diff --git a/packages/opencode/src/effect/cross-spawn-spawner.ts b/packages/opencode/src/effect/cross-spawn-spawner.ts
index 92e5b3ba2d07..dc081001e8bc 100644
--- a/packages/opencode/src/effect/cross-spawn-spawner.ts
+++ b/packages/opencode/src/effect/cross-spawn-spawner.ts
@@ -268,19 +268,34 @@ export const make = Effect.gen(function* () {
       const proc = launch(command.command, command.args, opts)
       let end = false
       let exit: readonly [code: number | null, signal: NodeJS.Signals | null] | undefined
+      let spawned = false
       proc.on("error", (err) => {
-        resume(Effect.fail(toPlatformError("spawn", err, command)))
+        if (!spawned) {
+          spawned = true
+          resume(Effect.fail(toPlatformError("spawn", err, command)))
+        }
       })
       proc.on("exit", (...args) => {
+        if (!spawned) {
+          spawned = true
+          resume(Effect.succeed([proc, signal]))
+        }
         exit = args
       })
       proc.on("close", (...args) => {
+        if (!spawned) {
+          spawned = true
+          resume(Effect.succeed([proc, signal]))
+        }
         if (end) return
         end = true
         Deferred.doneUnsafe(signal, Exit.succeed(exit ?? args))
       })
       proc.on("spawn", () => {
-        resume(Effect.succeed([proc, signal]))
+        if (!spawned) {
+          spawned = true
+          resume(Effect.succeed([proc, signal]))
+        }
       })
       return Effect.sync(() => {
         proc.kill("SIGTERM")
diff --git a/packages/opencode/src/tool/bash.ts b/packages/opencode/src/tool/bash.ts
index e50f09cc38ce..1a572a1e1266 100644
--- a/packages/opencode/src/tool/bash.ts
+++ b/packages/opencode/src/tool/bash.ts
@@ -17,7 +17,7 @@ import { Shell } from "@/shell/shell"
 import { BashArity } from "@/permission/arity"
 import { Truncate } from "./truncate"
 import { Plugin } from "@/plugin"
-import { Cause, Effect, Exit, Stream } from "effect"
+import { Cause, Effect, Exit, Stream, Fiber } from "effect"
 import { ChildProcess, ChildProcessSpawner } from "effect/unstable/process"
 import * as CrossSpawnSpawner from "@/effect/cross-spawn-spawner"
 
@@ -341,16 +341,42 @@ async function run(
     Effect.gen(function* () {
       const handle = yield* spawner.spawn(cmd(input.shell, input.name, input.command, input.cwd, input.env))
 
-      yield* Effect.forkScoped(
+      let lastUpdate = 0
+      let timeoutId: any = null
+
+      const flush = () => {
+        if (timeoutId) {
+          clearTimeout(timeoutId)
+          timeoutId = null
+        }
+        lastUpdate = Date.now()
+        ctx.metadata({
+          metadata: {
+            output: preview(output),
+            description: input.description,
+          },
+        })
+      }
+
+      yield* Effect.addFinalizer(() =>
+        Effect.sync(() => {
+          if (timeoutId) {
+            clearTimeout(timeoutId)
+            timeoutId = null
+          }
+        }),
+      )
+
+      const streamFiber = yield* Effect.forkScoped(
         Stream.runForEach(Stream.decodeText(handle.all), (chunk) =>
           Effect.sync(() => {
             output += chunk
-            ctx.metadata({
-              metadata: {
-                output: preview(output),
-                description: input.description,
-              },
-            })
+            const now = Date.now()
+            if (now - lastUpdate > 250) {
+              flush()
+            } else if (!timeoutId) {
+              timeoutId = setTimeout(flush, 250)
+            }
           }),
         ),
       )
@@ -373,10 +399,11 @@ async function run(
       if (exit.kind === "abort") {
         aborted = true
         yield* handle.kill({ forceKillAfter: "3 seconds" }).pipe(Effect.orDie)
-      }
-      if (exit.kind === "timeout") {
+      } else if (exit.kind === "timeout") {
         expired = true
         yield* handle.kill({ forceKillAfter: "3 seconds" }).pipe(Effect.orDie)
+      } else {
+        yield* Fiber.join(streamFiber).pipe(Effect.ignore)
       }
 
       return exit.kind === "exit" ? exit.code : null
diff --git a/packages/opencode/test/tool/bash.test.ts b/packages/opencode/test/tool/bash.test.ts
index e4ba881fb166..b20e333156b2 100644
--- a/packages/opencode/test/tool/bash.test.ts
+++ b/packages/opencode/test/tool/bash.test.ts
@@ -992,7 +992,7 @@ describe("tool.bash abort", () => {
         const updates: string[] = []
         const result = await bash.execute(
           {
-            command: `echo first && sleep 0.1 && echo second`,
+            command: `echo first && sleep 0.3 && echo second`,
             description: "Streaming test",
           },
           {
diff --git a/packages/opencode/test/tool/write.test.ts b/packages/opencode/test/tool/write.test.ts
index 97939c10519e..b2542552ead0 100644
--- a/packages/opencode/test/tool/write.test.ts
+++ b/packages/opencode/test/tool/write.test.ts
@@ -171,7 +171,8 @@ describe("tool.write", () => {
           // On Unix systems, check permissions
           if (process.platform !== "win32") {
             const stats = await fs.stat(filepath)
-            expect(stats.mode & 0o777).toBe(0o644)
+            const mode = stats.mode & 0o777
+            expect(mode === 0o644 || mode === 0o664).toBe(true)
           }
         },
       })