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 f287ea25c5c..890d69c28b4 100644
--- a/packages/opencode/src/cli/cmd/tui/component/prompt/index.tsx
+++ b/packages/opencode/src/cli/cmd/tui/component/prompt/index.tsx
@@ -526,12 +526,9 @@ export function Prompt(props: PromptProps) {
           const content = await Editor.open({
             value,
             renderer,
-            cwd:
-              (project.instance.path().worktree === "/" ? undefined : project.instance.path().worktree) ||
-              project.instance.directory() ||
-              process.cwd(),
+            cwd: project.instance.cwd(),
           })
-          if (!content) return
+          if (content === undefined) return
 
           input.setText(content)
 
diff --git a/packages/opencode/src/cli/cmd/tui/context/project.tsx b/packages/opencode/src/cli/cmd/tui/context/project.tsx
index 22dd94bc828..07892708a4f 100644
--- a/packages/opencode/src/cli/cmd/tui/context/project.tsx
+++ b/packages/opencode/src/cli/cmd/tui/context/project.tsx
@@ -79,6 +79,13 @@ export const { use: useProject, provider: ProjectProvider } = createSimpleContex
         directory() {
           return store.instance.path.directory
         },
+        cwd() {
+          return (
+            (store.instance.path.worktree === "/" ? undefined : store.instance.path.worktree) ||
+            store.instance.path.directory ||
+            process.cwd()
+          )
+        },
       },
       workspace: {
         current() {
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 d8dbd689f1e..5cbfb347279 100644
--- a/packages/opencode/src/cli/cmd/tui/routes/session/index.tsx
+++ b/packages/opencode/src/cli/cmd/tui/routes/session/index.tsx
@@ -972,13 +972,10 @@ export function Session() {
 
           if (options.openWithoutSaving) {
             // Just open in editor without saving
-            await Editor.open({
+            await Editor.openTemporary({
               value: transcript,
               renderer,
-              cwd:
-                (project.instance.path().worktree === "/" ? undefined : project.instance.path().worktree) ||
-                project.instance.directory() ||
-                process.cwd(),
+              cwd: project.instance.cwd(),
             })
           } else {
             const exportDir = process.cwd()
@@ -986,21 +983,21 @@ export function Session() {
             const filepath = path.join(exportDir, filename)
 
             await Filesystem.write(filepath, transcript)
-
-            // Open with EDITOR if available
-            const result = await Editor.open({
-              value: transcript,
+            const error = await Editor.openFile({
+              filepath,
               renderer,
-              cwd:
-                (project.instance.path().worktree === "/" ? undefined : project.instance.path().worktree) ||
-                project.instance.directory() ||
-                process.cwd(),
+              cwd: project.instance.cwd(),
+              directory: project.instance.directory() || process.cwd(),
             })
-            if (result !== undefined) {
-              await Filesystem.write(filepath, result)
-            }
+              .then(() => undefined)
+              .catch(errorMessage)
 
-            toast.show({ message: `Session exported to ${filename}`, variant: "success" })
+            toast.show({
+              message: error
+                ? `Session exported to ${filename}, but failed to open file: ${error}`
+                : `Session exported to ${filename}`,
+              variant: error ? "warning" : "success",
+            })
           }
         } catch {
           toast.show({ message: "Failed to export session", variant: "error" })
@@ -1744,6 +1741,20 @@ type ToolProps<T> = {
   output?: string
   part: ToolPart
 }
+
+function useOpenFile() {
+  const project = useProject()
+  const toast = useToast()
+  const renderer = useRenderer()
+  return (filePath: string | undefined) => {
+    if (!filePath) return
+    const cwd = project.instance.cwd()
+    void Editor.openFile({ filepath: filePath, renderer, cwd, directory: project.instance.directory() || cwd }).catch(
+      (error) => toast.show({ message: `Failed to open file: ${errorMessage(error)}`, variant: "error" }),
+    )
+  }
+}
+
 function GenericTool(props: ToolProps<any>) {
   const { theme } = useTheme()
   const ctx = use()
@@ -1962,6 +1973,7 @@ function BlockTool(props: {
   title: string
   children: JSX.Element
   onClick?: () => void
+  onTitleClick?: () => void
   part?: ToolPart
   spinner?: boolean
 }) {
@@ -1991,7 +2003,16 @@ function BlockTool(props: {
       <Show
         when={props.spinner}
         fallback={
-          <text paddingLeft={3} fg={theme.textMuted}>
+          <text
+            paddingLeft={3}
+            fg={hover() && props.onTitleClick ? theme.text : theme.textMuted}
+            onMouseOver={() => props.onTitleClick && setHover(true)}
+            onMouseOut={() => props.onTitleClick && setHover(false)}
+            onMouseUp={() => {
+              if (renderer.getSelection()?.getSelectedText()) return
+              props.onTitleClick?.()
+            }}
+          >
             {props.title}
           </text>
         }
@@ -2067,6 +2088,8 @@ function Shell(props: ToolProps<typeof ShellTool>) {
 function Write(props: ToolProps<typeof WriteTool>) {
   const { theme, syntax } = useTheme()
   const pathFormatter = usePathFormatter()
+  const openFile = useOpenFile()
+  const filePath = createMemo(() => props.metadata.filepath ?? props.input.filePath)
   const code = createMemo(() => {
     if (!props.input.content) return ""
     return props.input.content
@@ -2075,7 +2098,11 @@ function Write(props: ToolProps<typeof WriteTool>) {
   return (
     <Switch>
       <Match when={props.metadata.diagnostics !== undefined}>
-        <BlockTool title={"# Wrote " + pathFormatter.format(props.input.filePath)} part={props.part}>
+        <BlockTool
+          title={"# Wrote " + pathFormatter.format(props.input.filePath)}
+          part={props.part}
+          onTitleClick={props.part.state.status === "completed" ? () => openFile(filePath()) : undefined}
+        >
           <line_number fg={theme.textMuted} minWidth={3} paddingRight={1}>
             <code
               conceal={false}
@@ -2089,7 +2116,13 @@ function Write(props: ToolProps<typeof WriteTool>) {
         </BlockTool>
       </Match>
       <Match when={true}>
-        <InlineTool icon="←" pending="Preparing write..." complete={props.input.filePath} part={props.part}>
+        <InlineTool
+          icon="←"
+          pending="Preparing write..."
+          complete={props.input.filePath}
+          part={props.part}
+          onClick={props.part.state.status === "completed" ? () => openFile(filePath()) : undefined}
+        >
           Write {pathFormatter.format(props.input.filePath)}
         </InlineTool>
       </Match>
@@ -2287,6 +2320,8 @@ function Edit(props: ToolProps<typeof EditTool>) {
   const ctx = use()
   const { theme, syntax } = useTheme()
   const pathFormatter = usePathFormatter()
+  const openFile = useOpenFile()
+  const filePath = createMemo(() => props.metadata.filediff?.file ?? props.input.filePath)
 
   const view = createMemo(() => {
     const diffStyle = ctx.tui.diff_style
@@ -2302,7 +2337,11 @@ function Edit(props: ToolProps<typeof EditTool>) {
   return (
     <Switch>
       <Match when={props.metadata.diff !== undefined}>
-        <BlockTool title={"← Edit " + pathFormatter.format(props.input.filePath)} part={props.part}>
+        <BlockTool
+          title={"← Edit " + pathFormatter.format(props.input.filePath)}
+          part={props.part}
+          onTitleClick={props.part.state.status === "completed" ? () => openFile(filePath()) : undefined}
+        >
           <box paddingLeft={1}>
             <diff
               diff={diffContent()}
@@ -2328,7 +2367,13 @@ function Edit(props: ToolProps<typeof EditTool>) {
         </BlockTool>
       </Match>
       <Match when={true}>
-        <InlineTool icon="←" pending="Preparing edit..." complete={props.input.filePath} part={props.part}>
+        <InlineTool
+          icon="←"
+          pending="Preparing edit..."
+          complete={props.input.filePath}
+          part={props.part}
+          onClick={props.part.state.status === "completed" ? () => openFile(filePath()) : undefined}
+        >
           Edit {pathFormatter.format(props.input.filePath)} {input({ replaceAll: props.input.replaceAll })}
         </InlineTool>
       </Match>
@@ -2340,6 +2385,7 @@ function ApplyPatch(props: ToolProps<typeof ApplyPatchTool>) {
   const ctx = use()
   const { theme, syntax } = useTheme()
   const pathFormatter = usePathFormatter()
+  const openFile = useOpenFile()
 
   const files = createMemo(() => props.metadata.files ?? [])
 
@@ -2387,7 +2433,15 @@ function ApplyPatch(props: ToolProps<typeof ApplyPatchTool>) {
       <Match when={files().length > 0}>
         <For each={files()}>
           {(file) => (
-            <BlockTool title={title(file)} part={props.part}>
+            <BlockTool
+              title={title(file)}
+              part={props.part}
+              onTitleClick={
+                props.part.state.status !== "completed" || file.type === "delete"
+                  ? undefined
+                  : () => openFile(file.movePath ?? file.filePath)
+              }
+            >
               <Show
                 when={file.type !== "delete"}
                 fallback={
diff --git a/packages/opencode/src/cli/cmd/tui/util/editor.ts b/packages/opencode/src/cli/cmd/tui/util/editor.ts
index 03d91cf6dd1..4660aafb540 100644
--- a/packages/opencode/src/cli/cmd/tui/util/editor.ts
+++ b/packages/opencode/src/cli/cmd/tui/util/editor.ts
@@ -1,23 +1,69 @@
 import { defer } from "@/util/defer"
-import { rm } from "node:fs/promises"
+import { mkdtemp, rm } from "node:fs/promises"
 import { tmpdir } from "node:os"
 import { join } from "node:path"
-import { CliRenderer } from "@opentui/core"
+import type { CliRenderer } from "@opentui/core"
 import { Filesystem } from "@/util/filesystem"
 import { Process } from "@/util/process"
+import systemOpen from "open"
 
-export async function open(opts: { value: string; renderer: CliRenderer; cwd?: string }): Promise<string | undefined> {
-  const editor = process.env["VISUAL"] || process.env["EDITOR"]
+export async function open(opts: { value: string; renderer: CliRenderer; cwd: string }): Promise<string | undefined> {
+  const editor = configuredEditor()
   if (!editor) return
 
-  const filepath = join(tmpdir(), `${Date.now()}.md`)
-  await using _ = defer(async () => rm(filepath, { force: true }))
+  const draft = await createDraft(opts.value)
+  await using _ = defer(draft.remove)
+  await openEditor(draft.filepath, opts, editor)
+  return Filesystem.readText(draft.filepath)
+}
 
-  await Filesystem.write(filepath, opts.value)
+export async function openTemporary(opts: { value: string; renderer: CliRenderer; cwd: string }) {
+  const draft = await createDraft(opts.value)
+  const mode = await openPath(draft.filepath, opts).catch(async (error) => {
+    await draft.remove()
+    throw error
+  })
+  // System openers detach, so retain the draft in the OS temp dir for the application to read.
+  if (mode === "system") return
+  await draft.remove()
+}
+
+export async function openFile(opts: { filepath: string; renderer: CliRenderer; cwd: string; directory: string }) {
+  await openPath(Filesystem.resolveFilePath(opts.directory, opts.filepath), opts)
+}
+
+async function createDraft(value: string) {
+  const dir = await mkdtemp(join(tmpdir(), "opencode-editor-"))
+  const filepath = join(dir, "draft.md")
+  await Filesystem.write(filepath, value).catch(async (error) => {
+    await rm(dir, { force: true, recursive: true })
+    throw error
+  })
+  return {
+    filepath,
+    remove: () => rm(dir, { force: true, recursive: true }),
+  }
+}
+
+async function openPath(filepath: string, opts: { renderer: CliRenderer; cwd: string }) {
+  const editor = configuredEditor()
+  if (editor) {
+    await openEditor(filepath, opts, editor)
+    return "editor" as const
+  }
+  await systemOpen(filepath)
+  return "system" as const
+}
+
+function configuredEditor() {
+  return process.env["VISUAL"]?.trim() || process.env["EDITOR"]?.trim()
+}
+
+async function openEditor(filepath: string, opts: { renderer: CliRenderer; cwd: string }, editor: string) {
   opts.renderer.suspend()
   opts.renderer.currentRenderBuffer.clear()
   try {
-    const parts = editor.split(" ")
+    const parts = editor.split(/\s+/)
     const proc = Process.spawn([...parts, filepath], {
       cwd: opts.cwd,
       stdin: "inherit",
@@ -25,9 +71,8 @@ export async function open(opts: { value: string; renderer: CliRenderer; cwd?: s
       stderr: "inherit",
       shell: process.platform === "win32",
     })
-    await proc.exited
-    const content = await Filesystem.readText(filepath)
-    return content || undefined
+    const code = await proc.exited
+    if (code !== 0) throw new Error(`Editor exited with code ${code}`)
   } finally {
     opts.renderer.currentRenderBuffer.clear()
     opts.renderer.resume()
diff --git a/packages/opencode/test/cli/tui/editor.test.ts b/packages/opencode/test/cli/tui/editor.test.ts
new file mode 100644
index 00000000000..74c21454f5d
--- /dev/null
+++ b/packages/opencode/test/cli/tui/editor.test.ts
@@ -0,0 +1,180 @@
+import { afterEach, expect, mock, test } from "bun:test"
+import { rm } from "node:fs/promises"
+import { dirname, join } from "node:path"
+import type { CliRenderer } from "@opentui/core"
+import { errorMessage } from "../../../src/util/error"
+import { tmpdir } from "../../fixture/fixture"
+
+const originalVisual = process.env.VISUAL
+const originalEditor = process.env.EDITOR
+const systemOpened: string[] = []
+const retained = new Set<string>()
+
+void mock.module("open", () => ({
+  default: async (filepath: string) => {
+    systemOpened.push(filepath)
+  },
+}))
+
+const Editor = await import("../../../src/cli/cmd/tui/util/editor")
+
+afterEach(async () => {
+  if (originalVisual === undefined) delete process.env.VISUAL
+  else process.env.VISUAL = originalVisual
+  if (originalEditor === undefined) delete process.env.EDITOR
+  else process.env.EDITOR = originalEditor
+  systemOpened.length = 0
+  await Promise.all([...retained].map((dir) => rm(dir, { force: true, recursive: true })))
+  retained.clear()
+})
+
+function renderer() {
+  const events: string[] = []
+  return {
+    events,
+    value: {
+      suspend() {
+        events.push("suspend")
+      },
+      currentRenderBuffer: {
+        clear() {
+          events.push("clear")
+        },
+      },
+      resume() {
+        events.push("resume")
+      },
+      requestRender() {
+        events.push("render")
+      },
+    } as unknown as CliRenderer,
+  }
+}
+
+async function editor(dir: string, name: string, source: string) {
+  const filepath = join(dir, `${name}.ts`)
+  await Bun.write(filepath, source)
+  return `${process.execPath} ${filepath}`
+}
+
+test("open returns without suspending the renderer when no editor is configured", async () => {
+  delete process.env.VISUAL
+  delete process.env.EDITOR
+  const render = renderer()
+
+  expect(await Editor.open({ value: "secret", renderer: render.value, cwd: process.cwd() })).toBeUndefined()
+  expect(render.events).toEqual([])
+})
+
+test("openFile prefers VISUAL and separates file resolution from editor cwd", async () => {
+  await using directory = await tmpdir()
+  await using cwd = await tmpdir()
+  const target = join(directory.path, "target.md")
+  const marker = join(directory.path, "marker.txt")
+  await Bun.write(target, "target")
+  process.env.VISUAL = await editor(
+    directory.path,
+    "visual",
+    `await Bun.write(${JSON.stringify(marker)}, process.cwd() + "\\n" + process.argv.at(-1))`,
+  )
+  process.env.EDITOR = await editor(directory.path, "editor", "process.exit(7)")
+  const render = renderer()
+
+  await Editor.openFile({ filepath: "target.md", renderer: render.value, cwd: cwd.path, directory: directory.path })
+
+  expect(await Bun.file(marker).text()).toBe(`${cwd.path}\n${target}`)
+  expect(render.events).toEqual(["suspend", "clear", "clear", "resume", "render"])
+})
+
+test("openFile falls back to EDITOR when VISUAL is empty", async () => {
+  await using tmp = await tmpdir()
+  const target = join(tmp.path, "target.md")
+  const marker = join(tmp.path, "marker.txt")
+  await Bun.write(target, "target")
+  process.env.VISUAL = ""
+  process.env.EDITOR = await editor(
+    tmp.path,
+    "editor",
+    `await Bun.write(${JSON.stringify(marker)}, process.argv.at(-1)!)`,
+  )
+
+  await Editor.openFile({ filepath: target, renderer: renderer().value, cwd: tmp.path, directory: tmp.path })
+
+  expect(await Bun.file(marker).text()).toBe(target)
+})
+
+test("open returns empty edited content and removes its draft", async () => {
+  await using tmp = await tmpdir()
+  const marker = join(tmp.path, "marker.txt")
+  process.env.VISUAL = await editor(
+    tmp.path,
+    "editor",
+    `const filepath = process.argv.at(-1)!; await Bun.write(${JSON.stringify(marker)}, filepath); await Bun.write(filepath, "")`,
+  )
+
+  expect(await Editor.open({ value: "draft", renderer: renderer().value, cwd: tmp.path })).toBe("")
+  expect(await draftExists(marker)).toBeFalse()
+})
+
+test("openTemporary removes drafts after blocking editors exit", async () => {
+  await using tmp = await tmpdir()
+  const marker = join(tmp.path, "marker.txt")
+  process.env.VISUAL = await editor(
+    tmp.path,
+    "editor",
+    `await Bun.write(${JSON.stringify(marker)}, process.argv.at(-1)!)`,
+  )
+
+  await Editor.openTemporary({ value: "transcript", renderer: renderer().value, cwd: tmp.path })
+
+  expect(await draftExists(marker)).toBeFalse()
+})
+
+test("openTemporary retains drafts opened by the platform application", async () => {
+  delete process.env.VISUAL
+  delete process.env.EDITOR
+
+  await Editor.openTemporary({ value: "transcript", renderer: renderer().value, cwd: process.cwd() })
+
+  expect(systemOpened).toHaveLength(1)
+  const filepath = systemOpened[0]
+  expect(filepath).toBeDefined()
+  if (!filepath) return
+  retained.add(dirname(filepath))
+  expect(await Bun.file(filepath).text()).toBe("transcript")
+})
+
+test("openFile uses the platform application when no editor is configured", async () => {
+  await using tmp = await tmpdir()
+  delete process.env.VISUAL
+  delete process.env.EDITOR
+  const target = join(tmp.path, "target.md")
+  await Bun.write(target, "target")
+
+  await Editor.openFile({ filepath: "target.md", renderer: renderer().value, cwd: tmp.path, directory: tmp.path })
+
+  expect(systemOpened).toEqual([target])
+})
+
+test("openFile restores the renderer when the editor exits unsuccessfully", async () => {
+  await using tmp = await tmpdir()
+  process.env.VISUAL = await editor(tmp.path, "editor", "process.exit(7)")
+  const target = join(tmp.path, "target.md")
+  await Bun.write(target, "target")
+  const render = renderer()
+
+  const message = await Editor.openFile({
+    filepath: target,
+    renderer: render.value,
+    cwd: tmp.path,
+    directory: tmp.path,
+  })
+    .then(() => undefined)
+    .catch(errorMessage)
+  expect(message).toBe("Editor exited with code 7")
+  expect(render.events).toEqual(["suspend", "clear", "clear", "resume", "render"])
+})
+
+async function draftExists(marker: string) {
+  return Bun.file(await Bun.file(marker).text()).exists()
+}