diff --git a/packages/opencode/src/cli/cmd/tui/component/prompt/autocomplete-slash.test.ts b/packages/opencode/src/cli/cmd/tui/component/prompt/autocomplete-slash.test.ts
new file mode 100644
index 000000000000..533a6fa3624b
--- /dev/null
+++ b/packages/opencode/src/cli/cmd/tui/component/prompt/autocomplete-slash.test.ts
@@ -0,0 +1,27 @@
+import { describe, expect, test } from "bun:test"
+import { scan, splice } from "./autocomplete-slash"
+
+describe("autocomplete slash", () => {
+  test("scans the slash token at the caret", () => {
+    expect(scan("/open", 5)).toEqual({ start: 0, end: 5, query: "open" })
+    expect(scan("hello /ope", 10)).toEqual({ start: 6, end: 10, query: "ope" })
+    expect(scan("hello/open", 10)).toEqual({ start: 5, end: 10, query: "open" })
+    expect(scan("hello /nested/child tail", 19)).toEqual({ start: 6, end: 19, query: "nested/child" })
+  })
+
+  test("ignores spaces after the slash token", () => {
+    expect(scan("hello /open ", 12)).toBeUndefined()
+    expect(scan("hello world", 11)).toBeUndefined()
+    expect(scan("/open", 0)).toBeUndefined()
+  })
+
+  test("splices inline slash text", () => {
+    expect(splice("hello /open", 6, 11, "")).toBe("hello ")
+    expect(splice("hello/open", 5, 10, "")).toBe("hello")
+  })
+
+  test("can move a custom command to the front", () => {
+    const text = splice("hello /rev", 6, 10, "")
+    expect(splice(text, 0, 0, "/review ")).toBe("/review hello ")
+  })
+})
diff --git a/packages/opencode/src/cli/cmd/tui/component/prompt/autocomplete-slash.ts b/packages/opencode/src/cli/cmd/tui/component/prompt/autocomplete-slash.ts
new file mode 100644
index 000000000000..3bc576690335
--- /dev/null
+++ b/packages/opencode/src/cli/cmd/tui/component/prompt/autocomplete-slash.ts
@@ -0,0 +1,30 @@
+export type Slash = {
+  start: number
+  end: number
+  query: string
+}
+
+const blank = (char: string) => /\s/.test(char)
+const slash = /\/(\S*)$/
+
+export function scan(text: string, cursor: number) {
+  if (cursor <= 0 || cursor > text.length) return
+
+  const match = text.slice(0, cursor).match(slash)
+  if (!match) return
+
+  const start = match.index ?? cursor - match[0].length
+  let end = cursor
+
+  while (end < text.length && !blank(text[end]!)) end += 1
+
+  return {
+    start,
+    end,
+    query: text.slice(start + 1, cursor),
+  } satisfies Slash
+}
+
+export function splice(text: string, start: number, end: number, next: string) {
+  return text.slice(0, start) + next + text.slice(end)
+}
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..2ba69839f735 100644
--- a/packages/opencode/src/cli/cmd/tui/component/prompt/autocomplete.tsx
+++ b/packages/opencode/src/cli/cmd/tui/component/prompt/autocomplete.tsx
@@ -12,6 +12,7 @@ import { useCommandDialog } from "@tui/component/dialog-command"
 import { useTerminalDimensions } from "@opentui/solid"
 import { Locale } from "@/util/locale"
 import type { PromptInfo } from "./history"
+import { scan } from "./autocomplete-slash"
 import { useFrecency } from "./frecency"
 
 function removeLineRange(input: string) {
@@ -140,6 +141,38 @@ export function Autocomplete(props: {
     setSearch(next ? next : "")
   })
 
+  function write() {
+    props.setPrompt((draft) => {
+      draft.input = props.input().plainText
+    })
+  }
+
+  function cut() {
+    if (store.visible !== "/") return
+
+    const input = props.input()
+    const hit = scan(input.plainText, input.cursorOffset)
+    if (!hit || hit.start !== store.index) return
+
+    input.cursorOffset = hit.start
+    const start = input.logicalCursor
+    input.cursorOffset = hit.end
+    const end = input.logicalCursor
+
+    input.deleteRange(start.row, start.col, end.row, end.col)
+    input.cursorOffset = hit.start
+    write()
+    return hit
+  }
+
+  function lead(text: string) {
+    const input = props.input()
+    input.cursorOffset = 0
+    input.insertText(text)
+    input.cursorOffset = Bun.stringWidth(input.plainText)
+    write()
+  }
+
   // When the filter changes due to how TUI works, the mousemove might still be triggered
   // via a synthetic event as the layout moves underneath the cursor. This is a workaround to make sure the input mode remains keyboard so
   // that the mouseover event doesn't trigger when filtering.
@@ -363,11 +396,7 @@ export function Autocomplete(props: {
         display: "/" + serverCommand.name + label,
         description: serverCommand.description,
         onSelect: () => {
-          const newText = "/" + serverCommand.name + " "
-          const cursor = props.input().logicalCursor
-          props.input().deleteRange(0, 0, cursor.row, cursor.col)
-          props.input().insertText(newText)
-          props.input().cursorOffset = Bun.stringWidth(newText)
+          lead("/" + serverCommand.name + " ")
         },
       })
     }
@@ -484,15 +513,7 @@ export function Autocomplete(props: {
   }
 
   function hide() {
-    const text = props.input().plainText
-    if (store.visible === "/" && !text.endsWith(" ") && text.startsWith("/")) {
-      const cursor = props.input().logicalCursor
-      props.input().deleteRange(0, 0, cursor.row, cursor.col)
-      // Sync the prompt store immediately since onContentChange is async
-      props.setPrompt((draft) => {
-        draft.input = props.input().plainText
-      })
-    }
+    cut()
     command.keybinds(true)
     setStore("visible", false)
   }
@@ -504,13 +525,17 @@ export function Autocomplete(props: {
       },
       onInput(value) {
         if (store.visible) {
+          if (store.visible === "/") {
+            const hit = scan(value, props.input().cursorOffset)
+            if (!hit || hit.start !== store.index) {
+              hide()
+            }
+            return
+          }
+
           if (
-            // Typed text before the trigger
             props.input().cursorOffset <= store.index ||
-            // There is a space between the trigger and the cursor
-            props.input().getTextRange(store.index, props.input().cursorOffset).match(/\s/) ||
-            // "/<command>" is not the sole content
-            (store.visible === "/" && value.match(/^\S+\s+\S+\s*$/))
+            props.input().getTextRange(store.index, props.input().cursorOffset).match(/\s/)
           ) {
             hide()
           }
@@ -521,10 +546,10 @@ export function Autocomplete(props: {
         const offset = props.input().cursorOffset
         if (offset === 0) return
 
-        // Check for "/" at position 0 - reopen slash commands
-        if (value.startsWith("/") && !value.slice(0, offset).match(/\s/)) {
+        const hit = scan(value, offset)
+        if (hit) {
           show("/")
-          setStore("index", 0)
+          setStore("index", hit.start)
           return
         }
 
@@ -590,7 +615,7 @@ export function Autocomplete(props: {
           }
 
           if (e.name === "/") {
-            if (props.input().cursorOffset === 0) show("/")
+            show("/")
           }
         }
       },
diff --git a/packages/opencode/src/cli/cmd/tui/component/prompt/edit.test.ts b/packages/opencode/src/cli/cmd/tui/component/prompt/edit.test.ts
new file mode 100644
index 000000000000..974a30ebecc8
--- /dev/null
+++ b/packages/opencode/src/cli/cmd/tui/component/prompt/edit.test.ts
@@ -0,0 +1,65 @@
+import { describe, expect, test } from "bun:test"
+import { lead } from "./edit"
+
+describe("prompt edit", () => {
+  test("leads prompt text and shifts parts", () => {
+    const next = lead(
+      {
+        input: "hello @build @src/app.ts [pasted]",
+        parts: [
+          {
+            type: "agent",
+            name: "build",
+            source: { start: 6, end: 12, value: "@build" },
+          },
+          {
+            type: "file",
+            mime: "text/plain",
+            filename: "src/app.ts",
+            url: "file:///src/app.ts",
+            source: {
+              type: "file",
+              path: "src/app.ts",
+              text: { start: 13, end: 24, value: "@src/app.ts" },
+            },
+          },
+          {
+            type: "text",
+            text: "pasted",
+            source: {
+              text: { start: 25, end: 33, value: "[pasted]" },
+            },
+          },
+        ],
+      },
+      "/skill ",
+    )
+
+    expect(next.input).toBe("/skill hello @build @src/app.ts [pasted]")
+    expect(next.parts).toEqual([
+      {
+        type: "agent",
+        name: "build",
+        source: { start: 13, end: 19, value: "@build" },
+      },
+      {
+        type: "file",
+        mime: "text/plain",
+        filename: "src/app.ts",
+        url: "file:///src/app.ts",
+        source: {
+          type: "file",
+          path: "src/app.ts",
+          text: { start: 20, end: 31, value: "@src/app.ts" },
+        },
+      },
+      {
+        type: "text",
+        text: "pasted",
+        source: {
+          text: { start: 32, end: 40, value: "[pasted]" },
+        },
+      },
+    ])
+  })
+})
diff --git a/packages/opencode/src/cli/cmd/tui/component/prompt/edit.ts b/packages/opencode/src/cli/cmd/tui/component/prompt/edit.ts
new file mode 100644
index 000000000000..a4908c8638ea
--- /dev/null
+++ b/packages/opencode/src/cli/cmd/tui/component/prompt/edit.ts
@@ -0,0 +1,52 @@
+import type { PromptInfo } from "./history"
+
+export function lead(prompt: PromptInfo, text: string): PromptInfo {
+  const size = Bun.stringWidth(text)
+
+  return {
+    ...prompt,
+    input: text + prompt.input,
+    parts: prompt.parts.map((part): PromptInfo["parts"][number] => {
+      if (part.type === "file" && part.source?.text) {
+        return {
+          ...part,
+          source: {
+            ...part.source,
+            text: {
+              ...part.source.text,
+              start: part.source.text.start + size,
+              end: part.source.text.end + size,
+            },
+          },
+        }
+      }
+
+      if (part.type === "text" && part.source?.text) {
+        return {
+          ...part,
+          source: {
+            ...part.source,
+            text: {
+              ...part.source.text,
+              start: part.source.text.start + size,
+              end: part.source.text.end + size,
+            },
+          },
+        }
+      }
+
+      if (part.type === "agent" && part.source) {
+        return {
+          ...part,
+          source: {
+            ...part.source,
+            start: part.source.start + size,
+            end: part.source.end + size,
+          },
+        }
+      }
+
+      return part
+    }),
+  }
+}
diff --git a/packages/opencode/src/cli/cmd/tui/component/prompt/index.tsx b/packages/opencode/src/cli/cmd/tui/component/prompt/index.tsx
index c85426cc2471..a074a0548210 100644
--- a/packages/opencode/src/cli/cmd/tui/component/prompt/index.tsx
+++ b/packages/opencode/src/cli/cmd/tui/component/prompt/index.tsx
@@ -14,6 +14,7 @@ import { createStore, produce } from "solid-js/store"
 import { useKeybind } from "@tui/context/keybind"
 import { usePromptHistory, type PromptInfo } from "./history"
 import { usePromptStash } from "./stash"
+import { lead } from "./edit"
 import { DialogStash } from "../dialog-stash"
 import { type AutocompleteRef, Autocomplete } from "./autocomplete"
 import { useCommandDialog } from "../dialog-command"
@@ -341,11 +342,11 @@ export function Prompt(props: PromptProps) {
           dialog.replace(() => (
             <DialogSkill
               onSelect={(skill) => {
-                input.setText(`/${skill} `)
-                setStore("prompt", {
-                  input: `/${skill} `,
-                  parts: [],
-                })
+                syncExtmarksWithPromptParts()
+                const next = lead(store.prompt, `/${skill} `)
+                input.setText(next.input)
+                setStore("prompt", next)
+                restoreExtmarksFromParts(next.parts)
                 input.gotoBufferEnd()
               }}
             />