePathKey[]
 }
 
 type TreeStoreOptions = {
-  scope: () => string
-  normalizeDir: (input: string) => string
-  list: (input: string) => Promise<FileNode[]>
+  scope: () => WorkspacePath
+  normalize: (input: string) => FilePath
+  normalizeDir: (input: string) => FilePath
+  list: (input: FilePath) => Promise<FileNode[]>
   onError: (message: string) => void
 }
 
 export function createFileTreeStore(options: TreeStoreOptions) {
+  const dirKey = (path: FilePath) => filePathKey(path)
+  const nodeKey = (path: FilePath) => filePathKey(path)
+  const nodePath = (node: FileNode) => (node.type === "directory" ? options.normalizeDir(node.path) : options.normalize(node.path))
   const [tree, setTree] = createStore<{
-    node: Record<string, FileNode>
-    dir: Record<string, DirectoryState>
+    node: Record<FilePathKey, TreeNode>
+    dir: Record<FilePathKey, DirectoryState>
   }>({
     node: {},
-    dir: { "": { expanded: true } },
+    dir: { [ROOT_FILE_PATH_KEY]: { path: ROOT_FILE_PATH, expanded: true } },
   })
 
-  const inflight = new Map<string, Promise<void>>()
+  const inflight = new Map<FilePathKey, Promise<void>>()
+  const normalizeNode = (node: FileNode): TreeNode => ({
+    ...node,
+    path: nodePath(node),
+  })
+
+  const dropDirs = (dirs: readonly FilePathKey[]) => {
+    if (dirs.length === 0) return
+
+    setTree(
+      "dir",
+      produce((draft) => {
+        for (const key of Object.keys(draft) as FilePathKey[]) {
+          if (key === ROOT_FILE_PATH_KEY) continue
+          if (!dirs.some((dir) => key === dir || filePathDescendsFrom(key, dir))) continue
+          delete draft[key]
+        }
+      }),
+    )
+  }
 
   const reset = () => {
     inflight.clear()
     setTree("node", reconcile({}))
     setTree("dir", reconcile({}))
-    setTree("dir", "", { expanded: true })
+    setTree("dir", ROOT_FILE_PATH_KEY, { path: ROOT_FILE_PATH, expanded: true })
   }
 
-  const ensureDir = (path: string) => {
-    if (tree.dir[path]) return
-    setTree("dir", path, { expanded: false })
+  const ensureDir = (path: FilePath) => {
+    const dir = dirKey(path)
+    if (tree.dir[dir]) return
+    setTree("dir", dir, { path, expanded: false })
   }
 
   const listDir = (input: string, opts?: { force?: boolean }) => {
-    const dir = options.normalizeDir(input)
-    ensureDir(dir)
+    const path = options.normalizeDir(input)
+    const dir = dirKey(path)
+    ensureDir(path)
 
     const current = tree.dir[dir]
     if (!opts?.force && current?.loaded) return Promise.resolve()
@@ -61,18 +98,18 @@ export function createFileTreeStore(options: TreeStoreOptions) {
     const directory = options.scope()
 
     const promise = options
-      .list(dir)
-      .then((nodes) => {
+      .list(path)
+      .then((items) => {
         if (options.scope() !== directory) return
+        const nodes = items.map(normalizeNode)
         const prevChildren = tree.dir[dir]?.children ?? []
-        const nextChildren = nodes.map((node) => node.path)
+        const nextChildren = nodes.map((node) => nodeKey(node.path))
         const nextSet = new Set(nextChildren)
+        const removedDirs: FilePathKey[] = []
 
         setTree(
           "node",
           produce((draft) => {
-            const removedDirs: string[] = []
-
             for (const child of prevChildren) {
               if (nextSet.has(child)) continue
               const existing = draft[child]
@@ -80,27 +117,24 @@ export function createFileTreeStore(options: TreeStoreOptions) {
               delete draft[child]
             }
 
-            if (removedDirs.length > 0) {
-              const keys = Object.keys(draft)
-              for (const key of keys) {
-                for (const removed of removedDirs) {
-                  if (!key.startsWith(removed + "/")) continue
-                  delete draft[key]
-                  break
-                }
-              }
+            for (const key of Object.keys(draft) as FilePathKey[]) {
+              if (!removedDirs.some((dir) => filePathDescendsFrom(key, dir))) continue
+              delete draft[key]
             }
 
             for (const node of nodes) {
-              draft[node.path] = node
+              draft[nodeKey(node.path)] = node
             }
           }),
         )
 
+        dropDirs(removedDirs)
+
         setTree(
           "dir",
           dir,
           produce((draft) => {
+            draft.path = path
             draft.loaded = true
             draft.loading = false
             draft.children = nextChildren
@@ -128,33 +162,32 @@ export function createFileTreeStore(options: TreeStoreOptions) {
   }
 
   const expandDir = (input: string) => {
-    const dir = options.normalizeDir(input)
-    ensureDir(dir)
+    const path = options.normalizeDir(input)
+    const dir = dirKey(path)
+    ensureDir(path)
     setTree("dir", dir, "expanded", true)
-    void listDir(dir)
+    void listDir(path)
   }
 
   const collapseDir = (input: string) => {
-    const dir = options.normalizeDir(input)
-    ensureDir(dir)
+    const path = options.normalizeDir(input)
+    const dir = dirKey(path)
+    ensureDir(path)
     setTree("dir", dir, "expanded", false)
   }
 
   const dirState = (input: string) => {
-    const dir = options.normalizeDir(input)
+    const dir = dirKey(options.normalizeDir(input))
     return tree.dir[dir]
   }
 
   const children = (input: string) => {
-    const dir = options.normalizeDir(input)
-    const ids = tree.dir[dir]?.children
-    if (!ids) return []
-    const out: FileNode[] = []
-    for (const id of ids) {
+    const dir = dirKey(options.normalizeDir(input))
+    return (tree.dir[dir]?.children ?? []).flatMap((id) => {
       const node = tree.node[id]
-      if (node) out.push(node)
-    }
-    return out
+      if (!node) return []
+      return [node]
+    })
   }
 
   return {
@@ -163,8 +196,15 @@ export function createFileTreeStore(options: TreeStoreOptions) {
     collapseDir,
     dirState,
     children,
-    node: (path: string) => tree.node[path],
-    isLoaded: (path: string) => Boolean(tree.dir[path]?.loaded),
+    node: (path: string) => tree.node[nodeKey(options.normalize(path))],
+    nodeByKey: (key: FilePathKey) => tree.node[key],
+    dirByKey: (key: FilePathKey) => tree.dir[key],
+    dirPathByKey: (key: FilePathKey) => {
+      const dir = tree.dir[key]
+      if (!dir?.loaded) return
+      return dir.path
+    },
+    isLoaded: (path: string) => Boolean(tree.dir[dirKey(options.normalizeDir(path))]?.loaded),
     reset,
   }
 }
diff --git a/packages/app/src/context/file/types.ts b/packages/app/src/context/file/types.ts
index 7ce8a37c25e6..e9087032c0b9 100644
--- a/packages/app/src/context/file/types.ts
+++ b/packages/app/src/context/file/types.ts
@@ -1,4 +1,5 @@
 import type { FileContent } from "@opencode-ai/sdk/v2"
+import type { FilePath } from "./path"
 
 export type FileSelection = {
   startLine: number
@@ -21,7 +22,7 @@ export type FileViewState = {
 }
 
 export type FileState = {
-  path: string
+  path: FilePath
   name: string
   loaded?: boolean
   loading?: boolean
diff --git a/packages/app/src/context/file/view-cache.test.ts b/packages/app/src/context/file/view-cache.test.ts
new file mode 100644
index 000000000000..0c31fba020cb
--- /dev/null
+++ b/packages/app/src/context/file/view-cache.test.ts
@@ -0,0 +1,22 @@
+import { describe, expect, test } from "bun:test"
+import { migrateFileViewState } from "./view-cache"
+
+describe("migrateFileViewState", () => {
+  test("normalizes persisted file-view payload keys once", () => {
+    expect(
+      migrateFileViewState("C:\\repo", {
+        file: {
+          "src\\a.ts": { scrollTop: 10 },
+          "file://C:/repo/src/a.ts": { scrollLeft: 20 },
+          "C:/repo/src/b.ts": { selectedLines: { start: 4, end: 2, side: "additions" } },
+          invalid: null,
+        },
+      }),
+    ).toEqual({
+      file: {
+        "src/a.ts": { scrollTop: 10, scrollLeft: 20 },
+        "src/b.ts": { selectedLines: { start: 4, end: 2, side: "additions" } },
+      },
+    })
+  })
+})
diff --git a/packages/app/src/context/file/view-cache.ts b/packages/app/src/context/file/view-cache.ts
index 4c060174ab8c..fdcf19ab38f8 100644
--- a/packages/app/src/context/file/view-cache.ts
+++ b/packages/app/src/context/file/view-cache.ts
@@ -2,11 +2,18 @@ import { createEffect, createRoot } from "solid-js"
 import { createStore, produce } from "solid-js/store"
 import { Persist, persisted } from "@/utils/persist"
 import { createScopedCache } from "@/utils/scoped-cache"
+import { sessionScopeKey, sessionScopeParts } from "@/utils/session-key"
+import { createPathHelpers, filePathKey, type FilePath, type FilePathKey, type WorkspacePath } from "./path"
 import type { FileViewState, SelectedLineRange } from "./types"
 
-const WORKSPACE_KEY = "__workspace__"
 const MAX_FILE_VIEW_SESSIONS = 20
 const MAX_VIEW_FILES = 500
+const fileKey = (path: FilePath) => filePathKey(path)
+
+const record = (value: unknown): value is Record<string, unknown> =>
+  typeof value === "object" && value !== null && !Array.isArray(value)
+
+const num = (value: unknown) => (typeof value === "number" && Number.isFinite(value) ? value : undefined)
 
 function normalizeSelectedLines(range: SelectedLineRange): SelectedLineRange {
   if (range.start <= range.end) return { ...range }
@@ -33,13 +40,59 @@ function equalSelectedLines(a: SelectedLineRange | null | undefined, b: Selected
   )
 }
 
-function createViewSession(dir: string, id: string | undefined) {
-  const legacyViewKey = `${dir}/file${id ? "/" + id : ""}.v1`
+function state(value: unknown): FileViewState | undefined {
+  if (!record(value)) return
+  return {
+    ...(num(value.scrollTop) !== undefined ? { scrollTop: num(value.scrollTop) } : {}),
+    ...(num(value.scrollLeft) !== undefined ? { scrollLeft: num(value.scrollLeft) } : {}),
+    ...(value.selectedLines === null ? { selectedLines: null } : record(value.selectedLines) ? { selectedLines: value.selectedLines as SelectedLineRange } : {}),
+  }
+}
+
+function merge(prev: FileViewState, next: FileViewState) {
+  return {
+    ...prev,
+    ...next,
+    ...(next.selectedLines !== undefined ? { selectedLines: next.selectedLines } : {}),
+  }
+}
 
+export function migrateFileViewState(dir: WorkspacePath, value: unknown) {
+  if (!record(value)) return value
+  if (!record(value.file)) return value
+
+  const path = createPathHelpers(() => dir)
+  let changed = false
+  const file: Record<FilePathKey, FileViewState> = {}
+
+  for (const [name, item] of Object.entries(value.file)) {
+    const next = state(item)
+    if (!next) {
+      changed = true
+      continue
+    }
+
+    const normalized = path.normalize(name)
+    const key = fileKey(normalized)
+    if (key !== name || file[key]) changed = true
+    file[key] = file[key] ? merge(file[key], next) : next
+  }
+
+  if (!changed) return value
+  return {
+    ...value,
+    file,
+  }
+}
+
+function createViewSession(dir: WorkspacePath, id: string | undefined) {
   const [view, setView, _, ready] = persisted(
-    Persist.scoped(dir, id, "file-view", [legacyViewKey]),
+    {
+      ...Persist.scoped(dir, id, "file-view", Persist.legacyScoped(dir, id, "file", "v1")),
+      migrate: (value) => migrateFileViewState(dir, value),
+    },
     createStore<{
-      file: Record<string, FileViewState>
+      file: Record<FilePathKey, FileViewState>
     }>({
       file: {},
     }),
@@ -47,7 +100,7 @@ function createViewSession(dir: string, id: string | undefined) {
 
   const meta = { pruned: false }
 
-  const pruneView = (keep?: string) => {
+  const pruneView = (keep?: FilePathKey) => {
     const keys = Object.keys(view.file)
     if (keys.length <= MAX_VIEW_FILES) return
 
@@ -56,7 +109,7 @@ function createViewSession(dir: string, id: string | undefined) {
 
     setView(
       produce((draft) => {
-        for (const key of drop) {
+        for (const key of drop as FilePathKey[]) {
           delete draft.file[key]
         }
       }),
@@ -70,42 +123,45 @@ function createViewSession(dir: string, id: string | undefined) {
     pruneView()
   })
 
-  const scrollTop = (path: string) => view.file[path]?.scrollTop
-  const scrollLeft = (path: string) => view.file[path]?.scrollLeft
-  const selectedLines = (path: string) => view.file[path]?.selectedLines
+  const scrollTop = (path: FilePath) => view.file[fileKey(path)]?.scrollTop
+  const scrollLeft = (path: FilePath) => view.file[fileKey(path)]?.scrollLeft
+  const selectedLines = (path: FilePath) => view.file[fileKey(path)]?.selectedLines
 
-  const setScrollTop = (path: string, top: number) => {
+  const setScrollTop = (path: FilePath, top: number) => {
+    const key = fileKey(path)
     setView(
       produce((draft) => {
-        const file = draft.file[path] ?? (draft.file[path] = {})
+        const file = draft.file[key] ?? (draft.file[key] = {})
         if (file.scrollTop === top) return
         file.scrollTop = top
       }),
     )
-    pruneView(path)
+    pruneView(key)
   }
 
-  const setScrollLeft = (path: string, left: number) => {
+  const setScrollLeft = (path: FilePath, left: number) => {
+    const key = fileKey(path)
     setView(
       produce((draft) => {
-        const file = draft.file[path] ?? (draft.file[path] = {})
+        const file = draft.file[key] ?? (draft.file[key] = {})
         if (file.scrollLeft === left) return
         file.scrollLeft = left
       }),
     )
-    pruneView(path)
+    pruneView(key)
   }
 
-  const setSelectedLines = (path: string, range: SelectedLineRange | null) => {
+  const setSelectedLines = (path: FilePath, range: SelectedLineRange | null) => {
+    const key = fileKey(path)
     const next = range ? normalizeSelectedLines(range) : null
     setView(
       produce((draft) => {
-        const file = draft.file[path] ?? (draft.file[path] = {})
+        const file = draft.file[key] ?? (draft.file[key] = {})
         if (equalSelectedLines(file.selectedLines, next)) return
         file.selectedLines = next
       }),
     )
-    pruneView(path)
+    pruneView(key)
   }
 
   return {
@@ -122,11 +178,9 @@ function createViewSession(dir: string, id: string | undefined) {
 export function createFileViewCache() {
   const cache = createScopedCache(
     (key) => {
-      const split = key.lastIndexOf("\n")
-      const dir = split >= 0 ? key.slice(0, split) : key
-      const id = split >= 0 ? key.slice(split + 1) : WORKSPACE_KEY
+      const scope = sessionScopeParts(key)
       return createRoot((dispose) => ({
-        value: createViewSession(dir, id === WORKSPACE_KEY ? undefined : id),
+        value: createViewSession(scope.dir, scope.id),
         dispose,
       }))
     },
@@ -137,8 +191,8 @@ export function createFileViewCache() {
   )
 
   return {
-    load: (dir: string, id: string | undefined) => {
-      const key = `${dir}\n${id ?? WORKSPACE_KEY}`
+    load: (dir: WorkspacePath, id: string | undefined) => {
+      const key = sessionScopeKey(dir, id)
       return cache.get(key).value
     },
     clear: () => cache.clear(),
diff --git a/packages/app/src/context/file/watcher.test.ts b/packages/app/src/context/file/watcher.test.ts
index 9536b52536b6..aaf5dac2ba74 100644
--- a/packages/app/src/context/file/watcher.test.ts
+++ b/packages/app/src/context/file/watcher.test.ts
@@ -1,4 +1,5 @@
 import { describe, expect, test } from "bun:test"
+import { filePathKey } from "./path"
 import { invalidateFromWatcher } from "./watcher"
 
 describe("file watcher invalidation", () => {
@@ -15,10 +16,34 @@ describe("file watcher invalidation", () => {
       },
       {
         normalize: (input) => input,
-        hasFile: (path) => path === "src/new.ts",
+        file: (key) => (key === filePathKey("src/new.ts") ? "src/new.ts" : undefined),
+        dir: (key) => (key === filePathKey("src") ? "src" : undefined),
+        loadFile: (path) => loads.push(path),
+        refreshDir: (path) => refresh.push(path),
+      },
+    )
+
+    expect(loads).toEqual(["src/new.ts"])
+    expect(refresh).toEqual(["src"])
+  })
+
+  test("matches loaded files and parents across slash variants", () => {
+    const loads: string[] = []
+    const refresh: string[] = []
+
+    invalidateFromWatcher(
+      {
+        type: "file.watcher.updated",
+        properties: {
+          file: "src\\new.ts",
+          event: "add",
+        },
+      },
+      {
+        normalize: (input) => input,
+        file: (key) => (key === filePathKey("src/new.ts") ? "src/new.ts" : undefined),
+        dir: (key) => (key === filePathKey("src") ? "src" : undefined),
         loadFile: (path) => loads.push(path),
-        node: () => undefined,
-        isDirLoaded: (path) => path === "src",
         refreshDir: (path) => refresh.push(path),
       },
     )
@@ -40,17 +65,10 @@ describe("file watcher invalidation", () => {
       },
       {
         normalize: (input) => input,
-        hasFile: () => false,
-        isOpen: (path) => path === "src/open.ts",
+        file: () => undefined,
+        open: (key) => (key === filePathKey("src/open.ts") ? "src/open.ts" : undefined),
+        dir: () => undefined,
         loadFile: (path) => loads.push(path),
-        node: () => ({
-          path: "src/open.ts",
-          type: "file",
-          name: "open.ts",
-          absolute: "/repo/src/open.ts",
-          ignored: false,
-        }),
-        isDirLoaded: () => false,
         refreshDir: () => {},
       },
     )
@@ -71,10 +89,9 @@ describe("file watcher invalidation", () => {
       },
       {
         normalize: (input) => input,
-        hasFile: () => false,
+        file: () => undefined,
+        dir: (key) => (key === filePathKey("src") ? "src" : undefined),
         loadFile: () => {},
-        node: () => ({ path: "src", type: "directory", name: "src", absolute: "/repo/src", ignored: false }),
-        isDirLoaded: (path) => path === "src",
         refreshDir: (path) => refresh.push(path),
       },
     )
@@ -89,16 +106,9 @@ describe("file watcher invalidation", () => {
       },
       {
         normalize: (input) => input,
-        hasFile: () => false,
+        file: () => undefined,
+        dir: () => undefined,
         loadFile: () => {},
-        node: () => ({
-          path: "src/file.ts",
-          type: "file",
-          name: "file.ts",
-          absolute: "/repo/src/file.ts",
-          ignored: false,
-        }),
-        isDirLoaded: () => true,
         refreshDir: (path) => refresh.push(path),
       },
     )
@@ -106,6 +116,29 @@ describe("file watcher invalidation", () => {
     expect(refresh).toEqual(["src"])
   })
 
+  test("refreshes changed directories across slash variants", () => {
+    const refresh: string[] = []
+
+    invalidateFromWatcher(
+      {
+        type: "file.watcher.updated",
+        properties: {
+          file: "src\\nested",
+          event: "change",
+        },
+      },
+      {
+        normalize: (input) => input,
+        file: () => undefined,
+        dir: (key) => (key === filePathKey("src/nested") ? "src/nested" : undefined),
+        loadFile: () => {},
+        refreshDir: (path) => refresh.push(path),
+      },
+    )
+
+    expect(refresh).toEqual(["src/nested"])
+  })
+
   test("ignores invalid or git watcher updates", () => {
     const refresh: string[] = []
 
@@ -119,12 +152,30 @@ describe("file watcher invalidation", () => {
       },
       {
         normalize: (input) => input,
-        hasFile: () => true,
+        file: () => "src/a.ts",
+        dir: () => "src",
+        loadFile: () => {
+          throw new Error("should not load")
+        },
+        refreshDir: (path) => refresh.push(path),
+      },
+    )
+
+    invalidateFromWatcher(
+      {
+        type: "file.watcher.updated",
+        properties: {
+          file: ".git\\index.lock",
+          event: "change",
+        },
+      },
+      {
+        normalize: (input) => input,
+        file: () => "src/a.ts",
+        dir: () => "src",
         loadFile: () => {
           throw new Error("should not load")
         },
-        node: () => undefined,
-        isDirLoaded: () => true,
         refreshDir: (path) => refresh.push(path),
       },
     )
@@ -136,10 +187,9 @@ describe("file watcher invalidation", () => {
       },
       {
         normalize: (input) => input,
-        hasFile: () => false,
+        file: () => undefined,
+        dir: () => "src",
         loadFile: () => {},
-        node: () => undefined,
-        isDirLoaded: () => true,
         refreshDir: (path) => refresh.push(path),
       },
     )
diff --git a/packages/app/src/context/file/watcher.ts b/packages/app/src/context/file/watcher.ts
index fbf71992791a..6352b886173f 100644
--- a/packages/app/src/context/file/watcher.ts
+++ b/packages/app/src/context/file/watcher.ts
@@ -1,4 +1,4 @@
-import type { FileNode } from "@opencode-ai/sdk/v2"
+import { filePathKey, filePathParentKey, type FilePath, type FilePathKey } from "./path"
 
 type WatcherEvent = {
   type: string
@@ -6,13 +6,12 @@ type WatcherEvent = {
 }
 
 type WatcherOps = {
-  normalize: (input: string) => string
-  hasFile: (path: string) => boolean
-  isOpen?: (path: string) => boolean
-  loadFile: (path: string) => void
-  node: (path: string) => FileNode | undefined
-  isDirLoaded: (path: string) => boolean
-  refreshDir: (path: string) => void
+  normalize: (input: string) => FilePath
+  file: (key: FilePathKey) => FilePath | undefined
+  open?: (key: FilePathKey) => FilePath | undefined
+  dir: (key: FilePathKey) => FilePath | undefined
+  loadFile: (path: FilePath) => void
+  refreshDir: (path: FilePath) => void
 }
 
 export function invalidateFromWatcher(event: WatcherEvent, ops: WatcherOps) {
@@ -25,29 +24,21 @@ export function invalidateFromWatcher(event: WatcherEvent, ops: WatcherOps) {
   if (!kind) return
 
   const path = ops.normalize(rawPath)
-  if (!path) return
-  if (path.startsWith(".git/")) return
+  const key = filePathKey(path)
+  if (key.startsWith(".git/")) return
 
-  if (ops.hasFile(path) || ops.isOpen?.(path)) {
-    ops.loadFile(path)
-  }
+  const file = ops.file(key) ?? ops.open?.(key)
+  if (file) ops.loadFile(file)
 
   if (kind === "change") {
-    const dir = (() => {
-      if (path === "") return ""
-      const node = ops.node(path)
-      if (node?.type !== "directory") return
-      return path
-    })()
-    if (dir === undefined) return
-    if (!ops.isDirLoaded(dir)) return
+    const dir = ops.dir(key)
+    if (!dir) return
     ops.refreshDir(dir)
     return
   }
   if (kind !== "add" && kind !== "unlink") return
 
-  const parent = path.split("/").slice(0, -1).join("/")
-  if (!ops.isDirLoaded(parent)) return
-
+  const parent = ops.dir(filePathParentKey(key))
+  if (!parent) return
   ops.refreshDir(parent)
 }
diff --git a/packages/app/src/context/global-sdk.tsx b/packages/app/src/context/global-sdk.tsx
index 60e9fd6d542f..01119c9cb684 100644
--- a/packages/app/src/context/global-sdk.tsx
+++ b/packages/app/src/context/global-sdk.tsx
@@ -3,6 +3,7 @@ import { createSimpleContext } from "@opencode-ai/ui/context"
 import { createGlobalEmitter } from "@solid-primitives/event-bus"
 import { batch, onCleanup } from "solid-js"
 import z from "zod"
+import { workspacePathKey } from "@/context/file/path"
 import { createSdkForServer } from "@/utils/server"
 import { useLanguage } from "./language"
 import { usePlatform } from "./platform"
@@ -43,7 +44,7 @@ export const { use: useGlobalSDK, provider: GlobalSDKProvider } = createSimpleCo
       [key: string]: Event
     }>()
 
-    type Queued = { directory: string; payload: Event }
+    type Queued = { directory: string; id: string; payload: Event }
     const FLUSH_FRAME_MS = 16
     const STREAM_YIELD_MS = 8
     const RECONNECT_DELAY_MS = 250
@@ -55,6 +56,8 @@ export const { use: useGlobalSDK, provider: GlobalSDKProvider } = createSimpleCo
     let timer: ReturnType<typeof setTimeout> | undefined
     let last = 0
 
+    const keyDir = (directory: string) => (directory === "global" ? directory : workspacePathKey(directory))
+
     const deltaKey = (directory: string, messageID: string, partID: string) => `${directory}:${messageID}:${partID}`
 
     const key = (directory: string, payload: Event) => {
@@ -85,7 +88,7 @@ export const { use: useGlobalSDK, provider: GlobalSDKProvider } = createSimpleCo
         for (const event of events) {
           if (skip && event.payload.type === "message.part.delta") {
             const props = event.payload.properties
-            if (skip.has(deltaKey(event.directory, props.messageID, props.partID))) continue
+            if (skip.has(deltaKey(event.id, props.messageID, props.partID))) continue
           }
           emitter.emit(event.directory, event.payload)
         }
@@ -149,21 +152,22 @@ export const { use: useGlobalSDK, provider: GlobalSDKProvider } = createSimpleCo
             resetHeartbeat()
             streamErrorLogged = false
             const directory = event.directory ?? "global"
+            const id = keyDir(directory)
             const payload = event.payload
-            const k = key(directory, payload)
+            const k = key(id, payload)
             if (k) {
               const i = coalesced.get(k)
               if (i !== undefined) {
-                queue[i] = { directory, payload }
+                queue[i] = { directory, id, payload }
                 if (payload.type === "message.part.updated") {
                   const part = payload.properties.part
-                  staleDeltas.add(deltaKey(directory, part.messageID, part.id))
+                  staleDeltas.add(deltaKey(id, part.messageID, part.id))
                 }
                 continue
               }
               coalesced.set(k, queue.length)
             }
-            queue.push({ directory, payload })
+            queue.push({ directory, id, payload })
             schedule()
 
             if (Date.now() - yielded < STREAM_YIELD_MS) continue
diff --git a/packages/app/src/context/global-sync.test.ts b/packages/app/src/context/global-sync.test.ts
index 93e9c4175557..c627e1ddbe4b 100644
--- a/packages/app/src/context/global-sync.test.ts
+++ b/packages/app/src/context/global-sync.test.ts
@@ -1,25 +1,28 @@
 import { describe, expect, test } from "bun:test"
+import { workspacePathKey } from "@/context/file/path"
 import { canDisposeDirectory, pickDirectoriesToEvict } from "./global-sync/eviction"
 import { estimateRootSessionTotal, loadRootSessionsWithFallback } from "./global-sync/session-load"
 
+const key = (input: string) => workspacePathKey(input)
+
 describe("pickDirectoriesToEvict", () => {
   test("keeps pinned stores and evicts idle stores", () => {
     const now = 5_000
     const picks = pickDirectoriesToEvict({
-      stores: ["a", "b", "c", "d"],
+      stores: [key("a"), key("b"), key("c"), key("d")],
       state: new Map([
-        ["a", { lastAccessAt: 1_000 }],
-        ["b", { lastAccessAt: 4_900 }],
-        ["c", { lastAccessAt: 4_800 }],
-        ["d", { lastAccessAt: 3_000 }],
+        [key("a"), { lastAccessAt: 1_000 }],
+        [key("b"), { lastAccessAt: 4_900 }],
+        [key("c"), { lastAccessAt: 4_800 }],
+        [key("d"), { lastAccessAt: 3_000 }],
       ]),
-      pins: new Set(["a"]),
+      pins: new Set([key("a")]),
       max: 2,
       ttl: 1_500,
       now,
     })
 
-    expect(picks).toEqual(["d", "c"])
+    expect(picks.map(String)).toEqual(["d", "c"])
   })
 })
 
@@ -81,7 +84,7 @@ describe("canDisposeDirectory", () => {
   test("rejects pinned or inflight directories", () => {
     expect(
       canDisposeDirectory({
-        directory: "dir",
+        directory: key("dir"),
         hasStore: true,
         pinned: true,
         booting: false,
@@ -90,7 +93,7 @@ describe("canDisposeDirectory", () => {
     ).toBe(false)
     expect(
       canDisposeDirectory({
-        directory: "dir",
+        directory: key("dir"),
         hasStore: true,
         pinned: false,
         booting: true,
@@ -99,7 +102,7 @@ describe("canDisposeDirectory", () => {
     ).toBe(false)
     expect(
       canDisposeDirectory({
-        directory: "dir",
+        directory: key("dir"),
         hasStore: true,
         pinned: false,
         booting: false,
@@ -111,7 +114,7 @@ describe("canDisposeDirectory", () => {
   test("accepts idle unpinned directory store", () => {
     expect(
       canDisposeDirectory({
-        directory: "dir",
+        directory: key("dir"),
         hasStore: true,
         pinned: false,
         booting: false,
diff --git a/packages/app/src/context/global-sync.tsx b/packages/app/src/context/global-sync.tsx
index 2d1e50135350..e7f58f829020 100644
--- a/packages/app/src/context/global-sync.tsx
+++ b/packages/app/src/context/global-sync.tsx
@@ -36,6 +36,7 @@ import type { ProjectMeta } from "./global-sync/types"
 import { SESSION_RECENT_LIMIT } from "./global-sync/types"
 import { sanitizeProject } from "./global-sync/utils"
 import { formatServerError } from "@/utils/server-errors"
+import { workspacePathKey, type WorkspaceKey, type WorkspacePath } from "@/context/file/path"
 
 type GlobalStore = {
   ready: boolean
@@ -57,10 +58,10 @@ function createGlobalSync() {
   const owner = getOwner()
   if (!owner) throw new Error("GlobalSync must be created within owner")
 
-  const sdkCache = new Map<string, OpencodeClient>()
-  const booting = new Map<string, Promise<void>>()
-  const sessionLoads = new Map<string, Promise<void>>()
-  const sessionMeta = new Map<string, { limit: number }>()
+  const sdkCache = new Map<WorkspaceKey, OpencodeClient>()
+  const booting = new Map<WorkspaceKey, Promise<void>>()
+  const sessionLoads = new Map<WorkspaceKey, Promise<void>>()
+  const sessionMeta = new Map<WorkspaceKey, { limit: number }>()
 
   const [projectCache, setProjectCache, projectInit] = persisted(
     Persist.global("globalSync.project", ["globalSync.project.v1"]),
@@ -69,7 +70,14 @@ function createGlobalSync() {
 
   const [globalStore, setGlobalStore] = createStore<GlobalStore>({
     ready: false,
-    path: { state: "", config: "", worktree: "", directory: "", home: "" },
+    path: {
+      os: "linux",
+      state: "",
+      config: "",
+      worktree: "",
+      directory: "",
+      home: "",
+    },
     project: projectCache.value,
     session_todo: {},
     provider: { all: [], connected: [], default: {} },
@@ -80,6 +88,10 @@ function createGlobalSync() {
 
   let active = true
   let projectWritten = false
+  const eventKey = (name: string) => {
+    if (name === "global") return "global" as const
+    return workspacePathKey(name as WorkspacePath)
+  }
 
   onCleanup(() => {
     active = false
@@ -148,7 +160,7 @@ function createGlobalSync() {
   const queue = createRefreshQueue({
     paused,
     bootstrap,
-    bootstrapInstance,
+    bootstrapInstance: bootstrapInstanceKey,
   })
 
   const children = createChildStoreManager({
@@ -156,7 +168,7 @@ function createGlobalSync() {
     isBooting: (directory) => booting.has(directory),
     isLoadingSessions: (directory) => sessionLoads.has(directory),
     onBootstrap: (directory) => {
-      void bootstrapInstance(directory)
+      void bootstrapInstanceKey(directory)
     },
     onDispose: (directory) => {
       queue.clear(directory)
@@ -167,7 +179,7 @@ function createGlobalSync() {
     translate: language.t,
   })
 
-  const sdkFor = (directory: string) => {
+  const sdkFor = (directory: WorkspaceKey) => {
     const cached = sdkCache.get(directory)
     if (cached) return cached
     const sdk = globalSDK.createClient({
@@ -178,7 +190,7 @@ function createGlobalSync() {
     return sdk
   }
 
-  async function loadSessions(directory: string) {
+  async function loadSessionsKey(directory: WorkspaceKey) {
     const pending = sessionLoads.get(directory)
     if (pending) return pending
 
@@ -245,8 +257,11 @@ function createGlobalSync() {
     return promise
   }
 
-  async function bootstrapInstance(directory: string) {
-    if (!directory) return
+  function loadSessions(directory: WorkspacePath) {
+    return loadSessionsKey(workspacePathKey(directory))
+  }
+
+  async function bootstrapInstanceKey(directory: WorkspaceKey) {
     const pending = booting.get(directory)
     if (pending) return pending
 
@@ -276,7 +291,7 @@ function createGlobalSync() {
   }
 
   const unsub = globalSDK.event.listen((e) => {
-    const directory = e.name
+    const directory = eventKey(e.name)
     const event = e.details
 
     if (directory === "global") {
@@ -287,7 +302,7 @@ function createGlobalSync() {
         setGlobalProject: setProjects,
       })
       if (event.type === "server.connected" || event.type === "global.disposed") {
-        for (const directory of Object.keys(children.children)) {
+        for (const directory of Object.keys(children.children) as WorkspaceKey[]) {
           queue.push(directory)
         }
       }
@@ -303,7 +318,7 @@ function createGlobalSync() {
       directory,
       store,
       setStore,
-      push: queue.push,
+      push: (next) => queue.push(workspacePathKey(next)),
       setSessionTodo,
       vcsCache: children.vcsCache.get(directory),
       loadLsp: () => {
@@ -319,8 +334,8 @@ function createGlobalSync() {
     queue.dispose()
   })
   onCleanup(() => {
-    for (const directory of Object.keys(children.children)) {
-      children.disposeDirectory(directory)
+    for (const directory of Object.keys(children.children) as WorkspaceKey[]) {
+      children.dispose(directory)
     }
   })
 
@@ -344,14 +359,17 @@ function createGlobalSync() {
 
   const projectApi = {
     loadSessions,
-    meta(directory: string, patch: ProjectMeta) {
-      children.projectMeta(directory, patch)
+    meta(directory: WorkspacePath, patch: ProjectMeta) {
+      children.projectMeta(workspacePathKey(directory), patch)
     },
-    icon(directory: string, value: string | undefined) {
-      children.projectIcon(directory, value)
+    icon(directory: WorkspacePath, value: string | undefined) {
+      children.projectIcon(workspacePathKey(directory), value)
     },
   }
 
+  const child = (directory: WorkspacePath, options?: { bootstrap?: boolean }) =>
+    children.child(workspacePathKey(directory), options)
+
   const updateConfig = async (config: Config) => {
     setGlobalStore("reload", "pending")
     return globalSDK.client.global.config
@@ -377,8 +395,9 @@ function createGlobalSync() {
     get error() {
       return globalStore.error
     },
-    child: children.child,
-    peek: children.peek,
+    child,
+    peek: (directory: WorkspacePath, options?: { bootstrap?: boolean }) =>
+      children.peek(workspacePathKey(directory), options),
     bootstrap,
     updateConfig,
     project: projectApi,
diff --git a/packages/app/src/context/global-sync/bootstrap.ts b/packages/app/src/context/global-sync/bootstrap.ts
index 13494b7ade0a..76a9c0e7b889 100644
--- a/packages/app/src/context/global-sync/bootstrap.ts
+++ b/packages/app/src/context/global-sync/bootstrap.ts
@@ -17,6 +17,7 @@ import { reconcile, type SetStoreFunction, type Store } from "solid-js/store"
 import type { State, VcsCache } from "./types"
 import { cmp, normalizeProviderList } from "./utils"
 import { formatServerError } from "@/utils/server-errors"
+import type { WorkspacePath } from "@/context/file/path"
 
 type GlobalStore = {
   ready: boolean
@@ -112,12 +113,12 @@ function groupBySession<T extends { id: string; sessionID: string }>(input: T[])
 }
 
 export async function bootstrapDirectory(input: {
-  directory: string
+  directory: WorkspacePath
   sdk: OpencodeClient
   store: Store<State>
   setStore: SetStoreFunction<State>
   vcsCache: VcsCache
-  loadSessions: (directory: string) => Promise<void> | void
+  loadSessions: (directory: WorkspacePath) => Promise<void> | void
   translate: (key: string, vars?: Record<string, string | number>) => string
 }) {
   if (input.store.status !== "complete") input.setStore("status", "loading")
diff --git a/packages/app/src/context/global-sync/child-store.test.ts b/packages/app/src/context/global-sync/child-store.test.ts
index eee763f16dee..a9171271e19b 100644
--- a/packages/app/src/context/global-sync/child-store.test.ts
+++ b/packages/app/src/context/global-sync/child-store.test.ts
@@ -1,6 +1,7 @@
 import { describe, expect, test } from "bun:test"
 import { createRoot, getOwner } from "solid-js"
 import { createStore } from "solid-js/store"
+import { workspacePathKey } from "@/context/file/path"
 import type { State } from "./types"
 import { createChildStoreManager } from "./child-store"
 
@@ -25,14 +26,38 @@ describe("createChildStoreManager", () => {
     })
 
     Array.from({ length: 30 }, (_, index) => `/pinned-${index}`).forEach((directory) => {
-      manager.children[directory] = child()
-      manager.pin(directory)
+      manager.children[workspacePathKey(directory)] = child()
+      manager.pin(workspacePathKey(directory))
     })
 
     const directory = "/active"
-    manager.children[directory] = child()
-    manager.mark(directory)
+    manager.children[workspacePathKey(directory)] = child()
+    manager.mark(workspacePathKey(directory))
 
-    expect(manager.children[directory]).toBeDefined()
+    expect(manager.children[workspacePathKey(directory)]).toBeDefined()
+  })
+
+  test("reuses canonical workspace keys for equivalent directories", () => {
+    const owner = createRoot((dispose) => {
+      const current = getOwner()
+      dispose()
+      return current
+    })
+    if (!owner) throw new Error("owner required")
+
+    const manager = createChildStoreManager({
+      owner,
+      isBooting: () => false,
+      isLoadingSessions: () => false,
+      onBootstrap() {},
+      onDispose() {},
+      translate: (key) => key,
+    })
+
+    const store = child()
+    manager.children[workspacePathKey("c:/repo")] = store
+
+    expect(manager.child(workspacePathKey("C:\\Repo\\"), { bootstrap: false })).toBe(store)
+    expect(Object.keys(manager.children)).toEqual([workspacePathKey("c:/repo")])
   })
 })
diff --git a/packages/app/src/context/global-sync/child-store.ts b/packages/app/src/context/global-sync/child-store.ts
index 70668350ec20..2c2e7ba1b566 100644
--- a/packages/app/src/context/global-sync/child-store.ts
+++ b/packages/app/src/context/global-sync/child-store.ts
@@ -2,6 +2,7 @@ import { createRoot, getOwner, onCleanup, runWithOwner, type Owner } from "solid
 import { createStore, type SetStoreFunction, type Store } from "solid-js/store"
 import { Persist, persisted } from "@/utils/persist"
 import type { VcsInfo } from "@opencode-ai/sdk/v2/client"
+import type { WorkspaceKey } from "@/context/file/path"
 import {
   DIR_IDLE_TTL_MS,
   MAX_DIR_STORES,
@@ -17,35 +18,34 @@ import { canDisposeDirectory, pickDirectoriesToEvict } from "./eviction"
 
 export function createChildStoreManager(input: {
   owner: Owner
-  isBooting: (directory: string) => boolean
-  isLoadingSessions: (directory: string) => boolean
-  onBootstrap: (directory: string) => void
-  onDispose: (directory: string) => void
+  isBooting: (directory: WorkspaceKey) => boolean
+  isLoadingSessions: (directory: WorkspaceKey) => boolean
+  onBootstrap: (directory: WorkspaceKey) => void
+  onDispose: (directory: WorkspaceKey) => void
   translate: (key: string, vars?: Record<string, string | number>) => string
 }) {
-  const children: Record<string, [Store<State>, SetStoreFunction<State>]> = {}
-  const vcsCache = new Map<string, VcsCache>()
-  const metaCache = new Map<string, MetaCache>()
-  const iconCache = new Map<string, IconCache>()
-  const lifecycle = new Map<string, DirState>()
-  const pins = new Map<string, number>()
-  const ownerPins = new WeakMap<object, Set<string>>()
-  const disposers = new Map<string, () => void>()
+  type ChildStore = [Store<State>, SetStoreFunction<State>]
 
-  const mark = (directory: string) => {
-    if (!directory) return
+  const children: Record<WorkspaceKey, ChildStore> = {} as Record<WorkspaceKey, ChildStore>
+  const vcsCache = new Map<WorkspaceKey, VcsCache>()
+  const metaCache = new Map<WorkspaceKey, MetaCache>()
+  const iconCache = new Map<WorkspaceKey, IconCache>()
+  const lifecycle = new Map<WorkspaceKey, DirState>()
+  const pins = new Map<WorkspaceKey, number>()
+  const ownerPins = new WeakMap<object, Set<WorkspaceKey>>()
+  const disposers = new Map<WorkspaceKey, () => void>()
+
+  const mark = (directory: WorkspaceKey) => {
     lifecycle.set(directory, { lastAccessAt: Date.now() })
     runEviction(directory)
   }
 
-  const pin = (directory: string) => {
-    if (!directory) return
+  const pin = (directory: WorkspaceKey) => {
     pins.set(directory, (pins.get(directory) ?? 0) + 1)
     mark(directory)
   }
 
-  const unpin = (directory: string) => {
-    if (!directory) return
+  const unpin = (directory: WorkspaceKey) => {
     const next = (pins.get(directory) ?? 0) - 1
     if (next > 0) {
       pins.set(directory, next)
@@ -55,29 +55,29 @@ export function createChildStoreManager(input: {
     runEviction()
   }
 
-  const pinned = (directory: string) => (pins.get(directory) ?? 0) > 0
+  const pinned = (directory: WorkspaceKey) => (pins.get(directory) ?? 0) > 0
 
-  const pinForOwner = (directory: string) => {
+  const pinForOwner = (directory: WorkspaceKey) => {
     const current = getOwner()
     if (!current) return
     if (current === input.owner) return
-    const key = current as object
-    const set = ownerPins.get(key)
+    const owner = current as object
+    const set = ownerPins.get(owner)
     if (set?.has(directory)) return
     if (set) set.add(directory)
-    if (!set) ownerPins.set(key, new Set([directory]))
+    if (!set) ownerPins.set(owner, new Set([directory]))
     pin(directory)
     onCleanup(() => {
-      const set = ownerPins.get(key)
+      const set = ownerPins.get(owner)
       if (set) {
         set.delete(directory)
-        if (set.size === 0) ownerPins.delete(key)
+        if (set.size === 0) ownerPins.delete(owner)
       }
       unpin(directory)
     })
   }
 
-  function disposeDirectory(directory: string) {
+  function dispose(directory: WorkspaceKey) {
     if (
       !canDisposeDirectory({
         directory,
@@ -104,8 +104,8 @@ export function createChildStoreManager(input: {
     return true
   }
 
-  function runEviction(skip?: string) {
-    const stores = Object.keys(children)
+  function runEviction(skip?: WorkspaceKey) {
+    const stores = Object.keys(children) as WorkspaceKey[]
     if (stores.length === 0) return
     const list = pickDirectoriesToEvict({
       stores,
@@ -117,12 +117,11 @@ export function createChildStoreManager(input: {
     }).filter((directory) => directory !== skip)
     if (list.length === 0) return
     for (const directory of list) {
-      if (!disposeDirectory(directory)) continue
+      if (!dispose(directory)) continue
     }
   }
 
-  function ensureChild(directory: string) {
-    if (!directory) console.error("No directory provided")
+  function ensureChild(directory: WorkspaceKey) {
     if (!children[directory]) {
       const vcs = runWithOwner(input.owner, () =>
         persisted(
@@ -162,7 +161,14 @@ export function createChildStoreManager(input: {
             icon: initialIcon,
             provider: { all: [], connected: [], default: {} },
             config: {},
-            path: { state: "", config: "", worktree: "", directory: "", home: "" },
+            path: {
+              os: "linux",
+              state: "",
+              config: "",
+              worktree: "",
+              directory: "",
+              home: "",
+            },
             status: "loading" as const,
             agent: [],
             command: [],
@@ -216,7 +222,7 @@ export function createChildStoreManager(input: {
     return childStore
   }
 
-  function child(directory: string, options: ChildOptions = {}) {
+  function child(directory: WorkspaceKey, options: ChildOptions = {}) {
     const childStore = ensureChild(directory)
     pinForOwner(directory)
     const shouldBootstrap = options.bootstrap ?? true
@@ -226,7 +232,7 @@ export function createChildStoreManager(input: {
     return childStore
   }
 
-  function peek(directory: string, options: ChildOptions = {}) {
+  function peek(directory: WorkspaceKey, options: ChildOptions = {}) {
     const childStore = ensureChild(directory)
     const shouldBootstrap = options.bootstrap ?? true
     if (shouldBootstrap && childStore[0].status === "loading") {
@@ -235,7 +241,7 @@ export function createChildStoreManager(input: {
     return childStore
   }
 
-  function projectMeta(directory: string, patch: ProjectMeta) {
+  function projectMeta(directory: WorkspaceKey, patch: ProjectMeta) {
     const [store, setStore] = ensureChild(directory)
     const cached = metaCache.get(directory)
     if (!cached) return
@@ -252,7 +258,7 @@ export function createChildStoreManager(input: {
     setStore("projectMeta", next)
   }
 
-  function projectIcon(directory: string, value: string | undefined) {
+  function projectIcon(directory: WorkspaceKey, value: string | undefined) {
     const [store, setStore] = ensureChild(directory)
     const cached = iconCache.get(directory)
     if (!cached) return
@@ -272,7 +278,7 @@ export function createChildStoreManager(input: {
     pin,
     unpin,
     pinned,
-    disposeDirectory,
+    dispose,
     runEviction,
     vcsCache,
     metaCache,
diff --git a/packages/app/src/context/global-sync/event-reducer.test.ts b/packages/app/src/context/global-sync/event-reducer.test.ts
index cf2da135cbbc..2f97247c50f6 100644
--- a/packages/app/src/context/global-sync/event-reducer.test.ts
+++ b/packages/app/src/context/global-sync/event-reducer.test.ts
@@ -1,8 +1,8 @@
 import { describe, expect, test } from "bun:test"
-import type { Message, Part, PermissionRequest, Project, QuestionRequest, Session } from "@opencode-ai/sdk/v2/client"
+import type { FileDiff, Message, Part, PermissionRequest, Project, QuestionRequest, Session } from "@opencode-ai/sdk/v2/client"
 import { createStore } from "solid-js/store"
 import type { State } from "./types"
-import { applyDirectoryEvent, applyGlobalEvent, cleanupDroppedSessionCaches } from "./event-reducer"
+import { applyDirectoryEvent, applyGlobalEvent, cleanupDroppedSessionCaches, normalizeSessionDiffs } from "./event-reducer"
 
 const rootSession = (input: { id: string; parentID?: string; archived?: number }) =>
   ({
@@ -515,6 +515,15 @@ describe("applyDirectoryEvent", () => {
     expect(cacheStore.value).toEqual({ branch: "feature/test" })
   })
 
+  test("normalizes session diff file keys across slash variants", () => {
+    const diff = normalizeSessionDiffs([
+      { file: "src\\app.ts", status: "modified", before: "a", after: "b", additions: 1, deletions: 0 },
+      { file: "src/app.ts", status: "deleted", before: "a", after: "", additions: 0, deletions: 1 },
+    ] as FileDiff[])
+
+    expect(diff).toEqual([{ file: "src/app.ts", status: "deleted", before: "a", after: "", additions: 0, deletions: 1 }])
+  })
+
   test("routes disposal and lsp events to side-effect handlers", () => {
     const [store, setStore] = createStore(baseState())
     const pushes: string[] = []
diff --git a/packages/app/src/context/global-sync/event-reducer.ts b/packages/app/src/context/global-sync/event-reducer.ts
index b8eda0573f7b..1f91fe575f60 100644
--- a/packages/app/src/context/global-sync/event-reducer.ts
+++ b/packages/app/src/context/global-sync/event-reducer.ts
@@ -14,6 +14,20 @@ import type {
 import type { State, VcsCache } from "./types"
 import { trimSessions } from "./session-trim"
 import { dropSessionCaches } from "./session-cache"
+import { filePathKey, type WorkspacePath } from "@/context/file/path"
+
+export function normalizeSessionDiffs(diffs: FileDiff[]) {
+  const order: string[] = []
+  const map = new Map<string, FileDiff>()
+
+  for (const diff of diffs) {
+    const file = filePathKey(diff.file)
+    if (!map.has(file)) order.push(file)
+    map.set(file, { ...diff, file })
+  }
+
+  return order.map((file) => map.get(file)!)
+}
 
 export function applyGlobalEvent(input: {
   event: { type: string; properties?: unknown }
@@ -88,7 +102,7 @@ export function applyDirectoryEvent(input: {
   store: Store<State>
   setStore: SetStoreFunction<State>
   push: (directory: string) => void
-  directory: string
+  directory: WorkspacePath
   loadLsp: () => void
   vcsCache?: VcsCache
   setSessionTodo?: (sessionID: string, todos: Todo[] | undefined) => void
@@ -160,7 +174,7 @@ export function applyDirectoryEvent(input: {
     }
     case "session.diff": {
       const props = event.properties as { sessionID: string; diff: FileDiff[] }
-      input.setStore("session_diff", props.sessionID, reconcile(props.diff, { key: "file" }))
+      input.setStore("session_diff", props.sessionID, reconcile(normalizeSessionDiffs(props.diff), { key: "file" }))
       break
     }
     case "todo.updated": {
diff --git a/packages/app/src/context/global-sync/eviction.ts b/packages/app/src/context/global-sync/eviction.ts
index 676a6ee17e1f..a3aff3c6614d 100644
--- a/packages/app/src/context/global-sync/eviction.ts
+++ b/packages/app/src/context/global-sync/eviction.ts
@@ -7,7 +7,7 @@ export function pickDirectoriesToEvict(input: EvictPlan) {
     .filter((dir) => !input.pins.has(dir))
     .slice()
     .sort((a, b) => (input.state.get(a)?.lastAccessAt ?? 0) - (input.state.get(b)?.lastAccessAt ?? 0))
-  const output: string[] = []
+  const output: EvictPlan["stores"] = []
   for (const dir of sorted) {
     const last = input.state.get(dir)?.lastAccessAt ?? 0
     const idle = input.now - last >= input.ttl
diff --git a/packages/app/src/context/global-sync/queue.ts b/packages/app/src/context/global-sync/queue.ts
index c3468583b930..e1566444a1b1 100644
--- a/packages/app/src/context/global-sync/queue.ts
+++ b/packages/app/src/context/global-sync/queue.ts
@@ -1,11 +1,13 @@
+import type { WorkspaceKey } from "@/context/file/path"
+
 type QueueInput = {
   paused: () => boolean
   bootstrap: () => Promise<void>
-  bootstrapInstance: (directory: string) => Promise<void> | void
+  bootstrapInstance: (directory: WorkspaceKey) => Promise<void> | void
 }
 
 export function createRefreshQueue(input: QueueInput) {
-  const queued = new Set<string>()
+  const queued = new Set<WorkspaceKey>()
   let root = false
   let running = false
   let timer: ReturnType<typeof setTimeout> | undefined
@@ -13,8 +15,8 @@ export function createRefreshQueue(input: QueueInput) {
   const tick = () => new Promise<void>((resolve) => setTimeout(resolve, 0))
 
   const take = (count: number) => {
-    if (queued.size === 0) return [] as string[]
-    const items: string[] = []
+    if (queued.size === 0) return [] as WorkspaceKey[]
+    const items: WorkspaceKey[] = []
     for (const item of queued) {
       queued.delete(item)
       items.push(item)
@@ -31,8 +33,7 @@ export function createRefreshQueue(input: QueueInput) {
     }, 0)
   }
 
-  const push = (directory: string) => {
-    if (!directory) return
+  const push = (directory: WorkspaceKey) => {
     queued.add(directory)
     if (input.paused()) return
     schedule()
@@ -71,7 +72,7 @@ export function createRefreshQueue(input: QueueInput) {
   return {
     push,
     refresh,
-    clear(directory: string) {
+    clear(directory: WorkspaceKey) {
       queued.delete(directory)
     },
     dispose() {
diff --git a/packages/app/src/context/global-sync/session-prefetch.test.ts b/packages/app/src/context/global-sync/session-prefetch.test.ts
index 1ce833469872..28f18dfe819c 100644
--- a/packages/app/src/context/global-sync/session-prefetch.test.ts
+++ b/packages/app/src/context/global-sync/session-prefetch.test.ts
@@ -63,6 +63,25 @@ describe("session prefetch", () => {
     expect(getSessionPrefetch("/tmp/e", "ses_1")).toEqual({ limit: 30, cursor: "c", complete: true, at: 3 })
   })
 
+  test("collapses equivalent workspace paths", () => {
+    clearSessionPrefetch("C:/Repo", ["ses_3"])
+
+    setSessionPrefetch({
+      directory: "C:\\Repo\\",
+      sessionID: "ses_3",
+      limit: 40,
+      cursor: "win",
+      complete: false,
+      at: 7,
+    })
+
+    expect(getSessionPrefetch("c:/repo", "ses_3")).toEqual({ limit: 40, cursor: "win", complete: false, at: 7 })
+
+    clearSessionPrefetchDirectory("c:/repo")
+
+    expect(getSessionPrefetch("C:\\Repo\\", "ses_3")).toBeUndefined()
+  })
+
   test("refreshes stale first-page prefetched history", () => {
     expect(
       shouldSkipSessionPrefetch({
diff --git a/packages/app/src/context/global-sync/session-prefetch.ts b/packages/app/src/context/global-sync/session-prefetch.ts
index 608561f855c7..784880f1715f 100644
--- a/packages/app/src/context/global-sync/session-prefetch.ts
+++ b/packages/app/src/context/global-sync/session-prefetch.ts
@@ -1,4 +1,8 @@
-const key = (directory: string, sessionID: string) => `${directory}\n${sessionID}`
+import { workspacePathKey, type WorkspacePath } from "@/context/file/path"
+
+const dir = (directory: WorkspacePath) => workspacePathKey(directory)
+
+const key = (directory: WorkspacePath, sessionID: string) => `${dir(directory)}\n${sessionID}`
 
 export const SESSION_PREFETCH_TTL = 15_000
 
@@ -27,11 +31,11 @@ const rev = new Map<string, number>()
 
 const version = (id: string) => rev.get(id) ?? 0
 
-export function getSessionPrefetch(directory: string, sessionID: string) {
+export function getSessionPrefetch(directory: WorkspacePath, sessionID: string) {
   return cache.get(key(directory, sessionID))
 }
 
-export function getSessionPrefetchPromise(directory: string, sessionID: string) {
+export function getSessionPrefetchPromise(directory: WorkspacePath, sessionID: string) {
   return inflight.get(key(directory, sessionID))
 }
 
@@ -39,12 +43,12 @@ export function clearSessionPrefetchInflight() {
   inflight.clear()
 }
 
-export function isSessionPrefetchCurrent(directory: string, sessionID: string, value: number) {
+export function isSessionPrefetchCurrent(directory: WorkspacePath, sessionID: string, value: number) {
   return version(key(directory, sessionID)) === value
 }
 
 export function runSessionPrefetch(input: {
-  directory: string
+  directory: WorkspacePath
   sessionID: string
   task: (value: number) => Promise<Meta | undefined>
 }) {
@@ -63,7 +67,7 @@ export function runSessionPrefetch(input: {
 }
 
 export function setSessionPrefetch(input: {
-  directory: string
+  directory: WorkspacePath
   sessionID: string
   limit: number
   cursor?: string
@@ -78,7 +82,7 @@ export function setSessionPrefetch(input: {
   })
 }
 
-export function clearSessionPrefetch(directory: string, sessionIDs: Iterable<string>) {
+export function clearSessionPrefetch(directory: WorkspacePath, sessionIDs: Iterable<string>) {
   for (const sessionID of sessionIDs) {
     if (!sessionID) continue
     const id = key(directory, sessionID)
@@ -88,8 +92,8 @@ export function clearSessionPrefetch(directory: string, sessionIDs: Iterable<str
   }
 }
 
-export function clearSessionPrefetchDirectory(directory: string) {
-  const prefix = `${directory}\n`
+export function clearSessionPrefetchDirectory(directory: WorkspacePath) {
+  const prefix = `${dir(directory)}\n`
   const keys = new Set([...cache.keys(), ...inflight.keys()])
   for (const id of keys) {
     if (!id.startsWith(prefix)) continue
diff --git a/packages/app/src/context/global-sync/types.ts b/packages/app/src/context/global-sync/types.ts
index c61dc337d8b9..dc10bf18f974 100644
--- a/packages/app/src/context/global-sync/types.ts
+++ b/packages/app/src/context/global-sync/types.ts
@@ -19,6 +19,7 @@ import type {
 } from "@opencode-ai/sdk/v2/client"
 import type { Accessor } from "solid-js"
 import type { SetStoreFunction, Store } from "solid-js/store"
+import type { WorkspaceKey, WorkspacePath } from "@/context/file/path"
 
 export type ProjectMeta = {
   name?: string
@@ -99,16 +100,16 @@ export type DirState = {
 }
 
 export type EvictPlan = {
-  stores: string[]
-  state: Map<string, DirState>
-  pins: Set<string>
+  stores: WorkspaceKey[]
+  state: Map<WorkspaceKey, DirState>
+  pins: Set<WorkspaceKey>
   max: number
   ttl: number
   now: number
 }
 
 export type DisposeCheck = {
-  directory: string
+  directory: WorkspaceKey
   hasStore: boolean
   pinned: boolean
   booting: boolean
@@ -116,9 +117,9 @@ export type DisposeCheck = {
 }
 
 export type RootLoadArgs = {
-  directory: string
+  directory: WorkspacePath
   limit: number
-  list: (query: { directory: string; roots: true; limit?: number }) => Promise<{ data?: Session[] }>
+  list: (query: { directory: WorkspacePath; roots: true; limit?: number }) => Promise<{ data?: Session[] }>
 }
 
 export type RootLoadResult = {
diff --git a/packages/app/src/context/layout.test.ts b/packages/app/src/context/layout.test.ts
index 582d5edbd29f..ce8cfcdbe285 100644
--- a/packages/app/src/context/layout.test.ts
+++ b/packages/app/src/context/layout.test.ts
@@ -1,6 +1,7 @@
 import { describe, expect, test } from "bun:test"
 import { createRoot, createSignal } from "solid-js"
-import { createSessionKeyReader, ensureSessionKey, pruneSessionKeys } from "./layout"
+import { base64Encode } from "@opencode-ai/util/encode"
+import { createSessionKeyReader, ensureSessionKey, normalizeStoredSessionTabs, pruneSessionKeys } from "./layout"
 
 describe("layout session-key helpers", () => {
   test("couples touch and scroll seed in order", () => {
@@ -19,17 +20,20 @@ describe("layout session-key helpers", () => {
     const seen: string[] = []
 
     createRoot((dispose) => {
-      const [key, setKey] = createSignal("dir/one")
-      const read = createSessionKeyReader(key, (value) => seen.push(value))
+      const [key, setKey] = createSignal(`${base64Encode("C:\\Repo\\")}/one`)
+      const read = createSessionKeyReader(key, (value) => {
+        seen.push(value)
+        return ensureSessionKey(value, () => {}, () => {})
+      })
 
-      expect(read()).toBe("dir/one")
-      setKey("dir/two")
-      expect(read()).toBe("dir/two")
+      expect(read()).toBe(`${base64Encode("c:/repo")}/one`)
+      setKey(`${base64Encode("C:\\Repo\\")}/two`)
+      expect(read()).toBe(`${base64Encode("c:/repo")}/two`)
 
       dispose()
     })
 
-    expect(seen).toEqual(["dir/one", "dir/two"])
+    expect(seen).toEqual([`${base64Encode("C:\\Repo\\")}/one`, `${base64Encode("C:\\Repo\\")}/two`])
   })
 })
 
@@ -67,3 +71,19 @@ describe("pruneSessionKeys", () => {
     expect(drop).toEqual([])
   })
 })
+
+describe("normalizeStoredSessionTabs", () => {
+  test("upgrades legacy file tabs without touching real file URIs", () => {
+    const key = `${base64Encode("/repo")}/session`
+
+    expect(
+      normalizeStoredSessionTabs(key, {
+        all: ["context", "file://src/a.ts", "tab:file:src/a.ts", "file:///repo/src/b.ts"],
+        active: "file://src/a.ts",
+      }),
+    ).toEqual({
+      all: ["context", "tab:file:src/a.ts", "file:///repo/src/b.ts"],
+      active: "tab:file:src/a.ts",
+    })
+  })
+})
diff --git a/packages/app/src/context/layout.tsx b/packages/app/src/context/layout.tsx
index 78928118d72a..577d04910470 100644
--- a/packages/app/src/context/layout.tsx
+++ b/packages/app/src/context/layout.tsx
@@ -1,21 +1,42 @@
 import { createStore, produce } from "solid-js/store"
 import { batch, createEffect, createMemo, onCleanup, onMount, type Accessor } from "solid-js"
 import { createSimpleContext } from "@opencode-ai/ui/context"
+import { pathEqual } from "@opencode-ai/util/path"
 import { useGlobalSync } from "./global-sync"
 import { useGlobalSDK } from "./global-sdk"
 import { useServer } from "./server"
 import { usePlatform } from "./platform"
 import { Project } from "@opencode-ai/sdk/v2"
 import { Persist, persisted, removePersisted } from "@/utils/persist"
-import { decode64 } from "@/utils/base64"
+import { migrateLayoutPaths } from "@/utils/persist-path"
+import { normalizeSessionKey, sessionDirKey, sessionParts, sessionPathHelpers } from "@/utils/session-key"
 import { same } from "@/utils/same"
 import { createScrollPersistence, type SessionScroll } from "./layout-scroll"
-import { createPathHelpers } from "./file/path"
+import { reviewPathKey, workspacePathKey, type ReviewPath, type WorkspaceKey, type WorkspacePath } from "./file/path"
 
 const AVATAR_COLOR_KEYS = ["pink", "mint", "orange", "purple", "cyan", "lime"] as const
 const DEFAULT_PANEL_WIDTH = 344
 const DEFAULT_SESSION_WIDTH = 600
 const DEFAULT_TERMINAL_HEIGHT = 280
+const reviewPaths = (paths: readonly ReviewPath[]) => {
+  const seen = new Set<string>()
+  const out: ReviewPath[] = []
+
+  for (const path of paths) {
+    const id = reviewPathKey(path)
+    if (seen.has(id)) continue
+    seen.add(id)
+    out.push(path)
+  }
+
+  return out
+}
+const sameReviewPaths = (a: readonly ReviewPath[] | undefined, b: readonly ReviewPath[] | undefined) => {
+  if (!a && !b) return true
+  if (!a || !b) return false
+  if (a.length !== b.length) return false
+  return a.every((path, idx) => pathEqual(path, b[idx]))
+}
 export type AvatarColorKey = (typeof AVATAR_COLOR_KEYS)[number]
 
 export function getAvatarColors(key?: string) {
@@ -38,7 +59,7 @@ type SessionTabs = {
 
 type SessionView = {
   scroll: Record<string, SessionScroll>
-  reviewOpen?: string[]
+  reviewOpen?: ReviewPath[]
   pendingMessage?: string
   pendingMessageAt?: number
 }
@@ -49,22 +70,22 @@ type TabHandoff = {
   at: number
 }
 
-export type LocalProject = Partial<Project> & { worktree: string; expanded: boolean }
+export type LocalProject = Partial<Project> & { worktree: WorkspacePath; expanded: boolean }
 
 export type ReviewDiffStyle = "unified" | "split"
 
 export function ensureSessionKey(key: string, touch: (key: string) => void, seed: (key: string) => void) {
-  touch(key)
-  seed(key)
-  return key
+  const next = normalizeSessionKey(key)
+  touch(next)
+  seed(next)
+  return next
 }
 
-export function createSessionKeyReader(sessionKey: string | Accessor<string>, ensure: (key: string) => void) {
+export function createSessionKeyReader(sessionKey: string | Accessor<string>, ensure: (key: string) => string) {
   const key = typeof sessionKey === "function" ? sessionKey : () => sessionKey
   return () => {
     const value = key()
-    ensure(value)
-    return value
+    return ensure(value)
   }
 }
 
@@ -98,21 +119,12 @@ function nextSessionTabsForOpen(current: SessionTabs | undefined, tab: string):
   return { all, active: tab }
 }
 
-const sessionPath = (key: string) => {
-  const dir = key.split("/")[0]
-  if (!dir) return
-  const root = decode64(dir)
-  if (!root) return
-  return createPathHelpers(() => root)
-}
-
-const normalizeSessionTab = (path: ReturnType<typeof createPathHelpers> | undefined, tab: string) => {
-  if (!tab.startsWith("file://")) return tab
+const normalizeSessionTab = (path: ReturnType<typeof sessionPathHelpers>, tab: string) => {
   if (!path) return tab
-  return path.tab(tab)
+  return path.normalizeTab(tab)
 }
 
-const normalizeSessionTabList = (path: ReturnType<typeof createPathHelpers> | undefined, all: string[]) => {
+const normalizeSessionTabList = (path: ReturnType<typeof sessionPathHelpers>, all: string[]) => {
   const seen = new Set<string>()
   return all.flatMap((tab) => {
     const value = normalizeSessionTab(path, tab)
@@ -122,8 +134,8 @@ const normalizeSessionTabList = (path: ReturnType<typeof createPathHelpers> | un
   })
 }
 
-const normalizeStoredSessionTabs = (key: string, tabs: SessionTabs) => {
-  const path = sessionPath(key)
+export const normalizeStoredSessionTabs = (key: string, tabs: SessionTabs) => {
+  const path = sessionPathHelpers(key)
   return {
     all: normalizeSessionTabList(path, tabs.all),
     active: tabs.active ? normalizeSessionTab(path, tabs.active) : tabs.active,
@@ -141,20 +153,10 @@ export const { use: useLayout, provider: LayoutProvider } = createSimpleContext(
     const isRecord = (value: unknown): value is Record<string, unknown> =>
       typeof value === "object" && value !== null && !Array.isArray(value)
 
-    const migrate = (value: unknown) => {
+    const migrate = (input: unknown) => {
+      const value = migrateLayoutPaths(input)
       if (!isRecord(value)) return value
 
-      const sidebar = value.sidebar
-      const migratedSidebar = (() => {
-        if (!isRecord(sidebar)) return sidebar
-        if (typeof sidebar.workspaces !== "boolean") return sidebar
-        return {
-          ...sidebar,
-          workspaces: {},
-          workspacesDefault: sidebar.workspaces,
-        }
-      })()
-
       const review = value.review
       const fileTree = value.fileTree
       const migratedFileTree = (() => {
@@ -206,18 +208,12 @@ export const { use: useLayout, provider: LayoutProvider } = createSimpleContext(
         return next
       })()
 
-      if (
-        migratedSidebar === sidebar &&
-        migratedReview === review &&
-        migratedFileTree === fileTree &&
-        migratedSessionTabs === sessionTabs
-      ) {
+      if (migratedReview === review && migratedFileTree === fileTree && migratedSessionTabs === sessionTabs) {
         return value
       }
 
       return {
         ...value,
-        sidebar: migratedSidebar,
         review: migratedReview,
         fileTree: migratedFileTree,
         sessionTabs: migratedSessionTabs,
@@ -231,7 +227,7 @@ export const { use: useLayout, provider: LayoutProvider } = createSimpleContext(
         sidebar: {
           opened: false,
           width: DEFAULT_PANEL_WIDTH,
-          workspaces: {} as Record<string, boolean>,
+          workspaces: {} as Record<WorkspaceKey, boolean>,
           workspacesDefault: false,
         },
         terminal: {
@@ -277,17 +273,18 @@ export const { use: useLayout, provider: LayoutProvider } = createSimpleContext(
 
     const dropSessionState = (keys: string[]) => {
       for (const key of keys) {
-        const parts = key.split("/")
-        const dir = parts[0]
-        const session = parts[1]
+        const parts = sessionParts(key)
+        const dir = parts.directory
+        const session = parts.id
         if (!dir) continue
 
         for (const entry of SESSION_STATE_KEYS) {
           const target = session ? Persist.session(dir, session, entry.key) : Persist.workspace(dir, entry.key)
           void removePersisted(target, platform)
 
-          const legacyKey = `${dir}/${entry.legacy}${session ? "/" + session : ""}.${entry.version}`
-          void removePersisted({ key: legacyKey }, platform)
+          for (const legacy of Persist.legacyScoped(dir, session, entry.legacy, entry.version)) {
+            void removePersisted({ key: legacy }, platform)
+          }
         }
       }
     }
@@ -384,12 +381,12 @@ export const { use: useLayout, provider: LayoutProvider } = createSimpleContext(
       return available[Math.floor(Math.random() * available.length)]
     }
 
-    function enrich(project: { worktree: string; expanded: boolean }) {
+    function enrich(project: { worktree: WorkspacePath; expanded: boolean }) {
       const [childStore] = globalSync.child(project.worktree, { bootstrap: false })
       const projectID = childStore.project
       const metadata = projectID
         ? globalSync.data.project.find((x) => x.id === projectID)
-        : globalSync.data.project.find((x) => x.worktree === project.worktree)
+        : globalSync.data.project.find((x) => pathEqual(x.worktree, project.worktree))
 
       const local = childStore.projectMeta
       const localOverride =
@@ -425,32 +422,34 @@ export const { use: useLayout, provider: LayoutProvider } = createSimpleContext(
     }
 
     const roots = createMemo(() => {
-      const map = new Map<string, string>()
+      const map = new Map<WorkspaceKey, WorkspacePath>()
       for (const project of globalSync.data.project) {
         const sandboxes = project.sandboxes ?? []
         for (const sandbox of sandboxes) {
-          map.set(sandbox, project.worktree)
+          map.set(workspacePathKey(sandbox), project.worktree)
         }
       }
       return map
     })
 
-    const rootFor = (directory: string) => {
+    const rootFor = (directory: WorkspacePath) => {
       const map = roots()
       if (map.size === 0) return directory
 
-      const visited = new Set<string>()
+      const visited = new Set<WorkspaceKey>()
       const chain = [directory]
 
       while (chain.length) {
         const current = chain[chain.length - 1]
         if (!current) return directory
 
-        const next = map.get(current)
+        const key = workspacePathKey(current)
+        const next = map.get(key)
         if (!next) return current
 
-        if (visited.has(next)) return directory
-        visited.add(next)
+        const id = workspacePathKey(next)
+        if (visited.has(id)) return directory
+        visited.add(id)
         chain.push(next)
       }
 
@@ -459,18 +458,19 @@ export const { use: useLayout, provider: LayoutProvider } = createSimpleContext(
 
     createEffect(() => {
       const projects = server.projects.list()
-      const seen = new Set(projects.map((project) => project.worktree))
+      const seen = new Set(projects.map((project) => workspacePathKey(project.worktree)))
 
       batch(() => {
         for (const project of projects) {
           const root = rootFor(project.worktree)
-          if (root === project.worktree) continue
+          if (pathEqual(root, project.worktree)) continue
 
           server.projects.close(project.worktree)
 
-          if (!seen.has(root)) {
+          const key = workspacePathKey(root)
+          if (!seen.has(key)) {
             server.projects.open(root)
-            seen.add(root)
+            seen.add(key)
           }
 
           if (project.expanded) server.projects.expand(root)
@@ -556,7 +556,7 @@ export const { use: useLayout, provider: LayoutProvider } = createSimpleContext(
       handoff: {
         tabs: createMemo(() => store.handoff?.tabs),
         setTabs(dir: string, id: string) {
-          setStore("handoff", "tabs", { dir, id, at: Date.now() })
+          setStore("handoff", "tabs", { dir: sessionDirKey(dir), id, at: Date.now() })
         },
         clearTabs() {
           if (!store.handoff?.tabs) return
@@ -565,22 +565,22 @@ export const { use: useLayout, provider: LayoutProvider } = createSimpleContext(
       },
       projects: {
         list,
-        open(directory: string) {
+        open(directory: WorkspacePath) {
           const root = rootFor(directory)
-          if (server.projects.list().find((x) => x.worktree === root)) return
+          if (server.projects.list().some((x) => pathEqual(x.worktree, root))) return
           globalSync.project.loadSessions(root)
           server.projects.open(root)
         },
-        close(directory: string) {
+        close(directory: WorkspacePath) {
           server.projects.close(directory)
         },
-        expand(directory: string) {
+        expand(directory: WorkspacePath) {
           server.projects.expand(directory)
         },
-        collapse(directory: string) {
+        collapse(directory: WorkspacePath) {
           server.projects.collapse(directory)
         },
-        move(directory: string, toIndex: number) {
+        move(directory: WorkspacePath, toIndex: number) {
           server.projects.move(directory, toIndex)
         },
       },
@@ -599,15 +599,16 @@ export const { use: useLayout, provider: LayoutProvider } = createSimpleContext(
         resize(width: number) {
           setStore("sidebar", "width", width)
         },
-        workspaces(directory: string) {
-          return () => store.sidebar.workspaces[directory] ?? store.sidebar.workspacesDefault ?? false
+        workspaces(directory: WorkspacePath) {
+          return () => store.sidebar.workspaces[workspacePathKey(directory)] ?? store.sidebar.workspacesDefault ?? false
         },
-        setWorkspaces(directory: string, value: boolean) {
-          setStore("sidebar", "workspaces", directory, value)
+        setWorkspaces(directory: WorkspacePath, value: boolean) {
+          setStore("sidebar", "workspaces", workspacePathKey(directory), value)
         },
-        toggleWorkspaces(directory: string) {
-          const current = store.sidebar.workspaces[directory] ?? store.sidebar.workspacesDefault ?? false
-          setStore("sidebar", "workspaces", directory, !current)
+        toggleWorkspaces(directory: WorkspacePath) {
+          const key = workspacePathKey(directory)
+          const current = store.sidebar.workspaces[key] ?? store.sidebar.workspacesDefault ?? false
+          setStore("sidebar", "workspaces", key, !current)
         },
       },
       terminal: {
@@ -617,67 +618,39 @@ export const { use: useLayout, provider: LayoutProvider } = createSimpleContext(
         },
       },
       review: {
-        diffStyle: createMemo(() => store.review?.diffStyle ?? "split"),
+        diffStyle: createMemo(() => store.review.diffStyle),
         setDiffStyle(diffStyle: ReviewDiffStyle) {
-          if (!store.review) {
-            setStore("review", { diffStyle, panelOpened: true })
-            return
-          }
           setStore("review", "diffStyle", diffStyle)
         },
       },
       fileTree: {
-        opened: createMemo(() => store.fileTree?.opened ?? true),
-        width: createMemo(() => store.fileTree?.width ?? DEFAULT_PANEL_WIDTH),
-        tab: createMemo(() => store.fileTree?.tab ?? "changes"),
+        opened: createMemo(() => store.fileTree.opened),
+        width: createMemo(() => store.fileTree.width),
+        tab: createMemo(() => store.fileTree.tab),
         setTab(tab: "changes" | "all") {
-          if (!store.fileTree) {
-            setStore("fileTree", { opened: true, width: DEFAULT_PANEL_WIDTH, tab })
-            return
-          }
           setStore("fileTree", "tab", tab)
         },
         open() {
-          if (!store.fileTree) {
-            setStore("fileTree", { opened: true, width: DEFAULT_PANEL_WIDTH, tab: "changes" })
-            return
-          }
           setStore("fileTree", "opened", true)
         },
         close() {
-          if (!store.fileTree) {
-            setStore("fileTree", { opened: false, width: DEFAULT_PANEL_WIDTH, tab: "changes" })
-            return
-          }
           setStore("fileTree", "opened", false)
         },
         toggle() {
-          if (!store.fileTree) {
-            setStore("fileTree", { opened: true, width: DEFAULT_PANEL_WIDTH, tab: "changes" })
-            return
-          }
           setStore("fileTree", "opened", (x) => !x)
         },
         resize(width: number) {
-          if (!store.fileTree) {
-            setStore("fileTree", { opened: true, width, tab: "changes" })
-            return
-          }
           setStore("fileTree", "width", width)
         },
       },
       session: {
-        width: createMemo(() => store.session?.width ?? DEFAULT_SESSION_WIDTH),
+        width: createMemo(() => store.session.width),
         resize(width: number) {
-          if (!store.session) {
-            setStore("session", { width })
-            return
-          }
           setStore("session", "width", width)
         },
       },
       mobileSidebar: {
-        opened: createMemo(() => store.mobileSidebar?.opened ?? false),
+        opened: createMemo(() => store.mobileSidebar.opened),
         show() {
           setStore("mobileSidebar", "opened", true)
         },
@@ -690,22 +663,23 @@ export const { use: useLayout, provider: LayoutProvider } = createSimpleContext(
       },
       pendingMessage: {
         set(sessionKey: string, messageID: string) {
+          const key = normalizeSessionKey(sessionKey)
           const at = Date.now()
-          touch(sessionKey)
-          const current = store.sessionView[sessionKey]
+          touch(key)
+          const current = store.sessionView[key]
           if (!current) {
-            setStore("sessionView", sessionKey, {
+            setStore("sessionView", key, {
               scroll: {},
               pendingMessage: messageID,
               pendingMessageAt: at,
             })
-            prune(usage.active ?? sessionKey)
+            prune(usage.active ?? key)
             return
           }
 
           setStore(
             "sessionView",
-            sessionKey,
+            key,
             produce((draft) => {
               draft.pendingMessage = messageID
               draft.pendingMessageAt = at
@@ -713,14 +687,15 @@ export const { use: useLayout, provider: LayoutProvider } = createSimpleContext(
           )
         },
         consume(sessionKey: string) {
-          const current = store.sessionView[sessionKey]
+          const key = normalizeSessionKey(sessionKey)
+          const current = store.sessionView[key]
           const message = current?.pendingMessage
           const at = current?.pendingMessageAt
           if (!message || !at) return
 
           setStore(
             "sessionView",
-            sessionKey,
+            key,
             produce((draft) => {
               delete draft.pendingMessage
               delete draft.pendingMessageAt
@@ -734,30 +709,16 @@ export const { use: useLayout, provider: LayoutProvider } = createSimpleContext(
       view(sessionKey: string | Accessor<string>) {
         const key = createSessionKeyReader(sessionKey, ensureKey)
         const s = createMemo(() => store.sessionView[key()] ?? { scroll: {} })
-        const terminalOpened = createMemo(() => store.terminal?.opened ?? false)
-        const reviewPanelOpened = createMemo(() => store.review?.panelOpened ?? true)
+        const terminalOpened = createMemo(() => store.terminal.opened)
+        const reviewPanelOpened = createMemo(() => store.review.panelOpened)
 
         function setTerminalOpened(next: boolean) {
-          const current = store.terminal
-          if (!current) {
-            setStore("terminal", { height: DEFAULT_TERMINAL_HEIGHT, opened: next })
-            return
-          }
-
-          const value = current.opened ?? false
-          if (value === next) return
+          if (store.terminal.opened === next) return
           setStore("terminal", "opened", next)
         }
 
         function setReviewPanelOpened(next: boolean) {
-          const current = store.review
-          if (!current) {
-            setStore("review", { diffStyle: "split" as ReviewDiffStyle, panelOpened: next })
-            return
-          }
-
-          const value = current.panelOpened ?? true
-          if (value === next) return
+          if (store.review.panelOpened === next) return
           setStore("review", "panelOpened", next)
         }
 
@@ -793,10 +754,10 @@ export const { use: useLayout, provider: LayoutProvider } = createSimpleContext(
             },
           },
           review: {
-            open: createMemo(() => s().reviewOpen ?? []),
-            setOpen(open: string[]) {
+            open: createMemo(() => reviewPaths(s().reviewOpen ?? [])),
+            setOpen(open: ReviewPath[]) {
               const session = key()
-              const next = Array.from(new Set(open))
+              const next = reviewPaths(open)
               const current = store.sessionView[session]
               if (!current) {
                 setStore("sessionView", session, {
@@ -806,10 +767,10 @@ export const { use: useLayout, provider: LayoutProvider } = createSimpleContext(
                 return
               }
 
-              if (same(current.reviewOpen, next)) return
+              if (sameReviewPaths(current.reviewOpen, next)) return
               setStore("sessionView", session, "reviewOpen", next)
             },
-            openPath(path: string) {
+            openPath(path: ReviewPath) {
               const session = key()
               const current = store.sessionView[session]
               if (!current) {
@@ -825,15 +786,21 @@ export const { use: useLayout, provider: LayoutProvider } = createSimpleContext(
                 return
               }
 
-              if (current.reviewOpen.includes(path)) return
+              const index = current.reviewOpen.findIndex((item) => pathEqual(item, path))
+              if (index !== -1) {
+                if (current.reviewOpen[index] === path) return
+                setStore("sessionView", session, "reviewOpen", index, path)
+                return
+              }
+
               setStore("sessionView", session, "reviewOpen", current.reviewOpen.length, path)
             },
-            closePath(path: string) {
+            closePath(path: ReviewPath) {
               const session = key()
               const current = store.sessionView[session]?.reviewOpen
               if (!current) return
 
-              const index = current.indexOf(path)
+              const index = current.findIndex((item) => pathEqual(item, path))
               if (index === -1) return
               setStore(
                 "sessionView",
@@ -845,10 +812,10 @@ export const { use: useLayout, provider: LayoutProvider } = createSimpleContext(
                 }),
               )
             },
-            togglePath(path: string) {
+            togglePath(path: ReviewPath) {
               const session = key()
               const current = store.sessionView[session]?.reviewOpen
-              if (!current || !current.includes(path)) {
+              if (!current || !current.some((item) => pathEqual(item, path))) {
                 this.openPath(path)
                 return
               }
@@ -860,7 +827,7 @@ export const { use: useLayout, provider: LayoutProvider } = createSimpleContext(
       },
       tabs(sessionKey: string | Accessor<string>) {
         const key = createSessionKeyReader(sessionKey, ensureKey)
-        const path = createMemo(() => sessionPath(key()))
+        const path = createMemo(() => sessionPathHelpers(key()))
         const tabs = createMemo(() => store.sessionTabs[key()] ?? { all: [] })
         const normalize = (tab: string) => normalizeSessionTab(path(), tab)
         const normalizeAll = (all: string[]) => normalizeSessionTabList(path(), all)
diff --git a/packages/app/src/context/local.tsx b/packages/app/src/context/local.tsx
index 76d337c82b42..52e17c4f29a6 100644
--- a/packages/app/src/context/local.tsx
+++ b/packages/app/src/context/local.tsx
@@ -3,6 +3,7 @@ import { base64Encode } from "@opencode-ai/util/encode"
 import { useParams } from "@solidjs/router"
 import { batch, createEffect, createMemo, onCleanup } from "solid-js"
 import { createStore } from "solid-js/store"
+import { workspacePathKey } from "@/context/file/path"
 import { useModels } from "@/context/models"
 import { useProviders } from "@/hooks/use-providers"
 import { modelEnabled, modelProbe } from "@/testing/model-selection"
@@ -26,7 +27,7 @@ type Saved = {
 const WORKSPACE_KEY = "__workspace__"
 const handoff = new Map<string, State>()
 
-const handoffKey = (dir: string, id: string) => `${dir}\n${id}`
+const handoffKey = (dir: string, id: string) => `${workspacePathKey(dir)}\n${id}`
 
 const migrate = (value: unknown) => {
   if (!value || typeof value !== "object") return { session: {} }
diff --git a/packages/app/src/context/notification-state.ts b/packages/app/src/context/notification-state.ts
new file mode 100644
index 000000000000..5ce2251d0a39
--- /dev/null
+++ b/packages/app/src/context/notification-state.ts
@@ -0,0 +1,97 @@
+import { EventSessionError } from "@opencode-ai/sdk/v2"
+import { type WorkspacePath, workspacePathKey } from "@/context/file/path"
+
+type NotificationBase = {
+  directory?: WorkspacePath
+  session?: string
+  metadata?: unknown
+  time: number
+  viewed: boolean
+}
+
+type TurnCompleteNotification = NotificationBase & {
+  type: "turn-complete"
+}
+
+type ErrorNotification = NotificationBase & {
+  type: "error"
+  error: EventSessionError["properties"]["error"]
+}
+
+export type Notification = TurnCompleteNotification | ErrorNotification
+
+export type NotificationIndex = {
+  session: {
+    all: Record<string, Notification[]>
+    unseen: Record<string, Notification[]>
+    unseenCount: Record<string, number>
+    unseenHasError: Record<string, boolean>
+  }
+  project: {
+    all: Record<string, Notification[]>
+    unseen: Record<string, Notification[]>
+    unseenCount: Record<string, number>
+    unseenHasError: Record<string, boolean>
+  }
+}
+
+function createNotificationIndex(): NotificationIndex {
+  return {
+    session: {
+      all: {},
+      unseen: {},
+      unseenCount: {},
+      unseenHasError: {},
+    },
+    project: {
+      all: {},
+      unseen: {},
+      unseenCount: {},
+      unseenHasError: {},
+    },
+  }
+}
+
+export const projectKey = (directory: WorkspacePath) => workspacePathKey(directory)
+
+export function normalizeNotification(notification: Notification): Notification {
+  return notification
+}
+
+export function migrateNotifications(value: unknown) {
+  if (!value || typeof value !== "object") return { list: [] as Notification[] }
+  const list = Array.isArray((value as { list?: unknown }).list) ? (value as { list: Notification[] }).list : []
+  return { list: list.map(normalizeNotification) }
+}
+
+export function buildNotificationIndex(list: Notification[]) {
+  const index = createNotificationIndex()
+
+  list.forEach((item) => {
+    const notification = normalizeNotification(item)
+    if (notification.session) {
+      const all = index.session.all[notification.session] ?? []
+      index.session.all[notification.session] = [...all, notification]
+      if (!notification.viewed) {
+        const unseen = index.session.unseen[notification.session] ?? []
+        index.session.unseen[notification.session] = [...unseen, notification]
+        index.session.unseenCount[notification.session] = unseen.length + 1
+        if (notification.type === "error") index.session.unseenHasError[notification.session] = true
+      }
+    }
+
+    if (notification.directory) {
+      const key = projectKey(notification.directory)
+      const all = index.project.all[key] ?? []
+      index.project.all[key] = [...all, notification]
+      if (!notification.viewed) {
+        const unseen = index.project.unseen[key] ?? []
+        index.project.unseen[key] = [...unseen, notification]
+        index.project.unseenCount[key] = unseen.length + 1
+        if (notification.type === "error") index.project.unseenHasError[key] = true
+      }
+    }
+  })
+
+  return index
+}
diff --git a/packages/app/src/context/notification.test.ts b/packages/app/src/context/notification.test.ts
new file mode 100644
index 000000000000..13874ccadd6c
--- /dev/null
+++ b/packages/app/src/context/notification.test.ts
@@ -0,0 +1,30 @@
+import { describe, expect, test } from "bun:test"
+import { buildNotificationIndex, migrateNotifications, type Notification } from "./notification-state"
+
+describe("notification directory normalization", () => {
+  test("indexes equivalent project paths together", () => {
+    const list: Notification[] = [
+      { type: "turn-complete", directory: "C:/Repo", session: "ses_1", time: 1, viewed: false },
+      {
+        type: "error",
+        directory: "c:\\repo\\",
+        session: "ses_2",
+        time: 2,
+        viewed: false,
+        error: { name: "UnknownError", data: { message: "boom" } },
+      },
+    ]
+
+    const index = buildNotificationIndex(list)
+
+    expect(index.project.unseenCount["c:/repo"]).toBe(2)
+    expect(index.project.unseenHasError["c:/repo"]).toBe(true)
+    expect(index.project.all["c:/repo"].map((item) => item.directory)).toEqual(["C:/Repo", "c:\\repo\\"])
+  })
+
+  test("preserves stored notification directory values during migration", () => {
+    expect(migrateNotifications({ list: [{ type: "turn-complete", directory: "C:\\Repo\\", time: 1, viewed: true }] })).toEqual({
+      list: [{ type: "turn-complete", directory: "C:\\Repo\\", time: 1, viewed: true }],
+    })
+  })
+})
diff --git a/packages/app/src/context/notification.tsx b/packages/app/src/context/notification.tsx
index 04bc2fdaaaf3..bbf15b8146de 100644
--- a/packages/app/src/context/notification.tsx
+++ b/packages/app/src/context/notification.tsx
@@ -2,6 +2,7 @@ import { createStore, reconcile } from "solid-js/store"
 import { batch, createEffect, createMemo, onCleanup } from "solid-js"
 import { useParams } from "@solidjs/router"
 import { createSimpleContext } from "@opencode-ai/ui/context"
+import { pathEqual } from "@opencode-ai/util/path"
 import { useGlobalSDK } from "./global-sdk"
 import { useGlobalSync } from "./global-sync"
 import { usePlatform } from "@/context/platform"
@@ -13,40 +14,15 @@ import { decode64 } from "@/utils/base64"
 import { EventSessionError } from "@opencode-ai/sdk/v2"
 import { Persist, persisted } from "@/utils/persist"
 import { playSound, soundSrc } from "@/utils/sound"
-
-type NotificationBase = {
-  directory?: string
-  session?: string
-  metadata?: unknown
-  time: number
-  viewed: boolean
-}
-
-type TurnCompleteNotification = NotificationBase & {
-  type: "turn-complete"
-}
-
-type ErrorNotification = NotificationBase & {
-  type: "error"
-  error: EventSessionError["properties"]["error"]
-}
-
-export type Notification = TurnCompleteNotification | ErrorNotification
-
-type NotificationIndex = {
-  session: {
-    all: Record<string, Notification[]>
-    unseen: Record<string, Notification[]>
-    unseenCount: Record<string, number>
-    unseenHasError: Record<string, boolean>
-  }
-  project: {
-    all: Record<string, Notification[]>
-    unseen: Record<string, Notification[]>
-    unseenCount: Record<string, number>
-    unseenHasError: Record<string, boolean>
-  }
-}
+import { type WorkspacePath } from "@/context/file/path"
+import {
+  buildNotificationIndex,
+  migrateNotifications,
+  normalizeNotification,
+  projectKey,
+  type Notification,
+  type NotificationIndex,
+} from "./notification-state"
 
 const MAX_NOTIFICATIONS = 500
 const NOTIFICATION_TTL_MS = 1000 * 60 * 60 * 24 * 30
@@ -58,53 +34,6 @@ function pruneNotifications(list: Notification[]) {
   return pruned.slice(pruned.length - MAX_NOTIFICATIONS)
 }
 
-function createNotificationIndex(): NotificationIndex {
-  return {
-    session: {
-      all: {},
-      unseen: {},
-      unseenCount: {},
-      unseenHasError: {},
-    },
-    project: {
-      all: {},
-      unseen: {},
-      unseenCount: {},
-      unseenHasError: {},
-    },
-  }
-}
-
-function buildNotificationIndex(list: Notification[]) {
-  const index = createNotificationIndex()
-
-  list.forEach((notification) => {
-    if (notification.session) {
-      const all = index.session.all[notification.session] ?? []
-      index.session.all[notification.session] = [...all, notification]
-      if (!notification.viewed) {
-        const unseen = index.session.unseen[notification.session] ?? []
-        index.session.unseen[notification.session] = [...unseen, notification]
-        index.session.unseenCount[notification.session] = unseen.length + 1
-        if (notification.type === "error") index.session.unseenHasError[notification.session] = true
-      }
-    }
-
-    if (notification.directory) {
-      const all = index.project.all[notification.directory] ?? []
-      index.project.all[notification.directory] = [...all, notification]
-      if (!notification.viewed) {
-        const unseen = index.project.unseen[notification.directory] ?? []
-        index.project.unseen[notification.directory] = [...unseen, notification]
-        index.project.unseenCount[notification.directory] = unseen.length + 1
-        if (notification.type === "error") index.project.unseenHasError[notification.directory] = true
-      }
-    }
-  })
-
-  return index
-}
-
 export const { use: useNotification, provider: NotificationProvider } = createSimpleContext({
   name: "Notification",
   init: () => {
@@ -117,14 +46,12 @@ export const { use: useNotification, provider: NotificationProvider } = createSi
 
     const empty: Notification[] = []
 
-    const currentDirectory = createMemo(() => {
-      return decode64(params.dir)
-    })
+    const currentDirectory = createMemo(() => decode64(params.dir))
 
     const currentSession = createMemo(() => params.id)
 
     const [store, setStore, _, ready] = persisted(
-      Persist.global("notification", ["notification.v1"]),
+      { ...Persist.global("notification", ["notification.v1"]), migrate: migrateNotifications },
       createStore({
         list: [] as Notification[],
       }),
@@ -145,6 +72,7 @@ export const { use: useNotification, provider: NotificationProvider } = createSi
     }
 
     const appendToIndex = (notification: Notification) => {
+      notification = normalizeNotification(notification)
       if (notification.session) {
         setIndex("session", "all", notification.session, (all = []) => [...all, notification])
         if (!notification.viewed) {
@@ -155,16 +83,18 @@ export const { use: useNotification, provider: NotificationProvider } = createSi
       }
 
       if (notification.directory) {
-        setIndex("project", "all", notification.directory, (all = []) => [...all, notification])
+        const key = projectKey(notification.directory)
+        setIndex("project", "all", key, (all = []) => [...all, notification])
         if (!notification.viewed) {
-          setIndex("project", "unseen", notification.directory, (unseen = []) => [...unseen, notification])
-          setIndex("project", "unseenCount", notification.directory, (count = 0) => count + 1)
-          if (notification.type === "error") setIndex("project", "unseenHasError", notification.directory, true)
+          setIndex("project", "unseen", key, (unseen = []) => [...unseen, notification])
+          setIndex("project", "unseenCount", key, (count = 0) => count + 1)
+          if (notification.type === "error") setIndex("project", "unseenHasError", key, true)
         }
       }
     }
 
     const removeFromIndex = (notification: Notification) => {
+      notification = normalizeNotification(notification)
       if (notification.session) {
         setIndex("session", "all", notification.session, (all = []) => all.filter((n) => n !== notification))
         if (!notification.viewed) {
@@ -174,10 +104,11 @@ export const { use: useNotification, provider: NotificationProvider } = createSi
       }
 
       if (notification.directory) {
-        setIndex("project", "all", notification.directory, (all = []) => all.filter((n) => n !== notification))
+        const key = projectKey(notification.directory)
+        setIndex("project", "all", key, (all = []) => all.filter((n) => n !== notification))
         if (!notification.viewed) {
-          const unseen = (index.project.unseen[notification.directory] ?? empty).filter((n) => n !== notification)
-          updateUnseen("project", notification.directory, unseen)
+          const unseen = (index.project.unseen[key] ?? empty).filter((n) => n !== notification)
+          updateUnseen("project", key, unseen)
         }
       }
     }
@@ -194,6 +125,7 @@ export const { use: useNotification, provider: NotificationProvider } = createSi
     })
 
     const append = (notification: Notification) => {
+      notification = normalizeNotification(notification)
       const list = pruneNotifications([...store.list, notification])
       const keep = new Set(list)
       const removed = store.list.filter((n) => !keep.has(n))
@@ -205,7 +137,7 @@ export const { use: useNotification, provider: NotificationProvider } = createSi
       })
     }
 
-    const lookup = async (directory: string, sessionID?: string) => {
+    const lookup = async (directory: WorkspacePath, sessionID?: string) => {
       if (!sessionID) return undefined
       const [syncStore] = globalSync.child(directory, { bootstrap: false })
       const match = Binary.search(syncStore.session, sessionID, (s) => s.id)
@@ -216,17 +148,17 @@ export const { use: useNotification, provider: NotificationProvider } = createSi
         .catch(() => undefined)
     }
 
-    const viewedInCurrentSession = (directory: string, sessionID?: string) => {
+    const viewedInCurrentSession = (directory: WorkspacePath, sessionID?: string) => {
       const activeDirectory = currentDirectory()
       const activeSession = currentSession()
       if (!activeDirectory) return false
       if (!activeSession) return false
       if (!sessionID) return false
-      if (directory !== activeDirectory) return false
+      if (!pathEqual(directory, activeDirectory)) return false
       return sessionID === activeSession
     }
 
-    const handleSessionIdle = (directory: string, event: { properties: { sessionID?: string } }, time: number) => {
+    const handleSessionIdle = (directory: WorkspacePath, event: { properties: { sessionID?: string } }, time: number) => {
       const sessionID = event.properties.sessionID
       void lookup(directory, sessionID).then((session) => {
         if (meta.disposed) return
@@ -253,7 +185,7 @@ export const { use: useNotification, provider: NotificationProvider } = createSi
     }
 
     const handleSessionError = (
-      directory: string,
+      directory: WorkspacePath,
       event: { properties: { sessionID?: string; error?: EventSessionError["properties"]["error"] } },
       time: number,
     ) => {
@@ -328,40 +260,42 @@ export const { use: useNotification, provider: NotificationProvider } = createSi
             setStore("list", (n) => n.session === session && !n.viewed, "viewed", true)
             updateUnseen("session", session, [])
             projects.forEach((directory) => {
-              const next = (index.project.unseen[directory] ?? empty).filter(
+              const key = projectKey(directory)
+              const next = (index.project.unseen[key] ?? empty).filter(
                 (notification) => notification.session !== session,
               )
-              updateUnseen("project", directory, next)
+              updateUnseen("project", key, next)
             })
           })
         },
       },
       project: {
-        all(directory: string) {
-          return index.project.all[directory] ?? empty
+        all(directory: WorkspacePath) {
+          return index.project.all[projectKey(directory)] ?? empty
         },
-        unseen(directory: string) {
-          return index.project.unseen[directory] ?? empty
+        unseen(directory: WorkspacePath) {
+          return index.project.unseen[projectKey(directory)] ?? empty
         },
-        unseenCount(directory: string) {
-          return index.project.unseenCount[directory] ?? 0
+        unseenCount(directory: WorkspacePath) {
+          return index.project.unseenCount[projectKey(directory)] ?? 0
         },
-        unseenHasError(directory: string) {
-          return index.project.unseenHasError[directory] ?? false
+        unseenHasError(directory: WorkspacePath) {
+          return index.project.unseenHasError[projectKey(directory)] ?? false
         },
-        markViewed(directory: string) {
-          const unseen = index.project.unseen[directory] ?? empty
+        markViewed(directory: WorkspacePath) {
+          const key = projectKey(directory)
+          const unseen = index.project.unseen[key] ?? empty
           if (!unseen.length) return
 
           const sessions = [
             ...new Set(unseen.flatMap((notification) => (notification.session ? [notification.session] : []))),
           ]
           batch(() => {
-            setStore("list", (n) => n.directory === directory && !n.viewed, "viewed", true)
-            updateUnseen("project", directory, [])
+            setStore("list", (n) => !!n.directory && pathEqual(n.directory, directory) && !n.viewed, "viewed", true)
+            updateUnseen("project", key, [])
             sessions.forEach((session) => {
               const next = (index.session.unseen[session] ?? empty).filter(
-                (notification) => notification.directory !== directory,
+                (notification) => !notification.directory || !pathEqual(notification.directory, directory),
               )
               updateUnseen("session", session, next)
             })
diff --git a/packages/app/src/context/permission-auto-respond.test.ts b/packages/app/src/context/permission-auto-respond.test.ts
index 755611300554..e60c1b778c40 100644
--- a/packages/app/src/context/permission-auto-respond.test.ts
+++ b/packages/app/src/context/permission-auto-respond.test.ts
@@ -99,4 +99,9 @@ describe("isDirectoryAutoAccepting", () => {
     const autoAccept = { [`${base64Encode(directory)}/*`]: false }
     expect(isDirectoryAutoAccepting(autoAccept, directory)).toBe(false)
   })
+
+  test("accepts legacy and normalized directory variants interchangeably", () => {
+    const autoAccept = { [`${base64Encode("C:/Repo")}/*`]: true }
+    expect(isDirectoryAutoAccepting(autoAccept, "c:\\repo\\")).toBe(true)
+  })
 })
diff --git a/packages/app/src/context/permission-auto-respond.ts b/packages/app/src/context/permission-auto-respond.ts
index b206deedff93..b1eaf2f834f3 100644
--- a/packages/app/src/context/permission-auto-respond.ts
+++ b/packages/app/src/context/permission-auto-respond.ts
@@ -1,23 +1,60 @@
 import { base64Encode } from "@opencode-ai/util/encode"
+import { workspacePathKey } from "@/context/file/path"
+import { decode64 } from "@/utils/base64"
+
+const dir = (directory: string) => workspacePathKey(directory)
 
 export function acceptKey(sessionID: string, directory?: string) {
   if (!directory) return sessionID
-  return `${base64Encode(directory)}/${sessionID}`
+  return `${base64Encode(dir(directory))}/${sessionID}`
 }
 
 export function directoryAcceptKey(directory: string) {
+  return `${base64Encode(dir(directory))}/*`
+}
+
+function legacyDirectoryAcceptKey(directory: string) {
   return `${base64Encode(directory)}/*`
 }
 
+function matches(a: string | undefined, b: string) {
+  return !!a && dir(a) === dir(b)
+}
+
+function legacySessionAccept(autoAccept: Record<string, boolean>, sessionID: string, directory?: string) {
+  if (!directory) return
+  for (const [key, value] of Object.entries(autoAccept)) {
+    if (!key.endsWith(`/${sessionID}`)) continue
+    const idx = key.length - sessionID.length - 1
+    if (idx <= 0) continue
+    if (!matches(decode64(key.slice(0, idx)), directory)) continue
+    return value
+  }
+}
+
+function legacyDirectoryAccept(autoAccept: Record<string, boolean>, directory: string) {
+  for (const [key, value] of Object.entries(autoAccept)) {
+    if (!key.endsWith("/*")) continue
+    if (!matches(decode64(key.slice(0, -2)), directory)) continue
+    return value
+  }
+}
+
 function accepted(autoAccept: Record<string, boolean>, sessionID: string, directory?: string) {
   const key = acceptKey(sessionID, directory)
   const directoryKey = directory ? directoryAcceptKey(directory) : undefined
-  return autoAccept[key] ?? autoAccept[sessionID] ?? (directoryKey ? autoAccept[directoryKey] : undefined)
+  return (
+    autoAccept[key] ??
+    legacySessionAccept(autoAccept, sessionID, directory) ??
+    autoAccept[sessionID] ??
+    (directoryKey ? autoAccept[directoryKey] : undefined) ??
+    (directory ? legacyDirectoryAccept(autoAccept, directory) : undefined)
+  )
 }
 
 export function isDirectoryAutoAccepting(autoAccept: Record<string, boolean>, directory: string) {
   const key = directoryAcceptKey(directory)
-  return autoAccept[key] ?? false
+  return autoAccept[key] ?? legacyDirectoryAccept(autoAccept, directory) ?? false
 }
 
 function sessionLineage(session: { id: string; parentID?: string }[], sessionID: string) {
diff --git a/packages/app/src/context/platform.test.ts b/packages/app/src/context/platform.test.ts
new file mode 100644
index 000000000000..2fb39fb44892
--- /dev/null
+++ b/packages/app/src/context/platform.test.ts
@@ -0,0 +1,33 @@
+import { describe, expect, test } from "bun:test"
+import { clientOS, serverOS, type Platform } from "./platform"
+
+describe("platform helpers", () => {
+  test("prefers server os when available", () => {
+    const platform: Platform = {
+      platform: "desktop",
+      os: "linux",
+      openLink() {},
+      async restart() {},
+      back() {},
+      forward() {},
+      async notify() {},
+    }
+
+    expect(serverOS({ os: "windows" }, platform)).toBe("windows")
+  })
+
+  test("falls back to the client os", () => {
+    const platform: Platform = {
+      platform: "desktop",
+      os: "macos",
+      openLink() {},
+      async restart() {},
+      back() {},
+      forward() {},
+      async notify() {},
+    }
+
+    expect(clientOS(platform)).toBe("macos")
+    expect(serverOS(undefined, platform)).toBe("macos")
+  })
+})
diff --git a/packages/app/src/context/platform.tsx b/packages/app/src/context/platform.tsx
index 3bdc46391b67..a0fc5fbfa07a 100644
--- a/packages/app/src/context/platform.tsx
+++ b/packages/app/src/context/platform.tsx
@@ -3,18 +3,23 @@ import type { AsyncStorage, SyncStorage } from "@solid-primitives/storage"
 import type { Accessor } from "solid-js"
 import { ServerConnection } from "./server"
 
+export type OS = "macos" | "windows" | "linux"
+
 type PickerPaths = string | string[] | null
 type OpenDirectoryPickerOptions = { title?: string; multiple?: boolean }
 type OpenFilePickerOptions = { title?: string; multiple?: boolean; accept?: string[]; extensions?: string[] }
 type SaveFilePickerOptions = { title?: string; defaultPath?: string }
 type UpdateInfo = { updateAvailable: boolean; version?: string }
 
+type KnownOS = OS | "unknown"
+type ServerPath = { os?: OS | null }
+
 export type Platform = {
   /** Platform discriminator */
   platform: "web" | "desktop"
 
   /** Desktop OS (Tauri only) */
-  os?: "macos" | "windows" | "linux"
+  os?: OS
 
   /** App version */
   version?: string
@@ -91,6 +96,20 @@ export type Platform = {
 
 export type DisplayBackend = "auto" | "wayland"
 
+export function clientOS(platform?: Pick<Platform, "platform" | "os">): KnownOS {
+  if (platform?.platform === "desktop" && platform.os) return platform.os
+  if (typeof navigator !== "object") return "unknown"
+  const value = navigator.platform || navigator.userAgent
+  if (/Mac/i.test(value)) return "macos"
+  if (/Win/i.test(value)) return "windows"
+  if (/Linux/i.test(value)) return "linux"
+  return "unknown"
+}
+
+export function serverOS(path?: ServerPath | null, platform?: Pick<Platform, "platform" | "os">): KnownOS {
+  return path?.os ?? clientOS(platform)
+}
+
 export const { use: usePlatform, provider: PlatformProvider } = createSimpleContext({
   name: "Platform",
   init: (props: { value: Platform }) => {
diff --git a/packages/app/src/context/prompt.test.ts b/packages/app/src/context/prompt.test.ts
new file mode 100644
index 000000000000..390d1673a904
--- /dev/null
+++ b/packages/app/src/context/prompt.test.ts
@@ -0,0 +1,56 @@
+import { beforeAll, describe, expect, mock, test } from "bun:test"
+import { createRoot } from "solid-js"
+import type { Prompt } from "./prompt"
+
+let createPromptSessionForTest: typeof import("./prompt").createPromptSessionForTest
+let isPromptEqual: typeof import("./prompt").isPromptEqual
+
+beforeAll(async () => {
+  mock.module("@solidjs/router", () => ({
+    useNavigate: () => () => undefined,
+    useParams: () => ({}),
+  }))
+  mock.module("@opencode-ai/ui/context", () => ({
+    createSimpleContext: () => ({
+      use: () => undefined,
+      provider: () => undefined,
+    }),
+  }))
+  const mod = await import("./prompt")
+  createPromptSessionForTest = mod.createPromptSessionForTest
+  isPromptEqual = mod.isPromptEqual
+})
+
+describe("prompt file path state", () => {
+  test("treats file prompt parts with slash variants as equal", () => {
+    const a: Prompt = [{ type: "file", path: "src\\a.ts", content: "@src/a.ts", start: 0, end: 9 }]
+    const b: Prompt = [{ type: "file", path: "src/a.ts", content: "@src/a.ts", start: 0, end: 9 }]
+    expect(isPromptEqual(a, b)).toBe(true)
+  })
+
+  test("updates and removes comment context items across slash variants", () => {
+    createRoot((dispose) => {
+      const prompt = createPromptSessionForTest({
+        context: {
+          items: [
+            {
+              key: "legacy",
+              type: "file",
+              path: "src\\a.ts",
+              commentID: "c1",
+              comment: "note",
+            },
+          ],
+        },
+      })
+
+      prompt.context.updateComment("src/a.ts", "c1", { comment: "edited" })
+      expect(prompt.context.items()[0]?.comment).toBe("edited")
+
+      prompt.context.removeComment("src\\a.ts", "c1")
+      expect(prompt.context.items()).toEqual([])
+
+      dispose()
+    })
+  })
+})
diff --git a/packages/app/src/context/prompt.tsx b/packages/app/src/context/prompt.tsx
index 831fdbca83d3..a76480a5912e 100644
--- a/packages/app/src/context/prompt.tsx
+++ b/packages/app/src/context/prompt.tsx
@@ -2,9 +2,11 @@ import { createSimpleContext } from "@opencode-ai/ui/context"
 import { checksum } from "@opencode-ai/util/encode"
 import { useParams } from "@solidjs/router"
 import { batch, createMemo, createRoot, getOwner, onCleanup } from "solid-js"
-import { createStore, type SetStoreFunction } from "solid-js/store"
+import { createStore, type SetStoreFunction, type Store } from "solid-js/store"
 import type { FileSelection } from "@/context/file"
+import { filePathEqual, filePathKey, normalizeFilePath, type FilePath } from "@/context/file/path"
 import { Persist, persisted } from "@/utils/persist"
+import { sessionScopeKey } from "@/utils/session-key"
 
 interface PartBase {
   content: string
@@ -18,7 +20,7 @@ export interface TextPart extends PartBase {
 
 export interface FileAttachmentPart extends PartBase {
   type: "file"
-  path: string
+  path: FilePath
   selection?: FileSelection
 }
 
@@ -40,7 +42,7 @@ export type Prompt = ContentPart[]
 
 export type FileContextItem = {
   type: "file"
-  path: string
+  path: FilePath
   selection?: FileSelection
   comment?: string
   commentID?: string
@@ -65,7 +67,7 @@ function isPartEqual(partA: ContentPart, partB: ContentPart) {
     case "text":
       return partB.type === "text" && partA.content === partB.content
     case "file":
-      return partB.type === "file" && partA.path === partB.path && isSelectionEqual(partA.selection, partB.selection)
+      return partB.type === "file" && filePathEqual(partA.path, partB.path) && isSelectionEqual(partA.selection, partB.selection)
     case "agent":
       return partB.type === "agent" && partA.name === partB.name
     case "image":
@@ -101,10 +103,9 @@ function clonePrompt(prompt: Prompt): Prompt {
 }
 
 function contextItemKey(item: ContextItem) {
-  if (item.type !== "file") return item.type
   const start = item.selection?.startLine
   const end = item.selection?.endLine
-  const key = `${item.type}:${item.path}:${start}:${end}`
+  const key = `${item.type}:${filePathKey(item.path)}:${start}:${end}`
 
   if (item.commentID) {
     return `${key}:c=${item.commentID}`
@@ -116,18 +117,51 @@ function contextItemKey(item: ContextItem) {
   return `${key}:c=${digest.slice(0, 8)}`
 }
 
-function isCommentItem(item: ContextItem | (ContextItem & { key: string })) {
-  return item.type === "file" && !!item.comment?.trim()
+function normalizeContextItem(item: ContextItem & { key?: string }) {
+  const path = normalizeFilePath(item.path)
+  const next = { ...item, path }
+  return { ...next, key: contextItemKey(next) }
 }
 
-function createPromptActions(
-  setStore: SetStoreFunction<{
-    prompt: Prompt
-    cursor?: number
+function isContextItem(value: unknown): value is ContextItem & { key?: string } {
+  return (
+    !!value &&
+    typeof value === "object" &&
+    "type" in value &&
+    value.type === "file" &&
+    "path" in value &&
+    typeof value.path === "string"
+  )
+}
+
+function migratePromptStore(value: unknown) {
+  if (!value || typeof value !== "object") return value
+  if (!("context" in value)) return value
+  const context = (value as { context?: { items?: unknown } }).context
+  if (!context || !Array.isArray(context.items)) return value
+  return {
+    ...value,
     context: {
-      items: (ContextItem & { key: string })[]
-    }
-  }>,
+      ...context,
+      items: context.items.filter(isContextItem).map(normalizeContextItem),
+    },
+  }
+}
+
+function isCommentItem(item: ContextItem & { key: string }) {
+  return !!item.comment?.trim()
+}
+
+type PromptStore = {
+  prompt: Prompt
+  cursor?: number
+  context: {
+    items: (ContextItem & { key: string })[]
+  }
+}
+
+function createPromptActions(
+  setStore: SetStoreFunction<PromptStore>,
 ) {
   return {
     set(prompt: Prompt, cursorPosition?: number) {
@@ -146,7 +180,6 @@ function createPromptActions(
   }
 }
 
-const WORKSPACE_KEY = "__workspace__"
 const MAX_PROMPT_SESSIONS = 20
 
 type PromptSession = ReturnType<typeof createPromptSession>
@@ -161,61 +194,43 @@ type PromptCacheEntry = {
   dispose: VoidFunction
 }
 
-function createPromptSession(dir: string, id: string | undefined) {
-  const legacy = `${dir}/prompt${id ? "/" + id : ""}.v2`
-
-  const [store, setStore, _, ready] = persisted(
-    Persist.scoped(dir, id, "prompt", [legacy]),
-    createStore<{
-      prompt: Prompt
-      cursor?: number
-      context: {
-        items: (ContextItem & { key: string })[]
-      }
-    }>({
-      prompt: clonePrompt(DEFAULT_PROMPT),
-      cursor: undefined,
-      context: {
-        items: [],
-      },
-    }),
-  )
-
+function createPromptSessionState(store: Store<PromptStore>, setStore: SetStoreFunction<PromptStore>) {
   const actions = createPromptActions(setStore)
 
   return {
-    ready,
     current: createMemo(() => store.prompt),
     cursor: createMemo(() => store.cursor),
     dirty: createMemo(() => !isPromptEqual(store.prompt, DEFAULT_PROMPT)),
     context: {
       items: createMemo(() => store.context.items),
       add(item: ContextItem) {
-        const key = contextItemKey(item)
+        const next = normalizeContextItem(item)
+        const key = next.key
         if (store.context.items.find((x) => x.key === key)) return
-        setStore("context", "items", (items) => [...items, { key, ...item }])
+        setStore("context", "items", (items) => [...items, next])
       },
       remove(key: string) {
         setStore("context", "items", (items) => items.filter((x) => x.key !== key))
       },
-      removeComment(path: string, commentID: string) {
+      removeComment(path: FilePath, commentID: string) {
+        const file = normalizeFilePath(path)
         setStore("context", "items", (items) =>
-          items.filter((item) => !(item.type === "file" && item.path === path && item.commentID === commentID)),
+          items.filter((item) => !(item.path === file && item.commentID === commentID)),
         )
       },
-      updateComment(path: string, commentID: string, next: Partial<FileContextItem> & { comment?: string }) {
+      updateComment(path: FilePath, commentID: string, next: Partial<FileContextItem> & { comment?: string }) {
+        const file = normalizeFilePath(path)
         setStore("context", "items", (items) =>
           items.map((item) => {
-            if (item.type !== "file" || item.path !== path || item.commentID !== commentID) return item
-            const value = { ...item, ...next }
-            return { ...value, key: contextItemKey(value) }
+            if (item.path !== file || item.commentID !== commentID) return item
+            return normalizeContextItem({ ...item, ...next })
           }),
         )
       },
       replaceComments(items: FileContextItem[]) {
         setStore("context", "items", (current) => [
           ...current.filter((item) => !isCommentItem(item)),
-          ...items.map((item) => ({ ...item, key: contextItemKey(item) })),
+          ...items.map(normalizeContextItem),
         ])
       },
     },
@@ -224,6 +239,52 @@ function createPromptSession(dir: string, id: string | undefined) {
   }
 }
 
+export function createPromptSessionForTest(input?: Partial<PromptStore>) {
+  const [store, setStore] = createStore<PromptStore>({
+    prompt: clonePrompt(input?.prompt ?? DEFAULT_PROMPT),
+    cursor: input?.cursor,
+    context: {
+      items: input?.context?.items?.map(normalizeContextItem) ?? [],
+    },
+  })
+
+  const session = createPromptSessionState(store, setStore)
+
+  return {
+    ...session,
+    current: () => store.prompt,
+    cursor: () => store.cursor,
+    dirty: () => !isPromptEqual(store.prompt, DEFAULT_PROMPT),
+    context: {
+      ...session.context,
+      items: () => store.context.items,
+    },
+  }
+}
+
+function createPromptSession(dir: string, id: string | undefined) {
+  const [store, setStore, _, ready] = persisted(
+    {
+      ...Persist.scoped(dir, id, "prompt", Persist.legacyScoped(dir, id, "prompt", "v2")),
+      migrate: migratePromptStore,
+    },
+    createStore<PromptStore>({
+      prompt: clonePrompt(DEFAULT_PROMPT),
+      cursor: undefined,
+      context: {
+        items: [],
+      },
+    }),
+  )
+
+  const session = createPromptSessionState(store, setStore)
+
+  return {
+    ready,
+    ...session,
+  }
+}
+
 export const { use: usePrompt, provider: PromptProvider } = createSimpleContext({
   name: "Prompt",
   gate: false,
@@ -252,7 +313,7 @@ export const { use: usePrompt, provider: PromptProvider } = createSimpleContext(
 
     const owner = getOwner()
     const load = (dir: string, id: string | undefined) => {
-      const key = `${dir}:${id ?? WORKSPACE_KEY}`
+      const key = sessionScopeKey(dir, id)
       const existing = cache.get(key)
       if (existing) {
         cache.delete(key)
@@ -285,8 +346,8 @@ export const { use: usePrompt, provider: PromptProvider } = createSimpleContext(
         items: () => session().context.items(),
         add: (item: ContextItem) => session().context.add(item),
         remove: (key: string) => session().context.remove(key),
-        removeComment: (path: string, commentID: string) => session().context.removeComment(path, commentID),
-        updateComment: (path: string, commentID: string, next: Partial<FileContextItem> & { comment?: string }) =>
+        removeComment: (path: FilePath, commentID: string) => session().context.removeComment(path, commentID),
+        updateComment: (path: FilePath, commentID: string, next: Partial<FileContextItem> & { comment?: string }) =>
           session().context.updateComment(path, commentID, next),
         replaceComments: (items: FileContextItem[]) => session().context.replaceComments(items),
       },
diff --git a/packages/app/src/context/sdk.tsx b/packages/app/src/context/sdk.tsx
index bc97ea13acc8..bdeefcfc9229 100644
--- a/packages/app/src/context/sdk.tsx
+++ b/packages/app/src/context/sdk.tsx
@@ -1,6 +1,7 @@
 import type { Event } from "@opencode-ai/sdk/v2/client"
 import { createSimpleContext } from "@opencode-ai/ui/context"
 import { createGlobalEmitter } from "@solid-primitives/event-bus"
+import { pathEqual } from "@opencode-ai/util/path"
 import { type Accessor, createEffect, createMemo, onCleanup } from "solid-js"
 import { useGlobalSDK } from "./global-sdk"
 
@@ -24,8 +25,9 @@ export const { use: useSDK, provider: SDKProvider } = createSimpleContext({
     const emitter = createGlobalEmitter<SDKEventMap>()
 
     createEffect(() => {
-      const unsub = globalSDK.event.on(directory(), (event) => {
-        emitter.emit(event.type, event)
+      const unsub = globalSDK.event.listen((event) => {
+        if (!pathEqual(event.name, directory())) return
+        emitter.emit(event.details.type, event.details)
       })
       onCleanup(unsub)
     })
diff --git a/packages/app/src/context/server.tsx b/packages/app/src/context/server.tsx
index 1171ca90536f..b6832eb91485 100644
--- a/packages/app/src/context/server.tsx
+++ b/packages/app/src/context/server.tsx
@@ -1,13 +1,32 @@
 import { createSimpleContext } from "@opencode-ai/ui/context"
 import { type Accessor, batch, createEffect, createMemo, onCleanup } from "solid-js"
 import { createStore } from "solid-js/store"
+import { type WorkspacePath, workspacePathKey } from "@/context/file/path"
 import { Persist, persisted } from "@/utils/persist"
+import { migrateServerState } from "@/utils/persist-path"
 import { useCheckServerHealth } from "@/utils/server-health"
 
-type StoredProject = { worktree: string; expanded: boolean }
+type StoredProject = { worktree: WorkspacePath; expanded: boolean }
 type StoredServer = string | ServerConnection.HttpBase | ServerConnection.Http
 const HEALTH_POLL_INTERVAL_MS = 10_000
 
+function projectIndex(list: StoredProject[], worktree: WorkspacePath) {
+  const key = workspacePathKey(worktree)
+  return list.findIndex((item) => workspacePathKey(item.worktree) === key)
+}
+
+function upsertProject(list: StoredProject[], worktree: WorkspacePath) {
+  const index = projectIndex(list, worktree)
+  if (index === -1) return [{ worktree, expanded: true }, ...list]
+
+  const current = list[index]
+  if (current?.worktree === worktree && current.expanded) return list
+
+  const next = [...list]
+  next[index] = { ...current, worktree, expanded: true }
+  return next
+}
+
 export function normalizeServerUrl(input: string) {
   const trimmed = input.trim()
   if (!trimmed) return
@@ -98,11 +117,11 @@ export const { use: useServer, provider: ServerProvider } = createSimpleContext(
     const checkServerHealth = useCheckServerHealth()
 
     const [store, setStore, _, ready] = persisted(
-      Persist.global("server", ["server.v3"]),
+      { ...Persist.global("server", ["server.v3"]), migrate: migrateServerState },
       createStore({
         list: [] as StoredServer[],
         projects: {} as Record<string, StoredProject[]>,
-        lastProject: {} as Record<string, string>,
+        lastProject: {} as Record<string, WorkspacePath>,
       }),
     )
 
@@ -208,6 +227,14 @@ export const { use: useServer, provider: ServerProvider } = createSimpleContext(
 
     const origin = createMemo(() => projectsKey(state.active))
     const projectsList = createMemo(() => store.projects[origin()] ?? [])
+    const projects = () => {
+      const key = origin()
+      if (!key) return
+      return {
+        key,
+        list: store.projects[key] ?? [],
+      }
+    }
     const current: Accessor<ServerConnection.Any | undefined> = createMemo(
       () => allServers().find((s) => ServerConnection.key(s) === state.active) ?? allServers()[0],
     )
@@ -237,54 +264,49 @@ export const { use: useServer, provider: ServerProvider } = createSimpleContext(
       remove,
       projects: {
         list: projectsList,
-        open(directory: string) {
-          const key = origin()
-          if (!key) return
-          const current = store.projects[key] ?? []
-          if (current.find((x) => x.worktree === directory)) return
-          setStore("projects", key, [{ worktree: directory, expanded: true }, ...current])
+        open(directory: WorkspacePath) {
+          const current = projects()
+          if (!current) return
+          setStore("projects", current.key, upsertProject(current.list, directory))
         },
-        close(directory: string) {
-          const key = origin()
-          if (!key) return
-          const current = store.projects[key] ?? []
+        close(directory: WorkspacePath) {
+          const current = projects()
+          if (!current) return
+          const id = workspacePathKey(directory)
           setStore(
             "projects",
-            key,
-            current.filter((x) => x.worktree !== directory),
+            current.key,
+            current.list.filter((item) => workspacePathKey(item.worktree) !== id),
           )
         },
-        expand(directory: string) {
-          const key = origin()
-          if (!key) return
-          const current = store.projects[key] ?? []
-          const index = current.findIndex((x) => x.worktree === directory)
-          if (index !== -1) setStore("projects", key, index, "expanded", true)
+        expand(directory: WorkspacePath) {
+          const current = projects()
+          if (!current) return
+          const index = projectIndex(current.list, directory)
+          if (index !== -1) setStore("projects", current.key, index, "expanded", true)
         },
-        collapse(directory: string) {
-          const key = origin()
-          if (!key) return
-          const current = store.projects[key] ?? []
-          const index = current.findIndex((x) => x.worktree === directory)
-          if (index !== -1) setStore("projects", key, index, "expanded", false)
+        collapse(directory: WorkspacePath) {
+          const current = projects()
+          if (!current) return
+          const index = projectIndex(current.list, directory)
+          if (index !== -1) setStore("projects", current.key, index, "expanded", false)
         },
-        move(directory: string, toIndex: number) {
-          const key = origin()
-          if (!key) return
-          const current = store.projects[key] ?? []
-          const fromIndex = current.findIndex((x) => x.worktree === directory)
+        move(directory: WorkspacePath, toIndex: number) {
+          const current = projects()
+          if (!current) return
+          const fromIndex = projectIndex(current.list, directory)
           if (fromIndex === -1 || fromIndex === toIndex) return
-          const result = [...current]
+          const result = [...current.list]
           const [item] = result.splice(fromIndex, 1)
           result.splice(toIndex, 0, item)
-          setStore("projects", key, result)
+          setStore("projects", current.key, result)
         },
         last() {
           const key = origin()
           if (!key) return
           return store.lastProject[key]
         },
-        touch(directory: string) {
+        touch(directory: WorkspacePath) {
           const key = origin()
           if (!key) return
           setStore("lastProject", key, directory)
diff --git a/packages/app/src/context/sync.tsx b/packages/app/src/context/sync.tsx
index 0f2008723456..07c4ca5207f6 100644
--- a/packages/app/src/context/sync.tsx
+++ b/packages/app/src/context/sync.tsx
@@ -3,6 +3,7 @@ import { createStore, produce, reconcile } from "solid-js/store"
 import { Binary } from "@opencode-ai/util/binary"
 import { retry } from "@opencode-ai/util/retry"
 import { createSimpleContext } from "@opencode-ai/ui/context"
+import { workspacePathKey } from "@/context/file/path"
 import {
   clearSessionPrefetch,
   getSessionPrefetch,
@@ -10,6 +11,7 @@ import {
   setSessionPrefetch,
 } from "./global-sync/session-prefetch"
 import { useGlobalSync } from "./global-sync"
+import { normalizeSessionDiffs } from "./global-sync/event-reducer"
 import { useSDK } from "./sdk"
 import type { Message, Part } from "@opencode-ai/sdk/v2/client"
 import { SESSION_CACHE_LIMIT, dropSessionCaches, pickSessionCacheEvictions } from "./global-sync/session-cache"
@@ -28,7 +30,9 @@ function runInflight(map: Map<string, Promise<void>>, key: string, task: () => P
   return promise
 }
 
-const keyFor = (directory: string, id: string) => `${directory}\n${id}`
+const dir = (directory: string) => workspacePathKey(directory)
+
+const keyFor = (directory: string, id: string) => `${dir(directory)}\n${id}`
 
 const cmp = (a: string, b: string) => (a < b ? -1 : a > b ? 1 : 0)
 
@@ -227,6 +231,7 @@ export const { use: useSync, provider: SyncProvider } = createSimpleContext({
     ]
 
     const seenFor = (directory: string) => {
+      directory = dir(directory)
       const existing = seen.get(directory)
       if (existing) {
         seen.delete(directory)
@@ -308,7 +313,7 @@ export const { use: useSync, provider: SyncProvider } = createSimpleContext({
       }
     }
 
-    const tracked = (directory: string, sessionID: string) => seen.get(directory)?.has(sessionID) ?? false
+    const tracked = (directory: string, sessionID: string) => seen.get(dir(directory))?.has(sessionID) ?? false
 
     const loadMessages = async (input: {
       directory: string
@@ -506,7 +511,7 @@ export const { use: useSync, provider: SyncProvider } = createSimpleContext({
           return runInflight(inflightDiff, key, () =>
             retry(() => client.session.diff({ sessionID })).then((diff) => {
               if (!tracked(directory, sessionID)) return
-              setStore("session_diff", sessionID, reconcile(diff.data ?? [], { key: "file" }))
+              setStore("session_diff", sessionID, reconcile(normalizeSessionDiffs(diff.data ?? []), { key: "file" }))
             }),
           )
         },
diff --git a/packages/app/src/context/terminal.test.ts b/packages/app/src/context/terminal.test.ts
index 6e07e0312412..72ee3f1f5327 100644
--- a/packages/app/src/context/terminal.test.ts
+++ b/packages/app/src/context/terminal.test.ts
@@ -28,15 +28,20 @@ describe("getWorkspaceTerminalCacheKey", () => {
 })
 
 describe("getLegacyTerminalStorageKeys", () => {
-  test("keeps workspace storage path when no legacy session id", () => {
-    expect(getLegacyTerminalStorageKeys("/repo")).toEqual(["/repo/terminal.v1"])
+  test("includes workspace path aliases when no legacy session id", () => {
+    const keys = getLegacyTerminalStorageKeys("/repo")
+
+    expect(keys).toContain("/repo/terminal.v1")
+    expect(keys).toContain("/repo//terminal.v1")
   })
 
-  test("includes legacy session path before workspace path", () => {
-    expect(getLegacyTerminalStorageKeys("/repo", "session-123")).toEqual([
-      "/repo/terminal/session-123.v1",
-      "/repo/terminal.v1",
-    ])
+  test("includes equivalent directory spellings for session and workspace keys", () => {
+    const keys = getLegacyTerminalStorageKeys("C:/Repo", "session-123")
+
+    expect(keys).toContain("C:/Repo/terminal/session-123.v1")
+    expect(keys).toContain("C:/Repo/terminal.v1")
+    expect(keys).toContain("c:/repo/terminal/session-123.v1")
+    expect(keys).toContain("C:\\Repo/terminal/session-123.v1")
   })
 })
 
diff --git a/packages/app/src/context/terminal.tsx b/packages/app/src/context/terminal.tsx
index 17355aab9abe..8e928227a256 100644
--- a/packages/app/src/context/terminal.tsx
+++ b/packages/app/src/context/terminal.tsx
@@ -87,8 +87,13 @@ export function getWorkspaceTerminalCacheKey(dir: string) {
 }
 
 export function getLegacyTerminalStorageKeys(dir: string, legacySessionID?: string) {
-  if (!legacySessionID) return [`${dir}/terminal.v1`]
-  return [`${dir}/terminal/${legacySessionID}.v1`, `${dir}/terminal.v1`]
+  const keys = legacySessionID
+    ? [
+        ...Persist.legacyScoped(dir, legacySessionID, "terminal", "v1"),
+        ...Persist.legacyScoped(dir, undefined, "terminal", "v1"),
+      ]
+    : Persist.legacyScoped(dir, undefined, "terminal", "v1")
+  return Array.from(new Set(keys))
 }
 
 type TerminalSession = ReturnType<typeof createWorkspaceTerminalSession>
@@ -117,17 +122,20 @@ export function clearWorkspaceTerminals(dir: string, sessionIDs?: string[], plat
     entry?.value.clear()
   }
 
-  removePersisted(Persist.workspace(dir, "terminal"), platform)
-
   const legacy = new Set(getLegacyTerminalStorageKeys(dir))
   for (const id of sessionIDs ?? []) {
     for (const key of getLegacyTerminalStorageKeys(dir, id)) {
       legacy.add(key)
     }
   }
-  for (const key of legacy) {
-    removePersisted({ key }, platform)
-  }
+
+  removePersisted(
+    {
+      ...Persist.workspace(dir, "terminal"),
+      legacy: Array.from(legacy),
+    },
+    platform,
+  )
 }
 
 function createWorkspaceTerminalSession(sdk: ReturnType<typeof useSDK>, dir: string, legacySessionID?: string) {
diff --git a/packages/app/src/pages/layout.tsx b/packages/app/src/pages/layout.tsx
index 0c10cc89bce2..443eb776291a 100644
--- a/packages/app/src/pages/layout.tsx
+++ b/packages/app/src/pages/layout.tsx
@@ -16,6 +16,7 @@ import { useNavigate, useParams } from "@solidjs/router"
 import { useLayout, LocalProject } from "@/context/layout"
 import { useGlobalSync } from "@/context/global-sync"
 import { Persist, persisted } from "@/utils/persist"
+import { migrateLayoutPageState } from "@/utils/persist-path"
 import { base64Encode } from "@opencode-ai/util/encode"
 import { decode64 } from "@/utils/base64"
 import { ResizeHandle } from "@opencode-ai/ui/resize-handle"
@@ -35,6 +36,7 @@ import { useProviders } from "@/hooks/use-providers"
 import { showToast, Toast, toaster } from "@opencode-ai/ui/toast"
 import { useGlobalSDK } from "@/context/global-sdk"
 import { clearWorkspaceTerminals } from "@/context/terminal"
+import { workspacePathKey, type WorkspaceKey, type WorkspacePath } from "@/context/file/path"
 import { dropSessionCaches, pickSessionCacheEvictions } from "@/context/global-sync/session-cache"
 import {
   clearSessionPrefetchInflight,
@@ -72,9 +74,10 @@ import {
   displayName,
   effectiveWorkspaceOrder,
   errorMessage,
+  findProjectByDirectory,
   latestRootSession,
   sortedRootSessions,
-  workspaceKey,
+  workspaceEqual,
 } from "./layout/helpers"
 import {
   collectNewSessionDeepLinks,
@@ -92,17 +95,35 @@ import {
 import { ProjectDragOverlay, SortableProject, type ProjectSidebarContext } from "./layout/sidebar-project"
 import { SidebarContent } from "./layout/sidebar-shell"
 
+type StoredRoute = {
+  directory: WorkspacePath
+  id: string
+  at: number
+}
+
+function mergeWorkspaceOrder(root: WorkspacePath, list: WorkspacePath[]) {
+  const seen = new Set<WorkspaceKey>([workspacePathKey(root)])
+  const out: WorkspacePath[] = []
+
+  for (const directory of list) {
+    const id = workspacePathKey(directory)
+    if (seen.has(id)) continue
+    seen.add(id)
+    out.push(directory)
+  }
+
+  return out
+}
+
 export default function Layout(props: ParentProps) {
   const [store, setStore, , ready] = persisted(
-    Persist.global("layout.page", ["layout.page.v1"]),
+    { ...Persist.global("layout.page", ["layout.page.v1"]), migrate: migrateLayoutPageState },
     createStore({
-      lastProjectSession: {} as { [directory: string]: { directory: string; id: string; at: number } },
-      activeProject: undefined as string | undefined,
-      activeWorkspace: undefined as string | undefined,
-      workspaceOrder: {} as Record<string, string[]>,
-      workspaceName: {} as Record<string, string>,
+      lastProjectSession: {} as Record<WorkspaceKey, StoredRoute>,
+      workspaceOrder: {} as Record<WorkspaceKey, WorkspacePath[]>,
+      workspaceName: {} as Record<WorkspaceKey, string>,
       workspaceBranchName: {} as Record<string, Record<string, string>>,
-      workspaceExpanded: {} as Record<string, boolean>,
+      workspaceExpanded: {} as Record<WorkspaceKey, boolean>,
       gettingStartedDismissed: false,
     }),
   )
@@ -151,20 +172,24 @@ export default function Layout(props: ParentProps) {
 
   const [state, setState] = createStore({
     autoselect: !initialDirectory,
-    busyWorkspaces: {} as Record<string, boolean>,
+    busyWorkspaces: {} as Record<WorkspaceKey, boolean>,
+    drag: {
+      project: undefined as WorkspacePath | undefined,
+      workspace: undefined as WorkspacePath | undefined,
+    },
     hoverSession: undefined as string | undefined,
-    hoverProject: undefined as string | undefined,
+    hoverProject: undefined as WorkspacePath | undefined,
     scrollSessionKey: undefined as string | undefined,
     nav: undefined as HTMLElement | undefined,
     sortNow: Date.now(),
     sizing: false,
-    peek: undefined as string | undefined,
+    peek: undefined as WorkspacePath | undefined,
     peeked: false,
   })
 
   const editor = createInlineEditorController()
-  const setBusy = (directory: string, value: boolean) => {
-    const key = workspaceKey(directory)
+  const setBusy = (directory: WorkspacePath, value: boolean) => {
+    const key = workspacePathKey(directory)
     if (value) {
       setState("busyWorkspaces", key, true)
       return
@@ -176,7 +201,7 @@ export default function Layout(props: ParentProps) {
       }),
     )
   }
-  const isBusy = (directory: string) => !!state.busyWorkspaces[workspaceKey(directory)]
+  const isBusy = (directory: WorkspacePath) => !!state.busyWorkspaces[workspacePathKey(directory)]
   const navLeave = { current: undefined as number | undefined }
   const sortNow = () => state.sortNow
   let sizet: number | undefined
@@ -223,7 +248,7 @@ export default function Layout(props: ParentProps) {
 
   const sidebarHovering = createMemo(() => !layout.sidebar.opened() && state.hoverProject !== undefined)
   const sidebarExpanded = createMemo(() => layout.sidebar.opened() || sidebarHovering())
-  const setHoverProject = (value: string | undefined) => {
+  const setHoverProject = (value: WorkspacePath | undefined) => {
     setState("hoverProject", value)
     if (value !== undefined) return
     aim.reset()
@@ -253,13 +278,13 @@ export default function Layout(props: ParentProps) {
   const hoverProjectData = createMemo(() => {
     const id = state.hoverProject
     if (!id) return
-    return layout.projects.list().find((project) => project.worktree === id)
+    return layout.projects.list().find((project) => workspaceEqual(project.worktree, id))
   })
 
   const peekProject = createMemo(() => {
     const id = state.peek
     if (!id) return
-    return layout.projects.list().find((project) => project.worktree === id)
+    return layout.projects.list().find((project) => workspaceEqual(project.worktree, id))
   })
 
   createEffect(() => {
@@ -446,7 +471,7 @@ export default function Layout(props: ParentProps) {
           e.details?.type === "permission.replied"
         ) {
           const props = e.details.properties as { sessionID: string }
-          const sessionKey = `${e.name}:${props.sessionID}`
+          const sessionKey = alertKey(e.name, props.sessionID)
           dismissSessionAlert(sessionKey)
           return
         }
@@ -463,7 +488,7 @@ export default function Layout(props: ParentProps) {
 
         const [store] = globalSync.child(directory, { bootstrap: false })
         const session = store.session.find((s) => s.id === props.sessionID)
-        const sessionKey = `${directory}:${props.sessionID}`
+        const sessionKey = alertKey(directory, props.sessionID)
 
         const sessionTitle = session?.title ?? language.t("command.session.new")
         const projectName = getFilename(directory)
@@ -494,8 +519,8 @@ export default function Layout(props: ParentProps) {
         }
 
         const currentSession = params.id
-        if (workspaceKey(directory) === workspaceKey(currentDir()) && props.sessionID === currentSession) return
-        if (workspaceKey(directory) === workspaceKey(currentDir()) && session?.parentID === currentSession) return
+        if (workspaceEqual(directory, currentDir()) && props.sessionID === currentSession) return
+        if (workspaceEqual(directory, currentDir()) && session?.parentID === currentSession) return
 
         dismissSessionAlert(sessionKey)
 
@@ -522,12 +547,12 @@ export default function Layout(props: ParentProps) {
       createEffect(() => {
         const currentSession = params.id
         if (!currentDir() || !currentSession) return
-        const sessionKey = `${currentDir()}:${currentSession}`
+        const sessionKey = alertKey(currentDir(), currentSession)
         dismissSessionAlert(sessionKey)
         const [store] = globalSync.child(currentDir(), { bootstrap: false })
         const childSessions = store.session.filter((s) => s.parentID === currentSession)
         for (const child of childSessions) {
-          dismissSessionAlert(`${currentDir()}:${child.id}`)
+          dismissSessionAlert(alertKey(currentDir(), child.id))
         }
       })
     })
@@ -553,14 +578,10 @@ export default function Layout(props: ParentProps) {
   const currentProject = createMemo(() => {
     const directory = currentDir()
     if (!directory) return
-    const key = workspaceKey(directory)
 
     const projects = layout.projects.list()
 
-    const sandbox = projects.find((p) => p.sandboxes?.some((item) => workspaceKey(item) === key))
-    if (sandbox) return sandbox
-
-    const direct = projects.find((p) => workspaceKey(p.worktree) === key)
+    const direct = findProjectByDirectory(projects, directory)
     if (direct) return direct
 
     const [child] = globalSync.child(directory, { bootstrap: false })
@@ -571,9 +592,19 @@ export default function Layout(props: ParentProps) {
     const root = meta?.worktree
     if (!root) return
 
-    return projects.find((p) => p.worktree === root)
+    return findProjectByDirectory(projects, root)
   })
 
+  const keyOf = (directory: WorkspacePath) => workspacePathKey(directory)
+  const alertKey = (directory: WorkspacePath, sessionID: string) => `${keyOf(directory)}:${sessionID}`
+  const routeFor = (root: WorkspacePath) => store.lastProjectSession[keyOf(root)]
+  const orderFor = (root: WorkspacePath, dirs: WorkspacePath[]) =>
+    effectiveWorkspaceOrder(root, dirs, store.workspaceOrder[keyOf(root)])
+  const includes = (dirs: WorkspacePath[], directory: WorkspacePath | undefined) => {
+    if (!directory) return false
+    return dirs.some((item) => workspaceEqual(item, directory))
+  }
+
   const [autoselecting] = createResource(async () => {
     await ready.promise
     await layout.ready.promise
@@ -586,23 +617,22 @@ export default function Layout(props: ParentProps) {
       if (!last) return
       await openProject(last, true)
     } else {
-      const next = list.find((project) => project.worktree === last) ?? list[0]
+      const next = list.find((project) => workspaceEqual(project.worktree, last)) ?? list[0]
       if (!next) return
       await openProject(next.worktree, true)
     }
   })
 
-  const workspaceName = (directory: string, projectId?: string, branch?: string) => {
-    const key = workspaceKey(directory)
-    const direct = store.workspaceName[key] ?? store.workspaceName[directory]
+  const workspaceName = (directory: WorkspacePath, projectId?: string, branch?: string) => {
+    const direct = store.workspaceName[keyOf(directory)]
     if (direct) return direct
     if (!projectId) return
     if (!branch) return
     return store.workspaceBranchName[projectId]?.[branch]
   }
 
-  const setWorkspaceName = (directory: string, next: string, projectId?: string, branch?: string) => {
-    const key = workspaceKey(directory)
+  const setWorkspaceName = (directory: WorkspacePath, next: string, projectId?: string, branch?: string) => {
+    const key = keyOf(directory)
     setStore("workspaceName", key, next)
     if (!projectId) return
     if (!branch) return
@@ -612,7 +642,7 @@ export default function Layout(props: ParentProps) {
     setStore("workspaceBranchName", projectId, branch, next)
   }
 
-  const workspaceLabel = (directory: string, branch?: string, projectId?: string) =>
+  const workspaceLabel = (directory: WorkspacePath, branch?: string, projectId?: string) =>
     workspaceName(directory, projectId, branch) ?? branch ?? getFilename(directory)
 
   const workspaceSetting = createMemo(() => {
@@ -629,8 +659,8 @@ export default function Layout(props: ParentProps) {
 
     const activeDir = currentDir()
     return workspaceIds(project).filter((directory) => {
-      const expanded = store.workspaceExpanded[directory] ?? directory === project.worktree
-      const active = workspaceKey(directory) === workspaceKey(activeDir)
+      const expanded = store.workspaceExpanded[keyOf(directory)] ?? workspaceEqual(directory, project.worktree)
+      const active = workspaceEqual(directory, activeDir)
       return expanded || active
     })
   })
@@ -641,14 +671,10 @@ export default function Layout(props: ParentProps) {
     const projects = layout.projects.list()
     for (const [directory, expanded] of Object.entries(store.workspaceExpanded)) {
       if (!expanded) continue
-      const key = workspaceKey(directory)
-      const project = projects.find(
-        (item) =>
-          workspaceKey(item.worktree) === key || item.sandboxes?.some((sandbox) => workspaceKey(sandbox) === key),
-      )
+      const project = findProjectByDirectory(projects, directory)
       if (!project) continue
       if (project.vcs === "git" && layout.sidebar.workspaces(project.worktree)()) continue
-      setStore("workspaceExpanded", directory, false)
+      setStore("workspaceExpanded", directory as WorkspaceKey, false)
     }
   })
 
@@ -678,12 +704,12 @@ export default function Layout(props: ParentProps) {
   const prefetchPendingLimit = 10
   const span = 4
   const prefetchToken = { value: 0 }
-  const prefetchQueues = new Map<string, PrefetchQueue>()
+  const prefetchQueues = new Map<WorkspacePath, PrefetchQueue>()
 
   const PREFETCH_MAX_SESSIONS_PER_DIR = 10
-  const prefetchedByDir = new Map<string, Set<string>>()
+  const prefetchedByDir = new Map<WorkspacePath, Set<string>>()
 
-  const lruFor = (directory: string) => {
+  const lruFor = (directory: WorkspacePath) => {
     const existing = prefetchedByDir.get(directory)
     if (existing) return existing
     const created = new Set<string>()
@@ -691,13 +717,13 @@ export default function Layout(props: ParentProps) {
     return created
   }
 
-  const markPrefetched = (directory: string, sessionID: string) => {
+  const markPrefetched = (directory: WorkspacePath, sessionID: string) => {
     const lru = lruFor(directory)
     return pickSessionCacheEvictions({
       seen: lru,
       keep: sessionID,
       limit: PREFETCH_MAX_SESSIONS_PER_DIR,
-      preserve: params.id && workspaceKey(directory) === workspaceKey(currentDir()) ? [params.id] : undefined,
+      preserve: workspaceEqual(directory, currentDir()) && params.id ? [params.id] : undefined,
     })
   }
 
@@ -728,7 +754,7 @@ export default function Layout(props: ParentProps) {
     }
   })
 
-  const queueFor = (directory: string) => {
+  const queueFor = (directory: WorkspacePath) => {
     const existing = prefetchQueues.get(directory)
     if (existing) return existing
 
@@ -757,7 +783,7 @@ export default function Layout(props: ParentProps) {
     return [...map.values()].sort((a, b) => (a.id < b.id ? -1 : a.id > b.id ? 1 : 0))
   }
 
-  async function prefetchMessages(directory: string, sessionID: string, token: number) {
+  async function prefetchMessages(directory: WorkspacePath, sessionID: string, token: number) {
     const [store, setStore] = globalSync.child(directory, { bootstrap: false })
 
     return runSessionPrefetch({
@@ -825,7 +851,7 @@ export default function Layout(props: ParentProps) {
     })
   }
 
-  const pumpPrefetch = (directory: string) => {
+  const pumpPrefetch = (directory: WorkspacePath) => {
     const q = queueFor(directory)
     if (q.running >= prefetchConcurrency) return
 
@@ -1203,18 +1229,12 @@ export default function Layout(props: ParentProps) {
     dialog.show(() => <DialogSettings />)
   }
 
-  function projectRoot(directory: string) {
-    const key = workspaceKey(directory)
-    const project = layout.projects
-      .list()
-      .find(
-        (item) =>
-          workspaceKey(item.worktree) === key || item.sandboxes?.some((sandbox) => workspaceKey(sandbox) === key),
-      )
+  function projectRoot(directory: WorkspacePath) {
+    const project = findProjectByDirectory(layout.projects.list(), directory)
     if (project) return project.worktree
 
     const known = Object.entries(store.workspaceOrder).find(
-      ([root, dirs]) => workspaceKey(root) === key || dirs.some((item) => workspaceKey(item) === key),
+      ([root, dirs]) => workspaceEqual(root, directory) || dirs.some((dir) => workspaceEqual(dir, directory)),
     )
     if (known) return known[0]
 
@@ -1226,62 +1246,66 @@ export default function Layout(props: ParentProps) {
     return meta?.worktree ?? directory
   }
 
-  function activeProjectRoot(directory: string) {
+  function activeProjectRoot(directory: WorkspacePath) {
     return currentProject()?.worktree ?? projectRoot(directory)
   }
 
-  function rememberSessionRoute(directory: string, id: string, root = activeProjectRoot(directory)) {
-    setStore("lastProjectSession", root, { directory, id, at: Date.now() })
+  function touchProjectRoute() {
+    const root = currentProject()?.worktree
+    if (!root) return
+    if (!workspaceEqual(server.projects.last(), root)) server.projects.touch(root)
+    return root
+  }
+
+  function rememberSessionRoute(directory: WorkspacePath, id: string, root = activeProjectRoot(directory)) {
+    setStore("lastProjectSession", keyOf(root), { directory, id, at: Date.now() })
     return root
   }
 
-  function clearLastProjectSession(root: string) {
-    if (!store.lastProjectSession[root]) return
+  function clearLastProjectSession(root: WorkspacePath) {
+    const key = keyOf(root)
+    if (!store.lastProjectSession[key]) return
     setStore(
       "lastProjectSession",
       produce((draft) => {
-        delete draft[root]
+        delete draft[key]
       }),
     )
   }
 
-  function syncSessionRoute(directory: string, id: string, root = activeProjectRoot(directory)) {
+  function syncSessionRoute(directory: WorkspacePath, id: string, root = activeProjectRoot(directory)) {
     rememberSessionRoute(directory, id, root)
     notification.session.markViewed(id)
-    const expanded = untrack(() => store.workspaceExpanded[directory])
+    const key = keyOf(directory)
+    const expanded = untrack(() => store.workspaceExpanded[key])
     if (expanded === false) {
-      setStore("workspaceExpanded", directory, true)
+      setStore("workspaceExpanded", key, true)
     }
     requestAnimationFrame(() => scrollToSession(id, `${directory}:${id}`))
     return root
   }
 
-  async function navigateToProject(directory: string | undefined) {
+  async function navigateToProject(directory: WorkspacePath | undefined) {
     if (!directory) return
     const root = projectRoot(directory)
     server.projects.touch(root)
-    const project = layout.projects.list().find((item) => item.worktree === root)
-    let dirs = project
-      ? effectiveWorkspaceOrder(root, [root, ...(project.sandboxes ?? [])], store.workspaceOrder[root])
-      : [root]
-    const canOpen = (value: string | undefined) => {
-      if (!value) return false
-      return dirs.some((item) => workspaceKey(item) === workspaceKey(value))
-    }
+    const project = layout.projects.list().find((item) => workspaceEqual(item.worktree, root))
+    let dirs = project ? orderFor(root, [root, ...(project.sandboxes ?? [])]) : [root]
+    const canOpen = (value: WorkspacePath | undefined) => includes(dirs, value)
     const refreshDirs = async (target?: string) => {
-      if (!target || target === root || canOpen(target)) return canOpen(target)
+      if (!target || workspaceEqual(target, root) || canOpen(target)) return canOpen(target)
       const listed = await globalSDK.client.worktree
         .list({ directory: root })
         .then((x) => x.data ?? [])
         .catch(() => [] as string[])
-      dirs = effectiveWorkspaceOrder(root, [root, ...listed], store.workspaceOrder[root])
+      dirs = orderFor(root, [root, ...listed])
       return canOpen(target)
     }
     const openSession = async (target: { directory: string; id: string }) => {
       if (!canOpen(target.directory)) return false
       const [data] = globalSync.child(target.directory, { bootstrap: false })
       if (data.session.some((item) => item.id === target.id)) {
-        setStore("lastProjectSession", root, { directory: target.directory, id: target.id, at: Date.now() })
+        rememberSessionRoute(target.directory, target.id, root)
         navigateWithSidebarReset(`/${base64Encode(target.directory)}/session/${target.id}`)
         return true
       }
@@ -1291,12 +1315,12 @@ export default function Layout(props: ParentProps) {
         .catch(() => undefined)
       if (!resolved?.directory) return false
       if (!canOpen(resolved.directory)) return false
-      setStore("lastProjectSession", root, { directory: resolved.directory, id: resolved.id, at: Date.now() })
+      rememberSessionRoute(resolved.directory, resolved.id, root)
       navigateWithSidebarReset(`/${base64Encode(resolved.directory)}/session/${resolved.id}`)
       return true
     }
 
-    const projectSession = store.lastProjectSession[root]
+    const projectSession = routeFor(root)
     if (projectSession?.id) {
       await refreshDirs(projectSession.directory)
       const opened = await openSession(projectSession)
@@ -1336,7 +1360,7 @@ export default function Layout(props: ParentProps) {
     navigateWithSidebarReset(`/${base64Encode(session.directory)}/session/${session.id}`)
   }
 
-  function openProject(directory: string, navigate = true) {
+  function openProject(directory: WorkspacePath, navigate = true) {
     layout.projects.open(directory)
     if (navigate) return navigateToProject(directory)
   }
@@ -1385,17 +1409,16 @@ export default function Layout(props: ParentProps) {
     globalSync.project.meta(project.worktree, { name })
   }
 
-  const renameWorkspace = (directory: string, next: string, projectId?: string, branch?: string) => {
+  const renameWorkspace = (directory: WorkspacePath, next: string, projectId?: string, branch?: string) => {
     const current = workspaceName(directory, projectId, branch) ?? branch ?? getFilename(directory)
     if (current === next) return
     setWorkspaceName(directory, next, projectId, branch)
   }
 
-  function closeProject(directory: string) {
+  function closeProject(directory: WorkspacePath) {
     const list = layout.projects.list()
-    const key = workspaceKey(directory)
-    const index = list.findIndex((x) => workspaceKey(x.worktree) === key)
-    const active = workspaceKey(currentProject()?.worktree ?? "") === key
+    const index = list.findIndex((x) => workspaceEqual(x.worktree, directory))
+    const active = workspaceEqual(currentProject()?.worktree, directory)
     if (index === -1) return
     const next = list[index + 1]
 
@@ -1455,13 +1478,11 @@ export default function Layout(props: ParentProps) {
     }
   }
 
-  const deleteWorkspace = async (root: string, directory: string, leaveDeletedWorkspace = false) => {
-    if (directory === root) return
+  const deleteWorkspace = async (root: WorkspacePath, directory: WorkspacePath, leaveDeletedWorkspace = false) => {
+    if (workspaceEqual(directory, root)) return
 
     const current = currentDir()
-    const currentKey = workspaceKey(current)
-    const deletedKey = workspaceKey(directory)
-    const shouldLeave = leaveDeletedWorkspace || (!!params.dir && currentKey === deletedKey)
+    const shouldLeave = leaveDeletedWorkspace || (!!params.dir && workspaceEqual(current, directory))
     if (!leaveDeletedWorkspace && shouldLeave) {
       navigateWithSidebarReset(`/${base64Encode(root)}/session`)
     }
@@ -1483,19 +1504,22 @@ export default function Layout(props: ParentProps) {
 
     if (!result) return
 
-    if (workspaceKey(store.lastProjectSession[root]?.directory ?? "") === workspaceKey(directory)) {
+    const saved = routeFor(root)?.directory
+    if (saved && workspaceEqual(saved, directory)) {
       clearLastProjectSession(root)
     }
 
     globalSync.set(
       "project",
       produce((draft) => {
-        const project = draft.find((item) => item.worktree === root)
+        const project = draft.find((item) => workspaceEqual(item.worktree, root))
         if (!project) return
-        project.sandboxes = (project.sandboxes ?? []).filter((sandbox) => sandbox !== directory)
+        project.sandboxes = (project.sandboxes ?? []).filter((sandbox) => !workspaceEqual(sandbox, directory))
       }),
     )
-    setStore("workspaceOrder", root, (order) => (order ?? []).filter((workspace) => workspace !== directory))
+    setStore("workspaceOrder", keyOf(root), (order) =>
+      (order ?? []).filter((workspace) => !workspaceEqual(workspace, directory)),
+    )
 
     layout.projects.close(directory)
     layout.projects.open(root)
@@ -1503,20 +1527,17 @@ export default function Layout(props: ParentProps) {
     if (shouldLeave) return
 
     const nextCurrent = currentDir()
-    const nextKey = workspaceKey(nextCurrent)
-    const project = layout.projects.list().find((item) => item.worktree === root)
-    const dirs = project
-      ? effectiveWorkspaceOrder(root, [root, ...(project.sandboxes ?? [])], store.workspaceOrder[root])
-      : [root]
-    const valid = dirs.some((item) => workspaceKey(item) === nextKey)
-
-    if (params.dir && projectRoot(nextCurrent) === root && !valid) {
+    const project = layout.projects.list().find((item) => workspaceEqual(item.worktree, root))
+    const dirs = project ? orderFor(root, [root, ...(project.sandboxes ?? [])]) : [root]
+    const valid = includes(dirs, nextCurrent)
+
+    if (params.dir && workspaceEqual(projectRoot(nextCurrent), root) && !valid) {
       navigateWithSidebarReset(`/${base64Encode(root)}/session`)
     }
   }
 
-  const resetWorkspace = async (root: string, directory: string) => {
-    if (directory === root) return
+  const resetWorkspace = async (root: WorkspacePath, directory: WorkspacePath) => {
+    if (workspaceEqual(directory, root)) return
     setBusy(directory, true)
 
     const progress = showToast({
@@ -1593,7 +1614,7 @@ export default function Layout(props: ParentProps) {
     })
   }
 
-  function DialogDeleteWorkspace(props: { root: string; directory: string }) {
+  function DialogDeleteWorkspace(props: { root: WorkspacePath; directory: WorkspacePath }) {
     const name = createMemo(() => getFilename(props.directory))
     const [data, setData] = createStore({
       status: "loading" as "loading" | "ready" | "error",
@@ -1614,7 +1635,7 @@ export default function Layout(props: ParentProps) {
     })
 
     const handleDelete = () => {
-      const leaveDeletedWorkspace = !!params.dir && workspaceKey(currentDir()) === workspaceKey(props.directory)
+      const leaveDeletedWorkspace = !!params.dir && workspaceEqual(currentDir(), props.directory)
       if (leaveDeletedWorkspace) {
         navigateWithSidebarReset(`/${base64Encode(props.root)}/session`)
       }
@@ -1651,7 +1672,7 @@ export default function Layout(props: ParentProps) {
     )
   }
 
-  function DialogResetWorkspace(props: { root: string; directory: string }) {
+  function DialogResetWorkspace(props: { root: WorkspacePath; directory: WorkspacePath }) {
     const name = createMemo(() => getFilename(props.directory))
     const [state, setState] = createStore({
       status: "loading" as "loading" | "ready" | "error",
@@ -1729,8 +1750,8 @@ export default function Layout(props: ParentProps) {
 
   const activeRoute = {
     session: "",
-    sessionProject: "",
-    directory: "",
+    sessionProject: "" as WorkspacePath | "",
+    directory: "" as WorkspacePath | "",
   }
 
   createEffect(
@@ -1772,7 +1793,7 @@ export default function Layout(props: ParentProps) {
           return
         }
 
-        if (root === activeRoute.sessionProject) return
+        if (workspaceEqual(root, activeRoute.sessionProject)) return
         activeRoute.directory = dir
         activeRoute.sessionProject = rememberSessionRoute(dir, id, root)
       },
@@ -1784,7 +1805,7 @@ export default function Layout(props: ParentProps) {
     document.documentElement.style.setProperty("--dialog-left-margin", `${sidebarWidth}px`)
   })
 
-  const loadedSessionDirs = new Set<string>()
+  const loadedSessionDirs = new Set<WorkspacePath>()
 
   createEffect(
     on(
@@ -1814,15 +1835,15 @@ export default function Layout(props: ParentProps) {
     const id = getDraggableId(event)
     if (!id) return
     setHoverProject(undefined)
-    setStore("activeProject", id)
+    setState("drag", "project", id)
   }
 
   function handleDragOver(event: DragEvent) {
     const { draggable, droppable } = event
     if (draggable && droppable) {
       const projects = layout.projects.list()
-      const fromIndex = projects.findIndex((p) => p.worktree === draggable.id.toString())
-      const toIndex = projects.findIndex((p) => p.worktree === droppable.id.toString())
+      const fromIndex = projects.findIndex((p) => workspaceEqual(p.worktree, draggable.id.toString()))
+      const toIndex = projects.findIndex((p) => workspaceEqual(p.worktree, droppable.id.toString()))
       if (fromIndex !== toIndex && toIndex !== -1) {
         layout.projects.move(draggable.id.toString(), toIndex)
       }
@@ -1830,7 +1851,7 @@ export default function Layout(props: ParentProps) {
   }
 
   function handleDragEnd() {
-    setStore("activeProject", undefined)
+    setState("drag", "project", undefined)
   }
 
   function workspaceIds(project: LocalProject | undefined) {
@@ -1838,17 +1859,15 @@ export default function Layout(props: ParentProps) {
     const local = project.worktree
     const dirs = [local, ...(project.sandboxes ?? [])]
     const active = currentProject()
-    const directory = workspaceKey(active?.worktree ?? "") === workspaceKey(project.worktree) ? currentDir() : undefined
+    const directory = workspaceEqual(active?.worktree, project.worktree) ? currentDir() : undefined
     const extra =
-      directory &&
-      workspaceKey(directory) !== workspaceKey(local) &&
-      !dirs.some((item) => workspaceKey(item) === workspaceKey(directory))
+      directory && !workspaceEqual(directory, local) && !dirs.some((dir) => workspaceEqual(dir, directory))
         ? directory
         : undefined
     const pending = extra ? WorktreeState.get(extra)?.status === "pending" : false
 
-    const ordered = effectiveWorkspaceOrder(local, dirs, store.workspaceOrder[project.worktree])
-    if (pending && extra) return [local, extra, ...ordered.filter((item) => item !== local)]
+    const ordered = orderFor(local, dirs)
+    if (pending && extra) return [local, extra, ...ordered.filter((item) => !workspaceEqual(item, local))]
     if (!extra) return ordered
     if (pending) return ordered
     return [...ordered, extra]
@@ -1864,7 +1883,7 @@ export default function Layout(props: ParentProps) {
   function handleWorkspaceDragStart(event: unknown) {
     const id = getDraggableId(event)
     if (!id) return
-    setStore("activeWorkspace", id)
+    setState("drag", "workspace", id)
   }
 
   function handleWorkspaceDragOver(event: DragEvent) {
@@ -1875,8 +1894,8 @@ export default function Layout(props: ParentProps) {
     if (!project) return
 
     const ids = workspaceIds(project)
-    const fromIndex = ids.findIndex((dir) => dir === draggable.id.toString())
-    const toIndex = ids.findIndex((dir) => dir === droppable.id.toString())
+    const fromIndex = ids.findIndex((dir) => workspaceEqual(dir, draggable.id.toString()))
+    const toIndex = ids.findIndex((dir) => workspaceEqual(dir, droppable.id.toString()))
     if (fromIndex === -1 || toIndex === -1) return
     if (fromIndex === toIndex) return
 
@@ -1886,13 +1905,16 @@ export default function Layout(props: ParentProps) {
     result.splice(toIndex, 0, item)
     setStore(
       "workspaceOrder",
-      project.worktree,
-      result.filter((directory) => workspaceKey(directory) !== workspaceKey(project.worktree)),
+      keyOf(project.worktree),
+      mergeWorkspaceOrder(
+        project.worktree,
+        result.filter((directory) => !workspaceEqual(directory, project.worktree)),
+      ),
     )
   }
 
   function handleWorkspaceDragEnd() {
-    setStore("activeWorkspace", undefined)
+    setState("drag", "workspace", undefined)
   }
 
   const createWorkspace = async (project: LocalProject) => {
@@ -1913,22 +1935,13 @@ export default function Layout(props: ParentProps) {
     setWorkspaceName(created.directory, created.branch, project.id, created.branch)
 
     const local = project.worktree
-    const key = workspaceKey(created.directory)
-    const root = workspaceKey(local)
+    const key = workspacePathKey(created.directory)
 
     setBusy(created.directory, true)
     WorktreeState.pending(created.directory)
     setStore("workspaceExpanded", key, true)
-    if (key !== created.directory) {
-      setStore("workspaceExpanded", created.directory, true)
-    }
-    setStore("workspaceOrder", project.worktree, (prev) => {
-      const existing = prev ?? []
-      const next = existing.filter((item) => {
-        const id = workspaceKey(item)
-        return id !== root && id !== key
-      })
-      return [created.directory, ...next]
+    setStore("workspaceOrder", keyOf(project.worktree), (prev) => {
+      return mergeWorkspaceOrder(local, [created.directory, ...(prev ?? [])])
     })
 
     globalSync.child(created.directory)
@@ -1954,8 +1967,8 @@ export default function Layout(props: ParentProps) {
     setEditor,
     InlineEditor,
     isBusy,
-    workspaceExpanded: (directory, local) => store.workspaceExpanded[directory] ?? local,
-    setWorkspaceExpanded: (directory, value) => setStore("workspaceExpanded", directory, value),
+    workspaceExpanded: (directory, local) => store.workspaceExpanded[keyOf(directory)] ?? local,
+    setWorkspaceExpanded: (directory, value) => setStore("workspaceExpanded", keyOf(directory), value),
     showResetWorkspaceDialog: (root, directory) =>
       dialog.show(() => <DialogResetWorkspace root={root} directory={directory} />),
     showDeleteWorkspaceDialog: (root, directory) =>
@@ -2259,7 +2272,7 @@ export default function Layout(props: ParentProps) {
                       <DragOverlay>
                         <WorkspaceDragOverlay
                           sidebarProject={sidebarProject}
-                          activeWorkspace={() => store.activeWorkspace}
+                          activeWorkspace={() => state.drag.workspace}
                           workspaceLabel={workspaceLabel}
                         />
                       </DragOverlay>
@@ -2304,7 +2317,7 @@ export default function Layout(props: ParentProps) {
   }
 
   const projects = () => layout.projects.list()
-  const projectOverlay = () => <ProjectDragOverlay projects={projects} activeProject={() => store.activeProject} />
+  const projectOverlay = () => <ProjectDragOverlay projects={projects} activeProject={() => state.drag.project} />
   const sidebarContent = (mobile?: boolean) => (
     <SidebarContent
       mobile={mobile}
diff --git a/packages/app/src/pages/layout/helpers.test.ts b/packages/app/src/pages/layout/helpers.test.ts
index 1fe52d47a0a6..c2baa79a7bd6 100644
--- a/packages/app/src/pages/layout/helpers.test.ts
+++ b/packages/app/src/pages/layout/helpers.test.ts
@@ -1,4 +1,7 @@
 import { describe, expect, test } from "bun:test"
+import { pathEqual, pathKey } from "@opencode-ai/util/path"
+import { type Session } from "@opencode-ai/sdk/v2/client"
+import { workspacePathKey } from "@/context/file/path"
 import {
   collectNewSessionDeepLinks,
   collectOpenProjectDeepLinks,
@@ -6,14 +9,15 @@ import {
   parseDeepLink,
   parseNewSessionDeepLink,
 } from "./deep-links"
-import { type Session } from "@opencode-ai/sdk/v2/client"
 import {
   displayName,
   effectiveWorkspaceOrder,
   errorMessage,
+  findProjectByDirectory,
   hasProjectPermissions,
   latestRootSession,
-  workspaceKey,
+  projectContains,
+  workspaceEqual,
 } from "./helpers"
 
 const session = (input: Partial<Session> & Pick<Session, "id" | "directory">) =>
@@ -102,17 +106,27 @@ describe("layout deep links", () => {
 })
 
 describe("layout workspace helpers", () => {
-  test("normalizes trailing slash in workspace key", () => {
-    expect(workspaceKey("/tmp/demo///")).toBe("/tmp/demo")
-    expect(workspaceKey("C:\\tmp\\demo\\\\")).toBe("C:/tmp/demo")
+  test("normalizes trailing slash, slash style, and windows case in path keys", () => {
+    expect(pathKey("/tmp/demo///")).toBe("/tmp/demo")
+    expect(pathKey("C:\\Tmp\\Demo\\\\")).toBe("c:/tmp/demo")
+    expect(pathKey("C:/tmp/demo")).toBe("c:/tmp/demo")
+    expect(pathKey("\\\\Server\\Share\\Repo\\\\")).toBe("//server/share/repo")
+  })
+
+  test("preserves posix case sensitivity while folding windows paths", () => {
+    expect(pathEqual("/Tmp/Demo", "/tmp/demo")).toBe(false)
+    expect(pathEqual("C:\\Tmp\\Demo", "c:/tmp/demo")).toBe(true)
+    expect(pathEqual("\\\\Server\\Share\\Repo", "//server/share/repo")).toBe(true)
   })
 
-  test("preserves posix and drive roots in workspace key", () => {
-    expect(workspaceKey("/")).toBe("/")
-    expect(workspaceKey("///")).toBe("/")
-    expect(workspaceKey("C:\\")).toBe("C:/")
-    expect(workspaceKey("C://")).toBe("C:/")
-    expect(workspaceKey("C:///")).toBe("C:/")
+  test("preserves normalized roots in workspace key", () => {
+    expect(String(workspacePathKey("/"))).toBe("/")
+    expect(String(workspacePathKey("///"))).toBe("/")
+    expect(String(workspacePathKey("\\"))).toBe("/")
+    expect(String(workspacePathKey("C:\\"))).toBe("c:/")
+    expect(String(workspacePathKey("C:/"))).toBe("c:/")
+    expect(String(workspacePathKey("C:///"))).toBe("c:/")
+    expect(String(workspacePathKey("\\\\Server\\Share\\"))).toBe("//server/share")
   })
 
   test("keeps local first while preserving known order", () => {
@@ -120,6 +134,16 @@ describe("layout workspace helpers", () => {
     expect(result).toEqual(["/root", "/c", "/b"])
   })
 
+  test("dedupes windows workspace variants in effective order", () => {
+    const result = effectiveWorkspaceOrder(
+      "C:/Root",
+      ["c:\\root\\", "C:/ROOT/feature", "c:\\root\\FEATURE\\"],
+      ["c:/root", "c:/root/feature"],
+    )
+
+    expect(result).toEqual(["C:/Root", "C:/ROOT/feature"])
+  })
+
   test("finds the latest root session across workspaces", () => {
     const result = latestRootSession(
       [
@@ -144,6 +168,38 @@ describe("layout workspace helpers", () => {
     expect(result?.id).toBe("workspace")
   })
 
+  test("matches root sessions with normalized workspace keys", () => {
+    const result = latestRootSession(
+      [
+        {
+          path: { directory: "C:/Workspace" },
+          session: [
+            session({
+              id: "win",
+              directory: "c:\\workspace\\",
+              time: { created: 10, updated: 10, archived: undefined },
+            }),
+          ],
+        },
+      ],
+      120_000,
+    )
+
+    expect(result?.id).toBe("win")
+  })
+
+  test("matches projects by normalized worktree and workspace paths", () => {
+    const projects = [
+      { worktree: "C:/Workspace", sandboxes: ["C:/Workspace/Feature"] },
+      { worktree: "/tmp/demo", sandboxes: ["/tmp/demo/branch"] },
+    ]
+
+    expect(projectContains(projects[0], "c:\\workspace\\feature\\")).toBe(true)
+    expect(findProjectByDirectory(projects, "c:\\workspace\\")).toBe(projects[0])
+    expect(findProjectByDirectory(projects, "/tmp/demo/branch")).toBe(projects[1])
+    expect(workspaceEqual("/tmp/demo", "/Tmp/demo")).toBe(false)
+  })
+
   test("detects project permissions with a filter", () => {
     const result = hasProjectPermissions(
       {
diff --git a/packages/app/src/pages/layout/helpers.ts b/packages/app/src/pages/layout/helpers.ts
index 226098c1cd66..7b098241c06e 100644
--- a/packages/app/src/pages/layout/helpers.ts
+++ b/packages/app/src/pages/layout/helpers.ts
@@ -1,19 +1,29 @@
-import { getFilename } from "@opencode-ai/util/path"
+import { getFilename, pathEqual, pathKey } from "@opencode-ai/util/path"
 import { type Session } from "@opencode-ai/sdk/v2/client"
+import { workspacePathKey } from "@/context/file/path"
+
+export const workspaceEqual = pathEqual
+export const workspaceKey = pathKey
+
+export const projectContains = (project: { worktree: string; sandboxes?: string[] }, directory: string | undefined) => {
+  if (!directory) return false
+  if (pathEqual(project.worktree, directory)) return true
+  return project.sandboxes?.some((sandbox) => pathEqual(sandbox, directory)) === true
+}
+
+export const findProjectByDirectory = <T extends { worktree: string; sandboxes?: string[] }>(
+  projects: T[],
+  directory: string | undefined,
+) => {
+  if (!directory) return
+  return projects.find((project) => projectContains(project, directory))
+}
 
 type SessionStore = {
   session?: Session[]
   path: { directory: string }
 }
 
-export const workspaceKey = (directory: string) => {
-  const value = directory.replaceAll("\\", "/")
-  const drive = value.match(/^([A-Za-z]:)\/+$/)
-  if (drive) return `${drive[1]}/`
-  if (/^\/+$/i.test(value)) return "/"
-  return value.replace(/\/+$/, "")
-}
-
 function sortSessions(now: number) {
   const oneMinuteAgo = now - 60 * 1000
   return (a: Session, b: Session) => {
@@ -29,7 +39,7 @@ function sortSessions(now: number) {
 }
 
 const isRootVisibleSession = (session: Session, directory: string) =>
-  workspaceKey(session.directory) === workspaceKey(directory) && !session.parentID && !session.time?.archived
+  workspacePathKey(session.directory) === workspacePathKey(directory) && !session.parentID && !session.time?.archived
 
 const roots = (store: SessionStore) =>
   (store.session ?? []).filter((session) => isRootVisibleSession(session, store.path.directory))
@@ -73,11 +83,11 @@ export const errorMessage = (err: unknown, fallback: string) => {
 }
 
 export const effectiveWorkspaceOrder = (local: string, dirs: string[], persisted?: string[]) => {
-  const root = workspaceKey(local)
+  const root = workspacePathKey(local)
   const live = new Map<string, string>()
 
   for (const dir of dirs) {
-    const key = workspaceKey(dir)
+    const key = workspacePathKey(dir)
     if (key === root) continue
     if (!live.has(key)) live.set(key, dir)
   }
@@ -86,7 +96,7 @@ export const effectiveWorkspaceOrder = (local: string, dirs: string[], persisted
 
   const result = [local]
   for (const dir of persisted) {
-    const key = workspaceKey(dir)
+    const key = workspacePathKey(dir)
     if (key === root) continue
     const match = live.get(key)
     if (!match) continue
diff --git a/packages/app/src/pages/layout/sidebar-project.tsx b/packages/app/src/pages/layout/sidebar-project.tsx
index 99f1edb74d1b..814d5291e46d 100644
--- a/packages/app/src/pages/layout/sidebar-project.tsx
+++ b/packages/app/src/pages/layout/sidebar-project.tsx
@@ -6,40 +6,41 @@ import { ContextMenu } from "@opencode-ai/ui/context-menu"
 import { HoverCard } from "@opencode-ai/ui/hover-card"
 import { Icon } from "@opencode-ai/ui/icon"
 import { createSortable } from "@thisbeyond/solid-dnd"
+import { type WorkspacePath } from "@/context/file/path"
 import { useLayout, type LocalProject } from "@/context/layout"
 import { useGlobalSync } from "@/context/global-sync"
 import { useLanguage } from "@/context/language"
 import { useNotification } from "@/context/notification"
 import { ProjectIcon, SessionItem, type SessionItemProps } from "./sidebar-items"
-import { childMapByParent, displayName, sortedRootSessions } from "./helpers"
+import { childMapByParent, displayName, projectContains, sortedRootSessions, workspaceEqual } from "./helpers"
 
 export type ProjectSidebarContext = {
-  currentDir: Accessor<string>
+  currentDir: Accessor<WorkspacePath>
   currentProject: Accessor<LocalProject | undefined>
   sidebarOpened: Accessor<boolean>
   sidebarHovering: Accessor<boolean>
-  hoverProject: Accessor<string | undefined>
+  hoverProject: Accessor<WorkspacePath | undefined>
   nav: Accessor<HTMLElement | undefined>
-  onProjectMouseEnter: (worktree: string, event: MouseEvent) => void
-  onProjectMouseLeave: (worktree: string) => void
-  onProjectFocus: (worktree: string) => void
-  navigateToProject: (directory: string) => void
+  onProjectMouseEnter: (worktree: WorkspacePath, event: MouseEvent) => void
+  onProjectMouseLeave: (worktree: WorkspacePath) => void
+  onProjectFocus: (worktree: WorkspacePath) => void
+  navigateToProject: (directory: WorkspacePath) => void
   openSidebar: () => void
-  closeProject: (directory: string) => void
+  closeProject: (directory: WorkspacePath) => void
   showEditProjectDialog: (project: LocalProject) => void
   toggleProjectWorkspaces: (project: LocalProject) => void
   workspacesEnabled: (project: LocalProject) => boolean
-  workspaceIds: (project: LocalProject) => string[]
-  workspaceLabel: (directory: string, branch?: string, projectId?: string) => string
+  workspaceIds: (project: LocalProject) => WorkspacePath[]
+  workspaceLabel: (directory: WorkspacePath, branch?: string, projectId?: string) => string
   sessionProps: Omit<SessionItemProps, "session" | "list" | "slug" | "children" | "mobile" | "dense" | "popover">
   setHoverSession: (id: string | undefined) => void
 }
 
 export const ProjectDragOverlay = (props: {
   projects: Accessor<LocalProject[]>
-  activeProject: Accessor<string | undefined>
+  activeProject: Accessor<WorkspacePath | undefined>
 }): JSX.Element => {
-  const project = createMemo(() => props.projects().find((p) => p.worktree === props.activeProject()))
+  const project = createMemo(() => props.projects().find((p) => workspaceEqual(p.worktree, props.activeProject())))
   return (
     <Show when={project()}>
       {(p) => (
@@ -60,15 +61,15 @@ const ProjectTile = (props: {
   active: Accessor<boolean>
   overlay: Accessor<boolean>
   suppressHover: Accessor<boolean>
-  dirs: Accessor<string[]>
-  onProjectMouseEnter: (worktree: string, event: MouseEvent) => void
-  onProjectMouseLeave: (worktree: string) => void
-  onProjectFocus: (worktree: string) => void
-  navigateToProject: (directory: string) => void
+  dirs: Accessor<WorkspacePath[]>
+  onProjectMouseEnter: (worktree: WorkspacePath, event: MouseEvent) => void
+  onProjectMouseLeave: (worktree: WorkspacePath) => void
+  onProjectFocus: (worktree: WorkspacePath) => void
+  navigateToProject: (directory: WorkspacePath) => void
   showEditProjectDialog: (project: LocalProject) => void
   toggleProjectWorkspaces: (project: LocalProject) => void
   workspacesEnabled: (project: LocalProject) => boolean
-  closeProject: (directory: string) => void
+  closeProject: (directory: WorkspacePath) => void
   setMenu: (value: boolean) => void
   setOpen: (value: boolean) => void
   setSuppressHover: (value: boolean) => void
@@ -191,12 +192,12 @@ const ProjectPreviewPanel = (props: {
   mobile?: boolean
   selected: Accessor<boolean>
   workspaceEnabled: Accessor<boolean>
-  workspaces: Accessor<string[]>
-  label: (directory: string) => string
+  workspaces: Accessor<WorkspacePath[]>
+  label: (directory: WorkspacePath) => string
   projectSessions: Accessor<ReturnType<typeof sortedRootSessions>>
   projectChildren: Accessor<Map<string, string[]>>
-  workspaceSessions: (directory: string) => ReturnType<typeof sortedRootSessions>
-  workspaceChildren: (directory: string) => Map<string, string[]>
+  workspaceSessions: (directory: WorkspacePath) => ReturnType<typeof sortedRootSessions>
+  workspaceChildren: (directory: WorkspacePath) => Map<string, string[]>
   setOpen: (value: boolean) => void
   ctx: ProjectSidebarContext
   language: ReturnType<typeof useLanguage>
@@ -284,7 +285,7 @@ export const SortableProject = (props: {
   const globalSync = useGlobalSync()
   const language = useLanguage()
   const sortable = createSortable(props.project.worktree)
-  const selected = createMemo(() => props.ctx.currentProject()?.worktree === props.project.worktree)
+  const selected = createMemo(() => projectContains(props.project, props.ctx.currentDir()))
   const workspaces = createMemo(() => props.ctx.workspaceIds(props.project).slice(0, 2))
   const workspaceEnabled = createMemo(() => props.ctx.workspacesEnabled(props.project))
   const dirs = createMemo(() => props.ctx.workspaceIds(props.project))
@@ -297,7 +298,9 @@ export const SortableProject = (props: {
   const preview = createMemo(() => !props.mobile && props.ctx.sidebarOpened())
   const overlay = createMemo(() => !props.mobile && !props.ctx.sidebarOpened())
   const active = createMemo(
-    () => state.menu || (preview() ? state.open : overlay() && props.ctx.hoverProject() === props.project.worktree),
+    () =>
+      state.menu ||
+      (preview() ? state.open : overlay() && workspaceEqual(props.ctx.hoverProject(), props.project.worktree)),
   )
 
   createEffect(() => {
@@ -312,10 +315,11 @@ export const SortableProject = (props: {
     setState("open", false)
   })
 
-  const label = (directory: string) => {
+  const label = (directory: WorkspacePath) => {
     const [data] = globalSync.child(directory, { bootstrap: false })
-    const kind =
-      directory === props.project.worktree ? language.t("workspace.type.local") : language.t("workspace.type.sandbox")
+    const kind = workspaceEqual(directory, props.project.worktree)
+      ? language.t("workspace.type.local")
+      : language.t("workspace.type.sandbox")
     const name = props.ctx.workspaceLabel(directory, data.vcs?.branch, props.project.id)
     return `${kind} : ${name}`
   }
@@ -323,11 +327,11 @@ export const SortableProject = (props: {
   const projectStore = createMemo(() => globalSync.child(props.project.worktree, { bootstrap: false })[0])
   const projectSessions = createMemo(() => sortedRootSessions(projectStore(), props.sortNow()))
   const projectChildren = createMemo(() => childMapByParent(projectStore().session))
-  const workspaceSessions = (directory: string) => {
+  const workspaceSessions = (directory: WorkspacePath) => {
     const [data] = globalSync.child(directory, { bootstrap: false })
     return sortedRootSessions(data, props.sortNow())
   }
-  const workspaceChildren = (directory: string) => {
+  const workspaceChildren = (directory: WorkspacePath) => {
     const [data] = globalSync.child(directory, { bootstrap: false })
     return childMapByParent(data.session)
   }
diff --git a/packages/app/src/pages/layout/sidebar-workspace.tsx b/packages/app/src/pages/layout/sidebar-workspace.tsx
index 3bf00ea424d6..4643dd6c02db 100644
--- a/packages/app/src/pages/layout/sidebar-workspace.tsx
+++ b/packages/app/src/pages/layout/sidebar-workspace.tsx
@@ -17,7 +17,7 @@ import { type LocalProject } from "@/context/layout"
 import { useGlobalSync } from "@/context/global-sync"
 import { useLanguage } from "@/context/language"
 import { NewSessionItem, SessionItem, SessionSkeleton } from "./sidebar-items"
-import { childMapByParent, sortedRootSessions, workspaceKey } from "./helpers"
+import { childMapByParent, sortedRootSessions, workspaceEqual } from "./helpers"
 
 type InlineEditorComponent = (props: {
   id: string
@@ -70,8 +70,9 @@ export const WorkspaceDragOverlay = (props: {
     if (!directory) return
 
     const [workspaceStore] = globalSync.child(directory, { bootstrap: false })
-    const kind =
-      directory === project.worktree ? language.t("workspace.type.local") : language.t("workspace.type.sandbox")
+    const kind = workspaceEqual(directory, project.worktree)
+      ? language.t("workspace.type.local")
+      : language.t("workspace.type.sandbox")
     const name = props.workspaceLabel(directory, workspaceStore.vcs?.branch, project.id)
     return `${kind} : ${name}`
   })
@@ -322,8 +323,8 @@ export const SortableWorkspace = (props: {
   const slug = createMemo(() => base64Encode(props.directory))
   const sessions = createMemo(() => sortedRootSessions(workspaceStore, props.sortNow()))
   const children = createMemo(() => childMapByParent(workspaceStore.session))
-  const local = createMemo(() => props.directory === props.project.worktree)
-  const active = createMemo(() => workspaceKey(props.ctx.currentDir()) === workspaceKey(props.directory))
+  const local = createMemo(() => workspaceEqual(props.directory, props.project.worktree))
+  const active = createMemo(() => workspaceEqual(props.ctx.currentDir(), props.directory))
   const workspaceValue = createMemo(() => {
     const branch = workspaceStore.vcs?.branch
     const name = branch ?? getFilename(props.directory)
diff --git a/packages/app/src/pages/session.tsx b/packages/app/src/pages/session.tsx
index 428826f6ad97..e1cf9db839b5 100644
--- a/packages/app/src/pages/session.tsx
+++ b/packages/app/src/pages/session.tsx
@@ -52,6 +52,7 @@ import { useSessionCommands } from "@/pages/session/use-session-commands"
 import { useSessionHashScroll } from "@/pages/session/use-session-hash-scroll"
 import { Identifier } from "@/utils/id"
 import { extractPromptFromParts } from "@/utils/prompt"
+import { sessionDirKey } from "@/utils/session-key"
 import { same } from "@/utils/same"
 import { formatServerError } from "@/utils/server-errors"
 
@@ -358,7 +359,7 @@ export default function Page() {
 
         if (pending.id !== id) return
         layout.handoff.clearTabs()
-        if (pending.dir !== (params.dir ?? "")) return
+        if (pending.dir !== sessionDirKey(params.dir ?? "")) return
 
         const from = workspaceTabs().tabs()
         if (from.all.length === 0 && !from.active) return
@@ -390,10 +391,7 @@ export default function Page() {
   })
   const centered = createMemo(() => isDesktop() && !desktopReviewOpen())
 
-  function normalizeTab(tab: string) {
-    if (!tab.startsWith("file://")) return tab
-    return file.tab(tab)
-  }
+  const normalizeTab = file.normalizeTab
 
   function normalizeTabs(list: string[]) {
     const seen = new Set<string>()
diff --git a/packages/app/src/pages/session/file-tabs.tsx b/packages/app/src/pages/session/file-tabs.tsx
index e3b57fdf2854..47337f976518 100644
--- a/packages/app/src/pages/session/file-tabs.tsx
+++ b/packages/app/src/pages/session/file-tabs.tsx
@@ -12,6 +12,7 @@ import { Tabs } from "@opencode-ai/ui/tabs"
 import { ScrollView } from "@opencode-ai/ui/scroll-view"
 import { showToast } from "@opencode-ai/ui/toast"
 import { selectionFromLines, useFile, type FileSelection, type SelectedLineRange } from "@/context/file"
+import { filePathEqual, type FilePath, type FileTabId } from "@/context/file/path"
 import { useComments } from "@/context/comments"
 import { useLanguage } from "@/context/language"
 import { usePrompt } from "@/context/prompt"
@@ -52,7 +53,7 @@ function FileCommentMenu(props: {
   )
 }
 
-export function FileTabContent(props: { tab: string }) {
+export function FileTabContent(props: { tab: FileTabId }) {
   const file = useFile()
   const comments = useComments()
   const language = useLanguage()
@@ -62,7 +63,7 @@ export function FileTabContent(props: { tab: string }) {
   const activeFileTab = createSessionTabs({
     tabs,
     pathFromTab: file.pathFromTab,
-    normalizeTab: (tab) => (tab.startsWith("file://") ? file.tab(tab) : tab),
+    normalizeTab: file.normalizeTab,
   }).activeFileTab
 
   let scroll: HTMLDivElement | undefined
@@ -79,6 +80,11 @@ export function FileTabContent(props: { tab: string }) {
   }
 
   const path = createMemo(() => file.pathFromTab(props.tab))
+  const label = createMemo(() => {
+    const p = path()
+    if (!p) return ""
+    return file.display(p)
+  })
   const state = createMemo(() => {
     const p = path()
     if (!p) return
@@ -101,7 +107,7 @@ export function FileTabContent(props: { tab: string }) {
   }
 
   const addCommentToContext = (input: {
-    file: string
+    file: FilePath
     selection: SelectedLineRange
     comment: string
     preview?: string
@@ -111,7 +117,7 @@ export function FileTabContent(props: { tab: string }) {
     const preview =
       input.preview ??
       (() => {
-        if (input.file === path()) return selectionPreview(contents(), selection)
+        if (filePathEqual(input.file, path())) return selectionPreview(contents(), selection)
         const source = file.get(input.file)?.content?.content
         if (!source) return undefined
         return selectionPreview(source, selection)
@@ -135,20 +141,20 @@ export function FileTabContent(props: { tab: string }) {
 
   const updateCommentInContext = (input: {
     id: string
-    file: string
+    file: FilePath
     selection: SelectedLineRange
     comment: string
   }) => {
     comments.update(input.file, input.id, input.comment)
     const preview =
-      input.file === path() ? selectionPreview(contents(), selectionFromLines(input.selection)) : undefined
+      filePathEqual(input.file, path()) ? selectionPreview(contents(), selectionFromLines(input.selection)) : undefined
     prompt.context.updateComment(input.file, input.id, {
       comment: input.comment,
       ...(preview ? { preview } : {}),
     })
   }
 
-  const removeCommentFromContext = (input: { id: string; file: string }) => {
+  const removeCommentFromContext = (input: { id: string; file: FilePath }) => {
     comments.remove(input.file, input.id)
     prompt.context.removeComment(input.file, input.id)
   }
@@ -393,7 +399,7 @@ export function FileTabContent(props: { tab: string }) {
         component={fileComponent}
         mode="text"
         file={{
-          name: path() ?? "",
+          name: label(),
           contents: source,
           cacheKey: cacheKey(),
         }}
diff --git a/packages/app/src/pages/session/handoff.ts b/packages/app/src/pages/session/handoff.ts
index 61bdca934292..1122ddbf2201 100644
--- a/packages/app/src/pages/session/handoff.ts
+++ b/packages/app/src/pages/session/handoff.ts
@@ -1,4 +1,5 @@
 import type { SelectedLineRange } from "@/context/file"
+import { normalizeSessionKey } from "@/utils/session-key"
 
 type HandoffSession = {
   prompt: string
@@ -23,11 +24,12 @@ const touch = <K, V>(map: Map<K, V>, key: K, value: V) => {
 }
 
 export const setSessionHandoff = (key: string, patch: Partial<HandoffSession>) => {
-  const prev = store.session.get(key) ?? { prompt: "", files: {} }
-  touch(store.session, key, { ...prev, ...patch })
+  const next = normalizeSessionKey(key)
+  const prev = store.session.get(next) ?? { prompt: "", files: {} }
+  touch(store.session, next, { ...prev, ...patch })
 }
 
-export const getSessionHandoff = (key: string) => store.session.get(key)
+export const getSessionHandoff = (key: string) => store.session.get(normalizeSessionKey(key))
 
 export const setTerminalHandoff = (key: string, value: string[]) => {
   touch(store.terminal, key, value)
diff --git a/packages/app/src/pages/session/helpers.test.ts b/packages/app/src/pages/session/helpers.test.ts
index 047946fc1efc..965eafdb144b 100644
--- a/packages/app/src/pages/session/helpers.test.ts
+++ b/packages/app/src/pages/session/helpers.test.ts
@@ -16,7 +16,7 @@ describe("createOpenReviewFile", () => {
       showAllFiles: () => calls.push("show"),
       tabForPath: (path) => {
         calls.push(`tab:${path}`)
-        return `file://${path}`
+        return `tab:file:${path}`
       },
       openTab: (tab) => calls.push(`open:${tab}`),
       setActive: (tab) => calls.push(`active:${tab}`),
@@ -25,7 +25,7 @@ describe("createOpenReviewFile", () => {
 
     openReviewFile("src/a.ts")
 
-    expect(calls).toEqual(["show", "load:src/a.ts", "tab:src/a.ts", "open:file://src/a.ts", "active:file://src/a.ts"])
+    expect(calls).toEqual(["show", "load:src/a.ts", "tab:src/a.ts", "open:tab:file:src/a.ts", "active:tab:file:src/a.ts"])
   })
 })
 
@@ -35,12 +35,12 @@ describe("createOpenSessionFileTab", () => {
     const openTab = createOpenSessionFileTab({
       normalizeTab: (value) => {
         calls.push(`normalize:${value}`)
-        return `file://${value}`
+        return value.startsWith("file://") ? `tab:file:${value.slice("file://".length)}` : `tab:file:${value}`
       },
       openTab: (tab) => calls.push(`open:${tab}`),
       pathFromTab: (tab) => {
         calls.push(`path:${tab}`)
-        return tab.slice("file://".length)
+        return tab.slice("tab:file:".length)
       },
       loadFile: (path) => calls.push(`load:${path}`),
       openReviewPanel: () => calls.push("review"),
@@ -51,11 +51,11 @@ describe("createOpenSessionFileTab", () => {
 
     expect(calls).toEqual([
       "normalize:src/a.ts",
-      "open:file://src/a.ts",
-      "path:file://src/a.ts",
+      "open:tab:file:src/a.ts",
+      "path:tab:file:src/a.ts",
       "load:src/a.ts",
       "review",
-      "active:file://src/a.ts",
+      "active:tab:file:src/a.ts",
     ])
   })
 })
@@ -101,18 +101,25 @@ describe("createSessionTabs", () => {
     createRoot((dispose) => {
       const [state] = createStore({
         active: undefined as string | undefined,
-        all: ["file://src/a.ts", "context"],
+        all: ["file://src/a.ts", "tab:file:src/a.ts", "context"],
       })
       const tabs = createMemo(() => ({ active: () => state.active, all: () => state.all }))
       const result = createSessionTabs({
         tabs,
-        pathFromTab: (tab) => (tab.startsWith("file://") ? tab.slice("file://".length) : undefined),
-        normalizeTab: (tab) => (tab.startsWith("file://") ? `norm:${tab.slice("file://".length)}` : tab),
+        pathFromTab: (tab) => {
+          if (tab.startsWith("file://")) return tab.slice("file://".length)
+          if (tab.startsWith("tab:file:")) return tab.slice("tab:file:".length)
+        },
+        normalizeTab: (tab) => {
+          if (tab.startsWith("file://")) return `tab:file:${tab.slice("file://".length)}`
+          return tab
+        },
       })
 
-      expect(result.activeTab()).toBe("norm:src/a.ts")
-      expect(result.activeFileTab()).toBe("norm:src/a.ts")
-      expect(result.closableTab()).toBe("norm:src/a.ts")
+      expect(result.openedTabs()).toEqual(["tab:file:src/a.ts"])
+      expect(result.activeTab()).toBe("tab:file:src/a.ts")
+      expect(result.activeFileTab()).toBe("tab:file:src/a.ts")
+      expect(result.closableTab()).toBe("tab:file:src/a.ts")
       dispose()
     })
   })
diff --git a/packages/app/src/pages/session/helpers.ts b/packages/app/src/pages/session/helpers.ts
index c3571f3ffce7..55188afdde1a 100644
--- a/packages/app/src/pages/session/helpers.ts
+++ b/packages/app/src/pages/session/helpers.ts
@@ -1,8 +1,9 @@
 import { batch, createMemo, onCleanup, onMount, type Accessor } from "solid-js"
 import { createStore } from "solid-js/store"
+import { FILE_TAB_PREFIX, type FilePath, type FileTabId } from "@/context/file/path"
 import { same } from "@/utils/same"
 
-const emptyTabs: string[] = []
+const emptyTabs: FileTabId[] = []
 
 type Tabs = {
   active: Accessor<string | undefined>
@@ -11,7 +12,7 @@ type Tabs = {
 
 type TabsInput = {
   tabs: Accessor<Tabs>
-  pathFromTab: (tab: string) => string | undefined
+  pathFromTab: (tab: string) => FilePath | undefined
   normalizeTab: (tab: string) => string
   review?: Accessor<boolean>
   hasReview?: Accessor<boolean>
@@ -22,16 +23,23 @@ export const getSessionKey = (dir: string | undefined, id: string | undefined) =
 export const createSessionTabs = (input: TabsInput) => {
   const review = input.review ?? (() => false)
   const hasReview = input.hasReview ?? (() => false)
+  const fileTab = (tab: string) => {
+    if (!input.pathFromTab(tab)) return
+    const next = input.normalizeTab(tab)
+    if (!next.startsWith(FILE_TAB_PREFIX)) return
+    return next as FileTabId
+  }
   const contextOpen = createMemo(() => input.tabs().active() === "context" || input.tabs().all().includes("context"))
   const openedTabs = createMemo(
     () => {
-      const seen = new Set<string>()
+      const seen = new Set<FileTabId>()
       return input
         .tabs()
         .all()
         .flatMap((tab) => {
           if (tab === "context" || tab === "review") return []
-          const value = input.pathFromTab(tab) ? input.normalizeTab(tab) : tab
+          const value = fileTab(tab)
+          if (!value) return []
           if (seen.has(value)) return []
           seen.add(value)
           return [value]
@@ -44,7 +52,9 @@ export const createSessionTabs = (input: TabsInput) => {
     const active = input.tabs().active()
     if (active === "context") return active
     if (active === "review" && review()) return active
-    if (active && input.pathFromTab(active)) return input.normalizeTab(active)
+
+    const file = active ? fileTab(active) : undefined
+    if (file) return file
 
     const first = openedTabs()[0]
     if (first) return first
@@ -54,12 +64,14 @@ export const createSessionTabs = (input: TabsInput) => {
   })
   const activeFileTab = createMemo(() => {
     const active = activeTab()
+    if (active === "context" || active === "review" || active === "empty") return
     if (!openedTabs().includes(active)) return
     return active
   })
   const closableTab = createMemo(() => {
     const active = activeTab()
     if (active === "context") return active
+    if (active === "review" || active === "empty") return
     if (!openedTabs().includes(active)) return
     return active
   })
@@ -95,12 +107,12 @@ export const focusTerminalById = (id: string) => {
 
 export const createOpenReviewFile = (input: {
   showAllFiles: () => void
-  tabForPath: (path: string) => string
+  tabForPath: (path: FilePath) => FileTabId
   openTab: (tab: string) => void
   setActive: (tab: string) => void
-  loadFile: (path: string) => any | Promise<void>
+  loadFile: (path: FilePath) => any | Promise<void>
 }) => {
-  return (path: string) => {
+  return (path: FilePath) => {
     batch(() => {
       input.showAllFiles()
       const maybePromise = input.loadFile(path)
@@ -118,12 +130,12 @@ export const createOpenReviewFile = (input: {
 export const createOpenSessionFileTab = (input: {
   normalizeTab: (tab: string) => string
   openTab: (tab: string) => void
-  pathFromTab: (tab: string) => string | undefined
-  loadFile: (path: string) => void
+  pathFromTab: (tab: string) => FilePath | undefined
+  loadFile: (path: FilePath) => void
   openReviewPanel: () => void
   setActive: (tab: string) => void
 }) => {
-  return (value: string) => {
+  return (value: FilePath | FileTabId) => {
     const next = input.normalizeTab(value)
     input.openTab(next)
 
diff --git a/packages/app/src/pages/session/review-tab.tsx b/packages/app/src/pages/session/review-tab.tsx
index c073e621472c..2be29b4fd77f 100644
--- a/packages/app/src/pages/session/review-tab.tsx
+++ b/packages/app/src/pages/session/review-tab.tsx
@@ -7,6 +7,7 @@ import type {
   SessionReviewCommentUpdate,
 } from "@opencode-ai/ui/session-review"
 import type { SelectedLineRange } from "@/context/file"
+import type { FilePath, ReviewPath } from "@/context/file/path"
 import { useSDK } from "@/context/sdk"
 import { useLayout } from "@/context/layout"
 import type { LineComment } from "@/context/comments"
@@ -20,15 +21,15 @@ export interface SessionReviewTabProps {
   view: () => ReturnType<ReturnType<typeof useLayout>["view"]>
   diffStyle: DiffStyle
   onDiffStyleChange?: (style: DiffStyle) => void
-  onViewFile?: (file: string) => void
-  onLineComment?: (comment: { file: string; selection: SelectedLineRange; comment: string; preview?: string }) => void
+  onViewFile?: (file: FilePath) => void
+  onLineComment?: (comment: { file: ReviewPath; selection: SelectedLineRange; comment: string; preview?: string }) => void
   onLineCommentUpdate?: (comment: SessionReviewCommentUpdate) => void
   onLineCommentDelete?: (comment: SessionReviewCommentDelete) => void
   lineCommentActions?: SessionReviewCommentActions
   comments?: LineComment[]
-  focusedComment?: { file: string; id: string } | null
-  onFocusedCommentChange?: (focus: { file: string; id: string } | null) => void
-  focusedFile?: string
+  focusedComment?: { file: FilePath; id: string } | null
+  onFocusedCommentChange?: (focus: { file: FilePath; id: string } | null) => void
+  focusedFile?: ReviewPath
   onScrollRef?: (el: HTMLDivElement) => void
   classes?: {
     root?: string
@@ -46,7 +47,7 @@ export function SessionReviewTab(props: SessionReviewTabProps) {
   const sdk = useSDK()
   const layout = useLayout()
 
-  const readFile = async (path: string) => {
+  const readFile = async (path: FilePath) => {
     return sdk.client.file
       .read({ path })
       .then((x) => x.data)
diff --git a/packages/app/src/pages/session/session-layout.ts b/packages/app/src/pages/session/session-layout.ts
index 113411150da4..200df257155a 100644
--- a/packages/app/src/pages/session/session-layout.ts
+++ b/packages/app/src/pages/session/session-layout.ts
@@ -1,11 +1,12 @@
 import { useParams } from "@solidjs/router"
 import { createMemo } from "solid-js"
 import { useLayout } from "@/context/layout"
+import { sessionKey } from "@/utils/session-key"
 
 export const useSessionKey = () => {
   const params = useParams()
-  const sessionKey = createMemo(() => `${params.dir}${params.id ? "/" + params.id : ""}`)
-  return { params, sessionKey }
+  const key = createMemo(() => sessionKey(params.dir ?? "", params.id))
+  return { params, sessionKey: key }
 }
 
 export const useSessionLayout = () => {
diff --git a/packages/app/src/pages/session/session-side-panel.tsx b/packages/app/src/pages/session/session-side-panel.tsx
index 3b8b0c96bfec..beb47d2f973e 100644
--- a/packages/app/src/pages/session/session-side-panel.tsx
+++ b/packages/app/src/pages/session/session-side-panel.tsx
@@ -17,6 +17,7 @@ import { DialogSelectFile } from "@/components/dialog-select-file"
 import { SessionContextTab, SortableTab, FileVisual } from "@/components/session"
 import { useCommand } from "@/context/command"
 import { useFile, type SelectedLineRange } from "@/context/file"
+import { filePathKey, type FilePath, type FilePathKey, type ReviewPath } from "@/context/file/path"
 import { useLanguage } from "@/context/language"
 import { useLayout } from "@/context/layout"
 import { useSync } from "@/context/sync"
@@ -28,8 +29,8 @@ import { useSessionLayout } from "@/pages/session/session-layout"
 
 export function SessionSidePanel(props: {
   reviewPanel: () => JSX.Element
-  activeDiff?: string
-  focusReviewDiff: (path: string) => void
+  activeDiff?: ReviewPath
+  focusReviewDiff: (path: ReviewPath) => void
   reviewSnap: boolean
   size: Sizing
 }) {
@@ -79,11 +80,9 @@ export function SessionSidePanel(props: {
       return "mix" as const
     }
 
-    const normalize = (p: string) => p.replaceAll("\\\\", "/").replace(/\/+$/, "")
-
-    const out = new Map<string, "add" | "del" | "mix">()
+    const out = new Map<FilePathKey, "add" | "del" | "mix">()
     for (const diff of diffs()) {
-      const file = normalize(diff.file)
+      const file = filePathKey(diff.file)
       const kind = diff.status === "added" ? "add" : diff.status === "deleted" ? "del" : "mix"
 
       out.set(file, kind)
@@ -92,7 +91,8 @@ export function SessionSidePanel(props: {
       for (const [idx] of parts.slice(0, -1).entries()) {
         const dir = parts.slice(0, idx + 1).join("/")
         if (!dir) continue
-        out.set(dir, merge(out.get(dir), kind))
+        const key = filePathKey(dir)
+        out.set(key, merge(out.get(key), kind))
       }
     }
     return out
@@ -113,17 +113,12 @@ export function SessionSidePanel(props: {
     return file.tree.children("").length === 0
   })
 
-  const normalizeTab = (tab: string) => {
-    if (!tab.startsWith("file://")) return tab
-    return file.tab(tab)
-  }
-
   const openReviewPanel = () => {
     if (!view().reviewPanel.opened()) view().reviewPanel.open()
   }
 
   const openTab = createOpenSessionFileTab({
-    normalizeTab,
+    normalizeTab: file.normalizeTab,
     openTab: tabs().open,
     pathFromTab: file.pathFromTab,
     loadFile: file.load,
@@ -134,7 +129,7 @@ export function SessionSidePanel(props: {
   const tabState = createSessionTabs({
     tabs,
     pathFromTab: file.pathFromTab,
-    normalizeTab,
+    normalizeTab: file.normalizeTab,
     review: reviewTab,
     hasReview,
   })
@@ -185,7 +180,7 @@ export function SessionSidePanel(props: {
     setSessionHandoff(sessionKey(), {
       files: tabs()
         .all()
-        .reduce<Record<string, SelectedLineRange | null>>((acc, tab) => {
+        .reduce<Record<FilePath, SelectedLineRange | null>>((acc, tab) => {
           const path = file.pathFromTab(tab)
           if (!path) return acc
 
diff --git a/packages/app/src/pages/session/use-session-commands.tsx b/packages/app/src/pages/session/use-session-commands.tsx
index 1a2e777f5229..91caa0e63463 100644
--- a/packages/app/src/pages/session/use-session-commands.tsx
+++ b/packages/app/src/pages/session/use-session-commands.tsx
@@ -61,14 +61,10 @@ export const useSessionCommands = (actions: SessionCommandContext) => {
     if (!id) return false
     return Math.max(info()?.summary?.files ?? 0, (sync.data.session_diff[id] ?? []).length) > 0
   }
-  const normalizeTab = (tab: string) => {
-    if (!tab.startsWith("file://")) return tab
-    return file.tab(tab)
-  }
   const tabState = createSessionTabs({
     tabs,
     pathFromTab: file.pathFromTab,
-    normalizeTab,
+    normalizeTab: file.normalizeTab,
     review: actions.review,
     hasReview,
   })
diff --git a/packages/app/src/utils/persist-path.test.ts b/packages/app/src/utils/persist-path.test.ts
new file mode 100644
index 000000000000..5565433918af
--- /dev/null
+++ b/packages/app/src/utils/persist-path.test.ts
@@ -0,0 +1,155 @@
+import { describe, expect, test } from "bun:test"
+import { base64Encode } from "@opencode-ai/util/encode"
+import { migrateLayoutPageState, migrateLayoutPaths, migrateServerState } from "./persist-path"
+
+describe("migrateLayoutPaths", () => {
+  test("converts legacy sidebar flags and normalizes workspace keys", () => {
+    expect(migrateLayoutPaths({ sidebar: { workspaces: true } })).toEqual({
+      sidebar: {
+        workspaces: {},
+        workspacesDefault: true,
+      },
+    })
+
+    expect(
+      migrateLayoutPaths({
+        sidebar: {
+          workspaces: {
+            "C:\\Repo\\": true,
+            "c:/repo": false,
+            "/tmp/demo///": true,
+          },
+        },
+      }),
+    ).toEqual({
+      sidebar: {
+        workspaces: {
+          "c:/repo": false,
+          "/tmp/demo": true,
+        },
+      },
+    })
+  })
+
+  test("migrates session-keyed maps and handoff directory aliases", () => {
+    const legacy = base64Encode("C:\\Repo\\")
+    const next = base64Encode("c:/repo")
+
+    expect(
+      migrateLayoutPaths({
+        sidebar: {
+          workspaces: {},
+        },
+        sessionTabs: {
+          [legacy]: { all: ["file://src\\a.ts"], active: "file://src\\a.ts" },
+          [next]: { all: ["review"], active: "review" },
+        },
+        sessionView: {
+          [`${legacy}/one`]: { scroll: { "file://src\\a.ts": { x: 1, y: 2 } } },
+          [`${next}/one`]: { scroll: { review: { x: 3, y: 4 } }, pendingMessage: "m", pendingMessageAt: 2 },
+        },
+        handoff: {
+          tabs: {
+            dir: legacy,
+            id: "one",
+            at: 5,
+          },
+        },
+      }),
+    ).toEqual({
+      sidebar: {
+        workspaces: {},
+      },
+      sessionTabs: {
+        [next]: { all: ["review", "tab:file:src/a.ts"], active: "review" },
+      },
+      sessionView: {
+        [`${next}/one`]: {
+          scroll: {
+            review: { x: 3, y: 4 },
+            "tab:file:src/a.ts": { x: 1, y: 2 },
+          },
+          pendingMessage: "m",
+          pendingMessageAt: 2,
+        },
+      },
+      handoff: {
+        tabs: {
+          dir: next,
+          id: "one",
+          at: 5,
+        },
+      },
+    })
+  })
+})
+
+describe("migrateLayoutPageState", () => {
+  test("keeps path values while normalizing workspace keys", () => {
+    expect(
+      migrateLayoutPageState({
+        activeProject: "C:\\Repo\\",
+        activeWorkspace: "C:/Repo/Feature/",
+        lastProjectSession: {
+          "C:\\Repo\\": { directory: "C:/Repo/Feature/", id: "old", at: 1 },
+          "c:/repo": { directory: "c:\\repo\\feature\\", id: "new", at: 2 },
+        },
+        workspaceOrder: {
+          "C:\\Repo\\": ["C:/Repo", "C:/Repo/Feature/", "c:\\repo\\feature\\", "c:\\repo\\other\\"],
+        },
+        workspaceName: {
+          "C:\\Repo\\Feature\\": "feature",
+          "c:/repo/feature": "feature latest",
+        },
+        workspaceExpanded: {
+          "C:\\Repo\\": true,
+          "c:/repo": false,
+        },
+      }),
+    ).toEqual({
+      activeProject: "C:\\Repo\\",
+      activeWorkspace: "C:/Repo/Feature/",
+      lastProjectSession: {
+        "c:/repo": { directory: "c:\\repo\\feature\\", id: "new", at: 2 },
+      },
+      workspaceOrder: {
+        "c:/repo": ["C:/Repo/Feature/", "c:\\repo\\other\\"],
+      },
+      workspaceName: {
+        "c:/repo/feature": "feature latest",
+      },
+      workspaceExpanded: {
+        "c:/repo": false,
+      },
+    })
+  })
+})
+
+describe("migrateServerState", () => {
+  test("keeps persisted server path values while deduping by key", () => {
+    expect(
+      migrateServerState({
+        projects: {
+          local: [
+            { worktree: "C:\\Repo\\", expanded: false },
+            { worktree: "c:/repo", expanded: true },
+            { worktree: "/tmp/demo///", expanded: true },
+          ],
+        },
+        lastProject: {
+          local: "C:/Repo/",
+        },
+      }),
+    ).toEqual({
+      projects: {
+        local: [
+          { worktree: "C:\\Repo\\", expanded: true },
+          { worktree: "/tmp/demo///", expanded: true },
+        ],
+      },
+      lastProject: {
+        local: "C:/Repo/",
+      },
+    })
+  })
+})
diff --git a/packages/app/src/utils/persist-path.ts b/packages/app/src/utils/persist-path.ts
new file mode 100644
index 000000000000..0e959dda9506
--- /dev/null
+++ b/packages/app/src/utils/persist-path.ts
@@ -0,0 +1,336 @@
+import { workspacePathKey, type WorkspaceKey, type WorkspacePath } from "@/context/file/path"
+import { normalizeSessionKey, sessionDirKey, sessionPathHelpers } from "@/utils/session-key"
+
+const record = (value: unknown): value is Record<string, unknown> =>
+  typeof value === "object" && value !== null && !Array.isArray(value)
+
+const text = (value: unknown) => (typeof value === "string" ? value : undefined)
+
+const num = (value: unknown) => (typeof value === "number" && Number.isFinite(value) ? value : undefined)
+
+const flag = (value: unknown) => (typeof value === "boolean" ? value : undefined)
+
+function paths(value: unknown, skip?: string) {
+  if (!Array.isArray(value)) return
+
+  const omit = skip ? workspacePathKey(skip) : undefined
+  const seen = new Set<string>()
+  const out: string[] = []
+
+  for (const item of value) {
+    const cur = text(item)
+    if (!cur) continue
+
+    const id = workspacePathKey(cur)
+    if (id === omit || seen.has(id)) continue
+    seen.add(id)
+    out.push(cur)
+  }
+
+  return out
+}
+
+function byKey<T>(
+  value: unknown,
+  move: (value: unknown, key: WorkspaceKey) => T | undefined,
+  merge?: (prev: T, next: T) => T,
+) {
+  if (!record(value)) return
+
+  const out: Record<WorkspaceKey, T> = {}
+  for (const [name, item] of Object.entries(value)) {
+    const id = workspacePathKey(name)
+    const next = move(item, id)
+    if (next === undefined) continue
+
+    const prev = out[id]
+    out[id] = prev !== undefined && merge ? merge(prev, next) : next
+  }
+
+  return out
+}
+
+function bySession<T>(value: unknown, move: (value: unknown, key: string) => T | undefined, merge?: (prev: T, next: T) => T) {
+  if (!record(value)) return
+
+  const out: Record<string, T> = {}
+  for (const [name, item] of Object.entries(value)) {
+    const key = normalizeSessionKey(name)
+    const next = move(item, key)
+    if (next === undefined) continue
+
+    const prev = out[key]
+    out[key] = prev !== undefined && merge ? merge(prev, next) : next
+  }
+
+  return out
+}
+
+function list(value: readonly string[]) {
+  const seen = new Set<string>()
+  const out: string[] = []
+
+  for (const item of value) {
+    if (seen.has(item)) continue
+    seen.add(item)
+    out.push(item)
+  }
+
+  return out
+}
+
+function tabs(value: readonly string[], path: ReturnType<typeof sessionPathHelpers>) {
+  if (!path) return list(value)
+
+  const seen = new Set<string>()
+  const out: string[] = []
+
+  for (const item of value) {
+    const next = path.normalizeTab(item)
+    if (seen.has(next)) continue
+    seen.add(next)
+    out.push(next)
+  }
+
+  return out
+}
+
+function scroll(value: unknown, path: ReturnType<typeof sessionPathHelpers>) {
+  if (!record(value)) return {}
+
+  if (!path) return value
+
+  return Object.fromEntries(Object.entries(value).map(([name, item]) => [path.normalizeTab(name), item]))
+}
+
+type Route = Record<string, unknown> & {
+  directory: WorkspacePath
+  id: string
+  at?: number
+}
+
+function route(value: unknown): Route | undefined {
+  if (!record(value)) return
+
+  const directory = text(value.directory)
+  const id = text(value.id)
+  if (!directory || !id) return
+
+  const at = num(value.at)
+  return {
+    ...value,
+    directory,
+    id,
+    ...(at !== undefined ? { at } : {}),
+  }
+}
+
+type Project = Record<string, unknown> & {
+  worktree: WorkspacePath
+  expanded: boolean
+}
+
+type SessionTabs = {
+  active?: string
+  all: string[]
+}
+
+type SessionView = Record<string, unknown> & {
+  scroll: Record<string, unknown>
+  reviewOpen?: string[]
+  pendingMessage?: string
+  pendingMessageAt?: number
+}
+
+function project(value: unknown): Project | undefined {
+  if (!record(value)) return
+
+  const worktree = text(value.worktree)
+  if (!worktree) return
+
+  return {
+    ...value,
+    worktree,
+    expanded: flag(value.expanded) ?? false,
+  }
+}
+
+function projects(value: unknown) {
+  if (!Array.isArray(value)) return
+
+  const seen = new Map<string, number>()
+  const out: Project[] = []
+
+  for (const item of value) {
+    const next = project(item)
+    if (!next) continue
+
+    const id = workspacePathKey(next.worktree)
+    const at = seen.get(id)
+    if (at === undefined) {
+      seen.set(id, out.length)
+      out.push(next)
+      continue
+    }
+
+    out[at] = { ...out[at], expanded: out[at].expanded || next.expanded }
+  }
+
+  return out
+}
+
+function sessionTabs(value: unknown, key: string): SessionTabs | undefined {
+  if (!record(value)) return
+  if (!Array.isArray(value.all)) return
+
+  const path = sessionPathHelpers(key)
+  const all = tabs(value.all.filter((item): item is string => typeof item === "string"), path)
+  const active = text(value.active)
+
+  return {
+    all,
+    active: active ? path?.normalizeTab(active) ?? active : undefined,
+  }
+}
+
+function mergeSessionTabs(prev: SessionTabs, next: SessionTabs): SessionTabs {
+  return {
+    all: list([...next.all, ...prev.all]),
+    active: next.active ?? prev.active,
+  }
+}
+
+function sessionView(value: unknown, key: string): SessionView | undefined {
+  if (!record(value)) return
+  const path = sessionPathHelpers(key)
+
+  return {
+    ...value,
+    scroll: scroll(value.scroll, path),
+    ...(Array.isArray(value.reviewOpen)
+      ? { reviewOpen: value.reviewOpen.filter((item): item is string => typeof item === "string") }
+      : {}),
+    ...(text(value.pendingMessage) ? { pendingMessage: text(value.pendingMessage) } : {}),
+    ...(num(value.pendingMessageAt) !== undefined ? { pendingMessageAt: num(value.pendingMessageAt) } : {}),
+  }
+}
+
+function mergeSessionView(prev: SessionView, next: SessionView): SessionView {
+  const pending = (next.pendingMessageAt ?? -Infinity) >= (prev.pendingMessageAt ?? -Infinity)
+  return {
+    ...prev,
+    ...next,
+    scroll: { ...prev.scroll, ...next.scroll },
+    ...(next.reviewOpen ? { reviewOpen: next.reviewOpen } : prev.reviewOpen ? { reviewOpen: prev.reviewOpen } : {}),
+    ...(pending
+      ? {
+          ...(next.pendingMessage ? { pendingMessage: next.pendingMessage } : prev.pendingMessage ? { pendingMessage: prev.pendingMessage } : {}),
+          ...(next.pendingMessageAt !== undefined
+            ? { pendingMessageAt: next.pendingMessageAt }
+            : prev.pendingMessageAt !== undefined
+              ? { pendingMessageAt: prev.pendingMessageAt }
+              : {}),
+        }
+      : {
+          ...(prev.pendingMessage ? { pendingMessage: prev.pendingMessage } : {}),
+          ...(prev.pendingMessageAt !== undefined ? { pendingMessageAt: prev.pendingMessageAt } : {}),
+        }),
+  }
+}
+
+export function migrateLayoutPaths(value: unknown) {
+  if (!record(value)) return value
+
+  const sidebar = value.sidebar
+  const nextSidebar = (() => {
+    if (!record(sidebar)) return sidebar
+    if (typeof sidebar.workspaces === "boolean") {
+      return {
+        ...sidebar,
+        workspaces: {},
+        workspacesDefault: sidebar.workspaces,
+      }
+    }
+
+    const workspaces = byKey(sidebar.workspaces, (item) => flag(item))
+    if (!workspaces) return sidebar
+    return {
+      ...sidebar,
+      workspaces,
+    }
+  })()
+  const sessionTabsMap = bySession(value.sessionTabs, (item, key) => sessionTabs(item, key), mergeSessionTabs)
+  const sessionViewMap = bySession(value.sessionView, (item, key) => sessionView(item, key), mergeSessionView)
+  const handoff = (() => {
+    if (!record(value.handoff)) return value.handoff
+    if (!record(value.handoff.tabs)) return value.handoff
+    const dir = text(value.handoff.tabs.dir)
+    if (!dir) return value.handoff
+    return {
+      ...value.handoff,
+      tabs: {
+        ...value.handoff.tabs,
+        dir: sessionDirKey(dir),
+      },
+    }
+  })()
+
+  if (nextSidebar === sidebar && !sessionTabsMap && !sessionViewMap && handoff === value.handoff) return value
+
+  return {
+    ...value,
+    ...(nextSidebar !== sidebar ? { sidebar: nextSidebar } : {}),
+    ...(sessionTabsMap ? { sessionTabs: sessionTabsMap } : {}),
+    ...(sessionViewMap ? { sessionView: sessionViewMap } : {}),
+    ...(handoff !== value.handoff ? { handoff } : {}),
+  }
+}
+
+export function migrateLayoutPageState(value: unknown) {
+  if (!record(value)) return value
+
+  const lastProjectSession = byKey(value.lastProjectSession, (item) => route(item), (prev, next) => {
+    if ((next.at ?? -Infinity) >= (prev.at ?? -Infinity)) return next
+    return prev
+  })
+
+  const workspaceOrder = byKey(value.workspaceOrder, (item, id) => paths(item, id) ?? [])
+  const workspaceName = byKey(value.workspaceName, (item) => text(item))
+  const workspaceExpanded = byKey(value.workspaceExpanded, (item) => flag(item))
+
+  return {
+    ...value,
+    ...(lastProjectSession ? { lastProjectSession } : {}),
+    ...(workspaceOrder ? { workspaceOrder } : {}),
+    ...(workspaceName ? { workspaceName } : {}),
+    ...(workspaceExpanded ? { workspaceExpanded } : {}),
+  }
+}
+
+export function migrateServerState(value: unknown) {
+  if (!record(value)) return value
+
+  const lastProject = record(value.lastProject)
+    ? Object.fromEntries(
+        Object.entries(value.lastProject).flatMap(([key, item]) => {
+          const next = text(item)
+          if (!next) return []
+          return [[key, next] as const]
+        }),
+      )
+    : undefined
+
+  const projectsByServer = record(value.projects)
+    ? Object.fromEntries(
+        Object.entries(value.projects).map(([key, item]) => {
+          return [key, projects(item) ?? []] as const
+        }),
+      )
+    : undefined
+
+  return {
+    ...value,
+    ...(lastProject ? { lastProject } : {}),
+    ...(projectsByServer ? { projects: projectsByServer } : {}),
+  }
+}
diff --git a/packages/app/src/utils/persist.test.ts b/packages/app/src/utils/persist.test.ts
index 673acd224d24..cda017729c5b 100644
--- a/packages/app/src/utils/persist.test.ts
+++ b/packages/app/src/utils/persist.test.ts
@@ -1,6 +1,8 @@
 import { beforeAll, beforeEach, describe, expect, mock, test } from "bun:test"
 
 type PersistTestingType = typeof import("./persist").PersistTesting
+type PersistType = typeof import("./persist").Persist
+type RemovePersistedType = typeof import("./persist").removePersisted
 
 class MemoryStorage implements Storage {
   private values = new Map<string, string>()
@@ -45,6 +47,8 @@ class MemoryStorage implements Storage {
 const storage = new MemoryStorage()
 
 let persistTesting: PersistTestingType
+let Persist: PersistType
+let removePersisted: RemovePersistedType
 
 beforeAll(async () => {
   mock.module("@/context/platform", () => ({
@@ -53,6 +57,8 @@ beforeAll(async () => {
 
   const mod = await import("./persist")
   persistTesting = mod.PersistTesting
+  Persist = mod.Persist
+  removePersisted = mod.removePersisted
 })
 
 beforeEach(() => {
@@ -112,4 +118,53 @@ describe("persist localStorage resilience", () => {
     expect(result.endsWith(".dat")).toBeTrue()
     expect(/[:\\/]/.test(result)).toBeFalse()
   })
+
+  test("workspace storage collapses equivalent directory spellings", () => {
+    expect(persistTesting.workspaceStorage("C:\\Users\\foo\\")).toBe(
+      persistTesting.workspaceStorage("c:/users/foo"),
+    )
+    expect(persistTesting.workspaceLegacyStorage("C:\\Users\\foo\\").length).toBeGreaterThan(1)
+  })
+
+  test("workspace legacy storage probes slash and drive-letter variants", () => {
+    const names = persistTesting.workspaceLegacyStorage("C:/Users/foo")
+
+    expect(names).toContain(persistTesting.workspaceStorageName("C:\\Users\\foo"))
+    expect(names).toContain(persistTesting.workspaceStorageName("c:/Users/foo/"))
+  })
+
+  test("legacy scoped keys cover equivalent directory aliases", () => {
+    expect(persistTesting.legacyScoped("C:/Users/foo", "s1", "file", "v1")).toEqual(
+      expect.arrayContaining([
+        "C:/Users/foo/file/s1.v1",
+        "C:\\Users\\foo/file/s1.v1",
+        "c:/users/foo/file/s1.v1",
+      ]),
+    )
+  })
+
+  test("removePersisted clears current and legacy aliases across lookup stores", () => {
+    const dir = "C:/Users/foo"
+    const legacy = persistTesting.legacyScoped(dir, "s1", "terminal", "v1")
+    const target = {
+      ...Persist.workspace(dir, "terminal"),
+      legacy,
+    }
+
+    const current = persistTesting.workspaceStorage(dir)
+    const extra = persistTesting.workspaceLegacyStorage(dir)[0]!
+    const direct = persistTesting.localStorageDirect()
+
+    persistTesting.localStorageWithPrefix(current).setItem("workspace:terminal", '{"current":1}')
+    persistTesting.localStorageWithPrefix(extra).setItem(legacy[0]!, '{"extra":1}')
+    direct.setItem("workspace:terminal", '{"legacy-current":1}')
+    direct.setItem(legacy[1]!, '{"legacy":1}')
+
+    removePersisted(target)
+
+    expect(persistTesting.localStorageWithPrefix(current).getItem("workspace:terminal")).toBeNull()
+    expect(persistTesting.localStorageWithPrefix(extra).getItem(legacy[0]!)).toBeNull()
+    expect(direct.getItem("workspace:terminal")).toBeNull()
+    expect(direct.getItem(legacy[1]!)).toBeNull()
+  })
 })
diff --git a/packages/app/src/utils/persist.ts b/packages/app/src/utils/persist.ts
index 3dcbeb7d3677..c3b73b830d28 100644
--- a/packages/app/src/utils/persist.ts
+++ b/packages/app/src/utils/persist.ts
@@ -1,4 +1,5 @@
 import { Platform, usePlatform } from "@/context/platform"
+import { workspacePathKey } from "@/context/file/path"
 import { makePersisted, type AsyncStorage, type SyncStorage } from "@solid-primitives/storage"
 import { checksum } from "@opencode-ai/util/encode"
 import { createResource, type Accessor } from "solid-js"
@@ -16,6 +17,7 @@ type PersistTarget = {
   storage?: string
   key: string
   legacy?: string[]
+  legacyStorage?: string[]
   migrate?: (value: unknown) => unknown
 }
 
@@ -31,6 +33,13 @@ type CacheEntry = { value: string; bytes: number }
 const cache = new Map<string, CacheEntry>()
 const cacheTotal = { bytes: 0 }
 
+type PersistStore = SyncStorage | AsyncStorage
+type PersistStores = {
+  current: PersistStore
+  legacy?: PersistStore
+  extra: PersistStore[]
+}
+
 function cacheDelete(key: string) {
   const entry = cache.get(key)
   if (!entry) return
@@ -208,12 +217,86 @@ function normalize(defaults: unknown, raw: string, migrate?: (value: unknown) =>
   return JSON.stringify(merged)
 }
 
-function workspaceStorage(dir: string) {
+function workspaceDirectory(dir: string) {
+  return workspacePathKey(dir)
+}
+
+function trimDir(dir: string) {
+  if (!dir) return dir
+  if (/^[A-Za-z]:[\\/]?$/.test(dir)) return dir.slice(0, 2)
+  const trimmed = dir.replace(/[\\/]+$/, "")
+  return trimmed || dir
+}
+
+function windowsPath(dir: string) {
+  return /^[A-Za-z]:/.test(dir) || /^[\\/]{2}/.test(dir) || dir.includes("\\")
+}
+
+function driveLetters(dir: string) {
+  if (!/^[A-Za-z]:/.test(dir)) return [dir]
+  return [dir[0].toLowerCase() + dir.slice(1), dir[0].toUpperCase() + dir.slice(1)]
+}
+
+function pathForms(dir: string) {
+  const base = trimDir(dir)
+  if (!base) return []
+  if (!windowsPath(base)) return [base]
+  return [base, base.replace(/\\/g, "/"), base.replace(/\//g, "\\")]
+}
+
+function withTrailing(dir: string) {
+  if (!dir) return []
+  if (!windowsPath(dir)) return dir === "/" ? [dir] : [dir, `${dir}/`]
+  if (/^[A-Za-z]:$/.test(dir)) return [`${dir}/`, `${dir}\\`]
+  if (/^[\\/]{2}[^\\/]+[\\/][^\\/]+$/.test(dir)) return [dir, `${dir}/`, `${dir}\\`]
+  const tail = dir.includes("\\") ? "\\" : "/"
+  return [dir, `${dir}${tail}`]
+}
+
+function workspaceDirectories(dir: string) {
+  const seen = new Set<string>()
+
+  const add = (value: string) => {
+    if (!value) return
+    seen.add(value)
+  }
+
+  for (const value of [dir, workspaceDirectory(dir)]) {
+    for (const form of pathForms(value)) {
+      for (const letter of driveLetters(form)) {
+        for (const item of withTrailing(letter)) {
+          add(item)
+        }
+      }
+    }
+  }
+
+  return Array.from(seen)
+}
+
+function workspaceStorageName(dir: string) {
   const head = (dir.slice(0, 12) || "workspace").replace(/[^a-zA-Z0-9._-]/g, "-")
   const sum = checksum(dir) ?? "0"
   return `opencode.workspace.${head}.${sum}.dat`
 }
 
+function workspaceStorage(dir: string) {
+  return workspaceStorageName(workspaceDirectory(dir))
+}
+
+function workspaceLegacyStorage(dir: string) {
+  const current = workspaceStorage(dir)
+  return workspaceDirectories(dir)
+    .map(workspaceStorageName)
+    .filter((item, index, list) => item !== current && list.indexOf(item) === index)
+}
+
+function legacyScoped(dir: string, session: string | undefined, key: string, version: string) {
+  return workspaceDirectories(dir)
+    .map((root) => `${root}/${key}${session ? "/" + session : ""}.${version}`)
+    .filter((item, index, list) => list.indexOf(item) === index)
+}
+
 function localStorageWithPrefix(prefix: string): SyncStorage {
   const base = `${prefix}:`
   const scope = `prefix:${prefix}`
@@ -301,22 +384,63 @@ function localStorageDirect(): SyncStorage {
   }
 }
 
+function stores(config: PersistTarget, platform?: Platform): PersistStores {
+  const isDesktop = platform?.platform === "desktop" && !!platform.storage
+
+  return {
+    current: (() => {
+      if (isDesktop) return platform.storage!(config.storage)
+      if (!config.storage) return localStorageDirect()
+      return localStorageWithPrefix(config.storage)
+    })(),
+    legacy: (() => {
+      if (!isDesktop) return localStorageDirect()
+      if (!config.storage) return platform.storage!()
+      return platform.storage!(LEGACY_STORAGE)
+    })(),
+    extra: (() => {
+      if (!config.legacyStorage?.length) return []
+      if (!isDesktop) return config.legacyStorage.map((storage) => localStorageWithPrefix(storage))
+      return config.legacyStorage.flatMap((storage) => {
+        const item = platform.storage!(storage)
+        return item ? [item] : []
+      })
+    })(),
+  }
+}
+
 export const PersistTesting = {
+  legacyScoped,
   localStorageDirect,
   localStorageWithPrefix,
   normalize,
+  workspaceDirectory,
+  workspaceDirectories,
   workspaceStorage,
+  workspaceStorageName,
+  workspaceLegacyStorage,
 }
 
 export const Persist = {
+  legacyScoped,
   global(key: string, legacy?: string[]): PersistTarget {
     return { storage: GLOBAL_STORAGE, key, legacy }
   },
   workspace(dir: string, key: string, legacy?: string[]): PersistTarget {
-    return { storage: workspaceStorage(dir), key: `workspace:${key}`, legacy }
+    return {
+      storage: workspaceStorage(dir),
+      key: `workspace:${key}`,
+      legacy,
+      legacyStorage: workspaceLegacyStorage(dir),
+    }
   },
   session(dir: string, session: string, key: string, legacy?: string[]): PersistTarget {
-    return { storage: workspaceStorage(dir), key: `session:${session}:${key}`, legacy }
+    return {
+      storage: workspaceStorage(dir),
+      key: `session:${session}:${key}`,
+      legacy,
+      legacyStorage: workspaceLegacyStorage(dir),
+    }
   },
   scoped(dir: string, session: string | undefined, key: string, legacy?: string[]): PersistTarget {
     if (session) return Persist.session(dir, session, key, legacy)
@@ -324,19 +448,18 @@ export const Persist = {
   },
 }
 
-export function removePersisted(target: { storage?: string; key: string }, platform?: Platform) {
-  const isDesktop = platform?.platform === "desktop" && !!platform.storage
+export function removePersisted(target: PersistTarget, platform?: Platform) {
+  const keys = [target.key, ...(target.legacy ?? [])]
+  const seen = new Set<PersistStore>()
+  const all = stores(target, platform)
 
-  if (isDesktop) {
-    return platform.storage?.(target.storage)?.removeItem(target.key)
-  }
-
-  if (!target.storage) {
-    localStorageDirect().removeItem(target.key)
-    return
+  for (const store of [all.current, all.legacy, ...all.extra]) {
+    if (!store || seen.has(store)) continue
+    seen.add(store)
+    for (const key of keys) {
+      store.removeItem(key)
+    }
   }
-
-  localStorageWithPrefix(target.storage).removeItem(target.key)
 }
 
 export function persisted<T>(
@@ -350,49 +473,42 @@ export function persisted<T>(
   const legacy = config.legacy ?? []
 
   const isDesktop = platform.platform === "desktop" && !!platform.storage
-
-  const currentStorage = (() => {
-    if (isDesktop) return platform.storage?.(config.storage)
-    if (!config.storage) return localStorageDirect()
-    return localStorageWithPrefix(config.storage)
-  })()
-
-  const legacyStorage = (() => {
-    if (!isDesktop) return localStorageDirect()
-    if (!config.storage) return platform.storage?.()
-    return platform.storage?.(LEGACY_STORAGE)
-  })()
+  const all = stores(config, platform)
 
   const storage = (() => {
     if (!isDesktop) {
-      const current = currentStorage as SyncStorage
-      const legacyStore = legacyStorage as SyncStorage
+      const current = all.current as SyncStorage
+      const legacyStore = all.legacy as SyncStorage
+      const extra = all.extra as SyncStorage[]
 
       const api: SyncStorage = {
         getItem: (key) => {
-          const raw = current.getItem(key)
-          if (raw !== null) {
-            const next = normalize(defaults, raw, config.migrate)
-            if (next === undefined) {
-              current.removeItem(key)
-              return null
-            }
-            if (raw !== next) current.setItem(key, next)
-            return next
+          const sources = [{ storage: current, keys: [key, ...legacy] }]
+          if (legacyStore) sources.push({ storage: legacyStore, keys: [key, ...legacy] })
+          for (const storage of extra) {
+            sources.push({ storage, keys: [key, ...legacy] })
           }
 
-          for (const legacyKey of legacy) {
-            const legacyRaw = legacyStore.getItem(legacyKey)
-            if (legacyRaw === null) continue
-
-            const next = normalize(defaults, legacyRaw, config.migrate)
-            if (next === undefined) {
-              legacyStore.removeItem(legacyKey)
-              continue
+          for (const source of sources) {
+            for (const name of source.keys) {
+              const raw = source.storage.getItem(name)
+              if (raw === null) continue
+
+              const next = normalize(defaults, raw, config.migrate)
+              if (next === undefined) {
+                source.storage.removeItem(name)
+                continue
+              }
+
+              if (source.storage !== current || name !== key) {
+                current.setItem(key, next)
+                source.storage.removeItem(name)
+                return next
+              }
+
+              if (raw !== next) current.setItem(key, next)
+              return next
             }
-            current.setItem(key, next)
-            legacyStore.removeItem(legacyKey)
-            return next
           }
 
           return null
@@ -408,36 +524,38 @@ export function persisted<T>(
       return api
     }
 
-    const current = currentStorage as AsyncStorage
-    const legacyStore = legacyStorage as AsyncStorage | undefined
+    const current = all.current as AsyncStorage
+    const legacyStore = all.legacy as AsyncStorage | undefined
+    const extra = all.extra as AsyncStorage[]
 
     const api: AsyncStorage = {
       getItem: async (key) => {
-        const raw = await current.getItem(key)
-        if (raw !== null) {
-          const next = normalize(defaults, raw, config.migrate)
-          if (next === undefined) {
-            await current.removeItem(key).catch(() => undefined)
-            return null
-          }
-          if (raw !== next) await current.setItem(key, next)
-          return next
+        const sources = [{ storage: current, keys: [key, ...legacy] }]
+        if (legacyStore) sources.push({ storage: legacyStore, keys: [key, ...legacy] })
+        for (const storage of extra) {
+          sources.push({ storage, keys: [key, ...legacy] })
         }
 
-        if (!legacyStore) return null
+        for (const source of sources) {
+          for (const name of source.keys) {
+            const raw = await source.storage.getItem(name)
+            if (raw === null) continue
+
+            const next = normalize(defaults, raw, config.migrate)
+            if (next === undefined) {
+              await source.storage.removeItem(name).catch(() => undefined)
+              continue
+            }
 
-        for (const legacyKey of legacy) {
-          const legacyRaw = await legacyStore.getItem(legacyKey)
-          if (legacyRaw === null) continue
+            if (source.storage !== current || name !== key) {
+              await current.setItem(key, next)
+              await source.storage.removeItem(name).catch(() => undefined)
+              return next
+            }
 
-          const next = normalize(defaults, legacyRaw, config.migrate)
-          if (next === undefined) {
-            await legacyStore.removeItem(legacyKey).catch(() => undefined)
-            continue
+            if (raw !== next) await current.setItem(key, next)
+            return next
           }
-          await current.setItem(key, next)
-          await legacyStore.removeItem(legacyKey)
-          return next
         }
 
         return null
diff --git a/packages/app/src/utils/prompt.test.ts b/packages/app/src/utils/prompt.test.ts
new file mode 100644
index 000000000000..669365205cc0
--- /dev/null
+++ b/packages/app/src/utils/prompt.test.ts
@@ -0,0 +1,80 @@
+import { describe, expect, test } from "bun:test"
+import type { Part } from "@opencode-ai/sdk/v2"
+import { extractPromptFromParts } from "./prompt"
+
+describe("extractPromptFromParts", () => {
+  test("restores workspace-relative file paths across windows path variants", () => {
+    const parts: Part[] = [
+      {
+        id: "text_1",
+        sessionID: "ses_1",
+        messageID: "msg_1",
+        type: "text",
+        text: "Check @src\\app.ts",
+      },
+      {
+        id: "file_1",
+        sessionID: "ses_1",
+        messageID: "msg_1",
+        type: "file",
+        mime: "text/plain",
+        url: "file:///C:/Repo/src/app.ts?start=3&end=5",
+        source: {
+          type: "file",
+          path: "C:\\Repo\\src\\app.ts",
+          text: {
+            value: "@src\\app.ts",
+            start: 6,
+            end: 17,
+          },
+        },
+      },
+    ]
+
+    const prompt = extractPromptFromParts(parts, { directory: "c:/repo" })
+    const file = prompt.find((part) => part.type === "file")
+
+    expect(file).toMatchObject({
+      type: "file",
+      path: "src\\app.ts",
+      selection: { startLine: 3, endLine: 5, startChar: 0, endChar: 0 },
+    })
+  })
+
+  test("keeps absolute file paths outside the workspace", () => {
+    const parts: Part[] = [
+      {
+        id: "text_1",
+        sessionID: "ses_1",
+        messageID: "msg_1",
+        type: "text",
+        text: "Check @D:\\other\\app.ts",
+      },
+      {
+        id: "file_1",
+        sessionID: "ses_1",
+        messageID: "msg_1",
+        type: "file",
+        mime: "text/plain",
+        url: "file:///D:/other/app.ts",
+        source: {
+          type: "file",
+          path: "D:\\other\\app.ts",
+          text: {
+            value: "@D:\\other\\app.ts",
+            start: 6,
+            end: 22,
+          },
+        },
+      },
+    ]
+
+    const prompt = extractPromptFromParts(parts, { directory: "C:/repo" })
+    const file = prompt.find((part) => part.type === "file")
+
+    expect(file).toMatchObject({
+      type: "file",
+      path: "D:\\other\\app.ts",
+    })
+  })
+})
diff --git a/packages/app/src/utils/prompt.ts b/packages/app/src/utils/prompt.ts
index 35aec0071aac..356d7305e48d 100644
--- a/packages/app/src/utils/prompt.ts
+++ b/packages/app/src/utils/prompt.ts
@@ -1,4 +1,5 @@
 import type { AgentPart as MessageAgentPart, FilePart, Part, TextPart } from "@opencode-ai/sdk/v2"
+import { getWorkspaceRelativePath } from "@opencode-ai/util/path"
 import type { AgentPart, FileAttachmentPart, ImageAttachmentPart, Prompt } from "@/context/prompt"
 
 type Inline =
@@ -59,20 +60,7 @@ export function extractPromptFromParts(parts: Part[], opts?: { directory?: strin
   const directory = opts?.directory
   const attachmentName = opts?.attachmentName ?? "attachment"
 
-  const toRelative = (path: string) => {
-    if (!directory) return path
-
-    const prefix = directory.endsWith("/") ? directory : directory + "/"
-    if (path.startsWith(prefix)) return path.slice(prefix.length)
-
-    if (path.startsWith(directory)) {
-      const next = path.slice(directory.length)
-      if (next.startsWith("/")) return next.slice(1)
-      return next
-    }
-
-    return path
-  }
+  const toRelative = (path: string) => (directory ? getWorkspaceRelativePath(path, directory) : path)
 
   const inline: Inline[] = []
   const images: ImageAttachmentPart[] = []
diff --git a/packages/app/src/utils/session-key.test.ts b/packages/app/src/utils/session-key.test.ts
new file mode 100644
index 000000000000..4a734c06db4b
--- /dev/null
+++ b/packages/app/src/utils/session-key.test.ts
@@ -0,0 +1,41 @@
+import { describe, expect, test } from "bun:test"
+import { base64Encode } from "@opencode-ai/util/encode"
+import {
+  normalizeSessionKey,
+  sessionDirKey,
+  sessionKey,
+  sessionParts,
+  sessionPathHelpers,
+  sessionScopeKey,
+  sessionScopeParts,
+} from "./session-key"
+
+describe("session-key", () => {
+  test("normalizes equivalent workspace aliases to one session key", () => {
+    expect(sessionDirKey(base64Encode("C:\\Repo\\"))).toBe(sessionDirKey(base64Encode("c:/repo")))
+    expect(sessionKey(base64Encode("C:\\Repo\\"), "one")).toBe(sessionKey(base64Encode("c:/repo"), "one"))
+    expect(sessionParts(sessionKey(base64Encode("C:\\Repo\\"), "one"))).toEqual({
+      dir: base64Encode("c:/repo"),
+      directory: "c:/repo",
+      id: "one",
+      key: `${base64Encode("c:/repo")}/one`,
+    })
+  })
+
+  test("builds path helpers from normalized session keys", () => {
+    const path = sessionPathHelpers(sessionKey(base64Encode("C:\\Repo\\"), "one"))
+    expect(path?.normalizeTab("file://src\\a.ts")).toBe("tab:file:src/a.ts")
+  })
+
+  test("normalizes equivalent inputs through one helper", () => {
+    expect(normalizeSessionKey(sessionKey(base64Encode("C:\\Repo\\"), "one"))).toBe(
+      normalizeSessionKey(sessionKey(base64Encode("c:/repo"), "one")),
+    )
+  })
+
+  test("builds cache scope keys with explicit workspace fallback", () => {
+    expect(sessionScopeKey("/repo")).toBe("/repo\n__workspace__")
+    expect(sessionScopeParts(sessionScopeKey("/repo", "one"))).toEqual({ dir: "/repo", id: "one" })
+    expect(sessionScopeParts(sessionScopeKey("/repo"))).toEqual({ dir: "/repo", id: undefined })
+  })
+})
diff --git a/packages/app/src/utils/session-key.ts b/packages/app/src/utils/session-key.ts
new file mode 100644
index 000000000000..2a9060616cab
--- /dev/null
+++ b/packages/app/src/utils/session-key.ts
@@ -0,0 +1,66 @@
+import { base64Encode } from "@opencode-ai/util/encode"
+import { createPathHelpers, workspacePathKey } from "@/context/file/path"
+import { decode64 } from "./base64"
+
+export const SESSION_SCOPE_WORKSPACE = "__workspace__"
+
+function decodeDir(input: string) {
+  const value = decode64(input)
+  if (!value) return
+  if (base64Encode(value) !== input) return
+  return value
+}
+
+const splitSessionKey = (input: string) => {
+  const split = input.indexOf("/")
+  if (split === -1) return { dir: input, id: undefined }
+  return {
+    dir: input.slice(0, split),
+    id: input.slice(split + 1),
+  }
+}
+
+export function sessionScopeKey(dir: string, id?: string) {
+  return `${dir}\n${id ?? SESSION_SCOPE_WORKSPACE}`
+}
+
+export function sessionScopeParts(input: string) {
+  const split = input.lastIndexOf("\n")
+  if (split < 0) return { dir: input, id: undefined }
+
+  const id = input.slice(split + 1)
+  return {
+    dir: input.slice(0, split),
+    id: id === SESSION_SCOPE_WORKSPACE ? undefined : id,
+  }
+}
+
+export function sessionDirKey(input: string) {
+  const dir = decodeDir(input)
+  if (!dir) return input
+  return base64Encode(workspacePathKey(dir))
+}
+
+export function sessionKey(dir: string, id?: string) {
+  const key = sessionDirKey(dir)
+  if (!id) return key
+  return `${key}/${id}`
+}
+
+export function sessionParts(input: string) {
+  const { dir, id } = splitSessionKey(input)
+  return {
+    dir: sessionDirKey(dir),
+    directory: decodeDir(dir),
+    id,
+    key: sessionKey(dir, id),
+  }
+}
+
+export const normalizeSessionKey = (input: string) => sessionParts(input).key
+
+export function sessionPathHelpers(input: string) {
+  const dir = sessionParts(input).directory
+  if (!dir) return
+  return createPathHelpers(() => dir)
+}
diff --git a/packages/app/src/utils/worktree.test.ts b/packages/app/src/utils/worktree.test.ts
index 8161e7ad8367..d0a5ac83eb26 100644
--- a/packages/app/src/utils/worktree.test.ts
+++ b/packages/app/src/utils/worktree.test.ts
@@ -11,6 +11,16 @@ describe("Worktree", () => {
     expect(Worktree.get(key)).toEqual({ status: "ready" })
   })
 
+  test("dedupes windows path aliases by workspace key", () => {
+    Worktree.pending("C:\\Repo\\Feature\\")
+
+    const waiting = Worktree.wait("c:/repo/feature")
+    Worktree.ready("C:/Repo/Feature")
+
+    expect(Worktree.get("c:/repo/feature")).toEqual({ status: "ready" })
+    return expect(waiting).resolves.toEqual({ status: "ready" })
+  })
+
   test("pending does not overwrite a terminal state", () => {
     const key = dir("pending")
     Worktree.failed(key, "boom")
diff --git a/packages/app/src/utils/worktree.ts b/packages/app/src/utils/worktree.ts
index 581afd5535e2..d3296e3b2b1f 100644
--- a/packages/app/src/utils/worktree.ts
+++ b/packages/app/src/utils/worktree.ts
@@ -1,4 +1,4 @@
-const normalize = (directory: string) => directory.replace(/[\\/]+$/, "")
+import { workspacePathKey, type WorkspaceKey, type WorkspacePath } from "@/context/file/path"
 
 type State =
   | {
@@ -12,9 +12,11 @@ type State =
       message: string
     }
 
-const state = new Map<string, State>()
+const key = (directory: WorkspacePath) => workspacePathKey(directory)
+
+const state = new Map<WorkspaceKey, State>()
 const waiters = new Map<
-  string,
+  WorkspaceKey,
   {
     promise: Promise<State>
     resolve: (state: State) => void
@@ -29,45 +31,43 @@ function deferred() {
   return { promise, resolve: box.resolve }
 }
 
+function settle(directory: WorkspacePath, next: Extract<State, { status: "ready" | "failed" }>) {
+  const id = key(directory)
+  state.set(id, next)
+
+  const waiter = waiters.get(id)
+  if (!waiter) return
+  waiters.delete(id)
+  waiter.resolve(next)
+}
+
 export const Worktree = {
-  get(directory: string) {
-    return state.get(normalize(directory))
+  get(directory: WorkspacePath) {
+    return state.get(key(directory))
   },
-  pending(directory: string) {
-    const key = normalize(directory)
-    const current = state.get(key)
+  pending(directory: WorkspacePath) {
+    const id = key(directory)
+    const current = state.get(id)
     if (current && current.status !== "pending") return
-    state.set(key, { status: "pending" })
+    state.set(id, { status: "pending" })
   },
-  ready(directory: string) {
-    const key = normalize(directory)
-    const next = { status: "ready" } as const
-    state.set(key, next)
-    const waiter = waiters.get(key)
-    if (!waiter) return
-    waiters.delete(key)
-    waiter.resolve(next)
+  ready(directory: WorkspacePath) {
+    settle(directory, { status: "ready" })
   },
-  failed(directory: string, message: string) {
-    const key = normalize(directory)
-    const next = { status: "failed", message } as const
-    state.set(key, next)
-    const waiter = waiters.get(key)
-    if (!waiter) return
-    waiters.delete(key)
-    waiter.resolve(next)
+  failed(directory: WorkspacePath, message: string) {
+    settle(directory, { status: "failed", message })
   },
-  wait(directory: string) {
-    const key = normalize(directory)
-    const current = state.get(key)
+  wait(directory: WorkspacePath) {
+    const id = key(directory)
+    const current = state.get(id)
     if (current && current.status !== "pending") return Promise.resolve(current)
 
-    const existing = waiters.get(key)
+    const existing = waiters.get(id)
     if (existing) return existing.promise
 
     const waiter = deferred()
 
-    waiters.set(key, waiter)
+    waiters.set(id, waiter)
     return waiter.promise
   },
 }
diff --git a/packages/desktop-electron/src/main/index.ts b/packages/desktop-electron/src/main/index.ts
index 484e4feb2077..45e2ba93d508 100644
--- a/packages/desktop-electron/src/main/index.ts
+++ b/packages/desktop-electron/src/main/index.ts
@@ -82,7 +82,6 @@ function setupApp() {
   })
 
   void app.whenReady().then(async () => {
-    // migrate()
     app.setAsDefaultProtocolClient("opencode")
     setDockIcon()
     setupAutoUpdater()
diff --git a/packages/desktop-electron/src/main/migrate.ts b/packages/desktop-electron/src/main/migrate.ts
deleted file mode 100644
index bad1349eeba1..000000000000
--- a/packages/desktop-electron/src/main/migrate.ts
+++ /dev/null
@@ -1,91 +0,0 @@
-import { app } from "electron"
-import log from "electron-log/main.js"
-import { existsSync, readdirSync, readFileSync } from "node:fs"
-import { homedir } from "node:os"
-import { join } from "node:path"
-import { CHANNEL } from "./constants"
-import { getStore, store } from "./store"
-
-const TAURI_MIGRATED_KEY = "tauriMigrated"
-
-// Resolve the directory where Tauri stored its .dat files for the given app identifier.
-// Mirrors Tauri's AppLocalData / AppData resolution per OS.
-function tauriDir(id: string) {
-  switch (process.platform) {
-    case "darwin":
-      return join(homedir(), "Library", "Application Support", id)
-    case "win32":
-      return join(process.env.APPDATA ?? join(homedir(), "AppData", "Roaming"), id)
-    default:
-      return join(process.env.XDG_DATA_HOME ?? join(homedir(), ".local", "share"), id)
-  }
-}
-
-// The Tauri app identifier changes between dev/beta/prod builds.
-const TAURI_APP_IDS: Record<string, string> = {
-  dev: "ai.opencode.desktop.dev",
-  beta: "ai.opencode.desktop.beta",
-  prod: "ai.opencode.desktop",
-}
-function tauriAppId() {
-  return app.isPackaged ? TAURI_APP_IDS[CHANNEL] : "ai.opencode.desktop.dev"
-}
-
-// Migrate a single Tauri .dat file into the corresponding electron-store.
-// `opencode.settings.dat` is special: it maps to the `opencode.settings` store
-// (the electron-store name without the `.dat` extension). All other .dat files
-// keep their full filename as the electron-store name so they match what the
-// renderer already passes via IPC (e.g. `"default.dat"`, `"opencode.global.dat"`).
-function migrateFile(datPath: string, filename: string) {
-  let data: Record<string, unknown>
-  try {
-    data = JSON.parse(readFileSync(datPath, "utf-8"))
-  } catch (err) {
-    log.warn("tauri migration: failed to parse", filename, err)
-    return
-  }
-
-  // opencode.settings.dat → the electron settings store ("opencode.settings").
-  // All other .dat files keep their full filename as the store name so they match
-  // what the renderer passes via IPC (e.g. "default.dat", "opencode.global.dat").
-  const storeName = filename === "opencode.settings.dat" ? "opencode.settings" : filename
-  const target = getStore(storeName)
-  const migrated: string[] = []
-  const skipped: string[] = []
-
-  for (const [key, value] of Object.entries(data)) {
-    // Don't overwrite values the user has already set in the Electron app.
-    if (target.has(key)) {
-      skipped.push(key)
-      continue
-    }
-    target.set(key, value)
-    migrated.push(key)
-  }
-
-  log.log("tauri migration: migrated", filename, "→", storeName, { migrated, skipped })
-}
-
-export function migrate() {
-  if (store.get(TAURI_MIGRATED_KEY)) {
-    log.log("tauri migration: already done, skipping")
-    return
-  }
-
-  const dir = tauriDir(tauriAppId())
-  log.log("tauri migration: starting", { dir })
-
-  if (!existsSync(dir)) {
-    log.log("tauri migration: no tauri data directory found, nothing to migrate")
-    store.set(TAURI_MIGRATED_KEY, true)
-    return
-  }
-
-  for (const filename of readdirSync(dir)) {
-    if (!filename.endsWith(".dat")) continue
-    migrateFile(join(dir, filename), filename)
-  }
-
-  log.log("tauri migration: complete")
-  store.set(TAURI_MIGRATED_KEY, true)
-}
diff --git a/packages/opencode/src/acp/agent.ts b/packages/opencode/src/acp/agent.ts
index 2a6bbbb1e444..abd5721018cd 100644
--- a/packages/opencode/src/acp/agent.ts
+++ b/packages/opencode/src/acp/agent.ts
@@ -29,7 +29,8 @@ import {
 } from "@agentclientprotocol/sdk"
 
 import { Log } from "../util/log"
-import { pathToFileURL } from "url"
+import { win32 } from "path"
+import { fileURLToPath, pathToFileURL } from "url"
 import { Filesystem } from "../util/filesystem"
 import { Hash } from "../util/hash"
 import { ACPSessionManager } from "./session"
@@ -98,7 +99,7 @@ export namespace ACP {
 
     const msg = lastAssistant.info
     if (!msg.providerID || !msg.modelID) return
-    const size = await getContextLimit(sdk, ProviderID.make(msg.providerID), ModelID.make(msg.modelID), directory)
+    const size = await getContextLimit(sdk, ProviderID.parse(msg.providerID), ModelID.parse(msg.modelID), directory)
 
     if (!size) {
       // Cannot calculate usage without known context size
@@ -1594,24 +1595,23 @@ export namespace ACP {
   ): { type: "file"; url: string; filename: string; mime: string } | { type: "text"; text: string } {
     try {
       if (uri.startsWith("file://")) {
-        const path = uri.slice(7)
-        const name = path.split("/").pop() || path
+        const url = new URL(uri)
+        const file = fileURLToPath(url)
         return {
           type: "file",
-          url: uri,
-          filename: name,
+          url: url.href,
+          filename: win32.basename(file),
           mime: "text/plain",
         }
       }
       if (uri.startsWith("zed://")) {
         const url = new URL(uri)
-        const path = url.searchParams.get("path")
-        if (path) {
-          const name = path.split("/").pop() || path
+        const file = url.searchParams.get("path")
+        if (file) {
           return {
             type: "file",
-            url: pathToFileURL(path).href,
-            filename: name,
+            url: pathToFileURL(file).href,
+            filename: win32.basename(file),
             mime: "text/plain",
           }
         }
diff --git a/packages/opencode/src/agent/agent.ts b/packages/opencode/src/agent/agent.ts
index 30d09861447e..84758961b69f 100644
--- a/packages/opencode/src/agent/agent.ts
+++ b/packages/opencode/src/agent/agent.ts
@@ -15,6 +15,7 @@ import PROMPT_EXPLORE from "./prompt/explore.txt"
 import PROMPT_SUMMARY from "./prompt/summary.txt"
 import PROMPT_TITLE from "./prompt/title.txt"
 import { Permission } from "@/permission"
+import { Path } from "@/path/path"
 import { mergeDeep, pipe, sortBy, values } from "remeda"
 import { Global } from "@/global"
 import path from "path"
@@ -105,7 +106,7 @@ export namespace Agent {
             edit: {
               "*": "deny",
               [path.join(".opencode", "plans", "*.md")]: "allow",
-              [path.relative(Instance.worktree, path.join(Global.Path.data, path.join("plans", "*.md")))]: "allow",
+              [String(Path.rel(Instance.worktree, path.join(Global.Path.data, "plans", "*.md")))]: "allow",
             },
           }),
           user,
@@ -232,13 +233,15 @@ export namespace Agent {
       item.permission = Permission.merge(item.permission, Permission.fromConfig(value.permission ?? {}))
     }
 
+    const trunc = Path.canonical(Truncate.GLOB)
+
     // Ensure Truncate.GLOB is allowed unless explicitly configured
     for (const name in result) {
       const agent = result[name]
       const explicit = agent.permission.some((r) => {
         if (r.permission !== "external_directory") return false
         if (r.action !== "deny") return false
-        return r.pattern === Truncate.GLOB
+        return Path.canonical(r.pattern) === trunc
       })
       if (explicit) continue
 
diff --git a/packages/opencode/src/cli/cmd/dir.ts b/packages/opencode/src/cli/cmd/dir.ts
new file mode 100644
index 000000000000..ec74a7a780ec
--- /dev/null
+++ b/packages/opencode/src/cli/cmd/dir.ts
@@ -0,0 +1,17 @@
+import { Path } from "@/path/path"
+
+type Opts = {
+  cwd?: string
+  remote?: boolean
+}
+
+export function cwd(input?: string) {
+  return input ?? process.env.PWD ?? process.cwd()
+}
+
+export function dir(input: string, opts: Opts = {}) {
+  if (!opts.remote) return Path.pretty(input, { cwd: cwd(opts.cwd) })
+  const pf = Path.guess(input)
+  if (!pf) return input
+  return Path.pretty(input, { platform: pf })
+}
diff --git a/packages/opencode/src/cli/cmd/export.ts b/packages/opencode/src/cli/cmd/export.ts
index 4088b4818d2b..5d7ffb08eae1 100644
--- a/packages/opencode/src/cli/cmd/export.ts
+++ b/packages/opencode/src/cli/cmd/export.ts
@@ -18,7 +18,15 @@ export const ExportCommand = cmd({
   },
   handler: async (args) => {
     await bootstrap(process.cwd(), async () => {
-      let sessionID = args.sessionID ? SessionID.make(args.sessionID) : undefined
+      let sessionID = (() => {
+        if (!args.sessionID) return
+        try {
+          return SessionID.parse(args.sessionID)
+        } catch (err) {
+          UI.error(err instanceof Error ? err.message : `Invalid session id: ${args.sessionID}`)
+          process.exit(1)
+        }
+      })()
       process.stderr.write(`Exporting session: ${sessionID ?? "latest"}\n`)
 
       if (!sessionID) {
diff --git a/packages/opencode/src/cli/cmd/github.ts b/packages/opencode/src/cli/cmd/github.ts
index edd9d7561094..dd68d1cd6096 100644
--- a/packages/opencode/src/cli/cmd/github.ts
+++ b/packages/opencode/src/cli/cmd/github.ts
@@ -955,15 +955,6 @@ export const GithubRunCommand = cmd({
                 mime: f.mime,
                 url: `data:${f.mime};base64,${f.content}`,
                 filename: f.filename,
-                source: {
-                  type: "file" as const,
-                  text: {
-                    value: f.replacement,
-                    start: f.start,
-                    end: f.end,
-                  },
-                  path: f.filename,
-                },
               },
             ]),
           ],
diff --git a/packages/opencode/src/cli/cmd/models.ts b/packages/opencode/src/cli/cmd/models.ts
index 3e3672926d08..464bd3a13130 100644
--- a/packages/opencode/src/cli/cmd/models.ts
+++ b/packages/opencode/src/cli/cmd/models.ts
@@ -51,13 +51,21 @@ export const ModelsCommand = cmd({
         }
 
         if (args.provider) {
-          const provider = providers[ProviderID.make(args.provider)]
+          let providerID: ProviderID
+          try {
+            providerID = ProviderID.parse(args.provider)
+          } catch (err) {
+            UI.error(err instanceof Error ? err.message : `Invalid provider id: ${args.provider}`)
+            return
+          }
+
+          const provider = providers[providerID]
           if (!provider) {
             UI.error(`Provider not found: ${args.provider}`)
             return
           }
 
-          printModels(ProviderID.make(args.provider), args.verbose)
+          printModels(providerID, args.verbose)
           return
         }
 
@@ -70,7 +78,7 @@ export const ModelsCommand = cmd({
         })
 
         for (const providerID of providerIDs) {
-          printModels(ProviderID.make(providerID), args.verbose)
+          printModels(ProviderID.parse(providerID), args.verbose)
         }
       },
     })
diff --git a/packages/opencode/src/cli/cmd/providers.ts b/packages/opencode/src/cli/cmd/providers.ts
index 581809e90eb4..eb7fafcc2c61 100644
--- a/packages/opencode/src/cli/cmd/providers.ts
+++ b/packages/opencode/src/cli/cmd/providers.ts
@@ -5,7 +5,6 @@ import { UI } from "../ui"
 import { ModelsDev } from "../../provider/models"
 import { map, pipe, sortBy, values } from "remeda"
 import path from "path"
-import os from "os"
 import { Config } from "../../config/config"
 import { Global } from "../../global"
 import { Plugin } from "../../plugin"
@@ -13,6 +12,7 @@ import { Instance } from "../../project/instance"
 import type { Hooks } from "@opencode-ai/plugin"
 import { Process } from "../../util/process"
 import { text } from "node:stream/consumers"
+import { Path } from "../../path/path"
 
 type PluginAuth = NonNullable<Hooks["auth"]>
 
@@ -212,8 +212,7 @@ export const ProvidersListCommand = cmd({
   async handler(_args) {
     UI.empty()
     const authPath = path.join(Global.Path.data, "auth.json")
-    const homedir = os.homedir()
-    const displayPath = authPath.startsWith(homedir) ? authPath.replace(homedir, "~") : authPath
+    const displayPath = Path.display(authPath)
     prompts.intro(`Credentials ${UI.Style.TEXT_DIM}${displayPath}`)
     const results = Object.entries(await Auth.all())
     const database = await ModelsDev.get()
diff --git a/packages/opencode/src/cli/cmd/run.ts b/packages/opencode/src/cli/cmd/run.ts
index 0aeb864e8679..1da58b6fb32f 100644
--- a/packages/opencode/src/cli/cmd/run.ts
+++ b/packages/opencode/src/cli/cmd/run.ts
@@ -1,6 +1,5 @@
 import type { Argv } from "yargs"
 import path from "path"
-import { pathToFileURL } from "url"
 import { UI } from "../ui"
 import { cmd } from "./cmd"
 import { Flag } from "../../flag/flag"
@@ -27,6 +26,8 @@ import { SkillTool } from "../../tool/skill"
 import { BashTool } from "../../tool/bash"
 import { TodoWriteTool } from "../../tool/todo"
 import { Locale } from "../../util/locale"
+import { Path } from "@/path/path"
+import * as Dir from "./dir"
 
 type ToolProps<T extends Tool.Info> = {
   input: Tool.InferParameters<T>
@@ -214,8 +215,7 @@ function todo(info: ToolProps<typeof TodoWriteTool>) {
 
 function normalizePath(input?: string) {
   if (!input) return ""
-  if (path.isAbsolute(input)) return path.relative(process.cwd(), input) || "."
-  return input
+  return Path.display(input, { cwd: process.cwd(), home: false, relative: true })
 }
 
 export const RunCommand = cmd({
@@ -304,18 +304,20 @@ export const RunCommand = cmd({
       })
   },
   handler: async (args) => {
+    const root = Dir.cwd()
     let message = [...args.message, ...(args["--"] || [])]
       .map((arg) => (arg.includes(" ") ? `"${arg.replace(/"/g, '\\"')}"` : arg))
       .join(" ")
 
     const directory = (() => {
       if (!args.dir) return undefined
-      if (args.attach) return args.dir
+      const next = Dir.dir(args.dir, { cwd: root, remote: !!args.attach })
+      if (args.attach) return next
       try {
-        process.chdir(args.dir)
-        return process.cwd()
+        process.chdir(next)
+        return next
       } catch {
-        UI.error("Failed to change directory to " + args.dir)
+        UI.error("Failed to change directory to " + next)
         process.exit(1)
       }
     })()
@@ -325,7 +327,7 @@ export const RunCommand = cmd({
       const list = Array.isArray(args.file) ? args.file : [args.file]
 
       for (const filePath of list) {
-        const resolvedPath = path.resolve(process.cwd(), filePath)
+        const resolvedPath = Path.pretty(filePath, { cwd: args.attach ? root : directory ?? process.cwd() })
         if (!(await Filesystem.exists(resolvedPath))) {
           UI.error(`File not found: ${filePath}`)
           process.exit(1)
@@ -335,7 +337,7 @@ export const RunCommand = cmd({
 
         files.push({
           type: "file",
-          url: pathToFileURL(resolvedPath).href,
+          url: String(Path.uri(resolvedPath)),
           filename: path.basename(resolvedPath),
           mime,
         })
@@ -664,7 +666,7 @@ export const RunCommand = cmd({
       return await execute(sdk)
     }
 
-    await bootstrap(process.cwd(), async () => {
+    await bootstrap(directory ?? process.cwd(), async () => {
       const fetchFn = (async (input: RequestInfo | URL, init?: RequestInit) => {
         const request = new Request(input, init)
         return Server.Default().fetch(request)
diff --git a/packages/opencode/src/cli/cmd/session.ts b/packages/opencode/src/cli/cmd/session.ts
index 8acd7480c941..324c799dbe9e 100644
--- a/packages/opencode/src/cli/cmd/session.ts
+++ b/packages/opencode/src/cli/cmd/session.ts
@@ -58,7 +58,13 @@ export const SessionDeleteCommand = cmd({
   },
   handler: async (args) => {
     await bootstrap(process.cwd(), async () => {
-      const sessionID = SessionID.make(args.sessionID)
+      let sessionID: SessionID
+      try {
+        sessionID = SessionID.parse(args.sessionID)
+      } catch (err) {
+        UI.error(err instanceof Error ? err.message : `Invalid session id: ${args.sessionID}`)
+        process.exit(1)
+      }
       try {
         await Session.get(sessionID)
       } catch {
diff --git a/packages/opencode/src/cli/cmd/tui/attach.ts b/packages/opencode/src/cli/cmd/tui/attach.ts
index e892f9922d1b..109ed07c8b0a 100644
--- a/packages/opencode/src/cli/cmd/tui/attach.ts
+++ b/packages/opencode/src/cli/cmd/tui/attach.ts
@@ -5,6 +5,16 @@ import { win32DisableProcessedInput, win32InstallCtrlCGuard } from "./win32"
 import { TuiConfig } from "@/config/tui"
 import { Instance } from "@/project/instance"
 import { existsSync } from "fs"
+import * as Dir from "../dir"
+
+function local(url: string) {
+  try {
+    const host = new URL(url).hostname
+    return host === "localhost" || host === "127.0.0.1" || host === "::1"
+  } catch {
+    return false
+  }
+}
 
 export const AttachCommand = cmd({
   command: "attach <url>",
@@ -43,6 +53,8 @@ export const AttachCommand = cmd({
     const unguard = win32InstallCtrlCGuard()
     try {
       win32DisableProcessedInput()
+      const root = Dir.cwd()
+      const nearby = local(args.url)
 
       if (args.fork && !args.continue && !args.session) {
         UI.error("--fork requires --continue or --session")
@@ -52,12 +64,14 @@ export const AttachCommand = cmd({
 
       const directory = (() => {
         if (!args.dir) return undefined
+        const next = Dir.dir(args.dir, { cwd: root, remote: !nearby })
+        if (!nearby) return next
         try {
-          process.chdir(args.dir)
-          return process.cwd()
+          process.chdir(next)
+          return next
         } catch {
           // If the directory doesn't exist locally (remote attach), pass it through.
-          return args.dir
+          return Dir.dir(args.dir, { cwd: root, remote: true })
         }
       })()
       const headers = (() => {
@@ -67,7 +81,7 @@ export const AttachCommand = cmd({
         return { Authorization: auth }
       })()
       const config = await Instance.provide({
-        directory: directory && existsSync(directory) ? directory : process.cwd(),
+        directory: nearby && directory && existsSync(directory) ? directory : root,
         fn: () => TuiConfig.get(),
       })
       await tui({
diff --git a/packages/opencode/src/cli/cmd/tui/component/dialog-status.tsx b/packages/opencode/src/cli/cmd/tui/component/dialog-status.tsx
index 3b6b5ef21827..39321739b4fb 100644
--- a/packages/opencode/src/cli/cmd/tui/component/dialog-status.tsx
+++ b/packages/opencode/src/cli/cmd/tui/component/dialog-status.tsx
@@ -1,9 +1,10 @@
 import { TextAttributes } from "@opentui/core"
-import { fileURLToPath } from "bun"
 import { useTheme } from "../context/theme"
 import { useDialog } from "@tui/ui/dialog"
 import { useSync } from "@tui/context/sync"
 import { For, Match, Switch, Show, createMemo } from "solid-js"
+import { Path } from "@/path/path"
+import { formatPath, plugin } from "../util/path"
 
 export type DialogStatusProps = {}
 
@@ -11,31 +12,13 @@ export function DialogStatus() {
   const sync = useSync()
   const { theme } = useTheme()
   const dialog = useDialog()
+  const platform = createMemo(() => Path.platform(sync.data.path.os))
 
   const enabledFormatters = createMemo(() => sync.data.formatter.filter((f) => f.enabled))
 
   const plugins = createMemo(() => {
     const list = sync.data.config.plugin ?? []
-    const result = list.map((value) => {
-      if (value.startsWith("file://")) {
-        const path = fileURLToPath(value)
-        const parts = path.split("/")
-        const filename = parts.pop() || path
-        if (!filename.includes(".")) return { name: filename }
-        const basename = filename.split(".")[0]
-        if (basename === "index") {
-          const dirname = parts.pop()
-          const name = dirname || basename
-          return { name }
-        }
-        return { name: basename }
-      }
-      const index = value.lastIndexOf("@")
-      if (index <= 0) return { name: value, version: "latest" }
-      const name = value.substring(0, index)
-      const version = value.substring(index + 1)
-      return { name, version }
-    })
+    const result = list.map((value) => plugin(value))
     return result.toSorted((a, b) => a.name.localeCompare(b.name))
   })
 
@@ -110,7 +93,10 @@ export function DialogStatus() {
                   •
                 </text>
                 <text fg={theme.text} wrapMode="word">
-                  <b>{item.id}</b> <span style={{ fg: theme.textMuted }}>{item.root}</span>
+                  <b>{item.id}</b>{" "}
+                  <span style={{ fg: theme.textMuted }}>
+                    {formatPath(item.root, { home: sync.data.path.home, platform: platform() })}
+                  </span>
                 </text>
               </box>
             )}
diff --git a/packages/opencode/src/cli/cmd/tui/component/prompt/autocomplete.tsx b/packages/opencode/src/cli/cmd/tui/component/prompt/autocomplete.tsx
index 3240afab326a..cbddb468b727 100644
--- a/packages/opencode/src/cli/cmd/tui/component/prompt/autocomplete.tsx
+++ b/packages/opencode/src/cli/cmd/tui/component/prompt/autocomplete.tsx
@@ -1,5 +1,4 @@
 import type { BoxRenderable, TextareaRenderable, KeyEvent, ScrollBoxRenderable } from "@opentui/core"
-import { pathToFileURL } from "bun"
 import fuzzysort from "fuzzysort"
 import { firstBy } from "remeda"
 import { createMemo, createResource, createEffect, onMount, onCleanup, Index, Show, createSignal } from "solid-js"
@@ -11,8 +10,10 @@ import { SplitBorder } from "@tui/component/border"
 import { useCommandDialog } from "@tui/component/dialog-command"
 import { useTerminalDimensions } from "@opentui/solid"
 import { Locale } from "@/util/locale"
+import { Path } from "@/path/path"
 import type { PromptInfo } from "./history"
 import { useFrecency } from "./frecency"
+import { serverPathOpts } from "../../util/path"
 
 function removeLineRange(input: string) {
   const hashIndex = input.lastIndexOf("#")
@@ -238,21 +239,31 @@ export function Autocomplete(props: {
           const aScore = frecency.getFrecency(a)
           const bScore = frecency.getFrecency(b)
           if (aScore !== bScore) return bScore - aScore
-          const aDepth = a.split("/").length
-          const bDepth = b.split("/").length
+          const aDepth = Path.repoDepth(a)
+          const bDepth = Path.repoDepth(b)
           if (aDepth !== bDepth) return aDepth - bDepth
           return a.localeCompare(b)
         })
 
         const width = props.anchor().width - 4
+        const platform = Path.platform(sync.data.path.os)
+        const cwd = sync.data.path.directory
         options.push(
-          ...sortedFiles.map((item): AutocompleteOption => {
-            const baseDir = (sync.data.path.directory || process.cwd()).replace(/\/+$/, "")
-            const fullPath = `${baseDir}/${item}`
-            const urlObj = pathToFileURL(fullPath)
-            let filename = item
-            if (lineRange && !item.endsWith("/")) {
-              filename = `${item}#${lineRange.startLine}${lineRange.endLine ? `-${lineRange.endLine}` : ""}`
+          ...sortedFiles.flatMap((item) => {
+            if (!cwd && !Path.isAbsolute(item, { platform })) return []
+
+            const urlObj = new URL(
+              String(
+                Path.uri(item, {
+                  ...serverPathOpts(sync.data.path),
+                }),
+              ),
+            )
+            const key = String(Path.repo(item))
+            const isDir = Path.repoIsDir(key)
+            let filename = key
+            if (lineRange && !isDir) {
+              filename = `${key}#${lineRange.startLine}${lineRange.endLine ? `-${lineRange.endLine}` : ""}`
               urlObj.searchParams.set("start", String(lineRange.startLine))
               if (lineRange.endLine !== undefined) {
                 urlObj.searchParams.set("end", String(lineRange.endLine))
@@ -260,30 +271,31 @@ export function Autocomplete(props: {
             }
             const url = urlObj.href
 
-            const isDir = item.endsWith("/")
-            return {
-              display: Locale.truncateMiddle(filename, width),
-              value: filename,
-              isDirectory: isDir,
-              path: item,
-              onSelect: () => {
-                insertPart(filename, {
-                  type: "file",
-                  mime: "text/plain",
-                  filename,
-                  url,
-                  source: {
+            return [
+              {
+                display: Locale.truncateMiddle(filename, width),
+                value: filename,
+                isDirectory: isDir,
+                path: key,
+                onSelect: () => {
+                  insertPart(filename, {
                     type: "file",
-                    text: {
-                      start: 0,
-                      end: 0,
-                      value: "",
+                    mime: "text/plain",
+                    filename,
+                    url,
+                    source: {
+                      type: "file",
+                      text: {
+                        start: 0,
+                        end: 0,
+                        value: "",
+                      },
+                      path: key,
                     },
-                    path: item,
-                  },
-                })
-              },
-            }
+                  })
+                },
+              } satisfies AutocompleteOption,
+            ]
           }),
         )
       }
@@ -461,8 +473,8 @@ export function Autocomplete(props: {
     const input = props.input()
     const currentCursorOffset = input.cursorOffset
 
-    const displayText = selected.display.trimEnd()
-    const path = displayText.startsWith("@") ? displayText.slice(1) : displayText
+    const value = (selected.value ?? selected.display).trimEnd()
+    const path = value.startsWith("@") ? value.slice(1) : value
 
     input.cursorOffset = store.index
     const startCursor = input.logicalCursor
diff --git a/packages/opencode/src/cli/cmd/tui/component/prompt/frecency.tsx b/packages/opencode/src/cli/cmd/tui/component/prompt/frecency.tsx
index 3ea8826ef8bd..d9319c27e365 100644
--- a/packages/opencode/src/cli/cmd/tui/component/prompt/frecency.tsx
+++ b/packages/opencode/src/cli/cmd/tui/component/prompt/frecency.tsx
@@ -5,6 +5,15 @@ import { onMount } from "solid-js"
 import { createStore } from "solid-js/store"
 import { createSimpleContext } from "../../context/helper"
 import { appendFile, writeFile } from "fs/promises"
+import { useSync } from "../../context/sync"
+import { serverPathKey } from "../../util/path"
+
+type Entry = {
+  key?: string
+  path: string
+  frequency: number
+  lastOpen: number
+}
 
 function calculateFrecency(entry?: { frequency: number; lastOpen: number }): number {
   if (!entry) return 0
@@ -18,6 +27,7 @@ const MAX_FRECENCY_ENTRIES = 1000
 export const { use: useFrecency, provider: FrecencyProvider } = createSimpleContext({
   name: "Frecency",
   init: () => {
+    const sync = useSync()
     const frecencyPath = path.join(Global.Path.state, "frecency.jsonl")
     onMount(async () => {
       const text = await Filesystem.readText(frecencyPath).catch(() => "")
@@ -26,19 +36,19 @@ export const { use: useFrecency, provider: FrecencyProvider } = createSimpleCont
         .filter(Boolean)
         .map((line) => {
           try {
-            return JSON.parse(line) as { path: string; frequency: number; lastOpen: number }
+            return JSON.parse(line) as Entry
           } catch {
             return null
           }
         })
-        .filter((line): line is { path: string; frequency: number; lastOpen: number } => line !== null)
+        .filter((line): line is Entry => line !== null)
 
       const latest = lines.reduce(
         (acc, entry) => {
-          acc[entry.path] = entry
+          acc[entry.key ?? entry.path] = entry
           return acc
         },
-        {} as Record<string, { path: string; frequency: number; lastOpen: number }>,
+        {} as Record<string, Entry>,
       )
 
       const sorted = Object.values(latest)
@@ -48,7 +58,7 @@ export const { use: useFrecency, provider: FrecencyProvider } = createSimpleCont
       setStore(
         "data",
         Object.fromEntries(
-          sorted.map((entry) => [entry.path, { frequency: entry.frequency, lastOpen: entry.lastOpen }]),
+          sorted.map((entry) => [entry.key ?? entry.path, { frequency: entry.frequency, lastOpen: entry.lastOpen }]),
         ),
       )
 
@@ -63,26 +73,26 @@ export const { use: useFrecency, provider: FrecencyProvider } = createSimpleCont
     })
 
     function updateFrecency(filePath: string) {
-      const absolutePath = path.resolve(process.cwd(), filePath)
+      const key = serverPathKey(filePath, sync.data.path)
       const newEntry = {
-        frequency: (store.data[absolutePath]?.frequency || 0) + 1,
+        frequency: (store.data[key]?.frequency || 0) + 1,
         lastOpen: Date.now(),
       }
-      setStore("data", absolutePath, newEntry)
-      appendFile(frecencyPath, JSON.stringify({ path: absolutePath, ...newEntry }) + "\n").catch(() => {})
+      setStore("data", key, newEntry)
+      appendFile(frecencyPath, JSON.stringify({ key, path: filePath, ...newEntry }) + "\n").catch(() => {})
 
       if (Object.keys(store.data).length > MAX_FRECENCY_ENTRIES) {
         const sorted = Object.entries(store.data)
           .sort(([, a], [, b]) => b.lastOpen - a.lastOpen)
           .slice(0, MAX_FRECENCY_ENTRIES)
         setStore("data", Object.fromEntries(sorted))
-        const content = sorted.map(([path, entry]) => JSON.stringify({ path, ...entry })).join("\n") + "\n"
+        const content = sorted.map(([key, entry]) => JSON.stringify({ key, path: key, ...entry })).join("\n") + "\n"
         writeFile(frecencyPath, content).catch(() => {})
       }
     }
 
     return {
-      getFrecency: (filePath: string) => calculateFrecency(store.data[path.resolve(process.cwd(), filePath)]),
+      getFrecency: (filePath: string) => calculateFrecency(store.data[serverPathKey(filePath, sync.data.path)]),
       updateFrecency,
       data: () => store.data,
     }
diff --git a/packages/opencode/src/cli/cmd/tui/context/directory.ts b/packages/opencode/src/cli/cmd/tui/context/directory.ts
index 17e5c180a19a..71939697d053 100644
--- a/packages/opencode/src/cli/cmd/tui/context/directory.ts
+++ b/packages/opencode/src/cli/cmd/tui/context/directory.ts
@@ -1,13 +1,12 @@
 import { createMemo } from "solid-js"
 import { useSync } from "./sync"
-import { Global } from "@/global"
+import { formatServerPath } from "../util/path"
 
 export function useDirectory() {
   const sync = useSync()
   return createMemo(() => {
-    const directory = sync.data.path.directory || process.cwd()
-    const result = directory.replace(Global.Path.home, "~")
-    if (sync.data.vcs?.branch) return result + ":" + sync.data.vcs.branch
+    const result = formatServerPath(sync.data.path.directory, sync.data.path)
+    if (sync.data.vcs?.branch) return result ? result + ":" + sync.data.vcs.branch : sync.data.vcs.branch
     return result
   })
 }
diff --git a/packages/opencode/src/cli/cmd/tui/context/sync.tsx b/packages/opencode/src/cli/cmd/tui/context/sync.tsx
index 3b296a927aa4..401d452e6439 100644
--- a/packages/opencode/src/cli/cmd/tui/context/sync.tsx
+++ b/packages/opencode/src/cli/cmd/tui/context/sync.tsx
@@ -16,6 +16,7 @@ import type {
   SessionStatus,
   ProviderListResponse,
   ProviderAuthMethod,
+  Path,
   VcsInfo,
 } from "@opencode-ai/sdk/v2"
 import { createStore, produce, reconcile } from "solid-js/store"
@@ -27,7 +28,6 @@ import { useExit } from "./exit"
 import { useArgs } from "./args"
 import { batch, onMount } from "solid-js"
 import { Log } from "@/util/log"
-import type { Path } from "@opencode-ai/sdk"
 import type { Workspace } from "@opencode-ai/sdk/v2"
 
 export const { use: useSync, provider: SyncProvider } = createSimpleContext({
@@ -101,7 +101,14 @@ export const { use: useSync, provider: SyncProvider } = createSimpleContext({
       mcp_resource: {},
       formatter: [],
       vcs: undefined,
-      path: { state: "", config: "", worktree: "", directory: "" },
+      path: {
+        os: process.platform === "win32" ? "windows" : process.platform === "darwin" ? "macos" : "linux",
+        home: "",
+        state: "",
+        config: "",
+        worktree: "",
+        directory: "",
+      },
       workspaceList: [],
     })
 
diff --git a/packages/opencode/src/cli/cmd/tui/routes/session/index.tsx b/packages/opencode/src/cli/cmd/tui/routes/session/index.tsx
index 0d9ddc746c2a..67280a9f49e9 100644
--- a/packages/opencode/src/cli/cmd/tui/routes/session/index.tsx
+++ b/packages/opencode/src/cli/cmd/tui/routes/session/index.tsx
@@ -16,6 +16,7 @@ import { Dynamic } from "solid-js/web"
 import path from "path"
 import { useRoute, useRouteData } from "@tui/context/route"
 import { useSync } from "@tui/context/sync"
+import { Path } from "@/path/path"
 import { SplitBorder } from "@tui/component/border"
 import { Spinner } from "@tui/component/spinner"
 import { selectedForeground, useTheme } from "@tui/context/theme"
@@ -57,6 +58,7 @@ import { useDialog } from "../../ui/dialog"
 import { TodoItem } from "../../component/todo-item"
 import { DialogMessage } from "./dialog-message"
 import type { PromptInfo } from "../../component/prompt/history"
+import { Filesystem } from "@/util/filesystem"
 import { DialogConfirm } from "@tui/ui/dialog-confirm"
 import { DialogTimeline } from "./dialog-timeline"
 import { DialogForkFromTimeline } from "./dialog-fork-from-timeline"
@@ -73,14 +75,13 @@ import stripAnsi from "strip-ansi"
 import { Footer } from "./footer.tsx"
 import { usePromptRef } from "../../context/prompt"
 import { useExit } from "../../context/exit"
-import { Filesystem } from "@/util/filesystem"
-import { Global } from "@/global"
 import { PermissionPrompt } from "./permission"
 import { QuestionPrompt } from "./question"
 import { DialogExportOptions } from "../../ui/dialog-export-options"
 import { formatTranscript } from "../../util/transcript"
 import { UI } from "@/cli/ui.ts"
 import { useTuiConfig } from "../../context/tui-config"
+import { formatPath, formatServerPath } from "../../util/path"
 
 addDefaultParsers(parsers.parsers)
 
@@ -1116,7 +1117,7 @@ export function Session() {
                                   <For each={revert()!.diffFiles}>
                                     {(file) => (
                                       <text fg={theme.text}>
-                                        {file.filename}
+                                        {normalizePath(file.filename)}
                                         <Show when={file.additions > 0}>
                                           <span style={{ fg: theme.diffAdded }}> +{file.additions}</span>
                                         </Show>
@@ -1782,6 +1783,7 @@ function Bash(props: ToolProps<typeof BashTool>) {
   const [expanded, setExpanded] = createSignal(false)
   const lines = createMemo(() => output().split("\n"))
   const overflow = createMemo(() => lines().length > 10)
+  const platform = createMemo(() => Path.platform(sync.data.path.os))
   const limited = createMemo(() => {
     if (expanded() || !overflow()) return output()
     return [...lines().slice(0, 10), "…"].join("\n")
@@ -1794,14 +1796,16 @@ function Bash(props: ToolProps<typeof BashTool>) {
     const base = sync.data.path.directory
     if (!base) return undefined
 
-    const absolute = path.resolve(base, workdir)
+    const absolute = Path.pretty(workdir, {
+      cwd: base,
+      platform: platform(),
+    })
     if (absolute === base) return undefined
 
-    const home = Global.Path.home
-    if (!home) return absolute
-
-    const match = absolute === home || absolute.startsWith(home + path.sep)
-    return match ? absolute.replace(home, "~") : absolute
+    return formatPath(absolute, {
+      home: sync.data.path.home,
+      platform: platform(),
+    })
   })
 
   const title = createMemo(() => {
@@ -2130,10 +2134,11 @@ function ApplyPatch(props: ToolProps<typeof ApplyPatchTool>) {
   }
 
   function title(file: { type: string; relativePath: string; filePath: string; deletions: number }) {
-    if (file.type === "delete") return "# Deleted " + file.relativePath
-    if (file.type === "add") return "# Created " + file.relativePath
-    if (file.type === "move") return "# Moved " + normalizePath(file.filePath) + " → " + file.relativePath
-    return "← Patched " + file.relativePath
+    if (file.type === "delete") return "# Deleted " + normalizePath(file.relativePath)
+    if (file.type === "add") return "# Created " + normalizePath(file.relativePath)
+    if (file.type === "move")
+      return "# Moved " + normalizePath(file.filePath) + " → " + normalizePath(file.relativePath)
+    return "← Patched " + normalizePath(file.relativePath)
   }
 
   return (
@@ -2232,7 +2237,7 @@ function Skill(props: ToolProps<typeof SkillTool>) {
 function Diagnostics(props: { diagnostics?: Record<string, Record<string, any>[]>; filePath: string }) {
   const { theme } = useTheme()
   const errors = createMemo(() => {
-    const normalized = Filesystem.normalizePath(props.filePath)
+    const normalized = Path.truecaseSync(props.filePath)
     const arr = props.diagnostics?.[normalized] ?? []
     return arr.filter((x) => x.severity === 1).slice(0, 3)
   })
@@ -2253,17 +2258,7 @@ function Diagnostics(props: { diagnostics?: Record<string, Record<string, any>[]
 }
 
 function normalizePath(input?: string) {
-  if (!input) return ""
-
-  const cwd = process.cwd()
-  const absolute = path.isAbsolute(input) ? input : path.resolve(cwd, input)
-  const relative = path.relative(cwd, absolute)
-
-  if (!relative) return "."
-  if (!relative.startsWith("..")) return relative
-
-  // outside cwd - use absolute
-  return absolute
+  return formatServerPath(input, use().sync.data.path, { relative: true })
 }
 
 function input(input: Record<string, any>, omit?: string[]): string {
diff --git a/packages/opencode/src/cli/cmd/tui/routes/session/permission.tsx b/packages/opencode/src/cli/cmd/tui/routes/session/permission.tsx
index a50cd96fc843..d6acdb730ddc 100644
--- a/packages/opencode/src/cli/cmd/tui/routes/session/permission.tsx
+++ b/packages/opencode/src/cli/cmd/tui/routes/session/permission.tsx
@@ -13,28 +13,15 @@ import path from "path"
 import { LANGUAGE_EXTENSIONS } from "@/lsp/language"
 import { Keybind } from "@/util/keybind"
 import { Locale } from "@/util/locale"
-import { Global } from "@/global"
 import { useDialog } from "../../ui/dialog"
 import { useTuiConfig } from "../../context/tui-config"
+import { formatServerPath } from "../../util/path"
 
 type PermissionStage = "permission" | "always" | "reject"
 
 function normalizePath(input?: string) {
-  if (!input) return ""
-
-  const cwd = process.cwd()
-  const home = Global.Path.home
-  const absolute = path.isAbsolute(input) ? input : path.resolve(cwd, input)
-  const relative = path.relative(cwd, absolute)
-
-  if (!relative) return "."
-  if (!relative.startsWith("..")) return relative
-
-  // outside cwd - use ~ or absolute
-  if (home && (absolute === home || absolute.startsWith(home + path.sep))) {
-    return absolute.replace(home, "~")
-  }
-  return absolute
+  const sync = useSync()
+  return formatServerPath(input, sync.data.path, { relative: true })
 }
 
 function filetype(input?: string) {
@@ -167,7 +154,7 @@ export function PermissionPrompt(props: { request: PermissionRequest }) {
                       {(pattern) => (
                         <text fg={theme.text}>
                           {"- "}
-                          {pattern}
+                          {normalizePath(pattern)}
                         </text>
                       )}
                     </For>
@@ -363,8 +350,9 @@ export function PermissionPrompt(props: { request: PermissionRequest }) {
               const parent = typeof meta["parentDir"] === "string" ? meta["parentDir"] : undefined
               const filepath = typeof meta["filepath"] === "string" ? meta["filepath"] : undefined
               const pattern = props.request.patterns?.[0]
+              const mod = sync.data.path.os === "windows" ? path.win32 : path.posix
               const derived =
-                typeof pattern === "string" ? (pattern.includes("*") ? path.dirname(pattern) : pattern) : undefined
+                typeof pattern === "string" ? (pattern.includes("*") ? mod.dirname(pattern) : pattern) : undefined
 
               const raw = parent ?? filepath ?? derived
               const dir = normalizePath(raw)
@@ -378,7 +366,7 @@ export function PermissionPrompt(props: { request: PermissionRequest }) {
                     <box paddingLeft={1} gap={1}>
                       <text fg={theme.textMuted}>Patterns</text>
                       <box>
-                        <For each={patterns}>{(p) => <text fg={theme.text}>{"- " + p}</text>}</For>
+                        <For each={patterns}>{(p) => <text fg={theme.text}>{"- " + normalizePath(p)}</text>}</For>
                       </box>
                     </box>
                   </Show>
diff --git a/packages/opencode/src/cli/cmd/tui/routes/session/sidebar.tsx b/packages/opencode/src/cli/cmd/tui/routes/session/sidebar.tsx
index 42ac5fbe080a..e6f1aa7bf3db 100644
--- a/packages/opencode/src/cli/cmd/tui/routes/session/sidebar.tsx
+++ b/packages/opencode/src/cli/cmd/tui/routes/session/sidebar.tsx
@@ -2,15 +2,12 @@ import { useSync } from "@tui/context/sync"
 import { createMemo, For, Show, Switch, Match } from "solid-js"
 import { createStore } from "solid-js/store"
 import { useTheme } from "../../context/theme"
-import { Locale } from "@/util/locale"
-import path from "path"
 import type { AssistantMessage } from "@opencode-ai/sdk/v2"
-import { Global } from "@/global"
 import { Installation } from "@/installation"
-import { useKeybind } from "../../context/keybind"
-import { useDirectory } from "../../context/directory"
+import { Path } from "@/path/path"
 import { useKV } from "../../context/kv"
 import { TodoItem } from "../../component/todo-item"
+import { formatPath, formatServerPath, splitPath } from "../../util/path"
 
 export function Sidebar(props: { sessionID: string; overlay?: boolean }) {
   const sync = useSync()
@@ -29,6 +26,7 @@ export function Sidebar(props: { sessionID: string; overlay?: boolean }) {
 
   // Sort MCP servers alphabetically for consistent display order
   const mcpEntries = createMemo(() => Object.entries(sync.data.mcp).sort(([a], [b]) => a.localeCompare(b)))
+  const platform = createMemo(() => Path.platform(sync.data.path.os))
 
   // Count connected and error MCP servers for collapsed header display
   const connectedMcpCount = createMemo(() => mcpEntries().filter(([_, item]) => item.status === "connected").length)
@@ -60,8 +58,11 @@ export function Sidebar(props: { sessionID: string; overlay?: boolean }) {
     }
   })
 
-  const directory = useDirectory()
   const kv = useKV()
+  const dir = createMemo(() => {
+    return formatServerPath(sync.data.path.directory, sync.data.path)
+  })
+  const dirparts = createMemo(() => splitPath(dir(), { platform: platform() }))
 
   const hasProviders = createMemo(() =>
     sync.data.provider.some((x) => x.id !== "opencode" || Object.values(x.models).some((y) => y.cost?.input !== 0)),
@@ -203,7 +204,7 @@ export function Sidebar(props: { sessionID: string; overlay?: boolean }) {
                         •
                       </text>
                       <text fg={theme.textMuted}>
-                        {item.id} {item.root}
+                        {item.id} {formatPath(item.root, { home: sync.data.path.home, platform: platform() })}
                       </text>
                     </box>
                   )}
@@ -249,7 +250,7 @@ export function Sidebar(props: { sessionID: string; overlay?: boolean }) {
                       return (
                         <box flexDirection="row" gap={1} justifyContent="space-between">
                           <text fg={theme.textMuted} wrapMode="none">
-                            {item.file}
+                            {formatServerPath(item.file, sync.data.path)}
                           </text>
                           <box flexDirection="row" gap={1} flexShrink={0}>
                             <Show when={item.additions}>
@@ -304,8 +305,8 @@ export function Sidebar(props: { sessionID: string; overlay?: boolean }) {
             </box>
           </Show>
           <text>
-            <span style={{ fg: theme.textMuted }}>{directory().split("/").slice(0, -1).join("/")}/</span>
-            <span style={{ fg: theme.text }}>{directory().split("/").at(-1)}</span>
+            <span style={{ fg: theme.textMuted }}>{dirparts().dir}</span>
+            <span style={{ fg: theme.text }}>{dirparts().base || dir()}</span>
           </text>
           <text fg={theme.textMuted}>
             <span style={{ fg: theme.success }}>•</span> <b>Open</b>
diff --git a/packages/opencode/src/cli/cmd/tui/thread.ts b/packages/opencode/src/cli/cmd/tui/thread.ts
index 6e787c7afddd..b8fb76bc8894 100644
--- a/packages/opencode/src/cli/cmd/tui/thread.ts
+++ b/packages/opencode/src/cli/cmd/tui/thread.ts
@@ -14,6 +14,7 @@ import type { EventSource } from "./context/sdk"
 import { win32DisableProcessedInput, win32InstallCtrlCGuard } from "./win32"
 import { TuiConfig } from "@/config/tui"
 import { Instance } from "@/project/instance"
+import { Path } from "@/path/path"
 
 declare global {
   const OPENCODE_WORKER_PATH: string
@@ -113,12 +114,12 @@ export const TuiThreadCommand = cmd({
         return
       }
 
-      // Resolve relative --project paths from PWD, then use the real cwd after
-      // chdir so the thread and worker share the same directory key.
-      const root = Filesystem.resolve(process.env.PWD ?? process.cwd())
+      // Resolve relative --project paths from the logical shell root so alias
+      // roots from PWD or --project stay intact.
+      const root = Path.truecaseSync(process.env.PWD ?? process.cwd())
       const next = args.project
-        ? Filesystem.resolve(path.isAbsolute(args.project) ? args.project : path.join(root, args.project))
-        : Filesystem.resolve(process.cwd())
+        ? Path.truecaseSync(Path.isAbsolute(args.project) ? args.project : path.join(root, args.project))
+        : root
       const file = await target()
       try {
         process.chdir(next)
@@ -126,7 +127,7 @@ export const TuiThreadCommand = cmd({
         UI.error("Failed to change directory to " + next)
         return
       }
-      const cwd = Filesystem.resolve(process.cwd())
+      const cwd = next
 
       const worker = new Worker(file, {
         env: Object.fromEntries(
diff --git a/packages/opencode/src/cli/cmd/tui/util/path.ts b/packages/opencode/src/cli/cmd/tui/util/path.ts
new file mode 100644
index 000000000000..2cf1cd1a7b17
--- /dev/null
+++ b/packages/opencode/src/cli/cmd/tui/util/path.ts
@@ -0,0 +1,109 @@
+import path from "path"
+import { Path } from "@/path/path"
+
+type Opts = {
+  cwd?: string
+  home?: string
+  platform?: NodeJS.Platform | "windows" | "macos" | "linux"
+  relative?: boolean
+}
+
+type Server = {
+  directory?: string
+  home?: string
+  os?: Opts["platform"]
+}
+
+function pf(opts: Opts = {}) {
+  return Path.platform(opts.platform)
+}
+
+function lib(platform: NodeJS.Platform) {
+  return platform === "win32" ? path.win32 : path.posix
+}
+
+function text(input?: string) {
+  return input || undefined
+}
+
+export function serverPathOpts(input: Server, opts: Pick<Opts, "relative"> = {}): Opts {
+  const cwd = text(input.directory)
+  return {
+    cwd,
+    home: text(input.home),
+    platform: input.os,
+    relative: opts.relative && !!cwd,
+  }
+}
+
+export function formatServerPath(input: string | undefined, server: Server, opts: Pick<Opts, "relative"> = {}) {
+  if (!input) return ""
+
+  const cfg = serverPathOpts(server, opts)
+  const platform = pf(cfg)
+  if (cfg.cwd || Path.isAbsolute(input, { platform })) {
+    return formatPath(input, cfg)
+  }
+
+  if (platform === "win32") return path.win32.normalize(input)
+  return path.posix.normalize(input.replaceAll("\\", "/"))
+}
+
+export function serverPathKey(input: string, server: Server) {
+  const opts = serverPathOpts(server)
+  const platform = pf(opts)
+  if (opts.cwd || Path.isAbsolute(input, { platform })) {
+    return String(Path.key(input, { cwd: opts.cwd, platform }))
+  }
+
+  const text = String(Path.repo(input))
+  if (platform !== "win32") return text
+  return text.toLowerCase()
+}
+
+export function formatPath(input?: string, opts: Opts = {}) {
+  if (!input) return ""
+  return Path.display(input, {
+    cwd: opts.cwd,
+    home: opts.home ?? false,
+    platform: pf(opts),
+    relative: opts.relative,
+  })
+}
+
+export function splitPath(input: string, opts: Pick<Opts, "platform"> = {}) {
+  if (!input) return { dir: "", base: "" }
+
+  const mod = lib(pf(opts))
+  const parsed = mod.parse(input)
+  if (!parsed.base) return { dir: input, base: "" }
+  if (!parsed.dir) return { dir: "", base: parsed.base }
+
+  return {
+    dir: parsed.dir.endsWith(mod.sep) ? parsed.dir : parsed.dir + mod.sep,
+    base: parsed.base,
+  }
+}
+
+export function plugin(input: string, opts: Pick<Opts, "platform"> = {}) {
+  if (!input.startsWith("file://")) {
+    const idx = input.lastIndexOf("@")
+    if (idx <= 0) return { name: input, version: "latest" }
+    return {
+      name: input.substring(0, idx),
+      version: input.substring(idx + 1),
+    }
+  }
+
+  const platform = pf(opts)
+  const mod = lib(platform)
+  const text = String(Path.fromURI(input, { platform }))
+  const file = mod.basename(text)
+  const ext = mod.extname(file)
+  if (!ext) return { name: file }
+
+  const stem = file.slice(0, -ext.length)
+  if (stem !== "index") return { name: stem }
+
+  return { name: mod.basename(mod.dirname(text)) || stem }
+}
diff --git a/packages/opencode/src/cli/cmd/uninstall.ts b/packages/opencode/src/cli/cmd/uninstall.ts
index de41f32a0d14..eb8e4b02024a 100644
--- a/packages/opencode/src/cli/cmd/uninstall.ts
+++ b/packages/opencode/src/cli/cmd/uninstall.ts
@@ -8,6 +8,7 @@ import path from "path"
 import os from "os"
 import { Filesystem } from "../../util/filesystem"
 import { Process } from "../../util/process"
+import { Path } from "../../path/path"
 
 interface UninstallArgs {
   keepConfig: boolean
@@ -345,9 +346,5 @@ function formatSize(bytes: number): string {
 }
 
 function shortenPath(p: string): string {
-  const home = os.homedir()
-  if (p.startsWith(home)) {
-    return p.replace(home, "~")
-  }
-  return p
+  return Path.display(p)
 }
diff --git a/packages/opencode/src/config/paths.ts b/packages/opencode/src/config/paths.ts
index 396417e9a5bf..34280e8ddd3b 100644
--- a/packages/opencode/src/config/paths.ts
+++ b/packages/opencode/src/config/paths.ts
@@ -1,11 +1,11 @@
 import path from "path"
-import os from "os"
 import z from "zod"
 import { type ParseError as JsoncParseError, parse as parseJsonc, printParseErrorCode } from "jsonc-parser"
 import { NamedError } from "@opencode-ai/util/error"
 import { Filesystem } from "@/util/filesystem"
 import { Flag } from "@/flag/flag"
 import { Global } from "@/global"
+import { Path } from "@/path/path"
 
 export namespace ConfigPaths {
   export async function projectFiles(name: string, directory: string, worktree: string) {
@@ -78,7 +78,7 @@ export namespace ConfigPaths {
   }
 
   function dir(input: ParseSource) {
-    return typeof input === "string" ? path.dirname(input) : input.dir
+    return typeof input === "string" ? path.dirname(Path.pretty(input)) : input.dir
   }
 
   /** Apply {env:VAR} and {file:path} substitutions to config text. */
@@ -108,12 +108,8 @@ export namespace ConfigPaths {
         continue
       }
 
-      let filePath = token.replace(/^\{file:/, "").replace(/\}$/, "")
-      if (filePath.startsWith("~/")) {
-        filePath = path.join(os.homedir(), filePath.slice(2))
-      }
-
-      const resolvedPath = path.isAbsolute(filePath) ? filePath : path.resolve(configDir, filePath)
+      const filePath = Path.expand(token.replace(/^\{file:/, "").replace(/\}$/, ""))
+      const resolvedPath = Path.pretty(filePath, { cwd: configDir })
       const fileContent = (
         await Filesystem.readText(resolvedPath).catch((error: NodeJS.ErrnoException) => {
           if (missing === "empty") return ""
diff --git a/packages/opencode/src/control-plane/adaptors/worktree.ts b/packages/opencode/src/control-plane/adaptors/worktree.ts
index f84890950115..5d7ccfc4c234 100644
--- a/packages/opencode/src/control-plane/adaptors/worktree.ts
+++ b/packages/opencode/src/control-plane/adaptors/worktree.ts
@@ -1,6 +1,6 @@
 import z from "zod"
 import { Worktree } from "@/worktree"
-import { type Adaptor, WorkspaceInfo } from "../types"
+import { type Adaptor, type WorkspaceFetchInput, WorkspaceInfo } from "../types"
 
 const Config = WorkspaceInfo.extend({
   name: WorkspaceInfo.shape.name.unwrap(),
@@ -10,6 +10,16 @@ const Config = WorkspaceInfo.extend({
 
 type Config = z.infer<typeof Config>
 
+function config(info: WorkspaceInfo) {
+  return Config.parse(info)
+}
+
+function request(input: WorkspaceFetchInput, init?: RequestInit) {
+  const url = input instanceof URL ? input : input instanceof Request ? new URL(input.url) : new URL(input, "http://opencode.internal")
+  const headers = new Headers(init?.headers ?? (input instanceof Request ? input.headers : undefined))
+  return { url, headers }
+}
+
 export const WorktreeAdaptor: Adaptor = {
   async configure(info) {
     const worktree = await Worktree.makeWorktreeInfo(info.name ?? undefined)
@@ -21,26 +31,24 @@ export const WorktreeAdaptor: Adaptor = {
     }
   },
   async create(info) {
-    const config = Config.parse(info)
+    const cfg = config(info)
     const bootstrap = await Worktree.createFromInfo({
-      name: config.name,
-      directory: config.directory,
-      branch: config.branch,
+      name: cfg.name,
+      directory: cfg.directory,
+      branch: cfg.branch,
     })
     return bootstrap()
   },
   async remove(info) {
-    const config = Config.parse(info)
-    await Worktree.remove({ directory: config.directory })
+    await Worktree.remove({ directory: config(info).directory })
   },
-  async fetch(info, input: RequestInfo | URL, init?: RequestInit) {
-    const config = Config.parse(info)
+  async fetch(info, input, init) {
+    const cfg = config(info)
     const { WorkspaceServer } = await import("../workspace-server/server")
-    const url = input instanceof Request || input instanceof URL ? input : new URL(input, "http://opencode.internal")
-    const headers = new Headers(init?.headers ?? (input instanceof Request ? input.headers : undefined))
-    headers.set("x-opencode-directory", config.directory)
+    const req = request(input, init)
+    req.headers.set("x-opencode-workspace", cfg.id)
+    req.headers.set("x-opencode-directory", cfg.directory)
 
-    const request = new Request(url, { ...init, headers })
-    return WorkspaceServer.App().fetch(request)
+    return WorkspaceServer.App().fetch(new Request(req.url, { ...init, headers: req.headers }))
   },
 }
diff --git a/packages/opencode/src/control-plane/schema.ts b/packages/opencode/src/control-plane/schema.ts
index 7618f46ad4d4..68646408af1b 100644
--- a/packages/opencode/src/control-plane/schema.ts
+++ b/packages/opencode/src/control-plane/schema.ts
@@ -1,5 +1,4 @@
 import { Schema } from "effect"
-import z from "zod"
 
 import { withStatics } from "@/util/schema"
 import { Identifier } from "@/id/id"
@@ -11,7 +10,11 @@ export type WorkspaceID = typeof workspaceIdSchema.Type
 export const WorkspaceID = workspaceIdSchema.pipe(
   withStatics((schema: typeof workspaceIdSchema) => ({
     make: (id: string) => schema.makeUnsafe(id),
+    parse: (id: string) => schema.makeUnsafe(Identifier.parse("workspace", id)),
+    assert: (id: string): asserts id is WorkspaceID => {
+      Identifier.assert("workspace", id)
+    },
     ascending: (id?: string) => schema.makeUnsafe(Identifier.ascending("workspace", id)),
-    zod: Identifier.schema("workspace").pipe(z.custom<WorkspaceID>()),
+    zod: Identifier.schema<WorkspaceID>("workspace"),
   })),
 )
diff --git a/packages/opencode/src/control-plane/types.ts b/packages/opencode/src/control-plane/types.ts
index ab628a693814..b806c29e6675 100644
--- a/packages/opencode/src/control-plane/types.ts
+++ b/packages/opencode/src/control-plane/types.ts
@@ -1,4 +1,5 @@
 import z from "zod"
+import { PrettyPath } from "@/path/schema"
 import { ProjectID } from "@/project/schema"
 import { WorkspaceID } from "./schema"
 
@@ -7,15 +8,17 @@ export const WorkspaceInfo = z.object({
   type: z.string(),
   branch: z.string().nullable(),
   name: z.string().nullable(),
-  directory: z.string().nullable(),
+  directory: PrettyPath.zod.nullable(),
   extra: z.unknown().nullable(),
   projectID: ProjectID.zod,
 })
 export type WorkspaceInfo = z.infer<typeof WorkspaceInfo>
 
+export type WorkspaceFetchInput = string | URL | Request
+
 export type Adaptor = {
   configure(input: WorkspaceInfo): WorkspaceInfo | Promise<WorkspaceInfo>
   create(input: WorkspaceInfo, from?: WorkspaceInfo): Promise<void>
   remove(config: WorkspaceInfo): Promise<void>
-  fetch(config: WorkspaceInfo, input: RequestInfo | URL, init?: RequestInit): Promise<Response>
+  fetch(config: WorkspaceInfo, input: WorkspaceFetchInput, init?: RequestInit): Promise<Response>
 }
diff --git a/packages/opencode/src/control-plane/workspace-server/server.ts b/packages/opencode/src/control-plane/workspace-server/server.ts
index b0744fe025bb..074b98185e74 100644
--- a/packages/opencode/src/control-plane/workspace-server/server.ts
+++ b/packages/opencode/src/control-plane/workspace-server/server.ts
@@ -5,6 +5,14 @@ import { SessionRoutes } from "../../server/routes/session"
 import { WorkspaceServerRoutes } from "./routes"
 import { WorkspaceContext } from "../workspace-context"
 import { WorkspaceID } from "../schema"
+import { Path } from "../../path/path"
+import { HTTPException } from "hono/http-exception"
+
+function badInput(err: unknown) {
+  return new HTTPException(400, {
+    message: err instanceof Error ? err.message : "Invalid request",
+  })
+}
 
 export namespace WorkspaceServer {
   export function App() {
@@ -24,22 +32,29 @@ export namespace WorkspaceServer {
         const rawWorkspaceID = c.req.query("workspace") || c.req.header("x-opencode-workspace")
         const raw = c.req.query("directory") || c.req.header("x-opencode-directory")
         if (rawWorkspaceID == null) {
-          throw new Error("workspaceID parameter is required")
+          throw new HTTPException(400, { message: "workspace parameter is required" })
         }
         if (raw == null) {
-          throw new Error("directory parameter is required")
+          throw new HTTPException(400, { message: "directory parameter is required" })
         }
 
+        const workspaceID = (() => {
+          try {
+            return WorkspaceID.parse(rawWorkspaceID)
+          } catch (err) {
+            throw badInput(err)
+          }
+        })()
         const directory = (() => {
           try {
-            return decodeURIComponent(raw)
-          } catch {
-            return raw
+            return Path.ingress(raw, { label: "directory parameter" })
+          } catch (err) {
+            throw badInput(err)
           }
         })()
 
         return WorkspaceContext.provide({
-          workspaceID: WorkspaceID.make(rawWorkspaceID),
+          workspaceID,
           async fn() {
             return Instance.provide({
               directory,
diff --git a/packages/opencode/src/control-plane/workspace.sql.ts b/packages/opencode/src/control-plane/workspace.sql.ts
index 272907da1500..df3655bdb95f 100644
--- a/packages/opencode/src/control-plane/workspace.sql.ts
+++ b/packages/opencode/src/control-plane/workspace.sql.ts
@@ -1,6 +1,7 @@
 import { sqliteTable, text } from "drizzle-orm/sqlite-core"
 import { ProjectTable } from "../project/project.sql"
 import type { ProjectID } from "../project/schema"
+import type { PrettyPath } from "../path/schema"
 import type { WorkspaceID } from "./schema"
 
 export const WorkspaceTable = sqliteTable("workspace", {
@@ -8,7 +9,7 @@ export const WorkspaceTable = sqliteTable("workspace", {
   type: text().notNull(),
   branch: text(),
   name: text(),
-  directory: text(),
+  directory: text().$type<PrettyPath>(),
   extra: text({ mode: "json" }),
   project_id: text()
     .$type<ProjectID>()
diff --git a/packages/opencode/src/control-plane/workspace.ts b/packages/opencode/src/control-plane/workspace.ts
index e5294844b148..765002e28dd8 100644
--- a/packages/opencode/src/control-plane/workspace.ts
+++ b/packages/opencode/src/control-plane/workspace.ts
@@ -12,6 +12,7 @@ import { getAdaptor } from "./adaptors"
 import { WorkspaceInfo } from "./types"
 import { WorkspaceID } from "./schema"
 import { parseSSE } from "./sse"
+import { Path } from "@/path/path"
 
 export namespace Workspace {
   export const Event = {
@@ -32,7 +33,7 @@ export namespace Workspace {
   export const Info = WorkspaceInfo.meta({
     ref: "Workspace",
   })
-  export type Info = z.infer<typeof Info>
+  export type Info = WorkspaceInfo
 
   function fromRow(row: typeof WorkspaceTable.$inferSelect): Info {
     return {
@@ -40,7 +41,7 @@ export namespace Workspace {
       type: row.type,
       branch: row.branch,
       name: row.name,
-      directory: row.directory,
+      directory: row.directory ? Path.truecaseSync(row.directory) : null,
       extra: row.extra,
       projectID: row.project_id,
     }
@@ -59,13 +60,14 @@ export namespace Workspace {
     const adaptor = await getAdaptor(input.type)
 
     const config = await adaptor.configure({ ...input, id, name: null, directory: null })
+    const dir = config.directory ? await Path.truecase(config.directory) : null
 
     const info: Info = {
       id,
       type: config.type,
       branch: config.branch ?? null,
       name: config.name ?? null,
-      directory: config.directory ?? null,
+      directory: dir,
       extra: config.extra ?? null,
       projectID: input.projectID,
     }
@@ -106,7 +108,7 @@ export namespace Workspace {
     if (row) {
       const info = fromRow(row)
       const adaptor = await getAdaptor(row.type)
-      adaptor.remove(info)
+      await adaptor.remove(info)
       Database.use((db) => db.delete(WorkspaceTable).where(eq(WorkspaceTable.id, id)).run())
       return info
     }
diff --git a/packages/opencode/src/effect/instance-context.ts b/packages/opencode/src/effect/instance-context.ts
index fd4590190496..625bcab2b294 100644
--- a/packages/opencode/src/effect/instance-context.ts
+++ b/packages/opencode/src/effect/instance-context.ts
@@ -1,10 +1,11 @@
 import { ServiceMap } from "effect"
+import type { PrettyPath } from "@/path/schema"
 import type { Project } from "@/project/project"
 
 export declare namespace InstanceContext {
   export interface Shape {
-    readonly directory: string
-    readonly worktree: string
+    readonly directory: PrettyPath
+    readonly worktree: PrettyPath
     readonly project: Project.Info
   }
 }
diff --git a/packages/opencode/src/effect/instance-registry.ts b/packages/opencode/src/effect/instance-registry.ts
index 59c556e0447e..1c8e1c83c23f 100644
--- a/packages/opencode/src/effect/instance-registry.ts
+++ b/packages/opencode/src/effect/instance-registry.ts
@@ -1,12 +1,14 @@
-const disposers = new Set<(directory: string) => Promise<void>>()
+import type { PrettyPath } from "@/path/schema"
 
-export function registerDisposer(disposer: (directory: string) => Promise<void>) {
+const disposers = new Set<(directory: PrettyPath) => Promise<void>>()
+
+export function registerDisposer(disposer: (directory: PrettyPath) => Promise<void>) {
   disposers.add(disposer)
   return () => {
     disposers.delete(disposer)
   }
 }
 
-export async function disposeInstance(directory: string) {
+export async function disposeInstance(directory: PrettyPath) {
   await Promise.allSettled([...disposers].map((disposer) => disposer(directory)))
 }
diff --git a/packages/opencode/src/file/index.ts b/packages/opencode/src/file/index.ts
index 23c77e7bf713..7432eaeddbbc 100644
--- a/packages/opencode/src/file/index.ts
+++ b/packages/opencode/src/file/index.ts
@@ -1,4 +1,6 @@
 import { BusEvent } from "@/bus/bus-event"
+import { Path } from "@/path/path"
+import { Instance } from "@/project/instance"
 import { InstanceState } from "@/effect/instance-state"
 import { makeRunPromise } from "@/effect/run-service"
 import { git } from "@/util/git"
@@ -10,13 +12,16 @@ import ignore from "ignore"
 import path from "path"
 import z from "zod"
 import { Global } from "../global"
-import { Instance } from "../project/instance"
 import { Filesystem } from "../util/filesystem"
 import { Log } from "../util/log"
 import { Protected } from "./protected"
 import { Ripgrep } from "./ripgrep"
+import type { PrettyPath, RepoPath } from "@/path/schema"
 
 export namespace File {
+  const repo = (input: RepoPath | string) =>
+    Path.isAbsolute(input) ? Path.repoFrom(Instance.directory, input) : Path.repo(input)
+
   export const Info = z
     .object({
       path: z.string(),
@@ -28,7 +33,9 @@ export namespace File {
       ref: "File",
     })
 
-  export type Info = z.infer<typeof Info>
+  export type Info = Omit<z.infer<typeof Info>, "path"> & {
+    path: RepoPath
+  }
 
   export const Node = z
     .object({
@@ -41,7 +48,10 @@ export namespace File {
     .meta({
       ref: "FileNode",
     })
-  export type Node = z.infer<typeof Node>
+  export type Node = Omit<z.infer<typeof Node>, "path" | "absolute"> & {
+    path: RepoPath
+    absolute: PrettyPath
+  }
 
   export const Content = z
     .object({
@@ -284,7 +294,7 @@ export namespace File {
     heif: "image/heif",
   }
 
-  type Entry = { files: string[]; dirs: string[] }
+  type Entry = { files: RepoPath[]; dirs: RepoPath[] }
 
   const ext = (file: string) => path.extname(file).toLowerCase().slice(1)
   const name = (file: string) => path.basename(file).toLowerCase()
@@ -305,23 +315,20 @@ export namespace File {
     return ["image", "audio", "video", "font", "model", "multipart"].includes(top)
   }
 
-  const hidden = (item: string) => {
-    const normalized = item.replaceAll("\\", "/").replace(/\/+$/, "")
-    return normalized.split("/").some((part) => part.startsWith(".") && part.length > 1)
-  }
-
-  const sortHiddenLast = (items: string[], prefer: boolean) => {
+  const sortHiddenLast = <T extends string>(items: T[], prefer: boolean) => {
     if (prefer) return items
-    const visible: string[] = []
-    const hiddenItems: string[] = []
+    const visible: T[] = []
+    const hiddenItems: T[] = []
     for (const item of items) {
-      if (hidden(item)) hiddenItems.push(item)
+      if (Path.hidden(item)) hiddenItems.push(item)
       else visible.push(item)
     }
     return [...visible, ...hiddenItems]
   }
 
   interface State {
+    root: Promise<PrettyPath>
+    worktree: Promise<PrettyPath | undefined>
     cache: Entry
     fiber: Fiber.Fiber<void> | undefined
   }
@@ -329,14 +336,14 @@ export namespace File {
   export interface Interface {
     readonly init: () => Effect.Effect<void>
     readonly status: () => Effect.Effect<File.Info[]>
-    readonly read: (file: string) => Effect.Effect<File.Content>
-    readonly list: (dir?: string) => Effect.Effect<File.Node[]>
+    readonly read: (file: RepoPath) => Effect.Effect<File.Content>
+    readonly list: (dir?: RepoPath) => Effect.Effect<File.Node[]>
     readonly search: (input: {
       query: string
       limit?: number
       dirs?: boolean
       type?: "file" | "directory"
-    }) => Effect.Effect<string[]>
+    }) => Effect.Effect<RepoPath[]>
   }
 
   export class Service extends ServiceMap.Service<Service, Interface>()("@opencode/File") {}
@@ -344,15 +351,25 @@ export namespace File {
   export const layer = Layer.effect(
     Service,
     Effect.gen(function* () {
-      const state = yield* InstanceState.make<State>(
-        Effect.fn("File.state")(() =>
+      const store = yield* InstanceState.make<State>(
+        Effect.fn("File.state")((ctx) =>
           Effect.succeed({
+            root: Path.physical(ctx.directory),
+            worktree: ctx.worktree === "/" ? Promise.resolve(undefined) : Path.physical(ctx.worktree),
             cache: { files: [], dirs: [] } as Entry,
             fiber: undefined as Fiber.Fiber<void> | undefined,
           }),
         ),
       )
 
+      const allow = async (state: State, input: string) => {
+        const file = await Path.physical(input)
+        if (Path.contains(await state.root, file)) return true
+        const worktree = await state.worktree
+        if (!worktree) return false
+        return Path.contains(worktree, file)
+      }
+
       const scan = Effect.fn("File.scan")(function* () {
         if (Instance.directory === path.parse(Instance.directory).root) return
         const isGlobalHome = Instance.directory === Global.Path.home && Instance.project.id === "global"
@@ -360,7 +377,7 @@ export namespace File {
 
         yield* Effect.promise(async () => {
           if (isGlobalHome) {
-            const dirs = new Set<string>()
+            const dirs = new Set<RepoPath>()
             const protectedNames = Protected.names()
             const ignoreNested = new Set(["node_modules", "dist", "build", "target", "vendor"])
             const shouldIgnoreName = (name: string) => name.startsWith(".") || protectedNames.has(name)
@@ -372,14 +389,14 @@ export namespace File {
             for (const entry of top) {
               if (!entry.isDirectory()) continue
               if (shouldIgnoreName(entry.name)) continue
-              dirs.add(entry.name + "/")
+              dirs.add(Path.repo(`${entry.name}/`))
 
               const base = path.join(Instance.directory, entry.name)
               const children = await fs.promises.readdir(base, { withFileTypes: true }).catch(() => [] as fs.Dirent[])
               for (const child of children) {
                 if (!child.isDirectory()) continue
                 if (shouldIgnoreNested(child.name)) continue
-                dirs.add(entry.name + "/" + child.name + "/")
+                dirs.add(Path.repo(`${entry.name}/${child.name}/`))
               }
             }
 
@@ -387,29 +404,31 @@ export namespace File {
           } else {
             const seen = new Set<string>()
             for await (const file of Ripgrep.files({ cwd: Instance.directory })) {
-              next.files.push(file)
-              let current = file
-              while (true) {
-                const dir = path.dirname(current)
-                if (dir === ".") break
-                if (dir === current) break
-                current = dir
-                if (seen.has(dir)) continue
-                seen.add(dir)
-                next.dirs.push(dir + "/")
+              const key = Path.repo(file)
+              next.files.push(key)
+              let dir = Path.repoParent(key)
+              while (dir !== ".") {
+                const item = Path.repo(`${dir}/`)
+                if (seen.has(item)) {
+                  dir = Path.repoParent(dir)
+                  continue
+                }
+                seen.add(item)
+                next.dirs.push(item)
+                dir = Path.repoParent(dir)
               }
             }
           }
         })
 
-        const s = yield* InstanceState.get(state)
+        const s = yield* InstanceState.get(store)
         s.cache = next
       })
 
       const scope = yield* Scope.Scope
 
       const ensure = Effect.fn("File.ensure")(function* () {
-        const s = yield* InstanceState.get(state)
+        const s = yield* InstanceState.get(store)
         if (!s.fiber)
           s.fiber = yield* scan().pipe(
             Effect.catchCause(() => Effect.void),
@@ -437,7 +456,7 @@ export namespace File {
             })
           ).text()
 
-          const changed: File.Info[] = []
+          const changed: Array<Omit<File.Info, "path"> & { path: string }> = []
 
           if (diffOutput.trim()) {
             for (const line of diffOutput.trim().split("\n")) {
@@ -517,19 +536,20 @@ export namespace File {
             const full = path.isAbsolute(item.path) ? item.path : path.join(Instance.directory, item.path)
             return {
               ...item,
-              path: path.relative(Instance.directory, full),
+              path: Path.repoFrom(Instance.directory, full),
             }
           })
         })
       })
 
-      const read = Effect.fn("File.read")(function* (file: string) {
+      const read = Effect.fn("File.read")(function* (file: RepoPath) {
+        const state = yield* InstanceState.get(store)
         return yield* Effect.promise(async (): Promise<File.Content> => {
           using _ = log.time("read", { file })
-          const full = path.join(Instance.directory, file)
+          const full = Path.join(Instance.directory, file)
 
-          if (!Instance.containsPath(full)) {
-            throw new Error("Access denied: path escapes project directory")
+          if (!(await allow(state, full))) {
+            throw new Error(`Access denied: path escapes project directory`)
           }
 
           if (isImageByExtension(file)) {
@@ -604,7 +624,8 @@ export namespace File {
         })
       })
 
-      const list = Effect.fn("File.list")(function* (dir?: string) {
+      const list = Effect.fn("File.list")(function* (dir?: RepoPath) {
+        const state = yield* InstanceState.get(store)
         return yield* Effect.promise(async () => {
           const exclude = [".git", ".DS_Store"]
           let ignored = (_: string) => false
@@ -621,23 +642,23 @@ export namespace File {
             ignored = ig.ignores.bind(ig)
           }
 
-          const resolved = dir ? path.join(Instance.directory, dir) : Instance.directory
-          if (!Instance.containsPath(resolved)) {
+          const resolved = dir ? Path.join(Instance.directory, dir) : Instance.directory
+          if (!(await allow(state, resolved))) {
             throw new Error("Access denied: path escapes project directory")
           }
 
           const nodes: File.Node[] = []
           for (const entry of await fs.promises.readdir(resolved, { withFileTypes: true }).catch(() => [])) {
             if (exclude.includes(entry.name)) continue
-            const absolute = path.join(resolved, entry.name)
-            const file = path.relative(Instance.directory, absolute)
+            const absolute = Path.join(resolved, entry.name)
+            const file = Path.repoFrom(Instance.directory, absolute)
             const type = entry.isDirectory() ? "directory" : "file"
             nodes.push({
               name: entry.name,
               path: file,
               absolute,
               type,
-              ignored: ignored(type === "directory" ? file + "/" : file),
+              ignored: ignored(type === "directory" ? Path.repo(`${file}/`) : file),
             })
           }
 
@@ -655,7 +676,7 @@ export namespace File {
         type?: "file" | "directory"
       }) {
         yield* ensure()
-        const { cache } = yield* InstanceState.get(state)
+        const { cache } = yield* InstanceState.get(store)
 
         return yield* Effect.promise(async () => {
           const query = input.query.trim()
@@ -679,7 +700,7 @@ export namespace File {
           const output = kind === "directory" ? sortHiddenLast(sorted, preferHidden).slice(0, limit) : sorted
 
           log.info("search", { query, kind, results: output.length })
-          return output
+          return output as RepoPath[]
         })
       })
 
@@ -698,12 +719,12 @@ export namespace File {
     return runPromise((svc) => svc.status())
   }
 
-  export async function read(file: string): Promise<Content> {
-    return runPromise((svc) => svc.read(file))
+  export async function read(file: RepoPath | string): Promise<Content> {
+    return runPromise((svc) => svc.read(repo(file)))
   }
 
-  export async function list(dir?: string) {
-    return runPromise((svc) => svc.list(dir))
+  export async function list(dir?: RepoPath | string) {
+    return runPromise((svc) => svc.list(dir ? repo(dir) : undefined))
   }
 
   export async function search(input: { query: string; limit?: number; dirs?: boolean; type?: "file" | "directory" }) {
diff --git a/packages/opencode/src/file/time.ts b/packages/opencode/src/file/time.ts
index 4962ef0c9eef..8f2a1b2ad617 100644
--- a/packages/opencode/src/file/time.ts
+++ b/packages/opencode/src/file/time.ts
@@ -2,6 +2,8 @@ import { DateTime, Effect, Layer, Semaphore, ServiceMap } from "effect"
 import { InstanceState } from "@/effect/instance-state"
 import { makeRunPromise } from "@/effect/run-service"
 import { Flag } from "@/flag/flag"
+import { Path } from "@/path/path"
+import type { PathKey, PrettyPath } from "@/path/schema"
 import type { SessionID } from "@/session/schema"
 import { Filesystem } from "../util/filesystem"
 import { Log } from "../util/log"
@@ -10,16 +12,20 @@ export namespace FileTime {
   const log = Log.create({ service: "file.time" })
 
   export type Stamp = {
+    readonly file: PrettyPath
     readonly read: Date
     readonly mtime: number | undefined
     readonly ctime: number | undefined
     readonly size: number | undefined
   }
 
-  const stamp = Effect.fnUntraced(function* (file: string) {
+  const key = (file: PrettyPath) => Path.key(file)
+
+  const stamp = Effect.fnUntraced(function* (file: PrettyPath) {
     const stat = Filesystem.stat(file)
     const size = typeof stat?.size === "bigint" ? Number(stat.size) : stat?.size
     return {
+      file,
       read: yield* DateTime.nowAsDate,
       mtime: stat?.mtime?.getTime(),
       ctime: stat?.ctime?.getTime(),
@@ -27,25 +33,25 @@ export namespace FileTime {
     }
   })
 
-  const session = (reads: Map<SessionID, Map<string, Stamp>>, sessionID: SessionID) => {
+  const session = (reads: Map<SessionID, Map<PathKey, Stamp>>, sessionID: SessionID) => {
     const value = reads.get(sessionID)
     if (value) return value
 
-    const next = new Map<string, Stamp>()
+    const next = new Map<PathKey, Stamp>()
     reads.set(sessionID, next)
     return next
   }
 
   interface State {
-    reads: Map<SessionID, Map<string, Stamp>>
-    locks: Map<string, Semaphore.Semaphore>
+    reads: Map<SessionID, Map<PathKey, Stamp>>
+    locks: Map<PathKey, Semaphore.Semaphore>
   }
 
   export interface Interface {
-    readonly read: (sessionID: SessionID, file: string) => Effect.Effect<void>
-    readonly get: (sessionID: SessionID, file: string) => Effect.Effect<Date | undefined>
-    readonly assert: (sessionID: SessionID, filepath: string) => Effect.Effect<void>
-    readonly withLock: <T>(filepath: string, fn: () => Promise<T>) => Effect.Effect<T>
+    readonly read: (sessionID: SessionID, file: PrettyPath) => Effect.Effect<void>
+    readonly get: (sessionID: SessionID, file: PrettyPath) => Effect.Effect<Date | undefined>
+    readonly assert: (sessionID: SessionID, file: PrettyPath) => Effect.Effect<void>
+    readonly withLock: <T>(file: PrettyPath, fn: () => Promise<T>) => Effect.Effect<T>
   }
 
   export class Service extends ServiceMap.Service<Service, Interface>()("@opencode/FileTime") {}
@@ -53,55 +59,56 @@ export namespace FileTime {
   export const layer = Layer.effect(
     Service,
     Effect.gen(function* () {
-      const disableCheck = yield* Flag.OPENCODE_DISABLE_FILETIME_CHECK
+      const disable = yield* Flag.OPENCODE_DISABLE_FILETIME_CHECK
       const state = yield* InstanceState.make<State>(
         Effect.fn("FileTime.state")(() =>
           Effect.succeed({
-            reads: new Map<SessionID, Map<string, Stamp>>(),
-            locks: new Map<string, Semaphore.Semaphore>(),
+            reads: new Map<SessionID, Map<PathKey, Stamp>>(),
+            locks: new Map<PathKey, Semaphore.Semaphore>(),
           }),
         ),
       )
 
-      const getLock = Effect.fn("FileTime.lock")(function* (filepath: string) {
+      const lock = Effect.fn("FileTime.lock")(function* (file: PrettyPath) {
         const locks = (yield* InstanceState.get(state)).locks
-        const lock = locks.get(filepath)
-        if (lock) return lock
+        const id = key(file)
+        const existing = locks.get(id)
+        if (existing) return existing
 
         const next = Semaphore.makeUnsafe(1)
-        locks.set(filepath, next)
+        locks.set(id, next)
         return next
       })
 
-      const read = Effect.fn("FileTime.read")(function* (sessionID: SessionID, file: string) {
+      const read = Effect.fn("FileTime.read")(function* (sessionID: SessionID, file: PrettyPath) {
         const reads = (yield* InstanceState.get(state)).reads
         log.info("read", { sessionID, file })
-        session(reads, sessionID).set(file, yield* stamp(file))
+        session(reads, sessionID).set(key(file), yield* stamp(file))
       })
 
-      const get = Effect.fn("FileTime.get")(function* (sessionID: SessionID, file: string) {
+      const get = Effect.fn("FileTime.get")(function* (sessionID: SessionID, file: PrettyPath) {
         const reads = (yield* InstanceState.get(state)).reads
-        return reads.get(sessionID)?.get(file)?.read
+        return reads.get(sessionID)?.get(key(file))?.read
       })
 
-      const assert = Effect.fn("FileTime.assert")(function* (sessionID: SessionID, filepath: string) {
-        if (disableCheck) return
+      const assert = Effect.fn("FileTime.assert")(function* (sessionID: SessionID, file: PrettyPath) {
+        if (disable) return
 
         const reads = (yield* InstanceState.get(state)).reads
-        const time = reads.get(sessionID)?.get(filepath)
-        if (!time) throw new Error(`You must read file ${filepath} before overwriting it. Use the Read tool first`)
+        const time = reads.get(sessionID)?.get(key(file))
+        if (!time) throw new Error(`You must read file ${file} before overwriting it. Use the Read tool first`)
 
-        const next = yield* stamp(filepath)
+        const next = yield* stamp(file)
         const changed = next.mtime !== time.mtime || next.ctime !== time.ctime || next.size !== time.size
         if (!changed) return
 
         throw new Error(
-          `File ${filepath} has been modified since it was last read.\nLast modification: ${new Date(next.mtime ?? next.read.getTime()).toISOString()}\nLast read: ${time.read.toISOString()}\n\nPlease read the file again before modifying it.`,
+          `File ${file} has been modified since it was last read.\nLast modification: ${new Date(next.mtime ?? next.read.getTime()).toISOString()}\nLast read: ${time.read.toISOString()}\n\nPlease read the file again before modifying it.`,
         )
       })
 
-      const withLock = Effect.fn("FileTime.withLock")(function* <T>(filepath: string, fn: () => Promise<T>) {
-        return yield* Effect.promise(fn).pipe((yield* getLock(filepath)).withPermits(1))
+      const withLock = Effect.fn("FileTime.withLock")(function* <T>(file: PrettyPath, fn: () => Promise<T>) {
+        return yield* Effect.promise(fn).pipe((yield* lock(file)).withPermits(1))
       })
 
       return Service.of({ read, get, assert, withLock })
@@ -110,19 +117,19 @@ export namespace FileTime {
 
   const runPromise = makeRunPromise(Service, layer)
 
-  export function read(sessionID: SessionID, file: string) {
+  export function read(sessionID: SessionID, file: PrettyPath) {
     return runPromise((s) => s.read(sessionID, file))
   }
 
-  export function get(sessionID: SessionID, file: string) {
+  export function get(sessionID: SessionID, file: PrettyPath) {
     return runPromise((s) => s.get(sessionID, file))
   }
 
-  export async function assert(sessionID: SessionID, filepath: string) {
-    return runPromise((s) => s.assert(sessionID, filepath))
+  export async function assert(sessionID: SessionID, file: PrettyPath) {
+    return runPromise((s) => s.assert(sessionID, file))
   }
 
-  export async function withLock<T>(filepath: string, fn: () => Promise<T>): Promise<T> {
-    return runPromise((s) => s.withLock(filepath, fn))
+  export async function withLock<T>(file: PrettyPath, fn: () => Promise<T>): Promise<T> {
+    return runPromise((s) => s.withLock(file, fn))
   }
 }
diff --git a/packages/opencode/src/file/watcher.ts b/packages/opencode/src/file/watcher.ts
index 1b3fc8ab4f2d..213125617979 100644
--- a/packages/opencode/src/file/watcher.ts
+++ b/packages/opencode/src/file/watcher.ts
@@ -1,15 +1,16 @@
-import { Cause, Effect, Layer, Scope, ServiceMap } from "effect"
+import { Cause, Effect, Layer, ServiceMap } from "effect"
 // @ts-ignore
 import { createWrapper } from "@parcel/watcher/wrapper"
 import type ParcelWatcher from "@parcel/watcher"
-import { readdir } from "fs/promises"
 import path from "path"
+import { readdir } from "fs/promises"
 import z from "zod"
 import { Bus } from "@/bus"
 import { BusEvent } from "@/bus/bus-event"
 import { InstanceState } from "@/effect/instance-state"
 import { makeRunPromise } from "@/effect/run-service"
 import { Flag } from "@/flag/flag"
+import { Path } from "@/path/path"
 import { Instance } from "@/project/instance"
 import { git } from "@/util/git"
 import { lazy } from "@/util/lazy"
@@ -53,10 +54,7 @@ export namespace FileWatcher {
   }
 
   function protecteds(dir: string) {
-    return Protected.paths().filter((item) => {
-      const rel = path.relative(dir, item)
-      return rel !== "" && !rel.startsWith("..") && !path.isAbsolute(rel)
-    })
+    return Protected.paths().filter((item) => Path.contains(dir, item) && !Path.eq(dir, item))
   }
 
   export const hasNativeBinding = () => !!watcher()
@@ -111,19 +109,19 @@ export namespace FileWatcher {
                 Effect.timeout(SUBSCRIBE_TIMEOUT_MS),
                 Effect.catchCause((cause) => {
                   log.error("failed to subscribe", { dir, cause: Cause.pretty(cause) })
-                  pending.then((s) => s.unsubscribe()).catch(() => {})
+                  pending.then((sub) => sub.unsubscribe()).catch(() => {})
                   return Effect.void
                 }),
               )
             }
 
             const cfg = yield* Effect.promise(() => Config.get())
-            const cfgIgnores = cfg.watcher?.ignore ?? []
+            const ignores = cfg.watcher?.ignore ?? []
 
             if (yield* Flag.OPENCODE_EXPERIMENTAL_FILEWATCHER) {
               yield* subscribe(Instance.directory, [
                 ...FileIgnore.PATTERNS,
-                ...cfgIgnores,
+                ...ignores,
                 ...protecteds(Instance.directory),
               ])
             }
@@ -136,7 +134,7 @@ export namespace FileWatcher {
               )
               const vcsDir =
                 result.exitCode === 0 ? path.resolve(Instance.project.worktree, result.text().trim()) : undefined
-              if (vcsDir && !cfgIgnores.includes(".git") && !cfgIgnores.includes(vcsDir)) {
+              if (vcsDir && !ignores.includes(".git") && !ignores.includes(vcsDir)) {
                 const ignore = (yield* Effect.promise(() => readdir(vcsDir).catch(() => []))).filter(
                   (entry) => entry !== "HEAD",
                 )
diff --git a/packages/opencode/src/filesystem/index.ts b/packages/opencode/src/filesystem/index.ts
index d8f7d6053e71..9aa2f95e3550 100644
--- a/packages/opencode/src/filesystem/index.ts
+++ b/packages/opencode/src/filesystem/index.ts
@@ -1,10 +1,10 @@
 import { NodeFileSystem } from "@effect/platform-node"
-import { dirname, join, relative, resolve as pathResolve } from "path"
-import { realpathSync } from "fs"
-import { lookup } from "mime-types"
+import { dirname } from "path"
 import { Effect, FileSystem, Layer, Schema, ServiceMap } from "effect"
 import type { PlatformError } from "effect/PlatformError"
+import { Path } from "../path/path"
 import { Glob } from "../util/glob"
+import { Filesystem as LocalFilesystem } from "../util/filesystem"
 
 export namespace AppFileSystem {
   export class FileSystemError extends Schema.TaggedErrorClass<FileSystemError>()("FileSystemError", {
@@ -87,48 +87,32 @@ export namespace AppFileSystem {
         })
       })
 
-      const findUp = Effect.fn("FileSystem.findUp")(function* (target: string, start: string, stop?: string) {
+      const collectUp = Effect.fnUntraced(function* (targets: string[], start: string, stop?: string) {
         const result: string[] = []
-        let current = start
-        while (true) {
-          const search = join(current, target)
-          if (yield* fs.exists(search)) result.push(search)
-          if (stop === current) break
-          const parent = dirname(current)
-          if (parent === current) break
-          current = parent
+        for (const dir of Path.up(start, { stop })) {
+          for (const target of targets) {
+            const file = Path.join(dir, target)
+            if (yield* fs.exists(file)) result.push(file)
+          }
         }
         return result
       })
 
+      const findUp = Effect.fn("FileSystem.findUp")(function* (target: string, start: string, stop?: string) {
+        return yield* collectUp([target], start, stop)
+      })
+
       const up = Effect.fn("FileSystem.up")(function* (options: { targets: string[]; start: string; stop?: string }) {
-        const result: string[] = []
-        let current = options.start
-        while (true) {
-          for (const target of options.targets) {
-            const search = join(current, target)
-            if (yield* fs.exists(search)) result.push(search)
-          }
-          if (options.stop === current) break
-          const parent = dirname(current)
-          if (parent === current) break
-          current = parent
-        }
-        return result
+        return yield* collectUp(options.targets, options.start, options.stop)
       })
 
       const globUp = Effect.fn("FileSystem.globUp")(function* (pattern: string, start: string, stop?: string) {
         const result: string[] = []
-        let current = start
-        while (true) {
-          const matches = yield* glob(pattern, { cwd: current, absolute: true, include: "file", dot: true }).pipe(
+        for (const dir of Path.up(start, { stop })) {
+          const matches = yield* glob(pattern, { cwd: dir, absolute: true, include: "file", dot: true }).pipe(
             Effect.catch(() => Effect.succeed([] as string[])),
           )
           result.push(...matches)
-          if (stop === current) break
-          const parent = dirname(current)
-          if (parent === current) break
-          current = parent
         }
         return result
       })
@@ -152,46 +136,8 @@ export namespace AppFileSystem {
 
   export const defaultLayer = layer.pipe(Layer.provide(NodeFileSystem.layer))
 
-  // Pure helpers that don't need Effect (path manipulation, sync operations)
+  // Pure helper that doesn't need Effect.
   export function mimeType(p: string): string {
-    return lookup(p) || "application/octet-stream"
-  }
-
-  export function normalizePath(p: string): string {
-    if (process.platform !== "win32") return p
-    try {
-      return realpathSync.native(p)
-    } catch {
-      return p
-    }
-  }
-
-  export function resolve(p: string): string {
-    const resolved = pathResolve(windowsPath(p))
-    try {
-      return normalizePath(realpathSync(resolved))
-    } catch (e: any) {
-      if (e?.code === "ENOENT") return normalizePath(resolved)
-      throw e
-    }
-  }
-
-  export function windowsPath(p: string): string {
-    if (process.platform !== "win32") return p
-    return p
-      .replace(/^\/([a-zA-Z]):(?:[\\/]|$)/, (_, drive) => `${drive.toUpperCase()}:/`)
-      .replace(/^\/([a-zA-Z])(?:\/|$)/, (_, drive) => `${drive.toUpperCase()}:/`)
-      .replace(/^\/cygdrive\/([a-zA-Z])(?:\/|$)/, (_, drive) => `${drive.toUpperCase()}:/`)
-      .replace(/^\/mnt\/([a-zA-Z])(?:\/|$)/, (_, drive) => `${drive.toUpperCase()}:/`)
-  }
-
-  export function overlaps(a: string, b: string) {
-    const relA = relative(a, b)
-    const relB = relative(b, a)
-    return !relA || !relA.startsWith("..") || !relB || !relB.startsWith("..")
-  }
-
-  export function contains(parent: string, child: string) {
-    return !relative(parent, child).startsWith("..")
+    return LocalFilesystem.mimeType(p)
   }
 }
diff --git a/packages/opencode/src/id/id.ts b/packages/opencode/src/id/id.ts
index 6673297cbfac..1a41a2629ee1 100644
--- a/packages/opencode/src/id/id.ts
+++ b/packages/opencode/src/id/id.ts
@@ -2,7 +2,7 @@ import z from "zod"
 import { randomBytes } from "crypto"
 
 export namespace Identifier {
-  const prefixes = {
+  export const prefixes = {
     session: "ses",
     message: "msg",
     permission: "per",
@@ -14,8 +14,43 @@ export namespace Identifier {
     workspace: "wrk",
   } as const
 
-  export function schema(prefix: keyof typeof prefixes) {
-    return z.string().startsWith(prefixes[prefix])
+  export type Prefix = keyof typeof prefixes
+
+  function label(prefix: Prefix) {
+    return `${prefix} id`
+  }
+
+  function issue(prefix: Prefix, input: string) {
+    if (!input) return `Expected ${label(prefix)}, received empty string`
+    if (!input.startsWith(prefixes[prefix])) {
+      return `Expected ${label(prefix)} starting with "${prefixes[prefix]}", received "${input}"`
+    }
+  }
+
+  export function is(prefix: Prefix, input: string): boolean {
+    return !issue(prefix, input)
+  }
+
+  export function assert(prefix: Prefix, input: string): asserts input is string {
+    const err = issue(prefix, input)
+    if (err) throw new TypeError(err)
+  }
+
+  export function parse(prefix: Prefix, input: string): string {
+    assert(prefix, input)
+    return input
+  }
+
+  export function schema<T extends string>(prefix: Prefix) {
+    return z.string().transform((input, ctx) => {
+      const err = issue(prefix, input)
+      if (!err) return input as T
+      ctx.addIssue({
+        code: z.ZodIssueCode.custom,
+        message: err,
+      })
+      return z.NEVER
+    })
   }
 
   const LENGTH = 26
@@ -24,23 +59,17 @@ export namespace Identifier {
   let lastTimestamp = 0
   let counter = 0
 
-  export function ascending(prefix: keyof typeof prefixes, given?: string) {
+  export function ascending(prefix: Prefix, given?: string) {
     return generateID(prefix, false, given)
   }
 
-  export function descending(prefix: keyof typeof prefixes, given?: string) {
+  export function descending(prefix: Prefix, given?: string) {
     return generateID(prefix, true, given)
   }
 
-  function generateID(prefix: keyof typeof prefixes, descending: boolean, given?: string): string {
-    if (!given) {
-      return create(prefix, descending)
-    }
-
-    if (!given.startsWith(prefixes[prefix])) {
-      throw new Error(`ID ${given} does not start with ${prefixes[prefix]}`)
-    }
-    return given
+  function generateID(prefix: Prefix, descending: boolean, given?: string): string {
+    if (!given) return create(prefix, descending)
+    return parse(prefix, given)
   }
 
   function randomBase62(length: number): string {
@@ -53,7 +82,7 @@ export namespace Identifier {
     return result
   }
 
-  export function create(prefix: keyof typeof prefixes, descending: boolean, timestamp?: number): string {
+  export function create(prefix: Prefix, descending: boolean, timestamp?: number): string {
     const currentTimestamp = timestamp ?? Date.now()
 
     if (currentTimestamp !== lastTimestamp) {
diff --git a/packages/opencode/src/index.ts b/packages/opencode/src/index.ts
index b3d1db7eb0cb..1058b9d8f87b 100644
--- a/packages/opencode/src/index.ts
+++ b/packages/opencode/src/index.ts
@@ -34,6 +34,7 @@ import path from "path"
 import { Global } from "./global"
 import { JsonMigration } from "./storage/json-migration"
 import { Database } from "./storage/db"
+import { PathMigration } from "./path/migrate"
 
 process.on("unhandledRejection", (e) => {
   Log.Default.error("rejection", {
@@ -120,6 +121,8 @@ let cli = yargs(hideBin(process.argv))
       }
       process.stderr.write("Database migration complete." + EOL)
     }
+
+    await PathMigration.run()
   })
   .usage("\n" + UI.logo())
   .completion("completion", "generate shell completion script")
diff --git a/packages/opencode/src/lsp/client.ts b/packages/opencode/src/lsp/client.ts
index de0c4386268a..c0c174a3d12b 100644
--- a/packages/opencode/src/lsp/client.ts
+++ b/packages/opencode/src/lsp/client.ts
@@ -1,7 +1,8 @@
 import { BusEvent } from "@/bus/bus-event"
 import { Bus } from "@/bus"
+import { Path } from "@/path/path"
+import type { FileURI, PathKey, PrettyPath } from "@/path/schema"
 import path from "path"
-import { pathToFileURL, fileURLToPath } from "url"
 import { createMessageConnection, StreamMessageReader, StreamMessageWriter } from "vscode-jsonrpc/node"
 import type { Diagnostic as VSCodeDiagnostic } from "vscode-languageserver-types"
 import { Log } from "../util/log"
@@ -11,7 +12,6 @@ import z from "zod"
 import type { LSPServer } from "./server"
 import { NamedError } from "@opencode-ai/util/error"
 import { withTimeout } from "../util/timeout"
-import { Instance } from "../project/instance"
 import { Filesystem } from "../util/filesystem"
 
 const DIAGNOSTICS_DEBOUNCE_MS = 150
@@ -19,6 +19,16 @@ const DIAGNOSTICS_DEBOUNCE_MS = 150
 export namespace LSPClient {
   const log = Log.create({ service: "lsp.client" })
 
+  type Entry = {
+    path: PrettyPath
+    diagnostics: Diagnostic[]
+  }
+
+  type Open = {
+    path: PrettyPath
+    version: number
+  }
+
   export type Info = NonNullable<Awaited<ReturnType<typeof create>>>
 
   export type Diagnostic = VSCodeDiagnostic
@@ -36,30 +46,34 @@ export namespace LSPClient {
       z.object({
         serverID: z.string(),
         path: z.string(),
+        pathKey: z.string(),
       }),
     ),
   }
 
-  export async function create(input: { serverID: string; server: LSPServer.Handle; root: string }) {
+  export async function create(input: { serverID: string; server: LSPServer.Handle; root: PrettyPath }) {
     const l = log.clone().tag("serverID", input.serverID)
     l.info("starting client")
+    const root = input.root
 
     const connection = createMessageConnection(
       new StreamMessageReader(input.server.process.stdout as any),
       new StreamMessageWriter(input.server.process.stdin as any),
     )
 
-    const diagnostics = new Map<string, Diagnostic[]>()
+    const diagnostics = new Map<PathKey, Entry>()
     connection.onNotification("textDocument/publishDiagnostics", (params) => {
-      const filePath = Filesystem.normalizePath(fileURLToPath(params.uri))
+      const path = Path.fromURI(params.uri)
+      const pathKey = Path.key(path)
+      const filePath = diagnostics.get(pathKey)?.path ?? files.get(pathKey)?.path ?? path
       l.info("textDocument/publishDiagnostics", {
         path: filePath,
         count: params.diagnostics.length,
       })
-      const exists = diagnostics.has(filePath)
-      diagnostics.set(filePath, params.diagnostics)
+      const exists = diagnostics.has(pathKey)
+      diagnostics.set(pathKey, { path: filePath, diagnostics: params.diagnostics })
       if (!exists && input.serverID === "typescript") return
-      Bus.publish(Event.Diagnostics, { path: filePath, serverID: input.serverID })
+      Bus.publish(Event.Diagnostics, { path: filePath, pathKey, serverID: input.serverID })
     })
     connection.onRequest("window/workDoneProgress/create", (params) => {
       l.info("window/workDoneProgress/create", params)
@@ -74,7 +88,7 @@ export namespace LSPClient {
     connection.onRequest("workspace/workspaceFolders", async () => [
       {
         name: "workspace",
-        uri: pathToFileURL(input.root).href,
+        uri: String(Path.uri(root)),
       },
     ])
     connection.listen()
@@ -82,12 +96,12 @@ export namespace LSPClient {
     l.info("sending initialize")
     await withTimeout(
       connection.sendRequest("initialize", {
-        rootUri: pathToFileURL(input.root).href,
+        rootUri: String(Path.uri(root)),
         processId: input.server.process.pid,
         workspaceFolders: [
           {
             name: "workspace",
-            uri: pathToFileURL(input.root).href,
+            uri: String(Path.uri(root)),
           },
         ],
         initializationOptions: {
@@ -133,12 +147,11 @@ export namespace LSPClient {
       })
     }
 
-    const files: {
-      [path: string]: number
-    } = {}
+    const files = new Map<PathKey, Open>()
 
     const result = {
-      root: input.root,
+      root,
+      rootKey: Path.key(root),
       get serverID() {
         return input.serverID
       },
@@ -146,33 +159,36 @@ export namespace LSPClient {
         return connection
       },
       notify: {
-        async open(input: { path: string }) {
-          input.path = path.isAbsolute(input.path) ? input.path : path.resolve(Instance.directory, input.path)
-          const text = await Filesystem.readText(input.path)
-          const extension = path.extname(input.path)
+        async open(input: { path: PrettyPath }) {
+          const file = input.path
+          const pathKey = Path.key(file)
+          const doc = files.get(pathKey)
+          const text = await Filesystem.readText(file)
+          const extension = path.extname(file)
           const languageId = LANGUAGE_EXTENSIONS[extension] ?? "plaintext"
+          const open = doc?.path ?? file
+          const uri: FileURI = Path.uri(open)
 
-          const version = files[input.path]
-          if (version !== undefined) {
-            log.info("workspace/didChangeWatchedFiles", input)
+          if (doc) {
+            log.info("workspace/didChangeWatchedFiles", { path: open })
             await connection.sendNotification("workspace/didChangeWatchedFiles", {
               changes: [
                 {
-                  uri: pathToFileURL(input.path).href,
+                  uri,
                   type: 2, // Changed
                 },
               ],
             })
 
-            const next = version + 1
-            files[input.path] = next
+            const next = doc.version + 1
+            files.set(pathKey, { path: open, version: next })
             log.info("textDocument/didChange", {
-              path: input.path,
+              path: open,
               version: next,
             })
             await connection.sendNotification("textDocument/didChange", {
               textDocument: {
-                uri: pathToFileURL(input.path).href,
+                uri,
                 version: next,
               },
               contentChanges: [{ text }],
@@ -180,48 +196,47 @@ export namespace LSPClient {
             return
           }
 
-          log.info("workspace/didChangeWatchedFiles", input)
+          log.info("workspace/didChangeWatchedFiles", { path: open })
           await connection.sendNotification("workspace/didChangeWatchedFiles", {
             changes: [
               {
-                uri: pathToFileURL(input.path).href,
+                uri,
                 type: 1, // Created
               },
             ],
           })
 
-          log.info("textDocument/didOpen", input)
-          diagnostics.delete(input.path)
+          log.info("textDocument/didOpen", { path: open })
+          diagnostics.delete(pathKey)
           await connection.sendNotification("textDocument/didOpen", {
             textDocument: {
-              uri: pathToFileURL(input.path).href,
+              uri,
               languageId,
               version: 0,
               text,
             },
           })
-          files[input.path] = 0
+          files.set(pathKey, { path: open, version: 0 })
           return
         },
       },
       get diagnostics() {
-        return diagnostics
+        return new Map([...diagnostics.values()].map((item) => [String(item.path), item.diagnostics]))
       },
-      async waitForDiagnostics(input: { path: string }) {
-        const normalizedPath = Filesystem.normalizePath(
-          path.isAbsolute(input.path) ? input.path : path.resolve(Instance.directory, input.path),
-        )
-        log.info("waiting for diagnostics", { path: normalizedPath })
+       async waitForDiagnostics(input: { path: PrettyPath }) {
+         const path = input.path
+         const pathKey = Path.key(path)
+        log.info("waiting for diagnostics", { path })
         let unsub: () => void
         let debounceTimer: ReturnType<typeof setTimeout> | undefined
         return await withTimeout(
           new Promise<void>((resolve) => {
             unsub = Bus.subscribe(Event.Diagnostics, (event) => {
-              if (event.properties.path === normalizedPath && event.properties.serverID === result.serverID) {
+              if (event.properties.pathKey === pathKey && event.properties.serverID === result.serverID) {
                 // Debounce to allow LSP to send follow-up diagnostics (e.g., semantic after syntax)
                 if (debounceTimer) clearTimeout(debounceTimer)
                 debounceTimer = setTimeout(() => {
-                  log.info("got diagnostics", { path: normalizedPath })
+                  log.info("got diagnostics", { path })
                   unsub?.()
                   resolve()
                 }, DIAGNOSTICS_DEBOUNCE_MS)
diff --git a/packages/opencode/src/lsp/index.ts b/packages/opencode/src/lsp/index.ts
index 2eb1ad93e986..0aad9dd22d9e 100644
--- a/packages/opencode/src/lsp/index.ts
+++ b/packages/opencode/src/lsp/index.ts
@@ -1,9 +1,10 @@
 import { BusEvent } from "@/bus/bus-event"
 import { Bus } from "@/bus"
+import { Path } from "@/path/path"
+import type { PathKey, PrettyPath } from "@/path/schema"
 import { Log } from "../util/log"
 import { LSPClient } from "./client"
 import path from "path"
-import { pathToFileURL, fileURLToPath } from "url"
 import { LSPServer } from "./server"
 import z from "zod"
 import { Config } from "../config/config"
@@ -15,6 +16,18 @@ import { spawn as lspspawn } from "./launch"
 export namespace LSP {
   const log = Log.create({ service: "lsp" })
 
+  function pretty(input: string): PrettyPath {
+    return Path.pretty(input, { cwd: Instance.directory })
+  }
+
+  function uri(input: PrettyPath) {
+    return Path.uri(input)
+  }
+
+  function key(serverID: string, root: PrettyPath) {
+    return `${serverID}:${Path.key(root)}`
+  }
+
   export const Event = {
     Updated: BusEvent.define("lsp.updated", z.object({})),
   }
@@ -175,12 +188,12 @@ export namespace LSP {
     })
   }
 
-  async function getClients(file: string) {
+  async function getClients(file: PrettyPath) {
     const s = await state()
     const extension = path.parse(file).ext || file
     const result: LSPClient.Info[] = []
 
-    async function schedule(server: LSPServer.Info, root: string, key: string) {
+    async function schedule(server: LSPServer.Info, root: PrettyPath, key: string) {
       const handle = await server
         .spawn(root)
         .then((value) => {
@@ -211,7 +224,7 @@ export namespace LSP {
         return undefined
       }
 
-      const existing = s.clients.find((x) => x.root === root && x.serverID === server.id)
+      const existing = s.clients.find((x) => x.rootKey === client.rootKey && x.serverID === server.id)
       if (existing) {
         await Process.stop(handle.process)
         return existing
@@ -226,15 +239,17 @@ export namespace LSP {
 
       const root = await server.root(file)
       if (!root) continue
-      if (s.broken.has(root + server.id)) continue
+      const id = key(server.id, root)
+      if (s.broken.has(id)) continue
 
-      const match = s.clients.find((x) => x.root === root && x.serverID === server.id)
+      const rootKey = Path.key(root)
+      const match = s.clients.find((x) => x.rootKey === rootKey && x.serverID === server.id)
       if (match) {
         result.push(match)
         continue
       }
 
-      const inflight = s.spawning.get(root + server.id)
+      const inflight = s.spawning.get(id)
       if (inflight) {
         const client = await inflight
         if (!client) continue
@@ -242,12 +257,12 @@ export namespace LSP {
         continue
       }
 
-      const task = schedule(server, root, root + server.id)
-      s.spawning.set(root + server.id, task)
+      const task = schedule(server, root, id)
+      s.spawning.set(id, task)
 
       task.finally(() => {
-        if (s.spawning.get(root + server.id) === task) {
-          s.spawning.delete(root + server.id)
+        if (s.spawning.get(id) === task) {
+          s.spawning.delete(id)
         }
       })
 
@@ -262,50 +277,64 @@ export namespace LSP {
   }
 
   export async function hasClients(file: string) {
+    const filePath = pretty(file)
     const s = await state()
-    const extension = path.parse(file).ext || file
+    const extension = path.parse(filePath).ext || filePath
     for (const server of Object.values(s.servers)) {
       if (server.extensions.length && !server.extensions.includes(extension)) continue
-      const root = await server.root(file)
+      const root = await server.root(filePath)
       if (!root) continue
-      if (s.broken.has(root + server.id)) continue
+      if (s.broken.has(key(server.id, root))) continue
       return true
     }
     return false
   }
 
   export async function touchFile(input: string, waitForDiagnostics?: boolean) {
-    log.info("touching file", { file: input })
-    const clients = await getClients(input)
+    const file = pretty(input)
+    log.info("touching file", { file })
+    const clients = await getClients(file)
     await Promise.all(
       clients.map(async (client) => {
-        const wait = waitForDiagnostics ? client.waitForDiagnostics({ path: input }) : Promise.resolve()
-        await client.notify.open({ path: input })
+        const wait = waitForDiagnostics ? client.waitForDiagnostics({ path: file }) : Promise.resolve()
+        await client.notify.open({ path: file })
         return wait
       }),
     ).catch((err) => {
-      log.error("failed to touch file", { err, file: input })
+      log.error("failed to touch file", { err, file })
     })
   }
 
   export async function diagnostics() {
-    const results: Record<string, LSPClient.Diagnostic[]> = {}
+    const results = new Map<PathKey, { path: PrettyPath; diagnostics: LSPClient.Diagnostic[] }>()
     for (const result of await runAll(async (client) => client.diagnostics)) {
       for (const [path, diagnostics] of result.entries()) {
-        const arr = results[path] || []
-        arr.push(...diagnostics)
-        results[path] = arr
+        const key = Path.key(path)
+        const item = results.get(key)
+        if (!item) {
+          results.set(key, { path: Path.pretty(path), diagnostics: [...diagnostics] })
+          continue
+        }
+        item.diagnostics.push(...diagnostics)
       }
     }
-    return results
+    return Object.fromEntries([...results.values()].map((item) => [item.path, item.diagnostics]))
+  }
+
+  export function diagnosticsFor(file: PrettyPath, input: Record<string, LSPClient.Diagnostic[]>) {
+    const value = Path.key(file)
+    for (const [path, diagnostics] of Object.entries(input)) {
+      if (Path.match(path, value)) return { path, diagnostics }
+    }
   }
 
   export async function hover(input: { file: string; line: number; character: number }) {
-    return run(input.file, (client) => {
+    const file = pretty(input.file)
+    return run(file, (client) => {
       return client.connection
         .sendRequest("textDocument/hover", {
           textDocument: {
-            uri: pathToFileURL(input.file).href,
+            uri: uri(file),
           },
           position: {
             line: input.line,
@@ -369,7 +398,7 @@ export namespace LSP {
   }
 
   export async function documentSymbol(uri: string) {
-    const file = fileURLToPath(uri)
+    const file = Path.fromURI(uri)
     return run(file, (client) =>
       client.connection
         .sendRequest("textDocument/documentSymbol", {
@@ -384,10 +413,11 @@ export namespace LSP {
   }
 
   export async function definition(input: { file: string; line: number; character: number }) {
-    return run(input.file, (client) =>
+    const file = pretty(input.file)
+    return run(file, (client) =>
       client.connection
         .sendRequest("textDocument/definition", {
-          textDocument: { uri: pathToFileURL(input.file).href },
+          textDocument: { uri: uri(file) },
           position: { line: input.line, character: input.character },
         })
         .catch(() => null),
@@ -395,10 +425,11 @@ export namespace LSP {
   }
 
   export async function references(input: { file: string; line: number; character: number }) {
-    return run(input.file, (client) =>
+    const file = pretty(input.file)
+    return run(file, (client) =>
       client.connection
         .sendRequest("textDocument/references", {
-          textDocument: { uri: pathToFileURL(input.file).href },
+          textDocument: { uri: uri(file) },
           position: { line: input.line, character: input.character },
           context: { includeDeclaration: true },
         })
@@ -407,10 +438,11 @@ export namespace LSP {
   }
 
   export async function implementation(input: { file: string; line: number; character: number }) {
-    return run(input.file, (client) =>
+    const file = pretty(input.file)
+    return run(file, (client) =>
       client.connection
         .sendRequest("textDocument/implementation", {
-          textDocument: { uri: pathToFileURL(input.file).href },
+          textDocument: { uri: uri(file) },
           position: { line: input.line, character: input.character },
         })
         .catch(() => null),
@@ -418,10 +450,11 @@ export namespace LSP {
   }
 
   export async function prepareCallHierarchy(input: { file: string; line: number; character: number }) {
-    return run(input.file, (client) =>
+    const file = pretty(input.file)
+    return run(file, (client) =>
       client.connection
         .sendRequest("textDocument/prepareCallHierarchy", {
-          textDocument: { uri: pathToFileURL(input.file).href },
+          textDocument: { uri: uri(file) },
           position: { line: input.line, character: input.character },
         })
         .catch(() => []),
@@ -429,10 +462,11 @@ export namespace LSP {
   }
 
   export async function incomingCalls(input: { file: string; line: number; character: number }) {
-    return run(input.file, async (client) => {
+    const file = pretty(input.file)
+    return run(file, async (client) => {
       const items = (await client.connection
         .sendRequest("textDocument/prepareCallHierarchy", {
-          textDocument: { uri: pathToFileURL(input.file).href },
+          textDocument: { uri: uri(file) },
           position: { line: input.line, character: input.character },
         })
         .catch(() => [])) as any[]
@@ -442,10 +476,11 @@ export namespace LSP {
   }
 
   export async function outgoingCalls(input: { file: string; line: number; character: number }) {
-    return run(input.file, async (client) => {
+    const file = pretty(input.file)
+    return run(file, async (client) => {
       const items = (await client.connection
         .sendRequest("textDocument/prepareCallHierarchy", {
-          textDocument: { uri: pathToFileURL(input.file).href },
+          textDocument: { uri: uri(file) },
           position: { line: input.line, character: input.character },
         })
         .catch(() => [])) as any[]
@@ -460,7 +495,7 @@ export namespace LSP {
     return Promise.all(tasks)
   }
 
-  async function run<T>(file: string, input: (client: LSPClient.Info) => Promise<T>): Promise<T[]> {
+  async function run<T>(file: PrettyPath, input: (client: LSPClient.Info) => Promise<T>): Promise<T[]> {
     const clients = await getClients(file)
     const tasks = clients.map((x) => input(x))
     return Promise.all(tasks)
diff --git a/packages/opencode/src/lsp/server.ts b/packages/opencode/src/lsp/server.ts
index 123e8aea8601..6530f3a68676 100644
--- a/packages/opencode/src/lsp/server.ts
+++ b/packages/opencode/src/lsp/server.ts
@@ -13,6 +13,8 @@ import { Archive } from "../util/archive"
 import { Process } from "../util/process"
 import { which } from "../util/which"
 import { Module } from "@opencode-ai/util/module"
+import { Path } from "../path/path"
+import type { PrettyPath } from "../path/schema"
 import { spawn } from "./launch"
 
 export namespace LSPServer {
@@ -30,29 +32,24 @@ export namespace LSPServer {
     initialization?: Record<string, any>
   }
 
-  type RootFunction = (file: string) => Promise<string | undefined>
+  type RootFunction = (file: PrettyPath) => Promise<PrettyPath | undefined>
+
+  const firstUp = async (targets: string[], start: PrettyPath, stop?: PrettyPath) => {
+    const files = Filesystem.up({ targets, start, stop })
+    const first = await files.next()
+    await files.return()
+    return first.value
+  }
 
   const NearestRoot = (includePatterns: string[], excludePatterns?: string[]): RootFunction => {
     return async (file) => {
-      if (excludePatterns) {
-        const excludedFiles = Filesystem.up({
-          targets: excludePatterns,
-          start: path.dirname(file),
-          stop: Instance.directory,
-        })
-        const excluded = await excludedFiles.next()
-        await excludedFiles.return()
-        if (excluded.value) return undefined
-      }
-      const files = Filesystem.up({
-        targets: includePatterns,
-        start: path.dirname(file),
-        stop: Instance.directory,
-      })
-      const first = await files.next()
-      await files.return()
-      if (!first.value) return Instance.directory
-      return path.dirname(first.value)
+      const start = Path.parent(file)
+      const stop = Instance.directory
+
+      if (excludePatterns && (await firstUp(excludePatterns, start, stop))) return undefined
+
+      const root = await firstUp(includePatterns, start, stop)
+      return root ? Path.parent(root) : stop
     }
   }
 
@@ -67,15 +64,9 @@ export namespace LSPServer {
   export const Deno: Info = {
     id: "deno",
     root: async (file) => {
-      const files = Filesystem.up({
-        targets: ["deno.json", "deno.jsonc"],
-        start: path.dirname(file),
-        stop: Instance.directory,
-      })
-      const first = await files.next()
-      await files.return()
-      if (!first.value) return undefined
-      return path.dirname(first.value)
+      const root = await firstUp(["deno.json", "deno.jsonc"], Path.parent(file), Instance.directory)
+      if (!root) return undefined
+      return Path.parent(root)
     },
     extensions: [".ts", ".tsx", ".js", ".jsx", ".mjs"],
     async spawn(root) {
@@ -851,31 +842,21 @@ export namespace LSPServer {
 
   export const RustAnalyzer: Info = {
     id: "rust",
-    root: async (root) => {
-      const crateRoot = await NearestRoot(["Cargo.toml", "Cargo.lock"])(root)
-      if (crateRoot === undefined) {
-        return undefined
-      }
-      let currentDir = crateRoot
+    root: async (file) => {
+      const root = await firstUp(["Cargo.toml", "Cargo.lock"], Path.parent(file))
+      const crateRoot = root ? Path.parent(root) : Instance.directory
+      const worktree = Instance.worktree === "/" ? undefined : Path.truecaseSync(Instance.worktree)
 
-      while (currentDir !== path.dirname(currentDir)) {
-        // Stop at filesystem root
-        const cargoTomlPath = path.join(currentDir, "Cargo.toml")
+      for (const dir of Path.up(crateRoot, { stop: worktree })) {
+        const cargoTomlPath = Path.join(dir, "Cargo.toml")
         try {
           const cargoTomlContent = await Filesystem.readText(cargoTomlPath)
           if (cargoTomlContent.includes("[workspace]")) {
-            return currentDir
+            return dir
           }
         } catch (err) {
           // File doesn't exist or can't be read, continue searching up
         }
-
-        const parentDir = path.dirname(currentDir)
-        if (parentDir === currentDir) break // Reached filesystem root
-        currentDir = parentDir
-
-        // Stop if we've gone above the app root
-        if (!currentDir.startsWith(Instance.worktree)) break
       }
 
       return crateRoot
diff --git a/packages/opencode/src/path/migrate.ts b/packages/opencode/src/path/migrate.ts
new file mode 100644
index 000000000000..8cbaed9c7bf6
--- /dev/null
+++ b/packages/opencode/src/path/migrate.ts
@@ -0,0 +1,145 @@
+import path from "path"
+import { ProjectTable } from "@/project/project.sql"
+import { Path } from "@/path/path"
+import type { PrettyPath } from "@/path/schema"
+import { Global } from "@/global"
+import { Database, eq } from "@/storage/db"
+import { Filesystem } from "@/util/filesystem"
+import { Log } from "@/util/log"
+import { SessionTable } from "@/session/session.sql"
+import { WorkspaceTable } from "@/control-plane/workspace.sql"
+
+export namespace PathMigration {
+  const VERSION = 1
+  const log = Log.create({ service: "path-migration" })
+
+  type Opts = {
+    force?: boolean
+    marker?: string
+  }
+
+  type Marker = {
+    version: number
+    db: string
+    sig: string
+    time: number
+  }
+
+  export type Result = {
+    skipped: boolean
+    marker: string
+    change: {
+      project: number
+      session: number
+      workspace: number
+    }
+  }
+
+  const stored = Path.truecaseSync
+
+  function same(a: string[], b: string[]) {
+    return a.length === b.length && a.every((item, idx) => item === b[idx])
+  }
+
+  function uniq(list: string[], worktree?: string) {
+    const seen = new Set<string>()
+    const out: PrettyPath[] = []
+    for (const item of list) {
+      const dir = stored(item)
+      if (dir && worktree && Path.eq(dir, worktree)) continue
+      const id = Path.key(dir)
+      if (seen.has(id)) continue
+      seen.add(id)
+      out.push(dir)
+    }
+    return out
+  }
+
+  function sig() {
+    const stat = Filesystem.stat(Database.Path)
+    if (!stat) return ""
+    const ino = typeof stat.ino === "bigint" ? Number(stat.ino) : stat.ino
+    const birth = typeof stat.birthtimeMs === "bigint" ? Number(stat.birthtimeMs) : stat.birthtimeMs
+    return `${ino ?? 0}:${birth ?? 0}`
+  }
+
+  export function marker() {
+    return path.join(Global.Path.data, "migration", "path", `${path.basename(Database.Path)}-v${VERSION}.json`)
+  }
+
+  async function done(file: string, force?: boolean) {
+    if (force || process.env.OPENCODE_FORCE_PATH_MIGRATION === "1") return false
+    const mark = await Filesystem.readJson<Marker>(file).catch(() => undefined)
+    if (!mark) return false
+    const db = sig()
+    if (!db || mark.sig !== db) return false
+    return mark.version === VERSION && mark.db === Database.Path
+  }
+
+  async function write(file: string) {
+    await Filesystem.writeJson(file, {
+      version: VERSION,
+      db: Database.Path,
+      sig: sig(),
+      time: Date.now(),
+    } satisfies Marker)
+  }
+
+  export async function run(opts: Opts = {}): Promise<Result> {
+    const file = opts.marker ?? marker()
+    if (await done(file, opts.force)) {
+      return {
+        skipped: true,
+        marker: file,
+        change: {
+          project: 0,
+          session: 0,
+          workspace: 0,
+        },
+      }
+    }
+
+    const change = Database.transaction((db) => {
+      const change = {
+        project: 0,
+        session: 0,
+        workspace: 0,
+      }
+
+      for (const row of db.select().from(ProjectTable).all()) {
+        const worktree = stored(row.worktree)
+        const sandboxes = uniq(row.sandboxes, worktree)
+        if (worktree === row.worktree && same(sandboxes, row.sandboxes)) continue
+        db.update(ProjectTable).set({ worktree, sandboxes }).where(eq(ProjectTable.id, row.id)).run()
+        change.project++
+      }
+
+      for (const row of db.select().from(SessionTable).all()) {
+        const directory = stored(row.directory)
+        if (directory === row.directory) continue
+        db.update(SessionTable).set({ directory }).where(eq(SessionTable.id, row.id)).run()
+        change.session++
+      }
+
+      for (const row of db.select().from(WorkspaceTable).all()) {
+        const directory = row.directory ? stored(row.directory) : null
+        if (directory === row.directory) continue
+        db.update(WorkspaceTable).set({ directory }).where(eq(WorkspaceTable.id, row.id)).run()
+        change.workspace++
+      }
+
+      return change
+    })
+
+    await write(file)
+    log.info("completed", {
+      marker: file,
+      ...change,
+    })
+    return {
+      skipped: false,
+      marker: file,
+      change,
+    }
+  }
+}
diff --git a/packages/opencode/src/path/path.ts b/packages/opencode/src/path/path.ts
new file mode 100644
index 000000000000..33062ce500ff
--- /dev/null
+++ b/packages/opencode/src/path/path.ts
@@ -0,0 +1,583 @@
+import { readdirSync } from "fs"
+import { readdir, realpath } from "fs/promises"
+import os from "os"
+import path from "path"
+
+import { FileURI, PathKey, PosixPath, PrettyPath, RelativePath, RepoPath } from "./schema"
+
+type OS = "windows" | "macos" | "linux"
+type Platform = NodeJS.Platform | OS
+
+type Opts = {
+  cwd?: string
+  platform?: Platform
+}
+
+type HomeOpts = {
+  home?: string
+  platform?: Platform
+}
+
+type DisplayOpts = Opts & {
+  home?: string | false
+  relative?: boolean
+}
+
+type ParseOpts = Opts & {
+  encoded?: boolean
+  label?: string
+}
+
+type UpOpts = Opts & {
+  stop?: string
+}
+
+/**
+ * Path exposes a few intentionally different string forms instead of one
+ * "normalized" answer.
+ *
+ * - `pretty` is the main absolute, native-separator form used inside the app.
+ * - `key` is the same path folded for equality and map/set lookups.
+ * - `canonical` keeps repo and protocol-facing values stable by using POSIX form
+ *   for Windows absolute paths while leaving relative inputs alone.
+ * - `physical` asks the filesystem for the real on-disk path and best-effort
+ *   casing, even when some trailing segments do not exist yet.
+ *
+ * Windows support also accepts common drive aliases like `/c/...`,
+ * `/cygdrive/c/...`, `/mnt/c/...`, plus `file://` URIs, so callers can feed in
+ * editor, shell, and URI-derived values without pre-normalizing them first.
+ */
+
+type Lib = typeof path.posix
+
+function platformText(input?: Platform) {
+  if (!input) return process.platform
+  if (input === "windows") return "win32"
+  if (input === "macos") return "darwin"
+  if (input === "linux") return "linux"
+  return input
+}
+
+function pf(opts?: { platform?: Platform }) {
+  return platformText(opts?.platform)
+}
+
+function lib(platform: NodeJS.Platform): Lib {
+  return platform === "win32" ? path.win32 : path.posix
+}
+
+function home(opts: HomeOpts = {}) {
+  return opts.home ?? process.env.OPENCODE_TEST_HOME ?? os.homedir()
+}
+
+function fixDrive(input: string) {
+  return input.replace(/^[a-z]:/, (match) => match.toUpperCase())
+}
+
+function clean(input: string, platform: NodeJS.Platform) {
+  const text = lib(platform).normalize(input)
+  if (platform !== "win32") return text
+  return fixDrive(text).replaceAll("/", "\\")
+}
+
+function sentinel(input: string) {
+  return input === "/"
+}
+
+function raw(input: string, platform: NodeJS.Platform) {
+  if (input.startsWith("file://")) return fromURIText(input, platform)
+  if (platform !== "win32") return input
+  return input
+    .replace(/^\/([a-zA-Z]):(?:[\\/]|$)/, (_, drive) => `${drive.toUpperCase()}:\\`)
+    .replace(/^\/([a-zA-Z])(?:[\\/]|$)/, (_, drive) => `${drive.toUpperCase()}:\\`)
+    .replace(/^\/cygdrive\/([a-zA-Z])(?:[\\/]|$)/, (_, drive) => `${drive.toUpperCase()}:\\`)
+    .replace(/^\/mnt\/([a-zA-Z])(?:[\\/]|$)/, (_, drive) => `${drive.toUpperCase()}:\\`)
+}
+
+function absolute(input: string, platform: NodeJS.Platform) {
+  return lib(platform).isAbsolute(raw(input, platform))
+}
+
+function winabs(input: string) {
+  return (
+    input.startsWith("file://") ||
+    /^[\\/]{2}[^\\/]/.test(input) ||
+    /^[a-zA-Z]:(?:[\\/]|$)/.test(input) ||
+    /^\/([a-zA-Z]:|[a-zA-Z])(?:[\\/]|$)/.test(input) ||
+    /^\/cygdrive\/[a-zA-Z](?:[\\/]|$)/.test(input) ||
+    /^\/mnt\/[a-zA-Z](?:[\\/]|$)/.test(input)
+  )
+}
+
+function guessText(input: string): NodeJS.Platform | undefined {
+  if (input.startsWith("file://")) {
+    try {
+      const url = new URL(input)
+      const host = url.hostname.toLowerCase()
+      if (host && host !== "localhost") return "win32"
+      if (/^\/([A-Za-z]:|[A-Za-z])(?:[\/]|$)/.test(url.pathname)) return "win32"
+      if (/^\/(?:cygdrive|mnt)\/[A-Za-z](?:[\/]|$)/.test(url.pathname)) return "win32"
+      return "linux"
+    } catch {}
+  }
+  if (winabs(input)) return "win32"
+  if (input.startsWith("/")) return "linux"
+}
+
+function base(input: string, platform: NodeJS.Platform) {
+  const mod = lib(platform)
+  const text = raw(input, platform)
+  return clean(mod.isAbsolute(text) ? text : mod.resolve(text), platform)
+}
+
+function prettyText(input: string, opts: Opts = {}) {
+  const platform = pf(opts)
+  const mod = lib(platform)
+  const text = raw(input, platform)
+  const cwd = opts.cwd ? base(opts.cwd, platform) : undefined
+  return clean(cwd ? mod.resolve(cwd, text) : mod.resolve(text), platform)
+}
+
+function expandText(input: string, opts: HomeOpts = {}) {
+  const platform = pf(opts)
+  const mod = lib(platform)
+  const dir = home(opts)
+  if (input === "~" || input === "$HOME") return prettyText(dir, { platform })
+  if (input.startsWith(`~${mod.sep}`)) return prettyText(input.slice(2), { cwd: dir, platform })
+  if (input.startsWith(`$HOME${mod.sep}`)) return prettyText(input.slice(6), { cwd: dir, platform })
+  if (mod.sep !== "/") {
+    if (input.startsWith("~/")) return prettyText(input.slice(2), { cwd: dir, platform })
+    if (input.startsWith("$HOME/")) return prettyText(input.slice(6), { cwd: dir, platform })
+  }
+  return input
+}
+
+function inside(parent: string, child: string, platform: NodeJS.Platform) {
+  const mod = lib(platform)
+  const rel = mod.relative(parent, child)
+  if (!rel) return true
+  if (mod.isAbsolute(rel)) return false
+  return !rel.startsWith("..")
+}
+
+function displayText(input: string, opts: DisplayOpts = {}) {
+  const platform = pf(opts)
+  const mod = lib(platform)
+  const text = prettyText(input, opts)
+  if (opts.relative) {
+    const cwd = prettyText(opts.cwd ?? process.cwd(), { platform })
+    if (inside(cwd, text, platform)) return mod.relative(cwd, text) || "."
+  }
+  if (opts.home === false) return text
+  const root = opts.home
+  const dir = prettyText(home({ home: root, platform }), { platform })
+  if (!inside(dir, text, platform)) return text
+  if (text === dir) return "~"
+  return `~${mod.sep}${mod.relative(dir, text)}`
+}
+
+function encode(input: string) {
+  return encodeURIComponent(input)
+}
+
+function decode(input: string) {
+  try {
+    return decodeURIComponent(input)
+  } catch {
+    return input
+  }
+}
+
+function decodeText(input: string, label: string) {
+  try {
+    return decodeURIComponent(input)
+  } catch {
+    throw new TypeError(`Invalid percent-encoding in ${label}: ${input}`)
+  }
+}
+
+function ingressText(input: string, opts: Omit<ParseOpts, "encoded"> = {}) {
+  const label = opts.label ?? "path"
+  if (!input) throw new TypeError(`Expected ${label}, received empty string`)
+  if (input.includes("\0")) throw new TypeError(`Expected ${label} without null bytes`)
+
+  const platform = pf(opts)
+  if (absolute(input, platform)) return prettyText(input, opts)
+  if (!input.includes("%")) return prettyText(input, opts)
+
+  const text = decodeText(input, label)
+  if (absolute(text, platform)) return prettyText(text, opts)
+  return prettyText(input, opts)
+}
+
+function parseText(input: string, opts: ParseOpts = {}) {
+  const label = opts.label ?? "path"
+  if (!input) throw new TypeError(`Expected ${label}, received empty string`)
+  if (input.includes("\0")) throw new TypeError(`Expected ${label} without null bytes`)
+  const text = opts.encoded ? decodeText(input, label) : input
+  return prettyText(text, opts)
+}
+
+function stopText(input: string | undefined, platform: NodeJS.Platform) {
+  if (!input) return
+  if (sentinel(input)) return input
+  return prettyText(input, { platform })
+}
+
+function repoText(input: string) {
+  const dir = /[\\/]$/.test(input)
+  const text = path.posix.normalize(input.replaceAll("\\", "/") || ".").replace(/^(?:\.\/)+/, "")
+  if (text === ".") return "."
+  const clean = text.replace(/\/+$/, "")
+  return dir ? `${clean}/` : clean
+}
+
+function repoLeaf(input: string) {
+  const text = repoText(input).replace(/\/+$/, "")
+  if (text === ".") return "."
+  return path.posix.basename(text)
+}
+
+function repoParentText(input: string) {
+  const text = repoText(input).replace(/\/+$/, "")
+  if (text === ".") return "."
+  return repoText(path.posix.dirname(text) || ".")
+}
+
+function hiddenText(input: string) {
+  const parts = input.replaceAll("\\", "/").replace(/\/+$/, "").split("/")
+  return parts.some(
+    (part, idx) => (part.startsWith(".") && part.length > 1) || (part === "." && idx > 0 && idx === parts.length - 1),
+  )
+}
+
+function fromURIText(input: string, platform: NodeJS.Platform) {
+  const url = new URL(input)
+  if (url.protocol !== "file:") throw new TypeError(`Expected file URI: ${input}`)
+  const host = url.hostname.toLowerCase()
+  const text = decode(url.pathname)
+  const local = !host || host === "localhost"
+  if (platform !== "win32") {
+    return `${local ? "" : `//${url.host}`}${text}`
+  }
+  if (!local) {
+    return `\\\\${url.host}${text.replaceAll("/", "\\")}`
+  }
+  return fixDrive(text.replace(/^\/([a-zA-Z]:)/, "$1").replaceAll("/", "\\"))
+}
+
+function toURIText(input: string, platform: NodeJS.Platform) {
+  if (platform !== "win32") {
+    return `file://${input.split("/").map((part, idx) => (idx === 0 ? part : encode(part))).join("/")}`
+  }
+  if (input.startsWith("\\\\")) {
+    const parts = input.slice(2).split("\\")
+    const host = parts.shift() ?? ""
+    const body = parts.map(encode).join("/")
+    return `file://${host}/${body}`
+  }
+  const text = input.replaceAll("\\", "/")
+  const body = text
+    .slice(2)
+    .split("/")
+    .map((part, idx) => (idx === 0 ? part : encode(part)))
+    .join("/")
+  return `file:///${fixDrive(text.slice(0, 2))}${body}`
+}
+
+async function physicalAsync(input: string, opts: Opts = {}): Promise<PrettyPath> {
+  const platform = pf(opts)
+  const mod = lib(platform)
+  const text = prettyText(input, opts)
+  const hit = await realpath(text).catch(() => undefined)
+  if (hit) return PrettyPath.make(clean(hit, platform))
+
+  const parts: string[] = []
+  let dir = text
+
+  while (true) {
+    const parent = mod.dirname(dir)
+    if (parent === dir) return PrettyPath.make(text)
+    parts.unshift(mod.basename(dir))
+    const next = await realpath(parent).catch(() => undefined)
+    if (next) return PrettyPath.make(clean(mod.join(next, ...parts), platform))
+    dir = parent
+  }
+}
+
+function* upText(input: string, opts: UpOpts = {}) {
+  const platform = pf(opts)
+  const mod = lib(platform)
+  const stop = stopText(opts.stop, platform)
+  let dir = prettyText(input, opts)
+
+  if (stop && stop !== "/" && !inside(stop, dir, platform)) return
+
+  while (true) {
+    yield PrettyPath.make(dir)
+    if (stop && dir === stop) return
+    const parent = mod.dirname(dir)
+    if (parent === dir) return
+    dir = parent
+  }
+}
+
+export namespace Path {
+  export type Options = Opts
+
+  export function platform(input?: Platform) {
+    return platformText(input)
+  }
+
+  export function guess(input: string) {
+    return guessText(input)
+  }
+
+  export function isAbsolute(input: string, opts: Omit<Opts, "cwd"> = {}) {
+    return absolute(input, pf(opts))
+  }
+
+  /**
+   * Returns the absolute app-facing path form.
+   *
+   * This resolves relative input against `cwd`, expands accepted Windows drive
+   * aliases, and preserves the host platform's separator style.
+   */
+  export function pretty(input: string, opts: Opts = {}) {
+    return PrettyPath.make(prettyText(input, opts))
+  }
+
+  export function from(input: string, opts: ParseOpts = {}) {
+    return PrettyPath.make(parseText(input, opts))
+  }
+
+  /**
+   * Parses already-decoded boundary input like headers and query params.
+   *
+    * Absolute inputs are treated as raw native paths so literal `%` segments are
+    * preserved. Non-absolute inputs get one decode attempt so older encoded
+    * headers can still become absolute paths, and malformed encoded values fail
+    * clearly.
+   */
+  export function ingress(input: string, opts: Omit<ParseOpts, "encoded"> = {}) {
+    return PrettyPath.make(ingressText(input, opts))
+  }
+
+  /**
+   * Returns the lookup/equality form for a path.
+   *
+   * On Windows the key is lower-cased so path comparisons match the
+   * filesystem's case-insensitive behavior.
+   */
+  export function key(input: string, opts: Opts = {}) {
+    if (sentinel(input)) return PathKey.make(input)
+    const platform = pf(opts)
+    const text = pretty(input, opts)
+    if (platform !== "win32") return PathKey.make(text)
+    return PathKey.make(text.toLowerCase())
+  }
+
+  export function posix(input: string, opts: Opts = {}) {
+    return PosixPath.make(pretty(input, opts).replaceAll("\\", "/"))
+  }
+
+  /**
+   * Returns a stable serialized form.
+   *
+   * Windows absolute paths are rewritten to POSIX-style text so values can move
+   * across shells, config files, and URIs without backslash ambiguity. Relative
+   * paths are left unchanged because their meaning depends on the caller's base.
+   */
+  export function canonical(input: string, opts: Opts = {}) {
+    const platform = pf(opts)
+    if (platform !== "win32") return input
+    if (!winabs(input)) return input
+    return posix(input, opts)
+  }
+
+  export function expand(input: string, opts: HomeOpts = {}) {
+    return expandText(input, opts)
+  }
+
+  /**
+   * Returns a user-facing path string.
+   *
+   * This optionally collapses paths under home to `~` and can render paths
+   * relative to `cwd`, but it never changes the underlying filesystem target.
+   */
+  export function display(input: string, opts: DisplayOpts = {}) {
+    return displayText(input, opts)
+  }
+
+  export function join(dir: string, child: string, opts: Omit<Opts, "cwd"> = {}) {
+    return pretty(child, { ...opts, cwd: dir })
+  }
+
+  export function parent(input: string, opts: Omit<Opts, "cwd"> = {}) {
+    const platform = pf(opts)
+    return pretty(lib(platform).dirname(pretty(input, opts)), { platform })
+  }
+
+  export function rel(from: string, to: string, opts: Opts = {}) {
+    const platform = pf(opts)
+    const mod = lib(platform)
+    const text = mod.relative(pretty(from, opts), pretty(to, opts)) || "."
+    return RelativePath.make(text)
+  }
+
+  export function repoFrom(root: string, file: string, opts: Omit<Opts, "cwd"> = {}) {
+    return repo(rel(root, file, opts))
+  }
+
+  export function repo(input: string) {
+    return RepoPath.make(repoText(input))
+  }
+
+  export function repoParent(input: string) {
+    return RepoPath.make(repoParentText(input))
+  }
+
+  export function repoName(input: string) {
+    return repoLeaf(input)
+  }
+
+  export function repoDepth(input: string) {
+    const text = repoText(input).replace(/\/+$/, "")
+    if (text === ".") return 0
+    return text.split("/").filter(Boolean).length
+  }
+
+  export function repoIsDir(input: string) {
+    const text = repoText(input)
+    return text !== "." && text.endsWith("/")
+  }
+
+  export function hidden(input: string) {
+    return hiddenText(input)
+  }
+
+  /**
+   * Converts a path to a `file://` URI after first normalizing it with
+   * `pretty`, including UNC and Windows drive handling.
+   */
+  export function uri(input: string, opts: Opts = {}) {
+    return FileURI.make(toURIText(pretty(input, opts), pf(opts)))
+  }
+
+  /**
+   * Parses a `file://` URI into the same absolute native form returned by
+   * `pretty`, restoring UNC hosts and Windows drive letters when needed.
+   */
+  export function fromURI(input: string, opts: Omit<Opts, "cwd"> = {}) {
+    return PrettyPath.make(clean(fromURIText(input, pf(opts)), pf(opts)))
+  }
+
+  export function eq(a: string, b: string, opts: Opts = {}) {
+    return key(a, opts) === key(b, opts)
+  }
+
+  /**
+   * Checks directory containment after normalizing both inputs into the same
+   * platform rules. Relative and absolute paths never match each other.
+   */
+  export function contains(parent: string, child: string, opts: Opts = {}) {
+    const platform = pf(opts)
+    const mod = lib(platform)
+    const a = raw(parent, platform)
+    const b = raw(child, platform)
+    if (mod.isAbsolute(a) !== mod.isAbsolute(b)) return false
+    return inside(pretty(parent, opts), pretty(child, opts), platform)
+  }
+
+  export function overlaps(a: string, b: string, opts: Opts = {}) {
+    return contains(a, b, opts) || contains(b, a, opts)
+  }
+
+  /**
+   * Yields the starting directory and each parent up to `stop` or the
+   * filesystem root. When `stop` is provided, traversal is bounded to that
+   * ancestor and includes it.
+   */
+  export function up(input: string, opts: UpOpts = {}) {
+    return upText(input, opts)
+  }
+
+  export function externalGlob(dir: string, opts: Opts = {}) {
+    return `${posix(dir, opts).replace(/\/+$/, "")}/*`
+  }
+
+  export function match(input: string, value: PathKey, opts: Opts = {}) {
+    return key(input, opts) === value
+  }
+
+  export async function physicalKey(input: string, opts: Opts = {}) {
+    return key(await physicalAsync(input, opts), opts)
+  }
+
+  /**
+   * Rebuilds the path using the filesystem's recorded casing on Windows.
+   *
+   * Unlike `physical`, this does not resolve symlinks; it walks segments and
+   * keeps any missing tail as provided once the walk can no longer continue.
+   */
+  export async function truecase(input: string, opts: Omit<Opts, "cwd"> = {}) {
+    if (sentinel(input)) return PrettyPath.make(input)
+    const platform = pf(opts)
+    const text = pretty(input, opts)
+    if (platform !== "win32") return text
+
+    const mod = path.win32
+    const root = mod.parse(text).root
+    const rest = text.slice(root.length).split("\\").filter(Boolean)
+    let out = root
+
+    for (const [idx, seg] of rest.entries()) {
+      const list = await readdir(out).catch(() => undefined)
+      if (!list) return PrettyPath.make(clean(mod.join(out, ...rest.slice(idx)), platform))
+
+      const hit = list.find((item) => item.toLowerCase() === seg.toLowerCase())
+      if (!hit) return PrettyPath.make(clean(mod.join(out, ...rest.slice(idx)), platform))
+
+      out = mod.join(out, hit)
+    }
+
+    return PrettyPath.make(clean(out, platform))
+  }
+
+  export function truecaseSync(input: string, opts: Omit<Opts, "cwd"> = {}) {
+    if (sentinel(input)) return PrettyPath.make(input)
+    const platform = pf(opts)
+    const text = pretty(input, opts)
+    if (platform !== "win32") return text
+
+    const mod = path.win32
+    const root = mod.parse(text).root
+    const rest = text.slice(root.length).split("\\").filter(Boolean)
+    let out = root
+
+    for (const [idx, seg] of rest.entries()) {
+      let list: string[] | undefined
+      try {
+        list = readdirSync(out)
+      } catch {
+        return PrettyPath.make(clean(mod.join(out, ...rest.slice(idx)), platform))
+      }
+
+      const hit = list.find((item) => item.toLowerCase() === seg.toLowerCase())
+      if (!hit) return PrettyPath.make(clean(mod.join(out, ...rest.slice(idx)), platform))
+
+      out = mod.join(out, hit)
+    }
+
+    return PrettyPath.make(clean(out, platform))
+  }
+
+  /**
+   * Returns the best available on-disk path.
+   *
+   * This resolves symlinks via `realpath()` when possible, then falls back to
+   * resolving the deepest existing parent so callers still get a useful path for
+   * files or directories that are about to be created.
+   */
+  export const physical = physicalAsync
+}
diff --git a/packages/opencode/src/path/schema.ts b/packages/opencode/src/path/schema.ts
new file mode 100644
index 000000000000..cef89727206a
--- /dev/null
+++ b/packages/opencode/src/path/schema.ts
@@ -0,0 +1,173 @@
+import { Schema } from "effect"
+import path from "path"
+
+import { withStatics, zodString } from "@/util/schema"
+
+/**
+ * These brands document which path shape a string is expected to already be in.
+ * The `make` helpers are intentionally unsafe; normalization lives in
+ * `src/path/path.ts`, while the brands keep different path forms from being
+ * mixed up by accident.
+ */
+
+// Absolute, normalized, native-separator path used for most internal work.
+const prettyPathSchema = Schema.String.pipe(Schema.brand("PrettyPath"))
+
+function platform() {
+  return process.platform === "win32" ? path.win32 : path.posix
+}
+
+function parsePretty(input: string) {
+  if (!input) throw new TypeError("Expected absolute filesystem path, received empty string")
+  if (!platform().isAbsolute(input)) {
+    throw new TypeError(`Expected absolute filesystem path, received "${input}"`)
+  }
+  return prettyPathSchema.makeUnsafe(input)
+}
+
+function parseKey(input: string) {
+  parsePretty(input)
+  return pathKeySchema.makeUnsafe(input)
+}
+
+function parsePosix(input: string) {
+  if (!input) throw new TypeError("Expected POSIX path, received empty string")
+  if (input.includes("\\")) throw new TypeError(`Expected POSIX path without backslashes, received "${input}"`)
+  return posixPathSchema.makeUnsafe(input)
+}
+
+function parseRelative(input: string) {
+  if (!input) throw new TypeError("Expected relative path, received empty string")
+  if (platform().isAbsolute(input)) throw new TypeError(`Expected relative path, received "${input}"`)
+  return relativePathSchema.makeUnsafe(input)
+}
+
+function parseRepo(input: string) {
+  if (!input) throw new TypeError("Expected repository path, received empty string")
+  if (input.includes("\\")) throw new TypeError(`Expected repository path with forward slashes, received "${input}"`)
+  if (path.posix.isAbsolute(input)) throw new TypeError(`Expected repository-relative path, received "${input}"`)
+  return repoPathSchema.makeUnsafe(input)
+}
+
+function parseURI(input: string) {
+  if (!input) throw new TypeError("Expected file URI, received empty string")
+  let url: URL
+  try {
+    url = new URL(input)
+  } catch {
+    throw new TypeError(`Expected file URI, received "${input}"`)
+  }
+  if (url.protocol !== "file:") throw new TypeError(`Expected file URI, received "${input}"`)
+  return fileUriSchema.makeUnsafe(input)
+}
+
+export type PrettyPath = typeof prettyPathSchema.Type
+
+const pretty = zodString<PrettyPath>(parsePretty)
+
+export const PrettyPath = prettyPathSchema.pipe(
+  withStatics((schema: typeof prettyPathSchema) => ({
+    make: (input: string) => schema.makeUnsafe(input),
+    parse: parsePretty,
+    assert: (input: string): asserts input is PrettyPath => {
+      parsePretty(input)
+    },
+    input: pretty.input,
+    zod: pretty.zod,
+  })),
+)
+
+// Equality/map key form. Windows values are case-folded before branding.
+const pathKeySchema = Schema.String.pipe(Schema.brand("PathKey"))
+
+export type PathKey = typeof pathKeySchema.Type
+
+const key = zodString<PathKey>(parseKey)
+
+export const PathKey = pathKeySchema.pipe(
+  withStatics((schema: typeof pathKeySchema) => ({
+    make: (input: string) => schema.makeUnsafe(input),
+    parse: parseKey,
+    assert: (input: string): asserts input is PathKey => {
+      parseKey(input)
+    },
+    input: key.input,
+    zod: key.zod,
+  })),
+)
+
+// POSIX-slash form used where platform-neutral serialization matters.
+const posixPathSchema = Schema.String.pipe(Schema.brand("PosixPath"))
+
+export type PosixPath = typeof posixPathSchema.Type
+
+const posix = zodString<PosixPath>(parsePosix)
+
+export const PosixPath = posixPathSchema.pipe(
+  withStatics((schema: typeof posixPathSchema) => ({
+    make: (input: string) => schema.makeUnsafe(input),
+    parse: parsePosix,
+    assert: (input: string): asserts input is PosixPath => {
+      parsePosix(input)
+    },
+    input: posix.input,
+    zod: posix.zod,
+  })),
+)
+
+// Relative path produced from one already-normalized path to another.
+const relativePathSchema = Schema.String.pipe(Schema.brand("RelativePath"))
+
+export type RelativePath = typeof relativePathSchema.Type
+
+const relative = zodString<RelativePath>(parseRelative)
+
+export const RelativePath = relativePathSchema.pipe(
+  withStatics((schema: typeof relativePathSchema) => ({
+    make: (input: string) => schema.makeUnsafe(input),
+    parse: parseRelative,
+    assert: (input: string): asserts input is RelativePath => {
+      parseRelative(input)
+    },
+    input: relative.input,
+    zod: relative.zod,
+  })),
+)
+
+// Repository-relative path with stable forward slashes and optional trailing `/`.
+const repoPathSchema = Schema.String.pipe(Schema.brand("RepoPath"))
+
+export type RepoPath = typeof repoPathSchema.Type
+
+const repo = zodString<RepoPath>(parseRepo)
+
+export const RepoPath = repoPathSchema.pipe(
+  withStatics((schema: typeof repoPathSchema) => ({
+    make: (input: string) => schema.makeUnsafe(input),
+    parse: parseRepo,
+    assert: (input: string): asserts input is RepoPath => {
+      parseRepo(input)
+    },
+    input: repo.input,
+    zod: repo.zod,
+  })),
+)
+
+// `file://` URI string derived from a normalized filesystem path.
+const fileUriSchema = Schema.String.pipe(Schema.brand("FileURI"))
+
+export type FileURI = typeof fileUriSchema.Type
+
+const uri = zodString<FileURI>(parseURI)
+
+export const FileURI = fileUriSchema.pipe(
+  withStatics((schema: typeof fileUriSchema) => ({
+    make: (input: string) => schema.makeUnsafe(input),
+    parse: parseURI,
+    assert: (input: string): asserts input is FileURI => {
+      parseURI(input)
+    },
+    input: uri.input,
+    zod: uri.zod,
+  })),
+)
diff --git a/packages/opencode/src/permission/index.ts b/packages/opencode/src/permission/index.ts
index 63e6570189d8..97e6b248620d 100644
--- a/packages/opencode/src/permission/index.ts
+++ b/packages/opencode/src/permission/index.ts
@@ -1,19 +1,17 @@
 import { Bus } from "@/bus"
 import { BusEvent } from "@/bus/bus-event"
 import { Config } from "@/config/config"
+import { Path } from "@/path/path"
 import { InstanceState } from "@/effect/instance-state"
 import { makeRunPromise } from "@/effect/run-service"
 import { ProjectID } from "@/project/schema"
-import { Instance } from "@/project/instance"
 import { MessageID, SessionID } from "@/session/schema"
 import { PermissionTable } from "@/session/session.sql"
 import { Database, eq } from "@/storage/db"
 import { Log } from "@/util/log"
 import { Wildcard } from "@/util/wildcard"
 import { Deferred, Effect, Layer, Schema, ServiceMap } from "effect"
-import os from "os"
 import z from "zod"
-import { evaluate as evalRule } from "./evaluate"
 import { PermissionID } from "./schema"
 
 export namespace Permission {
@@ -131,8 +129,14 @@ export namespace Permission {
   }
 
   export function evaluate(permission: string, pattern: string, ...rulesets: Ruleset[]): Rule {
-    log.info("evaluate", { permission, pattern, ruleset: rulesets.flat() })
-    return evalRule(permission, pattern, ...rulesets)
+    const rules = rulesets.flat()
+    const text = normalize(permission, pattern)
+    log.info("evaluate", { permission, pattern: text, ruleset: rules })
+    const match = rules.findLast(
+      (rule) =>
+        Wildcard.match(permission, rule.permission) && Wildcard.match(text, normalize(permission, rule.pattern)),
+    )
+    return match ?? { action: "ask", permission, pattern: "*" }
   }
 
   export class Service extends ServiceMap.Service<Service, Interface>()("@opencode/Permission") {}
@@ -268,11 +272,12 @@ export namespace Permission {
   )
 
   function expand(pattern: string): string {
-    if (pattern.startsWith("~/")) return os.homedir() + pattern.slice(1)
-    if (pattern === "~") return os.homedir()
-    if (pattern.startsWith("$HOME/")) return os.homedir() + pattern.slice(5)
-    if (pattern.startsWith("$HOME")) return os.homedir() + pattern.slice(5)
-    return pattern
+    return Path.expand(pattern)
+  }
+
+  function normalize(permission: string, pattern: string) {
+    if (permission !== "external_directory") return pattern
+    return Path.canonical(pattern)
   }
 
   export function fromConfig(permission: Config.Permission) {
@@ -283,7 +288,11 @@ export namespace Permission {
         continue
       }
       ruleset.push(
-        ...Object.entries(value).map(([pattern, action]) => ({ permission: key, pattern: expand(pattern), action })),
+        ...Object.entries(value).map(([pattern, action]) => ({
+          permission: key,
+          pattern: normalize(key, expand(pattern)),
+          action,
+        })),
       )
     }
     return ruleset
@@ -320,3 +329,5 @@ export namespace Permission {
     return runPromise((s) => s.list())
   }
 }
+
+export import PermissionNext = Permission
diff --git a/packages/opencode/src/permission/schema.ts b/packages/opencode/src/permission/schema.ts
index bfa2b495779d..1a1fbbfad0ce 100644
--- a/packages/opencode/src/permission/schema.ts
+++ b/packages/opencode/src/permission/schema.ts
@@ -1,7 +1,7 @@
 import { Schema } from "effect"
-import z from "zod"
 
 import { Identifier } from "@/id/id"
+import { zodFrom } from "@/util/schema"
 import { Newtype } from "@/util/schema"
 
 export class PermissionID extends Newtype<PermissionID>()("PermissionID", Schema.String) {
@@ -9,9 +9,17 @@ export class PermissionID extends Newtype<PermissionID>()("PermissionID", Schema
     return this.makeUnsafe(id)
   }
 
+  static parse(id: string): PermissionID {
+    return this.makeUnsafe(Identifier.parse("permission", id))
+  }
+
+  static assert(id: string) {
+    Identifier.assert("permission", id)
+  }
+
   static ascending(id?: string): PermissionID {
     return this.makeUnsafe(Identifier.ascending("permission", id))
   }
 
-  static readonly zod = Identifier.schema("permission") as unknown as z.ZodType<PermissionID>
+  static readonly zod = zodFrom((id) => this.parse(id))
 }
diff --git a/packages/opencode/src/project/instance.ts b/packages/opencode/src/project/instance.ts
index 4c9b2e107bc8..58ab3478257c 100644
--- a/packages/opencode/src/project/instance.ts
+++ b/packages/opencode/src/project/instance.ts
@@ -1,6 +1,7 @@
 import { GlobalBus } from "@/bus/global"
 import { disposeInstance } from "@/effect/instance-registry"
-import { Filesystem } from "@/util/filesystem"
+import { Path } from "@/path/path"
+import type { PathKey, PrettyPath } from "@/path/schema"
 import { iife } from "@/util/iife"
 import { Log } from "@/util/log"
 import { Context } from "../util/context"
@@ -8,18 +9,18 @@ import { Project } from "./project"
 import { State } from "./state"
 
 export interface Shape {
-  directory: string
-  worktree: string
+  directory: PrettyPath
+  worktree: PrettyPath
   project: Project.Info
 }
 const context = Context.create<Shape>("instance")
-const cache = new Map<string, Promise<Shape>>()
+const cache = new Map<PathKey, Promise<Shape>>()
 
 const disposal = {
   all: undefined as Promise<void> | undefined,
 }
 
-function emit(directory: string) {
+function emit(directory: PrettyPath) {
   GlobalBus.emit("event", {
     directory,
     payload: {
@@ -31,7 +32,12 @@ function emit(directory: string) {
   })
 }
 
-function boot(input: { directory: string; init?: () => Promise<any>; project?: Project.Info; worktree?: string }) {
+function boot(input: {
+  directory: PrettyPath
+  init?: () => Promise<any>
+  project?: Project.Info
+  worktree?: PrettyPath
+}) {
   return iife(async () => {
     const ctx =
       input.project && input.worktree
@@ -52,26 +58,28 @@ function boot(input: { directory: string; init?: () => Promise<any>; project?: P
   })
 }
 
-function track(directory: string, next: Promise<Shape>) {
+function track(key: PathKey, next: Promise<Shape>) {
   const task = next.catch((error) => {
-    if (cache.get(directory) === task) cache.delete(directory)
+    if (cache.get(key) === task) cache.delete(key)
     throw error
   })
-  cache.set(directory, task)
+  cache.set(key, task)
   return task
 }
 
 export const Instance = {
   async provide<R>(input: { directory: string; init?: () => Promise<any>; fn: () => R }): Promise<R> {
-    const directory = Filesystem.resolve(input.directory)
-    let existing = cache.get(directory)
+    const key = Path.key(input.directory)
+    let existing = cache.get(key)
     if (!existing) {
-      Log.Default.info("creating instance", { directory })
       existing = track(
-        directory,
-        boot({
-          directory,
-          init: input.init,
+        key,
+        Path.truecase(input.directory).then((directory) => {
+          Log.Default.info("creating instance", { directory })
+          return boot({
+            directory,
+            init: input.init,
+          })
         }),
       )
     }
@@ -83,10 +91,10 @@ export const Instance = {
   get current() {
     return context.use()
   },
-  get directory() {
+  get directory(): PrettyPath {
     return context.use().directory
   },
-  get worktree() {
+  get worktree(): PrettyPath {
     return context.use().worktree
   },
   get project() {
@@ -98,11 +106,11 @@ export const Instance = {
    * Paths within the worktree but outside the working directory should not trigger external_directory permission.
    */
   containsPath(filepath: string) {
-    if (Filesystem.contains(Instance.directory, filepath)) return true
+    if (Path.contains(Instance.directory, filepath)) return true
     // Non-git projects set worktree to "/" which would match ANY absolute path.
     // Skip worktree check in this case to preserve external_directory permissions.
     if (Instance.worktree === "/") return false
-    return Filesystem.contains(Instance.worktree, filepath)
+    return Path.contains(Instance.worktree, filepath)
   },
   /**
    * Captures the current instance ALS context and returns a wrapper that
@@ -117,19 +125,33 @@ export const Instance = {
     return State.create(() => Instance.directory, init, dispose)
   },
   async reload(input: { directory: string; init?: () => Promise<any>; project?: Project.Info; worktree?: string }) {
-    const directory = Filesystem.resolve(input.directory)
+    const key = Path.key(input.directory)
+    const existing = cache.get(key)
+    const ctx = await existing?.catch(() => undefined)
+    const directory = ctx?.directory ?? (await Path.truecase(input.directory))
     Log.Default.info("reloading instance", { directory })
     await Promise.all([State.dispose(directory), disposeInstance(directory)])
-    cache.delete(directory)
-    const next = track(directory, boot({ ...input, directory }))
+    cache.delete(key)
+    const next = track(
+      key,
+      Promise.all([Promise.resolve(directory), input.worktree ? Path.truecase(input.worktree) : undefined]).then(
+        ([directory, worktree]) =>
+          boot({
+            ...input,
+            directory,
+            worktree,
+          }),
+      ),
+    )
     emit(directory)
     return await next
   },
   async dispose() {
     const directory = Instance.directory
+    const key = Path.key(directory)
     Log.Default.info("disposing instance", { directory })
     await Promise.all([State.dispose(directory), disposeInstance(directory)])
-    cache.delete(directory)
+    cache.delete(key)
     emit(directory)
   },
   async disposeAll() {
diff --git a/packages/opencode/src/project/project.sql.ts b/packages/opencode/src/project/project.sql.ts
index efbc400b5eec..0f3aa4c1abb3 100644
--- a/packages/opencode/src/project/project.sql.ts
+++ b/packages/opencode/src/project/project.sql.ts
@@ -1,16 +1,17 @@
 import { sqliteTable, text, integer } from "drizzle-orm/sqlite-core"
 import { Timestamps } from "../storage/schema.sql"
 import type { ProjectID } from "./schema"
+import type { PrettyPath } from "../path/schema"
 
 export const ProjectTable = sqliteTable("project", {
   id: text().$type<ProjectID>().primaryKey(),
-  worktree: text().notNull(),
+  worktree: text().$type<PrettyPath>().notNull(),
   vcs: text(),
   name: text(),
   icon_url: text(),
   icon_color: text(),
   ...Timestamps,
   time_initialized: integer(),
-  sandboxes: text({ mode: "json" }).notNull().$type<string[]>(),
+  sandboxes: text({ mode: "json" }).notNull().$type<PrettyPath[]>(),
   commands: text({ mode: "json" }).$type<{ start?: string }>(),
 })
diff --git a/packages/opencode/src/project/project.ts b/packages/opencode/src/project/project.ts
index 1cef41c85c91..f37ec5869cb5 100644
--- a/packages/opencode/src/project/project.ts
+++ b/packages/opencode/src/project/project.ts
@@ -1,7 +1,7 @@
 import z from "zod"
 import { Filesystem } from "../util/filesystem"
 import path from "path"
-import { and, Database, eq } from "../storage/db"
+import { Database, eq, and } from "../storage/db"
 import { ProjectTable } from "./project.sql"
 import { SessionTable } from "../session/session.sql"
 import { Log } from "../util/log"
@@ -15,26 +15,47 @@ import { git } from "../util/git"
 import { Glob } from "../util/glob"
 import { which } from "../util/which"
 import { ProjectID } from "./schema"
+import { Path } from "@/path/path"
+import { PrettyPath } from "@/path/schema"
 
 export namespace Project {
   const log = Log.create({ service: "project" })
 
-  function gitpath(cwd: string, name: string) {
-    if (!name) return cwd
+  function stored(input: string) {
+    return Path.truecaseSync(input)
+  }
+
+  function same(a: string, b: string) {
+    return Path.eq(a, b)
+  }
+
+  function uniq(list: readonly string[]) {
+    const seen = new Set<string>()
+    const out: PrettyPath[] = []
+    for (const item of list) {
+      const dir = stored(item)
+      const key = Path.key(dir)
+      if (seen.has(key)) continue
+      seen.add(key)
+      out.push(dir)
+    }
+    return out
+  }
+
+  async function gitpath(cwd: string, name: string) {
+    if (!name) return stored(cwd)
     // git output includes trailing newlines; keep path whitespace intact.
     name = name.replace(/[\r\n]+$/, "")
-    if (!name) return cwd
+    if (!name) return stored(cwd)
 
-    name = Filesystem.windowsPath(name)
-
-    if (path.isAbsolute(name)) return path.normalize(name)
-    return path.resolve(cwd, name)
+    if (Path.isAbsolute(name)) return await Path.truecase(name)
+    return await Path.truecase(Path.pretty(name, { cwd }))
   }
 
   export const Info = z
     .object({
       id: ProjectID.zod,
-      worktree: z.string(),
+      worktree: PrettyPath.zod,
       vcs: z.literal("git").optional(),
       name: z.string().optional(),
       icon: z
@@ -54,7 +75,7 @@ export namespace Project {
         updated: z.number(),
         initialized: z.number().optional(),
       }),
-      sandboxes: z.array(z.string()),
+      sandboxes: z.array(PrettyPath.zod),
     })
     .meta({
       ref: "Project",
@@ -73,8 +94,8 @@ export namespace Project {
         ? { url: row.icon_url ?? undefined, color: row.icon_color ?? undefined }
         : undefined
     return {
-      id: ProjectID.make(row.id),
-      worktree: row.worktree,
+      id: ProjectID.parse(row.id),
+      worktree: stored(row.worktree),
       vcs: row.vcs ? Info.shape.vcs.parse(row.vcs) : undefined,
       name: row.name ?? undefined,
       icon,
@@ -83,7 +104,7 @@ export namespace Project {
         updated: row.time_updated,
         initialized: row.time_initialized ?? undefined,
       },
-      sandboxes: row.sandboxes,
+      sandboxes: uniq(row.sandboxes),
       commands: row.commands ?? undefined,
     }
   }
@@ -91,19 +112,20 @@ export namespace Project {
   function readCachedId(dir: string) {
     return Filesystem.readText(path.join(dir, "opencode"))
       .then((x) => x.trim())
-      .then(ProjectID.make)
+      .then(ProjectID.parse)
       .catch(() => undefined)
   }
 
   export async function fromDirectory(directory: string) {
+    directory = await Path.truecase(directory)
     log.info("fromDirectory", { directory })
 
-    const data = await iife(async () => {
+    const data: { id: ProjectID; worktree: PrettyPath; sandbox: PrettyPath; vcs: Info["vcs"] } = await iife(async () => {
       const matches = Filesystem.up({ targets: [".git"], start: directory })
       const dotgit = await matches.next().then((x) => x.value)
       await matches.return()
       if (dotgit) {
-        let sandbox = path.dirname(dotgit)
+        let sandbox = await Path.truecase(path.dirname(dotgit))
 
         const gitBinary = which("git")
 
@@ -123,9 +145,9 @@ export namespace Project {
           cwd: sandbox,
         })
           .then(async (result) => {
-            const common = gitpath(sandbox, await result.text())
+            const common = await gitpath(sandbox, await result.text())
             // Avoid going to parent of sandbox when git-common-dir is empty.
-            return common === sandbox ? sandbox : path.dirname(common)
+            return same(common, sandbox) ? sandbox : stored(path.dirname(common))
           })
           .catch(() => undefined)
 
@@ -168,7 +190,7 @@ export namespace Project {
             }
           }
 
-          id = roots[0] ? ProjectID.make(roots[0]) : undefined
+          id = roots[0] ? ProjectID.parse(roots[0]) : undefined
           if (id) {
             // Write to common dir so the cache is shared across worktrees.
             await Filesystem.write(path.join(worktree, ".git", "opencode"), id).catch(() => undefined)
@@ -211,20 +233,20 @@ export namespace Project {
 
       return {
         id: ProjectID.global,
-        worktree: "/",
-        sandbox: "/",
+        worktree: PrettyPath.make("/"),
+        sandbox: PrettyPath.make("/"),
         vcs: Info.shape.vcs.parse(Flag.OPENCODE_FAKE_VCS),
       }
     })
 
     const row = Database.use((db) => db.select().from(ProjectTable).where(eq(ProjectTable.id, data.id)).get())
-    const existing = row
+    const existing: Info = row
       ? fromRow(row)
       : {
           id: data.id,
           worktree: data.worktree,
-          vcs: data.vcs as Info["vcs"],
-          sandboxes: [] as string[],
+          vcs: data.vcs,
+          sandboxes: [],
           time: {
             created: Date.now(),
             updated: Date.now(),
@@ -236,15 +258,17 @@ export namespace Project {
     const result: Info = {
       ...existing,
       worktree: data.worktree,
-      vcs: data.vcs as Info["vcs"],
+      sandboxes: uniq(existing.sandboxes),
+      vcs: data.vcs,
       time: {
         ...existing.time,
         updated: Date.now(),
       },
     }
-    if (data.sandbox !== result.worktree && !result.sandboxes.includes(data.sandbox))
-      result.sandboxes.push(data.sandbox)
-    result.sandboxes = result.sandboxes.filter((x) => existsSync(x))
+    if (!same(data.sandbox, result.worktree) && !result.sandboxes.some((item) => same(item, data.sandbox))) {
+      result.sandboxes.push(stored(data.sandbox))
+    }
+    result.sandboxes = uniq(result.sandboxes).filter((item) => existsSync(item))
     const insert = {
       id: result.id,
       worktree: result.worktree,
@@ -368,7 +392,6 @@ export namespace Project {
       commands: Info.shape.commands.optional(),
     }),
     async (input) => {
-      const id = ProjectID.make(input.projectID)
       const result = Database.use((db) =>
         db
           .update(ProjectTable)
@@ -379,7 +402,7 @@ export namespace Project {
             commands: input.commands,
             time_updated: Date.now(),
           })
-          .where(eq(ProjectTable.id, id))
+          .where(eq(ProjectTable.id, input.projectID))
           .returning()
           .get(),
       )
@@ -399,10 +422,10 @@ export namespace Project {
     const row = Database.use((db) => db.select().from(ProjectTable).where(eq(ProjectTable.id, id)).get())
     if (!row) return []
     const data = fromRow(row)
-    const valid: string[] = []
+    const valid: PrettyPath[] = []
     for (const dir of data.sandboxes) {
       const s = Filesystem.stat(dir)
-      if (s?.isDirectory()) valid.push(dir)
+      if (s?.isDirectory() && !valid.some((item) => same(item, dir))) valid.push(dir)
     }
     return valid
   }
@@ -410,8 +433,9 @@ export namespace Project {
   export async function addSandbox(id: ProjectID, directory: string) {
     const row = Database.use((db) => db.select().from(ProjectTable).where(eq(ProjectTable.id, id)).get())
     if (!row) throw new Error(`Project not found: ${id}`)
-    const sandboxes = [...row.sandboxes]
-    if (!sandboxes.includes(directory)) sandboxes.push(directory)
+    const dir = stored(directory)
+    const sandboxes = uniq(row.sandboxes)
+    if (!sandboxes.some((item) => same(item, dir))) sandboxes.push(dir)
     const result = Database.use((db) =>
       db
         .update(ProjectTable)
@@ -434,7 +458,8 @@ export namespace Project {
   export async function removeSandbox(id: ProjectID, directory: string) {
     const row = Database.use((db) => db.select().from(ProjectTable).where(eq(ProjectTable.id, id)).get())
     if (!row) throw new Error(`Project not found: ${id}`)
-    const sandboxes = row.sandboxes.filter((s) => s !== directory)
+    const dir = stored(directory)
+    const sandboxes = uniq(row.sandboxes).filter((item) => !same(item, dir))
     const result = Database.use((db) =>
       db
         .update(ProjectTable)
diff --git a/packages/opencode/src/project/schema.ts b/packages/opencode/src/project/schema.ts
index e904ff5a8433..55c35fcb5057 100644
--- a/packages/opencode/src/project/schema.ts
+++ b/packages/opencode/src/project/schema.ts
@@ -1,7 +1,11 @@
 import { Schema } from "effect"
-import z from "zod"
 
-import { withStatics } from "@/util/schema"
+import { withStatics, zodFrom } from "@/util/schema"
+
+function parse(id: string) {
+  if (!id) throw new TypeError("Expected project id, received empty string")
+  return id
+}
 
 const projectIdSchema = Schema.String.pipe(Schema.brand("ProjectID"))
 
@@ -11,6 +15,10 @@ export const ProjectID = projectIdSchema.pipe(
   withStatics((schema: typeof projectIdSchema) => ({
     global: schema.makeUnsafe("global"),
     make: (id: string) => schema.makeUnsafe(id),
-    zod: z.string().pipe(z.custom<ProjectID>()),
+    parse: (id: string) => schema.makeUnsafe(parse(id)),
+    assert: (id: string): asserts id is ProjectID => {
+      parse(id)
+    },
+    zod: zodFrom((id) => schema.makeUnsafe(parse(id))),
   })),
 )
diff --git a/packages/opencode/src/project/state.ts b/packages/opencode/src/project/state.ts
index a9dce565b5eb..18b085c3a1d7 100644
--- a/packages/opencode/src/project/state.ts
+++ b/packages/opencode/src/project/state.ts
@@ -1,3 +1,5 @@
+import { Path } from "@/path/path"
+import type { PathKey, PrettyPath } from "@/path/schema"
 import { Log } from "@/util/log"
 
 export namespace State {
@@ -7,14 +9,14 @@ export namespace State {
   }
 
   const log = Log.create({ service: "state" })
-  const recordsByKey = new Map<string, Map<any, Entry>>()
+  const recordsByKey = new Map<PathKey, Map<any, Entry>>()
 
-  export function create<S>(root: () => string, init: () => S, dispose?: (state: Awaited<S>) => Promise<void>) {
+  export function create<S>(root: () => PrettyPath, init: () => S, dispose?: (state: Awaited<S>) => Promise<void>) {
     return () => {
-      const key = root()
+      const key = Path.key(root())
       let entries = recordsByKey.get(key)
       if (!entries) {
-        entries = new Map<string, Entry>()
+        entries = new Map<any, Entry>()
         recordsByKey.set(key, entries)
       }
       const exists = entries.get(init)
@@ -28,7 +30,8 @@ export namespace State {
     }
   }
 
-  export async function dispose(key: string) {
+  export async function dispose(directory: PrettyPath) {
+    const key = Path.key(directory)
     const entries = recordsByKey.get(key)
     if (!entries) return
 
diff --git a/packages/opencode/src/provider/schema.ts b/packages/opencode/src/provider/schema.ts
index 71c8a1029cd3..c4bc9497ce23 100644
--- a/packages/opencode/src/provider/schema.ts
+++ b/packages/opencode/src/provider/schema.ts
@@ -1,7 +1,11 @@
 import { Schema } from "effect"
-import z from "zod"
 
-import { withStatics } from "@/util/schema"
+import { withStatics, zodFrom } from "@/util/schema"
+
+function parse(id: string, label: string) {
+  if (!id) throw new TypeError(`Expected ${label}, received empty string`)
+  return id
+}
 
 const providerIdSchema = Schema.String.pipe(Schema.brand("ProviderID"))
 
@@ -10,7 +14,11 @@ export type ProviderID = typeof providerIdSchema.Type
 export const ProviderID = providerIdSchema.pipe(
   withStatics((schema: typeof providerIdSchema) => ({
     make: (id: string) => schema.makeUnsafe(id),
-    zod: z.string().pipe(z.custom<ProviderID>()),
+    parse: (id: string) => schema.makeUnsafe(parse(id, "provider id")),
+    assert: (id: string): asserts id is ProviderID => {
+      parse(id, "provider id")
+    },
+    zod: zodFrom((id) => schema.makeUnsafe(parse(id, "provider id"))),
     // Well-known providers
     opencode: schema.makeUnsafe("opencode"),
     anthropic: schema.makeUnsafe("anthropic"),
@@ -33,6 +41,10 @@ export type ModelID = typeof modelIdSchema.Type
 export const ModelID = modelIdSchema.pipe(
   withStatics((schema: typeof modelIdSchema) => ({
     make: (id: string) => schema.makeUnsafe(id),
-    zod: z.string().pipe(z.custom<ModelID>()),
+    parse: (id: string) => schema.makeUnsafe(parse(id, "model id")),
+    assert: (id: string): asserts id is ModelID => {
+      parse(id, "model id")
+    },
+    zod: zodFrom((id) => schema.makeUnsafe(parse(id, "model id"))),
   })),
 )
diff --git a/packages/opencode/src/pty/schema.ts b/packages/opencode/src/pty/schema.ts
index 47b3196f0bd0..8f21e01edf99 100644
--- a/packages/opencode/src/pty/schema.ts
+++ b/packages/opencode/src/pty/schema.ts
@@ -1,5 +1,4 @@
 import { Schema } from "effect"
-import z from "zod"
 
 import { Identifier } from "@/id/id"
 import { withStatics } from "@/util/schema"
@@ -11,7 +10,11 @@ export type PtyID = typeof ptyIdSchema.Type
 export const PtyID = ptyIdSchema.pipe(
   withStatics((schema: typeof ptyIdSchema) => ({
     make: (id: string) => schema.makeUnsafe(id),
+    parse: (id: string) => schema.makeUnsafe(Identifier.parse("pty", id)),
+    assert: (id: string): asserts id is PtyID => {
+      Identifier.assert("pty", id)
+    },
     ascending: (id?: string) => schema.makeUnsafe(Identifier.ascending("pty", id)),
-    zod: Identifier.schema("pty").pipe(z.custom<PtyID>()),
+    zod: Identifier.schema<PtyID>("pty"),
   })),
 )
diff --git a/packages/opencode/src/question/schema.ts b/packages/opencode/src/question/schema.ts
index 38b930af11d5..657a8e757a5f 100644
--- a/packages/opencode/src/question/schema.ts
+++ b/packages/opencode/src/question/schema.ts
@@ -1,7 +1,7 @@
 import { Schema } from "effect"
-import z from "zod"
 
 import { Identifier } from "@/id/id"
+import { zodFrom } from "@/util/schema"
 import { Newtype } from "@/util/schema"
 
 export class QuestionID extends Newtype<QuestionID>()("QuestionID", Schema.String) {
@@ -9,9 +9,17 @@ export class QuestionID extends Newtype<QuestionID>()("QuestionID", Schema.Strin
     return this.makeUnsafe(id)
   }
 
+  static parse(id: string): QuestionID {
+    return this.makeUnsafe(Identifier.parse("question", id))
+  }
+
+  static assert(id: string) {
+    Identifier.assert("question", id)
+  }
+
   static ascending(id?: string): QuestionID {
     return this.makeUnsafe(Identifier.ascending("question", id))
   }
 
-  static readonly zod = Identifier.schema("question") as unknown as z.ZodType<QuestionID>
+  static readonly zod = zodFrom((id) => this.parse(id))
 }
diff --git a/packages/opencode/src/server/routes/experimental.ts b/packages/opencode/src/server/routes/experimental.ts
index 43be6f245e0e..c627ad85ee71 100644
--- a/packages/opencode/src/server/routes/experimental.ts
+++ b/packages/opencode/src/server/routes/experimental.ts
@@ -72,13 +72,13 @@ export const ExperimentalRoutes = lazy(() =>
       validator(
         "query",
         z.object({
-          provider: z.string(),
-          model: z.string(),
+          provider: ProviderID.zod,
+          model: ModelID.zod,
         }),
       ),
       async (c) => {
         const { provider, model } = c.req.valid("query")
-        const tools = await ToolRegistry.tools({ providerID: ProviderID.make(provider), modelID: ModelID.make(model) })
+        const tools = await ToolRegistry.tools({ providerID: provider, modelID: model })
         return c.json(
           tools.map((t) => ({
             id: t.id,
diff --git a/packages/opencode/src/server/server.ts b/packages/opencode/src/server/server.ts
index 7ead4df8a3cb..0601dd85babc 100644
--- a/packages/opencode/src/server/server.ts
+++ b/packages/opencode/src/server/server.ts
@@ -37,7 +37,7 @@ import type { ContentfulStatusCode } from "hono/utils/http-status"
 import { websocket } from "hono/bun"
 import { HTTPException } from "hono/http-exception"
 import { errors } from "./error"
-import { Filesystem } from "@/util/filesystem"
+import { Path } from "@/path/path"
 import { QuestionRoutes } from "./routes/question"
 import { PermissionRoutes } from "./routes/permission"
 import { GlobalRoutes } from "./routes/global"
@@ -47,8 +47,15 @@ import { lazy } from "@/util/lazy"
 // @ts-ignore This global is needed to prevent ai-sdk from logging warnings to stdout https://github.com/vercel/ai/blob/2dc67e0ef538307f21368db32d5a12345d98831b/packages/ai/src/logger/log-warnings.ts#L85
 globalThis.AI_SDK_LOG_WARNINGS = false
 
+function badInput(err: unknown) {
+  return new HTTPException(400, {
+    message: err instanceof Error ? err.message : "Invalid request",
+  })
+}
+
 export namespace Server {
   const log = Log.create({ service: "server" })
+  const os = process.platform === "win32" ? "windows" : process.platform === "darwin" ? "macos" : "linux"
 
   export const Default = lazy(() => createApp({}))
 
@@ -192,19 +199,25 @@ export namespace Server {
       .use(async (c, next) => {
         if (c.req.path === "/log") return next()
         const rawWorkspaceID = c.req.query("workspace") || c.req.header("x-opencode-workspace")
-        const raw = c.req.query("directory") || c.req.header("x-opencode-directory") || process.cwd()
-        const directory = Filesystem.resolve(
-          (() => {
-            try {
-              return decodeURIComponent(raw)
-            } catch {
-              return raw
-            }
-          })(),
-        )
+        const rawDirectory = c.req.query("directory") || c.req.header("x-opencode-directory")
+        const workspaceID = (() => {
+          try {
+            return rawWorkspaceID ? WorkspaceID.parse(rawWorkspaceID) : undefined
+          } catch (err) {
+            throw badInput(err)
+          }
+        })()
+        const directory = (() => {
+          try {
+            if (!rawDirectory) return Path.pretty(process.cwd())
+            return Path.ingress(rawDirectory, { label: "directory parameter" })
+          } catch (err) {
+            throw badInput(err)
+          }
+        })()
 
         return WorkspaceContext.provide({
-          workspaceID: rawWorkspaceID ? WorkspaceID.make(rawWorkspaceID) : undefined,
+          workspaceID,
           async fn() {
             return Instance.provide({
               directory,
@@ -287,6 +300,7 @@ export namespace Server {
                   schema: resolver(
                     z
                       .object({
+                        os: z.enum(["macos", "windows", "linux"]),
                         home: z.string(),
                         state: z.string(),
                         config: z.string(),
@@ -304,6 +318,7 @@ export namespace Server {
         }),
         async (c) => {
           return c.json({
+            os,
             home: Global.Path.home,
             state: Global.Path.state,
             config: Global.Path.config,
diff --git a/packages/opencode/src/session/index.ts b/packages/opencode/src/session/index.ts
index f2d436ff10d9..032f31084d29 100644
--- a/packages/opencode/src/session/index.ts
+++ b/packages/opencode/src/session/index.ts
@@ -32,6 +32,8 @@ import { Permission } from "@/permission"
 import { Global } from "@/global"
 import type { LanguageModelV2Usage } from "@ai-sdk/provider"
 import { iife } from "@/util/iife"
+import { Path } from "@/path/path"
+import { PrettyPath } from "@/path/schema"
 
 export namespace Session {
   const log = Log.create({ service: "session" })
@@ -50,6 +52,7 @@ export namespace Session {
   }
 
   type SessionRow = typeof SessionTable.$inferSelect
+  type SessionInsert = typeof SessionTable.$inferInsert
 
   export function fromRow(row: SessionRow): Info {
     const summary =
@@ -68,7 +71,7 @@ export namespace Session {
       slug: row.slug,
       projectID: row.project_id,
       workspaceID: row.workspace_id ?? undefined,
-      directory: row.directory,
+      directory: Path.truecaseSync(row.directory),
       parentID: row.parent_id ?? undefined,
       title: row.title,
       version: row.version,
@@ -85,14 +88,14 @@ export namespace Session {
     }
   }
 
-  export function toRow(info: Info) {
+  export function toRow(info: Info): SessionInsert {
     return {
       id: info.id,
       project_id: info.projectID,
       workspace_id: info.workspaceID,
       parent_id: info.parentID,
       slug: info.slug,
-      directory: info.directory,
+      directory: Path.truecaseSync(info.directory),
       title: info.title,
       version: info.version,
       share_url: info.share?.url,
@@ -125,7 +128,7 @@ export namespace Session {
       slug: z.string(),
       projectID: ProjectID.zod,
       workspaceID: WorkspaceID.zod.optional(),
-      directory: z.string(),
+      directory: PrettyPath.zod,
       parentID: SessionID.zod.optional(),
       summary: z
         .object({
@@ -167,7 +170,7 @@ export namespace Session {
     .object({
       id: ProjectID.zod,
       name: z.string().optional(),
-      worktree: z.string(),
+      worktree: PrettyPath.zod,
     })
     .meta({
       ref: "ProjectSummary",
@@ -179,7 +182,9 @@ export namespace Session {
   }).meta({
     ref: "GlobalSession",
   })
-  export type GlobalInfo = z.output<typeof GlobalInfo>
+  export type GlobalInfo = Omit<z.output<typeof GlobalInfo>, "project"> & {
+    project: ProjectInfo | null
+  }
 
   export const Event = {
     Created: BusEvent.define(
@@ -299,15 +304,16 @@ export namespace Session {
     title?: string
     parentID?: SessionID
     workspaceID?: WorkspaceID
-    directory: string
+    directory: PrettyPath
     permission?: Permission.Ruleset
   }) {
+    const dir = await Path.truecase(input.directory)
     const result: Info = {
       id: SessionID.descending(input.id),
       slug: Slug.create(),
       version: Installation.VERSION,
       projectID: Instance.project.id,
-      directory: input.directory,
+      directory: dir,
       workspaceID: input.workspaceID,
       parentID: input.parentID,
       title: input.title ?? createDefaultTitle(!!input.parentID),
@@ -547,13 +553,14 @@ export namespace Session {
   }) {
     const project = Instance.project
     const conditions = [eq(SessionTable.project_id, project.id)]
+    const dir = input?.directory ? Path.truecaseSync(input.directory) : undefined
+    if (dir) {
+      conditions.push(eq(SessionTable.directory, dir))
+    }
 
     if (WorkspaceContext.workspaceID) {
       conditions.push(eq(SessionTable.workspace_id, WorkspaceContext.workspaceID))
     }
-    if (input?.directory) {
-      conditions.push(eq(SessionTable.directory, input.directory))
-    }
     if (input?.roots) {
       conditions.push(isNull(SessionTable.parent_id))
     }
@@ -566,15 +573,14 @@ export namespace Session {
 
     const limit = input?.limit ?? 100
 
-    const rows = Database.use((db) =>
-      db
+    const rows = Database.use((db) => {
+      const query = db
         .select()
         .from(SessionTable)
         .where(and(...conditions))
         .orderBy(desc(SessionTable.time_updated))
-        .limit(limit)
-        .all(),
-    )
+      return query.limit(limit).all()
+    })
     for (const row of rows) {
       yield fromRow(row)
     }
@@ -590,10 +596,11 @@ export namespace Session {
     archived?: boolean
   }) {
     const conditions: SQL[] = []
-
-    if (input?.directory) {
-      conditions.push(eq(SessionTable.directory, input.directory))
+    const dir = input?.directory ? Path.truecaseSync(input.directory) : undefined
+    if (dir) {
+      conditions.push(eq(SessionTable.directory, dir))
     }
+
     if (input?.roots) {
       conditions.push(isNull(SessionTable.parent_id))
     }
@@ -620,7 +627,8 @@ export namespace Session {
               .from(SessionTable)
               .where(and(...conditions))
           : db.select().from(SessionTable)
-      return query.orderBy(desc(SessionTable.time_updated), desc(SessionTable.id)).limit(limit).all()
+      const sort = query.orderBy(desc(SessionTable.time_updated), desc(SessionTable.id))
+      return sort.limit(limit).all()
     })
 
     const ids = [...new Set(rows.map((row) => row.project_id))]
@@ -638,7 +646,7 @@ export namespace Session {
         projects.set(item.id, {
           id: item.id,
           name: item.name ?? undefined,
-          worktree: item.worktree,
+          worktree: item.worktree === "/" ? item.worktree : Path.truecaseSync(item.worktree),
         })
       }
     }
diff --git a/packages/opencode/src/session/instruction.ts b/packages/opencode/src/session/instruction.ts
index 86f73d0fd238..a40299dc6e06 100644
--- a/packages/opencode/src/session/instruction.ts
+++ b/packages/opencode/src/session/instruction.ts
@@ -1,9 +1,9 @@
-import path from "path"
-import os from "os"
 import { Global } from "../global"
 import { Filesystem } from "../util/filesystem"
 import { Config } from "../config/config"
+import { Path } from "../path/path"
 import { Instance } from "../project/instance"
+import type { PathKey, PrettyPath } from "@/path/schema"
 import { Flag } from "@/flag/flag"
 import { Log } from "../util/log"
 import { Glob } from "../util/glob"
@@ -20,11 +20,11 @@ const FILES = [
 function globalFiles() {
   const files = []
   if (Flag.OPENCODE_CONFIG_DIR) {
-    files.push(path.join(Flag.OPENCODE_CONFIG_DIR, "AGENTS.md"))
+    files.push(Path.pretty("AGENTS.md", { cwd: Flag.OPENCODE_CONFIG_DIR }))
   }
-  files.push(path.join(Global.Path.config, "AGENTS.md"))
+  files.push(Path.pretty("AGENTS.md", { cwd: Global.Path.config }))
   if (!Flag.OPENCODE_DISABLE_CLAUDE_CODE_PROMPT) {
-    files.push(path.join(os.homedir(), ".claude", "CLAUDE.md"))
+    files.push(Path.expand("~/.claude/CLAUDE.md"))
   }
   return files
 }
@@ -45,17 +45,17 @@ async function resolveRelative(instruction: string): Promise<string[]> {
 export namespace InstructionPrompt {
   const state = Instance.state(() => {
     return {
-      claims: new Map<string, Set<string>>(),
+      claims: new Map<string, Set<PathKey>>(),
     }
   })
 
-  function isClaimed(messageID: string, filepath: string) {
+  function isClaimed(messageID: string, filepath: PathKey) {
     const claimed = state().claims.get(messageID)
     if (!claimed) return false
     return claimed.has(filepath)
   }
 
-  function claim(messageID: string, filepath: string) {
+  function claim(messageID: string, filepath: PathKey) {
     const current = state()
     let claimed = current.claims.get(messageID)
     if (!claimed) {
@@ -71,14 +71,14 @@ export namespace InstructionPrompt {
 
   export async function systemPaths() {
     const config = await Config.get()
-    const paths = new Set<string>()
+    const paths = new Set<PrettyPath>()
 
     if (!Flag.OPENCODE_DISABLE_PROJECT_CONFIG) {
       for (const file of FILES) {
         const matches = await Filesystem.findUp(file, Instance.directory, Instance.worktree)
         if (matches.length > 0) {
           matches.forEach((p) => {
-            paths.add(path.resolve(p))
+            paths.add(Path.pretty(p))
           })
           break
         }
@@ -87,7 +87,7 @@ export namespace InstructionPrompt {
 
     for (const file of globalFiles()) {
       if (await Filesystem.exists(file)) {
-        paths.add(path.resolve(file))
+        paths.add(Path.pretty(file))
         break
       }
     }
@@ -95,18 +95,17 @@ export namespace InstructionPrompt {
     if (config.instructions) {
       for (let instruction of config.instructions) {
         if (instruction.startsWith("https://") || instruction.startsWith("http://")) continue
-        if (instruction.startsWith("~/")) {
-          instruction = path.join(os.homedir(), instruction.slice(2))
-        }
-        const matches = path.isAbsolute(instruction)
-          ? await Glob.scan(path.basename(instruction), {
-              cwd: path.dirname(instruction),
+        instruction = Path.expand(instruction)
+        const file = Path.isAbsolute(instruction) ? Path.pretty(instruction) : undefined
+        const matches = file
+          ? await Glob.scan(Path.repoName(file), {
+              cwd: Path.parent(file),
               absolute: true,
               include: "file",
             }).catch(() => [])
           : await resolveRelative(instruction)
         matches.forEach((p) => {
-          paths.add(path.resolve(p))
+          paths.add(Path.pretty(p))
         })
       }
     }
@@ -142,7 +141,7 @@ export namespace InstructionPrompt {
   }
 
   export function loaded(messages: MessageV2.WithParts[]) {
-    const paths = new Set<string>()
+    const paths = new Set<PathKey>()
     for (const msg of messages) {
       for (const part of msg.parts) {
         if (part.type === "tool" && part.tool === "read" && part.state.status === "completed") {
@@ -150,7 +149,7 @@ export namespace InstructionPrompt {
           const loaded = part.state.metadata?.loaded
           if (!loaded || !Array.isArray(loaded)) continue
           for (const p of loaded) {
-            if (typeof p === "string") paths.add(p)
+            if (typeof p === "string") paths.add(Path.key(p))
           }
         }
       }
@@ -160,31 +159,33 @@ export namespace InstructionPrompt {
 
   export async function find(dir: string) {
     for (const file of FILES) {
-      const filepath = path.resolve(path.join(dir, file))
+      const filepath = Path.pretty(file, { cwd: dir })
       if (await Filesystem.exists(filepath)) return filepath
     }
   }
 
-  export async function resolve(messages: MessageV2.WithParts[], filepath: string, messageID: string) {
-    const system = await systemPaths()
+  export async function resolve(messages: MessageV2.WithParts[], filepath: PrettyPath, messageID: string) {
+    const system = new Set(Array.from(await systemPaths(), (item) => Path.key(item)))
     const already = loaded(messages)
-    const results: { filepath: string; content: string }[] = []
-
-    const target = path.resolve(filepath)
-    let current = path.dirname(target)
-    const root = path.resolve(Instance.directory)
-
-    while (current.startsWith(root) && current !== root) {
-      const found = await find(current)
-
-      if (found && found !== target && !system.has(found) && !already.has(found) && !isClaimed(messageID, found)) {
-        claim(messageID, found)
-        const content = await Filesystem.readText(found).catch(() => undefined)
-        if (content) {
-          results.push({ filepath: found, content: "Instructions from: " + found + "\n" + content })
-        }
-      }
-      current = path.dirname(current)
+    const results: { filepath: PrettyPath; content: string }[] = []
+
+    const target = Path.truecaseSync(filepath)
+    const targetKey = Path.key(target)
+    const root = Path.truecaseSync(Instance.directory)
+    const rootKey = Path.key(root)
+
+    for (const dir of Path.up(Path.parent(target), { stop: root })) {
+      if (Path.key(dir) === rootKey) break
+      const found = await find(dir)
+      if (!found) continue
+      const hit = Path.truecaseSync(found)
+      const hitKey = Path.key(hit)
+
+      if (hitKey === targetKey || system.has(hitKey) || already.has(hitKey) || isClaimed(messageID, hitKey)) continue
+      claim(messageID, hitKey)
+      const content = await Filesystem.readText(hit).catch(() => undefined)
+      if (!content) continue
+      results.push({ filepath: Path.pretty(hit), content: "Instructions from: " + hit + "\n" + content })
     }
 
     return results
diff --git a/packages/opencode/src/session/message-v2.ts b/packages/opencode/src/session/message-v2.ts
index f1335f6f21a3..61bdc71a6f7d 100644
--- a/packages/opencode/src/session/message-v2.ts
+++ b/packages/opencode/src/session/message-v2.ts
@@ -11,11 +11,13 @@ import { MessageTable, PartTable, SessionTable } from "./session.sql"
 import { ProviderTransform } from "@/provider/transform"
 import { STATUS_CODES } from "http"
 import { Storage } from "@/storage/storage"
+import { PrettyPath, type FileURI } from "@/path/schema"
 import { ProviderError } from "@/provider/error"
 import { iife } from "@/util/iife"
 import type { SystemError } from "bun"
 import type { Provider } from "@/provider/provider"
 import { ModelID, ProviderID } from "@/provider/schema"
+import { Path } from "@/path/path"
 
 export namespace MessageV2 {
   export function isMedia(mime: string) {
@@ -145,20 +147,22 @@ export namespace MessageV2 {
 
   export const FileSource = FilePartSourceBase.extend({
     type: z.literal("file"),
-    path: z.string(),
+    path: PrettyPath.zod,
   }).meta({
     ref: "FileSource",
   })
+  export type FileSource = z.infer<typeof FileSource>
 
   export const SymbolSource = FilePartSourceBase.extend({
     type: z.literal("symbol"),
-    path: z.string(),
+    path: PrettyPath.zod,
     range: LSP.Range,
     name: z.string(),
     kind: z.number().int(),
   }).meta({
     ref: "SymbolSource",
   })
+  export type SymbolSource = z.infer<typeof SymbolSource>
 
   export const ResourceSource = FilePartSourceBase.extend({
     type: z.literal("resource"),
@@ -167,10 +171,14 @@ export namespace MessageV2 {
   }).meta({
     ref: "ResourceSource",
   })
+  export type ResourceSource = Omit<z.infer<typeof ResourceSource>, "uri"> & {
+    uri: string | FileURI
+  }
 
   export const FilePartSource = z.discriminatedUnion("type", [FileSource, SymbolSource, ResourceSource]).meta({
     ref: "FilePartSource",
   })
+  export type FilePartSource = FileSource | SymbolSource | ResourceSource
 
   export const FilePart = PartBase.extend({
     type: z.literal("file"),
@@ -420,8 +428,8 @@ export namespace MessageV2 {
     mode: z.string(),
     agent: z.string(),
     path: z.object({
-      cwd: z.string(),
-      root: z.string(),
+      cwd: PrettyPath.zod,
+      root: PrettyPath.zod,
     }),
     summary: z.boolean().optional(),
     cost: z.number(),
@@ -509,20 +517,58 @@ export namespace MessageV2 {
     },
   }
 
-  const info = (row: typeof MessageTable.$inferSelect) =>
-    ({
-      ...row.data,
+  function assistantPath(input: MessageV2.Assistant["path"]) {
+    return {
+      cwd: Path.from(input.cwd, { label: "assistant cwd" }),
+      root: Path.from(input.root, { label: "assistant root" }),
+    }
+  }
+
+  function partSource(input: MessageV2.FilePartSource): MessageV2.FilePartSource {
+    if (input.type === "resource") return input
+    return {
+      ...input,
+      path: Path.from(input.path, { label: `${input.type} source path` }),
+    }
+  }
+
+  const info = (row: typeof MessageTable.$inferSelect): MessageV2.Info => {
+    const data = row.data as MessageV2.Info
+    if (data.role === "user") {
+      return {
+        ...data,
+        id: row.id,
+        sessionID: row.session_id,
+      }
+    }
+
+    return {
+      ...data,
       id: row.id,
       sessionID: row.session_id,
-    }) as MessageV2.Info
+      path: assistantPath(data.path),
+    }
+  }
+
+  const part = (row: typeof PartTable.$inferSelect): MessageV2.Part => {
+    const data = row.data as MessageV2.Part
+    if (data.type !== "file" || !data.source) {
+      return {
+        ...data,
+        id: row.id,
+        sessionID: row.session_id,
+        messageID: row.message_id,
+      }
+    }
 
-  const part = (row: typeof PartTable.$inferSelect) =>
-    ({
-      ...row.data,
+    return {
+      ...data,
       id: row.id,
       sessionID: row.session_id,
       messageID: row.message_id,
-    }) as MessageV2.Part
+      source: partSource(data.source),
+    }
+  }
 
   const older = (row: Cursor) =>
     or(
@@ -853,9 +899,7 @@ export namespace MessageV2 {
     const rows = Database.use((db) =>
       db.select().from(PartTable).where(eq(PartTable.message_id, message_id)).orderBy(PartTable.id).all(),
     )
-    return rows.map(
-      (row) => ({ ...row.data, id: row.id, sessionID: row.session_id, messageID: row.message_id }) as MessageV2.Part,
-    )
+    return rows.map(part)
   })
 
   export const get = fn(
diff --git a/packages/opencode/src/session/prompt.ts b/packages/opencode/src/session/prompt.ts
index dca8085c5b2e..7d505b9dba7d 100644
--- a/packages/opencode/src/session/prompt.ts
+++ b/packages/opencode/src/session/prompt.ts
@@ -1,5 +1,4 @@
 import path from "path"
-import os from "os"
 import fs from "fs/promises"
 import z from "zod"
 import { Filesystem } from "../util/filesystem"
@@ -33,11 +32,11 @@ import { Flag } from "../flag/flag"
 import { ulid } from "ulid"
 import { spawn } from "child_process"
 import { Command } from "../command"
-import { pathToFileURL, fileURLToPath } from "url"
 import { ConfigMarkdown } from "../config/markdown"
 import { SessionSummary } from "./summary"
 import { NamedError } from "@opencode-ai/util/error"
 import { fn } from "@/util/fn"
+import { Path } from "@/path/path"
 import { SessionProcessor } from "./processor"
 import { TaskTool } from "@/tool/task"
 import { Tool } from "@/tool/tool"
@@ -163,7 +162,7 @@ export namespace SessionPrompt {
     const session = await Session.get(input.sessionID)
     await SessionRevert.cleanup(session)
 
-    const message = await createUserMessage(input)
+    const message = await createUserMessage(input, session)
     await Session.touch(input.sessionID)
 
     // this is backwards compatibility for allowing `tools` to be specified when
@@ -202,9 +201,8 @@ export namespace SessionPrompt {
         const name = match[1]
         if (seen.has(name)) return
         seen.add(name)
-        const filepath = name.startsWith("~/")
-          ? path.join(os.homedir(), name.slice(2))
-          : path.resolve(Instance.worktree, name)
+        const file = Path.expand(name)
+        const filepath = Path.pretty(file, { cwd: Instance.worktree })
 
         const stats = await fs.stat(filepath).catch(() => undefined)
         if (!stats) {
@@ -221,7 +219,7 @@ export namespace SessionPrompt {
         if (stats.isDirectory()) {
           parts.push({
             type: "file",
-            url: pathToFileURL(filepath).href,
+            url: String(Path.uri(filepath)),
             filename: name,
             mime: "application/x-directory",
           })
@@ -230,7 +228,7 @@ export namespace SessionPrompt {
 
         parts.push({
           type: "file",
-          url: pathToFileURL(filepath).href,
+          url: String(Path.uri(filepath)),
           filename: name,
           mime: "text/plain",
         })
@@ -963,8 +961,9 @@ export namespace SessionPrompt {
     })
   }
 
-  async function createUserMessage(input: PromptInput) {
+  async function createUserMessage(input: PromptInput, session: Session.Info) {
     const agent = await Agent.get(input.agent ?? (await Agent.defaultAgent()))
+    const ruleset = Permission.merge(agent.permission, session.permission ?? [])
 
     const model = input.model ?? agent.model ?? (await lastModel(input.sessionID))
     const full =
@@ -992,7 +991,7 @@ export namespace SessionPrompt {
     type Draft<T> = T extends MessageV2.Part ? Omit<T, "id"> & { id?: string } : never
     const assign = (part: Draft<MessageV2.Part>): MessageV2.Part => ({
       ...part,
-      id: part.id ? PartID.make(part.id) : PartID.ascending(),
+      id: part.id ? PartID.parse(part.id) : PartID.ascending(),
     })
 
     const parts = await Promise.all(
@@ -1094,9 +1093,7 @@ export namespace SessionPrompt {
               break
             case "file:":
               log.info("file", { mime: part.mime })
-              // have to normalize, symbol search returns absolute paths
-              // Decode the pathname since URL constructor doesn't automatically decode it
-              const filepath = fileURLToPath(part.url)
+              const filepath = Path.fromURI(part.url)
               const s = Filesystem.stat(filepath)
 
               if (s?.isDirectory()) {
@@ -1152,16 +1149,20 @@ export namespace SessionPrompt {
 
                 await ReadTool.init()
                   .then(async (t) => {
-                    const model = await Provider.getModel(info.model.providerID, info.model.modelID)
                     const readCtx: Tool.Context = {
                       sessionID: input.sessionID,
                       abort: new AbortController().signal,
-                      agent: input.agent!,
+                      agent: agent.name,
                       messageID: info.id,
-                      extra: { bypassCwdCheck: true, model },
                       messages: [],
                       metadata: async () => {},
-                      ask: async () => {},
+                      ask: async (req) => {
+                        await Permission.ask({
+                          ...req,
+                          sessionID: input.sessionID,
+                          ruleset,
+                        })
+                      },
                     }
                     const result = await t.execute(args, readCtx)
                     pieces.push({
@@ -1215,12 +1216,17 @@ export namespace SessionPrompt {
                 const listCtx: Tool.Context = {
                   sessionID: input.sessionID,
                   abort: new AbortController().signal,
-                  agent: input.agent!,
+                  agent: agent.name,
                   messageID: info.id,
-                  extra: { bypassCwdCheck: true },
                   messages: [],
                   metadata: async () => {},
-                  ask: async () => {},
+                  ask: async (req) => {
+                    await Permission.ask({
+                      ...req,
+                      sessionID: input.sessionID,
+                      ruleset,
+                    })
+                  },
                 }
                 const result = await ReadTool.init().then((t) => t.execute(args, listCtx))
                 return [
diff --git a/packages/opencode/src/session/schema.ts b/packages/opencode/src/session/schema.ts
index 540643c49186..54e8611608ec 100644
--- a/packages/opencode/src/session/schema.ts
+++ b/packages/opencode/src/session/schema.ts
@@ -1,5 +1,4 @@
 import { Schema } from "effect"
-import z from "zod"
 
 import { Identifier } from "@/id/id"
 import { withStatics } from "@/util/schema"
@@ -8,8 +7,12 @@ export const SessionID = Schema.String.pipe(
   Schema.brand("SessionID"),
   withStatics((s) => ({
     make: (id: string) => s.makeUnsafe(id),
+    parse: (id: string) => s.makeUnsafe(Identifier.parse("session", id)),
+    assert: (id: string): asserts id is Schema.Schema.Type<typeof s> => {
+      Identifier.assert("session", id)
+    },
     descending: (id?: string) => s.makeUnsafe(Identifier.descending("session", id)),
-    zod: Identifier.schema("session").pipe(z.custom<Schema.Schema.Type<typeof s>>()),
+    zod: Identifier.schema<Schema.Schema.Type<typeof s>>("session"),
   })),
 )
 
@@ -19,8 +22,12 @@ export const MessageID = Schema.String.pipe(
   Schema.brand("MessageID"),
   withStatics((s) => ({
     make: (id: string) => s.makeUnsafe(id),
+    parse: (id: string) => s.makeUnsafe(Identifier.parse("message", id)),
+    assert: (id: string): asserts id is Schema.Schema.Type<typeof s> => {
+      Identifier.assert("message", id)
+    },
     ascending: (id?: string) => s.makeUnsafe(Identifier.ascending("message", id)),
-    zod: Identifier.schema("message").pipe(z.custom<Schema.Schema.Type<typeof s>>()),
+    zod: Identifier.schema<Schema.Schema.Type<typeof s>>("message"),
   })),
 )
 
@@ -30,8 +37,12 @@ export const PartID = Schema.String.pipe(
   Schema.brand("PartID"),
   withStatics((s) => ({
     make: (id: string) => s.makeUnsafe(id),
+    parse: (id: string) => s.makeUnsafe(Identifier.parse("part", id)),
+    assert: (id: string): asserts id is Schema.Schema.Type<typeof s> => {
+      Identifier.assert("part", id)
+    },
     ascending: (id?: string) => s.makeUnsafe(Identifier.ascending("part", id)),
-    zod: Identifier.schema("part").pipe(z.custom<Schema.Schema.Type<typeof s>>()),
+    zod: Identifier.schema<Schema.Schema.Type<typeof s>>("part"),
   })),
 )
 
diff --git a/packages/opencode/src/session/session.sql.ts b/packages/opencode/src/session/session.sql.ts
index 189a596873a3..9d5ac6d0a3d5 100644
--- a/packages/opencode/src/session/session.sql.ts
+++ b/packages/opencode/src/session/session.sql.ts
@@ -6,6 +6,7 @@ import type { Permission } from "../permission"
 import type { ProjectID } from "../project/schema"
 import type { SessionID, MessageID, PartID } from "./schema"
 import type { WorkspaceID } from "../control-plane/schema"
+import type { PrettyPath } from "../path/schema"
 import { Timestamps } from "../storage/schema.sql"
 
 type PartData = Omit<MessageV2.Part, "id" | "sessionID" | "messageID">
@@ -22,7 +23,7 @@ export const SessionTable = sqliteTable(
     workspace_id: text().$type<WorkspaceID>(),
     parent_id: text().$type<SessionID>(),
     slug: text().notNull(),
-    directory: text().notNull(),
+    directory: text().$type<PrettyPath>().notNull(),
     title: text().notNull(),
     version: text().notNull(),
     share_url: text(),
diff --git a/packages/opencode/src/session/summary.ts b/packages/opencode/src/session/summary.ts
index 898b93f3f98c..f95bdcb02bf4 100644
--- a/packages/opencode/src/session/summary.ts
+++ b/packages/opencode/src/session/summary.ts
@@ -9,6 +9,7 @@ import { Snapshot } from "@/snapshot"
 
 import { Storage } from "@/storage/storage"
 import { Bus } from "@/bus"
+import { Path } from "@/path/path"
 import { NotFoundError } from "@/storage/db"
 
 export namespace SessionSummary {
@@ -132,7 +133,7 @@ export namespace SessionSummary {
         if (file === item.file) return item
         return {
           ...item,
-          file,
+          file: Path.repo(file),
         }
       })
       const changed = next.some((item, i) => item.file !== diffs[i]?.file)
diff --git a/packages/opencode/src/skill/index.ts b/packages/opencode/src/skill/index.ts
index 43a22219edc3..acca12ad104e 100644
--- a/packages/opencode/src/skill/index.ts
+++ b/packages/opencode/src/skill/index.ts
@@ -1,4 +1,3 @@
-import os from "os"
 import path from "path"
 import { pathToFileURL } from "url"
 import z from "zod"
@@ -10,6 +9,7 @@ import { InstanceState } from "@/effect/instance-state"
 import { makeRunPromise } from "@/effect/run-service"
 import { Flag } from "@/flag/flag"
 import { Global } from "@/global"
+import { Path } from "@/path/path"
 import { Permission } from "@/permission"
 import { Filesystem } from "@/util/filesystem"
 import { Config } from "../config/config"
@@ -146,8 +146,7 @@ export namespace Skill {
 
       const cfg = await Config.get()
       for (const item of cfg.skills?.paths ?? []) {
-        const expanded = item.startsWith("~/") ? path.join(os.homedir(), item.slice(2)) : item
-        const dir = path.isAbsolute(expanded) ? expanded : path.join(directory, expanded)
+        const dir = Path.pretty(Path.expand(item), { cwd: directory })
         if (!(await Filesystem.isDir(dir))) {
           log.warn("skill path not found", { path: dir })
           continue
diff --git a/packages/opencode/src/snapshot/index.ts b/packages/opencode/src/snapshot/index.ts
index 5f8c5aeffd48..36bda138ac5b 100644
--- a/packages/opencode/src/snapshot/index.ts
+++ b/packages/opencode/src/snapshot/index.ts
@@ -6,6 +6,8 @@ import z from "zod"
 import { InstanceState } from "@/effect/instance-state"
 import { makeRunPromise } from "@/effect/run-service"
 import { AppFileSystem } from "@/filesystem"
+import { Path } from "@/path/path"
+import type { PathKey } from "@/path/schema"
 import { Config } from "../config/config"
 import { Global } from "../global"
 import { Log } from "../util/log"
@@ -192,7 +194,7 @@ export namespace Snapshot {
                   .split("\n")
                   .map((x) => x.trim())
                   .filter(Boolean)
-                  .map((x) => path.join(state.worktree, x).replaceAll("\\", "/")),
+                  .map((x) => Path.pretty(x, { cwd: state.worktree })),
               }
             })
 
@@ -217,17 +219,18 @@ export namespace Snapshot {
             })
 
             const revert = Effect.fnUntraced(function* (patches: Snapshot.Patch[]) {
-              const seen = new Set<string>()
+              const seen = new Set<PathKey>()
               for (const item of patches) {
                 for (const file of item.files) {
-                  if (seen.has(file)) continue
-                  seen.add(file)
+                  const id = Path.key(file)
+                  if (seen.has(id)) continue
+                  seen.add(id)
+                  const rel = Path.rel(state.worktree, file)
                   log.info("reverting", { file, hash: item.hash })
-                  const result = yield* git([...core, ...args(["checkout", item.hash, "--", file])], {
+                  const result = yield* git([...core, ...args(["checkout", item.hash, "--", rel])], {
                     cwd: state.worktree,
                   })
                   if (result.code !== 0) {
-                    const rel = path.relative(state.worktree, file)
                     const tree = yield* git([...core, ...args(["ls-tree", item.hash, "--", rel])], {
                       cwd: state.worktree,
                     })
@@ -298,7 +301,7 @@ export namespace Snapshot {
                 const additions = binary ? 0 : parseInt(adds)
                 const deletions = binary ? 0 : parseInt(dels)
                 result.push({
-                  file,
+                  file: Path.repo(file),
                   before,
                   after,
                   additions: Number.isFinite(additions) ? additions : 0,
diff --git a/packages/opencode/src/tool/apply_patch.ts b/packages/opencode/src/tool/apply_patch.ts
index 06293b6eba6e..9fa262531041 100644
--- a/packages/opencode/src/tool/apply_patch.ts
+++ b/packages/opencode/src/tool/apply_patch.ts
@@ -10,9 +10,10 @@ import { createTwoFilesPatch, diffLines } from "diff"
 import { assertExternalDirectory } from "./external-directory"
 import { trimDiff } from "./edit"
 import { LSP } from "../lsp"
-import { Filesystem } from "../util/filesystem"
 import DESCRIPTION from "./apply_patch.txt"
 import { File } from "../file"
+import { Path } from "@/path/path"
+import type { PrettyPath } from "@/path/schema"
 
 const PatchParams = z.object({
   patchText: z.string().describe("The full patch text that describes all changes to be made"),
@@ -45,20 +46,21 @@ export const ApplyPatchTool = Tool.define("apply_patch", {
 
     // Validate file paths and check permissions
     const fileChanges: Array<{
-      filePath: string
+      filePath: PrettyPath
       oldContent: string
       newContent: string
       type: "add" | "update" | "delete" | "move"
-      movePath?: string
+      movePath?: PrettyPath
       diff: string
       additions: number
       deletions: number
     }> = []
 
     let totalDiff = ""
+    const rel = (input: string) => String(Path.rel(Instance.worktree, input)).replaceAll("\\", "/")
 
     for (const hunk of hunks) {
-      const filePath = path.resolve(Instance.directory, hunk.path)
+      const filePath = Path.pretty(hunk.path, { cwd: Instance.directory })
       await assertExternalDirectory(ctx, filePath)
 
       switch (hunk.type) {
@@ -116,7 +118,7 @@ export const ApplyPatchTool = Tool.define("apply_patch", {
             if (change.removed) deletions += change.count || 0
           }
 
-          const movePath = hunk.move_path ? path.resolve(Instance.directory, hunk.move_path) : undefined
+          const movePath = hunk.move_path ? Path.pretty(hunk.move_path, { cwd: Instance.directory }) : undefined
           await assertExternalDirectory(ctx, movePath)
 
           fileChanges.push({
@@ -161,7 +163,7 @@ export const ApplyPatchTool = Tool.define("apply_patch", {
     // Build per-file metadata for UI rendering (used for both permission and result)
     const files = fileChanges.map((change) => ({
       filePath: change.filePath,
-      relativePath: path.relative(Instance.worktree, change.movePath ?? change.filePath).replaceAll("\\", "/"),
+      relativePath: rel(change.movePath ?? change.filePath),
       type: change.type,
       diff: change.diff,
       before: change.oldContent,
@@ -172,7 +174,11 @@ export const ApplyPatchTool = Tool.define("apply_patch", {
     }))
 
     // Check permissions if needed
-    const relativePaths = fileChanges.map((c) => path.relative(Instance.worktree, c.filePath).replaceAll("\\", "/"))
+    const relativePaths = [...new Set(fileChanges.flatMap((change) => {
+      const items = [change.filePath]
+      if (change.movePath) items.push(change.movePath)
+      return items.map(rel)
+    }))]
     await ctx.ask({
       permission: "edit",
       patterns: relativePaths,
@@ -242,13 +248,13 @@ export const ApplyPatchTool = Tool.define("apply_patch", {
     // Generate output summary
     const summaryLines = fileChanges.map((change) => {
       if (change.type === "add") {
-        return `A ${path.relative(Instance.worktree, change.filePath).replaceAll("\\", "/")}`
+        return `A ${rel(change.filePath)}`
       }
       if (change.type === "delete") {
-        return `D ${path.relative(Instance.worktree, change.filePath).replaceAll("\\", "/")}`
+        return `D ${rel(change.filePath)}`
       }
       const target = change.movePath ?? change.filePath
-      return `M ${path.relative(Instance.worktree, target).replaceAll("\\", "/")}`
+      return `M ${rel(target)}`
     })
     let output = `Success. Updated the following files:\n${summaryLines.join("\n")}`
 
@@ -257,14 +263,13 @@ export const ApplyPatchTool = Tool.define("apply_patch", {
     for (const change of fileChanges) {
       if (change.type === "delete") continue
       const target = change.movePath ?? change.filePath
-      const normalized = Filesystem.normalizePath(target)
-      const issues = diagnostics[normalized] ?? []
+      const issues = LSP.diagnosticsFor(target, diagnostics)?.diagnostics ?? []
       const errors = issues.filter((item) => item.severity === 1)
       if (errors.length > 0) {
         const limited = errors.slice(0, MAX_DIAGNOSTICS_PER_FILE)
         const suffix =
           errors.length > MAX_DIAGNOSTICS_PER_FILE ? `\n... and ${errors.length - MAX_DIAGNOSTICS_PER_FILE} more` : ""
-        output += `\n\nLSP errors detected in ${path.relative(Instance.worktree, target).replaceAll("\\", "/")}, please fix:\n<diagnostics file="${target}">\n${limited.map(LSP.Diagnostic.pretty).join("\n")}${suffix}\n</diagnostics>`
+        output += `\n\nLSP errors detected in ${rel(target)}, please fix:\n<diagnostics file="${target}">\n${limited.map(LSP.Diagnostic.pretty).join("\n")}${suffix}\n</diagnostics>`
       }
     }
 
diff --git a/packages/opencode/src/tool/bash.ts b/packages/opencode/src/tool/bash.ts
index 50ae4abac8de..0fa2eefb3c39 100644
--- a/packages/opencode/src/tool/bash.ts
+++ b/packages/opencode/src/tool/bash.ts
@@ -7,7 +7,6 @@ import { Log } from "../util/log"
 import { Instance } from "../project/instance"
 import { lazy } from "@/util/lazy"
 import { Language } from "web-tree-sitter"
-import fs from "fs/promises"
 
 import { Filesystem } from "@/util/filesystem"
 import { fileURLToPath } from "url"
@@ -17,6 +16,8 @@ import { Shell } from "@/shell/shell"
 import { BashArity } from "@/permission/arity"
 import { Truncate } from "./truncate"
 import { Plugin } from "@/plugin"
+import { Path } from "@/path/path"
+import { resolveExternalDirectory } from "./external-directory"
 
 const MAX_METADATA_LENGTH = 30_000
 const DEFAULT_TIMEOUT = Flag.OPENCODE_EXPERIMENTAL_BASH_DEFAULT_TIMEOUT_MS || 2 * 60 * 1000
@@ -76,7 +77,15 @@ export const BashTool = Tool.define("bash", async () => {
         ),
     }),
     async execute(params, ctx) {
-      const cwd = params.workdir || Instance.directory
+      const root = Path.physical(Instance.directory)
+      const worktree = Instance.worktree === "/" ? undefined : Path.physical(Instance.worktree)
+      const inside = async (input: string) => {
+        const file = await Path.physical(input)
+        if (Path.contains(await root, file)) return true
+        if (!worktree) return false
+        return Path.contains(await worktree, file)
+      }
+      const cwd = await Path.physical(params.workdir || Instance.directory, { cwd: Instance.directory })
       if (params.timeout !== undefined && params.timeout < 0) {
         throw new Error(`Invalid timeout value: ${params.timeout}. Timeout must be a positive number.`)
       }
@@ -85,8 +94,8 @@ export const BashTool = Tool.define("bash", async () => {
       if (!tree) {
         throw new Error("Failed to parse command")
       }
-      const directories = new Set<string>()
-      if (!Instance.containsPath(cwd)) directories.add(cwd)
+      const dirs = new Set<string>()
+      if (!(await inside(cwd))) dirs.add(cwd)
       const patterns = new Set<string>()
       const always = new Set<string>()
 
@@ -116,15 +125,11 @@ export const BashTool = Tool.define("bash", async () => {
         if (["cd", "rm", "cp", "mv", "mkdir", "touch", "chmod", "chown", "cat"].includes(command[0])) {
           for (const arg of command.slice(1)) {
             if (arg.startsWith("-") || (command[0] === "chmod" && arg.startsWith("+"))) continue
-            const resolved = await fs.realpath(path.resolve(cwd, arg)).catch(() => "")
+            const resolved = await Path.physical(arg, { cwd })
             log.info("resolved path", { arg, resolved })
-            if (resolved) {
-              const normalized =
-                process.platform === "win32" ? Filesystem.windowsPath(resolved).replace(/\//g, "\\") : resolved
-              if (!Instance.containsPath(normalized)) {
-                const dir = (await Filesystem.isDir(normalized)) ? normalized : path.dirname(normalized)
-                directories.add(dir)
-              }
+            if (!(await inside(resolved))) {
+              const dir = (await Filesystem.isDir(resolved)) ? resolved : path.dirname(resolved)
+              dirs.add(dir)
             }
           }
         }
@@ -136,12 +141,14 @@ export const BashTool = Tool.define("bash", async () => {
         }
       }
 
-      if (directories.size > 0) {
-        const globs = Array.from(directories).map((dir) => {
-          // Preserve POSIX-looking paths with /s, even on Windows
-          if (dir.startsWith("/")) return `${dir.replace(/[\\/]+$/, "")}/*`
-          return path.join(dir, "*")
-        })
+      if (dirs.size > 0) {
+        const globs = Array.from(
+          new Set(
+            await Promise.all(
+              Array.from(dirs).map((dir) => resolveExternalDirectory(dir, { kind: "directory" }).then((x) => x.glob)),
+            ),
+          ),
+        )
         await ctx.ask({
           permission: "external_directory",
           patterns: globs,
diff --git a/packages/opencode/src/tool/edit.ts b/packages/opencode/src/tool/edit.ts
index 1a7614fc17fb..195158956124 100644
--- a/packages/opencode/src/tool/edit.ts
+++ b/packages/opencode/src/tool/edit.ts
@@ -4,7 +4,6 @@
 // https://github.com/cline/cline/blob/main/evals/diff-edits/diff-apply/diff-06-26-25.ts
 
 import z from "zod"
-import * as path from "path"
 import { Tool } from "./tool"
 import { LSP } from "../lsp"
 import { createTwoFilesPatch, diffLines } from "diff"
@@ -17,6 +16,7 @@ import { Filesystem } from "../util/filesystem"
 import { Instance } from "../project/instance"
 import { Snapshot } from "@/snapshot"
 import { assertExternalDirectory } from "./external-directory"
+import { Path } from "@/path/path"
 
 const MAX_DIAGNOSTICS_PER_FILE = 20
 
@@ -50,7 +50,7 @@ export const EditTool = Tool.define("edit", {
       throw new Error("No changes to apply: oldString and newString are identical.")
     }
 
-    const filePath = path.isAbsolute(params.filePath) ? params.filePath : path.join(Instance.directory, params.filePath)
+    const filePath = Path.pretty(params.filePath, { cwd: Instance.directory })
     await assertExternalDirectory(ctx, filePath)
 
     let diff = ""
@@ -63,7 +63,7 @@ export const EditTool = Tool.define("edit", {
         diff = trimDiff(createTwoFilesPatch(filePath, filePath, contentOld, contentNew))
         await ctx.ask({
           permission: "edit",
-          patterns: [path.relative(Instance.worktree, filePath)],
+          patterns: [String(Path.rel(Instance.worktree, filePath))],
           always: ["*"],
           metadata: {
             filepath: filePath,
@@ -99,7 +99,7 @@ export const EditTool = Tool.define("edit", {
       )
       await ctx.ask({
         permission: "edit",
-        patterns: [path.relative(Instance.worktree, filePath)],
+        patterns: [String(Path.rel(Instance.worktree, filePath))],
         always: ["*"],
         metadata: {
           filepath: filePath,
@@ -123,7 +123,7 @@ export const EditTool = Tool.define("edit", {
     })
 
     const filediff: Snapshot.FileDiff = {
-      file: filePath,
+      file: Path.repoFrom(Instance.directory, filePath),
       before: contentOld,
       after: contentNew,
       additions: 0,
@@ -145,8 +145,7 @@ export const EditTool = Tool.define("edit", {
     let output = "Edit applied successfully."
     await LSP.touchFile(filePath, true)
     const diagnostics = await LSP.diagnostics()
-    const normalizedFilePath = Filesystem.normalizePath(filePath)
-    const issues = diagnostics[normalizedFilePath] ?? []
+    const issues = LSP.diagnosticsFor(filePath, diagnostics)?.diagnostics ?? []
     const errors = issues.filter((item) => item.severity === 1)
     if (errors.length > 0) {
       const limited = errors.slice(0, MAX_DIAGNOSTICS_PER_FILE)
@@ -161,7 +160,7 @@ export const EditTool = Tool.define("edit", {
         diff,
         filediff,
       },
-      title: `${path.relative(Instance.worktree, filePath)}`,
+      title: String(Path.rel(Instance.worktree, filePath)),
       output,
     }
   },
diff --git a/packages/opencode/src/tool/external-directory.ts b/packages/opencode/src/tool/external-directory.ts
index 5d8885b2ad46..598a9e041828 100644
--- a/packages/opencode/src/tool/external-directory.ts
+++ b/packages/opencode/src/tool/external-directory.ts
@@ -1,32 +1,45 @@
 import path from "path"
 import type { Tool } from "./tool"
 import { Instance } from "../project/instance"
+import { Path } from "@/path/path"
 
 type Kind = "file" | "directory"
 
 type Options = {
-  bypass?: boolean
   kind?: Kind
 }
 
+export async function resolveExternalDirectory(target: string, options?: Options) {
+  const file = await Path.physical(target)
+  const kind = options?.kind ?? "file"
+  const parentDir = kind === "directory" ? file : path.dirname(file)
+  return {
+    file,
+    parentDir,
+    glob: Path.externalGlob(parentDir),
+  }
+}
+
 export async function assertExternalDirectory(ctx: Tool.Context, target?: string, options?: Options) {
   if (!target) return
 
-  if (options?.bypass) return
+  const hit = await resolveExternalDirectory(target, options)
+  const dir = await Path.physical(Instance.directory)
 
-  if (Instance.containsPath(target)) return
+  if (Path.contains(dir, hit.file)) return
 
-  const kind = options?.kind ?? "file"
-  const parentDir = kind === "directory" ? target : path.dirname(target)
-  const glob = path.join(parentDir, "*").replaceAll("\\", "/")
+  if (Instance.worktree !== "/") {
+    const root = await Path.physical(Instance.worktree)
+    if (Path.contains(root, hit.file)) return
+  }
 
   await ctx.ask({
     permission: "external_directory",
-    patterns: [glob],
-    always: [glob],
+    patterns: [hit.glob],
+    always: [hit.glob],
     metadata: {
       filepath: target,
-      parentDir,
+      parentDir: hit.parentDir,
     },
   })
 }
diff --git a/packages/opencode/src/tool/glob.ts b/packages/opencode/src/tool/glob.ts
index a2611246c66f..08b16f866e8e 100644
--- a/packages/opencode/src/tool/glob.ts
+++ b/packages/opencode/src/tool/glob.ts
@@ -1,11 +1,11 @@
 import z from "zod"
-import path from "path"
 import { Tool } from "./tool"
 import { Filesystem } from "../util/filesystem"
 import DESCRIPTION from "./glob.txt"
 import { Ripgrep } from "../file/ripgrep"
 import { Instance } from "../project/instance"
 import { assertExternalDirectory } from "./external-directory"
+import { Path } from "@/path/path"
 
 export const GlobTool = Tool.define("glob", {
   description: DESCRIPTION,
@@ -29,8 +29,7 @@ export const GlobTool = Tool.define("glob", {
       },
     })
 
-    let search = params.path ?? Instance.directory
-    search = path.isAbsolute(search) ? search : path.resolve(Instance.directory, search)
+    const search = Path.pretty(params.path ?? ".", { cwd: Instance.directory })
     await assertExternalDirectory(ctx, search, { kind: "directory" })
 
     const limit = 100
@@ -45,7 +44,7 @@ export const GlobTool = Tool.define("glob", {
         truncated = true
         break
       }
-      const full = path.resolve(search, file)
+      const full = Path.pretty(file, { cwd: search })
       const stats = Filesystem.stat(full)?.mtime.getTime() ?? 0
       files.push({
         path: full,
@@ -67,7 +66,7 @@ export const GlobTool = Tool.define("glob", {
     }
 
     return {
-      title: path.relative(Instance.worktree, search),
+      title: String(Path.rel(Instance.worktree, search)),
       metadata: {
         count: files.length,
         truncated,
diff --git a/packages/opencode/src/tool/grep.ts b/packages/opencode/src/tool/grep.ts
index 82e7ac1667e1..8ff47e61fbdc 100644
--- a/packages/opencode/src/tool/grep.ts
+++ b/packages/opencode/src/tool/grep.ts
@@ -7,8 +7,8 @@ import { Process } from "../util/process"
 
 import DESCRIPTION from "./grep.txt"
 import { Instance } from "../project/instance"
-import path from "path"
 import { assertExternalDirectory } from "./external-directory"
+import { Path } from "@/path/path"
 
 const MAX_LINE_LENGTH = 2000
 
@@ -35,8 +35,7 @@ export const GrepTool = Tool.define("grep", {
       },
     })
 
-    let searchPath = params.path ?? Instance.directory
-    searchPath = path.isAbsolute(searchPath) ? searchPath : path.resolve(Instance.directory, searchPath)
+    const searchPath = Path.pretty(params.path ?? ".", { cwd: Instance.directory })
     await assertExternalDirectory(ctx, searchPath, { kind: "directory" })
 
     const rgPath = await Ripgrep.filepath()
@@ -90,11 +89,12 @@ export const GrepTool = Tool.define("grep", {
       const lineNum = parseInt(lineNumStr, 10)
       const lineText = lineTextParts.join("|")
 
-      const stats = Filesystem.stat(filePath)
+      const file = Path.pretty(filePath, { cwd: searchPath })
+      const stats = Filesystem.stat(file)
       if (!stats) continue
 
       matches.push({
-        path: filePath,
+        path: file,
         modTime: stats.mtime.getTime(),
         lineNum,
         lineText,
diff --git a/packages/opencode/src/tool/ls.ts b/packages/opencode/src/tool/ls.ts
index b848e969b74e..4aaec36d64c2 100644
--- a/packages/opencode/src/tool/ls.ts
+++ b/packages/opencode/src/tool/ls.ts
@@ -5,6 +5,7 @@ import DESCRIPTION from "./ls.txt"
 import { Instance } from "../project/instance"
 import { Ripgrep } from "../file/ripgrep"
 import { assertExternalDirectory } from "./external-directory"
+import { Path } from "@/path/path"
 
 export const IGNORE_PATTERNS = [
   "node_modules/",
@@ -42,7 +43,7 @@ export const ListTool = Tool.define("list", {
     ignore: z.array(z.string()).describe("List of glob patterns to ignore").optional(),
   }),
   async execute(params, ctx) {
-    const searchPath = path.resolve(Instance.directory, params.path || ".")
+    const searchPath = Path.pretty(params.path ?? ".", { cwd: Instance.directory })
     await assertExternalDirectory(ctx, searchPath, { kind: "directory" })
 
     await ctx.ask({
@@ -57,27 +58,24 @@ export const ListTool = Tool.define("list", {
     const ignoreGlobs = IGNORE_PATTERNS.map((p) => `!${p}*`).concat(params.ignore?.map((p) => `!${p}`) || [])
     const files = []
     for await (const file of Ripgrep.files({ cwd: searchPath, glob: ignoreGlobs, signal: ctx.abort })) {
-      files.push(file)
+      files.push(String(Path.repo(file)))
       if (files.length >= LIMIT) break
     }
 
-    // Build directory structure
-    const dirs = new Set<string>()
+    const dirs = new Set<string>(["."])
     const filesByDir = new Map<string, string[]>()
 
     for (const file of files) {
-      const dir = path.dirname(file)
-      const parts = dir === "." ? [] : dir.split("/")
-
-      // Add all parent directories
-      for (let i = 0; i <= parts.length; i++) {
-        const dirPath = i === 0 ? "." : parts.slice(0, i).join("/")
-        dirs.add(dirPath)
+      const dir = String(Path.repoParent(file))
+      let current = dir
+      while (true) {
+        dirs.add(current)
+        if (current === ".") break
+        current = String(Path.repoParent(current))
       }
 
-      // Add file to its directory
       if (!filesByDir.has(dir)) filesByDir.set(dir, [])
-      filesByDir.get(dir)!.push(path.basename(file))
+      filesByDir.get(dir)!.push(Path.repoName(file))
     }
 
     function renderDir(dirPath: string, depth: number): string {
@@ -85,20 +83,18 @@ export const ListTool = Tool.define("list", {
       let output = ""
 
       if (depth > 0) {
-        output += `${indent}${path.basename(dirPath)}/\n`
+        output += `${indent}${Path.repoName(dirPath)}/\n`
       }
 
       const childIndent = "  ".repeat(depth + 1)
       const children = Array.from(dirs)
-        .filter((d) => path.dirname(d) === dirPath && d !== dirPath)
+        .filter((d) => d !== "." && d !== dirPath && String(Path.repoParent(d)) === dirPath)
         .sort()
 
-      // Render subdirectories first
       for (const child of children) {
         output += renderDir(child, depth + 1)
       }
 
-      // Render files
       const files = filesByDir.get(dirPath) || []
       for (const file of files.sort()) {
         output += `${childIndent}${file}\n`
@@ -107,10 +103,11 @@ export const ListTool = Tool.define("list", {
       return output
     }
 
-    const output = `${searchPath}/\n` + renderDir(".", 0)
+    const root = searchPath.endsWith(path.sep) ? searchPath : searchPath + path.sep
+    const output = `${root}\n` + renderDir(".", 0)
 
     return {
-      title: path.relative(Instance.worktree, searchPath),
+      title: String(Path.rel(Instance.worktree, searchPath)),
       metadata: {
         count: files.length,
         truncated: files.length >= LIMIT,
diff --git a/packages/opencode/src/tool/lsp.ts b/packages/opencode/src/tool/lsp.ts
index 52aef0f9e3f2..de59a1114a97 100644
--- a/packages/opencode/src/tool/lsp.ts
+++ b/packages/opencode/src/tool/lsp.ts
@@ -1,12 +1,11 @@
 import z from "zod"
 import { Tool } from "./tool"
-import path from "path"
 import { LSP } from "../lsp"
 import DESCRIPTION from "./lsp.txt"
 import { Instance } from "../project/instance"
-import { pathToFileURL } from "url"
 import { assertExternalDirectory } from "./external-directory"
 import { Filesystem } from "../util/filesystem"
+import { Path } from "@/path/path"
 
 const operations = [
   "goToDefinition",
@@ -29,7 +28,7 @@ export const LspTool = Tool.define("lsp", {
     character: z.number().int().min(1).describe("The character offset (1-based, as shown in editors)"),
   }),
   execute: async (args, ctx) => {
-    const file = path.isAbsolute(args.filePath) ? args.filePath : path.join(Instance.directory, args.filePath)
+    const file = Path.pretty(args.filePath, { cwd: Instance.directory })
     await assertExternalDirectory(ctx, file)
 
     await ctx.ask({
@@ -38,14 +37,14 @@ export const LspTool = Tool.define("lsp", {
       always: ["*"],
       metadata: {},
     })
-    const uri = pathToFileURL(file).href
+    const uri = String(Path.uri(file))
     const position = {
       file,
       line: args.line - 1,
       character: args.character - 1,
     }
 
-    const relPath = path.relative(Instance.worktree, file)
+    const relPath = String(Path.rel(Instance.worktree, file))
     const title = `${args.operation} ${relPath}:${args.line}:${args.character}`
 
     const exists = await Filesystem.exists(file)
diff --git a/packages/opencode/src/tool/read.ts b/packages/opencode/src/tool/read.ts
index 85be8f9d394d..5896e047dbb7 100644
--- a/packages/opencode/src/tool/read.ts
+++ b/packages/opencode/src/tool/read.ts
@@ -11,6 +11,7 @@ import { Instance } from "../project/instance"
 import { assertExternalDirectory } from "./external-directory"
 import { InstructionPrompt } from "../session/instruction"
 import { Filesystem } from "../util/filesystem"
+import { Path } from "@/path/path"
 
 const DEFAULT_READ_LIMIT = 2000
 const MAX_LINE_LENGTH = 2000
@@ -29,18 +30,12 @@ export const ReadTool = Tool.define("read", {
     if (params.offset !== undefined && params.offset < 1) {
       throw new Error("offset must be greater than or equal to 1")
     }
-    let filepath = params.filePath
-    if (!path.isAbsolute(filepath)) {
-      filepath = path.resolve(Instance.directory, filepath)
-    }
-    const title = path.relative(Instance.worktree, filepath)
+    const filepath = Path.pretty(params.filePath, { cwd: Instance.directory })
+    const title = String(Path.rel(Instance.worktree, filepath))
 
     const stat = Filesystem.stat(filepath)
 
-    await assertExternalDirectory(ctx, filepath, {
-      bypass: Boolean(ctx.extra?.["bypassCwdCheck"]),
-      kind: stat?.isDirectory() ? "directory" : "file",
-    })
+    await assertExternalDirectory(ctx, filepath, { kind: stat?.isDirectory() ? "directory" : "file" })
 
     await ctx.ask({
       permission: "read",
diff --git a/packages/opencode/src/tool/schema.ts b/packages/opencode/src/tool/schema.ts
index 93f0f9a71f75..34d094e7debe 100644
--- a/packages/opencode/src/tool/schema.ts
+++ b/packages/opencode/src/tool/schema.ts
@@ -1,5 +1,4 @@
 import { Schema } from "effect"
-import z from "zod"
 
 import { Identifier } from "@/id/id"
 import { withStatics } from "@/util/schema"
@@ -11,7 +10,11 @@ export type ToolID = typeof toolIdSchema.Type
 export const ToolID = toolIdSchema.pipe(
   withStatics((schema: typeof toolIdSchema) => ({
     make: (id: string) => schema.makeUnsafe(id),
+    parse: (id: string) => schema.makeUnsafe(Identifier.parse("tool", id)),
+    assert: (id: string): asserts id is ToolID => {
+      Identifier.assert("tool", id)
+    },
     ascending: (id?: string) => schema.makeUnsafe(Identifier.ascending("tool", id)),
-    zod: Identifier.schema("tool").pipe(z.custom<ToolID>()),
+    zod: Identifier.schema<ToolID>("tool"),
   })),
 )
diff --git a/packages/opencode/src/tool/task.ts b/packages/opencode/src/tool/task.ts
index e3781126d0c1..b6ad23baa2c0 100644
--- a/packages/opencode/src/tool/task.ts
+++ b/packages/opencode/src/tool/task.ts
@@ -4,7 +4,6 @@ import z from "zod"
 import { Session } from "../session"
 import { SessionID, MessageID } from "../session/schema"
 import { MessageV2 } from "../session/message-v2"
-import { Identifier } from "../id/id"
 import { Agent } from "../agent/agent"
 import { SessionPrompt } from "../session/prompt"
 import { iife } from "@/util/iife"
@@ -67,7 +66,7 @@ export const TaskTool = Tool.define("task", async (ctx) => {
 
       const session = await iife(async () => {
         if (params.task_id) {
-          const found = await Session.get(SessionID.make(params.task_id)).catch(() => {})
+          const found = await Session.get(SessionID.parse(params.task_id)).catch(() => {})
           if (found) return found
         }
 
diff --git a/packages/opencode/src/tool/write.ts b/packages/opencode/src/tool/write.ts
index 83474a543ca1..45761e5c8a00 100644
--- a/packages/opencode/src/tool/write.ts
+++ b/packages/opencode/src/tool/write.ts
@@ -1,5 +1,4 @@
 import z from "zod"
-import * as path from "path"
 import { Tool } from "./tool"
 import { LSP } from "../lsp"
 import { createTwoFilesPatch } from "diff"
@@ -12,6 +11,7 @@ import { Filesystem } from "../util/filesystem"
 import { Instance } from "../project/instance"
 import { trimDiff } from "./edit"
 import { assertExternalDirectory } from "./external-directory"
+import { Path } from "@/path/path"
 
 const MAX_DIAGNOSTICS_PER_FILE = 20
 const MAX_PROJECT_DIAGNOSTICS_FILES = 5
@@ -23,7 +23,7 @@ export const WriteTool = Tool.define("write", {
     filePath: z.string().describe("The absolute path to the file to write (must be absolute, not relative)"),
   }),
   async execute(params, ctx) {
-    const filepath = path.isAbsolute(params.filePath) ? params.filePath : path.join(Instance.directory, params.filePath)
+    const filepath = Path.pretty(params.filePath, { cwd: Instance.directory })
     await assertExternalDirectory(ctx, filepath)
 
     const exists = await Filesystem.exists(filepath)
@@ -33,7 +33,7 @@ export const WriteTool = Tool.define("write", {
     const diff = trimDiff(createTwoFilesPatch(filepath, filepath, contentOld, params.content))
     await ctx.ask({
       permission: "edit",
-      patterns: [path.relative(Instance.worktree, filepath)],
+      patterns: [String(Path.rel(Instance.worktree, filepath))],
       always: ["*"],
       metadata: {
         filepath,
@@ -54,7 +54,7 @@ export const WriteTool = Tool.define("write", {
     let output = "Wrote file successfully."
     await LSP.touchFile(filepath, true)
     const diagnostics = await LSP.diagnostics()
-    const normalizedFilepath = Filesystem.normalizePath(filepath)
+    const current = LSP.diagnosticsFor(filepath, diagnostics)
     let projectDiagnosticsCount = 0
     for (const [file, issues] of Object.entries(diagnostics)) {
       const errors = issues.filter((item) => item.severity === 1)
@@ -62,7 +62,7 @@ export const WriteTool = Tool.define("write", {
       const limited = errors.slice(0, MAX_DIAGNOSTICS_PER_FILE)
       const suffix =
         errors.length > MAX_DIAGNOSTICS_PER_FILE ? `\n... and ${errors.length - MAX_DIAGNOSTICS_PER_FILE} more` : ""
-      if (file === normalizedFilepath) {
+      if (file === current?.path) {
         output += `\n\nLSP errors detected in this file, please fix:\n<diagnostics file="${filepath}">\n${limited.map(LSP.Diagnostic.pretty).join("\n")}${suffix}\n</diagnostics>`
         continue
       }
@@ -72,7 +72,7 @@ export const WriteTool = Tool.define("write", {
     }
 
     return {
-      title: path.relative(Instance.worktree, filepath),
+      title: String(Path.rel(Instance.worktree, filepath)),
       metadata: {
         diagnostics,
         filepath,
diff --git a/packages/opencode/src/util/filesystem.ts b/packages/opencode/src/util/filesystem.ts
index 37f00c6b9c8e..ec74e9fe8188 100644
--- a/packages/opencode/src/util/filesystem.ts
+++ b/packages/opencode/src/util/filesystem.ts
@@ -1,12 +1,21 @@
 import { chmod, mkdir, readFile, writeFile } from "fs/promises"
 import { createWriteStream, existsSync, statSync } from "fs"
 import { lookup } from "mime-types"
-import { realpathSync } from "fs"
-import { dirname, join, relative, resolve as pathResolve } from "path"
+import { dirname } from "path"
 import { Readable } from "stream"
 import { pipeline } from "stream/promises"
+import { Path } from "@/path/path"
 import { Glob } from "./glob"
 
+async function* searchUp(targets: string[], start: string, stop?: string) {
+  for (const dir of Path.up(start, { stop })) {
+    for (const target of targets) {
+      const file = Path.join(dir, target)
+      if (await Filesystem.exists(file)) yield file
+    }
+  }
+}
+
 export namespace Filesystem {
   // Fast sync version for metadata checks
   export async function exists(p: string): Promise<boolean> {
@@ -99,92 +108,22 @@ export namespace Filesystem {
     return lookup(p) || "application/octet-stream"
   }
 
-  /**
-   * On Windows, normalize a path to its canonical casing using the filesystem.
-   * This is needed because Windows paths are case-insensitive but LSP servers
-   * may return paths with different casing than what we send them.
-   */
-  export function normalizePath(p: string): string {
-    if (process.platform !== "win32") return p
-    try {
-      return realpathSync.native(p)
-    } catch {
-      return p
-    }
-  }
-
-  // We cannot rely on path.resolve() here because git.exe may come from Git Bash, Cygwin, or MSYS2, so we need to translate these paths at the boundary.
-  // Also resolves symlinks so that callers using the result as a cache key
-  // always get the same canonical path for a given physical directory.
-  export function resolve(p: string): string {
-    const resolved = pathResolve(windowsPath(p))
-    try {
-      return normalizePath(realpathSync(resolved))
-    } catch (e) {
-      if (isEnoent(e)) return normalizePath(resolved)
-      throw e
-    }
-  }
-
-  export function windowsPath(p: string): string {
-    if (process.platform !== "win32") return p
-    return (
-      p
-        .replace(/^\/([a-zA-Z]):(?:[\\/]|$)/, (_, drive) => `${drive.toUpperCase()}:/`)
-        // Git Bash for Windows paths are typically /<drive>/...
-        .replace(/^\/([a-zA-Z])(?:\/|$)/, (_, drive) => `${drive.toUpperCase()}:/`)
-        // Cygwin git paths are typically /cygdrive/<drive>/...
-        .replace(/^\/cygdrive\/([a-zA-Z])(?:\/|$)/, (_, drive) => `${drive.toUpperCase()}:/`)
-        // WSL paths are typically /mnt/<drive>/...
-        .replace(/^\/mnt\/([a-zA-Z])(?:\/|$)/, (_, drive) => `${drive.toUpperCase()}:/`)
-    )
-  }
-  export function overlaps(a: string, b: string) {
-    const relA = relative(a, b)
-    const relB = relative(b, a)
-    return !relA || !relA.startsWith("..") || !relB || !relB.startsWith("..")
-  }
-
-  export function contains(parent: string, child: string) {
-    return !relative(parent, child).startsWith("..")
-  }
-
   export async function findUp(target: string, start: string, stop?: string) {
-    let current = start
     const result = []
-    while (true) {
-      const search = join(current, target)
-      if (await exists(search)) result.push(search)
-      if (stop === current) break
-      const parent = dirname(current)
-      if (parent === current) break
-      current = parent
-    }
+    for await (const file of searchUp([target], start, stop)) result.push(file)
     return result
   }
 
   export async function* up(options: { targets: string[]; start: string; stop?: string }) {
-    const { targets, start, stop } = options
-    let current = start
-    while (true) {
-      for (const target of targets) {
-        const search = join(current, target)
-        if (await exists(search)) yield search
-      }
-      if (stop === current) break
-      const parent = dirname(current)
-      if (parent === current) break
-      current = parent
-    }
+    yield* searchUp(options.targets, options.start, options.stop)
   }
 
   export async function globUp(pattern: string, start: string, stop?: string) {
-    let current = start
     const result = []
-    while (true) {
+    for (const dir of Path.up(start, { stop })) {
       try {
         const matches = await Glob.scan(pattern, {
-          cwd: current,
+          cwd: dir,
           absolute: true,
           include: "file",
           dot: true,
@@ -193,10 +132,6 @@ export namespace Filesystem {
       } catch {
         // Skip invalid glob patterns
       }
-      if (stop === current) break
-      const parent = dirname(current)
-      if (parent === current) break
-      current = parent
     }
     return result
   }
diff --git a/packages/opencode/src/util/schema.ts b/packages/opencode/src/util/schema.ts
index 6a88dba539b5..ebd912f182dc 100644
--- a/packages/opencode/src/util/schema.ts
+++ b/packages/opencode/src/util/schema.ts
@@ -1,4 +1,5 @@
 import { Schema } from "effect"
+import z from "zod"
 
 /**
  * Attach static methods to a schema object. Designed to be used with `.pipe()`:
@@ -16,6 +17,39 @@ export const withStatics =
   (schema: S): S & M =>
     Object.assign(schema, methods(schema))
 
+function issue(ctx: z.core.$RefinementCtx<unknown>, err: unknown) {
+  ctx.addIssue({
+    code: z.ZodIssueCode.custom,
+    message: err instanceof Error ? err.message : String(err),
+  })
+}
+
+export function zodFrom<T>(parse: (input: string) => T): z.ZodType<T> {
+  return z.string().transform((input, ctx) => {
+    try {
+      return parse(input)
+    } catch (err) {
+      issue(ctx, err)
+      return z.NEVER
+    }
+  })
+}
+
+export function zodString<T extends string>(parse: (input: string) => T) {
+  const input = z.string().superRefine((value, ctx) => {
+    try {
+      parse(value)
+    } catch (err) {
+      issue(ctx, err)
+    }
+  })
+
+  return {
+    input,
+    zod: input as unknown as z.ZodType<T>,
+  }
+}
+
 declare const NewtypeBrand: unique symbol
 type NewtypeBrand<Tag extends string> = { readonly [NewtypeBrand]: Tag }
 
diff --git a/packages/opencode/src/worktree/index.ts b/packages/opencode/src/worktree/index.ts
index 6ed0e4820241..0f827dde20e0 100644
--- a/packages/opencode/src/worktree/index.ts
+++ b/packages/opencode/src/worktree/index.ts
@@ -15,6 +15,8 @@ import { Process } from "../util/process"
 import { git } from "../util/git"
 import { BusEvent } from "@/bus/bus-event"
 import { GlobalBus } from "@/bus/global"
+import { Path } from "@/path/path"
+import { PrettyPath } from "@/path/schema"
 
 export namespace Worktree {
   const log = Log.create({ service: "worktree" })
@@ -39,7 +41,7 @@ export namespace Worktree {
     .object({
       name: z.string(),
       branch: z.string(),
-      directory: z.string(),
+      directory: PrettyPath.zod,
     })
     .meta({
       ref: "Worktree",
@@ -237,19 +239,48 @@ export namespace Worktree {
     )
   }
 
-  async function prune(root: string, entries: string[]) {
-    const base = await canonical(root)
+  type Entry = {
+    path: PrettyPath
+    branch?: string
+  }
+
+  function entries(stdout: Uint8Array | undefined) {
+    return outputText(stdout)
+      .split("\n")
+      .map((line) => line.trim())
+      .reduce<Entry[]>((acc, line) => {
+        if (!line) return acc
+        if (line.startsWith("worktree ")) {
+          acc.push({ path: Path.from(line.slice("worktree ".length).trim(), { label: "git worktree path" }) })
+          return acc
+        }
+        const item = acc[acc.length - 1]
+        if (!item) return acc
+        if (line.startsWith("branch ")) item.branch = line.slice("branch ".length).trim()
+        return acc
+      }, [])
+  }
+
+  async function locate(stdout: Uint8Array | undefined, target: PrettyPath) {
+    const key = await Path.physicalKey(target)
+    for (const item of entries(stdout)) {
+      if ((await Path.physicalKey(item.path)) === key) return item
+    }
+  }
+
+  async function prune(root: PrettyPath, entries: string[]) {
+    const base = await Path.physical(root)
     await Promise.all(
       entries.map(async (entry) => {
-        const target = await canonical(path.resolve(root, entry))
-        if (target === base) return
-        if (!target.startsWith(`${base}${path.sep}`)) return
+        const target = await Path.physical(Path.join(root, entry))
+        if (Path.eq(target, base)) return
+        if (!Path.contains(base, target)) return
         await fs.rm(target, { recursive: true, force: true }).catch(() => undefined)
       }),
     )
   }
 
-  async function sweep(root: string) {
+  async function sweep(root: PrettyPath) {
     const first = await git(["clean", "-ffdx"], { cwd: root })
     if (first.exitCode === 0) return first
 
@@ -260,18 +291,11 @@ export namespace Worktree {
     return git(["clean", "-ffdx"], { cwd: root })
   }
 
-  async function canonical(input: string) {
-    const abs = path.resolve(input)
-    const real = await fs.realpath(abs).catch(() => abs)
-    const normalized = path.normalize(real)
-    return process.platform === "win32" ? normalized.toLowerCase() : normalized
-  }
-
-  async function candidate(root: string, base?: string) {
+  async function candidate(root: PrettyPath, base?: string) {
     for (const attempt of Array.from({ length: 26 }, (_, i) => i)) {
       const name = base ? (attempt === 0 ? base : `${base}-${randomName()}`) : randomName()
       const branch = `opencode/${name}`
-      const directory = path.join(root, name)
+      const directory = Path.join(root, name)
 
       if (await exists(directory)) continue
 
@@ -281,7 +305,7 @@ export namespace Worktree {
       })
       if (branchCheck.exitCode === 0) continue
 
-      return Info.parse({ name, branch, directory })
+      return { name, branch, directory }
     }
 
     throw new NameGenerationFailedError({ message: "Failed to generate a unique worktree name" })
@@ -340,7 +364,7 @@ export namespace Worktree {
       throw new NotGitError({ message: "Worktrees are only supported for git projects" })
     }
 
-    const root = path.join(Global.Path.data, "worktree", Instance.project.id)
+    const root = Path.join(Global.Path.data, path.join("worktree", Instance.project.id))
     await fs.mkdir(root, { recursive: true })
 
     const base = name ? slug(name) : ""
@@ -436,35 +460,10 @@ export namespace Worktree {
       throw new NotGitError({ message: "Worktrees are only supported for git projects" })
     }
 
-    const directory = await canonical(input.directory)
-    const locate = async (stdout: Uint8Array | undefined) => {
-      const lines = outputText(stdout)
-        .split("\n")
-        .map((line) => line.trim())
-      const entries = lines.reduce<{ path?: string; branch?: string }[]>((acc, line) => {
-        if (!line) return acc
-        if (line.startsWith("worktree ")) {
-          acc.push({ path: line.slice("worktree ".length).trim() })
-          return acc
-        }
-        const current = acc[acc.length - 1]
-        if (!current) return acc
-        if (line.startsWith("branch ")) {
-          current.branch = line.slice("branch ".length).trim()
-        }
-        return acc
-      }, [])
-
-      return (async () => {
-        for (const item of entries) {
-          if (!item.path) continue
-          const key = await canonical(item.path)
-          if (key === directory) return item
-        }
-      })()
-    }
+    const directory = Path.from(input.directory, { label: "worktree directory" })
+    const target = await Path.physical(directory)
 
-    const clean = (target: string) =>
+    const clean = (target: PrettyPath) =>
       fs
         .rm(target, {
           recursive: true,
@@ -477,7 +476,7 @@ export namespace Worktree {
           throw new RemoveFailedError({ message: message || "Failed to remove git worktree directory" })
         })
 
-    const stop = async (target: string) => {
+    const stop = async (target: PrettyPath) => {
       if (!(await exists(target))) return
       await git(["fsmonitor--daemon", "stop"], { cwd: target })
     }
@@ -487,13 +486,13 @@ export namespace Worktree {
       throw new RemoveFailedError({ message: errorText(list) || "Failed to read git worktrees" })
     }
 
-    const entry = await locate(list.stdout)
+    const entry = await locate(list.stdout, target)
 
-    if (!entry?.path) {
-      const directoryExists = await exists(directory)
+    if (!entry) {
+      const directoryExists = await exists(target)
       if (directoryExists) {
-        await stop(directory)
-        await clean(directory)
+        await stop(target)
+        await clean(target)
       }
       return true
     }
@@ -510,8 +509,8 @@ export namespace Worktree {
         })
       }
 
-      const stale = await locate(next.stdout)
-      if (stale?.path) {
+      const stale = await locate(next.stdout, target)
+      if (stale) {
         throw new RemoveFailedError({ message: errorText(removed) || "Failed to remove git worktree" })
       }
     }
@@ -534,9 +533,10 @@ export namespace Worktree {
       throw new NotGitError({ message: "Worktrees are only supported for git projects" })
     }
 
-    const directory = await canonical(input.directory)
-    const primary = await canonical(Instance.worktree)
-    if (directory === primary) {
+    const directory = Path.from(input.directory, { label: "worktree directory" })
+    const targetKey = await Path.physicalKey(directory)
+    const primary = await Path.physicalKey(Instance.worktree)
+    if (targetKey === primary) {
       throw new ResetFailedError({ message: "Cannot reset the primary workspace" })
     }
 
@@ -545,31 +545,8 @@ export namespace Worktree {
       throw new ResetFailedError({ message: errorText(list) || "Failed to read git worktrees" })
     }
 
-    const lines = outputText(list.stdout)
-      .split("\n")
-      .map((line) => line.trim())
-    const entries = lines.reduce<{ path?: string; branch?: string }[]>((acc, line) => {
-      if (!line) return acc
-      if (line.startsWith("worktree ")) {
-        acc.push({ path: line.slice("worktree ".length).trim() })
-        return acc
-      }
-      const current = acc[acc.length - 1]
-      if (!current) return acc
-      if (line.startsWith("branch ")) {
-        current.branch = line.slice("branch ".length).trim()
-      }
-      return acc
-    }, [])
-
-    const entry = await (async () => {
-      for (const item of entries) {
-        if (!item.path) continue
-        const key = await canonical(item.path)
-        if (key === directory) return item
-      }
-    })()
-    if (!entry?.path) {
+    const entry = await locate(list.stdout, directory)
+    if (!entry) {
       throw new ResetFailedError({ message: "Worktree not found" })
     }
 
@@ -619,10 +596,6 @@ export namespace Worktree {
       }
     }
 
-    if (!entry.path) {
-      throw new ResetFailedError({ message: "Worktree path not found" })
-    }
-
     const worktreePath = entry.path
 
     const resetToTarget = await git(["reset", "--hard", target], { cwd: worktreePath })
diff --git a/packages/opencode/test/acp/prompt-file-uri.test.ts b/packages/opencode/test/acp/prompt-file-uri.test.ts
new file mode 100644
index 000000000000..842fcf87acec
--- /dev/null
+++ b/packages/opencode/test/acp/prompt-file-uri.test.ts
@@ -0,0 +1,169 @@
+import { describe, expect, test } from "bun:test"
+import type { AgentSideConnection } from "@agentclientprotocol/sdk"
+import { pathToFileURL } from "url"
+
+import { ACP } from "../../src/acp/agent"
+import { Instance } from "../../src/project/instance"
+import { tmpdir } from "../fixture/fixture"
+
+function createStream() {
+  const wait: Array<() => void> = []
+
+  return {
+    stream: async function* (signal?: AbortSignal) {
+      await new Promise<void>((resolve) => {
+        if (signal?.aborted) return resolve()
+        wait.push(resolve)
+        signal?.addEventListener("abort", () => resolve(), { once: true })
+      })
+    },
+    close: () => {
+      for (const resolve of wait.splice(0)) resolve()
+    },
+  }
+}
+
+function createAgent() {
+  const seen: any[] = []
+  const connection = {
+    async sessionUpdate() {},
+    async requestPermission() {
+      return { outcome: { outcome: "selected", optionId: "once" } }
+    },
+  } as unknown as AgentSideConnection
+
+  const events = createStream()
+  const sdk = {
+    global: {
+      event: async (opts?: { signal?: AbortSignal }) => ({
+        stream: events.stream(opts?.signal),
+      }),
+    },
+    session: {
+      create: async () => ({
+        data: {
+          id: "ses_1",
+          time: { created: new Date().toISOString() },
+        },
+      }),
+      messages: async () => ({ data: [] }),
+      prompt: async (input: any) => {
+        seen.push(input)
+        return { data: {} }
+      },
+    },
+    config: {
+      providers: async () => ({
+        data: {
+          providers: [
+            {
+              id: "opencode",
+              name: "opencode",
+              models: {
+                "big-pickle": { id: "big-pickle", name: "big-pickle" },
+              },
+            },
+          ],
+        },
+      }),
+    },
+    app: {
+      agents: async () => ({
+        data: [
+          {
+            name: "build",
+            description: "build",
+            mode: "agent",
+          },
+        ],
+      }),
+    },
+    command: {
+      list: async () => ({ data: [] }),
+    },
+    mcp: {
+      add: async () => ({ data: true }),
+    },
+  } as any
+
+  const agent = new ACP.Agent(connection, {
+    sdk,
+    defaultModel: { providerID: "opencode", modelID: "big-pickle" },
+  } as any)
+
+  return {
+    agent,
+    seen,
+    stop: () => {
+      events.close()
+      ;(agent as any).eventAbort.abort()
+    },
+  }
+}
+
+describe("acp.agent prompt file uris", () => {
+  test("parses Windows file resource links with fileURLToPath", async () => {
+    if (process.platform !== "win32") return
+
+    await using tmp = await tmpdir()
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const { agent, seen, stop } = createAgent()
+        try {
+          const cwd = tmp.path
+          const sessionId = await agent.newSession({ cwd, mcpServers: [] } as any).then((x) => x.sessionId)
+
+          await agent.prompt({
+            sessionId,
+            prompt: [{ type: "resource_link", uri: "file:///C:/Users/me/My%20Docs/hello%20world.txt" }],
+          } as any)
+
+          expect(seen[0].parts).toEqual([
+            {
+              type: "file",
+              url: "file:///C:/Users/me/My%20Docs/hello%20world.txt",
+              filename: "hello world.txt",
+              mime: "text/plain",
+            },
+          ])
+        } finally {
+          stop()
+        }
+      },
+    })
+  })
+
+  test("keeps zed resource links mapped to local file URLs on Windows", async () => {
+    if (process.platform !== "win32") return
+
+    await using tmp = await tmpdir()
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const { agent, seen, stop } = createAgent()
+        try {
+          const cwd = tmp.path
+          const sessionId = await agent.newSession({ cwd, mcpServers: [] } as any).then((x) => x.sessionId)
+          const file = "C:\\Users\\me\\My Docs\\hello world.txt"
+
+          await agent.prompt({
+            sessionId,
+            prompt: [{ type: "resource_link", uri: `zed://file?path=${encodeURIComponent(file)}` }],
+          } as any)
+
+          expect(seen[0].parts).toEqual([
+            {
+              type: "file",
+              url: pathToFileURL(file).href,
+              filename: "hello world.txt",
+              mime: "text/plain",
+            },
+          ])
+        } finally {
+          stop()
+        }
+      },
+    })
+  })
+})
diff --git a/packages/opencode/test/agent/agent.test.ts b/packages/opencode/test/agent/agent.test.ts
index 2805cf2614e1..39b94b4e85bc 100644
--- a/packages/opencode/test/agent/agent.test.ts
+++ b/packages/opencode/test/agent/agent.test.ts
@@ -3,6 +3,8 @@ import path from "path"
 import { tmpdir } from "../fixture/fixture"
 import { Instance } from "../../src/project/instance"
 import { Agent } from "../../src/agent/agent"
+import { Global } from "../../src/global"
+import { Path } from "../../src/path/path"
 import { Permission } from "../../src/permission"
 
 // Helper to evaluate permission for a tool with wildcard pattern
@@ -59,6 +61,13 @@ test("plan agent denies edits except .opencode/plans/*", async () => {
       expect(evalPerm(plan, "edit")).toBe("deny")
       // But specific path is allowed
       expect(Permission.evaluate("edit", ".opencode/plans/foo.md", plan!.permission).action).toBe("allow")
+      expect(
+        Permission.evaluate(
+          "edit",
+          String(Path.rel(Instance.worktree, path.join(Global.Path.data, "plans", "foo.md"))),
+          plan!.permission,
+        ).action,
+      ).toBe("allow")
     },
   })
 })
diff --git a/packages/opencode/test/cli/dir.test.ts b/packages/opencode/test/cli/dir.test.ts
new file mode 100644
index 000000000000..9fb309e6c953
--- /dev/null
+++ b/packages/opencode/test/cli/dir.test.ts
@@ -0,0 +1,67 @@
+import { describe, expect, test } from "bun:test"
+import fs from "fs/promises"
+import path from "path"
+import { dir } from "../../src/cli/cmd/dir"
+import { Path } from "../../src/path/path"
+import { tmpdir } from "../fixture/fixture"
+
+describe("cli dir", () => {
+  test("resolves relative dirs from the logical cwd", async () => {
+    await using tmp = await tmpdir()
+    const link = path.join(path.dirname(tmp.path), path.basename(tmp.path) + "-link")
+    const type = process.platform === "win32" ? "junction" : "dir"
+    await fs.mkdir(path.join(tmp.path, "child"))
+    await fs.symlink(tmp.path, link, type)
+
+    try {
+      expect(dir("child", { cwd: link })).toBe(path.join(link, "child"))
+    } finally {
+      await fs.rm(link, { recursive: true, force: true }).catch(() => undefined)
+    }
+  })
+
+  test("keeps remote relative dirs raw", () => {
+    expect(dir("remote/app", { cwd: "/tmp/root", remote: true })).toBe("remote/app")
+  })
+
+  test("normalizes remote file uris", async () => {
+    await using tmp = await tmpdir()
+    const child = path.join(tmp.path, "child")
+    await fs.mkdir(child)
+
+    expect(dir(String(Path.uri(child)), { remote: true })).toBe(child)
+  })
+
+  test("normalizes remote UNC file uris without using the local os", () => {
+    expect(dir("file://server/share/code/../repo", { remote: true })).toBe("\\\\server\\share\\repo")
+  })
+
+  test("treats localhost remote file uris as local roots", () => {
+    expect(dir("file://localhost/C:/Users/me/code/../repo", { remote: true })).toBe("C:\\Users\\me\\repo")
+    expect(dir("file://localhost/srv/code/../repo", { remote: true })).toBe("/srv/repo")
+  })
+
+  test("preserves undecodable segments in remote file uris", () => {
+    expect(dir("file:///tmp/%ZZ/repo", { remote: true })).toBe("/tmp/%ZZ/repo")
+  })
+
+  test("normalizes remote windows absolute paths without using the local os", () => {
+    expect(dir("/C:/Users/me/code/../repo", { remote: true })).toBe("C:\\Users\\me\\repo")
+  })
+
+  test("normalizes remote native windows absolute paths without using the local os", () => {
+    expect(dir("C:\\Users\\me\\code\\..\\repo", { remote: true })).toBe("C:\\Users\\me\\repo")
+  })
+
+  test("normalizes remote windows drive roots without using the local os", () => {
+    expect(dir("/C:", { remote: true })).toBe("C:\\")
+  })
+
+  test("normalizes remote UNC backslash paths without using the local os", () => {
+    expect(dir("\\\\server\\share\\code\\..\\repo", { remote: true })).toBe("\\\\server\\share\\repo")
+  })
+
+  test("preserves remote posix absolute paths without using the local os", () => {
+    expect(dir("/srv/code/../repo", { remote: true })).toBe("/srv/repo")
+  })
+})
diff --git a/packages/opencode/test/cli/tui/attach.test.ts b/packages/opencode/test/cli/tui/attach.test.ts
new file mode 100644
index 000000000000..093b1316a49d
--- /dev/null
+++ b/packages/opencode/test/cli/tui/attach.test.ts
@@ -0,0 +1,153 @@
+import { beforeEach, describe, expect, mock, test } from "bun:test"
+import fs from "fs/promises"
+import path from "path"
+import { Path } from "../../../src/path/path"
+import { tmpdir } from "../../fixture/fixture"
+
+const seen = {
+  tui: [] as (string | undefined)[],
+  inst: [] as string[],
+}
+
+mock.module("../../../src/cli/cmd/tui/app", () => ({
+  tui: async (input: { directory?: string }) => {
+    seen.tui.push(input.directory)
+  },
+}))
+
+mock.module("@/config/tui", () => ({
+  TuiConfig: {
+    get: () => ({}),
+  },
+}))
+
+mock.module("@/project/instance", () => ({
+  Instance: {
+    provide: async (input: { directory: string; fn: () => Promise<unknown> | unknown }) => {
+      seen.inst.push(input.directory)
+      return input.fn()
+    },
+  },
+}))
+
+mock.module("../../../src/cli/cmd/tui/win32", () => ({
+  win32DisableProcessedInput: () => {},
+  win32InstallCtrlCGuard: () => undefined,
+}))
+
+mock.module("@/cli/ui", () => ({
+  UI: {
+    error: () => {},
+  },
+}))
+
+describe("tui attach", () => {
+  beforeEach(() => {
+    seen.tui.length = 0
+    seen.inst.length = 0
+  })
+
+  async function call(dir?: string, url = "http://localhost:4096") {
+    const { AttachCommand } = await import("../../../src/cli/cmd/tui/attach")
+    const args: Parameters<NonNullable<typeof AttachCommand.handler>>[0] = {
+      _: [],
+      $0: "opencode",
+      url,
+      dir,
+      continue: false,
+      session: undefined,
+      fork: false,
+      password: undefined,
+    }
+    return AttachCommand.handler(args)
+  }
+
+  test("normalizes local file uri directories", async () => {
+    await using tmp = await tmpdir()
+    const cwd = process.cwd()
+    const child = path.join(tmp.path, "child")
+    await fs.mkdir(child)
+
+    try {
+      await call(String(Path.uri(child)))
+      expect(seen.inst[0]).toBe(child)
+      expect(seen.tui[0]).toBe(child)
+    } finally {
+      process.chdir(cwd)
+    }
+  })
+
+  test("keeps remote relative directories raw", async () => {
+    await using tmp = await tmpdir()
+    const cwd = process.cwd()
+    const pwd = process.env.PWD
+
+    try {
+      process.chdir(tmp.path)
+      process.env.PWD = tmp.path
+      await call("remote/app")
+      expect(seen.inst[0]).toBe(tmp.path)
+      expect(seen.tui[0]).toBe("remote/app")
+    } finally {
+      process.chdir(cwd)
+      if (pwd === undefined) delete process.env.PWD
+      else process.env.PWD = pwd
+    }
+  })
+
+  test("keeps remote absolute directories off the local filesystem", async () => {
+    await using tmp = await tmpdir()
+    const cwd = process.cwd()
+    const pwd = process.env.PWD
+    const child = path.join(tmp.path, "child")
+
+    try {
+      await fs.mkdir(child)
+      process.chdir(tmp.path)
+      process.env.PWD = tmp.path
+      await call(child, "http://10.0.0.8:4096")
+      expect(seen.inst[0]).toBe(tmp.path)
+      expect(seen.tui[0]).toBe(child)
+    } finally {
+      process.chdir(cwd)
+      if (pwd === undefined) delete process.env.PWD
+      else process.env.PWD = pwd
+    }
+  })
+
+  test("passes remote UNC directories through without using them for the local instance", async () => {
+    await using tmp = await tmpdir()
+    const cwd = process.cwd()
+    const pwd = process.env.PWD
+
+    try {
+      process.chdir(tmp.path)
+      process.env.PWD = tmp.path
+      await call("file://server/share/code/../repo", "http://10.0.0.8:4096")
+      expect(seen.inst[0]).toBe(tmp.path)
+      expect(seen.tui[0]).toBe("\\\\server\\share\\repo")
+    } finally {
+      process.chdir(cwd)
+      if (pwd === undefined) delete process.env.PWD
+      else process.env.PWD = pwd
+    }
+  })
+
+  test("preserves undecodable remote file URI segments across the attach boundary", async () => {
+    await using tmp = await tmpdir()
+    const cwd = process.cwd()
+    const pwd = process.env.PWD
+
+    try {
+      process.chdir(tmp.path)
+      process.env.PWD = tmp.path
+      await call("file:///tmp/%ZZ/repo", "http://10.0.0.8:4096")
+      expect(seen.inst[0]).toBe(tmp.path)
+      expect(seen.tui[0]).toBe("/tmp/%ZZ/repo")
+    } finally {
+      process.chdir(cwd)
+      if (pwd === undefined) delete process.env.PWD
+      else process.env.PWD = pwd
+    }
+  })
+})
diff --git a/packages/opencode/test/cli/tui/path.test.ts b/packages/opencode/test/cli/tui/path.test.ts
new file mode 100644
index 000000000000..9b7f7474ef97
--- /dev/null
+++ b/packages/opencode/test/cli/tui/path.test.ts
@@ -0,0 +1,87 @@
+import { describe, expect, test } from "bun:test"
+import { formatPath, formatServerPath, plugin, serverPathKey, splitPath } from "../../../src/cli/cmd/tui/util/path"
+
+describe("tui path", () => {
+  test("formats Windows absolute paths without a leading slash", () => {
+    expect(
+      formatPath("/C:/Users/me/code/opencode", {
+        platform: "win32",
+      }),
+    ).toBe("C:\\Users\\me\\code\\opencode")
+  })
+
+  test("keeps cwd-relative paths relative before shortening home", () => {
+    expect(
+      formatPath("C:\\Users\\me\\code\\opencode\\src\\file.ts", {
+        cwd: "C:\\Users\\me\\code\\opencode",
+        home: "C:\\Users\\me",
+        platform: "win32",
+        relative: true,
+      }),
+    ).toBe("src\\file.ts")
+  })
+
+  test("formats server-relative paths without local cwd fallback", () => {
+    expect(
+      formatServerPath("src/file.ts", {
+        os: "linux",
+      }),
+    ).toBe("src/file.ts")
+
+    expect(
+      formatServerPath("src/file.ts", {
+        directory: "C:\\Users\\me\\code\\opencode",
+        home: "C:\\Users\\me",
+        os: "windows",
+      }, { relative: true }),
+    ).toBe("src\\file.ts")
+  })
+
+  test("keys server paths with server cwd semantics", () => {
+    expect(
+      serverPathKey("src\\FILE.ts", {
+        directory: "C:\\Users\\me\\code\\opencode",
+        os: "windows",
+      }),
+    ).toBe("c:\\users\\me\\code\\opencode\\src\\file.ts")
+
+    expect(
+      serverPathKey("src\\FILE.ts", {
+        os: "windows",
+      }),
+    ).toBe("src/file.ts")
+  })
+
+  test("shortens home with directory boundaries", () => {
+    expect(
+      formatPath("C:\\Users\\me\\code\\opencode", {
+        home: "C:\\Users\\me",
+        platform: "win32",
+      }),
+    ).toBe("~\\code\\opencode")
+
+    expect(
+      formatPath("C:\\Users\\meow\\code\\opencode", {
+        home: "C:\\Users\\me",
+        platform: "win32",
+      }),
+    ).toBe("C:\\Users\\meow\\code\\opencode")
+  })
+
+  test("splits display paths with native separators", () => {
+    expect(splitPath("C:\\Users\\me\\code\\opencode", { platform: "win32" })).toEqual({
+      dir: "C:\\Users\\me\\code\\",
+      base: "opencode",
+    })
+  })
+
+  test("extracts plugin names from file uris safely", () => {
+    expect(plugin("file:///C:/Users/me/.config/opencode/plugins/demo/index.ts", { platform: "win32" })).toEqual({
+      name: "demo",
+    })
+
+    expect(plugin("file:///C:/Users/me/.config/opencode/plugins/local.ts", { platform: "win32" })).toEqual({
+      name: "local",
+    })
+  })
+})
diff --git a/packages/opencode/test/cli/tui/thread.test.ts b/packages/opencode/test/cli/tui/thread.test.ts
index d3de7c3183d3..05b3a18f68f1 100644
--- a/packages/opencode/test/cli/tui/thread.test.ts
+++ b/packages/opencode/test/cli/tui/thread.test.ts
@@ -134,8 +134,8 @@ describe("tui thread", () => {
       process.chdir(tmp.path)
       process.env.PWD = link
       await expect(call(project)).rejects.toBe(stop)
-      expect(seen.inst[0]).toBe(tmp.path)
-      expect(seen.tui[0]).toBe(tmp.path)
+      expect(seen.inst[0]).toBe(link)
+      expect(seen.tui[0]).toBe(link)
     } finally {
       process.chdir(cwd)
       if (pwd === undefined) delete process.env.PWD
@@ -147,11 +147,11 @@ describe("tui thread", () => {
     }
   }
 
-  test("uses the real cwd when PWD points at a symlink", async () => {
+  test("keeps the logical PWD when it points at a symlink", async () => {
     await check()
   })
 
-  test("uses the real cwd after resolving a relative project from PWD", async () => {
+  test("keeps the logical PWD when resolving a relative project", async () => {
     await check(".")
   })
 })
diff --git a/packages/opencode/test/cli/tui/transcript.test.ts b/packages/opencode/test/cli/tui/transcript.test.ts
index 7a5fa6b8f1cf..958bd2c3a649 100644
--- a/packages/opencode/test/cli/tui/transcript.test.ts
+++ b/packages/opencode/test/cli/tui/transcript.test.ts
@@ -1,4 +1,5 @@
 import { describe, expect, test } from "bun:test"
+import { Path } from "../../../src/path/path"
 import {
   formatAssistantHeader,
   formatMessage,
@@ -18,7 +19,7 @@ describe("transcript", () => {
       providerID: "anthropic",
       mode: "",
       parentID: "msg_parent",
-      path: { cwd: "/test", root: "/test" },
+      path: { cwd: Path.pretty("/test"), root: Path.pretty("/test") },
       cost: 0.001,
       tokens: { input: 100, output: 50, reasoning: 0, cache: { read: 0, write: 0 } },
       time: { created: 1000000, completed: 1005400 },
@@ -223,7 +224,7 @@ describe("transcript", () => {
         providerID: "anthropic",
         mode: "",
         parentID: "msg_parent",
-        path: { cwd: "/test", root: "/test" },
+        path: { cwd: Path.pretty("/test"), root: Path.pretty("/test") },
         cost: 0.001,
         tokens: { input: 100, output: 50, reasoning: 0, cache: { read: 0, write: 0 } },
         time: { created: 1000000, completed: 1005400 },
@@ -264,7 +265,7 @@ describe("transcript", () => {
             providerID: "anthropic",
             mode: "",
             parentID: "msg_1",
-            path: { cwd: "/test", root: "/test" },
+            path: { cwd: Path.pretty("/test"), root: Path.pretty("/test") },
             cost: 0.001,
             tokens: { input: 100, output: 50, reasoning: 0, cache: { read: 0, write: 0 } },
             time: { created: 1000000000100, completed: 1000000000600 },
@@ -302,7 +303,7 @@ describe("transcript", () => {
             providerID: "anthropic",
             mode: "",
             parentID: "msg_0",
-            path: { cwd: "/test", root: "/test" },
+            path: { cwd: Path.pretty("/test"), root: Path.pretty("/test") },
             cost: 0.001,
             tokens: { input: 100, output: 50, reasoning: 0, cache: { read: 0, write: 0 } },
             time: { created: 1000000000100, completed: 1000000000600 },
diff --git a/packages/opencode/test/config/config.test.ts b/packages/opencode/test/config/config.test.ts
index eb9c763fa757..bcf1b733a929 100644
--- a/packages/opencode/test/config/config.test.ts
+++ b/packages/opencode/test/config/config.test.ts
@@ -11,6 +11,8 @@ import { Global } from "../../src/global"
 import { ProjectID } from "../../src/project/schema"
 import { Filesystem } from "../../src/util/filesystem"
 import { BunProc } from "../../src/bun"
+import { Path } from "../../src/path/path"
+import { win as alias } from "../lib/windows-path"
 
 // Get managed config directory from environment (set in preload.ts)
 const managedConfigDir = process.env.OPENCODE_TEST_MANAGED_CONFIG_DIR!
@@ -45,7 +47,7 @@ async function check(map: (dir: string) => string) {
       fn: async () => {
         const cfg = await Config.get()
         expect(cfg.snapshot).toBe(true)
-        expect(Instance.directory).toBe(Filesystem.resolve(tmp.path))
+        expect(Instance.directory).toBe(Path.truecaseSync(tmp.path))
         expect(Instance.project.id).not.toBe(ProjectID.global)
       },
     })
@@ -329,6 +331,48 @@ test("handles file inclusion with replacement tokens", async () => {
   })
 })
 
+test("handles file inclusion via file URI reference", async () => {
+  await using tmp = await tmpdir({
+    init: async (dir) => {
+      const file = path.join(dir, "included.txt")
+      await Filesystem.write(file, "uri-user")
+      await writeConfig(dir, {
+        $schema: "https://opencode.ai/config.json",
+        username: `{file:${Path.uri(file)}}`,
+      })
+    },
+  })
+  await Instance.provide({
+    directory: tmp.path,
+    fn: async () => {
+      const config = await Config.get()
+      expect(config.username).toBe("uri-user")
+    },
+  })
+})
+
+test("handles file inclusion via Windows alias reference", async () => {
+  if (process.platform !== "win32") return
+
+  await using tmp = await tmpdir({
+    init: async (dir) => {
+      const file = path.join(dir, "included.txt")
+      await Filesystem.write(file, "alias-user")
+      await writeConfig(dir, {
+        $schema: "https://opencode.ai/config.json",
+        username: `{file:${alias(file).find((item) => item.name === "git")!.path}}`,
+      })
+    },
+  })
+  await Instance.provide({
+    directory: tmp.path,
+    fn: async () => {
+      const config = await Config.get()
+      expect(config.username).toBe("alias-user")
+    },
+  })
+})
+
 test("validates config schema and throws on invalid fields", async () => {
   await using tmp = await tmpdir({
     init: async (dir) => {
@@ -2075,4 +2119,32 @@ describe("OPENCODE_CONFIG_CONTENT token substitution", () => {
       }
     }
   })
+
+  test("substitutes {file:~/...} tokens in OPENCODE_CONFIG_CONTENT", async () => {
+    const originalEnv = process.env["OPENCODE_CONFIG_CONTENT"]
+    const home = process.env.OPENCODE_TEST_HOME!
+
+    try {
+      await Filesystem.write(path.join(home, "api_key.txt"), "secret_key_from_home")
+      process.env["OPENCODE_CONFIG_CONTENT"] = JSON.stringify({
+        $schema: "https://opencode.ai/config.json",
+        username: "{file:~/api_key.txt}",
+      })
+
+      await using tmp = await tmpdir()
+      await Instance.provide({
+        directory: tmp.path,
+        fn: async () => {
+          const config = await Config.get()
+          expect(config.username).toBe("secret_key_from_home")
+        },
+      })
+    } finally {
+      if (originalEnv !== undefined) {
+        process.env["OPENCODE_CONFIG_CONTENT"] = originalEnv
+      } else {
+        delete process.env["OPENCODE_CONFIG_CONTENT"]
+      }
+    }
+  })
 })
diff --git a/packages/opencode/test/control-plane/session-proxy-middleware.test.ts b/packages/opencode/test/control-plane/session-proxy-middleware.test.ts
index d4d152a1c6e9..8575bee44788 100644
--- a/packages/opencode/test/control-plane/session-proxy-middleware.test.ts
+++ b/packages/opencode/test/control-plane/session-proxy-middleware.test.ts
@@ -9,8 +9,9 @@ import { WorkspaceContext } from "../../src/control-plane/workspace-context"
 import { Database } from "../../src/storage/db"
 import { resetDatabase } from "../fixture/db"
 import * as adaptors from "../../src/control-plane/adaptors"
-import type { Adaptor } from "../../src/control-plane/types"
+import type { Adaptor, WorkspaceFetchInput } from "../../src/control-plane/types"
 import { Flag } from "../../src/flag/flag"
+import { PrettyPath } from "../../src/path/schema"
 
 afterEach(async () => {
   mock.restore()
@@ -43,7 +44,7 @@ async function setup(state: State) {
     },
     async remove() {},
 
-    async fetch(_config: unknown, input: RequestInfo | URL, init?: RequestInit) {
+    async fetch(_config: unknown, input: WorkspaceFetchInput, init?: RequestInit) {
       const url =
         input instanceof Request || input instanceof URL
           ? input.toString()
@@ -83,7 +84,7 @@ async function setup(state: State) {
           branch: "main",
           project_id: project.id,
           type: "worktree",
-          directory: tmp.path,
+          directory: PrettyPath.make(tmp.path),
           name: "local",
         },
       ])
diff --git a/packages/opencode/test/control-plane/workspace-server-sse.test.ts b/packages/opencode/test/control-plane/workspace-server-sse.test.ts
index 7e7cddb1404e..ad1d905faa1b 100644
--- a/packages/opencode/test/control-plane/workspace-server-sse.test.ts
+++ b/packages/opencode/test/control-plane/workspace-server-sse.test.ts
@@ -1,17 +1,33 @@
-import { afterEach, describe, expect, test } from "bun:test"
+import { afterEach, describe, expect, mock, spyOn, test } from "bun:test"
+import fs from "fs/promises"
+import path from "path"
 import { Log } from "../../src/util/log"
-import { WorkspaceServer } from "../../src/control-plane/workspace-server/server"
 import { parseSSE } from "../../src/control-plane/sse"
 import { GlobalBus } from "../../src/bus/global"
+import { Instance } from "../../src/project/instance"
 import { resetDatabase } from "../fixture/db"
 import { tmpdir } from "../fixture/fixture"
 
+mock.module("../../src/project/bootstrap", () => ({
+  InstanceBootstrap: async () => {},
+}))
+
+const { WorkspaceServer } = await import("../../src/control-plane/workspace-server/server")
+
 afterEach(async () => {
+  await Instance.disposeAll()
   await resetDatabase()
 })
 
 Log.init({ print: false })
 
+async function link(dir: string) {
+  const alias = path.join(path.dirname(dir), path.basename(dir) + "-link")
+  await fs.rm(alias, { recursive: true, force: true }).catch(() => undefined)
+  await fs.symlink(dir, alias, process.platform === "win32" ? "junction" : "dir")
+  return alias
+}
+
 describe("control-plane/workspace-server SSE", () => {
   test("streams GlobalBus events and parseSSE reads them", async () => {
     await using tmp = await tmpdir({ git: true })
@@ -67,4 +83,108 @@ describe("control-plane/workspace-server SSE", () => {
       stop.abort()
     }
   })
+
+  test("keeps alias directories before Instance.provide", async () => {
+    await using tmp = await tmpdir({ git: true })
+    const alias = await link(tmp.path)
+    const app = WorkspaceServer.App()
+    const stop = new AbortController()
+    const provide = Instance.provide
+    const spy = spyOn(Instance, "provide").mockImplementation((input) => provide(input))
+
+    try {
+      const response = await app.request("/event", {
+        signal: stop.signal,
+        headers: {
+          "x-opencode-workspace": "wrk_test_workspace",
+          "x-opencode-directory": `${alias}${path.sep}work${path.sep}..`,
+        },
+      })
+
+      expect(response.status).toBe(200)
+      expect(spy.mock.calls[0]?.[0]?.directory).toBe(alias)
+    } finally {
+      stop.abort()
+      spy.mockRestore()
+      await fs.rm(alias, { recursive: true, force: true }).catch(() => undefined)
+    }
+  })
+
+  test("accepts literal percent directories before Instance.provide", async () => {
+    await using tmp = await tmpdir({ git: true })
+    const dir = path.join(tmp.path, "100% ready")
+    await fs.mkdir(dir)
+    const app = WorkspaceServer.App()
+    const stop = new AbortController()
+    const provide = Instance.provide
+    const spy = spyOn(Instance, "provide").mockImplementation((input) => provide(input))
+
+    try {
+      const response = await app.request("/event", {
+        signal: stop.signal,
+        headers: {
+          "x-opencode-workspace": "wrk_test_workspace",
+          "x-opencode-directory": dir,
+        },
+      })
+
+      expect(response.status).toBe(200)
+      expect(spy.mock.calls[0]?.[0]?.directory).toBe(dir)
+    } finally {
+      stop.abort()
+      spy.mockRestore()
+    }
+  })
+
+  test("decodes encoded directory headers before Instance.provide", async () => {
+    await using tmp = await tmpdir({ git: true })
+    const dir = path.join(tmp.path, "100% ready")
+    await fs.mkdir(dir)
+    const app = WorkspaceServer.App()
+    const stop = new AbortController()
+    const provide = Instance.provide
+    const spy = spyOn(Instance, "provide").mockImplementation((input) => provide(input))
+
+    try {
+      const response = await app.request("/event", {
+        signal: stop.signal,
+        headers: {
+          "x-opencode-workspace": "wrk_test_workspace",
+          "x-opencode-directory": encodeURIComponent(dir),
+        },
+      })
+
+      expect(response.status).toBe(200)
+      expect(spy.mock.calls[0]?.[0]?.directory).toBe(dir)
+    } finally {
+      stop.abort()
+      spy.mockRestore()
+    }
+  })
+
+  test("rejects invalid workspace ids before bootstrapping", async () => {
+    const app = WorkspaceServer.App()
+    const response = await app.request("/event", {
+      headers: {
+        "x-opencode-workspace": "workspace_test_workspace",
+        "x-opencode-directory": process.cwd(),
+      },
+    })
+
+    expect(response.status).toBe(400)
+    expect(await response.text()).toContain('Expected workspace id starting with "wrk"')
+  })
+
+  test("rejects invalid encoded directories before bootstrapping", async () => {
+    const app = WorkspaceServer.App()
+    const response = await app.request("/event", {
+      headers: {
+        "x-opencode-workspace": "wrk_test_workspace",
+        "x-opencode-directory": "%E0%A4%A",
+      },
+    })
+
+    expect(response.status).toBe(400)
+    expect(await response.text()).toContain("Invalid percent-encoding in directory parameter")
+  })
 })
diff --git a/packages/opencode/test/control-plane/workspace-sync.test.ts b/packages/opencode/test/control-plane/workspace-sync.test.ts
index 0f8d608fb39b..b17289b25dbc 100644
--- a/packages/opencode/test/control-plane/workspace-sync.test.ts
+++ b/packages/opencode/test/control-plane/workspace-sync.test.ts
@@ -8,7 +8,8 @@ import { WorkspaceTable } from "../../src/control-plane/workspace.sql"
 import { GlobalBus } from "../../src/bus/global"
 import { resetDatabase } from "../fixture/db"
 import * as adaptors from "../../src/control-plane/adaptors"
-import type { Adaptor } from "../../src/control-plane/types"
+import type { Adaptor, WorkspaceFetchInput } from "../../src/control-plane/types"
+import { PrettyPath } from "../../src/path/schema"
 
 afterEach(async () => {
   mock.restore()
@@ -27,7 +28,7 @@ const TestAdaptor: Adaptor = {
     throw new Error("not used")
   },
   async remove() {},
-  async fetch(_config: unknown, _input: RequestInfo | URL, _init?: RequestInit) {
+  async fetch(_config: unknown, _input: WorkspaceFetchInput, _init?: RequestInit) {
     const body = new ReadableStream<Uint8Array>({
       start(controller) {
         const encoder = new TextEncoder()
@@ -71,7 +72,7 @@ describe("control-plane/workspace.startSyncing", () => {
             branch: "main",
             project_id: project.id,
             type: "worktree",
-            directory: tmp.path,
+            directory: PrettyPath.make(tmp.path),
             name: "local",
           },
         ])
diff --git a/packages/opencode/test/control-plane/worktree-adaptor.test.ts b/packages/opencode/test/control-plane/worktree-adaptor.test.ts
new file mode 100644
index 000000000000..82ed14ede0cb
--- /dev/null
+++ b/packages/opencode/test/control-plane/worktree-adaptor.test.ts
@@ -0,0 +1,49 @@
+import { expect, mock, test } from "bun:test"
+import path from "path"
+
+import { Path } from "../../src/path/path"
+import { ProjectID } from "../../src/project/schema"
+import { WorkspaceID } from "../../src/control-plane/schema"
+
+let seen: { workspace: string | null; directory: string | null } | undefined
+
+mock.module("../../src/control-plane/workspace-server/server", () => ({
+  WorkspaceServer: {
+    App() {
+      return {
+        fetch(input: Request) {
+          seen = {
+            workspace: input.headers.get("x-opencode-workspace"),
+            directory: input.headers.get("x-opencode-directory"),
+          }
+          return Promise.resolve(new Response("ok"))
+        },
+      }
+    },
+  },
+}))
+
+const { WorktreeAdaptor } = await import("../../src/control-plane/adaptors/worktree")
+
+test("worktree adaptor forwards workspace and directory headers", async () => {
+  seen = undefined
+  const dir = path.join(process.cwd(), "100% ready")
+
+  const res = await WorktreeAdaptor.fetch(
+    {
+      id: WorkspaceID.parse("wrk_test_workspace"),
+      type: "worktree",
+      branch: "dev",
+      name: "test",
+      directory: Path.pretty(dir),
+      extra: null,
+      projectID: ProjectID.make("project_test"),
+    },
+    "/event",
+  )
+
+  expect(res.status).toBe(200)
+  expect(seen).toBeDefined()
+  expect(seen!.workspace).toBe("wrk_test_workspace")
+  expect(seen!.directory).toBe(dir)
+})
diff --git a/packages/opencode/test/file/index.test.ts b/packages/opencode/test/file/index.test.ts
index fae3ac1f2867..b8ef6ab15a45 100644
--- a/packages/opencode/test/file/index.test.ts
+++ b/packages/opencode/test/file/index.test.ts
@@ -3,6 +3,7 @@ import { $ } from "bun"
 import path from "path"
 import fs from "fs/promises"
 import { File } from "../../src/file"
+import { Path } from "../../src/path/path"
 import { Instance } from "../../src/project/instance"
 import { Filesystem } from "../../src/util/filesystem"
 import { tmpdir } from "../fixture/fixture"
@@ -631,8 +632,21 @@ describe("file/index Filesystem patterns", () => {
           const nodes = await File.list("sub")
           expect(nodes.length).toBe(2)
           expect(nodes.map((n) => n.name).sort()).toEqual(["a.txt", "b.txt"])
-          // Paths should be relative to project root (normalize for Windows)
-          expect(nodes[0].path.replaceAll("\\", "/").startsWith("sub/")).toBe(true)
+          expect(nodes.every((n) => n.path.startsWith("sub/"))).toBe(true)
+        },
+      })
+    })
+
+    test("returns repo-normalized paths for nested entries", async () => {
+      await using tmp = await tmpdir({ git: true })
+      await fs.mkdir(path.join(tmp.path, "src"))
+      await fs.writeFile(path.join(tmp.path, "src", "main.ts"), "", "utf-8")
+
+      await Instance.provide({
+        directory: tmp.path,
+        fn: async () => {
+          const nodes = await File.list()
+          expect(String(nodes.find((n) => n.name === "src")?.path)).toBe("src")
         },
       })
     })
@@ -673,8 +687,10 @@ describe("file/index Filesystem patterns", () => {
       await fs.writeFile(path.join(tmp.path, "utils.ts"), "utils", "utf-8")
       await fs.writeFile(path.join(tmp.path, "readme.md"), "readme", "utf-8")
       await fs.mkdir(path.join(tmp.path, "src"))
+      await fs.mkdir(path.join(tmp.path, "src", ".cache"))
       await fs.mkdir(path.join(tmp.path, ".hidden"))
       await fs.writeFile(path.join(tmp.path, "src", "main.ts"), "main", "utf-8")
+      await fs.writeFile(path.join(tmp.path, "src", ".cache", "tmp.ts"), "tmp", "utf-8")
       await fs.writeFile(path.join(tmp.path, ".hidden", "secret.ts"), "secret", "utf-8")
       return tmp
     }
@@ -715,9 +731,8 @@ describe("file/index Filesystem patterns", () => {
 
           const result = await File.search({ query: "", type: "directory" })
           expect(result.length).toBeGreaterThan(0)
-          // Find first hidden dir index
-          const firstHidden = result.findIndex((d) => d.split("/").some((p) => p.startsWith(".") && p.length > 1))
-          const lastVisible = result.findLastIndex((d) => !d.split("/").some((p) => p.startsWith(".") && p.length > 1))
+          const firstHidden = result.findIndex((d) => Path.hidden(d))
+          const lastVisible = result.findLastIndex((d) => !Path.hidden(d))
           if (firstHidden >= 0 && lastVisible >= 0) {
             expect(firstHidden).toBeGreaterThan(lastVisible)
           }
@@ -802,6 +817,21 @@ describe("file/index Filesystem patterns", () => {
       })
     })
 
+    test("query with a hidden prefix keeps hidden results first", async () => {
+      await using tmp = await setupSearchableRepo()
+
+      await Instance.provide({
+        directory: tmp.path,
+        fn: async () => {
+          await File.init()
+
+          const result = await File.search({ query: "src/.", type: "directory" })
+          expect(result.length).toBeGreaterThan(0)
+          expect(result[0]).toContain("src/.cache")
+        },
+      })
+    })
+
     test("search refreshes after init when files change", async () => {
       await using tmp = await setupSearchableRepo()
 
@@ -814,7 +844,7 @@ describe("file/index Filesystem patterns", () => {
           await fs.writeFile(path.join(tmp.path, "fresh.ts"), "fresh", "utf-8")
 
           const result = await File.search({ query: "fresh", type: "file" })
-          expect(result).toContain("fresh.ts")
+          expect(result).toContain(Path.repo("fresh.ts"))
         },
       })
     })
@@ -895,7 +925,7 @@ describe("file/index Filesystem patterns", () => {
         fn: async () => {
           await File.init()
           const results = await File.search({ query: "a.ts", type: "file" })
-          expect(results).toContain("a.ts")
+          expect(results).toContain(Path.repo("a.ts"))
           const results2 = await File.search({ query: "b.ts", type: "file" })
           expect(results2).not.toContain("b.ts")
         },
@@ -906,7 +936,7 @@ describe("file/index Filesystem patterns", () => {
         fn: async () => {
           await File.init()
           const results = await File.search({ query: "b.ts", type: "file" })
-          expect(results).toContain("b.ts")
+          expect(results).toContain(Path.repo("b.ts"))
           const results2 = await File.search({ query: "a.ts", type: "file" })
           expect(results2).not.toContain("a.ts")
         },
@@ -922,7 +952,7 @@ describe("file/index Filesystem patterns", () => {
         fn: async () => {
           await File.init()
           const results = await File.search({ query: "before", type: "file" })
-          expect(results).toContain("before.ts")
+          expect(results).toContain(Path.repo("before.ts"))
         },
       })
 
@@ -936,7 +966,7 @@ describe("file/index Filesystem patterns", () => {
         fn: async () => {
           await File.init()
           const results = await File.search({ query: "after", type: "file" })
-          expect(results).toContain("after.ts")
+          expect(results).toContain(Path.repo("after.ts"))
           const stale = await File.search({ query: "before", type: "file" })
           expect(stale).not.toContain("before.ts")
         },
diff --git a/packages/opencode/test/file/path-traversal.test.ts b/packages/opencode/test/file/path-traversal.test.ts
index 44ae8f154357..2073974687be 100644
--- a/packages/opencode/test/file/path-traversal.test.ts
+++ b/packages/opencode/test/file/path-traversal.test.ts
@@ -1,33 +1,52 @@
 import { test, expect, describe } from "bun:test"
 import path from "path"
 import fs from "fs/promises"
-import { Filesystem } from "../../src/util/filesystem"
 import { File } from "../../src/file"
 import { Instance } from "../../src/project/instance"
+import { Path } from "../../src/path/path"
 import { tmpdir } from "../fixture/fixture"
 
-describe("Filesystem.contains", () => {
+async function link(target: string, alias: string) {
+  await fs.symlink(target, alias, process.platform === "win32" ? "junction" : "dir")
+}
+
+describe("Path.contains", () => {
   test("allows paths within project", () => {
-    expect(Filesystem.contains("/project", "/project/src")).toBe(true)
-    expect(Filesystem.contains("/project", "/project/src/file.ts")).toBe(true)
-    expect(Filesystem.contains("/project", "/project")).toBe(true)
+    expect(Path.contains("/project", "/project/src")).toBe(true)
+    expect(Path.contains("/project", "/project/src/file.ts")).toBe(true)
+    expect(Path.contains("/project", "/project")).toBe(true)
   })
 
   test("blocks ../ traversal", () => {
-    expect(Filesystem.contains("/project", "/project/../etc")).toBe(false)
-    expect(Filesystem.contains("/project", "/project/src/../../etc")).toBe(false)
-    expect(Filesystem.contains("/project", "/etc/passwd")).toBe(false)
+    expect(Path.contains("/project", "/project/../etc")).toBe(false)
+    expect(Path.contains("/project", "/project/src/../../etc")).toBe(false)
+    expect(Path.contains("/project", "/etc/passwd")).toBe(false)
   })
 
   test("blocks absolute paths outside project", () => {
-    expect(Filesystem.contains("/project", "/etc/passwd")).toBe(false)
-    expect(Filesystem.contains("/project", "/tmp/file")).toBe(false)
-    expect(Filesystem.contains("/home/user/project", "/home/user/other")).toBe(false)
+    expect(Path.contains("/project", "/etc/passwd")).toBe(false)
+    expect(Path.contains("/project", "/tmp/file")).toBe(false)
+    expect(Path.contains("/home/user/project", "/home/user/other")).toBe(false)
   })
 
   test("handles prefix collision edge cases", () => {
-    expect(Filesystem.contains("/project", "/project-other/file")).toBe(false)
-    expect(Filesystem.contains("/project", "/projectfile")).toBe(false)
+    expect(Path.contains("/project", "/project-other/file")).toBe(false)
+    expect(Path.contains("/project", "/projectfile")).toBe(false)
+  })
+
+  test("blocks absolute-relative path mixes", () => {
+    const abs = process.platform === "win32" ? "C:\\project" : "/project"
+    const rel = process.platform === "win32" ? "project\\src\\file.ts" : "project/src/file.ts"
+
+    expect(Path.contains(abs, rel)).toBe(false)
+    expect(Path.contains(rel, path.join(abs, "src", "file.ts"))).toBe(false)
+  })
+
+  test("blocks different roots", () => {
+    if (process.platform !== "win32") return
+
+    expect(Path.contains("C:\\project", "D:\\project\\file.ts")).toBe(false)
+    expect(Path.contains("C:\\project", "\\\\server\\share\\file.ts")).toBe(false)
   })
 })
 
@@ -84,6 +103,56 @@ describe("File.read path traversal protection", () => {
       },
     })
   })
+
+  test("returns empty content for missing paths within project", async () => {
+    await using tmp = await tmpdir()
+
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        await expect(File.read("missing.txt")).resolves.toMatchObject({
+          type: "text",
+          content: "",
+        })
+      },
+    })
+  })
+
+  test("rejects symlink escape for existing files", async () => {
+    await using outer = await tmpdir({
+      init: async (dir) => {
+        await Bun.write(path.join(dir, "secret.txt"), "secret")
+      },
+    })
+    await using tmp = await tmpdir({
+      init: async (dir) => {
+        await link(outer.path, path.join(dir, "link"))
+      },
+    })
+
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        await expect(File.read("link/secret.txt")).rejects.toThrow("Access denied: path escapes project directory")
+      },
+    })
+  })
+
+  test("rejects symlink escape for missing files", async () => {
+    await using outer = await tmpdir()
+    await using tmp = await tmpdir({
+      init: async (dir) => {
+        await link(outer.path, path.join(dir, "link"))
+      },
+    })
+
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        await expect(File.read("link/missing.txt")).rejects.toThrow("Access denied: path escapes project directory")
+      },
+    })
+  })
 })
 
 describe("File.list path traversal protection", () => {
@@ -113,6 +182,26 @@ describe("File.list path traversal protection", () => {
       },
     })
   })
+
+  test("rejects symlink escape for directory listings", async () => {
+    await using outer = await tmpdir({
+      init: async (dir) => {
+        await fs.mkdir(path.join(dir, "nested"), { recursive: true })
+      },
+    })
+    await using tmp = await tmpdir({
+      init: async (dir) => {
+        await link(outer.path, path.join(dir, "link"))
+      },
+    })
+
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        await expect(File.list("link/nested")).rejects.toThrow("Access denied: path escapes project directory")
+      },
+    })
+  })
 })
 
 describe("Instance.containsPath", () => {
diff --git a/packages/opencode/test/file/time.test.ts b/packages/opencode/test/file/time.test.ts
index db7eaaae0d8b..bdb783e23b5a 100644
--- a/packages/opencode/test/file/time.test.ts
+++ b/packages/opencode/test/file/time.test.ts
@@ -4,6 +4,7 @@ import fs from "fs/promises"
 import { FileTime } from "../../src/file/time"
 import { Instance } from "../../src/project/instance"
 import { SessionID } from "../../src/session/schema"
+import { Path } from "../../src/path/path"
 import { Filesystem } from "../../src/util/filesystem"
 import { tmpdir } from "../fixture/fixture"
 
@@ -36,12 +37,12 @@ describe("file/time", () => {
       await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          const before = await FileTime.get(sessionID, filepath)
+          const before = await FileTime.get(sessionID, Path.pretty(filepath))
           expect(before).toBeUndefined()
 
-          await FileTime.read(sessionID, filepath)
+          await FileTime.read(sessionID, Path.pretty(filepath))
 
-          const after = await FileTime.get(sessionID, filepath)
+          const after = await FileTime.get(sessionID, Path.pretty(filepath))
           expect(after).toBeInstanceOf(Date)
           expect(after!.getTime()).toBeGreaterThan(0)
         },
@@ -56,11 +57,11 @@ describe("file/time", () => {
       await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          await FileTime.read(SessionID.make("ses_00000000000000000000000002"), filepath)
-          await FileTime.read(SessionID.make("ses_00000000000000000000000003"), filepath)
+          await FileTime.read(SessionID.make("ses_00000000000000000000000002"), Path.pretty(filepath))
+          await FileTime.read(SessionID.make("ses_00000000000000000000000003"), Path.pretty(filepath))
 
-          const time1 = await FileTime.get(SessionID.make("ses_00000000000000000000000002"), filepath)
-          const time2 = await FileTime.get(SessionID.make("ses_00000000000000000000000003"), filepath)
+          const time1 = await FileTime.get(SessionID.make("ses_00000000000000000000000002"), Path.pretty(filepath))
+          const time2 = await FileTime.get(SessionID.make("ses_00000000000000000000000003"), Path.pretty(filepath))
 
           expect(time1).toBeDefined()
           expect(time2).toBeDefined()
@@ -76,11 +77,11 @@ describe("file/time", () => {
       await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          await FileTime.read(sessionID, filepath)
-          const first = await FileTime.get(sessionID, filepath)
+          await FileTime.read(sessionID, Path.pretty(filepath))
+          const first = await FileTime.get(sessionID, Path.pretty(filepath))
 
-          await FileTime.read(sessionID, filepath)
-          const second = await FileTime.get(sessionID, filepath)
+          await FileTime.read(sessionID, Path.pretty(filepath))
+          const second = await FileTime.get(sessionID, Path.pretty(filepath))
 
           expect(second!.getTime()).toBeGreaterThanOrEqual(first!.getTime())
         },
@@ -97,14 +98,14 @@ describe("file/time", () => {
       await Instance.provide({
         directory: one.path,
         fn: async () => {
-          await FileTime.read(sessionID, filepath)
+          await FileTime.read(sessionID, Path.pretty(filepath))
         },
       })
 
       await Instance.provide({
         directory: two.path,
         fn: async () => {
-          expect(await FileTime.get(sessionID, filepath)).toBeUndefined()
+          expect(await FileTime.get(sessionID, Path.pretty(filepath))).toBeUndefined()
         },
       })
     })
@@ -120,8 +121,8 @@ describe("file/time", () => {
       await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          await FileTime.read(sessionID, filepath)
-          await FileTime.assert(sessionID, filepath)
+          await FileTime.read(sessionID, Path.pretty(filepath))
+          await FileTime.assert(sessionID, Path.pretty(filepath))
         },
       })
     })
@@ -134,7 +135,7 @@ describe("file/time", () => {
       await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          await expect(FileTime.assert(sessionID, filepath)).rejects.toThrow("You must read file")
+          await expect(FileTime.assert(sessionID, Path.pretty(filepath))).rejects.toThrow("You must read file")
         },
       })
     })
@@ -148,10 +149,12 @@ describe("file/time", () => {
       await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          await FileTime.read(sessionID, filepath)
+          await FileTime.read(sessionID, Path.pretty(filepath))
           await fs.writeFile(filepath, "modified content", "utf-8")
           await touch(filepath, 2_000)
-          await expect(FileTime.assert(sessionID, filepath)).rejects.toThrow("modified since it was last read")
+          await expect(FileTime.assert(sessionID, Path.pretty(filepath))).rejects.toThrow(
+            "modified since it was last read",
+          )
         },
       })
     })
@@ -165,13 +168,13 @@ describe("file/time", () => {
       await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          await FileTime.read(sessionID, filepath)
+          await FileTime.read(sessionID, Path.pretty(filepath))
           await fs.writeFile(filepath, "modified", "utf-8")
           await touch(filepath, 2_000)
 
           let error: Error | undefined
           try {
-            await FileTime.assert(sessionID, filepath)
+            await FileTime.assert(sessionID, Path.pretty(filepath))
           } catch (e) {
             error = e as Error
           }
@@ -192,7 +195,7 @@ describe("file/time", () => {
         directory: tmp.path,
         fn: async () => {
           let executed = false
-          await FileTime.withLock(filepath, async () => {
+          await FileTime.withLock(Path.pretty(filepath), async () => {
             executed = true
             return "result"
           })
@@ -208,7 +211,7 @@ describe("file/time", () => {
       await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          const result = await FileTime.withLock(filepath, async () => {
+          const result = await FileTime.withLock(Path.pretty(filepath), async () => {
             return "success"
           })
           expect(result).toBe("success")
@@ -227,7 +230,7 @@ describe("file/time", () => {
           const hold = gate()
           const ready = gate()
 
-          const op1 = FileTime.withLock(filepath, async () => {
+          const op1 = FileTime.withLock(Path.pretty(filepath), async () => {
             order.push(1)
             ready.open()
             await hold.wait
@@ -236,7 +239,7 @@ describe("file/time", () => {
 
           await ready.wait
 
-          const op2 = FileTime.withLock(filepath, async () => {
+          const op2 = FileTime.withLock(Path.pretty(filepath), async () => {
             order.push(3)
             order.push(4)
           })
@@ -262,7 +265,7 @@ describe("file/time", () => {
           const hold = gate()
           const ready = gate()
 
-          const op1 = FileTime.withLock(filepath1, async () => {
+          const op1 = FileTime.withLock(Path.pretty(filepath1), async () => {
             started1 = true
             ready.open()
             await hold.wait
@@ -271,7 +274,7 @@ describe("file/time", () => {
 
           await ready.wait
 
-          const op2 = FileTime.withLock(filepath2, async () => {
+          const op2 = FileTime.withLock(Path.pretty(filepath2), async () => {
             started2 = true
             hold.open()
           })
@@ -291,13 +294,13 @@ describe("file/time", () => {
         directory: tmp.path,
         fn: async () => {
           await expect(
-            FileTime.withLock(filepath, async () => {
+            FileTime.withLock(Path.pretty(filepath), async () => {
               throw new Error("Test error")
             }),
           ).rejects.toThrow("Test error")
 
           let executed = false
-          await FileTime.withLock(filepath, async () => {
+          await FileTime.withLock(Path.pretty(filepath), async () => {
             executed = true
           })
           expect(executed).toBe(true)
@@ -316,13 +319,13 @@ describe("file/time", () => {
       await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          await FileTime.read(sessionID, filepath)
+          await FileTime.read(sessionID, Path.pretty(filepath))
 
           const stats = Filesystem.stat(filepath)
           expect(stats?.mtime).toBeInstanceOf(Date)
           expect(stats!.mtime.getTime()).toBeGreaterThan(0)
 
-          await FileTime.assert(sessionID, filepath)
+          await FileTime.assert(sessionID, Path.pretty(filepath))
         },
       })
     })
@@ -336,7 +339,7 @@ describe("file/time", () => {
       await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          await FileTime.read(sessionID, filepath)
+          await FileTime.read(sessionID, Path.pretty(filepath))
 
           const originalStat = Filesystem.stat(filepath)
 
@@ -346,7 +349,7 @@ describe("file/time", () => {
           const newStat = Filesystem.stat(filepath)
           expect(newStat!.mtime.getTime()).toBeGreaterThan(originalStat!.mtime.getTime())
 
-          await expect(FileTime.assert(sessionID, filepath)).rejects.toThrow()
+          await expect(FileTime.assert(sessionID, Path.pretty(filepath))).rejects.toThrow()
         },
       })
     })
diff --git a/packages/opencode/test/filesystem/filesystem.test.ts b/packages/opencode/test/filesystem/filesystem.test.ts
index ca73b3336bc7..98198007e46a 100644
--- a/packages/opencode/test/filesystem/filesystem.test.ts
+++ b/packages/opencode/test/filesystem/filesystem.test.ts
@@ -2,6 +2,7 @@ import { describe, test, expect } from "bun:test"
 import { Effect, Layer } from "effect"
 import { NodeFileSystem } from "@effect/platform-node"
 import { AppFileSystem } from "../../src/filesystem"
+import { Path } from "../../src/path/path"
 import { testEffect } from "../lib/effect"
 import path from "path"
 
@@ -305,15 +306,15 @@ describe("AppFileSystem", () => {
       expect(AppFileSystem.mimeType("unknown.qzx")).toBe("application/octet-stream")
     })
 
-    test("contains checks path containment", () => {
-      expect(AppFileSystem.contains("/a/b", "/a/b/c")).toBe(true)
-      expect(AppFileSystem.contains("/a/b", "/a/c")).toBe(false)
+    test("Path.contains checks path containment", () => {
+      expect(Path.contains("/a/b", "/a/b/c")).toBe(true)
+      expect(Path.contains("/a/b", "/a/c")).toBe(false)
     })
 
-    test("overlaps detects overlapping paths", () => {
-      expect(AppFileSystem.overlaps("/a/b", "/a/b/c")).toBe(true)
-      expect(AppFileSystem.overlaps("/a/b/c", "/a/b")).toBe(true)
-      expect(AppFileSystem.overlaps("/a", "/b")).toBe(false)
+    test("Path.overlaps detects overlapping paths", () => {
+      expect(Path.overlaps("/a/b", "/a/b/c")).toBe(true)
+      expect(Path.overlaps("/a/b/c", "/a/b")).toBe(true)
+      expect(Path.overlaps("/a", "/b")).toBe(false)
     })
   })
 })
diff --git a/packages/opencode/test/fixture/instance.ts b/packages/opencode/test/fixture/instance.ts
index 67af82fc8b41..533f6327ba23 100644
--- a/packages/opencode/test/fixture/instance.ts
+++ b/packages/opencode/test/fixture/instance.ts
@@ -1,5 +1,6 @@
 import { ConfigProvider, Layer, ManagedRuntime } from "effect"
 import { InstanceContext } from "../../src/effect/instance-context"
+import { Path } from "../../src/path/path"
 import { Instance } from "../../src/project/instance"
 
 /** ConfigProvider that enables the experimental file watcher. */
@@ -29,8 +30,8 @@ export function withServices<S>(
     fn: async () => {
       const ctx = Layer.sync(InstanceContext, () =>
         InstanceContext.of({
-          directory: Instance.directory,
-          worktree: Instance.worktree,
+          directory: Path.pretty(Instance.directory),
+          worktree: Path.pretty(Instance.worktree),
           project: Instance.project,
         }),
       )
diff --git a/packages/opencode/test/fixture/lsp/fake-lsp-server.js b/packages/opencode/test/fixture/lsp/fake-lsp-server.js
index 39e578801269..6f6f0a0fa5ec 100644
--- a/packages/opencode/test/fixture/lsp/fake-lsp-server.js
+++ b/packages/opencode/test/fixture/lsp/fake-lsp-server.js
@@ -64,6 +64,14 @@ function handle(raw) {
   if (data.method === "workspace/didChangeConfiguration") {
     return
   }
+  if (data.method === "test/publishDiagnostics") {
+    send({
+      jsonrpc: "2.0",
+      method: "textDocument/publishDiagnostics",
+      params: data.params,
+    })
+    return
+  }
   if (data.method === "test/trigger") {
     const method = data.params && data.params.method
     if (method) sendRequest(method, {})
diff --git a/packages/opencode/test/lib/windows-path.ts b/packages/opencode/test/lib/windows-path.ts
new file mode 100644
index 000000000000..55c9031bbef0
--- /dev/null
+++ b/packages/opencode/test/lib/windows-path.ts
@@ -0,0 +1,26 @@
+import { Path } from "../../src/path/path"
+
+type Item = {
+  name: string
+  path: string
+}
+
+function glob(path: string) {
+  return `${path.replace(/[\\/]+$/, "")}${path.includes("\\") ? "\\*" : "/*"}`
+}
+
+export function win(input: string) {
+  const path = String(Path.pretty(input, { platform: "win32" }))
+  const posix = String(Path.posix(path, { platform: "win32" }))
+  const drive = posix.match(/^([A-Z]):/)?.[1]
+  if (!drive) throw new Error(`Expected Windows path: ${input}`)
+  const rest = posix.slice(2)
+  const base: Item[] = [
+    { name: "native", path },
+    { name: "slash", path: posix },
+    { name: "git", path: `/${drive.toLowerCase()}${rest}` },
+    { name: "cygwin", path: `/cygdrive/${drive.toLowerCase()}${rest}` },
+    { name: "wsl", path: `/mnt/${drive.toLowerCase()}${rest}` },
+  ]
+  return base.map((item) => ({ ...item, glob: glob(item.path) }))
+}
diff --git a/packages/opencode/test/lsp/client.test.ts b/packages/opencode/test/lsp/client.test.ts
index c2ba3ac5b09f..fc639edcdef4 100644
--- a/packages/opencode/test/lsp/client.test.ts
+++ b/packages/opencode/test/lsp/client.test.ts
@@ -1,9 +1,12 @@
 import { describe, expect, test, beforeEach } from "bun:test"
+import fs from "fs/promises"
 import path from "path"
+import { Path } from "../../src/path/path"
 import { LSPClient } from "../../src/lsp/client"
 import { LSPServer } from "../../src/lsp/server"
 import { Instance } from "../../src/project/instance"
 import { Log } from "../../src/util/log"
+import { tmpdir } from "../fixture/fixture"
 
 // Minimal fake LSP server that speaks JSON-RPC over stdio
 function spawnFakeServer() {
@@ -30,7 +33,7 @@ describe("LSPClient interop", () => {
         LSPClient.create({
           serverID: "fake",
           server: handle as unknown as LSPServer.Handle,
-          root: process.cwd(),
+          root: Path.pretty(process.cwd()),
         }),
     })
 
@@ -54,7 +57,7 @@ describe("LSPClient interop", () => {
         LSPClient.create({
           serverID: "fake",
           server: handle as unknown as LSPServer.Handle,
-          root: process.cwd(),
+          root: Path.pretty(process.cwd()),
         }),
     })
 
@@ -78,7 +81,7 @@ describe("LSPClient interop", () => {
         LSPClient.create({
           serverID: "fake",
           server: handle as unknown as LSPServer.Handle,
-          root: process.cwd(),
+          root: Path.pretty(process.cwd()),
         }),
     })
 
@@ -92,4 +95,124 @@ describe("LSPClient interop", () => {
 
     await client.shutdown()
   })
+
+  test("preserves alias paths in diagnostics", async () => {
+    if (process.platform !== "win32") return
+    await using tmp = await tmpdir()
+
+    const target = path.join(tmp.path, "Target")
+    const alias = path.join(tmp.path, "Alias")
+    const file = path.join(alias, "file.ts")
+    const real = path.join(target, "file.ts")
+    await fs.mkdir(target, { recursive: true })
+    await fs.symlink(target, alias, "junction")
+    await Bun.write(file, "const x = 1\n")
+
+    const handle = spawnFakeServer() as any
+
+    const client = await Instance.provide({
+      directory: alias,
+      fn: () =>
+        LSPClient.create({
+          serverID: "fake",
+          server: handle as unknown as LSPServer.Handle,
+          root: Path.pretty(alias),
+        }),
+    })
+
+    await client.connection.sendNotification("test/publishDiagnostics", {
+      uri: String(Path.uri(file)),
+      diagnostics: [
+        {
+          range: {
+            start: { line: 0, character: 0 },
+            end: { line: 0, character: 1 },
+          },
+          message: "boom",
+          severity: 1,
+        },
+      ],
+    })
+
+    await new Promise((r) => setTimeout(r, 100))
+
+    expect([...client.diagnostics.entries()]).toEqual([
+      [
+        file,
+        [
+          expect.objectContaining({
+            message: "boom",
+            severity: 1,
+          }),
+        ],
+      ],
+    ])
+    expect([...client.diagnostics.keys()]).not.toContain(real)
+
+    await client.shutdown()
+  })
+
+  test("coalesces diagnostics by path key", async () => {
+    if (process.platform !== "win32") return
+    await using tmp = await tmpdir()
+
+    const file = path.join(tmp.path, "File.ts")
+    await Bun.write(file, "const x = 1\n")
+    const lower = file.toLowerCase()
+
+    const handle = spawnFakeServer() as any
+
+    const client = await Instance.provide({
+      directory: tmp.path,
+      fn: () =>
+        LSPClient.create({
+          serverID: "fake",
+          server: handle as unknown as LSPServer.Handle,
+          root: Path.pretty(tmp.path),
+        }),
+    })
+
+    await client.connection.sendNotification("test/publishDiagnostics", {
+      uri: String(Path.uri(file)),
+      diagnostics: [
+        {
+          range: {
+            start: { line: 0, character: 0 },
+            end: { line: 0, character: 1 },
+          },
+          message: "first",
+          severity: 1,
+        },
+      ],
+    })
+    await client.connection.sendNotification("test/publishDiagnostics", {
+      uri: String(Path.uri(lower)),
+      diagnostics: [
+        {
+          range: {
+            start: { line: 1, character: 0 },
+            end: { line: 1, character: 1 },
+          },
+          message: "second",
+          severity: 1,
+        },
+      ],
+    })
+
+    await new Promise((r) => setTimeout(r, 100))
+
+    expect([...client.diagnostics.entries()]).toEqual([
+      [
+        file,
+        [
+          expect.objectContaining({
+            message: "second",
+            severity: 1,
+          }),
+        ],
+      ],
+    ])
+
+    await client.shutdown()
+  })
 })
diff --git a/packages/opencode/test/lsp/index.test.ts b/packages/opencode/test/lsp/index.test.ts
new file mode 100644
index 000000000000..ebdc6fe4fc55
--- /dev/null
+++ b/packages/opencode/test/lsp/index.test.ts
@@ -0,0 +1,88 @@
+import { afterEach, beforeEach, expect, spyOn, test } from "bun:test"
+import path from "path"
+
+import { Config } from "../../src/config/config"
+import { LSPClient } from "../../src/lsp/client"
+import { LSPServer } from "../../src/lsp/server"
+import { Path } from "../../src/path/path"
+import { Instance } from "../../src/project/instance"
+import { Log } from "../../src/util/log"
+import { tmpdir } from "../fixture/fixture"
+
+Log.init({ print: false })
+
+let roots: string[] = []
+let calls: string[] = []
+let opens: string[] = []
+let getSpy: ReturnType<typeof spyOn> | undefined
+let createSpy: ReturnType<typeof spyOn> | undefined
+let fake: unknown
+
+const { LSP } = await import("../../src/lsp/index")
+
+beforeEach(() => {
+  getSpy = spyOn(Config, "get").mockResolvedValue({})
+  fake = {
+    id: "fake",
+    extensions: [".ts"],
+    root: async (file: string) => (path.basename(file) === "first.ts" ? roots[0] : roots[1]),
+    spawn: async () => ({
+      process: {
+        pid: 1,
+        kill() {},
+      },
+    }),
+  }
+  ;(LSPServer as Record<string, unknown>)["Fake"] = fake
+  createSpy = spyOn(LSPClient, "create").mockImplementation(async (input) => {
+    calls.push(input.root)
+    return {
+      root: input.root,
+      rootKey: String(Path.key(input.root)),
+      serverID: input.serverID,
+      connection: {
+        sendRequest: async () => null,
+      },
+      notify: {
+        open: async (input: { path: string }) => {
+          opens.push(input.path)
+        },
+      },
+      diagnostics: new Map(),
+      waitForDiagnostics: async () => {},
+      shutdown: async () => {},
+    } as unknown as NonNullable<Awaited<ReturnType<typeof LSPClient.create>>>
+  })
+})
+
+afterEach(async () => {
+  roots = []
+  calls = []
+  opens = []
+  getSpy?.mockRestore()
+  getSpy = undefined
+  createSpy?.mockRestore()
+  createSpy = undefined
+  delete (LSPServer as Record<string, unknown>)["Fake"]
+  fake = undefined
+  await Instance.disposeAll()
+})
+
+test("reuses clients for equivalent roots", async () => {
+  if (process.platform !== "win32") return
+  await using tmp = await tmpdir()
+
+  roots = [tmp.path, tmp.path.toLowerCase().replaceAll("\\", "/")]
+
+  await Instance.provide({
+    directory: tmp.path,
+    fn: async () => {
+      await LSP.touchFile(path.join(tmp.path, "first.ts"))
+      await LSP.touchFile(path.join(roots[1], "second.ts"))
+    },
+  })
+
+  expect(calls).toHaveLength(1)
+  expect(String(Path.key(calls[0]!))).toBe(String(Path.key(tmp.path)))
+  expect(opens).toHaveLength(2)
+})
diff --git a/packages/opencode/test/lsp/server.test.ts b/packages/opencode/test/lsp/server.test.ts
new file mode 100644
index 000000000000..091be108b6b5
--- /dev/null
+++ b/packages/opencode/test/lsp/server.test.ts
@@ -0,0 +1,35 @@
+import { afterEach, describe, expect, test } from "bun:test"
+import fs from "fs/promises"
+import path from "path"
+import { LSPServer } from "../../src/lsp/server"
+import { Path } from "../../src/path/path"
+import { Instance } from "../../src/project/instance"
+import { tmpdir } from "../fixture/fixture"
+
+afterEach(async () => {
+  await Instance.disposeAll()
+})
+
+describe("LSPServer.RustAnalyzer.root", () => {
+  test("stops before prefix-collision siblings outside worktree", async () => {
+    await using tmp = await tmpdir({ git: true })
+    const other = tmp.path + "-other"
+
+    try {
+      await fs.mkdir(path.join(other, "member", "src"), { recursive: true })
+      await Bun.write(path.join(other, "Cargo.toml"), "[workspace]\nmembers = [\"member\"]\n")
+      await Bun.write(path.join(other, "member", "Cargo.toml"), "[package]\nname = \"member\"\nversion = \"0.1.0\"\n")
+      await Bun.write(path.join(other, "member", "src", "lib.rs"), "pub fn it_works() {}\n")
+
+      await Instance.provide({
+        directory: tmp.path,
+        fn: async () => {
+          const root = await LSPServer.RustAnalyzer.root(Path.pretty(path.join(other, "member", "src", "lib.rs")))
+          expect(String(root)).toBe(path.join(other, "member"))
+        },
+      })
+    } finally {
+      await fs.rm(other, { recursive: true, force: true })
+    }
+  })
+})
diff --git a/packages/opencode/test/path/migrate.test.ts b/packages/opencode/test/path/migrate.test.ts
new file mode 100644
index 000000000000..9926253224b3
--- /dev/null
+++ b/packages/opencode/test/path/migrate.test.ts
@@ -0,0 +1,162 @@
+import { afterEach, describe, expect, test } from "bun:test"
+import path from "path"
+import { Project } from "../../src/project/project"
+import { Session } from "../../src/session"
+import { Database, eq } from "../../src/storage/db"
+import { ProjectTable } from "../../src/project/project.sql"
+import { SessionTable } from "../../src/session/session.sql"
+import { WorkspaceTable } from "../../src/control-plane/workspace.sql"
+import { WorkspaceID } from "../../src/control-plane/schema"
+import { SessionID } from "../../src/session/schema"
+import { tmpdir } from "../fixture/fixture"
+import { resetDatabase } from "../fixture/db"
+import { PathMigration } from "../../src/path/migrate"
+import { Path } from "../../src/path/path"
+import { PrettyPath } from "../../src/path/schema"
+import { Filesystem } from "../../src/util/filesystem"
+
+afterEach(async () => {
+  delete process.env.OPENCODE_FORCE_PATH_MIGRATION
+  await resetDatabase()
+})
+
+function raw(dir: string) {
+  if (process.platform === "win32") return path.join(dir.toUpperCase(), "child", "..")
+  return path.join(dir, "child", "..")
+}
+
+function sid() {
+  return SessionID.make(crypto.randomUUID())
+}
+
+describe("PathMigration.run", () => {
+  test("rewrites authoritative path rows and dedupes sandboxes", async () => {
+    await using tmp = await tmpdir({ git: true })
+    const box = path.join(tmp.path, "sandbox")
+    await Filesystem.write(path.join(box, ".keep"), "")
+
+    const { project } = await Project.fromDirectory(tmp.path)
+    const sessionID = sid()
+    const workspaceID = WorkspaceID.ascending()
+    const mark = path.join(tmp.path, "path-migration.json")
+    const now = Date.now()
+
+    Database.use((db) => {
+      db.insert(SessionTable)
+        .values({
+          id: sessionID,
+          project_id: project.id,
+          slug: sessionID,
+          directory: PrettyPath.make(raw(tmp.path)),
+          title: "test",
+          version: "0.0.0-test",
+          time_created: now,
+          time_updated: now,
+        })
+        .run()
+
+      db.insert(WorkspaceTable)
+        .values({
+          id: workspaceID,
+          type: "worktree",
+          branch: null,
+          name: "local",
+          directory: PrettyPath.make(raw(tmp.path)),
+          extra: null,
+          project_id: project.id,
+        })
+        .run()
+
+      db
+        .update(ProjectTable)
+        .set({
+          worktree: PrettyPath.make(raw(tmp.path)),
+          sandboxes: [PrettyPath.make(raw(box)), PrettyPath.make(path.join(raw(box), "again", "..")), PrettyPath.make(raw(tmp.path))],
+        })
+        .where(eq(ProjectTable.id, project.id))
+        .run()
+    })
+
+    const result = await PathMigration.run({ force: true, marker: mark })
+
+    expect(result.skipped).toBe(false)
+    expect(result.change).toEqual({
+      project: 1,
+      session: 1,
+      workspace: 1,
+    })
+    expect(await Filesystem.exists(mark)).toBe(true)
+
+    const prow = Database.use((db) => db.select().from(ProjectTable).where(eq(ProjectTable.id, project.id)).get())
+    const srow = Database.use((db) => db.select().from(SessionTable).where(eq(SessionTable.id, sessionID)).get())
+    const wrow = Database.use((db) => db.select().from(WorkspaceTable).where(eq(WorkspaceTable.id, workspaceID)).get())
+
+    expect(String(prow?.worktree)).toBe(tmp.path)
+    expect(prow?.sandboxes.map(String)).toEqual([box])
+    expect(String(srow?.directory)).toBe(tmp.path)
+    expect(String(wrow?.directory)).toBe(tmp.path)
+  })
+
+  test("normalizes new session rows on write", async () => {
+    await using tmp = await tmpdir({ git: true })
+    const { project } = await Project.fromDirectory(tmp.path)
+    const row = Session.toRow({
+      id: sid(),
+      slug: "slug",
+      projectID: project.id,
+        directory: Path.pretty(raw(tmp.path)),
+      title: "test",
+      version: "0.0.0-test",
+      time: {
+        created: 1,
+        updated: 1,
+      },
+    })
+
+    expect(String(row.directory)).toBe(tmp.path)
+  })
+
+  test("is idempotent and only reruns when forced", async () => {
+    await using tmp = await tmpdir({ git: true })
+    const { project } = await Project.fromDirectory(tmp.path)
+    const mark = path.join(tmp.path, "path-migration.json")
+
+    Database.use((db) =>
+      db
+        .update(ProjectTable)
+        .set({ worktree: PrettyPath.make(raw(tmp.path)) })
+        .where(eq(ProjectTable.id, project.id))
+        .run(),
+    )
+
+    const first = await PathMigration.run({ force: true, marker: mark })
+    const second = await PathMigration.run({ force: true, marker: mark })
+
+    expect(first.change.project).toBe(1)
+    expect(second.change).toEqual({
+      project: 0,
+      session: 0,
+      workspace: 0,
+    })
+
+    Database.use((db) =>
+      db
+        .update(ProjectTable)
+        .set({ worktree: PrettyPath.make(raw(tmp.path)) })
+        .where(eq(ProjectTable.id, project.id))
+        .run(),
+    )
+
+    const skip = await PathMigration.run({ marker: mark })
+    expect(skip.skipped).toBe(true)
+
+    const rawrow = Database.use((db) => db.select().from(ProjectTable).where(eq(ProjectTable.id, project.id)).get())
+    expect(rawrow?.worktree).not.toBe(tmp.path)
+
+    const forced = await PathMigration.run({ force: true, marker: mark })
+    const next = Database.use((db) => db.select().from(ProjectTable).where(eq(ProjectTable.id, project.id)).get())
+
+    expect(forced.change.project).toBe(1)
+    expect(String(next?.worktree)).toBe(tmp.path)
+  })
+})
diff --git a/packages/opencode/test/path/path.test.ts b/packages/opencode/test/path/path.test.ts
new file mode 100644
index 000000000000..cb375879b1cc
--- /dev/null
+++ b/packages/opencode/test/path/path.test.ts
@@ -0,0 +1,430 @@
+import { describe, expect, test } from "bun:test"
+import fs from "fs/promises"
+import path from "path"
+
+import { Path } from "../../src/path/path"
+import { tmpdir } from "../fixture/fixture"
+import { win as alias } from "../lib/windows-path"
+
+describe("path", () => {
+  describe("pretty()", () => {
+    const opts = { cwd: "C:\\work", platform: "win32" as const }
+
+    for (const [name, input] of [
+      ["slash drive", "/c/tmp/file.txt"],
+      ["slash drive with colon", "/C:/tmp/file.txt"],
+      ["cygdrive", "/cygdrive/c/tmp/file.txt"],
+      ["wsl", "/mnt/c/tmp/file.txt"],
+      ["file uri", "file:///C:/tmp/file.txt"],
+    ]) {
+      test(`normalizes ${name} on Windows`, () => {
+        expect(String(Path.pretty(input, opts))).toBe("C:\\tmp\\file.txt")
+      })
+    }
+
+    test("normalizes relative input to native absolute form", () => {
+      expect(String(Path.pretty("src/../file.ts", { cwd: "/repo", platform: "linux" }))).toBe("/repo/file.ts")
+    })
+
+    test("collapses Windows alias forms to the same pretty path", () => {
+      const file = "C:\\Users\\Dev\\tmp\\file.txt"
+      for (const item of alias(file)) {
+        expect(String(Path.pretty(item.path, { platform: "win32" }))).toBe(file)
+      }
+    })
+
+    test("normalizes Windows UNC alias forms", () => {
+      const file = "\\\\server\\share\\tmp\\file.txt"
+      for (const input of [file, "//server/share/tmp/file.txt", "file://server/share/tmp/file.txt"]) {
+        expect(String(Path.pretty(input, { platform: "win32" }))).toBe(file)
+      }
+    })
+
+    test("treats localhost file URIs as local files", () => {
+      expect(String(Path.pretty("file://localhost/C:/tmp/file.txt", { platform: "win32" }))).toBe("C:\\tmp\\file.txt")
+      expect(String(Path.pretty("file://localhost/tmp/file.txt", { platform: "linux" }))).toBe("/tmp/file.txt")
+    })
+  })
+
+  describe("isAbsolute()", () => {
+    test("treats file URIs as absolute", () => {
+      expect(Path.isAbsolute("file:///tmp/dir/file.txt", { platform: "linux" })).toBe(true)
+      expect(Path.isAbsolute("file:///C:/tmp/file.txt", { platform: "win32" })).toBe(true)
+    })
+
+    test("matches all Windows alias roots", () => {
+      for (const item of alias("C:\\Users\\Dev\\tmp\\file.txt")) {
+        expect(Path.isAbsolute(item.path, { platform: "win32" })).toBe(true)
+      }
+    })
+
+    test("treats UNC paths as absolute on Windows", () => {
+      expect(Path.isAbsolute("\\\\server\\share\\repo", { platform: "win32" })).toBe(true)
+      expect(Path.isAbsolute("//server/share/repo", { platform: "win32" })).toBe(true)
+      expect(Path.isAbsolute("file://server/share/repo", { platform: "win32" })).toBe(true)
+    })
+
+    test("keeps relative inputs relative", () => {
+      expect(Path.isAbsolute("src/file.ts", { platform: "linux" })).toBe(false)
+      expect(Path.isAbsolute("src/file.ts", { platform: "win32" })).toBe(false)
+    })
+  })
+
+  describe("key()", () => {
+    test("keeps the global slash sentinel stable", () => {
+      expect(String(Path.key("/"))).toBe("/")
+      expect(Path.eq("/", "/")).toBe(true)
+      expect(Path.eq("/", process.platform === "win32" ? "C:\\" : "/tmp")).toBe(false)
+    })
+
+    test("matches slash and case variants on Windows", () => {
+      const a = Path.key("C:\\Repo\\File.ts", { platform: "win32" })
+      const b = Path.key("c:/repo/file.ts", { platform: "win32" })
+      expect(a).toBe(b)
+      expect(Path.eq("C:\\Repo\\File.ts", "c:/repo/file.ts", { platform: "win32" })).toBe(true)
+      expect(Path.match("C:\\Repo\\File.ts", b, { platform: "win32" })).toBe(true)
+    })
+
+    test("matches all Windows alias forms", () => {
+      const [head, ...tail] = alias("C:\\Users\\Dev\\tmp\\file.txt")
+      const key = Path.key(head.path, { platform: "win32" })
+      for (const item of tail) {
+        expect(Path.key(item.path, { platform: "win32" })).toBe(key)
+        expect(Path.eq(head.path, item.path, { platform: "win32" })).toBe(true)
+        expect(Path.match(item.path, key, { platform: "win32" })).toBe(true)
+      }
+    })
+
+    test("matches UNC alias forms on Windows", () => {
+      const file = "\\\\server\\share\\tmp\\file.txt"
+      const key = Path.key(file, { platform: "win32" })
+      for (const input of ["//server/share/tmp/file.txt", "file://server/share/tmp/file.txt"]) {
+        expect(Path.key(input, { platform: "win32" })).toBe(key)
+        expect(Path.eq(file, input, { platform: "win32" })).toBe(true)
+        expect(Path.match(input, key, { platform: "win32" })).toBe(true)
+      }
+    })
+  })
+
+  describe("contains()", () => {
+    test("matches slash and case variants on Windows", () => {
+      expect(Path.contains("C:\\Repo", "c:/repo/src/file.ts", { platform: "win32" })).toBe(true)
+    })
+
+    test("matches all Windows alias parent and child forms", () => {
+      const dirs = alias("C:\\Users\\Dev\\tmp")
+      const files = alias("C:\\Users\\Dev\\tmp\\file.txt")
+      for (const dir of dirs) {
+        for (const file of files) {
+          expect(Path.contains(dir.path, file.path, { platform: "win32" })).toBe(true)
+        }
+      }
+    })
+
+    test("matches UNC parents across alias forms on Windows", () => {
+      const dir = "\\\\server\\share\\repo"
+      for (const file of ["//server/share/repo/src/file.ts", "file://server/share/repo/src/file.ts"]) {
+        expect(Path.contains(dir, file, { platform: "win32" })).toBe(true)
+      }
+    })
+
+    test("rejects Windows cross-drive and cross-share mixes", () => {
+      expect(Path.contains("C:\\repo", "D:\\repo\\file.ts", { platform: "win32" })).toBe(false)
+      expect(Path.contains("\\\\server\\share\\repo", "\\\\server\\other\\repo\\file.ts", { platform: "win32" })).toBe(false)
+    })
+
+    test("rejects absolute-relative path mixes", () => {
+      expect(Path.contains("/repo", "repo/src/file.ts", { platform: "linux" })).toBe(false)
+      expect(Path.contains("repo", "/repo/src/file.ts", { platform: "linux" })).toBe(false)
+    })
+  })
+
+  describe("externalGlob()", () => {
+    test("normalizes Windows directory globs", () => {
+      expect(Path.externalGlob("C:\\Users\\Dev\\tmp\\", { platform: "win32" })).toBe("C:/Users/Dev/tmp/*")
+    })
+
+    test("canonicalizes all Windows alias roots", () => {
+      for (const item of alias("C:\\Users\\Dev\\tmp")) {
+        expect(Path.externalGlob(item.path, { platform: "win32" })).toBe("C:/Users/Dev/tmp/*")
+      }
+    })
+
+    test("normalizes UNC directory globs", () => {
+      expect(Path.externalGlob("\\\\server\\share\\tmp\\", { platform: "win32" })).toBe("//server/share/tmp/*")
+    })
+  })
+
+  describe("canonical()", () => {
+    test("leaves non-path patterns alone", () => {
+      expect(Path.canonical("*", { platform: "win32" })).toBe("*")
+      expect(Path.canonical("src/*", { platform: "win32" })).toBe("src/*")
+    })
+
+    test("canonicalizes Windows alias paths to posix form", () => {
+      for (const item of alias("C:\\Users\\Dev\\tmp\\file.txt")) {
+        expect(Path.canonical(item.path, { platform: "win32" })).toBe("C:/Users/Dev/tmp/file.txt")
+        expect(Path.canonical(item.glob, { platform: "win32" })).toBe("C:/Users/Dev/tmp/file.txt/*")
+      }
+    })
+
+    test("canonicalizes UNC alias paths to posix form", () => {
+      expect(Path.canonical("\\\\server\\share\\tmp\\file.txt", { platform: "win32" })).toBe("//server/share/tmp/file.txt")
+      expect(Path.canonical("file://server/share/tmp/file.txt", { platform: "win32" })).toBe("//server/share/tmp/file.txt")
+    })
+  })
+
+  describe("guess()", () => {
+    test("detects remote Windows roots across slash variants", () => {
+      expect(Path.guess("C:\\repo\\file.ts")).toBe("win32")
+      expect(Path.guess("\\\\server\\share\\repo")).toBe("win32")
+      expect(Path.guess("/mnt/c/repo/file.ts")).toBe("win32")
+      expect(Path.guess("/srv/repo/file.ts")).toBe("linux")
+    })
+  })
+
+  describe("uri()", () => {
+    test("round-trips POSIX file URIs", () => {
+      const file = "/tmp/dir/a b.txt"
+      const uri = Path.uri(file, { platform: "linux" })
+      expect(String(uri)).toBe("file:///tmp/dir/a%20b.txt")
+      expect(String(Path.fromURI(uri, { platform: "linux" }))).toBe(file)
+    })
+
+    test("round-trips Windows file URIs", () => {
+      const file = "C:\\tmp\\dir\\a b.txt"
+      const uri = Path.uri(file, { platform: "win32" })
+      expect(String(uri)).toBe("file:///C:/tmp/dir/a%20b.txt")
+      expect(String(Path.fromURI(uri, { platform: "win32" }))).toBe(file)
+    })
+
+    test("round-trips Windows UNC file URIs", () => {
+      const file = "\\\\server\\share\\tmp\\a b.txt"
+      const uri = Path.uri(file, { platform: "win32" })
+      expect(String(uri)).toBe("file://server/share/tmp/a%20b.txt")
+      expect(String(Path.fromURI(uri, { platform: "win32" }))).toBe(file)
+    })
+
+    test("resolves repo-relative Windows paths with Windows URI rules", () => {
+      expect(String(Path.uri("src/file.ts", { cwd: "C:\\repo", platform: "windows" }))).toBe("file:///C:/repo/src/file.ts")
+    })
+
+    test("preserves undecodable URI segments", () => {
+      expect(String(Path.fromURI("file:///tmp/%ZZ/file.txt", { platform: "linux" }))).toBe("/tmp/%ZZ/file.txt")
+    })
+  })
+
+  describe("posix()", () => {
+    test("converts Windows pretty paths to forward slashes", () => {
+      expect(String(Path.posix("C:\\tmp\\dir\\file.txt", { platform: "win32" }))).toBe("C:/tmp/dir/file.txt")
+    })
+
+    test("keeps POSIX absolute paths stable", () => {
+      expect(String(Path.posix("/tmp/dir/file.txt", { platform: "linux" }))).toBe("/tmp/dir/file.txt")
+    })
+  })
+
+  describe("rel()", () => {
+    test("returns branded relative paths", () => {
+      expect(String(Path.rel("/repo", "/repo/src/file.ts", { platform: "linux" }))).toBe("src/file.ts")
+    })
+
+    test("falls back to the absolute target across Windows drives", () => {
+      expect(String(Path.rel("C:\\repo", "D:\\repo\\file.ts", { platform: "win32" }))).toBe("D:\\repo\\file.ts")
+    })
+  })
+
+  describe("repo()", () => {
+    test("normalizes repo keys to forward slashes", () => {
+      expect(String(Path.repo("src\\nested\\file.ts"))).toBe("src/nested/file.ts")
+      expect(String(Path.repo("./src//nested/"))).toBe("src/nested/")
+    })
+
+    test("preserves directory markers", () => {
+      expect(Path.repoIsDir("src\\nested\\")).toBe(true)
+      expect(Path.repoIsDir("src\\nested")).toBe(false)
+    })
+  })
+
+  describe("repoParent()", () => {
+    test("returns repo parents with root dot", () => {
+      expect(String(Path.repoParent("src\\nested\\file.ts"))).toBe("src/nested")
+      expect(String(Path.repoParent("src\\nested\\"))).toBe("src")
+      expect(String(Path.repoParent("file.ts"))).toBe(".")
+    })
+  })
+
+  describe("repoName()", () => {
+    test("returns repo basenames for files and directories", () => {
+      expect(Path.repoName("src\\nested\\file.ts")).toBe("file.ts")
+      expect(Path.repoName("src\\nested\\")).toBe("nested")
+    })
+  })
+
+  describe("repoDepth()", () => {
+    test("counts repo path segments", () => {
+      expect(Path.repoDepth("src\\nested\\file.ts")).toBe(3)
+      expect(Path.repoDepth("src\\nested\\")).toBe(2)
+      expect(Path.repoDepth(".")).toBe(0)
+    })
+  })
+
+  describe("hidden()", () => {
+    test("detects hidden segments across slash variants", () => {
+      expect(Path.hidden(".env")).toBe(true)
+      expect(Path.hidden("src/.git/config")).toBe(true)
+      expect(Path.hidden("src/.")).toBe(true)
+      expect(Path.hidden("src\\.cache\\tmp")).toBe(true)
+      expect(Path.hidden("src/visible/file.ts")).toBe(false)
+    })
+  })
+
+  describe("expand()", () => {
+    test("expands home aliases with test home semantics", () => {
+      const home = process.env.OPENCODE_TEST_HOME!
+      expect(String(Path.expand("~"))).toBe(home)
+      expect(String(Path.expand("~/repo/file.ts"))).toBe(path.join(home, "repo", "file.ts"))
+      expect(String(Path.expand("$HOME/repo/file.ts"))).toBe(path.join(home, "repo", "file.ts"))
+      expect(String(Path.expand("repo/file.ts"))).toBe("repo/file.ts")
+    })
+  })
+
+  describe("display()", () => {
+    test("shortens home paths by default", () => {
+      const home = process.env.OPENCODE_TEST_HOME!
+      expect(Path.display(path.join(home, "repo", "file.ts"))).toBe(`~${path.sep}repo${path.sep}file.ts`)
+    })
+
+    test("prefers cwd-relative output inside cwd", () => {
+      expect(Path.display("/repo/src/file.ts", { cwd: "/repo", home: "/repo", platform: "linux", relative: true })).toBe(
+        "src/file.ts",
+      )
+    })
+
+    test("can skip home shortening", () => {
+      const home = process.env.OPENCODE_TEST_HOME!
+      expect(Path.display(path.join(home, "repo", "file.ts"), { home: false })).toBe(path.join(home, "repo", "file.ts"))
+    })
+  })
+
+  describe("join()", () => {
+    test("joins child paths against an existing pretty root", () => {
+      expect(String(Path.join("/repo", "src/file.ts", { platform: "linux" }))).toBe("/repo/src/file.ts")
+    })
+  })
+
+  describe("parent()", () => {
+    test("returns the normalized parent directory", () => {
+      expect(String(Path.parent("/repo/src/file.ts", { platform: "linux" }))).toBe("/repo/src")
+    })
+  })
+
+  describe("repoFrom()", () => {
+    test("converts absolute paths back into repo paths", () => {
+      expect(String(Path.repoFrom("/repo", "/repo/src/file.ts", { platform: "linux" }))).toBe("src/file.ts")
+    })
+  })
+
+  describe("up()", () => {
+    test("walks to the bounded ancestor inclusively", () => {
+      expect(Array.from(Path.up("/repo/src/nested", { stop: "/repo", platform: "linux" }), String)).toEqual([
+        "/repo/src/nested",
+        "/repo/src",
+        "/repo",
+      ])
+    })
+
+    test("returns nothing when start is outside the bound", () => {
+      expect(Array.from(Path.up("/repo-other/src", { stop: "/repo", platform: "linux" }), String)).toEqual([])
+    })
+  })
+
+  describe("truecase()", () => {
+    test("keeps missing tails as typed on Windows", async () => {
+      if (process.platform !== "win32") return
+      await using tmp = await tmpdir()
+
+      const dir = path.join(tmp.path, "CaseDir")
+      const child = path.join(dir, "Leaf")
+      await fs.mkdir(child, { recursive: true })
+
+      const input = path.join(tmp.path.toLowerCase(), "casedir", "leaf", "Miss", "Tail.ts")
+      const result = String(await Path.truecase(input))
+
+      expect(result).toBe(path.join(tmp.path, "CaseDir", "Leaf", "Miss", "Tail.ts"))
+    })
+
+    test("preserves alias roots while true-casing Windows paths", async () => {
+      if (process.platform !== "win32") return
+      await using tmp = await tmpdir()
+
+      const real = path.join(tmp.path, "Target")
+      await fs.mkdir(path.join(real, "Leaf"), { recursive: true })
+      const alias = path.join(tmp.path, "Alias")
+      await fs.symlink(real, alias, "junction")
+
+      const input = path.join(tmp.path.toLowerCase(), "alias", "leaf")
+      const result = String(await Path.truecase(input))
+
+      expect(result).toBe(path.join(tmp.path, "Alias", "Leaf"))
+    })
+
+    test("is a no-op off Windows", async () => {
+      const file = "/tmp/test.txt"
+      expect(String(await Path.truecase(file, { platform: "linux" }))).toBe(file)
+    })
+  })
+
+  describe("physical()", () => {
+    test("resolves symlink roots while keeping missing tails", async () => {
+      await using tmp = await tmpdir()
+      const target = path.join(tmp.path, "real")
+      await fs.mkdir(target)
+      const link = path.join(tmp.path, "alias")
+      await fs.symlink(target, link, process.platform === "win32" ? "junction" : "dir")
+
+      const result = String(await Path.physical(path.join(link, "child", "file.txt")))
+      expect(result).toBe(path.join(target, "child", "file.txt"))
+    })
+  })
+
+  describe("truecaseSync()", () => {
+    test("keeps the global slash sentinel stable", () => {
+      expect(String(Path.truecaseSync("/"))).toBe("/")
+    })
+
+    test("keeps missing tails as typed on Windows", async () => {
+      if (process.platform !== "win32") return
+      await using tmp = await tmpdir()
+
+      const dir = path.join(tmp.path, "CaseDir")
+      const child = path.join(dir, "Leaf")
+      await fs.mkdir(child, { recursive: true })
+
+      const input = path.join(tmp.path.toLowerCase(), "casedir", "leaf", "Miss", "Tail.ts")
+      const result = String(Path.truecaseSync(input))
+
+      expect(result).toBe(path.join(tmp.path, "CaseDir", "Leaf", "Miss", "Tail.ts"))
+    })
+
+    test("preserves alias roots while true-casing Windows paths", async () => {
+      if (process.platform !== "win32") return
+      await using tmp = await tmpdir()
+
+      const real = path.join(tmp.path, "Target")
+      await fs.mkdir(path.join(real, "Leaf"), { recursive: true })
+      const alias = path.join(tmp.path, "Alias")
+      await fs.symlink(real, alias, "junction")
+
+      const input = path.join(tmp.path.toLowerCase(), "alias", "leaf")
+      const result = String(Path.truecaseSync(input))
+
+      expect(result).toBe(path.join(tmp.path, "Alias", "Leaf"))
+    })
+
+    test("is a no-op off Windows", () => {
+      const file = "/tmp/test.txt"
+      expect(String(Path.truecaseSync(file, { platform: "linux" }))).toBe(file)
+    })
+  })
+})
diff --git a/packages/opencode/test/path/schema.test.ts b/packages/opencode/test/path/schema.test.ts
new file mode 100644
index 000000000000..c2f2d29e8e57
--- /dev/null
+++ b/packages/opencode/test/path/schema.test.ts
@@ -0,0 +1,30 @@
+import { describe, expect, test } from "bun:test"
+import z from "zod"
+
+import { WorkspaceID } from "../../src/control-plane/schema"
+import { PrettyPath } from "../../src/path/schema"
+
+describe("runtime-safe path/id constructors", () => {
+  test("parses branded ids and rejects invalid prefixes", () => {
+    expect(String(WorkspaceID.parse("wrk_test_workspace"))).toBe("wrk_test_workspace")
+    expect(() => WorkspaceID.parse("workspace_test_workspace")).toThrow(
+      'Expected workspace id starting with "wrk"',
+    )
+  })
+
+  test("rejects relative pretty paths", () => {
+    expect(() => PrettyPath.parse("relative/path")).toThrow('Expected absolute filesystem path, received "relative/path"')
+  })
+
+  test("exports pretty path input schema to JSON schema", () => {
+    const schema = z.toJSONSchema(z.object({ path: PrettyPath.zod }))
+    expect(schema).toMatchObject({
+      type: "object",
+      properties: {
+        path: {
+          type: "string",
+        },
+      },
+    })
+  })
+})
diff --git a/packages/opencode/test/permission/next.test.ts b/packages/opencode/test/permission/next.test.ts
index 043e3257b64f..7cb54a169d67 100644
--- a/packages/opencode/test/permission/next.test.ts
+++ b/packages/opencode/test/permission/next.test.ts
@@ -1,16 +1,21 @@
 import { afterEach, test, expect } from "bun:test"
-import os from "os"
+import path from "path"
 import { Bus } from "../../src/bus"
-import { Permission } from "../../src/permission"
+import { Permission, PermissionNext } from "../../src/permission"
 import { PermissionID } from "../../src/permission/schema"
 import { Instance } from "../../src/project/instance"
+import { Path } from "../../src/path/path"
 import { tmpdir } from "../fixture/fixture"
 import { MessageID, SessionID } from "../../src/session/schema"
+import { win } from "../lib/windows-path"
 
 afterEach(async () => {
   await Instance.disposeAll()
 })
 
+const home = process.env.OPENCODE_TEST_HOME!
+const dir = path.join(home, "projects")
+
 async function rejectAll(message?: string) {
   for (const req of await Permission.list()) {
     await Permission.reply({
@@ -65,18 +70,22 @@ test("fromConfig - empty object", () => {
 })
 
 test("fromConfig - expands tilde to home directory", () => {
-  const result = Permission.fromConfig({ external_directory: { "~/projects/*": "allow" } })
-  expect(result).toEqual([{ permission: "external_directory", pattern: `${os.homedir()}/projects/*`, action: "allow" }])
+  const result = PermissionNext.fromConfig({ external_directory: { "~/projects/*": "allow" } })
+  expect(result).toEqual([
+    { permission: "external_directory", pattern: Path.canonical(path.join(dir, "*")), action: "allow" },
+  ])
 })
 
 test("fromConfig - expands $HOME to home directory", () => {
-  const result = Permission.fromConfig({ external_directory: { "$HOME/projects/*": "allow" } })
-  expect(result).toEqual([{ permission: "external_directory", pattern: `${os.homedir()}/projects/*`, action: "allow" }])
+  const result = PermissionNext.fromConfig({ external_directory: { "$HOME/projects/*": "allow" } })
+  expect(result).toEqual([
+    { permission: "external_directory", pattern: Path.canonical(path.join(dir, "*")), action: "allow" },
+  ])
 })
 
 test("fromConfig - expands $HOME without trailing slash", () => {
-  const result = Permission.fromConfig({ external_directory: { $HOME: "allow" } })
-  expect(result).toEqual([{ permission: "external_directory", pattern: os.homedir(), action: "allow" }])
+  const result = PermissionNext.fromConfig({ external_directory: { $HOME: "allow" } })
+  expect(result).toEqual([{ permission: "external_directory", pattern: Path.canonical(home), action: "allow" }])
 })
 
 test("fromConfig - does not expand tilde in middle of path", () => {
@@ -85,22 +94,97 @@ test("fromConfig - does not expand tilde in middle of path", () => {
 })
 
 test("fromConfig - expands exact tilde to home directory", () => {
-  const result = Permission.fromConfig({ external_directory: { "~": "allow" } })
-  expect(result).toEqual([{ permission: "external_directory", pattern: os.homedir(), action: "allow" }])
+  const result = PermissionNext.fromConfig({ external_directory: { "~": "allow" } })
+  expect(result).toEqual([{ permission: "external_directory", pattern: Path.canonical(home), action: "allow" }])
 })
 
 test("evaluate - matches expanded tilde pattern", () => {
-  const ruleset = Permission.fromConfig({ external_directory: { "~/projects/*": "allow" } })
-  const result = Permission.evaluate("external_directory", `${os.homedir()}/projects/file.txt`, ruleset)
+  const ruleset = PermissionNext.fromConfig({ external_directory: { "~/projects/*": "allow" } })
+  const result = PermissionNext.evaluate("external_directory", path.join(dir, "file.txt"), ruleset)
   expect(result.action).toBe("allow")
 })
 
 test("evaluate - matches expanded $HOME pattern", () => {
-  const ruleset = Permission.fromConfig({ external_directory: { "$HOME/projects/*": "allow" } })
-  const result = Permission.evaluate("external_directory", `${os.homedir()}/projects/file.txt`, ruleset)
+  const ruleset = PermissionNext.fromConfig({ external_directory: { "$HOME/projects/*": "allow" } })
+  const result = PermissionNext.evaluate("external_directory", path.join(dir, "file.txt"), ruleset)
   expect(result.action).toBe("allow")
 })
 
+test("fromConfig - canonicalizes Windows external_directory aliases", () => {
+  if (process.platform !== "win32") return
+  for (const item of win(dir)) {
+    const result = PermissionNext.fromConfig({ external_directory: { [item.glob]: "allow" } })
+    expect(result).toEqual([{ permission: "external_directory", pattern: Path.externalGlob(dir), action: "allow" }])
+  }
+})
+
+test("evaluate - matches Windows external_directory aliases across rule forms", () => {
+  if (process.platform !== "win32") return
+  const list = win(dir)
+  for (const rule of list) {
+    for (const item of list) {
+      const result = PermissionNext.evaluate("external_directory", item.glob, [
+        { permission: "external_directory", pattern: rule.glob, action: "allow" },
+      ])
+      expect(result.action).toBe("allow")
+    }
+  }
+})
+
+test("evaluate - keeps Windows external_directory matching case-insensitive", () => {
+  if (process.platform !== "win32") return
+  const result = PermissionNext.evaluate("external_directory", "c:/users/test/projects/file.txt", [
+    { permission: "external_directory", pattern: "C:/Users/Test/Projects/*", action: "allow" },
+  ])
+  expect(result.action).toBe("allow")
+})
+
+test("evaluate - keeps non-Windows external_directory matching case-sensitive", () => {
+  if (process.platform === "win32") return
+  const result = PermissionNext.evaluate("external_directory", "/users/test/projects/file.txt", [
+    { permission: "external_directory", pattern: "/Users/Test/Projects/*", action: "allow" },
+  ])
+  expect(result.action).toBe("ask")
+})
+
+test("ask - auto-allow matches Windows external_directory aliases after always", async () => {
+  if (process.platform !== "win32") return
+  const [head, tail] = win(dir)
+  await using tmp = await tmpdir({ git: true })
+  await Instance.provide({
+    directory: tmp.path,
+    fn: async () => {
+      const first = PermissionNext.ask({
+        id: PermissionID.make("per_alias1"),
+        sessionID: SessionID.make("session_alias"),
+        permission: "external_directory",
+        patterns: [head.glob],
+        metadata: {},
+        always: [head.glob],
+        ruleset: [{ permission: "external_directory", pattern: "*", action: "ask" }],
+      })
+
+      await waitForPending(1)
+      await PermissionNext.reply({
+        requestID: PermissionID.make("per_alias1"),
+        reply: "always",
+      })
+      await expect(first).resolves.toBeUndefined()
+
+      await expect(
+        PermissionNext.ask({
+          sessionID: SessionID.make("session_alias"),
+          permission: "external_directory",
+          patterns: [tail.glob],
+          metadata: {},
+          always: [],
+          ruleset: [],
+        }),
+      ).resolves.toBeUndefined()
+    },
+  })
+})
+
 // merge tests
 
 test("merge - simple concatenation", () => {
diff --git a/packages/opencode/test/project/instance.test.ts b/packages/opencode/test/project/instance.test.ts
new file mode 100644
index 000000000000..b34cd25997db
--- /dev/null
+++ b/packages/opencode/test/project/instance.test.ts
@@ -0,0 +1,92 @@
+import { afterEach, expect, test } from "bun:test"
+import fs from "fs/promises"
+import path from "path"
+
+import { Instance } from "../../src/project/instance"
+import { Log } from "../../src/util/log"
+import { resetDatabase } from "../fixture/db"
+import { tmpdir } from "../fixture/fixture"
+
+Log.init({ print: false })
+
+afterEach(async () => {
+  await Instance.disposeAll()
+  await resetDatabase()
+})
+
+async function link(dir: string) {
+  const alias = path.join(path.dirname(dir), path.basename(dir) + "-link")
+  await fs.rm(alias, { recursive: true, force: true }).catch(() => undefined)
+  await fs.symlink(dir, alias, process.platform === "win32" ? "junction" : "dir")
+  return alias
+}
+
+test("Instance keeps alias directories and reload disposes stored state", async () => {
+  await using tmp = await tmpdir({ git: true })
+  const alias = await link(tmp.path)
+  const seen: string[] = []
+  let n = 0
+  const state = Instance.state(
+    () => ({ n: ++n, dir: Instance.directory }),
+    async (value) => {
+      seen.push(value.dir)
+    },
+  )
+
+  try {
+    const a = await Instance.provide({
+      directory: `${alias}${path.sep}work${path.sep}..`,
+      fn: async () => state(),
+    })
+
+    expect(String(a.dir)).toBe(alias)
+
+    await Instance.reload({
+      directory: `${alias}${path.sep}.${path.sep}`,
+    })
+
+    const b = await Instance.provide({
+      directory: alias,
+      fn: async () => state(),
+    })
+
+    expect(b).not.toBe(a)
+    expect(String(b.dir)).toBe(alias)
+    expect(seen.map(String)).toEqual([alias])
+  } finally {
+    await fs.rm(alias, { recursive: true, force: true }).catch(() => undefined)
+  }
+})
+
+test("Instance dedupes concurrent equivalent directories by key", async () => {
+  await using tmp = await tmpdir({ git: true })
+  const alias = await link(tmp.path)
+  let n = 0
+
+  try {
+    const [a, b] = await Promise.all([
+      Instance.provide({
+        directory: `${alias}${path.sep}work${path.sep}..`,
+        init: async () => {
+          n += 1
+          await Bun.sleep(10)
+        },
+        fn: async () => Instance.directory,
+      }),
+      Instance.provide({
+        directory: `${alias}${path.sep}.${path.sep}`,
+        init: async () => {
+          n += 1
+          await Bun.sleep(10)
+        },
+        fn: async () => Instance.directory,
+      }),
+    ])
+
+    expect(String(a)).toBe(alias)
+    expect(String(b)).toBe(alias)
+    expect(n).toBe(1)
+  } finally {
+    await fs.rm(alias, { recursive: true, force: true }).catch(() => undefined)
+  }
+})
diff --git a/packages/opencode/test/project/migrate-global.test.ts b/packages/opencode/test/project/migrate-global.test.ts
index b66653f7005d..a2c7c406f4b8 100644
--- a/packages/opencode/test/project/migrate-global.test.ts
+++ b/packages/opencode/test/project/migrate-global.test.ts
@@ -5,9 +5,12 @@ import { SessionTable } from "../../src/session/session.sql"
 import { ProjectTable } from "../../src/project/project.sql"
 import { ProjectID } from "../../src/project/schema"
 import { SessionID } from "../../src/session/schema"
+import { PrettyPath } from "../../src/path/schema"
 import { Log } from "../../src/util/log"
+import { PathMigration } from "../../src/path/migrate"
 import { $ } from "bun"
 import { tmpdir } from "../fixture/fixture"
+import path from "path"
 
 Log.init({ print: false })
 
@@ -24,7 +27,7 @@ function seed(opts: { id: SessionID; dir: string; project: ProjectID }) {
         id: opts.id,
         project_id: opts.project,
         slug: opts.id,
-        directory: opts.dir,
+        directory: PrettyPath.make(opts.dir),
         title: "test",
         version: "0.0.0-test",
         time_created: now,
@@ -38,12 +41,12 @@ function ensureGlobal() {
   Database.use((db) =>
     db
       .insert(ProjectTable)
-      .values({
-        id: ProjectID.global,
-        worktree: "/",
-        time_created: Date.now(),
-        time_updated: Date.now(),
-        sandboxes: [],
+        .values({
+          id: ProjectID.global,
+          worktree: PrettyPath.make("/"),
+          time_created: Date.now(),
+          time_updated: Date.now(),
+          sandboxes: [],
       })
       .onConflictDoNothing()
       .run(),
@@ -119,6 +122,33 @@ describe("migrateFromGlobal", () => {
     expect(row!.project_id).toBe(ProjectID.global)
   })
 
+  test("migrates sessions after path normalization rewrites equivalent directories", async () => {
+    await using tmp = await tmpdir()
+    await $`git init`.cwd(tmp.path).quiet()
+    await $`git config user.name "Test"`.cwd(tmp.path).quiet()
+    await $`git config user.email "test@opencode.test"`.cwd(tmp.path).quiet()
+    const { project: pre } = await Project.fromDirectory(tmp.path)
+    expect(pre.id).toBe(ProjectID.global)
+
+    const id = uid()
+    seed({
+      id,
+      dir: `${tmp.path}${path.sep}work${path.sep}..`,
+      project: ProjectID.global,
+    })
+
+    await PathMigration.run({ force: true, marker: path.join(tmp.path, "path-migration.json") })
+
+    await $`git commit --allow-empty -m "root"`.cwd(tmp.path).quiet()
+
+    const { project } = await Project.fromDirectory(tmp.path)
+    expect(project.id).not.toBe(ProjectID.global)
+
+    const row = Database.use((db) => db.select().from(SessionTable).where(eq(SessionTable.id, id)).get())
+    expect(row).toBeDefined()
+    expect(row!.project_id).toBe(project.id)
+  })
+
   test("does not steal sessions from unrelated directories", async () => {
     await using tmp = await tmpdir({ git: true })
     const { project } = await Project.fromDirectory(tmp.path)
diff --git a/packages/opencode/test/project/project.test.ts b/packages/opencode/test/project/project.test.ts
index a71fe0528f02..853ab83b220b 100644
--- a/packages/opencode/test/project/project.test.ts
+++ b/packages/opencode/test/project/project.test.ts
@@ -77,7 +77,7 @@ describe("Project.fromDirectory", () => {
     expect(project).toBeDefined()
     expect(project.id).toBe(ProjectID.global)
     expect(project.vcs).toBe("git")
-    expect(project.worktree).toBe(tmp.path)
+    expect(String(project.worktree)).toBe(tmp.path)
 
     const opencodeFile = path.join(tmp.path, ".git", "opencode")
     const fileExists = await Filesystem.exists(opencodeFile)
@@ -93,13 +93,24 @@ describe("Project.fromDirectory", () => {
     expect(project).toBeDefined()
     expect(project.id).not.toBe(ProjectID.global)
     expect(project.vcs).toBe("git")
-    expect(project.worktree).toBe(tmp.path)
+    expect(String(project.worktree)).toBe(tmp.path)
 
     const opencodeFile = path.join(tmp.path, ".git", "opencode")
     const fileExists = await Filesystem.exists(opencodeFile)
     expect(fileExists).toBe(true)
   })
 
+  test("truecases authoritative git paths before persisting", async () => {
+    if (process.platform !== "win32") return
+    const p = await loadProject()
+    await using tmp = await tmpdir({ git: true })
+
+    const { project, sandbox } = await p.fromDirectory(tmp.path.toUpperCase())
+
+    expect(String(project.worktree)).toBe(tmp.path)
+    expect(String(sandbox)).toBe(tmp.path)
+  })
+
   test("keeps git vcs when rev-list exits non-zero with empty output", async () => {
     const p = await loadProject()
     await using tmp = await tmpdir()
@@ -109,7 +120,7 @@ describe("Project.fromDirectory", () => {
       const { project } = await p.fromDirectory(tmp.path)
       expect(project.vcs).toBe("git")
       expect(project.id).toBe(ProjectID.global)
-      expect(project.worktree).toBe(tmp.path)
+      expect(String(project.worktree)).toBe(tmp.path)
     })
   })
 
@@ -120,8 +131,8 @@ describe("Project.fromDirectory", () => {
     await withMode("top-fail", async () => {
       const { project, sandbox } = await p.fromDirectory(tmp.path)
       expect(project.vcs).toBe("git")
-      expect(project.worktree).toBe(tmp.path)
-      expect(sandbox).toBe(tmp.path)
+      expect(String(project.worktree)).toBe(tmp.path)
+      expect(String(sandbox)).toBe(tmp.path)
     })
   })
 
@@ -132,8 +143,8 @@ describe("Project.fromDirectory", () => {
     await withMode("common-dir-fail", async () => {
       const { project, sandbox } = await p.fromDirectory(tmp.path)
       expect(project.vcs).toBe("git")
-      expect(project.worktree).toBe(tmp.path)
-      expect(sandbox).toBe(tmp.path)
+      expect(String(project.worktree)).toBe(tmp.path)
+      expect(String(sandbox)).toBe(tmp.path)
     })
   })
 })
@@ -145,9 +156,9 @@ describe("Project.fromDirectory with worktrees", () => {
 
     const { project, sandbox } = await p.fromDirectory(tmp.path)
 
-    expect(project.worktree).toBe(tmp.path)
-    expect(sandbox).toBe(tmp.path)
-    expect(project.sandboxes).not.toContain(tmp.path)
+    expect(String(project.worktree)).toBe(tmp.path)
+    expect(String(sandbox)).toBe(tmp.path)
+    expect(project.sandboxes.map(String)).not.toContain(tmp.path)
   })
 
   test("should set worktree to root when called from a worktree", async () => {
@@ -160,10 +171,10 @@ describe("Project.fromDirectory with worktrees", () => {
 
       const { project, sandbox } = await p.fromDirectory(worktreePath)
 
-      expect(project.worktree).toBe(tmp.path)
-      expect(sandbox).toBe(worktreePath)
-      expect(project.sandboxes).toContain(worktreePath)
-      expect(project.sandboxes).not.toContain(tmp.path)
+      expect(String(project.worktree)).toBe(tmp.path)
+      expect(String(sandbox)).toBe(worktreePath)
+      expect(project.sandboxes.map(String)).toContain(worktreePath)
+      expect(project.sandboxes.map(String)).not.toContain(tmp.path)
     } finally {
       await $`git worktree remove ${worktreePath}`
         .cwd(tmp.path)
@@ -231,10 +242,10 @@ describe("Project.fromDirectory with worktrees", () => {
       await p.fromDirectory(worktree1)
       const { project } = await p.fromDirectory(worktree2)
 
-      expect(project.worktree).toBe(tmp.path)
-      expect(project.sandboxes).toContain(worktree1)
-      expect(project.sandboxes).toContain(worktree2)
-      expect(project.sandboxes).not.toContain(tmp.path)
+      expect(String(project.worktree)).toBe(tmp.path)
+      expect(project.sandboxes.map(String)).toContain(worktree1)
+      expect(project.sandboxes.map(String)).toContain(worktree2)
+      expect(project.sandboxes.map(String)).not.toContain(tmp.path)
     } finally {
       await $`git worktree remove ${worktree1}`
         .cwd(tmp.path)
@@ -393,3 +404,29 @@ describe("Project.update", () => {
     expect(updated.commands?.start).toBe("make start")
   })
 })
+
+describe("Project sandbox paths", () => {
+  test("dedupes equivalent sandbox paths", async () => {
+    await using tmp = await tmpdir({ git: true })
+    const { project } = await Project.fromDirectory(tmp.path)
+    const dir = path.join(tmp.path, "sandbox")
+    await Filesystem.write(path.join(dir, ".keep"), "ok")
+
+    await Project.addSandbox(project.id, dir)
+    const updated = await Project.addSandbox(project.id, `${dir}${path.sep}child${path.sep}..`)
+
+    expect(updated.sandboxes.filter((item) => item === dir)).toHaveLength(1)
+  })
+
+  test("removes equivalent sandbox paths", async () => {
+    await using tmp = await tmpdir({ git: true })
+    const { project } = await Project.fromDirectory(tmp.path)
+    const dir = path.join(tmp.path, "sandbox")
+    await Filesystem.write(path.join(dir, ".keep"), "ok")
+
+    await Project.addSandbox(project.id, dir)
+    const updated = await Project.removeSandbox(project.id, `${dir}${path.sep}child${path.sep}..`)
+
+    expect(updated.sandboxes.map(String)).not.toContain(dir)
+  })
+})
diff --git a/packages/opencode/test/server/global-session-list.test.ts b/packages/opencode/test/server/global-session-list.test.ts
index 05d6de04b1b1..342dec43f51f 100644
--- a/packages/opencode/test/server/global-session-list.test.ts
+++ b/packages/opencode/test/server/global-session-list.test.ts
@@ -1,4 +1,5 @@
 import { describe, expect, test } from "bun:test"
+import path from "path"
 import { Instance } from "../../src/project/instance"
 import { Project } from "../../src/project/project"
 import { Session } from "../../src/session"
@@ -86,4 +87,24 @@ describe("Session.listGlobal", () => {
     expect(ids).toContain(first.id)
     expect(ids).not.toContain(second.id)
   })
+
+  test("filters by equivalent pretty paths", async () => {
+    await using tmp = await tmpdir({ git: true })
+    await using tmp2 = await tmpdir({ git: true })
+
+    const first = await Instance.provide({
+      directory: tmp.path,
+      fn: async () => Session.create({ title: "global-pretty-match" }),
+    })
+    const second = await Instance.provide({
+      directory: tmp2.path,
+      fn: async () => Session.create({ title: "global-pretty-other" }),
+    })
+
+    const sessions = [...Session.listGlobal({ directory: `${tmp.path}${path.sep}work${path.sep}..`, limit: 200 })]
+    const ids = sessions.map((session) => session.id)
+
+    expect(ids).toContain(first.id)
+    expect(ids).not.toContain(second.id)
+  })
 })
diff --git a/packages/opencode/test/server/path-alias.test.ts b/packages/opencode/test/server/path-alias.test.ts
new file mode 100644
index 000000000000..511dc36c2128
--- /dev/null
+++ b/packages/opencode/test/server/path-alias.test.ts
@@ -0,0 +1,124 @@
+import { afterEach, expect, mock, test } from "bun:test"
+import fs from "fs/promises"
+import path from "path"
+
+import { Instance } from "../../src/project/instance"
+import { Log } from "../../src/util/log"
+import { resetDatabase } from "../fixture/db"
+import { tmpdir } from "../fixture/fixture"
+
+mock.module("../../src/project/bootstrap", () => ({
+  InstanceBootstrap: async () => {},
+}))
+
+const { Server } = await import("../../src/server/server")
+
+Log.init({ print: false })
+
+afterEach(async () => {
+  await Instance.disposeAll()
+  await resetDatabase()
+})
+
+async function link(dir: string) {
+  const alias = path.join(path.dirname(dir), path.basename(dir) + "-link")
+  await fs.rm(alias, { recursive: true, force: true }).catch(() => undefined)
+  await fs.symlink(dir, alias, process.platform === "win32" ? "junction" : "dir")
+  return alias
+}
+
+test("server ingress keeps alias directories", async () => {
+  await using tmp = await tmpdir({ git: true })
+  const alias = await link(tmp.path)
+
+  try {
+    const app = Server.createApp({})
+    const response = await app.request("/path", {
+      headers: {
+        "x-opencode-directory": `${alias}${path.sep}work${path.sep}..`,
+      },
+    })
+
+    expect(response.status).toBe(200)
+    expect(await response.json()).toMatchObject({
+      os: process.platform === "win32" ? "windows" : process.platform === "darwin" ? "macos" : "linux",
+      directory: alias,
+    })
+  } finally {
+    await fs.rm(alias, { recursive: true, force: true }).catch(() => undefined)
+  }
+})
+
+test("server ingress accepts literal percent directories", async () => {
+  await using tmp = await tmpdir()
+  const dir = path.join(tmp.path, "100% ready")
+  await fs.mkdir(dir)
+
+  const app = Server.createApp({})
+  const response = await app.request("/path", {
+    headers: {
+      "x-opencode-directory": dir,
+    },
+  })
+
+  expect(response.status).toBe(200)
+  expect(await response.json()).toMatchObject({
+    directory: dir,
+  })
+})
+
+test("server ingress decodes encoded directory headers once", async () => {
+  await using tmp = await tmpdir()
+  const dir = path.join(tmp.path, "100% ready")
+  await fs.mkdir(dir)
+
+  const app = Server.createApp({})
+  const response = await app.request("/path", {
+    headers: {
+      "x-opencode-directory": encodeURIComponent(dir),
+    },
+  })
+
+  expect(response.status).toBe(200)
+  expect(await response.json()).toMatchObject({
+    directory: dir,
+  })
+})
+
+test("server ingress keeps query directory behavior", async () => {
+  await using tmp = await tmpdir()
+  const dir = path.join(tmp.path, "100% ready")
+  await fs.mkdir(dir)
+
+  const app = Server.createApp({})
+  const response = await app.request(`/path?directory=${encodeURIComponent(dir)}`)
+
+  expect(response.status).toBe(200)
+  expect(await response.json()).toMatchObject({
+    directory: dir,
+  })
+})
+
+test("server ingress rejects invalid workspace ids", async () => {
+  const app = Server.createApp({})
+  const response = await app.request("/path", {
+    headers: {
+      "x-opencode-workspace": "workspace_test",
+    },
+  })
+
+  expect(response.status).toBe(400)
+  expect(await response.text()).toContain('Expected workspace id starting with "wrk"')
+})
+
+test("server ingress rejects invalid encoded directories", async () => {
+  const app = Server.createApp({})
+  const response = await app.request("/path", {
+    headers: {
+      "x-opencode-directory": "%E0%A4%A",
+    },
+  })
+
+  expect(response.status).toBe(400)
+  expect(await response.text()).toContain("Invalid percent-encoding in directory parameter")
+})
diff --git a/packages/opencode/test/server/session-list.test.ts b/packages/opencode/test/server/session-list.test.ts
index 675a89011f96..5d15529a576c 100644
--- a/packages/opencode/test/server/session-list.test.ts
+++ b/packages/opencode/test/server/session-list.test.ts
@@ -2,6 +2,9 @@ import { describe, expect, test } from "bun:test"
 import path from "path"
 import { Instance } from "../../src/project/instance"
 import { Session } from "../../src/session"
+import { Database, eq } from "../../src/storage/db"
+import { SessionTable } from "../../src/session/session.sql"
+import { PrettyPath } from "../../src/path/schema"
 import { Log } from "../../src/util/log"
 
 const projectRoot = path.join(__dirname, "../..")
@@ -29,6 +32,47 @@ describe("Session.list", () => {
     })
   })
 
+  test("filters by equivalent pretty paths", async () => {
+    await Instance.provide({
+      directory: projectRoot,
+      fn: async () => {
+        const first = await Session.create({})
+
+        const otherDir = path.join(projectRoot, "..", "__session_list_equivalent_other")
+        const second = await Instance.provide({
+          directory: otherDir,
+          fn: async () => Session.create({}),
+        })
+
+        const sessions = [...Session.list({ directory: `${projectRoot}${path.sep}work${path.sep}..` })]
+        const ids = sessions.map((s) => s.id)
+
+        expect(ids).toContain(first.id)
+        expect(ids).not.toContain(second.id)
+      },
+    })
+  })
+
+  test("reads stored directories back in true case", async () => {
+    if (process.platform !== "win32") return
+    await Instance.provide({
+      directory: projectRoot,
+      fn: async () => {
+        const session = await Session.create({})
+        Database.use((db) =>
+          db
+            .update(SessionTable)
+            .set({ directory: PrettyPath.make(projectRoot.toUpperCase()) })
+            .where(eq(SessionTable.id, session.id))
+            .run(),
+        )
+
+        const result = await Session.get(session.id)
+        expect(String(result.directory)).toBe(projectRoot)
+      },
+    })
+  })
+
   test("filters root sessions", async () => {
     await Instance.provide({
       directory: projectRoot,
diff --git a/packages/opencode/test/session/instruction.test.ts b/packages/opencode/test/session/instruction.test.ts
index e0bf94a9500d..841e18adcca4 100644
--- a/packages/opencode/test/session/instruction.test.ts
+++ b/packages/opencode/test/session/instruction.test.ts
@@ -1,9 +1,12 @@
 import { afterEach, beforeEach, describe, expect, test } from "bun:test"
+import fs from "fs/promises"
 import path from "path"
 import { InstructionPrompt } from "../../src/session/instruction"
 import { Instance } from "../../src/project/instance"
 import { Global } from "../../src/global"
 import { tmpdir } from "../fixture/fixture"
+import { Path } from "../../src/path/path"
+import { win as alias } from "../lib/windows-path"
 
 describe("InstructionPrompt.resolve", () => {
   test("returns empty when AGENTS.md is at project root (already in systemPaths)", async () => {
@@ -17,9 +20,9 @@ describe("InstructionPrompt.resolve", () => {
       directory: tmp.path,
       fn: async () => {
         const system = await InstructionPrompt.systemPaths()
-        expect(system.has(path.join(tmp.path, "AGENTS.md"))).toBe(true)
+        expect(system.has(Path.pretty(path.join(tmp.path, "AGENTS.md")))).toBe(true)
 
-        const results = await InstructionPrompt.resolve([], path.join(tmp.path, "src", "file.ts"), "test-message-1")
+        const results = await InstructionPrompt.resolve([], Path.pretty(path.join(tmp.path, "src", "file.ts")), "test-message-1")
         expect(results).toEqual([])
       },
     })
@@ -36,15 +39,15 @@ describe("InstructionPrompt.resolve", () => {
       directory: tmp.path,
       fn: async () => {
         const system = await InstructionPrompt.systemPaths()
-        expect(system.has(path.join(tmp.path, "subdir", "AGENTS.md"))).toBe(false)
+        expect(system.has(Path.pretty(path.join(tmp.path, "subdir", "AGENTS.md")))).toBe(false)
 
         const results = await InstructionPrompt.resolve(
           [],
-          path.join(tmp.path, "subdir", "nested", "file.ts"),
+          Path.pretty(path.join(tmp.path, "subdir", "nested", "file.ts")),
           "test-message-2",
         )
         expect(results.length).toBe(1)
-        expect(results[0].filepath).toBe(path.join(tmp.path, "subdir", "AGENTS.md"))
+        expect(String(results[0].filepath)).toBe(path.join(tmp.path, "subdir", "AGENTS.md"))
       },
     })
   })
@@ -61,13 +64,34 @@ describe("InstructionPrompt.resolve", () => {
       fn: async () => {
         const filepath = path.join(tmp.path, "subdir", "AGENTS.md")
         const system = await InstructionPrompt.systemPaths()
-        expect(system.has(filepath)).toBe(false)
+        expect(system.has(Path.pretty(filepath))).toBe(false)
 
-        const results = await InstructionPrompt.resolve([], filepath, "test-message-2")
+        const results = await InstructionPrompt.resolve([], Path.pretty(filepath), "test-message-2")
         expect(results).toEqual([])
       },
     })
   })
+
+  test("ignores AGENTS.md in prefix-collision siblings outside project", async () => {
+    await using tmp = await tmpdir()
+    const other = tmp.path + "-other"
+
+    try {
+      await fs.mkdir(path.join(other, "src"), { recursive: true })
+      await Bun.write(path.join(other, "AGENTS.md"), "# Other Instructions")
+      await Bun.write(path.join(other, "src", "file.ts"), "const x = 1")
+
+      await Instance.provide({
+        directory: tmp.path,
+        fn: async () => {
+          const results = await InstructionPrompt.resolve([], Path.pretty(path.join(other, "src", "file.ts")), "test-message-3")
+          expect(results).toEqual([])
+        },
+      })
+    } finally {
+      await fs.rm(other, { recursive: true, force: true })
+    }
+  })
 })
 
 describe("InstructionPrompt.systemPaths OPENCODE_CONFIG_DIR", () => {
@@ -107,8 +131,8 @@ describe("InstructionPrompt.systemPaths OPENCODE_CONFIG_DIR", () => {
         directory: projectTmp.path,
         fn: async () => {
           const paths = await InstructionPrompt.systemPaths()
-          expect(paths.has(path.join(profileTmp.path, "AGENTS.md"))).toBe(true)
-          expect(paths.has(path.join(globalTmp.path, "AGENTS.md"))).toBe(false)
+          expect(paths.has(Path.pretty(path.join(profileTmp.path, "AGENTS.md")))).toBe(true)
+          expect(paths.has(Path.pretty(path.join(globalTmp.path, "AGENTS.md")))).toBe(false)
         },
       })
     } finally {
@@ -134,8 +158,8 @@ describe("InstructionPrompt.systemPaths OPENCODE_CONFIG_DIR", () => {
         directory: projectTmp.path,
         fn: async () => {
           const paths = await InstructionPrompt.systemPaths()
-          expect(paths.has(path.join(profileTmp.path, "AGENTS.md"))).toBe(false)
-          expect(paths.has(path.join(globalTmp.path, "AGENTS.md"))).toBe(true)
+          expect(paths.has(Path.pretty(path.join(profileTmp.path, "AGENTS.md")))).toBe(false)
+          expect(paths.has(Path.pretty(path.join(globalTmp.path, "AGENTS.md")))).toBe(true)
         },
       })
     } finally {
@@ -160,7 +184,7 @@ describe("InstructionPrompt.systemPaths OPENCODE_CONFIG_DIR", () => {
         directory: projectTmp.path,
         fn: async () => {
           const paths = await InstructionPrompt.systemPaths()
-          expect(paths.has(path.join(globalTmp.path, "AGENTS.md"))).toBe(true)
+          expect(paths.has(Path.pretty(path.join(globalTmp.path, "AGENTS.md")))).toBe(true)
         },
       })
     } finally {
@@ -168,3 +192,55 @@ describe("InstructionPrompt.systemPaths OPENCODE_CONFIG_DIR", () => {
     }
   })
 })
+
+describe("InstructionPrompt.systemPaths instruction boundaries", () => {
+  test("resolves file URI instructions through Path", async () => {
+    await using tmp = await tmpdir({
+      init: async (dir) => {
+        const file = path.join(dir, "rules.md")
+        await Bun.write(file, "# Rules")
+        await Bun.write(
+          path.join(dir, "opencode.json"),
+          JSON.stringify({
+            $schema: "https://opencode.ai/config.json",
+            instructions: [String(Path.uri(file))],
+          }),
+        )
+      },
+    })
+
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const paths = await InstructionPrompt.systemPaths()
+        expect(paths.has(Path.pretty(path.join(tmp.path, "rules.md")))).toBe(true)
+      },
+    })
+  })
+
+  test("resolves Windows alias instructions through Path", async () => {
+    if (process.platform !== "win32") return
+
+    await using tmp = await tmpdir({
+      init: async (dir) => {
+        const file = path.join(dir, "rules.md")
+        await Bun.write(file, "# Rules")
+        await Bun.write(
+          path.join(dir, "opencode.json"),
+          JSON.stringify({
+            $schema: "https://opencode.ai/config.json",
+            instructions: [alias(file).find((item) => item.name === "git")!.path],
+          }),
+        )
+      },
+    })
+
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const paths = await InstructionPrompt.systemPaths()
+        expect(paths.has(Path.pretty(path.join(tmp.path, "rules.md")))).toBe(true)
+      },
+    })
+  })
+})
diff --git a/packages/opencode/test/session/message-v2.test.ts b/packages/opencode/test/session/message-v2.test.ts
index 0d5b89730a98..918b8e7cd8f3 100644
--- a/packages/opencode/test/session/message-v2.test.ts
+++ b/packages/opencode/test/session/message-v2.test.ts
@@ -1,6 +1,8 @@
 import { describe, expect, test } from "bun:test"
+import path from "path"
 import { APICallError } from "ai"
 import { MessageV2 } from "../../src/session/message-v2"
+import { Path } from "../../src/path/path"
 import type { Provider } from "../../src/provider/provider"
 import { ModelID, ProviderID } from "../../src/provider/schema"
 import { SessionID, MessageID, PartID } from "../../src/session/schema"
@@ -108,6 +110,46 @@ function basePart(messageID: string, id: string) {
 }
 
 describe("session.message-v2.toModelMessage", () => {
+  test("normalizes assistant path fields at the schema boundary", () => {
+    const cwd = path.join(process.cwd(), ".")
+    const root = path.join(process.cwd(), "..", path.basename(process.cwd()))
+    const parsed = MessageV2.Info.parse({
+      ...assistantInfo("msg_assistant", "msg_parent"),
+      path: {
+        cwd,
+        root,
+      },
+    })
+
+    expect(parsed.role).toBe("assistant")
+    if (parsed.role !== "assistant") return
+    expect(parsed.path.cwd).toBe(Path.pretty(cwd))
+    expect(parsed.path.root).toBe(Path.pretty(root))
+  })
+
+  test("normalizes file source paths at the schema boundary", () => {
+    const sourcePath = path.join(process.cwd(), ".")
+    const parsed = MessageV2.Part.parse({
+      ...basePart("msg_user", "prt_file"),
+      type: "file",
+      mime: "image/png",
+      url: "data:image/png;base64,Zm9v",
+      source: {
+        type: "file",
+        path: sourcePath,
+        text: {
+          value: "hello",
+          start: 1,
+          end: 1,
+        },
+      },
+    })
+
+    expect(parsed.type).toBe("file")
+    if (parsed.type !== "file" || !parsed.source || parsed.source.type !== "file") return
+    expect(parsed.source.path).toBe(Path.pretty(sourcePath))
+  })
+
   test("filters out messages with no parts", () => {
     const input: MessageV2.WithParts[] = [
       {
diff --git a/packages/opencode/test/session/prompt.test.ts b/packages/opencode/test/session/prompt.test.ts
index 3986271dab96..e0a2df3b6548 100644
--- a/packages/opencode/test/session/prompt.test.ts
+++ b/packages/opencode/test/session/prompt.test.ts
@@ -1,6 +1,8 @@
 import path from "path"
 import { describe, expect, test } from "bun:test"
-import { fileURLToPath } from "url"
+import { fileURLToPath, pathToFileURL } from "url"
+import { Bus } from "../../src/bus"
+import { Permission } from "../../src/permission"
 import { Instance } from "../../src/project/instance"
 import { ModelID, ProviderID } from "../../src/provider/schema"
 import { Session } from "../../src/session"
@@ -8,6 +10,8 @@ import { MessageV2 } from "../../src/session/message-v2"
 import { SessionPrompt } from "../../src/session/prompt"
 import { Log } from "../../src/util/log"
 import { tmpdir } from "../fixture/fixture"
+import { Path } from "../../src/path/path"
+import { win as alias } from "../lib/windows-path"
 
 Log.init({ print: false })
 
@@ -146,6 +150,199 @@ describe("session.prompt special characters", () => {
       },
     })
   })
+
+  test("resolves home-relative prompt file references with test home semantics", async () => {
+    const home = process.env.OPENCODE_TEST_HOME!
+    await Bun.write(path.join(home, "prompt-home.txt"), "home content\n")
+
+    await using tmp = await tmpdir({ git: true })
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const parts = await SessionPrompt.resolvePromptParts("Read @~/prompt-home.txt")
+        const file = parts.find((part) => part.type === "file")
+        if (!file || file.type !== "file") throw new Error("expected file part")
+
+        expect(file.filename).toBe("~/prompt-home.txt")
+        expect(fileURLToPath(file.url)).toBe(path.join(home, "prompt-home.txt"))
+      },
+    })
+  })
+
+  test("resolves file URI prompt file references through Path", async () => {
+    await using tmp = await tmpdir({
+      git: true,
+      init: async (dir) => {
+        await Bun.write(path.join(dir, "prompt-uri.txt"), "uri content\n")
+      },
+    })
+
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const file = path.join(tmp.path, "prompt-uri.txt")
+        const parts = await SessionPrompt.resolvePromptParts(`Read @${Path.uri(file)}`)
+        const item = parts.find((part) => part.type === "file")
+        if (!item || item.type !== "file") throw new Error("expected file part")
+
+        expect(fileURLToPath(item.url)).toBe(file)
+      },
+    })
+  })
+
+  test("resolves Windows alias prompt file references through Path", async () => {
+    if (process.platform !== "win32") return
+
+    await using tmp = await tmpdir({
+      git: true,
+      init: async (dir) => {
+        await Bun.write(path.join(dir, "prompt-alias.txt"), "alias content\n")
+      },
+    })
+
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const file = path.join(tmp.path, "prompt-alias.txt")
+        const ref = alias(file).find((item) => item.name === "git")!.path
+        const parts = await SessionPrompt.resolvePromptParts(`Read @${ref}`)
+        const item = parts.find((part) => part.type === "file")
+        if (!item || item.type !== "file") throw new Error("expected file part")
+
+        expect(fileURLToPath(item.url)).toBe(file)
+      },
+    })
+  })
+})
+
+describe("session.prompt local file permissions", () => {
+  test("asks for read permission before synthetic file reads", async () => {
+    await using tmp = await tmpdir({
+      git: true,
+      init: async (dir) => {
+        await Bun.write(path.join(dir, "note.txt"), "classified\n")
+      },
+      config: {
+        agent: {
+          build: {
+            model: "openai/gpt-5.2",
+            permission: {
+              read: {
+                "*": "ask",
+              },
+            },
+          },
+        },
+      },
+    })
+
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const session = await Session.create({})
+        const seen: Permission.Request[] = []
+        const unsub = Bus.subscribe(Permission.Event.Asked, (event) => {
+          seen.push(event.properties)
+          void Permission.reply({
+            requestID: event.properties.id,
+            reply: "once",
+          })
+        })
+
+        try {
+          const msg = await SessionPrompt.prompt({
+            sessionID: session.id,
+            agent: "build",
+            noReply: true,
+            parts: [
+              {
+                type: "file",
+                mime: "text/plain",
+                url: pathToFileURL(path.join(tmp.path, "note.txt")).href,
+                filename: "note.txt",
+              },
+            ],
+          })
+
+          if (msg.info.role !== "user") throw new Error("expected user message")
+
+          const req = seen.find((item) => item.permission === "read")
+          expect(req).toBeDefined()
+          expect(req!.patterns).toEqual([path.join(tmp.path, "note.txt")])
+          expect(msg.parts.some((part) => part.type === "text" && part.text.includes("classified"))).toBe(true)
+        } finally {
+          unsub()
+          await Session.remove(session.id)
+        }
+      },
+    })
+  })
+
+  test("asks for external_directory permission before synthetic directory reads", async () => {
+    await using outer = await tmpdir({
+      init: async (dir) => {
+        await Bun.write(path.join(dir, "shared", "a.txt"), "a\n")
+      },
+    })
+    await using tmp = await tmpdir({
+      git: true,
+      config: {
+        agent: {
+          build: {
+            model: "openai/gpt-5.2",
+            permission: {
+              external_directory: {
+                "*": "ask",
+              },
+              read: "allow",
+            },
+          },
+        },
+      },
+    })
+
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const session = await Session.create({})
+        const seen: Permission.Request[] = []
+        const unsub = Bus.subscribe(Permission.Event.Asked, (event) => {
+          seen.push(event.properties)
+          void Permission.reply({
+            requestID: event.properties.id,
+            reply: "once",
+          })
+        })
+
+        try {
+          const dir = path.join(outer.path, "shared")
+          const msg = await SessionPrompt.prompt({
+            sessionID: session.id,
+            agent: "build",
+            noReply: true,
+            parts: [
+              {
+                type: "file",
+                mime: "application/x-directory",
+                url: pathToFileURL(dir).href,
+                filename: "shared",
+              },
+            ],
+          })
+
+          if (msg.info.role !== "user") throw new Error("expected user message")
+
+          const req = seen.find((item) => item.permission === "external_directory")
+          expect(req).toBeDefined()
+          expect(req!.patterns).toEqual([path.join(dir, "*").replaceAll("\\", "/")])
+          expect(msg.parts.some((part) => part.type === "text" && part.text.includes("a.txt"))).toBe(true)
+        } finally {
+          unsub()
+          await Session.remove(session.id)
+        }
+      },
+    })
+  })
 })
 
 describe("session.prompt agent variant", () => {
diff --git a/packages/opencode/test/session/revert-compact.test.ts b/packages/opencode/test/session/revert-compact.test.ts
index fb37a3a8dca1..d002ee4eda30 100644
--- a/packages/opencode/test/session/revert-compact.test.ts
+++ b/packages/opencode/test/session/revert-compact.test.ts
@@ -5,6 +5,7 @@ import { ModelID, ProviderID } from "../../src/provider/schema"
 import { SessionRevert } from "../../src/session/revert"
 import { SessionCompaction } from "../../src/session/compaction"
 import { MessageV2 } from "../../src/session/message-v2"
+import { Path } from "../../src/path/path"
 import { Log } from "../../src/util/log"
 import { Instance } from "../../src/project/instance"
 import { MessageID, PartID } from "../../src/session/schema"
@@ -55,8 +56,8 @@ describe("revert + compact workflow", () => {
           mode: "default",
           agent: "default",
           path: {
-            cwd: tmp.path,
-            root: tmp.path,
+            cwd: Path.pretty(tmp.path),
+            root: Path.pretty(tmp.path),
           },
           cost: 0,
           tokens: {
@@ -115,8 +116,8 @@ describe("revert + compact workflow", () => {
           mode: "default",
           agent: "default",
           path: {
-            cwd: tmp.path,
-            root: tmp.path,
+            cwd: Path.pretty(tmp.path),
+            root: Path.pretty(tmp.path),
           },
           cost: 0,
           tokens: {
@@ -229,8 +230,8 @@ describe("revert + compact workflow", () => {
           mode: "default",
           agent: "default",
           path: {
-            cwd: tmp.path,
-            root: tmp.path,
+            cwd: Path.pretty(tmp.path),
+            root: Path.pretty(tmp.path),
           },
           cost: 0,
           tokens: {
diff --git a/packages/opencode/test/session/structured-output.test.ts b/packages/opencode/test/session/structured-output.test.ts
index f6131b149b57..aa7517c34a56 100644
--- a/packages/opencode/test/session/structured-output.test.ts
+++ b/packages/opencode/test/session/structured-output.test.ts
@@ -1,4 +1,5 @@
 import { describe, expect, test } from "bun:test"
+import { Path } from "../../src/path/path"
 import { MessageV2 } from "../../src/session/message-v2"
 import { SessionPrompt } from "../../src/session/prompt"
 import { SessionID, MessageID } from "../../src/session/schema"
@@ -133,7 +134,7 @@ describe("structured-output.AssistantMessage", () => {
     providerID: "anthropic",
     mode: "default",
     agent: "default",
-    path: { cwd: "/test", root: "/test" },
+    path: { cwd: Path.pretty("/test"), root: Path.pretty("/test") },
     cost: 0.001,
     tokens: { input: 100, output: 50, reasoning: 0, cache: { read: 0, write: 0 } },
     time: { created: Date.now() },
diff --git a/packages/opencode/test/snapshot/snapshot.test.ts b/packages/opencode/test/snapshot/snapshot.test.ts
index bf54feb4723d..d2971e9b827e 100644
--- a/packages/opencode/test/snapshot/snapshot.test.ts
+++ b/packages/opencode/test/snapshot/snapshot.test.ts
@@ -7,10 +7,9 @@ import { Instance } from "../../src/project/instance"
 import { Filesystem } from "../../src/util/filesystem"
 import { tmpdir } from "../fixture/fixture"
 
-// Git always outputs /-separated paths internally. Snapshot.patch() joins them
-// with path.join (which produces \ on Windows) then normalizes back to /.
-// This helper does the same for expected values so assertions match cross-platform.
-const fwd = (...parts: string[]) => path.join(...parts).replaceAll("\\", "/")
+// Snapshot.patch() now returns native pretty paths, so expected values should
+// match the host separator and casing rules.
+const fwd = (...parts: string[]) => path.join(...parts)
 
 afterEach(async () => {
   await Instance.disposeAll()
diff --git a/packages/opencode/test/storage/json-migration.test.ts b/packages/opencode/test/storage/json-migration.test.ts
index a714f1147345..649fb44afbc6 100644
--- a/packages/opencode/test/storage/json-migration.test.ts
+++ b/packages/opencode/test/storage/json-migration.test.ts
@@ -126,9 +126,9 @@ describe("JSON to SQLite migration", () => {
     const projects = db.select().from(ProjectTable).all()
     expect(projects.length).toBe(1)
     expect(projects[0].id).toBe(ProjectID.make("proj_test123abc"))
-    expect(projects[0].worktree).toBe("/test/path")
+    expect(String(projects[0].worktree)).toBe("/test/path")
     expect(projects[0].name).toBe("Test Project")
-    expect(projects[0].sandboxes).toEqual(["/test/sandbox"])
+    expect(projects[0].sandboxes.map(String)).toEqual(["/test/sandbox"])
   })
 
   test("uses filename for project id when JSON has different value", async () => {
diff --git a/packages/opencode/test/tool/apply_patch.test.ts b/packages/opencode/test/tool/apply_patch.test.ts
index 4e276517f104..b014a7793ab4 100644
--- a/packages/opencode/test/tool/apply_patch.test.ts
+++ b/packages/opencode/test/tool/apply_patch.test.ts
@@ -145,6 +145,7 @@ describe("tool.apply_patch freeform", () => {
 
         expect(calls.length).toBe(1)
         const permissionCall = calls[0]
+        expect(permissionCall.patterns).toEqual(["old/name.txt", "renamed/dir/name.txt"])
         expect(permissionCall.metadata.files).toHaveLength(1)
 
         const moveFile = permissionCall.metadata.files[0]
diff --git a/packages/opencode/test/tool/bash.test.ts b/packages/opencode/test/tool/bash.test.ts
index 4d680d494f35..cbf85ba1a10e 100644
--- a/packages/opencode/test/tool/bash.test.ts
+++ b/packages/opencode/test/tool/bash.test.ts
@@ -1,4 +1,5 @@
 import { describe, expect, test } from "bun:test"
+import fs from "fs/promises"
 import os from "os"
 import path from "path"
 import { BashTool } from "../../src/tool/bash"
@@ -8,6 +9,7 @@ import { tmpdir } from "../fixture/fixture"
 import type { Permission } from "../../src/permission"
 import { Truncate } from "../../src/tool/truncate"
 import { SessionID, MessageID } from "../../src/session/schema"
+import { resolveExternalDirectory } from "../../src/tool/external-directory"
 
 const ctx = {
   sessionID: SessionID.make("ses_test"),
@@ -22,6 +24,10 @@ const ctx = {
 
 const projectRoot = path.join(__dirname, "../..")
 
+async function link(target: string, alias: string) {
+  await fs.symlink(target, alias, process.platform === "win32" ? "junction" : "dir")
+}
+
 describe("tool.bash", () => {
   test("basic", async () => {
     await Instance.provide({
@@ -146,8 +152,46 @@ describe("tool.bash permissions", () => {
           testCtx,
         )
         const extDirReq = requests.find((r) => r.permission === "external_directory")
+        const expected = (await resolveExternalDirectory(os.tmpdir(), { kind: "directory" })).glob
+        expect(extDirReq).toBeDefined()
+        expect(extDirReq!.patterns).toContain(expected)
+      },
+    })
+  })
+
+  test("asks for external_directory permission when workdir alias resolves outside project", async () => {
+    await using outer = await tmpdir()
+    await using tmp = await tmpdir({
+      git: true,
+      init: async (dir) => {
+        await link(outer.path, path.join(dir, "link"))
+      },
+    })
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const bash = await BashTool.init()
+        const requests: Array<Omit<Permission.Request, "id" | "sessionID" | "tool">> = []
+        const testCtx = {
+          ...ctx,
+          ask: async (req: Omit<Permission.Request, "id" | "sessionID" | "tool">) => {
+            requests.push(req)
+          },
+        }
+        const alias = path.join(tmp.path, "link")
+        await bash.execute(
+          {
+            command: "echo hello",
+            workdir: alias,
+            description: "Echo hello",
+          },
+          testCtx,
+        )
+        const extDirReq = requests.find((r) => r.permission === "external_directory")
+        const expected = (await resolveExternalDirectory(alias, { kind: "directory" })).glob
         expect(extDirReq).toBeDefined()
-        expect(extDirReq!.patterns).toContain(path.join(os.tmpdir(), "*"))
+        expect(extDirReq!.patterns).toContain(expected)
+        expect(extDirReq!.always).toContain(expected)
       },
     })
   })
@@ -179,7 +223,7 @@ describe("tool.bash permissions", () => {
           testCtx,
         )
         const extDirReq = requests.find((r) => r.permission === "external_directory")
-        const expected = path.join(outerTmp.path, "*")
+        const expected = (await resolveExternalDirectory(filepath)).glob
         expect(extDirReq).toBeDefined()
         expect(extDirReq!.patterns).toContain(expected)
         expect(extDirReq!.always).toContain(expected)
diff --git a/packages/opencode/test/tool/edit.test.ts b/packages/opencode/test/tool/edit.test.ts
index f6b1ee5c926b..12349ba80ca6 100644
--- a/packages/opencode/test/tool/edit.test.ts
+++ b/packages/opencode/test/tool/edit.test.ts
@@ -5,7 +5,10 @@ import { EditTool } from "../../src/tool/edit"
 import { Instance } from "../../src/project/instance"
 import { tmpdir } from "../fixture/fixture"
 import { FileTime } from "../../src/file/time"
+import { Path } from "../../src/path/path"
 import { SessionID, MessageID } from "../../src/session/schema"
+import type { Permission } from "../../src/permission"
+import { win } from "../lib/windows-path"
 
 const ctx = {
   sessionID: SessionID.make("ses_test-edit-session"),
@@ -18,6 +21,7 @@ const ctx = {
   ask: async () => {},
 }
 
+const pretty = (file: string) => Path.pretty(file)
 afterEach(async () => {
   await Instance.disposeAll()
 })
@@ -120,7 +124,7 @@ describe("tool.edit", () => {
       await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          await FileTime.read(ctx.sessionID, filepath)
+          await FileTime.read(ctx.sessionID, pretty(filepath))
 
           const edit = await EditTool.init()
           const result = await edit.execute(
@@ -147,7 +151,7 @@ describe("tool.edit", () => {
       await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          await FileTime.read(ctx.sessionID, filepath)
+          await FileTime.read(ctx.sessionID, pretty(filepath))
 
           const edit = await EditTool.init()
           await expect(
@@ -195,7 +199,7 @@ describe("tool.edit", () => {
       await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          await FileTime.read(ctx.sessionID, filepath)
+          await FileTime.read(ctx.sessionID, pretty(filepath))
 
           const edit = await EditTool.init()
           await expect(
@@ -245,7 +249,7 @@ describe("tool.edit", () => {
         directory: tmp.path,
         fn: async () => {
           // Read first
-          await FileTime.read(ctx.sessionID, filepath)
+          await FileTime.read(ctx.sessionID, pretty(filepath))
 
           // Simulate external modification
           await fs.writeFile(filepath, "modified externally", "utf-8")
@@ -275,7 +279,7 @@ describe("tool.edit", () => {
       await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          await FileTime.read(ctx.sessionID, filepath)
+          await FileTime.read(ctx.sessionID, pretty(filepath))
 
           const edit = await EditTool.init()
           await edit.execute(
@@ -302,7 +306,7 @@ describe("tool.edit", () => {
       await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          await FileTime.read(ctx.sessionID, filepath)
+          await FileTime.read(ctx.sessionID, pretty(filepath))
 
           const { Bus } = await import("../../src/bus")
           const { File } = await import("../../src/file")
@@ -340,7 +344,7 @@ describe("tool.edit", () => {
       await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          await FileTime.read(ctx.sessionID, filepath)
+          await FileTime.read(ctx.sessionID, pretty(filepath))
 
           const edit = await EditTool.init()
           await edit.execute(
@@ -366,7 +370,7 @@ describe("tool.edit", () => {
       await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          await FileTime.read(ctx.sessionID, filepath)
+          await FileTime.read(ctx.sessionID, pretty(filepath))
 
           const edit = await EditTool.init()
           await edit.execute(
@@ -415,7 +419,7 @@ describe("tool.edit", () => {
       await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          await FileTime.read(ctx.sessionID, dirpath)
+          await FileTime.read(ctx.sessionID, pretty(dirpath))
 
           const edit = await EditTool.init()
           await expect(
@@ -440,7 +444,7 @@ describe("tool.edit", () => {
       await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          await FileTime.read(ctx.sessionID, filepath)
+          await FileTime.read(ctx.sessionID, pretty(filepath))
 
           const edit = await EditTool.init()
           const result = await edit.execute(
@@ -453,7 +457,7 @@ describe("tool.edit", () => {
           )
 
           expect(result.metadata.filediff).toBeDefined()
-          expect(result.metadata.filediff.file).toBe(filepath)
+          expect(String(result.metadata.filediff.file)).toBe(String(Path.repo(path.basename(filepath))))
           expect(result.metadata.filediff.additions).toBeGreaterThan(0)
         },
       })
@@ -511,7 +515,7 @@ describe("tool.edit", () => {
         fn: async () => {
           const edit = await EditTool.init()
           const filePath = path.join(tmp.path, "test.txt")
-          await FileTime.read(ctx.sessionID, filePath)
+          await FileTime.read(ctx.sessionID, pretty(filePath))
           await edit.execute(
             {
               filePath,
@@ -652,7 +656,7 @@ describe("tool.edit", () => {
       await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          await FileTime.read(ctx.sessionID, filepath)
+          await FileTime.read(ctx.sessionID, pretty(filepath))
 
           const edit = await EditTool.init()
 
@@ -667,7 +671,7 @@ describe("tool.edit", () => {
           )
 
           // Need to read again since FileTime tracks per-session
-          await FileTime.read(ctx.sessionID, filepath)
+          await FileTime.read(ctx.sessionID, pretty(filepath))
 
           const promise2 = edit.execute(
             {
@@ -685,4 +689,43 @@ describe("tool.edit", () => {
       })
     })
   })
+
+  test("canonicalizes external_directory permission across Windows aliases", async () => {
+    if (process.platform !== "win32") return
+    await using outerTmp = await tmpdir()
+    await using tmp = await tmpdir()
+
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const edit = await EditTool.init()
+        for (const item of win(path.join(outerTmp.path, "new.txt"))) {
+          const requests: Array<Omit<Permission.Request, "id" | "sessionID" | "tool">> = []
+          const stop = new Error("stop")
+          const testCtx = {
+            ...ctx,
+            ask: async (req: Omit<Permission.Request, "id" | "sessionID" | "tool">) => {
+              requests.push(req)
+              if (req.permission === "external_directory") throw stop
+            },
+          }
+
+          await expect(
+            edit.execute(
+              {
+                filePath: item.path,
+                oldString: "",
+                newString: "new content",
+              },
+              testCtx,
+            ),
+          ).rejects.toBe(stop)
+
+          const extDirReq = requests.find((r) => r.permission === "external_directory")
+          expect(extDirReq).toBeDefined()
+          expect(extDirReq!.patterns).toEqual([path.join(outerTmp.path, "*").replaceAll("\\", "/")])
+        }
+      },
+    })
+  })
 })
diff --git a/packages/opencode/test/tool/external-directory.test.ts b/packages/opencode/test/tool/external-directory.test.ts
index 0188cbada044..6809cafa57c8 100644
--- a/packages/opencode/test/tool/external-directory.test.ts
+++ b/packages/opencode/test/tool/external-directory.test.ts
@@ -1,10 +1,14 @@
 import { describe, expect, test } from "bun:test"
+import fs from "fs/promises"
 import path from "path"
+import { Path } from "../../src/path/path"
 import type { Tool } from "../../src/tool/tool"
 import { Instance } from "../../src/project/instance"
 import { assertExternalDirectory } from "../../src/tool/external-directory"
+import { tmpdir } from "../fixture/fixture"
 import type { Permission } from "../../src/permission"
 import { SessionID, MessageID } from "../../src/session/schema"
+import { win } from "../lib/windows-path"
 
 const baseCtx: Omit<Tool.Context, "ask"> = {
   sessionID: SessionID.make("ses_test"),
@@ -16,7 +20,15 @@ const baseCtx: Omit<Tool.Context, "ask"> = {
   metadata: () => {},
 }
 
+async function link(target: string, alias: string) {
+  await fs.symlink(target, alias, process.platform === "win32" ? "junction" : "dir")
+}
+
 describe("tool.assertExternalDirectory", () => {
+  test("normalizes Windows-style directory globs", () => {
+    expect(Path.externalGlob("C:\\Users\\Dev\\tmp\\", { platform: "win32" })).toBe("C:/Users/Dev/tmp/*")
+  })
+
   test("no-ops for empty target", async () => {
     const requests: Array<Omit<Permission.Request, "id" | "sessionID" | "tool">> = []
     const ctx: Tool.Context = {
@@ -66,7 +78,7 @@ describe("tool.assertExternalDirectory", () => {
 
     const directory = "/tmp/project"
     const target = "/tmp/outside/file.txt"
-    const expected = path.join(path.dirname(target), "*").replaceAll("\\", "/")
+    const expected = Path.externalGlob(path.resolve(path.dirname(target)))
 
     await Instance.provide({
       directory,
@@ -92,7 +104,7 @@ describe("tool.assertExternalDirectory", () => {
 
     const directory = "/tmp/project"
     const target = "/tmp/outside"
-    const expected = path.join(target, "*").replaceAll("\\", "/")
+    const expected = Path.externalGlob(path.resolve(target))
 
     await Instance.provide({
       directory,
@@ -107,7 +119,18 @@ describe("tool.assertExternalDirectory", () => {
     expect(req!.always).toEqual([expected])
   })
 
-  test("skips prompting when bypass=true", async () => {
+  test("asks for lexically internal paths that resolve outside via symlink", async () => {
+    await using outer = await tmpdir({
+      init: async (dir) => {
+        await Bun.write(path.join(dir, "secret.txt"), "secret")
+      },
+    })
+    await using tmp = await tmpdir({
+      init: async (dir) => {
+        await link(outer.path, path.join(dir, "link"))
+      },
+    })
+
     const requests: Array<Omit<Permission.Request, "id" | "sessionID" | "tool">> = []
     const ctx: Tool.Context = {
       ...baseCtx,
@@ -117,12 +140,98 @@ describe("tool.assertExternalDirectory", () => {
     }
 
     await Instance.provide({
-      directory: "/tmp/project",
+      directory: tmp.path,
       fn: async () => {
-        await assertExternalDirectory(ctx, "/tmp/outside/file.txt", { bypass: true })
+        await assertExternalDirectory(ctx, path.join(tmp.path, "link", "secret.txt"))
       },
     })
 
-    expect(requests.length).toBe(0)
+    const req = requests.find((r) => r.permission === "external_directory")
+    expect(req).toBeDefined()
+    expect(req!.patterns).toEqual([Path.externalGlob(outer.path)])
+  })
+
+  test("asks with the same canonical glob across Windows aliases", async () => {
+    if (process.platform !== "win32") return
+    await using outer = await tmpdir()
+    await using tmp = await tmpdir()
+
+    for (const item of win(path.join(outer.path, "secret.txt"))) {
+      const requests: Array<Omit<Permission.Request, "id" | "sessionID" | "tool">> = []
+      const ctx: Tool.Context = {
+        ...baseCtx,
+        ask: async (req) => {
+          requests.push(req)
+        },
+      }
+
+      await Instance.provide({
+        directory: tmp.path,
+        fn: async () => {
+          await assertExternalDirectory(ctx, item.path)
+        },
+      })
+
+      const req = requests.find((r) => r.permission === "external_directory")
+      expect(req).toBeDefined()
+      expect(req!.patterns).toEqual([Path.externalGlob(outer.path)])
+      expect(req!.always).toEqual([Path.externalGlob(outer.path)])
+    }
+  })
+
+  test("uses physical parent for missing file paths through symlink", async () => {
+    await using outer = await tmpdir()
+    await using tmp = await tmpdir({
+      init: async (dir) => {
+        await link(outer.path, path.join(dir, "link"))
+      },
+    })
+
+    const requests: Array<Omit<Permission.Request, "id" | "sessionID" | "tool">> = []
+    const ctx: Tool.Context = {
+      ...baseCtx,
+      ask: async (req) => {
+        requests.push(req)
+      },
+    }
+
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        await assertExternalDirectory(ctx, path.join(tmp.path, "link", "new.txt"))
+      },
+    })
+
+    const req = requests.find((r) => r.permission === "external_directory")
+    expect(req).toBeDefined()
+    expect(req!.patterns).toEqual([Path.externalGlob(outer.path)])
+  })
+
+  test("uses physical target for missing directories through symlink", async () => {
+    await using outer = await tmpdir()
+    await using tmp = await tmpdir({
+      init: async (dir) => {
+        await link(outer.path, path.join(dir, "link"))
+      },
+    })
+
+    const requests: Array<Omit<Permission.Request, "id" | "sessionID" | "tool">> = []
+    const ctx: Tool.Context = {
+      ...baseCtx,
+      ask: async (req) => {
+        requests.push(req)
+      },
+    }
+
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        await assertExternalDirectory(ctx, path.join(tmp.path, "link", "newdir"), { kind: "directory" })
+      },
+    })
+
+    const req = requests.find((r) => r.permission === "external_directory")
+    expect(req).toBeDefined()
+    expect(req!.patterns).toEqual([Path.externalGlob(path.join(outer.path, "newdir"))])
   })
 })
diff --git a/packages/opencode/test/tool/glob.test.ts b/packages/opencode/test/tool/glob.test.ts
new file mode 100644
index 000000000000..0d43fa3252d0
--- /dev/null
+++ b/packages/opencode/test/tool/glob.test.ts
@@ -0,0 +1,48 @@
+import { describe, expect, test } from "bun:test"
+import path from "path"
+import { GlobTool } from "../../src/tool/glob"
+import { Instance } from "../../src/project/instance"
+import { SessionID, MessageID } from "../../src/session/schema"
+import { tmpdir } from "../fixture/fixture"
+import { win } from "../lib/windows-path"
+
+const ctx = {
+  sessionID: SessionID.make("ses_test"),
+  messageID: MessageID.make(""),
+  callID: "",
+  agent: "build",
+  abort: AbortSignal.any([]),
+  messages: [],
+  metadata: () => {},
+  ask: async () => {},
+}
+
+describe("tool.glob", () => {
+  test("accepts Windows alias directories and returns canonical matches", async () => {
+    if (process.platform !== "win32") return
+    await using tmp = await tmpdir({
+      init: async (dir) => {
+        await Bun.write(path.join(dir, "src", "tool.ts"), "export const ok = true\n")
+      },
+    })
+
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const glob = await GlobTool.init()
+        for (const item of win(tmp.path)) {
+          const result = await glob.execute(
+            {
+              pattern: "**/*.ts",
+              path: item.path,
+            },
+            ctx,
+          )
+
+          expect(result.metadata.count).toBe(1)
+          expect(result.output).toContain(path.join(tmp.path, "src", "tool.ts"))
+        }
+      },
+    })
+  })
+})
diff --git a/packages/opencode/test/tool/grep.test.ts b/packages/opencode/test/tool/grep.test.ts
index e03b1752ec03..ccbc3bac70e9 100644
--- a/packages/opencode/test/tool/grep.test.ts
+++ b/packages/opencode/test/tool/grep.test.ts
@@ -4,6 +4,7 @@ import { GrepTool } from "../../src/tool/grep"
 import { Instance } from "../../src/project/instance"
 import { tmpdir } from "../fixture/fixture"
 import { SessionID, MessageID } from "../../src/session/schema"
+import { win } from "../lib/windows-path"
 
 const ctx = {
   sessionID: SessionID.make("ses_test"),
@@ -84,6 +85,34 @@ describe("tool.grep", () => {
       },
     })
   })
+
+  test("accepts Windows alias directories and reports canonical file paths", async () => {
+    if (process.platform !== "win32") return
+    await using tmp = await tmpdir({
+      init: async (dir) => {
+        await Bun.write(path.join(dir, "nested", "hit.txt"), "hello alias")
+      },
+    })
+
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const grep = await GrepTool.init()
+        for (const item of win(tmp.path)) {
+          const result = await grep.execute(
+            {
+              pattern: "hello",
+              path: item.path,
+            },
+            ctx,
+          )
+
+          expect(result.metadata.matches).toBe(1)
+          expect(result.output).toContain(path.join(tmp.path, "nested", "hit.txt"))
+        }
+      },
+    })
+  })
 })
 
 describe("CRLF regex handling", () => {
diff --git a/packages/opencode/test/tool/ls.test.ts b/packages/opencode/test/tool/ls.test.ts
new file mode 100644
index 000000000000..4a3d45b35c42
--- /dev/null
+++ b/packages/opencode/test/tool/ls.test.ts
@@ -0,0 +1,44 @@
+import { describe, expect, test } from "bun:test"
+import fs from "fs/promises"
+import path from "path"
+import { ListTool } from "../../src/tool/ls"
+import { Instance } from "../../src/project/instance"
+import { MessageID, SessionID } from "../../src/session/schema"
+import { tmpdir } from "../fixture/fixture"
+
+const ctx = {
+  sessionID: SessionID.make("ses_test"),
+  messageID: MessageID.make(""),
+  callID: "",
+  agent: "build",
+  abort: AbortSignal.any([]),
+  messages: [],
+  metadata: () => {},
+  ask: async () => {},
+}
+
+describe("tool.ls", () => {
+  test("renders repo-key trees under a native root path", async () => {
+    await using tmp = await tmpdir({
+      init: async (dir) => {
+        await fs.mkdir(path.join(dir, "src", "nested"), { recursive: true })
+        await fs.writeFile(path.join(dir, "src", "nested", "file.ts"), "export {}\n")
+        await fs.writeFile(path.join(dir, "src", "root.ts"), "export {}\n")
+      },
+    })
+
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const tool = await ListTool.init()
+        const result = await tool.execute({ path: tmp.path }, ctx)
+
+        expect(result.output.startsWith(`${tmp.path}${path.sep}\n`)).toBe(true)
+        expect(result.output).toContain("  src/\n")
+        expect(result.output).toContain("    nested/\n")
+        expect(result.output).toContain("      file.ts\n")
+        expect(result.output).toContain("    root.ts\n")
+      },
+    })
+  })
+})
diff --git a/packages/opencode/test/tool/lsp.test.ts b/packages/opencode/test/tool/lsp.test.ts
new file mode 100644
index 000000000000..5455415afcbf
--- /dev/null
+++ b/packages/opencode/test/tool/lsp.test.ts
@@ -0,0 +1,49 @@
+import { describe, expect, test } from "bun:test"
+import path from "path"
+import { LspTool } from "../../src/tool/lsp"
+import { Instance } from "../../src/project/instance"
+import { SessionID, MessageID } from "../../src/session/schema"
+import { tmpdir } from "../fixture/fixture"
+import { win } from "../lib/windows-path"
+
+const ctx = {
+  sessionID: SessionID.make("ses_test"),
+  messageID: MessageID.make(""),
+  callID: "",
+  agent: "build",
+  abort: AbortSignal.any([]),
+  messages: [],
+  metadata: () => {},
+  ask: async () => {},
+}
+
+describe("tool.lsp", () => {
+  test("accepts Windows alias file paths before LSP availability checks", async () => {
+    if (process.platform !== "win32") return
+    await using tmp = await tmpdir({
+      init: async (dir) => {
+        await Bun.write(path.join(dir, "note.txt"), "hello\n")
+      },
+    })
+
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const lsp = await LspTool.init()
+        for (const item of win(path.join(tmp.path, "note.txt"))) {
+          await expect(
+            lsp.execute(
+              {
+                operation: "hover",
+                filePath: item.path,
+                line: 1,
+                character: 1,
+              },
+              ctx,
+            ),
+          ).rejects.toThrow("No LSP server available")
+        }
+      },
+    })
+  })
+})
diff --git a/packages/opencode/test/tool/read.test.ts b/packages/opencode/test/tool/read.test.ts
index 06a7f9a70693..ce4ed5c55415 100644
--- a/packages/opencode/test/tool/read.test.ts
+++ b/packages/opencode/test/tool/read.test.ts
@@ -1,4 +1,5 @@
 import { afterEach, describe, expect, test } from "bun:test"
+import fs from "fs/promises"
 import path from "path"
 import { ReadTool } from "../../src/tool/read"
 import { Instance } from "../../src/project/instance"
@@ -7,6 +8,7 @@ import { tmpdir } from "../fixture/fixture"
 import { Permission } from "../../src/permission"
 import { Agent } from "../../src/agent/agent"
 import { SessionID, MessageID } from "../../src/session/schema"
+import { win } from "../lib/windows-path"
 
 const FIXTURES_DIR = path.join(import.meta.dir, "fixtures")
 
@@ -25,6 +27,10 @@ const ctx = {
   ask: async () => {},
 }
 
+async function link(target: string, alias: string) {
+  await fs.symlink(target, alias, process.platform === "win32" ? "junction" : "dir")
+}
+
 describe("tool.read external_directory permission", () => {
   test("allows reading absolute path inside project directory", async () => {
     await using tmp = await tmpdir({
@@ -155,6 +161,68 @@ describe("tool.read external_directory permission", () => {
       },
     })
   })
+
+  test("asks for external_directory permission when reading through symlink escape", async () => {
+    await using outerTmp = await tmpdir({
+      init: async (dir) => {
+        await Bun.write(path.join(dir, "secret.txt"), "secret data")
+      },
+    })
+    await using tmp = await tmpdir({
+      git: true,
+      init: async (dir) => {
+        await link(outerTmp.path, path.join(dir, "link"))
+      },
+    })
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const read = await ReadTool.init()
+        const requests: Array<Omit<Permission.Request, "id" | "sessionID" | "tool">> = []
+        const testCtx = {
+          ...ctx,
+          ask: async (req: Omit<Permission.Request, "id" | "sessionID" | "tool">) => {
+            requests.push(req)
+          },
+        }
+        const result = await read.execute({ filePath: path.join(tmp.path, "link", "secret.txt") }, testCtx)
+        const extDirReq = requests.find((r) => r.permission === "external_directory")
+        expect(result.output).toContain("secret data")
+        expect(extDirReq).toBeDefined()
+        expect(extDirReq!.patterns).toContain(path.join(outerTmp.path, "*").replaceAll("\\", "/"))
+      },
+    })
+  })
+
+  test("canonicalizes external_directory permission across Windows aliases", async () => {
+    if (process.platform !== "win32") return
+    await using outerTmp = await tmpdir()
+    await using tmp = await tmpdir({ git: true })
+    const expected = path.join(outerTmp.path, "*").replaceAll("\\", "/")
+
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const read = await ReadTool.init()
+        for (const item of win(path.join(outerTmp.path, "secret.txt"))) {
+          const requests: Array<Omit<Permission.Request, "id" | "sessionID" | "tool">> = []
+          const stop = new Error("stop")
+          const testCtx = {
+            ...ctx,
+            ask: async (req: Omit<Permission.Request, "id" | "sessionID" | "tool">) => {
+              requests.push(req)
+              if (req.permission === "external_directory") throw stop
+            },
+          }
+
+          await expect(read.execute({ filePath: item.path }, testCtx)).rejects.toBe(stop)
+          const extDirReq = requests.find((r) => r.permission === "external_directory")
+          expect(extDirReq).toBeDefined()
+          expect(extDirReq!.patterns).toEqual([expected])
+        }
+      },
+    })
+  })
 })
 
 describe("tool.read env file permissions", () => {
diff --git a/packages/opencode/test/tool/task.test.ts b/packages/opencode/test/tool/task.test.ts
index aae48a30ab3f..8b88031801ec 100644
--- a/packages/opencode/test/tool/task.test.ts
+++ b/packages/opencode/test/tool/task.test.ts
@@ -1,4 +1,5 @@
 import { afterEach, describe, expect, test } from "bun:test"
+import z from "zod"
 import { Agent } from "../../src/agent/agent"
 import { Instance } from "../../src/project/instance"
 import { TaskTool } from "../../src/tool/task"
@@ -9,6 +10,27 @@ afterEach(async () => {
 })
 
 describe("tool.task", () => {
+  test("exports task_id as a JSON-schema-safe string", async () => {
+    await using tmp = await tmpdir({ git: true })
+
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const tool = await TaskTool.init()
+        const schema = z.toJSONSchema(tool.parameters)
+
+        expect(schema).toMatchObject({
+          type: "object",
+          properties: {
+            task_id: {
+              type: "string",
+            },
+          },
+        })
+      },
+    })
+  })
+
   test("description sorts subagents by name and is stable across calls", async () => {
     await using tmp = await tmpdir({
       config: {
diff --git a/packages/opencode/test/tool/write.test.ts b/packages/opencode/test/tool/write.test.ts
index 97939c10519e..5f94e1475ede 100644
--- a/packages/opencode/test/tool/write.test.ts
+++ b/packages/opencode/test/tool/write.test.ts
@@ -4,7 +4,10 @@ import fs from "fs/promises"
 import { WriteTool } from "../../src/tool/write"
 import { Instance } from "../../src/project/instance"
 import { tmpdir } from "../fixture/fixture"
+import type { Permission } from "../../src/permission"
 import { SessionID, MessageID } from "../../src/session/schema"
+import { Path } from "../../src/path/path"
+import { win } from "../lib/windows-path"
 
 const ctx = {
   sessionID: SessionID.make("ses_test-write-session"),
@@ -17,6 +20,11 @@ const ctx = {
   ask: async () => {},
 }
 
+const pretty = (file: string) => Path.pretty(file)
+
+async function link(target: string, alias: string) {
+  await fs.symlink(target, alias, process.platform === "win32" ? "junction" : "dir")
+}
 afterEach(async () => {
   await Instance.disposeAll()
 })
@@ -90,6 +98,80 @@ describe("tool.write", () => {
         },
       })
     })
+
+    test("asks for external_directory permission when writing through symlink escape", async () => {
+      await using outerTmp = await tmpdir()
+      await using tmp = await tmpdir({
+        init: async (dir) => {
+          await link(outerTmp.path, path.join(dir, "link"))
+        },
+      })
+
+      await Instance.provide({
+        directory: tmp.path,
+        fn: async () => {
+          const write = await WriteTool.init()
+          const requests: Array<Omit<Permission.Request, "id" | "sessionID" | "tool">> = []
+          const testCtx = {
+            ...ctx,
+            ask: async (req: Omit<Permission.Request, "id" | "sessionID" | "tool">) => {
+              requests.push(req)
+            },
+          }
+
+          await write.execute(
+            {
+              filePath: path.join(tmp.path, "link", "new.txt"),
+              content: "escaped",
+            },
+            testCtx,
+          )
+
+          const extDirReq = requests.find((r) => r.permission === "external_directory")
+          expect(extDirReq).toBeDefined()
+          expect(extDirReq!.patterns).toContain(path.join(outerTmp.path, "*").replaceAll("\\", "/"))
+          expect(await fs.readFile(path.join(outerTmp.path, "new.txt"), "utf-8")).toBe("escaped")
+        },
+      })
+    })
+
+    test("canonicalizes external_directory permission across Windows aliases", async () => {
+      if (process.platform !== "win32") return
+      await using outerTmp = await tmpdir()
+      await using tmp = await tmpdir()
+
+      await Instance.provide({
+        directory: tmp.path,
+        fn: async () => {
+          const write = await WriteTool.init()
+          for (const item of win(path.join(outerTmp.path, "new.txt"))) {
+            const requests: Array<Omit<Permission.Request, "id" | "sessionID" | "tool">> = []
+            const stop = new Error("stop")
+            const testCtx = {
+              ...ctx,
+              ask: async (req: Omit<Permission.Request, "id" | "sessionID" | "tool">) => {
+                requests.push(req)
+                if (req.permission === "external_directory") throw stop
+              },
+            }
+
+            await expect(
+              write.execute(
+                {
+                  filePath: item.path,
+                  content: "escaped",
+                },
+                testCtx,
+              ),
+            ).rejects.toBe(stop)
+
+            const extDirReq = requests.find((r) => r.permission === "external_directory")
+            expect(extDirReq).toBeDefined()
+            expect(extDirReq!.patterns).toEqual([path.join(outerTmp.path, "*").replaceAll("\\", "/")])
+          }
+        },
+      })
+    })
   })
 
   describe("existing file overwrite", () => {
@@ -103,7 +185,7 @@ describe("tool.write", () => {
         directory: tmp.path,
         fn: async () => {
           const { FileTime } = await import("../../src/file/time")
-          await FileTime.read(ctx.sessionID, filepath)
+          await FileTime.read(ctx.sessionID, pretty(filepath))
 
           const write = await WriteTool.init()
           const result = await write.execute(
@@ -132,7 +214,7 @@ describe("tool.write", () => {
         directory: tmp.path,
         fn: async () => {
           const { FileTime } = await import("../../src/file/time")
-          await FileTime.read(ctx.sessionID, filepath)
+          await FileTime.read(ctx.sessionID, pretty(filepath))
 
           const write = await WriteTool.init()
           const result = await write.execute(
@@ -310,7 +392,7 @@ describe("tool.write", () => {
         directory: tmp.path,
         fn: async () => {
           const { FileTime } = await import("../../src/file/time")
-          await FileTime.read(ctx.sessionID, readonlyPath)
+          await FileTime.read(ctx.sessionID, pretty(readonlyPath))
 
           const write = await WriteTool.init()
           await expect(
diff --git a/packages/opencode/test/util/filesystem.test.ts b/packages/opencode/test/util/filesystem.test.ts
index aea0b1db87f5..f11611becec6 100644
--- a/packages/opencode/test/util/filesystem.test.ts
+++ b/packages/opencode/test/util/filesystem.test.ts
@@ -1,6 +1,7 @@
 import { describe, test, expect } from "bun:test"
 import path from "path"
 import fs from "fs/promises"
+import { Path } from "../../src/path/path"
 import { Filesystem } from "../../src/util/filesystem"
 import { tmpdir } from "../fixture/fixture"
 
@@ -286,37 +287,36 @@ describe("filesystem", () => {
     })
   })
 
-  describe("windowsPath()", () => {
-    test("converts Git Bash paths", () => {
-      if (process.platform === "win32") {
-        expect(Filesystem.windowsPath("/c/Users/test")).toBe("C:/Users/test")
-        expect(Filesystem.windowsPath("/d/dev/project")).toBe("D:/dev/project")
-      } else {
-        expect(Filesystem.windowsPath("/c/Users/test")).toBe("/c/Users/test")
-      }
+  describe("Path.contains()", () => {
+    test("rejects absolute-relative path mixes", () => {
+      const abs = process.platform === "win32" ? "C:\\project" : "/project"
+      const rel = process.platform === "win32" ? "project\\src\\file.ts" : "project/src/file.ts"
+
+      expect(Path.contains(abs, rel)).toBe(false)
+      expect(Path.contains(rel, path.join(abs, "src", "file.ts"))).toBe(false)
     })
 
-    test("converts Cygwin paths", () => {
-      if (process.platform === "win32") {
-        expect(Filesystem.windowsPath("/cygdrive/c/Users/test")).toBe("C:/Users/test")
-        expect(Filesystem.windowsPath("/cygdrive/x/dev/project")).toBe("X:/dev/project")
-      } else {
-        expect(Filesystem.windowsPath("/cygdrive/c/Users/test")).toBe("/cygdrive/c/Users/test")
-      }
+    test("rejects different roots", () => {
+      if (process.platform !== "win32") return
+
+      expect(Path.contains("C:\\project", "D:\\project\\file.ts")).toBe(false)
+      expect(Path.contains("C:\\project", "\\\\server\\share\\file.ts")).toBe(false)
     })
+  })
 
-    test("converts WSL paths", () => {
-      if (process.platform === "win32") {
-        expect(Filesystem.windowsPath("/mnt/c/Users/test")).toBe("C:/Users/test")
-        expect(Filesystem.windowsPath("/mnt/z/dev/project")).toBe("Z:/dev/project")
-      } else {
-        expect(Filesystem.windowsPath("/mnt/c/Users/test")).toBe("/mnt/c/Users/test")
-      }
+  describe("Path.overlaps()", () => {
+    test("stays false for absolute-relative path mixes", () => {
+      const abs = process.platform === "win32" ? "C:\\project" : "/project"
+      const rel = process.platform === "win32" ? "project\\src" : "project/src"
+
+      expect(Path.overlaps(abs, rel)).toBe(false)
     })
 
-    test("ignores normal Windows paths", () => {
-      expect(Filesystem.windowsPath("C:/Users/test")).toBe("C:/Users/test")
-      expect(Filesystem.windowsPath("D:\\dev\\project")).toBe("D:\\dev\\project")
+    test("stays false for different roots", () => {
+      if (process.platform !== "win32") return
+
+      expect(Path.overlaps("C:\\project", "D:\\project")).toBe(false)
+      expect(Path.overlaps("C:\\project", "\\\\server\\share\\project")).toBe(false)
     })
   })
 
@@ -441,19 +441,19 @@ describe("filesystem", () => {
     })
   })
 
-  describe("resolve()", () => {
+  describe("Path.truecaseSync()", () => {
     test("resolves slash-prefixed drive paths on Windows", async () => {
       if (process.platform !== "win32") return
       await using tmp = await tmpdir()
       const forward = tmp.path.replaceAll("\\", "/")
-      expect(Filesystem.resolve(`/${forward}`)).toBe(Filesystem.normalizePath(tmp.path))
+      expect(Path.truecaseSync(`/${forward}`)).toBe(Path.truecaseSync(tmp.path))
     })
 
     test("resolves slash-prefixed drive roots on Windows", async () => {
       if (process.platform !== "win32") return
       await using tmp = await tmpdir()
       const drive = tmp.path[0].toUpperCase()
-      expect(Filesystem.resolve(`/${drive}:`)).toBe(Filesystem.resolve(`${drive}:/`))
+      expect(Path.truecaseSync(`/${drive}:`)).toBe(Path.truecaseSync(`${drive}:/`))
     })
 
     test("resolves Git Bash and MSYS2 paths on Windows", async () => {
@@ -462,7 +462,7 @@ describe("filesystem", () => {
       await using tmp = await tmpdir()
       const drive = tmp.path[0].toLowerCase()
       const rest = tmp.path.slice(2).replaceAll("\\", "/")
-      expect(Filesystem.resolve(`/${drive}${rest}`)).toBe(Filesystem.normalizePath(tmp.path))
+      expect(Path.truecaseSync(`/${drive}${rest}`)).toBe(Path.truecaseSync(tmp.path))
     })
 
     test("resolves Git Bash and MSYS2 drive roots on Windows", async () => {
@@ -470,7 +470,7 @@ describe("filesystem", () => {
       if (process.platform !== "win32") return
       await using tmp = await tmpdir()
       const drive = tmp.path[0].toLowerCase()
-      expect(Filesystem.resolve(`/${drive}`)).toBe(Filesystem.resolve(`${drive.toUpperCase()}:/`))
+      expect(Path.truecaseSync(`/${drive}`)).toBe(Path.truecaseSync(`${drive.toUpperCase()}:/`))
     })
 
     test("resolves Cygwin paths on Windows", async () => {
@@ -478,14 +478,14 @@ describe("filesystem", () => {
       await using tmp = await tmpdir()
       const drive = tmp.path[0].toLowerCase()
       const rest = tmp.path.slice(2).replaceAll("\\", "/")
-      expect(Filesystem.resolve(`/cygdrive/${drive}${rest}`)).toBe(Filesystem.normalizePath(tmp.path))
+      expect(Path.truecaseSync(`/cygdrive/${drive}${rest}`)).toBe(Path.truecaseSync(tmp.path))
     })
 
     test("resolves Cygwin drive roots on Windows", async () => {
       if (process.platform !== "win32") return
       await using tmp = await tmpdir()
       const drive = tmp.path[0].toLowerCase()
-      expect(Filesystem.resolve(`/cygdrive/${drive}`)).toBe(Filesystem.resolve(`${drive.toUpperCase()}:/`))
+      expect(Path.truecaseSync(`/cygdrive/${drive}`)).toBe(Path.truecaseSync(`${drive.toUpperCase()}:/`))
     })
 
     test("resolves WSL mount paths on Windows", async () => {
@@ -493,66 +493,50 @@ describe("filesystem", () => {
       await using tmp = await tmpdir()
       const drive = tmp.path[0].toLowerCase()
       const rest = tmp.path.slice(2).replaceAll("\\", "/")
-      expect(Filesystem.resolve(`/mnt/${drive}${rest}`)).toBe(Filesystem.normalizePath(tmp.path))
+      expect(Path.truecaseSync(`/mnt/${drive}${rest}`)).toBe(Path.truecaseSync(tmp.path))
     })
 
     test("resolves WSL mount roots on Windows", async () => {
       if (process.platform !== "win32") return
       await using tmp = await tmpdir()
       const drive = tmp.path[0].toLowerCase()
-      expect(Filesystem.resolve(`/mnt/${drive}`)).toBe(Filesystem.resolve(`${drive.toUpperCase()}:/`))
+      expect(Path.truecaseSync(`/mnt/${drive}`)).toBe(Path.truecaseSync(`${drive.toUpperCase()}:/`))
     })
 
-    test("resolves symlinked directory to canonical path", async () => {
+    test("preserves symlinked directory roots", async () => {
       await using tmp = await tmpdir()
       const target = path.join(tmp.path, "real")
       await fs.mkdir(target)
-      const link = path.join(tmp.path, "link")
+      const link = path.join(tmp.path, "alias")
       await fs.symlink(target, link)
-      expect(Filesystem.resolve(link)).toBe(Filesystem.resolve(target))
+      expect(String(Path.truecaseSync(link))).toBe(path.resolve(link))
+      expect(String(Path.truecaseSync(link))).not.toBe(String(Path.truecaseSync(target)))
+    })
+
+    test("preserves symlink roots for nested paths", async () => {
+      await using tmp = await tmpdir()
+      const target = path.join(tmp.path, "real")
+      const child = path.join(target, "child")
+      await fs.mkdir(child, { recursive: true })
+      const link = path.join(tmp.path, "alias")
+      await fs.symlink(target, link)
+      expect(String(Path.truecaseSync(path.join(link, "child")))).toBe(path.resolve(link, "child"))
     })
 
     test("returns unresolved path when target does not exist", async () => {
       await using tmp = await tmpdir()
       const missing = path.join(tmp.path, "does-not-exist-" + Date.now())
-      const result = Filesystem.resolve(missing)
-      expect(result).toBe(Filesystem.normalizePath(path.resolve(missing)))
+      const result = Path.truecaseSync(missing)
+      expect(result).toBe(Path.truecaseSync(path.resolve(missing)))
     })
 
-    test("throws ELOOP on symlink cycle", async () => {
+    test("keeps cyclic symlink paths as typed", async () => {
       await using tmp = await tmpdir()
       const a = path.join(tmp.path, "a")
       const b = path.join(tmp.path, "b")
       await fs.symlink(b, a)
       await fs.symlink(a, b)
-      expect(() => Filesystem.resolve(a)).toThrow()
-    })
-
-    // Windows: chmod(0o000) is a no-op, so EACCES cannot be triggered
-    test("throws EACCES on permission-denied symlink target", async () => {
-      if (process.platform === "win32") return
-      if (process.getuid?.() === 0) return // skip when running as root
-      await using tmp = await tmpdir()
-      const dir = path.join(tmp.path, "restricted")
-      await fs.mkdir(dir)
-      const link = path.join(tmp.path, "link")
-      await fs.symlink(dir, link)
-      await fs.chmod(dir, 0o000)
-      try {
-        expect(() => Filesystem.resolve(path.join(link, "child"))).toThrow()
-      } finally {
-        await fs.chmod(dir, 0o755)
-      }
-    })
-
-    // Windows: traversing through a file throws ENOENT (not ENOTDIR),
-    // which resolve() catches as a fallback instead of rethrowing
-    test("rethrows non-ENOENT errors", async () => {
-      if (process.platform === "win32") return
-      await using tmp = await tmpdir()
-      const file = path.join(tmp.path, "not-a-directory")
-      await fs.writeFile(file, "x")
-      expect(() => Filesystem.resolve(path.join(file, "child"))).toThrow()
+      expect(String(Path.truecaseSync(path.join(a, "child")))).toBe(path.resolve(a, "child"))
     })
   })
 })
diff --git a/packages/sdk/js/src/v2/gen/types.gen.ts b/packages/sdk/js/src/v2/gen/types.gen.ts
index 86a0c7e42564..1b0599e7bfc2 100644
--- a/packages/sdk/js/src/v2/gen/types.gen.ts
+++ b/packages/sdk/js/src/v2/gen/types.gen.ts
@@ -18,6 +18,13 @@ export type EventInstallationUpdateAvailable = {
   }
 }
 
+export type EventFileEdited = {
+  type: "file.edited"
+  properties: {
+    file: string
+  }
+}
+
 export type Project = {
   id: string
   worktree: string
@@ -73,6 +80,7 @@ export type EventLspClientDiagnostics = {
   properties: {
     serverID: string
     path: string
+    pathKey: string
   }
 }
 
@@ -83,13 +91,6 @@ export type EventLspUpdated = {
   }
 }
 
-export type EventFileEdited = {
-  type: "file.edited"
-  properties: {
-    file: string
-  }
-}
-
 export type OutputFormatText = {
   type: "text"
 }
@@ -1881,6 +1882,7 @@ export type McpStatus =
   | McpStatusNeedsClientRegistration
 
 export type Path = {
+  os: "macos" | "windows" | "linux"
   home: string
   state: string
   config: string
diff --git a/packages/ui/src/components/file-media.tsx b/packages/ui/src/components/file-media.tsx
index 2fd54588a3c0..463167c4e1a2 100644
--- a/packages/ui/src/components/file-media.tsx
+++ b/packages/ui/src/components/file-media.tsx
@@ -1,4 +1,5 @@
 import type { FileContent } from "@opencode-ai/sdk/v2"
+import { getFilename } from "@opencode-ai/util/path"
 import { createEffect, createMemo, createResource, Match, on, Show, Switch, type JSX } from "solid-js"
 import { useI18n } from "../context/i18n"
 import {
@@ -248,7 +249,7 @@ export function FileMedia(props: { media?: FileMediaOptions; fallback: () => JSX
       <Match when={isBinary()}>
         <div class="flex min-h-56 flex-col items-center justify-center gap-2 px-6 py-10 text-center">
           <div class="text-14-semibold text-text-strong">
-            {cfg()?.path?.split("/").pop() ?? i18n.t("ui.fileMedia.binary.title")}
+            {getFilename(cfg()?.path) || i18n.t("ui.fileMedia.binary.title")}
           </div>
           <div class="text-14-regular text-text-weak">
             {(() => {
diff --git a/packages/ui/src/components/message-part.tsx b/packages/ui/src/components/message-part.tsx
index e8c9dcf9505b..61d31f82ea3b 100644
--- a/packages/ui/src/components/message-part.tsx
+++ b/packages/ui/src/components/message-part.tsx
@@ -45,7 +45,7 @@ import { Checkbox } from "./checkbox"
 import { DiffChanges } from "./diff-changes"
 import { Markdown } from "./markdown"
 import { ImagePreview } from "./image-preview"
-import { getDirectory as _getDirectory, getFilename } from "@opencode-ai/util/path"
+import { getDirectory as _getDirectory, getFilename, getRelativeDisplayPath } from "@opencode-ai/util/path"
 import { checksum } from "@opencode-ai/util/encode"
 import { Tooltip } from "./tooltip"
 import { IconButton } from "./icon-button"
@@ -192,22 +192,9 @@ function createThrottledValue(getValue: () => string) {
   return value
 }
 
-function relativizeProjectPath(path: string, directory?: string) {
-  if (!path) return ""
-  if (!directory) return path
-  if (directory === "/") return path
-  if (directory === "\\") return path
-  if (path === directory) return ""
-
-  const separator = directory.includes("\\") ? "\\" : "/"
-  const prefix = directory.endsWith(separator) ? directory : directory + separator
-  if (!path.startsWith(prefix)) return path
-  return path.slice(directory.length)
-}
-
 function getDirectory(path: string | undefined) {
   const data = useData()
-  return relativizeProjectPath(_getDirectory(path), data.directory)
+  return getRelativeDisplayPath(_getDirectory(path), data.directory)
 }
 
 import type { IconProps } from "./icon"
@@ -1172,6 +1159,7 @@ export const ToolRegistry = {
 
 function ToolFileAccordion(props: { path: string; actions?: JSX.Element; children: JSX.Element }) {
   const value = createMemo(() => props.path || "tool-file")
+  const dir = createMemo(() => getDirectory(props.path))
 
   return (
     <Accordion
@@ -1187,8 +1175,8 @@ function ToolFileAccordion(props: { path: string; actions?: JSX.Element; childre
               <div data-slot="apply-patch-file-info">
                 <FileIcon node={{ path: props.path, type: "file" }} />
                 <div data-slot="apply-patch-file-name-container">
-                  <Show when={props.path.includes("/")}>
-                    <span data-slot="apply-patch-directory">{`\u202A${getDirectory(props.path)}\u202C`}</span>
+                  <Show when={dir()}>
+                    <span data-slot="apply-patch-directory">{`\u202A${dir()}\u202C`}</span>
                   </Show>
                   <span data-slot="apply-patch-filename">{getFilename(props.path)}</span>
                 </div>
@@ -1457,7 +1445,7 @@ ToolRegistry.register({
             <div data-component="tool-loaded-file">
               <Icon name="enter" size="small" />
               <span>
-                {i18n.t("ui.tool.loaded")} {relativizeProjectPath(filepath, data.directory)}
+                {i18n.t("ui.tool.loaded")} {getRelativeDisplayPath(filepath, data.directory)}
               </span>
             </div>
           )}
@@ -1783,7 +1771,7 @@ ToolRegistry.register({
                     <span data-slot="message-part-title-filename">{filename()}</span>
                   </Show>
                 </div>
-                <Show when={!pending() && props.input.filePath?.includes("/")}>
+                <Show when={!pending() && getDirectory(props.input.filePath)}>
                   <div data-slot="message-part-path">
                     <span data-slot="message-part-directory">{getDirectory(props.input.filePath!)}</span>
                   </div>
@@ -1855,7 +1843,7 @@ ToolRegistry.register({
                     <span data-slot="message-part-title-filename">{filename()}</span>
                   </Show>
                 </div>
-                <Show when={!pending() && props.input.filePath?.includes("/")}>
+                <Show when={!pending() && getDirectory(props.input.filePath)}>
                   <div data-slot="message-part-path">
                     <span data-slot="message-part-directory">{getDirectory(props.input.filePath!)}</span>
                   </div>
@@ -1976,7 +1964,7 @@ ToolRegistry.register({
                                 <div data-slot="apply-patch-file-info">
                                   <FileIcon node={{ path: file.relativePath, type: "file" }} />
                                   <div data-slot="apply-patch-file-name-container">
-                                    <Show when={file.relativePath.includes("/")}>
+                                    <Show when={getDirectory(file.relativePath)}>
                                       <span data-slot="apply-patch-directory">{`\u202A${getDirectory(file.relativePath)}\u202C`}</span>
                                     </Show>
                                     <span data-slot="apply-patch-filename">{getFilename(file.relativePath)}</span>
@@ -2046,7 +2034,7 @@ ToolRegistry.register({
                       <span data-slot="message-part-title-filename">{getFilename(single()!.relativePath)}</span>
                     </Show>
                   </div>
-                  <Show when={!pending() && single()!.relativePath.includes("/")}>
+                  <Show when={!pending() && getDirectory(single()!.relativePath)}>
                     <div data-slot="message-part-path">
                       <span data-slot="message-part-directory">{getDirectory(single()!.relativePath)}</span>
                     </div>
diff --git a/packages/ui/src/components/session-review.tsx b/packages/ui/src/components/session-review.tsx
index 83d2980f61a2..7d75a13148f4 100644
--- a/packages/ui/src/components/session-review.tsx
+++ b/packages/ui/src/components/session-review.tsx
@@ -9,9 +9,10 @@ import { IconButton } from "./icon-button"
 import { StickyAccordionHeader } from "./sticky-accordion-header"
 import { Tooltip } from "./tooltip"
 import { ScrollView } from "./scroll-view"
+import { useData } from "../context"
 import { useFileComponent } from "../context/file"
 import { useI18n } from "../context/i18n"
-import { getDirectory, getFilename } from "@opencode-ai/util/path"
+import { getDirectory, getFilename, getRelativeDisplayPath, pathEqual, pathKey } from "@opencode-ai/util/path"
 import { checksum } from "@opencode-ai/util/encode"
 import { createEffect, createMemo, For, Match, Show, Switch, untrack, type JSX } from "solid-js"
 import { onCleanup } from "solid-js"
@@ -132,9 +133,12 @@ type SessionReviewSelection = {
   range: SelectedLineRange
 }
 
+const key = (path: string) => pathKey(path)
+
 export const SessionReview = (props: SessionReviewProps) => {
   let scroll: HTMLDivElement | undefined
   let focusToken = 0
+  const data = useData()
   const i18n = useI18n()
   const fileComponent = useFileComponent()
   const anchors = new Map<string, HTMLElement>()
@@ -151,9 +155,10 @@ export const SessionReview = (props: SessionReviewProps) => {
 
   const open = () => props.open ?? store.open
   const files = createMemo(() => props.diffs.map((diff) => diff.file))
-  const diffs = createMemo(() => new Map(props.diffs.map((diff) => [diff.file, diff] as const)))
+  const diffs = createMemo(() => new Map(props.diffs.map((diff) => [key(diff.file), diff] as const)))
   const diffStyle = () => props.diffStyle ?? (props.split ? "split" : "unified")
   const hasDiffs = () => files().length > 0
+  const visible = createMemo(() => files().filter((file) => open().some((item) => pathEqual(item, file))))
 
   const handleChange = (open: string[]) => {
     props.onOpenChange?.(open)
@@ -162,7 +167,7 @@ export const SessionReview = (props: SessionReviewProps) => {
   }
 
   const handleExpandOrCollapseAll = () => {
-    const next = open().length > 0 ? [] : files()
+    const next = visible().length > 0 ? [] : files()
     handleChange(next)
   }
 
@@ -188,11 +193,11 @@ export const SessionReview = (props: SessionReviewProps) => {
 
       setStore("opened", focus)
 
-      const comment = (props.comments ?? []).find((c) => c.file === focus.file && c.id === focus.id)
+      const comment = (props.comments ?? []).find((c) => pathEqual(c.file, focus.file) && c.id === focus.id)
       if (comment) setStore("selection", { file: comment.file, range: cloneSelectedLineRange(comment.selection) })
 
       const current = open()
-      if (!current.includes(focus.file)) {
+      if (!current.some((item) => pathEqual(item, focus.file))) {
         handleChange([...current, focus.file])
       }
 
@@ -202,7 +207,7 @@ export const SessionReview = (props: SessionReviewProps) => {
         const root = scroll
         if (!root) return
 
-        const wrapper = anchors.get(focus.file)
+        const wrapper = anchors.get(key(focus.file))
         const anchor = wrapper?.querySelector(`[data-comment-id="${focus.id}"]`)
         const ready =
           anchor instanceof HTMLElement && anchor.style.pointerEvents !== "none" && anchor.style.opacity !== "0"
@@ -258,7 +263,7 @@ export const SessionReview = (props: SessionReviewProps) => {
               onClick={handleExpandOrCollapseAll}
             >
               <Switch>
-                <Match when={open().length > 0}>{i18n.t("ui.sessionReview.collapseAll")}</Match>
+                <Match when={visible().length > 0}>{i18n.t("ui.sessionReview.collapseAll")}</Match>
                 <Match when={true}>{i18n.t("ui.sessionReview.expandAll")}</Match>
               </Switch>
             </Button>
@@ -281,17 +286,18 @@ export const SessionReview = (props: SessionReviewProps) => {
         <div data-slot="session-review-container" class={props.classes?.container}>
           <Show when={hasDiffs()} fallback={props.empty}>
             <div class="pb-6">
-              <Accordion multiple value={open()} onChange={handleChange}>
+              <Accordion multiple value={visible()} onChange={handleChange}>
                 <For each={files()}>
                   {(file) => {
                     let wrapper: HTMLDivElement | undefined
 
-                    const item = createMemo(() => diffs().get(file)!)
+                    const item = createMemo(() => diffs().get(key(file))!)
+                    const dir = createMemo(() => getDirectory(getRelativeDisplayPath(file, data.directory)))
 
-                    const expanded = createMemo(() => open().includes(file))
+                    const expanded = createMemo(() => open().some((item) => pathEqual(item, file)))
                     const force = () => !!store.force[file]
 
-                    const comments = createMemo(() => (props.comments ?? []).filter((c) => c.file === file))
+                    const comments = createMemo(() => (props.comments ?? []).filter((c) => pathEqual(c.file, file)))
                     const commentedLines = createMemo(() => comments().map((c) => c.selection))
 
                     const beforeText = () => (typeof item().before === "string" ? item().before : "")
@@ -313,13 +319,13 @@ export const SessionReview = (props: SessionReviewProps) => {
 
                     const selectedLines = createMemo(() => {
                       const current = selection()
-                      if (!current || current.file !== file) return null
+                      if (!current || !pathEqual(current.file, file)) return null
                       return current.range
                     })
 
                     const draftRange = createMemo(() => {
                       const current = commenting()
-                      if (!current || current.file !== file) return null
+                      if (!current || !pathEqual(current.file, file)) return null
                       return current.range
                     })
 
@@ -330,7 +336,7 @@ export const SessionReview = (props: SessionReviewProps) => {
                       state: {
                         opened: () => {
                           const current = opened()
-                          if (!current || current.file !== file) return null
+                          if (!current || !pathEqual(current.file, file)) return null
                           return current.id
                         },
                         setOpened: (id) => setStore("opened", id ? { file, id } : null),
@@ -377,7 +383,7 @@ export const SessionReview = (props: SessionReviewProps) => {
                     })
 
                     onCleanup(() => {
-                      anchors.delete(file)
+                      anchors.delete(key(file))
                     })
 
                     const handleLineSelected = (range: SelectedLineRange | null) => {
@@ -396,7 +402,7 @@ export const SessionReview = (props: SessionReviewProps) => {
                         id={diffId(file)}
                         data-file={file}
                         data-slot="session-review-accordion-item"
-                        data-selected={props.focusedFile === file ? "" : undefined}
+                        data-selected={props.focusedFile && pathEqual(props.focusedFile, file) ? "" : undefined}
                       >
                         <StickyAccordionHeader>
                           <Accordion.Trigger>
@@ -404,8 +410,8 @@ export const SessionReview = (props: SessionReviewProps) => {
                               <div data-slot="session-review-file-info">
                                 <FileIcon node={{ path: file, type: "file" }} />
                                 <div data-slot="session-review-file-name-container">
-                                  <Show when={file.includes("/")}>
-                                    <span data-slot="session-review-directory">{`\u202A${getDirectory(file)}\u202C`}</span>
+                                  <Show when={dir()}>
+                                    <span data-slot="session-review-directory">{`\u202A${dir()}\u202C`}</span>
                                   </Show>
                                   <span data-slot="session-review-filename">{getFilename(file)}</span>
                                   <Show when={props.onViewFile}>
@@ -461,7 +467,7 @@ export const SessionReview = (props: SessionReviewProps) => {
                             data-slot="session-review-diff-wrapper"
                             ref={(el) => {
                               wrapper = el
-                              anchors.set(file, el)
+                              anchors.set(key(file), el)
                             }}
                           >
                             <Show when={expanded()}>
diff --git a/packages/ui/src/components/session-turn.tsx b/packages/ui/src/components/session-turn.tsx
index 8c9c1ffe4030..a34053c3962c 100644
--- a/packages/ui/src/components/session-turn.tsx
+++ b/packages/ui/src/components/session-turn.tsx
@@ -4,7 +4,7 @@ import { useData } from "../context"
 import { useFileComponent } from "../context/file"
 
 import { Binary } from "@opencode-ai/util/binary"
-import { getDirectory, getFilename } from "@opencode-ai/util/path"
+import { getDirectory, getFilename, getRelativeDisplayPath, pathEqual, pathKey } from "@opencode-ai/util/path"
 import { createEffect, createMemo, createSignal, For, on, ParentProps, Show } from "solid-js"
 import { createStore } from "solid-js/store"
 import { Dynamic } from "solid-js/web"
@@ -87,6 +87,8 @@ function list<T>(value: T[] | undefined | null, fallback: T[]) {
 
 const hidden = new Set(["todowrite", "todoread"])
 
+const key = (path: string) => pathKey(path)
+
 function partState(part: PartType, showReasoningSummaries: boolean) {
   if (part.type === "tool") {
     if (hidden.has(part.tool)) return
@@ -233,8 +235,9 @@ export function SessionTurn(
     const seen = new Set<string>()
     return files
       .reduceRight<FileDiff[]>((result, diff) => {
-        if (seen.has(diff.file)) return result
-        seen.add(diff.file)
+        const id = key(diff.file)
+        if (seen.has(id)) return result
+        seen.add(id)
         result.push(diff)
         return result
       }, [])
@@ -247,6 +250,11 @@ export function SessionTurn(
   })
   const open = () => state.open
   const expanded = () => state.expanded
+  const visible = createMemo(() =>
+    diffs()
+      .map((diff) => diff.file)
+      .filter((file) => expanded().some((item) => pathEqual(item, file))),
+  )
 
   createEffect(
     on(
@@ -451,14 +459,15 @@ export function SessionTurn(
                           <Accordion
                             multiple
                             style={{ "--sticky-accordion-offset": "40px" }}
-                            value={expanded()}
+                            value={visible()}
                             onChange={(value) =>
                               setState("expanded", Array.isArray(value) ? value : value ? [value] : [])
                             }
                           >
                             <For each={diffs()}>
                               {(diff) => {
-                                const active = createMemo(() => expanded().includes(diff.file))
+                                const active = createMemo(() => expanded().some((item) => pathEqual(item, diff.file)))
+                                const dir = createMemo(() => getDirectory(getRelativeDisplayPath(diff.file, data.directory)))
                                 const [visible, setVisible] = createSignal(false)
 
                                 createEffect(
@@ -485,10 +494,8 @@ export function SessionTurn(
                                       <Accordion.Trigger>
                                         <div data-slot="session-turn-diff-trigger">
                                           <span data-slot="session-turn-diff-path">
-                                            <Show when={diff.file.includes("/")}>
-                                              <span data-slot="session-turn-diff-directory">
-                                                {`\u202A${getDirectory(diff.file)}\u202C`}
-                                              </span>
+                                            <Show when={dir()}>
+                                              <span data-slot="session-turn-diff-directory">{`\u202A${dir()}\u202C`}</span>
                                             </Show>
                                             <span data-slot="session-turn-diff-filename">{getFilename(diff.file)}</span>
                                           </span>
diff --git a/packages/ui/src/context/data.tsx b/packages/ui/src/context/data.tsx
index e116199eb233..b5b67a94e4e9 100644
--- a/packages/ui/src/context/data.tsx
+++ b/packages/ui/src/context/data.tsx
@@ -1,8 +1,9 @@
-import type { Message, Session, Part, FileDiff, SessionStatus, ProviderListResponse } from "@opencode-ai/sdk/v2"
+import type { FileDiff, Message, Part, Path, ProviderListResponse, Session, SessionStatus } from "@opencode-ai/sdk/v2"
 import { createSimpleContext } from "./helper"
 import { PreloadMultiFileDiffResult } from "@pierre/diffs/ssr"
 
 type Data = {
+  path?: Path
   provider?: ProviderListResponse
   session: Session[]
   session_status: {
@@ -41,6 +42,9 @@ export const { use: useData, provider: DataProvider } = createSimpleContext({
       get directory() {
         return props.directory
       },
+      get path() {
+        return props.data.path
+      },
       navigateToSession: props.onNavigateToSession,
       sessionHref: props.onSessionHref,
     }
diff --git a/packages/util/src/path.test.ts b/packages/util/src/path.test.ts
new file mode 100644
index 000000000000..d227f9b9e4b7
--- /dev/null
+++ b/packages/util/src/path.test.ts
@@ -0,0 +1,140 @@
+import { describe, expect, test } from "bun:test"
+import {
+  decodeFilePath,
+  encodeFilePath,
+  getDirectory,
+  getFilename,
+  joinPath,
+  normalizeInputPath,
+  getParentPath,
+  getPathDisplay,
+  getPathDisplaySeparator,
+  getPathRoot,
+  getPathScope,
+  getPathSearchText,
+  getPathSeparator,
+  getRelativeDisplayPath,
+  getWorkspaceRelativePath,
+  resolveWorkspacePath,
+  stripFileProtocol,
+  stripQueryAndHash,
+  trimPath,
+  trimPrettyPath,
+  unquoteGitPath,
+} from "./path"
+
+describe("path display helpers", () => {
+  test("keeps posix separators in displayed directories", () => {
+    expect(getDirectory("src/components/app.tsx")).toBe("src/components/")
+    expect(getDirectory("/tmp/demo/app.ts")).toBe("/tmp/demo/")
+  })
+
+  test("keeps windows separators in displayed directories", () => {
+    expect(getDirectory("src\\components\\app.tsx")).toBe("src\\components\\")
+    expect(getDirectory("C:\\repo\\src\\app.tsx")).toBe("C:\\repo\\src\\")
+    expect(getDirectory("\\\\server\\share\\repo\\app.tsx")).toBe("\\\\server\\share\\repo\\")
+  })
+
+  test("extracts filenames across separator styles", () => {
+    expect(getFilename("src/components/app.tsx")).toBe("app.tsx")
+    expect(getFilename("src\\components\\app.tsx")).toBe("app.tsx")
+  })
+
+  test("infers native-looking separators for windows paths", () => {
+    expect(getPathSeparator("/tmp/demo")).toBe("/")
+    expect(getPathSeparator("C:/repo/src/app.tsx")).toBe("\\")
+    expect(getPathSeparator("\\\\server\\share\\repo")).toBe("\\")
+  })
+
+  test("keeps UNC roots stable for lexical navigation", () => {
+    expect(getPathRoot("\\\\server\\share\\repo")).toBe("//server/share")
+    expect(getPathRoot("\\\\server\\share")).toBe("//server/share")
+    expect(getParentPath("//server/share/repo")).toBe("//server/share")
+    expect(getParentPath("\\\\server\\share")).toBe("//server/share")
+  })
+
+  test("keeps windows root forms stable for lexical navigation", () => {
+    expect(getPathRoot("C:")).toBe("C:/")
+    expect(getParentPath("C:")).toBe("C:/")
+    expect(getParentPath("C:/")).toBe("C:/")
+  })
+
+  test("normalizes input paths separately from pretty stored paths", () => {
+    expect(normalizeInputPath("C:")).toBe("C:/")
+    expect(trimPath("\\\\server\\share\\repo\\")).toBe("//server/share/repo")
+    expect(trimPrettyPath("C:/Users/dev/repo/")).toBe("C:\\Users\\dev\\repo")
+    expect(trimPrettyPath("\\\\server\\share\\repo\\")).toBe("\\\\server\\share\\repo")
+  })
+
+  test("joins pretty paths with native separators", () => {
+    expect(joinPath("/Users/dev", "repo/src")).toBe("/Users/dev/repo/src")
+    expect(joinPath("C:\\Users\\dev", "repo/src")).toBe("C:\\Users\\dev\\repo\\src")
+    expect(joinPath("\\\\server\\share", "repo")).toBe("\\\\server\\share\\repo")
+    expect(joinPath("C:\\Users\\dev", "C:/tmp/demo")).toBe("C:\\tmp\\demo")
+  })
+
+  test("builds picker display text with tilde and native separators", () => {
+    expect(getPathDisplay("/Users/dev/repo", "", "/Users/dev")).toBe("~/repo")
+    expect(getPathDisplaySeparator("~/repo", "/Users/dev")).toBe("/")
+    expect(getPathDisplay("C:/Users/dev/repo", "", "C:\\Users\\dev")).toBe("~\\repo")
+    expect(getPathDisplay("//server/share/repo", "\\\\server\\", "C:\\Users\\dev")).toBe(
+      "\\\\server\\share\\repo",
+    )
+  })
+
+  test("scopes picker input from home or absolute roots", () => {
+    expect(getPathScope("\\\\server\\share\\repo", "C:/Users/dev", "C:/Users/dev")).toEqual({
+      directory: "\\\\server\\share",
+      path: "repo",
+    })
+    expect(getPathScope("~/code", "C:/Users/dev", "C:/Users/dev")).toEqual({
+      directory: "C:\\Users\\dev",
+      path: "code",
+    })
+  })
+
+  test("indexes search text in absolute, native, and filename forms", () => {
+    const search = getPathSearchText("//server/share/repo", "C:\\Users\\dev")
+    expect(search).toContain("//server/share/repo")
+    expect(search).toContain("\\\\server\\share\\repo")
+    expect(search).toContain("repo")
+  })
+
+  test("relativizes display paths from the workspace root", () => {
+    expect(getRelativeDisplayPath("/repo/src/app.ts", "/repo")).toBe("/src/app.ts")
+    expect(getRelativeDisplayPath("C:\\repo\\src\\", "C:\\repo")).toBe("\\src\\")
+    expect(getRelativeDisplayPath("src/app.ts", "C:\\repo")).toBe("src\\app.ts")
+    expect(getRelativeDisplayPath("src\\app.ts", "/repo")).toBe("src/app.ts")
+    expect(getRelativeDisplayPath("C:/other/app.ts", "C:\\repo")).toBe("C:\\other\\app.ts")
+    expect(getRelativeDisplayPath("/other/app.ts", "/repo")).toBe("/other/app.ts")
+  })
+
+  test("resolves and relativizes workspace paths across platforms", () => {
+    expect(resolveWorkspacePath("/repo", "src/app.ts")).toBe("/repo/src/app.ts")
+    expect(resolveWorkspacePath("C:\\repo", "src\\app.ts")).toBe("C:\\repo\\src\\app.ts")
+    expect(resolveWorkspacePath("\\\\server\\share\\repo", "src\\app.ts")).toBe("\\\\server\\share\\repo\\src\\app.ts")
+    expect(resolveWorkspacePath("/repo", "/tmp/app.ts")).toBe("/tmp/app.ts")
+
+    expect(getWorkspaceRelativePath("/repo/src/app.ts", "/repo")).toBe("src/app.ts")
+    expect(getWorkspaceRelativePath("C:/repo/src/app.ts", "C:\\repo")).toBe("src/app.ts")
+    expect(getWorkspaceRelativePath("c:\\repo\\src\\app.ts", "C:\\repo")).toBe("src\\app.ts")
+    expect(getWorkspaceRelativePath("//server/share/repo/src/app.ts", "\\\\server\\share\\repo")).toBe("src/app.ts")
+    expect(getWorkspaceRelativePath("/tmp/app.ts", "/repo")).toBe("/tmp/app.ts")
+  })
+
+  test("handles shared file-uri and git path decoding", () => {
+    expect(stripFileProtocol("file:///repo/src/app.ts")).toBe("/repo/src/app.ts")
+    expect(stripQueryAndHash("a/b.ts#L12?x=1")).toBe("a/b.ts")
+    expect(stripQueryAndHash("a/b.ts?x=1#L12")).toBe("a/b.ts")
+    expect(decodeFilePath("src/file%23name%20here.ts")).toBe("src/file#name here.ts")
+    expect(decodeFilePath("src/%ZZ/file.ts")).toBe("src/%ZZ/file.ts")
+    expect(unquoteGitPath('"a/\\303\\251.txt"')).toBe("a/\u00e9.txt")
+    expect(unquoteGitPath('"plain\\nname"')).toBe("plain\nname")
+  })
+
+  test("encodes file paths for file URIs", () => {
+    expect(encodeFilePath("/path/to/file#name.txt")).toBe("/path/to/file%23name.txt")
+    expect(encodeFilePath("C:\\Users\\test\\file with spaces.txt")).toBe("/C:/Users/test/file%20with%20spaces.txt")
+    expect(encodeFilePath("src\\app.ts")).toBe("src/app.ts")
+  })
+})
diff --git a/packages/util/src/path.ts b/packages/util/src/path.ts
index bb191f5120ab..72dda884a9ed 100644
--- a/packages/util/src/path.ts
+++ b/packages/util/src/path.ts
@@ -1,3 +1,12 @@
+/**
+ * UI/string-oriented path helpers shared across packages.
+ *
+ * This file normalizes separators, display text, and lightweight comparisons,
+ * but it is not the source of truth for filesystem-aware resolution,
+ * `file://` parsing, or Windows alias handling. Those semantics live in
+ * `packages/opencode/src/path/path.ts`.
+ */
+
 export function getFilename(path: string | undefined) {
   if (!path) return ""
   const trimmed = path.replace(/[\/\\]+$/, "")
@@ -5,11 +14,379 @@ export function getFilename(path: string | undefined) {
   return parts[parts.length - 1] ?? ""
 }
 
+const normalizeSlashes = (path: string) => path.replace(/[\\/]+/g, "/")
+
+const isUncPath = (path: string) => /^[\\/]{2}[^\\/]/.test(path)
+
+const isWindowsDrivePath = (path: string) => /^[A-Za-z]:([\\/]|$)/.test(path)
+
+const normalizeDrive = (path: string) => {
+  const normalized = normalizePath(path)
+  if (/^[A-Za-z]:$/.test(normalized)) return `${normalized}/`
+  return normalized
+}
+
+const trimDisplay = (path: string) => {
+  const separator = getPathSeparator(path)
+  return separator === "/" ? path : path.replaceAll("/", "\\")
+}
+
+export function normalizeInputPath(path: string) {
+  return normalizeDrive(path)
+}
+
+export function trimPath(path: string) {
+  const normalized = normalizeDrive(path)
+  if (normalized === "/" || normalized === "//") return normalized
+  if (/^[A-Za-z]:\/$/.test(normalized)) return normalized
+  return normalized.replace(/\/+$/, "")
+}
+
+export function trimPrettyPath(path: string) {
+  const trimmed = trimPath(path)
+  if (!trimmed) return ""
+  return trimDisplay(trimmed)
+}
+
+export function joinPath(base: string | undefined, path: string) {
+  if (getPathRoot(path)) return trimPrettyPath(path)
+
+  const root = trimPrettyPath(base ?? "")
+  const leaf = trimPath(path).replace(/^\/+/, "")
+  if (!root) return trimDisplay(leaf)
+  if (!leaf) return root
+
+  const separator = getPathSeparator(root)
+  const value = separator === "/" ? leaf : leaf.replaceAll("/", "\\")
+  if (root.endsWith(separator)) return root + value
+  return `${root}${separator}${value}`
+}
+
+const mode = (path: string) => {
+  const normalized = normalizeDrive(path.trim())
+  if (!normalized) return "relative" as const
+  if (normalized.startsWith("~")) return "tilde" as const
+  if (getPathRoot(normalized)) return "absolute" as const
+  return "relative" as const
+}
+
+const fold = (path: string) => {
+  const normalized = normalizePath(path)
+  if (isWindowsDrivePath(normalized) || isUncPath(normalized)) return normalized.toLowerCase()
+  return normalized
+}
+
+const native = (path: string, home: string) => {
+  if (getPathDisplaySeparator(path, home) === "/") return path
+  return path.replaceAll("/", "\\")
+}
+
+const trailing = (path: string, home: string) => {
+  if (!path) return ""
+  const separator = getPathDisplaySeparator(path, home)
+  if (path.endsWith(separator)) return path
+  return path + separator
+}
+
+const resep = (path: string, separator: "/" | "\\", trailing: boolean) => {
+  const text = normalizePath(path).replace(/\/+$/, "")
+  if (!text) return trailing ? separator : ""
+  const value = separator === "/" ? text : text.replaceAll("/", "\\")
+  return trailing ? value + separator : value
+}
+
+export function normalizePath(path: string) {
+  if (!path) return ""
+  if (isUncPath(path)) return `//${path.slice(2).replace(/[\\/]+/g, "/")}`
+  return normalizeSlashes(path)
+}
+
+export function stripFileProtocol(input: string) {
+  if (!input.startsWith("file://")) return input
+  return input.slice("file://".length)
+}
+
+export function stripQueryAndHash(input: string) {
+  const hash = input.indexOf("#")
+  const query = input.indexOf("?")
+
+  if (hash !== -1 && query !== -1) {
+    return input.slice(0, Math.min(hash, query))
+  }
+
+  if (hash !== -1) return input.slice(0, hash)
+  if (query !== -1) return input.slice(0, query)
+  return input
+}
+
+export function unquoteGitPath(input: string) {
+  if (!input.startsWith('"')) return input
+  if (!input.endsWith('"')) return input
+  const body = input.slice(1, -1)
+  const bytes: number[] = []
+
+  for (let i = 0; i < body.length; i++) {
+    const char = body[i]!
+    if (char !== "\\") {
+      bytes.push(char.charCodeAt(0))
+      continue
+    }
+
+    const next = body[i + 1]
+    if (!next) {
+      bytes.push("\\".charCodeAt(0))
+      continue
+    }
+
+    if (next >= "0" && next <= "7") {
+      const chunk = body.slice(i + 1, i + 4)
+      const match = chunk.match(/^[0-7]{1,3}/)
+      if (!match) {
+        bytes.push(next.charCodeAt(0))
+        i++
+        continue
+      }
+      bytes.push(parseInt(match[0], 8))
+      i += match[0].length
+      continue
+    }
+
+    const escaped =
+      next === "n"
+        ? "\n"
+        : next === "r"
+          ? "\r"
+          : next === "t"
+            ? "\t"
+            : next === "b"
+              ? "\b"
+              : next === "f"
+                ? "\f"
+                : next === "v"
+                  ? "\v"
+                  : next === "\\" || next === '"'
+                    ? next
+                    : undefined
+
+    bytes.push((escaped ?? next).charCodeAt(0))
+    i++
+  }
+
+  return new TextDecoder().decode(new Uint8Array(bytes))
+}
+
+export function decodeFilePath(input: string) {
+  try {
+    return decodeURIComponent(input)
+  } catch {
+    return input
+  }
+}
+
+export function resolveWorkspacePath(root: string, path: string) {
+  if (!path) return path
+  if (getPathRoot(path)) return path
+  if (!root) return path
+
+  const base = root.replace(/[\\/]+$/, "")
+  if (base) return `${base}${getPathSeparator(root)}${path}`
+
+  const prefix = trimPath(root)
+  if (!prefix) return path
+  if (prefix.endsWith("/")) return prefix + path
+  return `${prefix}/${path}`
+}
+
+export function getWorkspaceRelativePath(path: string, root: string) {
+  if (!root) return path
+
+  const base = trimPath(root)
+  if (!base) return path
+
+  const windows = isWindowsDrivePath(base) || isUncPath(base)
+  const canonRoot = windows ? base.replace(/\\/g, "/").toLowerCase() : base.replace(/\\/g, "/")
+  const canonPath = windows ? path.replace(/\\/g, "/").toLowerCase() : path.replace(/\\/g, "/")
+
+  if (!canonPath.startsWith(canonRoot)) return path
+  if (!canonRoot.endsWith("/")) {
+    const next = canonPath[canonRoot.length]
+    if (next && next !== "/") return path
+  }
+
+  return path.slice(base.length).replace(/^[\\/]+/, "")
+}
+
+export function getPathSeparator(path: string | undefined) {
+  if (!path) return "/"
+  if (path.includes("\\") || isWindowsDrivePath(path) || isUncPath(path)) return "\\"
+  return "/"
+}
+
+export function getPathRoot(path: string) {
+  const normalized = normalizeDrive(path)
+  if (normalized.startsWith("//")) {
+    const parts = normalized
+      .slice(2)
+      .replace(/^\/+/, "")
+      .split("/")
+      .filter(Boolean)
+    if (parts.length === 0) return "//"
+    if (parts.length === 1) return `//${parts[0]}`
+    return `//${parts[0]}/${parts[1]}`
+  }
+  if (normalized.startsWith("/")) return "/"
+  if (/^[A-Za-z]:\//.test(normalized)) return normalized.slice(0, 3)
+  return ""
+}
+
+export function pathKey(path: string) {
+  if (!path) return ""
+
+  if (isUncPath(path)) {
+    const normalized = normalizeSlashes(path).replace(/^\/+/, "").replace(/\/+$/, "")
+    return normalized ? `//${normalized.toLowerCase()}` : "//"
+  }
+
+  const normalized = normalizeSlashes(path).replace(/\/+$/, "")
+
+  if (isWindowsDrivePath(path)) {
+    const folded = normalized.toLowerCase()
+    return /^[a-z]:$/.test(folded) ? `${folded}/` : folded
+  }
+
+  if (!normalized && /[\\/]/.test(path)) return "/"
+  return normalized
+}
+
+export function pathEqual(a: string | undefined, b: string | undefined) {
+  if (!a || !b) return a === b
+  return pathKey(a) === pathKey(b)
+}
+
+export function getParentPath(path: string) {
+  if (!path) return ""
+  const normalized = trimPath(path)
+  if (normalized === "/" || normalized === "//") return normalized
+  if (/^[A-Za-z]:\/$/.test(normalized)) return normalized
+
+  const root = getPathRoot(normalized)
+  if (root && normalized === root) return root
+
+  const idx = normalized.lastIndexOf("/")
+  if (idx < 0) return root
+  if (idx === 0) return "/"
+  if (idx === 2 && /^[A-Za-z]:/.test(normalized)) return normalized.slice(0, 3)
+
+  const parent = normalized.slice(0, idx)
+  if (root && parent.length < root.length) return root
+  return parent || root || "/"
+}
+
+const getTildePath = (path: string, home: string) => {
+  const full = trimPath(path)
+  const base = trimPath(home)
+  if (!base) return ""
+  if (fold(full) === fold(base)) return "~"
+  if (fold(full).startsWith(fold(base + "/"))) return `~${full.slice(base.length)}`
+  return ""
+}
+
+export function getPathDisplaySeparator(path: string, home: string) {
+  if (mode(path) === "absolute") return getPathSeparator(path)
+  return getPathSeparator(home || path)
+}
+
+export function getPathDisplay(path: string, input: string, home: string) {
+  const full = trimPath(path)
+  const value = mode(input) === "absolute" ? full : getTildePath(full, home) || full
+  return native(value, home)
+}
+
+export function getPathSearchText(path: string, home: string) {
+  const full = trimPath(path)
+  const tilde = getTildePath(full, home)
+  const absolute = native(full, home)
+  const shown = tilde ? native(tilde, home) : ""
+
+  return Array.from(
+    new Set(
+      [
+        full,
+        trailing(full, home),
+        absolute,
+        trailing(absolute, home),
+        tilde,
+        trailing(tilde, home),
+        shown,
+        trailing(shown, home),
+        getFilename(full),
+      ].filter(Boolean),
+    ),
+  ).join("\n")
+}
+
+export function getPathScope(input: string, start: string | undefined, home: string) {
+  const base = start ? trimPrettyPath(start) : ""
+  if (!base) return
+
+  const normalized = normalizeInputPath(input)
+  if (!normalized) return { directory: base, path: "" }
+  if (normalized === "~") return { directory: trimPrettyPath(home || base), path: "" }
+  if (normalized.startsWith("~/")) return { directory: trimPrettyPath(home || base), path: normalized.slice(2) }
+
+  const root = getPathRoot(normalized)
+  if (!root) return { directory: base, path: normalized }
+  return {
+    directory: trimPrettyPath(root),
+    path: normalized.slice(root.length).replace(/^\/+/, ""),
+  }
+}
+
+export function getRelativeDisplayPath(path: string, root?: string) {
+  if (!path) return ""
+  if (!root) return path
+  if (root === "/" || root === "\\") return resep(path, getPathSeparator(root), /[\\/]+$/.test(path))
+
+  const separator = getPathSeparator(root)
+  const trailing = /[\\/]+$/.test(path)
+  const full = normalizePath(path).replace(/\/+$/, "")
+  const base = normalizePath(root).replace(/\/+$/, "")
+  if (!base) return resep(path, separator, trailing)
+  if (!getPathRoot(full)) return resep(full, separator, trailing)
+  if (fold(full) === fold(base)) return trailing ? separator : ""
+
+  const prefix = `${base}/`
+  if (!fold(full).startsWith(fold(prefix))) return resep(full, separator, trailing)
+
+  const relative = full.slice(base.length).replace(/^\/+/, "")
+  if (!relative) return trailing ? separator : ""
+
+  const value = separator + relative.replaceAll("/", separator)
+  return trailing ? value + separator : value
+}
+
+export function encodeFilePath(filepath: string): string {
+  let normalized = filepath.replace(/\\/g, "/")
+
+  if (/^[A-Za-z]:/.test(normalized)) {
+    normalized = "/" + normalized
+  }
+
+  return normalized
+    .split("/")
+    .map((segment, index) => {
+      if (index === 1 && /^[A-Za-z]:$/.test(segment)) return segment
+      return encodeURIComponent(segment)
+    })
+    .join("/")
+}
+
 export function getDirectory(path: string | undefined) {
   if (!path) return ""
   const trimmed = path.replace(/[\/\\]+$/, "")
-  const parts = trimmed.split(/[\/\\]/)
-  return parts.slice(0, parts.length - 1).join("/") + "/"
+  const idx = Math.max(trimmed.lastIndexOf("/"), trimmed.lastIndexOf("\\"))
+  if (idx < 0) return ""
+  return trimmed.slice(0, idx + 1) || getPathSeparator(path)
 }
 
 export function getFileExtension(path: string | undefined) {