diff --git a/.agents/notes/implemented/feature/2026-07-28-tool-call-file-open-in-os.i18n.yaml b/.agents/notes/implemented/feature/2026-07-28-tool-call-file-open-in-os.i18n.yaml
new file mode 100644
index 0000000000..44869d6f05
--- /dev/null
+++ b/.agents/notes/implemented/feature/2026-07-28-tool-call-file-open-in-os.i18n.yaml
@@ -0,0 +1,6 @@
+# Bilingual-pair consistency record (docs/i18n/README.md): the git blob hash of each
+# side as of the last confirmed-consistent state. Both languages carry equal authority;
+# after editing either side, bring the other along and re-record with:
+#   pnpm run verify-translation-pairing --write .agents/notes/implemented/feature/2026-07-28-tool-call-file-open-in-os.md
+2026-07-28-tool-call-file-open-in-os.md: a2c9b52507d32c2d851f811f0ecdd878a60b1e1c
+2026-07-28-tool-call-file-open-in-os.zh.md: efb4c39503d9de71a9d773bdae7fac4fb2b08ee3
diff --git a/.agents/notes/implemented/feature/2026-07-28-tool-call-file-open-in-os.md b/.agents/notes/implemented/feature/2026-07-28-tool-call-file-open-in-os.md
new file mode 100644
index 0000000000..a2c9b52507
--- /dev/null
+++ b/.agents/notes/implemented/feature/2026-07-28-tool-call-file-open-in-os.md
@@ -0,0 +1,30 @@
+# Agent Note: Tool-call file open in OS
+
+Status: implemented
+
+English | [中文](2026-07-28-tool-call-file-open-in-os.zh.md)
+
+## Problem
+
+Chat tool rows treated the whole summary line as a click target that opened the right-hand details panel, with a hover background on the row. For filesystem tools the useful action is opening the mentioned file in the operating system's default application, not inspecting the raw tool payload in a sidebar.
+
+## Decision
+
+File-tool path summaries (`read` / `write` / `edit` args carrying `path` or `file_path`) render as hover-underline links with a pointer cursor. Clicking the path calls `host.openPath` through `WorkspacesService.openPath`, resolving relative paths against the session cwd. File-link rows disable args expand (leading icon is inert); whole-row click, row hover fill, and the click-to-open-details gesture are removed from tool rows (including bash and todo registrations). The details panel and its inject surface remain for programmatic selection; rows no longer drive them.
+
+`host.openPath` is a privileged unary RPC accepted only from loopback, same-origin browser requests (same carrier guard as `host.pickDirectory`). Platform adapters open without a shell: `open` on macOS, PowerShell `Invoke-Item` on Windows, `xdg-open` on Linux. The opener is injectable for tests. URL-only read args (`web_fetch`) are not file links.
+
+## Alternatives considered
+
+- Keep row-click details and add a separate file affordance — rejected; the product ask replaces the row gesture with the file link.
+- Open files inside an in-app preview — rejected; the ask is the OS default application.
+- Reuse `host.pickDirectory`'s timeout exemption — unnecessary; path open hand-off completes quickly under the normal unary deadline.
+
+## Consequences
+
+Clicking a file path in a tool row opens that path on the host. Non-file tool rows are inert summaries (expand toggles remain where the row already supported them). Remote or non-loopback clients cannot invoke `host.openPath`.
+
+## Risks
+
+- Linux hosts without `xdg-open` fail the RPC; the chat row stays silent while the host returns an internal error.
+- Relative paths without a session cwd are forwarded verbatim and may fail on the host.
diff --git a/.agents/notes/implemented/feature/2026-07-28-tool-call-file-open-in-os.zh.md b/.agents/notes/implemented/feature/2026-07-28-tool-call-file-open-in-os.zh.md
new file mode 100644
index 0000000000..efb4c39503
--- /dev/null
+++ b/.agents/notes/implemented/feature/2026-07-28-tool-call-file-open-in-os.zh.md
@@ -0,0 +1,30 @@
+# Agent Note: 在工具调用中用系统应用打开文件
+
+Status: implemented
+
+[English](2026-07-28-tool-call-file-open-in-os.md) | 中文
+
+## Problem
+
+聊天工具行把整行摘要当作点击目标，点击后打开右侧 details 面板，并带有整行悬停背景。对文件系统工具而言，有用的动作是用操作系统默认应用打开所涉文件，而不是在侧栏里查看原始工具载荷。
+
+## Decision
+
+文件工具的路径摘要（`read`／`write`／`edit` 参数中的 `path` 或 `file_path`）渲染为悬停下划线链接并使用 pointer 光标。点击路径会经 `WorkspacesService.openPath` 调用 `host.openPath`，相对路径相对会话 cwd 解析。带文件链接的行关闭参数展开（左侧图标不可点）；工具行（含 bash 与 todo 注册）去掉整行点击、整行悬停底色，以及点击打开 details 的手势。details 面板及其 inject 面仍保留供程序化选择；工具行不再驱动它们。
+
+`host.openPath` 是特权一元 RPC，仅接受来自回环、同源浏览器请求（与 `host.pickDirectory` 相同的载体守卫）。平台适配器不经 shell 打开：macOS 为 `open`，Windows 为 PowerShell `Invoke-Item`，Linux 为 `xdg-open`。打开器可在测试中注入。仅含 URL 的 read 参数（`web_fetch`）不是文件链接。
+
+## Alternatives considered
+
+- 保留整行点击打开 details，另加文件入口 — 否决；产品要求用文件链接替换整行手势。
+- 在应用内预览文件 — 否决；要求是操作系统默认应用。
+- 复用 `host.pickDirectory` 的超时豁免 — 不必要；打开路径的交接在常规一元截止时间内即可完成。
+
+## Consequences
+
+点击工具行中的文件路径会在宿主上打开该路径。非文件工具行是惰性摘要（行内已有的展开开关仍保留）。远程或非回环客户端无法调用 `host.openPath`。
+
+## Risks
+
+- 没有 `xdg-open` 的 Linux 宿主会使 RPC 失败；聊天行保持静默，宿主返回 internal 错误。
+- 没有会话 cwd 时相对路径会原样转发，可能在宿主侧失败。
diff --git a/apps/web/tests/code-mode-fixture.snapshot.ts b/apps/web/tests/code-mode-fixture.snapshot.ts
index f53777fff8..ce5a98b2eb 100644
--- a/apps/web/tests/code-mode-fixture.snapshot.ts
+++ b/apps/web/tests/code-mode-fixture.snapshot.ts
@@ -5,7 +5,7 @@
 // the code-variant parent row titled by the model-authored description, its
 // three always-visible nested sub-rows (bash through the sample registration,
 // read through GenericToolCard, the failing read wearing the error state),
-// the expanded program body, details-panel resolution of a sub-callId, and
+// the expanded program body, inert bash / file-link sub-row gestures, and
 // the trajectory/waterfall tabs' sub-call cells and timing lanes.
 import { readFileSync } from 'node:fs'
 import { join } from 'node:path'
@@ -152,7 +152,7 @@ it('renders the fixture run_code turn: code parent row, nested sub-rows, error s
   `)
 })
 
-it('expands the code row into the program body and resolves a sub-row through the details panel', async () => {
+it('expands the code row into the program body; sub-row clicks do not open details', async () => {
   boot()
   await openFixtureSession()
 
@@ -171,26 +171,28 @@ it('expands the code row into the program body and resolves a sub-row through th
     }
   })
 
-  // Sub-row click → details panel resolves the sub-callId with FULL output.
+  // Tool rows no longer drive the details panel: bash is inert, file paths
+  // are host-open links (fixture openPath is a no-op success).
   const nest = document.querySelector('[data-subcalls]')
   if (nest === null) throw new Error('sub-call nest missing')
   const bashRow = nest.querySelector('[data-sample="bash-global"]')
   if (bashRow === null) throw new Error('bash sample sub-row missing')
+  const fileLink = nest.querySelector('button')
+  if (fileLink === null) throw new Error('file-path summary link missing on a read sub-row')
+  const frame = document.querySelector('[data-details-collapsed]')
+  if (frame === null) throw new Error('app frame missing')
+  expect(frame.getAttribute('data-details-collapsed')).toBe('true')
   fireEvent.click(bashRow)
-  const details = await screen.findByText('Input')
-  const panel = details.closest('[class*="root"]')
-  if (panel === null) throw new Error('details panel missing')
+  expect(frame.getAttribute('data-details-collapsed')).toBe('true')
+  fireEvent.click(fileLink)
+  expect(frame.getAttribute('data-details-collapsed')).toBe('true')
   expect({
-    title: visibleText(within(panel as HTMLElement).getByText('bash')),
-    inputEchoesArgs: visibleText(panel).includes('ls notes'),
-    outputComplete: visibleText(panel).includes('demo.txt new-demo.txt')
-      || visibleText(panel).includes('demo.txt\nnew-demo.txt')
-      || (panel.textContent ?? '').includes('demo.txt\nnew-demo.txt'),
+    fileLink: visibleText(fileLink),
+    detailsCollapsed: frame.getAttribute('data-details-collapsed'),
   }).toMatchInlineSnapshot(`
     {
-      "inputEchoesArgs": true,
-      "outputComplete": true,
-      "title": "bash",
+      "detailsCollapsed": "true",
+      "fileLink": "notes/demo.txt",
     }
   `)
 })
diff --git a/apps/web/tests/code-mode-round.e2e.ts b/apps/web/tests/code-mode-round.e2e.ts
index 32c51a2a2a..a7f493e448 100644
--- a/apps/web/tests/code-mode-round.e2e.ts
+++ b/apps/web/tests/code-mode-round.e2e.ts
@@ -118,19 +118,14 @@ describe('web e2e: Code Mode round renders nested sub-calls', () => {
     expect(await nest.locator('[data-state="error"]').count()).toBeGreaterThanOrEqual(1)
   }, 60_000)
 
-  it.skipIf(MODE === 'record')('a sub-row click opens the details panel on the sub-call material', async () => {
+  it.skipIf(MODE === 'record')('a bash sub-row click leaves the details panel collapsed', async () => {
     onTestFailed(() => saveFailureShot(page, 'web-e2e-code-mode-details'))
     const nest = page.locator('[data-subcalls]').first()
+    const frame = page.locator('[data-details-collapsed], [class*="frame"]').first()
+    expect(await frame.getAttribute('data-details-collapsed')).not.toBeNull()
     await nest.locator('[data-sample="bash-global"]').first().click()
-    // The details column opens (width > 0) and shows the sub-call's complete
-    // output — the full-content log contract, no truncation marker anywhere.
-    await page.waitForFunction(() => {
-      const frame = document.querySelector('[class*="frame"]')
-      if (frame === null) return false
-      return Number(getComputedStyle(frame).gridTemplateColumns.split(' ').pop()!.replace('px', '')) > 0
-    }, undefined, { timeout: 10_000 })
-    await expect.poll(() => page.getByText('CODE_ROUND_OK', { exact: false }).count(), { timeout: 5_000 })
-      .toBeGreaterThanOrEqual(1)
+    // Tool rows no longer open details; the column stays width 0.
+    await expect.poll(() => frame.getAttribute('data-details-collapsed'), { timeout: 5_000 }).not.toBeNull()
   })
 
   it.skipIf(MODE === 'record')('matches the conversation aria golden with stable anchors', async () => {
diff --git a/apps/web/tests/navigation-panes.e2e.ts b/apps/web/tests/navigation-panes.e2e.ts
index bbae7363df..a27a61f80f 100644
--- a/apps/web/tests/navigation-panes.e2e.ts
+++ b/apps/web/tests/navigation-panes.e2e.ts
@@ -1,12 +1,11 @@
 // Web e2e scenarios: navigation & panes — the view tabs (Trajectory /
-// Waterfall), the details column, and sidebar search, all over ONE rich
-// two-turn seeded fixture rendered purely from the log (the seeded-history
-// pattern: zero model calls in replay, so every surface here is the client
-// fold + host history RPC, not replay binding). The seed is recorded live
-// under the standard discipline: turn 1 produces a bash call plus two
-// parallel reads in one assistant message (tool-call density for the
-// trajectory/waterfall lanes and a details-capable bash row), turn 2 a
-// markdown-rich reply (a second turn so the waterfall has two lanes).
+// Waterfall) and sidebar search, all over ONE rich two-turn seeded fixture
+// rendered purely from the log (the seeded-history pattern: zero model calls
+// in replay, so every surface here is the client fold + host history RPC,
+// not replay binding). The seed is recorded live under the standard
+// discipline: turn 1 produces a bash call plus two parallel reads in one
+// assistant message (tool-call density for the trajectory/waterfall lanes),
+// turn 2 a markdown-rich reply (a second turn so the waterfall has two lanes).
 import { mkdir, readFile, writeFile } from 'node:fs/promises'
 import { fileURLToPath } from 'node:url'
 import { join } from 'node:path'
@@ -25,7 +24,6 @@ const SNAPSHOT_DIR = fileURLToPath(new URL('./snapshots/navigation-panes', impor
 const SEED = join(SNAPSHOT_DIR, 'seed.jsonl')
 const TRAJECTORY_EXPECTED = join(SNAPSHOT_DIR, 'trajectory.expected.md')
 const WATERFALL_EXPECTED = join(SNAPSHOT_DIR, 'waterfall.expected.md')
-const DETAILS_EXPECTED = join(SNAPSHOT_DIR, 'details-open.expected.md')
 const MODE = webSnapshotMode()
 const SEED_ID = 'navigation-panes-web-e2e'
 
@@ -155,36 +153,27 @@ describe('web e2e: navigation & panes over a rich seeded session', () => {
     await compareOrRefreshGolden(WATERFALL_EXPECTED, snapshot, MODE)
   }, 60_000)
 
-  it.skipIf(MODE === 'record')('opens the details column from the bash row and closes it', async () => {
+  it.skipIf(MODE === 'record')('bash and file-path rows leave the details column collapsed', async () => {
     onTestFailed(() => saveFailureShot(page, 'web-e2e-navigation-details'))
     await page.getByRole('tab', { name: 'Chat' }).click()
-    // The bash toolview row routes its click to openDetails (read rows are
-    // expand-in-place instead — the seeded-history scenario owns that fold).
     const bashRow = page.locator('[data-sample="bash-global"]').first()
     await bashRow.waitFor({ timeout: 15_000 })
-    // Open/closed is the frame's collapsed attribute: the column collapses to
-    // width 0 but its subtree deliberately never unmounts (hidden, not
-    // absent), so element presence/visibility cannot express the state.
     const frame = page.locator('[data-details-collapsed], [class*="frame"]').first()
     expect(await frame.getAttribute('data-details-collapsed')).not.toBeNull()
     await bashRow.click()
-    await expect.poll(() => frame.getAttribute('data-details-collapsed'), { timeout: 10_000 }).toBeNull()
-    // The open panel shows the selected call's name, arguments, and durable
-    // result (NAVIGATION_OK appears in the chat row too, hence >= 2 total).
-    await expect.poll(() => page.getByText('NAVIGATION_OK', { exact: false }).count(), { timeout: 10_000 }).toBeGreaterThanOrEqual(2)
-    // Golden of the open panel: tool name header, Input args, Output result.
-    const snapshot = (await captureStableAria(page, '[class*="detailsCol"]', scaffold.workspaceCwd))
-      .split(SEED_ID).join('{{seededId}}')
-    await compareOrRefreshGolden(DETAILS_EXPECTED, snapshot, MODE)
-    await page.getByRole('button', { name: '关闭详情' }).click()
-    await expect.poll(() => frame.getAttribute('data-details-collapsed'), { timeout: 10_000 }).not.toBeNull()
+    await expect.poll(() => frame.getAttribute('data-details-collapsed'), { timeout: 5_000 }).not.toBeNull()
+    // Read summaries are host-open file links; they also must not open details.
+    const fileLink = page.locator('[data-variant="read"] button').first()
+    await fileLink.waitFor({ timeout: 10_000 })
+    await fileLink.click()
+    await expect.poll(() => frame.getAttribute('data-details-collapsed'), { timeout: 5_000 }).not.toBeNull()
   }, 60_000)
 
   it.skipIf(MODE === 'record')('issued zero model calls and stayed clean', async () => {
     expect(tripwire.pageErrors).toEqual([])
     expect(tripwire.warnings).toEqual([])
     await assertFixtureInventory(SNAPSHOT_DIR, [
-      'seed.jsonl', 'trajectory.expected.md', 'waterfall.expected.md', 'details-open.expected.md',
+      'seed.jsonl', 'trajectory.expected.md', 'waterfall.expected.md',
     ])
   })
 })
diff --git a/apps/web/tests/seeded-history.e2e.ts b/apps/web/tests/seeded-history.e2e.ts
index cd91ace3d3..d30b3d7c39 100644
--- a/apps/web/tests/seeded-history.e2e.ts
+++ b/apps/web/tests/seeded-history.e2e.ts
@@ -132,21 +132,19 @@ describe('web e2e: seeded history renders through cold resume', () => {
     await compareOrRefreshGolden(UI_EXPECTED, snapshot, MODE)
   })
 
-  it.skipIf(MODE === 'record')('expands and collapses a tool row rebuilt from the cold log', async () => {
+  it.skipIf(MODE === 'record')('file-path tool rows rebuilt from the cold log stay details-inert', async () => {
     onTestFailed(() => saveFailureShot(page, 'web-e2e-seeded-toolrow'))
-    // Interaction over cold-resumed history: read rows are expand-in-place
-    // rows (rowExpands routes the click to toggleExpand, not openDetails), so
-    // the gesture under test is the inline fold over log-rebuilt content.
-    // Runs after the golden capture; still zero model calls.
-    const row = page.locator('[data-variant] [data-clickable][role="button"]').first()
-    await row.waitFor({ timeout: 10_000 })
-    expect(await row.getAttribute('aria-expanded')).toBe('false')
-    await row.click()
-    await expect.poll(() => row.getAttribute('aria-expanded'), { timeout: 5_000 }).toBe('true')
-    // The expanded body renders the recorded tool result (a.txt's contents).
-    await expect.poll(() => page.getByText('alpha', { exact: false }).count(), { timeout: 5_000 }).toBeGreaterThan(0)
-    await row.click()
-    await expect.poll(() => row.getAttribute('aria-expanded'), { timeout: 5_000 }).toBe('false')
+    // Interaction over cold-resumed history: read summaries are host-open
+    // file links (not expand-in-place / not details). Runs after the golden
+    // capture; still zero model calls.
+    const fileLink = page.locator('[data-variant="read"] button').first()
+    await fileLink.waitFor({ timeout: 10_000 })
+    const frame = page.locator('[data-details-collapsed], [class*="frame"]').first()
+    expect(await frame.getAttribute('data-details-collapsed')).not.toBeNull()
+    await fileLink.click()
+    await expect.poll(() => frame.getAttribute('data-details-collapsed'), { timeout: 5_000 }).not.toBeNull()
+    // Path label survives from the recorded args (a.txt).
+    await expect.poll(() => page.getByText('a.txt', { exact: false }).count(), { timeout: 5_000 }).toBeGreaterThan(0)
   })
 
   it.skipIf(MODE === 'record')('issued zero model calls and stayed clean', async () => {
diff --git a/apps/web/tests/smoke-real.e2e.ts b/apps/web/tests/smoke-real.e2e.ts
index 58db1beafd..47d6ea81f7 100644
--- a/apps/web/tests/smoke-real.e2e.ts
+++ b/apps/web/tests/smoke-real.e2e.ts
@@ -7,7 +7,7 @@
 //
 // Selector convention: CSS Modules hash as [hash]_[local], so class-substring
 // selectors are unreliable — anchor on data-* attributes (data-variant /
-// data-clickable / data-sample) or visible text. The one [class*=] use below
+// data-sample) or visible text. The one [class*=] use below
 // (frame/handle) rides local names that survive hashing as suffixes; prefer
 // data-* for anything new.
 //
@@ -448,7 +448,7 @@ describe.skipIf(!process.env.DEEPSEEK_API_KEY || notReady.length > 0)('web smoke
     await screen(page, '07-back-to-chat')
   })
 
-  it('5 bash differential rendering: tool row click opens the details column', async () => {
+  it('5 bash differential rendering: tool row click leaves the details column collapsed', async () => {
     onTestFailed(() => saveFailureShot(page, 'w5-tool-details'))
     const input = page.locator('textarea').first()
     await input.fill('请用 bash 工具运行命令 echo w5marker 然后告诉我结果')
@@ -462,13 +462,9 @@ describe.skipIf(!process.env.DEEPSEEK_API_KEY || notReady.length > 0)('web smoke
     await screen(page, '08-bash-round')
     expect(await detailsTrack(page)).toBe(0)
     await toolRow.click()
-    // Selection channel: click writes selection + layout.openDetails.
-    await page.waitForFunction(() => {
-      const frame = document.querySelector('[class*="frame"]')
-      if (frame === null) return false
-      return Number(getComputedStyle(frame).gridTemplateColumns.split(' ').pop()!.replace('px', '')) > 0
-    }, undefined, { timeout: 10_000 })
-    await screen(page, '09-details-open')
+    // Tool rows no longer drive layout.openDetails; the column stays closed.
+    expect(await detailsTrack(page)).toBe(0)
+    await screen(page, '09-details-closed')
   }, 150_000)
 
   it('6 sidebar drag widens the column and persists across reload', async () => {
diff --git a/apps/web/tests/snapshots/navigation-panes/details-open.expected.md b/apps/web/tests/snapshots/navigation-panes/details-open.expected.md
deleted file mode 100644
index d69a95eb2d..0000000000
--- a/apps/web/tests/snapshots/navigation-panes/details-open.expected.md
+++ /dev/null
@@ -1,5 +0,0 @@
-- text: bash
-- button "关闭详情"
-- text: Input
-- code: "{ \"command\": \"echo NAVIGATION_OK\", \"description\": \"Print NAVIGATION_OK\" }"
-- text: Output NAVIGATION_OK
diff --git a/packages/client/connection/src/client/fixture.ts b/packages/client/connection/src/client/fixture.ts
index bdd43de968..6aa932b576 100644
--- a/packages/client/connection/src/client/fixture.ts
+++ b/packages/client/connection/src/client/fixture.ts
@@ -790,6 +790,7 @@ export function createFixtureApi(options: FixtureOptions = {}): ApiProxy {
     host: {
       describe: request => ok(request, { version: '0.0.0-fixture', cwd: '/tmp/fixture', attachedSessions }),
       pickDirectory: request => ok(request, { path: null }),
+      openPath: request => ok(request, { opened: true as const }),
     },
     workspace: {
       list: request => ok(request, { items: workspaces.map(w => ({ ...w })) }),
@@ -1049,6 +1050,7 @@ export class FixtureApiClient extends AbstractApiClient {
       case 'session.cancel': return this.api.sessions.cancel(request)
       case 'host.describe': return this.api.host.describe(request)
       case 'host.pickDirectory': return this.api.host.pickDirectory(request, new AbortController().signal)
+      case 'host.openPath': return this.api.host.openPath(request, new AbortController().signal)
       case 'workspace.list': return this.api.workspace.list(request)
       case 'workspace.create': return this.api.workspace.create(request)
       case 'workspace.rename': return this.api.workspace.rename(request)
diff --git a/packages/client/connection/src/index.ts b/packages/client/connection/src/index.ts
index bc73e0e054..33f6d0cc41 100644
--- a/packages/client/connection/src/index.ts
+++ b/packages/client/connection/src/index.ts
@@ -26,7 +26,8 @@ export function apply(ctx: Context): void {
     path: API_PATH,
     handler: async (req, res) => {
       const pathname = new URL(req.url ?? '/', 'http://dsh.internal').pathname
-      if (pathname === `${API_PATH}/host.pickDirectory`
+      if ((pathname === `${API_PATH}/host.pickDirectory`
+        || pathname === `${API_PATH}/host.openPath`)
         && !isTrustedNativeDialogRequest(req)) {
         res.writeHead(403)
         res.end('forbidden')
diff --git a/packages/client/connection/src/native-dialog-request.ts b/packages/client/connection/src/native-dialog-request.ts
index fe91bbae2d..0eaf09f149 100644
--- a/packages/client/connection/src/native-dialog-request.ts
+++ b/packages/client/connection/src/native-dialog-request.ts
@@ -1,4 +1,4 @@
-/** Trust check for browser requests that can open an operating-system dialog. */
+/** Trust check for browser requests that can invoke privileged native host actions. */
 
 import type { IncomingHttpHeaders } from 'node:http'
 
diff --git a/packages/client/connection/tests/fake-api.ts b/packages/client/connection/tests/fake-api.ts
index 4f4ef25445..1dac997ae2 100644
--- a/packages/client/connection/tests/fake-api.ts
+++ b/packages/client/connection/tests/fake-api.ts
@@ -67,6 +67,8 @@ export class FakeApiClient implements IApiClient {
     () => Promise.resolve(ok({ version: '0-fake', cwd: '/f', attachedSessions: 0 }))
   onPickDirectory: (payload: unknown) => Promise<RpcResponse<{ path: string | null }>> =
     () => Promise.resolve(ok({ path: null }))
+  onOpenPath: (payload: unknown) => Promise<RpcResponse<{ opened: true }>> =
+    () => Promise.resolve(ok({ opened: true as const }))
 
   private readonly muxConns: StreamConn<MuxFrame>[] = []
   private readonly hostConns: StreamConn<HostFrame>[] = []
@@ -89,6 +91,7 @@ export class FakeApiClient implements IApiClient {
   readonly host: IApiClient['host'] = {
     describe: payload => this.record('host.describe', payload, this.onDescribe(payload)),
     pickDirectory: payload => this.record('host.pickDirectory', payload, this.onPickDirectory(payload)),
+    openPath: payload => this.record('host.openPath', payload, this.onOpenPath(payload)),
   }
 
   readonly workspace: IApiClient['workspace'] = {
diff --git a/packages/client/connection/tests/node-half.spec.ts b/packages/client/connection/tests/node-half.spec.ts
index 86af61ba0d..2c90cd8b7a 100644
--- a/packages/client/connection/tests/node-half.spec.ts
+++ b/packages/client/connection/tests/node-half.spec.ts
@@ -28,22 +28,24 @@ describe('connection node half', () => {
     expect(routes).toHaveLength(1)
     expect(routes[0]).toMatchObject({ kind: 'prefix', path: API_PATH })
 
-    let status: number | undefined
-    let body: unknown
-    const deniedRequest = {
-      url: '/api/host.pickDirectory',
-      headers: {
-        host: 'harness.example', origin: 'http://harness.example', 'sec-fetch-site': 'same-origin',
-      },
-      socket: { remoteAddress: '192.168.1.8' },
-    } as unknown as IncomingMessage
-    const deniedResponse = {
-      writeHead(value: number) { status = value; return this },
-      end(value?: unknown) { body = value; return this },
-    } as unknown as ServerResponse
-    await routes[0]!.handler(deniedRequest, deniedResponse)
-    expect(status).toBe(403)
-    expect(body).toBe('forbidden')
+    for (const url of ['/api/host.pickDirectory', '/api/host.openPath']) {
+      let status: number | undefined
+      let body: unknown
+      const deniedRequest = {
+        url,
+        headers: {
+          host: 'harness.example', origin: 'http://harness.example', 'sec-fetch-site': 'same-origin',
+        },
+        socket: { remoteAddress: '192.168.1.8' },
+      } as unknown as IncomingMessage
+      const deniedResponse = {
+        writeHead(value: number) { status = value; return this },
+        end(value?: unknown) { body = value; return this },
+      } as unknown as ServerResponse
+      await routes[0]!.handler(deniedRequest, deniedResponse)
+      expect(status).toBe(403)
+      expect(body).toBe('forbidden')
+    }
 
     await fiber.dispose()
     expect(routes).toHaveLength(0)
diff --git a/packages/client/runtime/src/client/workspaces/service.ts b/packages/client/runtime/src/client/workspaces/service.ts
index fe345801c6..97f01d0bf1 100644
--- a/packages/client/runtime/src/client/workspaces/service.ts
+++ b/packages/client/runtime/src/client/workspaces/service.ts
@@ -182,6 +182,17 @@ export class WorkspacesService {
     return response.result.value.path
   }
 
+  /**
+   * Open a filesystem path with the Host operating system's default application.
+   * @param path - absolute or host-resolvable path.
+   */
+  async openPath(path: string): Promise<void> {
+    const response = await this.api.host.openPath({ path })
+    if (!response.result.ok) {
+      throw new Error(`path open failed: ${response.result.error.message}`)
+    }
+  }
+
   /**
    * Rename a Workspace.
    * @param workspaceId - target workspace.
diff --git a/packages/client/runtime/tests/fake-api.ts b/packages/client/runtime/tests/fake-api.ts
index bc30b8633f..b18ae87d8e 100644
--- a/packages/client/runtime/tests/fake-api.ts
+++ b/packages/client/runtime/tests/fake-api.ts
@@ -85,6 +85,8 @@ export class FakeApiClient implements IApiClient {
     () => Promise.resolve(ok({ version: '0-fake', cwd: '/f', attachedSessions: 0 }))
   onPickDirectory: (payload: unknown) => Promise<RpcResponse<{ path: string | null }>> =
     () => Promise.resolve(ok({ path: null }))
+  onOpenPath: (payload: unknown) => Promise<RpcResponse<{ opened: true }>> =
+    () => Promise.resolve(ok({ opened: true as const }))
 
   private readonly muxConns: StreamConn<MuxFrame>[] = []
   private readonly hostConns: StreamConn<HostFrame>[] = []
@@ -107,6 +109,7 @@ export class FakeApiClient implements IApiClient {
   readonly host: IApiClient['host'] = {
     describe: (payload: unknown) => this.record('host.describe', payload, this.onDescribe(payload)),
     pickDirectory: (payload: unknown) => this.record('host.pickDirectory', payload, this.onPickDirectory(payload)),
+    openPath: (payload: unknown) => this.record('host.openPath', payload, this.onOpenPath(payload)),
   }
 
   onWorkspaceList: (payload: unknown) => Promise<RpcResponse<{ items: never[] }>> = () => Promise.resolve(ok({ items: [] }))
diff --git a/packages/client/runtime/tests/workspaces-service.spec.ts b/packages/client/runtime/tests/workspaces-service.spec.ts
index 5327066651..6768fddff7 100644
--- a/packages/client/runtime/tests/workspaces-service.spec.ts
+++ b/packages/client/runtime/tests/workspaces-service.spec.ts
@@ -236,6 +236,17 @@ describe('WorkspacesService', () => {
     expect(api.callsOf('host.pickDirectory')).toEqual([{}, {}])
   })
 
+  it('opens a filesystem path through the host without local state', async () => {
+    const ctx = new Context()
+    const api = new FakeApiClient()
+    const sessions = new SessionsService(ctx, api)
+    const workspaces = new WorkspacesService(ctx, api, sessions)
+    await expect(workspaces.openPath('/w/alpha/a.ts')).resolves.toBeUndefined()
+    expect(api.callsOf('host.openPath')).toEqual([{ path: '/w/alpha/a.ts' }])
+    api.onOpenPath = () => Promise.resolve(err({ code: 'internal', message: 'boom', details: {} }))
+    await expect(workspaces.openPath('/missing')).rejects.toThrow(/path open failed/)
+  })
+
   it('deletes a Workspace or preserves it when the Host rejects deletion', async () => {
     const ctx = new Context()
     const api = new FakeApiClient()
diff --git a/packages/client/ui-conversation/README.i18n.yaml b/packages/client/ui-conversation/README.i18n.yaml
index c1a6828d5b..b685a6d9fe 100644
--- a/packages/client/ui-conversation/README.i18n.yaml
+++ b/packages/client/ui-conversation/README.i18n.yaml
@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/client/ui-conversation/README.md
-README.md: 56a445ccfa86e0b11cf5aefc37819a30746f0739
-README.zh.md: a7c160ecdd74074257c9d149630663dacd05c070
+README.md: a04c20f225c731581accbe8c12c52a5e7597029a
+README.zh.md: f9e6a635ea6090c87a66f029785af214025b9bda
diff --git a/packages/client/ui-conversation/README.md b/packages/client/ui-conversation/README.md
index 56a445ccfa..a04c20f225 100644
--- a/packages/client/ui-conversation/README.md
+++ b/packages/client/ui-conversation/README.md
@@ -8,9 +8,9 @@ The resident conversation shell survives no-session and session transitions. Wit
 
 The view ring IS a slot: the conversation registration declares the `'conversation.view'` list slot (session scope) in its `children` table, ConversationRoot renders the active entry through its renderSlot share (`only: <active id>`), and view tabs project from the ring ledger's registration options (`id`/`order`/`label`). The chat view is this package's own ring entry; other plugins (ui-trajectory) contribute tabs through plain `ctx.slots.register` — the former package-local view registry (`registerView`/`ViewEntry`/`ConversationViewMap` and the chrome attachment table) is retired, with per-view chrome dissolved into the view components themselves.
 
-Generic tool rows classify the built-in bash, read, search, write, edit, and run_code names into dedicated visual variants. The filesystem variants render the edit icon and `Write · <path>` or `Edit · <path>` summary while retaining the shared row-to-details interaction. The code variant summarizes with the model-authored `description` and expands to the program itself; its logged sub-dispatches render as always-visible nested rows through the SAME keyed toolview hole (custom registrations and the GenericToolCard fallback apply to sub-rows unchanged), and the details panel resolves a selected sub-call id to its full logged args and complete output. Cordis lifecycle tools reuse those generic variants while presenting `Inspect`, `Mount temporary Plugin`, and `Unmount temporary Plugin` with a shared Cordis accent; mount keeps the code variant's expandable source rendering.
+Generic tool rows classify the built-in bash, read, search, write, edit, and run_code names into dedicated visual variants. The filesystem variants render the edit icon and a path summary; that path is a hover-underline link that opens the file with the host OS default application (`host.openPath`, relative paths resolve against the session cwd). Tool rows are not whole-row click targets and do not open the details panel. The code variant summarizes with the model-authored `description` and expands to the program itself; its logged sub-dispatches render as always-visible nested rows through the SAME keyed toolview hole (custom registrations and the GenericToolCard fallback apply to sub-rows unchanged). Cordis lifecycle tools reuse those generic variants while presenting `Inspect`, `Mount temporary Plugin`, and `Unmount temporary Plugin` with a shared Cordis accent; mount keeps the code variant's expandable source rendering.
 
-Tool rows are slots too — the standalone tool ring (`ToolViewRegistry`/`ctx.toolviews`/outlet) is retired. The chat entry declares the keyed `'conversation.chat.toolview'` hole (session scope; the key space is runtime-open); its render site dispatches per row via `entryKey: toolName` with `GenericToolCard` as the call-site `fallback`. The owner payload is the uniform `ToolRowOwnerProps` (`callId`/`toolName`/`block`/`openDetails`) and `ToolRowProps` pre-composes it with the session standard kit. A registrant is a plain plugin: `ctx.slots.register({ name: 'conversation.chat.toolview', key: '<tool>', inject? }, Row)` with `inject: ['slots', 'conversation']` as the load-order seam (apply mounts ConversationService after the chat registration, so the service being present guarantees the slot is declared); session differentiation happens inside the component (`useSessions` reading `parentId` — the bash sample is the third-party-posture exemplar). Trajectory/waterfall toolview slots share this shape and land with their own render sites (RendersCheck rejects a declaration nobody renders).
+Tool rows are slots too — the standalone tool ring (`ToolViewRegistry`/`ctx.toolviews`/outlet) is retired. The chat entry declares the keyed `'conversation.chat.toolview'` hole (session scope; the key space is runtime-open); its render site dispatches per row via `entryKey: toolName` with `GenericToolCard` as the call-site `fallback`. The owner payload is the uniform `ToolRowOwnerProps` (`callId`/`toolName`/`block`/`openFile`) and `ToolRowProps` pre-composes it with the session standard kit. A registrant is a plain plugin: `ctx.slots.register({ name: 'conversation.chat.toolview', key: '<tool>', inject? }, Row)` with `inject: ['slots', 'conversation']` as the load-order seam (apply mounts ConversationService after the chat registration, so the service being present guarantees the slot is declared); session differentiation happens inside the component (`useSessions` reading `parentId` — the bash sample is the third-party-posture exemplar). Trajectory/waterfall toolview slots share this shape and land with their own render sites (RendersCheck rejects a declaration nobody renders).
 
 The todo surfaces are two registrations over that shape, both plain registrant plugins with `inject: ['slots', 'conversation']`. `TodoRow` takes the `'conversation.chat.toolview'` key `todo_write` and summarizes what the call attempted (`<done>/<total> 已完成 · <active item>` parsed from its args, falling back to the generic summary on malformed or wrongly-shaped model JSON, and keeping the generic dot for non-ok execution states so a cancelled call never reads as a completed update). `TodoDock` takes the `'conversation.input.dock'` list slot at `order: -1` — above the queue rows — and is the durable plan strip: it selects `todos` off the session snapshot and renders `TodoPanel`, which takes the plain list, hides itself while the list is empty, and collapses to a header of title plus `"<done>/<total> tasks · <n> in progress"` (status glyphs are the figma check / progress / dashed-pending set). The dock adapter owns the selection so the panel stays a pure function of its props; the persistent list lives here rather than in the row so the row stays one line. Anything the input-zone composer chain hides (a `conversation.composer` takeover such as ui-question's) hides the whole dock, this strip included.
 
diff --git a/packages/client/ui-conversation/README.zh.md b/packages/client/ui-conversation/README.zh.md
index a7c160ecdd..f9e6a635ea 100644
--- a/packages/client/ui-conversation/README.zh.md
+++ b/packages/client/ui-conversation/README.zh.md
@@ -8,9 +8,9 @@
 
 视图环本身就是 slot：会话注册声明 `'conversation.view'` 列表 slot（Session scope），并将其列在 `children` 表中；ConversationRoot 通过 renderSlot share 渲染活跃配置项（`only: <active id>`）；视图标签页从环账本的注册选项（`id`／`order`／`label`）投影而来。聊天视图是该包自身的环配置项；其他插件（ui-trajectory）通过普通的 `ctx.slots.register` 贡献标签页。先前包内的视图注册表（`registerView`／`ViewEntry`／`ConversationViewMap` 及 chrome 附加表）已退役，逐视图 chrome 则被拆入视图组件自身。
 
-通用工具行把内置的 bash、read、search、write、edit 和 run_code 名称归入专用视觉变体。文件系统变体会渲染 edit 图标和 `Write · <path>` 或 `Edit · <path>` 摘要，同时保留共享的行到详情交互。code 变体以模型撰写的 `description` 作摘要，展开后显示程序本身；其已记录的子调用经由同一个键控 toolview 空位渲染为始终可见的嵌套行（自定义注册和 GenericToolCard fallback 原样适用于子行），details 面板则会根据选中的子调用 id 解析出其完整记录的参数与完整输出。Cordis 生命周期工具复用这些通用变体，同时以统一的 Cordis 强调色呈现 `Inspect`、`Mount temporary Plugin` 和 `Unmount temporary Plugin`；mount 行保留 code 变体的可展开源码渲染。
+通用工具行把内置的 bash、read、search、write、edit 和 run_code 名称归入专用视觉变体。文件系统变体会渲染 edit 图标和路径摘要；该路径是悬停下划线链接，点击后通过宿主操作系统的默认应用打开文件（`host.openPath`，相对路径相对会话 cwd 解析）。工具行不再是整行点击目标，也不会打开 details 面板。code 变体以模型撰写的 `description` 作摘要，展开后显示程序本身；其已记录的子调用经由同一个键控 toolview 空位渲染为始终可见的嵌套行（自定义注册和 GenericToolCard fallback 原样适用于子行）。Cordis 生命周期工具复用这些通用变体，同时以统一的 Cordis 强调色呈现 `Inspect`、`Mount temporary Plugin` 和 `Unmount temporary Plugin`；mount 行保留 code 变体的可展开源码渲染。
 
-工具行同样是 slot：独立工具环（`ToolViewRegistry`／`ctx.toolviews`／outlet）已经退役。聊天配置项声明键控的 `'conversation.chat.toolview'` 空位（Session scope；key 空间在运行时开放）；其渲染点逐行通过 `entryKey: toolName` 分发，并以 `GenericToolCard` 作为调用点 `fallback`。owner 载荷是统一的 `ToolRowOwnerProps`（`callId`／`toolName`／`block`／`openDetails`），`ToolRowProps` 则预先将其与 Session 标准工具包组合。注册方只是普通插件：`ctx.slots.register({ name: 'conversation.chat.toolview', key: '<tool>', inject? }, Row)`，以 `inject: ['slots', 'conversation']` 作为加载顺序 seam（apply 在聊天注册后挂载 ConversationService，因此服务存在即可保证 slot 已声明）；Session 区分在组件内部完成（`useSessions` 读取 `parentId`，bash 示例是第三方姿态的范例）。Trajectory/waterfall 工具视图 slot 共享此形状，并随各自的渲染点落地（RendersCheck 会拒绝没有任何渲染方的声明）。
+工具行同样是 slot：独立工具环（`ToolViewRegistry`／`ctx.toolviews`／outlet）已经退役。聊天配置项声明键控的 `'conversation.chat.toolview'` 空位（Session scope；key 空间在运行时开放）；其渲染点逐行通过 `entryKey: toolName` 分发，并以 `GenericToolCard` 作为调用点 `fallback`。owner 载荷是统一的 `ToolRowOwnerProps`（`callId`／`toolName`／`block`／`openFile`），`ToolRowProps` 则预先将其与 Session 标准工具包组合。注册方只是普通插件：`ctx.slots.register({ name: 'conversation.chat.toolview', key: '<tool>', inject? }, Row)`，以 `inject: ['slots', 'conversation']` 作为加载顺序 seam（apply 在聊天注册后挂载 ConversationService，因此服务存在即可保证 slot 已声明）；Session 区分在组件内部完成（`useSessions` 读取 `parentId`，bash 示例是第三方姿态的范例）。Trajectory/waterfall 工具视图 slot 共享此形状，并随各自的渲染点落地（RendersCheck 会拒绝没有任何渲染方的声明）。
 
 todo 两个面就是在该形状上的两个注册项，都是普通注册方插件，`inject: ['slots', 'conversation']`。`TodoRow` 占用 `'conversation.chat.toolview'` 的 `todo_write` key，摘要该次调用「试图写入」的内容（从其 args 解析出 `<已完成>/<总数> 已完成 · <进行中条目>`；模型 JSON 残缺或形状不对时回落到通用摘要；非 ok 执行状态保留通用状态点，使被取消的调用绝不读成一次已完成的更新）。`TodoDock` 以 `order: -1` 占用 `'conversation.input.dock'` 列表 slot（位于队列行之上），是常驻的计划条：它从会话快照中选取 `todos` 并渲染 `TodoPanel`，后者接收纯列表，在列表为空时自我隐藏，折叠时收成标题加 `"<已完成>/<总数> tasks · <n> in progress"` 的表头（状态图标为 figma 的勾选／进行中／虚线未开始一组）。选取由 dock 适配器负责，因此面板保持为其 props 的纯函数；常驻列表放在此处而非行内，行才能保持单行。输入区 composer 链隐藏的一切（例如 ui-question 对 `conversation.composer` 的接管）也会隐藏整个 dock，包括这条计划条。
 
diff --git a/packages/client/ui-conversation/src/client/apply.ts b/packages/client/ui-conversation/src/client/apply.ts
index 12b4bd1f79..68df3a6da0 100644
--- a/packages/client/ui-conversation/src/client/apply.ts
+++ b/packages/client/ui-conversation/src/client/apply.ts
@@ -7,6 +7,7 @@ import type { ViewTab } from './contract/views.ts'
 import type {
   ChatViewInjected, ComposerBarInjected, ConversationInjected, ConversationSessionInjected, DetailsInjected,
 } from './contract/slots.ts'
+import { resolveToolPath } from './contract/tool-call-model.ts'
 import { createChatStore } from './stores.ts'
 import { ConversationService } from './service.ts'
 import { InputHub } from './input/hub.ts'
@@ -170,6 +171,13 @@ export function apply(ctx: Context): void {
           actions.select(target)
           layout.openDetails()
         },
+        openFile: (path) => {
+          const cwd = sessions.list.getSnapshot().byId[sessionId]?.cwd
+          void workspaces.openPath(resolveToolPath(cwd, path)).catch(() => {
+            // Host/OS open failures stay silent in the chat row; the native
+            // app surfaces its own error dialog when the path is unusable.
+          })
+        },
         loadOlder: () => { void scoped.loadOlder() },
       }
     },
diff --git a/packages/client/ui-conversation/src/client/chat/ChatView.tsx b/packages/client/ui-conversation/src/client/chat/ChatView.tsx
index 2e32eea86c..5273c75357 100644
--- a/packages/client/ui-conversation/src/client/chat/ChatView.tsx
+++ b/packages/client/ui-conversation/src/client/chat/ChatView.tsx
@@ -25,7 +25,6 @@ import type {
 import type { SnapshotSelectorHook } from '@deepseek-ai/dsh-client-ui-slots'
 import { IconChevronDownOutline14 } from '@deepseek-ai/dsh-client-ui-primitives'
 import type { ChatViewSlotProps } from '../contract/slots.ts'
-import type { SelectionTarget } from '../contract/views.ts'
 import { deriveChatFlow, type ChatFlowItem } from './chat-flow.ts'
 import { AssistantMarkdown } from './AssistantMarkdown.tsx'
 import { GenericCommandCard } from './GenericCommandCard.tsx'
@@ -37,7 +36,7 @@ import css from './ChatView.module.css'
 
 const FOLLOW_THRESHOLD = 24
 
-type OpenDetails = (target: SelectionTarget) => void
+type OpenFile = (path: string) => void
 
 /** The declared toolview hole's render share (stable framework binding, passed through memoized rows). */
 type RenderToolRow = ChatViewSlotProps['renderSlot']
@@ -50,20 +49,18 @@ type UseConversation = SnapshotSelectorHook<ConversationSnapshot>
  *  top-level call (same registrations, same fallback), nested by the parent.
  *  A started-but-unsettled sub-call arrives as the RunningToolCall shape and
  *  renders the running state exactly as a native in-flight row. */
-const SubCallRow = memo(function SubCallRow({ renderSlot, node, onOpenDetails, selected, cwd }: {
+const SubCallRow = memo(function SubCallRow({ renderSlot, node, openFile, selected, cwd }: {
   renderSlot: RenderToolRow
   node: CodeSubCall
-  onOpenDetails: OpenDetails
+  openFile: OpenFile
   selected: boolean
   cwd: string | undefined
 }) {
   const settled = 'kind' in node
   const toolName = settled ? node.call?.name ?? '' : node.name
-  const seq = settled ? node.seq : node.time
   const owner = useMemo(() => ({
-    callId: node.callId, toolName, block: node, cwd,
-    openDetails: () => { onOpenDetails({ turnSeq: seq, callId: node.callId, toolName }) },
-  }), [node, toolName, seq, cwd, onOpenDetails])
+    callId: node.callId, toolName, block: node, openFile, cwd,
+  }), [node, toolName, openFile, cwd])
   return (
     <div className={css.callRow} data-selected={selected || undefined}>
       {renderSlot('conversation.chat.toolview', owner, {
@@ -80,15 +77,13 @@ const SubCallRow = memo(function SubCallRow({ renderSlot, node, onOpenDetails, s
  *  renders its logged sub-dispatches as always-visible indented rows —
  *  each one the same keyed-slot dispatch as a native top-level call. */
 const CallRow = memo(function CallRow({
-  renderSlot, callId, toolName, block, seq, onOpenDetails, selected, subCalls, selectedCallId, cwd,
+  renderSlot, callId, toolName, block, openFile, selected, subCalls, selectedCallId, cwd,
 }: {
   renderSlot: RenderToolRow
   callId: string
   toolName: string
   block: ToolResultNode | RunningToolCall
-  /** Surface seq for finalized results; the call's turn for running calls. */
-  seq: number
-  onOpenDetails: OpenDetails
+  openFile: OpenFile
   selected: boolean
   /** `run_code` sub-dispatches in dispatch order (reference-stable per
    *  parent; running entries settle in place); undefined for ordinary calls. */
@@ -99,9 +94,8 @@ const CallRow = memo(function CallRow({
   cwd: string | undefined
 }) {
   const owner = useMemo(() => ({
-    callId, toolName, block, cwd,
-    openDetails: () => { onOpenDetails({ turnSeq: seq, callId, toolName }) },
-  }), [callId, toolName, block, seq, cwd, onOpenDetails])
+    callId, toolName, block, openFile, cwd,
+  }), [callId, toolName, block, openFile, cwd])
   return (
     <div className={css.callRow} data-selected={selected || undefined}>
       {renderSlot('conversation.chat.toolview', owner, {
@@ -115,7 +109,7 @@ const CallRow = memo(function CallRow({
               key={node.callId}
               renderSlot={renderSlot}
               node={node}
-              onOpenDetails={onOpenDetails}
+              openFile={openFile}
               selected={node.callId === selectedCallId}
               cwd={cwd}
             />
@@ -127,10 +121,10 @@ const CallRow = memo(function CallRow({
 })
 
 /** Consecutive tool results as one step-run group (uniform 16px rhythm). */
-const ToolGroup = memo(function ToolGroup({ renderSlot, results, onOpenDetails, selectedCallId, codeDispatches, cwd }: {
+const ToolGroup = memo(function ToolGroup({ renderSlot, results, openFile, selectedCallId, codeDispatches, cwd }: {
   renderSlot: RenderToolRow
   results: readonly ToolResultNode[]
-  onOpenDetails: OpenDetails
+  openFile: OpenFile
   /** Only set when the selected call lives in THIS group, top-level or nested (memo economy). */
   selectedCallId: string | undefined
   /** Sub-dispatch index off the snapshot (map reference is chunk-storm stable). */
@@ -147,8 +141,7 @@ const ToolGroup = memo(function ToolGroup({ renderSlot, results, onOpenDetails,
           callId={node.callId}
           toolName={node.call?.name ?? ''}
           block={node}
-          seq={node.seq}
-          onOpenDetails={onOpenDetails}
+          openFile={openFile}
           selected={node.callId === selectedCallId}
           subCalls={codeDispatches.get(node.callId)}
           selectedCallId={selectedCallId}
@@ -229,7 +222,7 @@ function StreamingTail({ useSession, onGrow }: {
  * The chat view slot entry: pure component over the composed props (tool rows
  * render through the declared keyed hole's renderSlot share).
  */
-export function ChatView({ useSession, useSessions, useStore, renderSlot, sessionId, openDetails, loadOlder }: ChatViewSlotProps) {
+export function ChatView({ useSession, useSessions, useStore, renderSlot, sessionId, openFile, loadOlder }: ChatViewSlotProps) {
   const nodes = useSession(s => s.nodes)
   // Workspace root off the session list row: path summaries display relative to it.
   const cwd = useSessions(s => s.byId[sessionId]?.cwd)
@@ -330,7 +323,7 @@ export function ChatView({ useSession, useSessions, useStore, renderSlot, sessio
           key={item.key}
           renderSlot={renderSlot}
           results={item.results}
-          onOpenDetails={openDetails}
+          openFile={openFile}
           selectedCallId={inGroup ? selectedCallId : undefined}
           codeDispatches={codeDispatches}
           cwd={cwd}
@@ -373,8 +366,7 @@ export function ChatView({ useSession, useSessions, useStore, renderSlot, sessio
                   callId={call.callId}
                   toolName={call.name}
                   block={call}
-                  seq={call.turn}
-                  onOpenDetails={openDetails}
+                  openFile={openFile}
                   selected={call.callId === selectedCallId}
                   subCalls={codeDispatches.get(call.callId)}
                   selectedCallId={selectedCallId}
diff --git a/packages/client/ui-conversation/src/client/chat/GenericToolCard.tsx b/packages/client/ui-conversation/src/client/chat/GenericToolCard.tsx
index e5b5fb541b..7bd4f22b06 100644
--- a/packages/client/ui-conversation/src/client/chat/GenericToolCard.tsx
+++ b/packages/client/ui-conversation/src/client/chat/GenericToolCard.tsx
@@ -25,8 +25,9 @@ const VARIANT_ICONS: Record<ToolRowVariant, ReactNode> = {
   others: <IconSparkle16 size={14} />,
 }
 
-export function GenericToolCard({ toolName, block, cwd, openDetails }: ToolRowOwnerProps) {
+export function GenericToolCard({ toolName, block, cwd, openFile }: ToolRowOwnerProps) {
   const model = toolRowModel(toolName, block, cwd)
+  const singleFile = model.filePath !== undefined
   return (
     <ToolRow
       variant={model.variant}
@@ -34,9 +35,11 @@ export function GenericToolCard({ toolName, block, cwd, openDetails }: ToolRowOw
       icon={VARIANT_ICONS[model.variant]}
       title={model.title}
       summary={model.summary}
-      body={model.body}
+      // Single-file tools never expose an args body — the path link is the only action.
+      body={singleFile ? null : model.body}
       state={model.state}
-      onOpenDetails={openDetails}
+      filePath={model.filePath}
+      onOpenFile={singleFile ? openFile : undefined}
     />
   )
 }
diff --git a/packages/client/ui-conversation/src/client/chat/ToolRow.module.css b/packages/client/ui-conversation/src/client/chat/ToolRow.module.css
index 018529961f..7e2ed4db21 100644
--- a/packages/client/ui-conversation/src/client/chat/ToolRow.module.css
+++ b/packages/client/ui-conversation/src/client/chat/ToolRow.module.css
@@ -41,10 +41,9 @@
   90%, 100% { left: 100%; }
 }
 
-/* Clickable rows keep only the cursor affordance — no hover fill. */
-.row[data-clickable] {
+/* Expand-on-row (Think / code): pointer only — no row fill hover. */
+.row[data-expandable] {
   cursor: pointer;
-  border-radius: 6px;
 }
 
 .leading {
@@ -143,6 +142,29 @@ button.leading {
   color: var(--dsw-alias-label-tertiary);
 }
 
+/* File-tool path: same geometry as .summary; hover underline + pointer. */
+.fileLink {
+  flex: 1 1 auto;
+  min-width: 0;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+  margin: 0;
+  padding: 0;
+  border: none;
+  background: none;
+  font: inherit;
+  text-align: left;
+  font-size: 14px;
+  line-height: 24px;
+  color: var(--dsw-alias-label-tertiary);
+  cursor: pointer;
+}
+
+.fileLink:hover {
+  text-decoration: underline;
+}
+
 /* Expanded body: pad-left 22 indented gray text, no border, no fill. */
 .body {
   padding: 4px 0 4px 22px;
diff --git a/packages/client/ui-conversation/src/client/chat/ToolRow.tsx b/packages/client/ui-conversation/src/client/chat/ToolRow.tsx
index 5c5d059292..9395813910 100644
--- a/packages/client/ui-conversation/src/client/chat/ToolRow.tsx
+++ b/packages/client/ui-conversation/src/client/chat/ToolRow.tsx
@@ -2,9 +2,8 @@
 // 16px leading slot (state dot / tool icon, chevron on hover or expanded) + title +
 // separator dot + FILL-truncated summary. Expanded body is indented gray text;
 // no inline output (full results live in the details panel). Expand state is
-// component-local view state; row click hands the selection off to the owner.
-// TODO(ux): converge every chat-tab tool row on in-place expansion for its
-// expandable content, retiring the details-panel handoff where feasible.
+// component-local view state. File-tool summaries are path links that open
+// through the host; the row itself is not a details-panel control.
 
 import { useState, type KeyboardEvent, type MouseEvent, type ReactNode } from 'react'
 import clsx from 'clsx'
@@ -26,8 +25,13 @@ export interface ToolRowProps {
   state: ToolRowState
   /** Makes the row itself the expand control instead of only its leading icon. */
   expandOnRowClick?: boolean | undefined
-  /** Selection handoff (row click), already bound to this call by the owner. */
-  onOpenDetails?: (() => void) | undefined
+  /**
+   * Filesystem path from tool args; when set with onOpenFile, the summary
+   * renders as a hover-underline link that opens the host default app.
+   */
+  filePath?: string | undefined
+  /** Open the path with the host OS default application (already cwd-resolved). */
+  onOpenFile?: ((path: string) => void) | undefined
 }
 
 /** Leading-slot state substitution: the tool icon yields to the terminal state
@@ -50,10 +54,15 @@ export function ToolRow({
   body,
   state,
   expandOnRowClick = false,
-  onOpenDetails,
+  filePath,
+  onOpenFile,
 }: ToolRowProps) {
   const [expanded, setExpanded] = useState(false)
-  const expandable = body !== null
+  // A row that names a single file keeps one interaction (open that path);
+  // args expand is off whether or not the open callback is wired yet.
+  const singleFile = filePath !== undefined
+  const fileLink = singleFile && onOpenFile !== undefined
+  const expandable = body !== null && !singleFile
   const open = expanded && expandable
   const rowExpands = expandable && expandOnRowClick
   const toggleExpand = () => {
@@ -68,6 +77,10 @@ export function ToolRow({
     event.preventDefault()
     toggleExpand()
   }
+  const openFile = (event: MouseEvent<HTMLButtonElement>) => {
+    event.stopPropagation()
+    if (filePath !== undefined) onOpenFile?.(filePath)
+  }
   // Expandable rows preview the toggle on hover: the tool icon yields to a
   // down chevron (CSS swap on .row:hover); state dots still take precedence.
   const collapsedIcon = expandable
@@ -85,11 +98,11 @@ export function ToolRow({
     <div className={css.root} data-variant={variant} data-tool={toolName} data-state={state}>
       <div
         className={css.row}
-        data-clickable={rowExpands || onOpenDetails !== undefined || undefined}
+        data-expandable={rowExpands || undefined}
         role={rowExpands ? 'button' : undefined}
         tabIndex={rowExpands ? 0 : undefined}
         aria-expanded={rowExpands ? open : undefined}
-        onClick={rowExpands ? toggleExpand : onOpenDetails}
+        onClick={rowExpands ? toggleExpand : undefined}
         onKeyDown={rowExpands ? toggleFromKeyboard : undefined}
       >
         {expandable && !rowExpands ? (
@@ -110,7 +123,17 @@ export function ToolRow({
         {!open && (
           <>
             <span className={css.sep} aria-hidden />
-            <span className={css.summary}>{summary}</span>
+            {fileLink ? (
+              <button
+                type="button"
+                className={css.fileLink}
+                onClick={openFile}
+              >
+                {summary}
+              </button>
+            ) : (
+              <span className={css.summary}>{summary}</span>
+            )}
           </>
         )}
       </div>
diff --git a/packages/client/ui-conversation/src/client/contract/slots.ts b/packages/client/ui-conversation/src/client/contract/slots.ts
index 690e925f03..d390ffc007 100644
--- a/packages/client/ui-conversation/src/client/contract/slots.ts
+++ b/packages/client/ui-conversation/src/client/contract/slots.ts
@@ -154,8 +154,11 @@ export interface ToolRowOwnerProps {
   block: ToolCallBlock
   /** Session workspace root; path summaries display relative to it. */
   cwd?: string | undefined
-  /** Open the details panel for this call (session-level facility, supplied by the view). */
-  openDetails: () => void
+  /**
+   * Open a tool-arg filesystem path with the host OS default application.
+   * The chat view resolves relative paths against the session cwd.
+   */
+  openFile: (path: string) => void
 }
 
 /**
@@ -310,6 +313,11 @@ export type ConversationSessionSlotProps =
 export interface ChatViewInjected {
   /** Selection write + details panel opening in one gesture (store action + layout orchestration). */
   openDetails: (target: SelectionTarget) => void
+  /**
+   * Open a tool-arg filesystem path with the host OS default application
+   * (relative paths resolve against the session cwd).
+   */
+  openFile: (path: string) => void
   loadOlder: () => void
 }
 
diff --git a/packages/client/ui-conversation/src/client/contract/tool-call-model.ts b/packages/client/ui-conversation/src/client/contract/tool-call-model.ts
index c7db85b0aa..04a8c66d40 100644
--- a/packages/client/ui-conversation/src/client/contract/tool-call-model.ts
+++ b/packages/client/ui-conversation/src/client/contract/tool-call-model.ts
@@ -62,6 +62,12 @@ export interface ToolRowModel {
   variant: ToolRowVariant
   title: string
   summary: string
+  /**
+   * Filesystem path from args (`path` / `file_path`) when the row is a file
+   * tool; absent for URL reads and non-file tools. The chat view resolves
+   * relative values against the session cwd before opening.
+   */
+  filePath: string | undefined
   /** Expanded-body text (pretty args); null = row not expandable. */
   body: string | null
   state: ToolRowState
@@ -121,6 +127,35 @@ function deriveSummary(variant: ToolRowVariant, argsRaw: string): string {
   return firstLine(argsRaw)
 }
 
+/** Path keys only — never `url` (web_fetch lands on the read variant). */
+const FILE_PATH_KEYS = ['path', 'file_path'] as const
+
+/** File-tool variants whose summary may be an openable workspace path. */
+const FILE_PATH_VARIANTS: ReadonlySet<ToolRowVariant> = new Set(['read', 'write', 'edit'])
+
+function deriveFilePath(variant: ToolRowVariant, argsRaw: string): string | undefined {
+  if (!FILE_PATH_VARIANTS.has(variant)) return undefined
+  const parsed = parseArgs(argsRaw)
+  if (typeof parsed !== 'object' || parsed === null) return undefined
+  const picked = pickString(parsed as Record<string, unknown>, FILE_PATH_KEYS)
+  return picked === undefined ? undefined : firstLine(picked)
+}
+
+/**
+ * Resolve a tool-arg path against the session cwd for host.openPath.
+ * Absolute POSIX/Windows paths pass through; relative paths join under cwd.
+ * @param cwd - session working directory (may be absent for ungrouped sessions).
+ * @param path - path as carried in tool args.
+ * @returns a host-facing path string.
+ */
+export function resolveToolPath(cwd: string | undefined, path: string): string {
+  if (path.startsWith('/') || /^[A-Za-z]:[/\\]/.test(path) || path.startsWith('\\\\')) return path
+  if (cwd === undefined || cwd === '') return path
+  const base = cwd.replace(/[/\\]+$/, '')
+  const rel = path.replace(/^[/\\]+/, '')
+  return `${base}/${rel}`
+}
+
 function deriveBody(variant: ToolRowVariant, argsRaw: string): string | null {
   if (argsRaw === '') return null
   const parsed = parseArgs(argsRaw)
@@ -159,6 +194,7 @@ export function toolRowModel(toolName: string, block: ToolCallBlock, cwd?: strin
     variant,
     title: toolTitle ?? VARIANT_TITLES[variant],
     summary,
+    filePath: deriveFilePath(variant, argsRaw),
     body: deriveBody(variant, argsRaw),
     state,
   }
diff --git a/packages/client/ui-conversation/src/client/toolviews/bash-sample.module.css b/packages/client/ui-conversation/src/client/toolviews/bash-sample.module.css
index a79faf30f1..2e5d601e62 100644
--- a/packages/client/ui-conversation/src/client/toolviews/bash-sample.module.css
+++ b/packages/client/ui-conversation/src/client/toolviews/bash-sample.module.css
@@ -7,8 +7,6 @@
   align-items: center;
   height: 24px;
   min-width: 0;
-  cursor: pointer;
-  border-radius: 6px;
 }
 
 /* Running sweep glare — same deepsuite ShimmerText pattern as ToolRow. */
diff --git a/packages/client/ui-conversation/src/client/toolviews/bash-sample.tsx b/packages/client/ui-conversation/src/client/toolviews/bash-sample.tsx
index fbb1104eca..d972a35274 100644
--- a/packages/client/ui-conversation/src/client/toolviews/bash-sample.tsx
+++ b/packages/client/ui-conversation/src/client/toolviews/bash-sample.tsx
@@ -30,7 +30,7 @@ function stateStatus(state: ToolRowState): string | null {
 }
 
 /** Bash row: icon + Bash · {description}, matching the shared ToolRow chrome. */
-export function BashRow({ toolName, block, openDetails, sessionId, useSessions }: ToolRowProps) {
+export function BashRow({ toolName, block, sessionId, useSessions }: ToolRowProps) {
   const model = toolRowModel(toolName, block)
   const isChild = useSessions(list => list.byId[sessionId]?.parentId !== undefined)
   const status = stateStatus(model.state)
@@ -40,8 +40,6 @@ export function BashRow({ toolName, block, openDetails, sessionId, useSessions }
       data-sample={isChild ? 'bash-scoped' : 'bash-global'}
       data-variant="bash"
       data-state={model.state}
-      data-clickable
-      onClick={openDetails}
     >
       <span className={css.leading}>{leadingFor(model.state)}</span>
       {status !== null && <span className={css.visuallyHidden}>{status}</span>}
diff --git a/packages/client/ui-conversation/src/client/toolviews/todo-row.module.css b/packages/client/ui-conversation/src/client/toolviews/todo-row.module.css
index 1a1b142b3a..8e59b36625 100644
--- a/packages/client/ui-conversation/src/client/toolviews/todo-row.module.css
+++ b/packages/client/ui-conversation/src/client/toolviews/todo-row.module.css
@@ -6,8 +6,6 @@
   align-items: center;
   height: 24px;
   min-width: 0;
-  cursor: pointer;
-  border-radius: 6px;
 }
 
 .leading {
diff --git a/packages/client/ui-conversation/src/client/toolviews/todo-row.tsx b/packages/client/ui-conversation/src/client/toolviews/todo-row.tsx
index a47322b614..67732a3650 100644
--- a/packages/client/ui-conversation/src/client/toolviews/todo-row.tsx
+++ b/packages/client/ui-conversation/src/client/toolviews/todo-row.tsx
@@ -5,7 +5,6 @@
 // durable list itself renders in the TodoPanel above the composer, so the
 // row stays one line. Chrome matches ToolRow (figma 780:53675).
 
-import type { KeyboardEvent } from 'react'
 import type { Context } from 'cordis'
 import { IconChecklistOutline16, StateDot } from '@deepseek-ai/dsh-client-ui-primitives'
 import type { ToolRowProps } from '../contract/slots.ts'
@@ -51,29 +50,18 @@ function leadingFor(state: ToolRowState) {
   }
 }
 
-/** One-line plan update row (click opens the raw args in details). Non-ok
- *  execution states keep the generic row's dot semantics — a cancelled call
- *  wrote no todo/write, so it must not read as a completed update. */
-export function TodoRow({ toolName, block, openDetails }: ToolRowProps) {
+/** One-line plan update row. Non-ok execution states keep the generic row's
+ *  dot semantics — a cancelled call wrote no todo/write, so it must not read
+ *  as a completed update. */
+export function TodoRow({ toolName, block }: ToolRowProps) {
   const model = toolRowModel(toolName, block)
   const argsRaw = ('kind' in block ? block.call?.argsRaw : block.argsRaw) ?? ''
   const summary = summarize(argsRaw) ?? model.summary
-  // Button semantics, not a <button>: the row carries inline spans a button
-  // would flatten, and ToolRow takes the same role/tabIndex/Enter-Space route.
-  const openFromKeyboard = (event: KeyboardEvent<HTMLDivElement>) => {
-    if (event.key !== 'Enter' && event.key !== ' ') return
-    event.preventDefault()
-    openDetails()
-  }
   return (
     <div
       className={css.row}
       data-sample="todo-row"
       data-state={model.state}
-      role="button"
-      tabIndex={0}
-      onClick={openDetails}
-      onKeyDown={openFromKeyboard}
     >
       <span className={css.leading} aria-hidden>{leadingFor(model.state)}</span>
       <span className={css.title}>更新任务清单</span>
diff --git a/packages/client/ui-conversation/tests/apply-inject.spec.tsx b/packages/client/ui-conversation/tests/apply-inject.spec.tsx
index 885cdd2523..3320c79d3a 100644
--- a/packages/client/ui-conversation/tests/apply-inject.spec.tsx
+++ b/packages/client/ui-conversation/tests/apply-inject.spec.tsx
@@ -107,6 +107,7 @@ async function bench() {
   const workspacesFake = {
     list: workspaceStore,
     connectWorkspace: vi.fn(async () => ROOT),
+    openPath: vi.fn(async () => {}),
   }
   ctx.provide('workspaces', workspacesFake)
   const layoutFake = { openDetails: vi.fn(), closeDetails: vi.fn() }
@@ -259,6 +260,15 @@ describe('conversation slot inject surface', () => {
     expect(conv.instance).toBe(instance)
   })
 
+  it('openFile (chat view face) resolves against session cwd and calls workspaces.openPath', async () => {
+    const b = await bench()
+    const { injected } = b.chatViewSurface(ROOT)
+    injected.openFile('src/a.ts')
+    await vi.waitFor(() => {
+      expect(b.workspacesFake.openPath).toHaveBeenCalledWith('/proj/src/a.ts')
+    })
+  })
+
   it('routes navigation and workspace switching through the runtime owners, carrying the draft', async () => {
     const b = await bench()
     const { injected } = b.conversationSurface(ROOT)
diff --git a/packages/client/ui-conversation/tests/chat-apply.spec.tsx b/packages/client/ui-conversation/tests/chat-apply.spec.tsx
index dab04e94c7..afafafa3dc 100644
--- a/packages/client/ui-conversation/tests/chat-apply.spec.tsx
+++ b/packages/client/ui-conversation/tests/chat-apply.spec.tsx
@@ -48,6 +48,7 @@ async function bench() {
   ctx.provide('workspaces', {
     startSession: vi.fn(),
     sendSession: vi.fn(),
+    openPath: vi.fn(async () => {}),
   })
   ctx.provide('layout', { openDetails: vi.fn(), closeDetails: vi.fn() })
   ctx.provide('locale', { bind: () => (key: string) => key })
diff --git a/packages/client/ui-conversation/tests/chat-code-subcalls.spec.tsx b/packages/client/ui-conversation/tests/chat-code-subcalls.spec.tsx
index bfbc14b17a..39d2b8283a 100644
--- a/packages/client/ui-conversation/tests/chat-code-subcalls.spec.tsx
+++ b/packages/client/ui-conversation/tests/chat-code-subcalls.spec.tsx
@@ -5,7 +5,7 @@
 // always-visible nested rows through the SAME keyed toolview hole — the bash
 // sub-call lands in the bash sample plugin's registration exactly like a
 // top-level bash row, unregistered sub-tools fall back to GenericToolCard —
-// and a sub-row click opens details for the sub-callId. Running parents
+// and a file sub-row click opens the host path. Running parents
 // (runningCalls) nest their so-far dispatches the same way.
 
 import { Context } from 'cordis'
@@ -114,14 +114,16 @@ async function bench(snapshot: ConversationSnapshot) {
     open: vi.fn(),
   }
   ctx.provide('sessions', sessionsFake)
-  ctx.provide('workspaces', {
+  const workspaces = {
     list: createSnapshotStore<WorkspaceListState>({
       items: [], state: 'idle', phase: 'ready', error: null,
       baselinesReady: true, recentWorkspaceId: undefined,
     }),
     startSession: vi.fn(),
     sendSession: vi.fn(),
-  })
+    openPath: vi.fn(async () => {}),
+  }
+  ctx.provide('workspaces', workspaces)
   ctx.provide('layout', layout)
   ctx.provide('i18n', { bind: () => (key: string) => key })
 
@@ -136,7 +138,7 @@ async function bench(snapshot: ConversationSnapshot) {
 
   const fiber = ctx.plugin({ inject: [...inject], apply })
   await fiber.await()
-  return { ctx, slots, fiber, session, layout }
+  return { ctx, slots, fiber, session, layout, workspaces }
 }
 
 function mountApp(slots: SlotsService) {
@@ -220,15 +222,21 @@ describe('run_code sub-calls through the real chat machinery', () => {
     expect(nested).not.toBeNull()
   })
 
-  it('a sub-row click opens details for the sub-callId', async () => {
+  it('a file sub-row click opens the host path; bash sub-rows do not open details', async () => {
     const parent = 'call-64'
     const dispatches = new Map([[parent, [
-      subCall(11, parent, 1, 'bash', { command: 'ls notes', description: 'List notes' }, 'demo.txt'),
+      subCall(11, parent, 1, 'read', { path: 'notes/demo.txt' }, 'ok'),
+      subCall(12, parent, 2, 'bash', { command: 'ls notes', description: 'List notes' }, 'demo.txt'),
     ]]])
     const b = await bench(snapshotWith([codeResult(10, parent)], dispatches))
     const view = mountApp(b.slots)
+    view.getByText('notes/demo.txt').click()
+    expect(b.layout.openDetails).not.toHaveBeenCalled()
+    await vi.waitFor(() => {
+      expect(b.workspaces.openPath).toHaveBeenCalledWith('notes/demo.txt')
+    })
     view.getByText('List notes').click()
-    expect(b.layout.openDetails).toHaveBeenCalledTimes(1)
+    expect(b.layout.openDetails).not.toHaveBeenCalled()
   })
 
   it('a RUNNING run_code call nests its so-far dispatches under the spinner row', async () => {
diff --git a/packages/client/ui-conversation/tests/chat-stats-bash-sample.spec.tsx b/packages/client/ui-conversation/tests/chat-stats-bash-sample.spec.tsx
index 9621abbf05..bee3e89e2e 100644
--- a/packages/client/ui-conversation/tests/chat-stats-bash-sample.spec.tsx
+++ b/packages/client/ui-conversation/tests/chat-stats-bash-sample.spec.tsx
@@ -5,7 +5,7 @@
 // standard useSessions kit (no registry predicates — tool ring dissolved).
 
 import { afterEach, describe, expect, it, vi } from 'vitest'
-import { act, cleanup, fireEvent, render } from '@testing-library/react'
+import { act, cleanup, render } from '@testing-library/react'
 import type {
   AssistantMessageNode, ConversationSnapshot, SessionId, SessionListState, ToolResultNode,
 } from '@deepseek-ai/dsh-client-runtime/client'
@@ -133,10 +133,9 @@ describe('bash sample row', () => {
 
   const rowProps = (sessionId: SessionId, over?: {
     store?: ReturnType<typeof listStore>
-    openDetails?: () => void
   }): ToolRowProps => ({
     callId: 'c1', toolName: 'bash', block: result('c1'),
-    openDetails: over?.openDetails ?? vi.fn(),
+    openFile: vi.fn(),
     sessionId,
     useSessions: bindSnapshotSelector(over?.store ?? listStore()),
   } as unknown as ToolRowProps)
@@ -169,21 +168,17 @@ describe('bash sample row', () => {
     expect(view.container.querySelector('[data-sample="bash-scoped"]')).not.toBeNull()
   })
 
-  it('summarizes as Bash · description and hands clicks to openDetails on both arms', () => {
-    const openGlobal = vi.fn()
-    const global = render(<BashRow {...rowProps(ROOT, { openDetails: openGlobal })} />)
+  it('summarizes as Bash · description on both arms without row click targets', () => {
+    const global = render(<BashRow {...rowProps(ROOT)} />)
     // Two renders share document.body: query inside each container.
     const globalRow = global.container.querySelector('[data-sample="bash-global"]')!
     expect(globalRow.textContent).toContain('Bash')
     expect(globalRow.textContent).toContain('Build')
-    fireEvent.click(globalRow)
-    expect(openGlobal).toHaveBeenCalledTimes(1)
-    const openScoped = vi.fn()
-    const scoped = render(<BashRow {...rowProps(CHILD, { openDetails: openScoped })} />)
+    expect(globalRow.getAttribute('data-clickable')).toBeNull()
+    const scoped = render(<BashRow {...rowProps(CHILD)} />)
     const scopedRow = scoped.container.querySelector('[data-sample="bash-scoped"]')!
     expect(scopedRow.textContent).toContain('Bash')
     expect(scopedRow.textContent).toContain('Build')
-    fireEvent.click(scopedRow)
-    expect(openScoped).toHaveBeenCalledTimes(1)
+    expect(scopedRow.getAttribute('data-clickable')).toBeNull()
   })
 })
diff --git a/packages/client/ui-conversation/tests/chat-tool-row.spec.tsx b/packages/client/ui-conversation/tests/chat-tool-row.spec.tsx
index 63f2da6586..4b17c616cf 100644
--- a/packages/client/ui-conversation/tests/chat-tool-row.spec.tsx
+++ b/packages/client/ui-conversation/tests/chat-tool-row.spec.tsx
@@ -4,7 +4,7 @@ import { cleanup, fireEvent, render } from '@testing-library/react'
 
 afterEach(cleanup)
 import type { RunningToolCall, ToolResultNode } from '@deepseek-ai/dsh-client-runtime/client'
-import { classifyTool, toolRowModel } from '../src/client/contract/tool-call-model.ts'
+import { classifyTool, resolveToolPath, toolRowModel } from '../src/client/contract/tool-call-model.ts'
 import { AssistantMarkdown } from '../src/client/chat/AssistantMarkdown.tsx'
 import { ToolRow } from '../src/client/chat/ToolRow.tsx'
 import { GenericToolCard } from '../src/client/chat/GenericToolCard.tsx'
@@ -64,6 +64,22 @@ describe('tool-call-model', () => {
     expect(toolRowModel('', running({ argsRaw: '' })).summary).toBe('c1')
   })
 
+  it('exposes filePath for path/file_path args and skips URL-only reads', () => {
+    expect(toolRowModel('read', running({ name: 'read', argsRaw: '{"path":"src/a.ts"}' })).filePath).toBe('src/a.ts')
+    expect(toolRowModel('write', running({ name: 'write', argsRaw: '{"file_path":"src/a.ts"}' })).filePath).toBe('src/a.ts')
+    expect(toolRowModel('edit', running({ name: 'edit', argsRaw: '{"file_path":"src/a.ts"}' })).filePath).toBe('src/a.ts')
+    expect(toolRowModel('web_fetch', running({ name: 'web_fetch', argsRaw: '{"url":"https://example.com"}' })).filePath)
+      .toBeUndefined()
+    expect(toolRowModel('bash', running()).filePath).toBeUndefined()
+  })
+
+  it('resolveToolPath joins relative paths under cwd and passes absolute through', () => {
+    expect(resolveToolPath('/w', 'src/a.ts')).toBe('/w/src/a.ts')
+    expect(resolveToolPath('/w/', '/abs/a.ts')).toBe('/abs/a.ts')
+    expect(resolveToolPath(undefined, 'src/a.ts')).toBe('src/a.ts')
+    expect(resolveToolPath('/w', 'C:\\x\\a.ts')).toBe('C:\\x\\a.ts')
+  })
+
   it('displays workspace-rooted paths relative to the session cwd', () => {
     const cwd = '/Users/u/ws/'
     expect(toolRowModel('edit', running({ name: 'edit', argsRaw: '{"file_path":"/Users/u/ws/src/x.ts"}' }), cwd).summary).toBe('src/x.ts')
@@ -149,13 +165,34 @@ describe('ToolRow', () => {
     expect(view.queryByTestId('tool-icon')).not.toBeNull()
   })
 
-  it('row click hands off to onOpenDetails; the expand toggle does not', () => {
+  it('file-path summary opens through onOpenFile; the leading slot is not an expand control', () => {
     const open = vi.fn()
-    const view = render(<ToolRow {...rowProps} onOpenDetails={open} />)
+    const view = render(
+      <ToolRow {...rowProps} variant="read" title="Read" summary="src/a.ts" filePath="src/a.ts" onOpenFile={open} />,
+    )
+    fireEvent.click(view.getByText('src/a.ts'))
+    expect(open).toHaveBeenCalledWith('src/a.ts')
+    // Only the path link is a button — no args-expand affordance on file rows.
+    expect(view.container.querySelectorAll('button')).toHaveLength(1)
+    expect(view.container.querySelector('[aria-expanded]')).toBeNull()
+    expect(view.queryByText(/"a": 1/)).toBeNull()
+  })
+
+  it('a single-file path disables expand even when onOpenFile is absent', () => {
+    const view = render(
+      <ToolRow {...rowProps} variant="write" title="Write" summary="作文.md" filePath="作文.md" />,
+    )
+    expect(view.container.querySelector('button')).toBeNull()
+    expect(view.container.querySelector('[aria-expanded]')).toBeNull()
+    fireEvent.click(view.getByText('作文.md'))
+    expect(view.queryByText(/"a": 1/)).toBeNull()
+  })
+
+  it('non-file rows do not open anything when the summary is clicked', () => {
+    const open = vi.fn()
+    const view = render(<ToolRow {...rowProps} onOpenFile={open} />)
     fireEvent.click(view.getByText('List files'))
-    expect(open).toHaveBeenCalledTimes(1)
-    fireEvent.click(view.container.querySelector('button')!)
-    expect(open).toHaveBeenCalledTimes(1)
+    expect(open).not.toHaveBeenCalled()
   })
 })
 
@@ -180,7 +217,7 @@ describe('ThinkRow', () => {
 
 describe('GenericToolCard', () => {
   const props = (toolName: string, block: RunningToolCall | ToolResultNode): ToolRowOwnerProps => ({
-    callId: 'c1', toolName, block, openDetails: vi.fn(),
+    callId: 'c1', toolName, block, openFile: vi.fn(),
   })
 
   it('renders the classified variant row from the frozen slice', () => {
@@ -225,10 +262,15 @@ describe('GenericToolCard', () => {
     expect(view.container.querySelector('svg')).not.toBeNull()
   })
 
-  it('row click reaches openDetails', () => {
-    const p = props('bash', result())
-    const view = render(<GenericToolCard {...p} />)
-    fireEvent.click(view.getByText('List files'))
-    expect(p.openDetails).toHaveBeenCalledTimes(1)
+  it('file-path summary click reaches openFile; bash summary does not', () => {
+    const file = props('read', running({ name: 'read', argsRaw: '{"path":"src/x.ts"}' }))
+    const fileView = render(<GenericToolCard {...file} />)
+    fireEvent.click(fileView.getByText('src/x.ts'))
+    expect(file.openFile).toHaveBeenCalledWith('src/x.ts')
+
+    const bash = props('bash', result())
+    const bashView = render(<GenericToolCard {...bash} />)
+    fireEvent.click(bashView.getByText('List files'))
+    expect(bash.openFile).not.toHaveBeenCalled()
   })
 })
diff --git a/packages/client/ui-conversation/tests/chat-toolview-slot.spec.tsx b/packages/client/ui-conversation/tests/chat-toolview-slot.spec.tsx
index 5908743d55..784c04c571 100644
--- a/packages/client/ui-conversation/tests/chat-toolview-slot.spec.tsx
+++ b/packages/client/ui-conversation/tests/chat-toolview-slot.spec.tsx
@@ -121,14 +121,16 @@ async function bench(nodes: ToolResultNode[]) {
     open: vi.fn(),
     updateIntent: vi.fn(),
   })
-  ctx.provide('workspaces', {
+  const workspaces = {
     list: createSnapshotStore<WorkspaceListState>({
       items: [], state: 'idle', phase: 'ready', error: null,
       baselinesReady: true, recentWorkspaceId: undefined,
     }),
     startSession: vi.fn(),
     sendSession: vi.fn(),
-  })
+    openPath: vi.fn(async () => {}),
+  }
+  ctx.provide('workspaces', workspaces)
   ctx.provide('layout', layout)
   ctx.provide('locale', { bind: () => (key: string) => key })
 
@@ -143,7 +145,7 @@ async function bench(nodes: ToolResultNode[]) {
 
   const fiber = ctx.plugin({ inject: [...inject], apply })
   await fiber.await()
-  return { ctx, slots, fiber, session, list, layout }
+  return { ctx, slots, fiber, session, list, layout, workspaces }
 }
 
 /** Render the whole tree through the ctx-level root seam (the shell's own entry). */
@@ -186,11 +188,22 @@ describe('keyed toolview hole through the real machinery', () => {
     expect(mounted!.querySelector('pre.shiki')?.textContent).toBe(code)
   })
 
-  it('row clicks travel owner openDetails → chat inject → layout orchestration', async () => {
+  it('file-path clicks travel owner openFile → chat inject → workspaces.openPath', async () => {
+    const b = await bench([toolResult(3, 'c1', 'read', '{"path":"src/a.ts"}')])
+    const view = mountApp(b.slots)
+    view.getByText('src/a.ts').click()
+    expect(b.layout.openDetails).not.toHaveBeenCalled()
+    await vi.waitFor(() => {
+      expect(b.workspaces.openPath).toHaveBeenCalledWith('src/a.ts')
+    })
+  })
+
+  it('bash summary clicks do not open details or host paths', async () => {
     const b = await bench([toolResult(3, 'c1', 'bash')])
     const view = mountApp(b.slots)
     view.getByText('Build').click()
-    expect(b.layout.openDetails).toHaveBeenCalledTimes(1)
+    expect(b.layout.openDetails).not.toHaveBeenCalled()
+    expect(b.workspaces.openPath).not.toHaveBeenCalled()
   })
 
   it('a live keyed registration takes over its tool row and unload reverts to the fallback', async () => {
@@ -271,6 +284,7 @@ describe('registrant load-order seam', () => {
       }),
       startSession: vi.fn(),
       sendSession: vi.fn(),
+      openPath: vi.fn(async () => {}),
     })
     ctx.provide('layout', { openDetails: vi.fn(), closeDetails: vi.fn() })
     ctx.provide('locale', { bind: () => (key: string) => key })
diff --git a/packages/client/ui-conversation/tests/chat-view.spec.tsx b/packages/client/ui-conversation/tests/chat-view.spec.tsx
index 419a91906c..56ec1245e1 100644
--- a/packages/client/ui-conversation/tests/chat-view.spec.tsx
+++ b/packages/client/ui-conversation/tests/chat-view.spec.tsx
@@ -88,6 +88,7 @@ function emptyWorkspaces() {
 function makeHarness(init?: Partial<ConversationSnapshot>) {
   const { set, source } = makeSource(init)
   const openDetails = vi.fn<(t: SelectionTarget) => void>()
+  const openFile = vi.fn<(path: string) => void>()
   const loadOlder = vi.fn()
   // Selection rides the REAL chat store (same construction path as
   // production; the view reads it through the PropsStore useStore share).
@@ -113,10 +114,11 @@ function makeHarness(init?: Partial<ConversationSnapshot>) {
     renderSlot,
     SessionProvider: SessionProviderStub,
     openDetails,
+    openFile,
     loadOlder,
   }
   const setSelection = (next: SelectionTarget | null): void => { chat.actions.select(next) }
-  return { set, ChatView, props, openDetails, loadOlder, setSelection }
+  return { set, ChatView, props, openDetails, openFile, loadOlder, setSelection }
 }
 
 describe('chat-flow derivation', () => {
@@ -282,16 +284,31 @@ describe('ChatView', () => {
     expect(view.getByText(/"command": "cmd-a"/)).toBeTruthy()
   })
 
-  it('clicking a tool row opens details with callId and toolName; selection marks data-selected', () => {
+  it('clicking a bash summary does not open details; selection still marks data-selected', () => {
     const h = makeHarness({ nodes: [toolResult(3, 'a')] })
     const view = render(<h.ChatView {...h.props} />)
     fireEvent.click(view.getByText('run a'))
-    expect(h.openDetails).toHaveBeenCalledWith({ turnSeq: 3, callId: 'a', toolName: 'bash' })
+    expect(h.openDetails).not.toHaveBeenCalled()
+    expect(h.openFile).not.toHaveBeenCalled()
     expect(view.container.querySelector('[data-selected]')).toBeNull()
     act(() => { h.setSelection({ turnSeq: 3, callId: 'a', toolName: 'bash' }) })
     expect(view.container.querySelector('[data-selected]')).not.toBeNull()
   })
 
+  it('clicking a file-tool path summary opens the host file, not details', () => {
+    const h = makeHarness({
+      nodes: [{
+        kind: 'tool-result', seq: 3, time: 3_000, callId: 'r1',
+        call: { name: 'read', argsRaw: '{"path":"src/a.ts"}' },
+        callTime: 2_500, content: [], isError: false, callView: null, resultView: null,
+      }],
+    })
+    const view = render(<h.ChatView {...h.props} />)
+    fireEvent.click(view.getByText('src/a.ts'))
+    expect(h.openFile).toHaveBeenCalledWith('src/a.ts')
+    expect(h.openDetails).not.toHaveBeenCalled()
+  })
+
   it('running calls render as a live tool group with the running state', () => {
     const h = makeHarness({ runningCalls: [runningCall('r1')], running: true })
     const view = render(<h.ChatView {...h.props} />)
diff --git a/packages/client/ui-conversation/tests/coverage-tails.spec.tsx b/packages/client/ui-conversation/tests/coverage-tails.spec.tsx
index ccac62c74f..90628f64ee 100644
--- a/packages/client/ui-conversation/tests/coverage-tails.spec.tsx
+++ b/packages/client/ui-conversation/tests/coverage-tails.spec.tsx
@@ -82,7 +82,7 @@ describe('tails', () => {
       content: [], isError: false, callView: null, resultView: null,
     }
     const props: ToolRowOwnerProps = {
-      callId: 'c5', toolName: 'todo_write', block: settled, openDetails: vi.fn(),
+      callId: 'c5', toolName: 'todo_write', block: settled, openFile: vi.fn(),
     }
     const view = render(<GenericToolCard {...props} />)
     // Settled ok state keeps the variant icon (sparkle) instead of a StateDot.
@@ -99,7 +99,7 @@ describe('tails', () => {
       phase: 'ready',
     })
     const props = (block: RunningToolCall | ToolResultNode) => ({
-      callId: 'c1', toolName: 'bash', block, openDetails: vi.fn(),
+      callId: 'c1', toolName: 'bash', block, openFile: vi.fn(),
       sessionId: sid, useSessions: bindSnapshotSelector(list),
     } as unknown as ToolRowProps)
 
diff --git a/packages/client/ui-conversation/tests/todo-panel.spec.tsx b/packages/client/ui-conversation/tests/todo-panel.spec.tsx
index 755c6020c7..8cf1f45f52 100644
--- a/packages/client/ui-conversation/tests/todo-panel.spec.tsx
+++ b/packages/client/ui-conversation/tests/todo-panel.spec.tsx
@@ -99,10 +99,10 @@ const resultNode = (argsRaw: string, over?: Partial<ToolResultNode>): ToolResult
   content: [], isError: false, callView: null, resultView: null, ...over,
 })
 
-function rowProps(block: unknown, openDetails = vi.fn()): ToolRowProps {
+function rowProps(block: unknown): ToolRowProps {
   return {
     callId: 'c1', toolName: 'todo_write', block,
-    openDetails,
+    openFile: vi.fn(),
     sessionId: 's1',
     useSessions: () => undefined,
   } as unknown as ToolRowProps
@@ -143,27 +143,10 @@ describe('TodoRow', () => {
     expect(screen.getByText('todo_write · not json')).toBeTruthy()
   })
 
-  it('falls back when parsed args carry no todos array, and click opens details', () => {
-    const openDetails = vi.fn()
-    render(<TodoRow {...rowProps(resultNode('{"other":1}'), openDetails)} />)
+  it('falls back when parsed args carry no todos array and stays non-interactive', () => {
+    render(<TodoRow {...rowProps(resultNode('{"other":1}'))} />)
     expect(screen.getByText('todo_write · {"other":1}')).toBeTruthy()
-    fireEvent.click(screen.getByText('更新任务清单'))
-    expect(openDetails).toHaveBeenCalledTimes(1)
-  })
-
-  it('opens details from the keyboard on Enter and Space, ignoring other keys', () => {
-    const openDetails = vi.fn()
-    render(<TodoRow {...rowProps(resultNode(ARGS), openDetails)} />)
-    const row = screen.getByRole('button')
-    expect(row.getAttribute('tabindex')).toBe('0')
-    fireEvent.keyDown(row, { key: 'Enter' })
-    fireEvent.keyDown(row, { key: ' ' })
-    expect(openDetails).toHaveBeenCalledTimes(2)
-    // Space must not also scroll the flow: the handler claims the event.
-    expect(fireEvent.keyDown(row, { key: ' ' })).toBe(false)
-    fireEvent.keyDown(row, { key: 'a' })
-    fireEvent.keyDown(row, { key: 'ArrowDown' })
-    expect(openDetails).toHaveBeenCalledTimes(3)
+    expect(screen.queryByRole('button')).toBeNull()
   })
 
   it.each([
diff --git a/packages/client/ui-conversation/tests/views-type-chain.spec.tsx b/packages/client/ui-conversation/tests/views-type-chain.spec.tsx
index 684a5fdb38..69e8355870 100644
--- a/packages/client/ui-conversation/tests/views-type-chain.spec.tsx
+++ b/packages/client/ui-conversation/tests/views-type-chain.spec.tsx
@@ -49,6 +49,8 @@ describe('view-ring type negatives (compile-time; body never runs)', () => {
       const chatProps = (props: ChatViewSlotProps): ReactNode => {
         // @ts-expect-error openDetails takes a SelectionTarget, not a string
         props.openDetails('nope')
+        // @ts-expect-error openFile takes a path string, not a SelectionTarget
+        props.openFile({ turnSeq: 1, callId: 'c' })
         return null
       }
       void chatProps
diff --git a/packages/host/apiproxy/README.i18n.yaml b/packages/host/apiproxy/README.i18n.yaml
index 78b8103d4c..182610325f 100644
--- a/packages/host/apiproxy/README.i18n.yaml
+++ b/packages/host/apiproxy/README.i18n.yaml
@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/host/apiproxy/README.md
-README.md: cd4ead7940cc056768aa40c997fbc46703e2cc85
-README.zh.md: c5ff0aefadbe746d2e948541652be5583028051d
+README.md: 6b4691164ceb82a68c94e5a71d2f44fcfa1634af
+README.zh.md: b28b57097a251ee18295a3f9a1ae41b00efe2db2
diff --git a/packages/host/apiproxy/README.md b/packages/host/apiproxy/README.md
index cd4ead7940..6b4691164c 100644
--- a/packages/host/apiproxy/README.md
+++ b/packages/host/apiproxy/README.md
@@ -20,7 +20,9 @@ Workspace and Session lists are separate reconnect baselines. `workspace.create`
 
 `host.pickDirectory` opens one native directory picker and returns its selected path, or `null` when the user cancels. Its host implementation invokes platform tools without a shell: `osascript` on macOS, an STA PowerShell `FolderBrowserDialog` on Windows, and Zenity with a KDialog fallback on Linux. The picker function is injectable for tests. This user-paced method is the sole unary call exempt from the default 30-second timeout; caller and connection aborts still propagate to the native process. The browser carrier separately restricts this privileged method to loopback, same-origin requests.
 
-`session.history` pages on message boundaries; its tail page (no `beforeSeq`) additionally carries the in-flight partial's chunk events. Session-level projections (todos included) ride the generic `projections` block above rather than per-domain rider fields.
+`host.openPath` opens a filesystem path with the operating system's default application (`open` on macOS, `Invoke-Item` on Windows, `xdg-open` on Linux). The opener is injectable for tests. The browser carrier applies the same loopback, same-origin restriction as `host.pickDirectory`.
+
+`session.history` pages on message boundaries, and its tail page (no `beforeSeq`) carries two session-level extras the page window cannot supply: the in-flight partial's chunk events, and `todos` — the latest `todo/write` whole-list projection over the full log. Older pages omit `todos` because the projection is session-level, not per-page; a tail response that omits it means the whole log holds no `todo/write`, so clients read the absent field as the empty plan rather than as unchanged state.
 
 The `command.*` and `skill.*` domains expose the host command registry and skill catalog to clients. Every method addresses one session's agent by `sessionId` (a served session always has an Agent; `command.*` resumes cold sessions through the same path as `session.*`, while `skill.list` resolves the project root from the session header without touching the Agent registry). `command.execute` runs a slash-command line host-side with pure admission semantics: the response reports whether the line resolved to a handler plus the minted lifecycle `commandId` when it did (correlating the acknowledgment with the flow node), while the outcome rides the durably logged `command/run`/`command/done` lifecycle pair broadcast on the mux stream; the carrier's request signal cancels the running handler. `host/commands-changed` is the catalog invalidation frame: clients refetch `command.list` instead of diffing.
 
diff --git a/packages/host/apiproxy/README.zh.md b/packages/host/apiproxy/README.zh.md
index c5ff0aefad..b28b57097a 100644
--- a/packages/host/apiproxy/README.zh.md
+++ b/packages/host/apiproxy/README.zh.md
@@ -20,7 +20,9 @@ Workspace 列表与 Session 列表是相互独立的重连基线。`workspace.cr
 
 `host.pickDirectory` 会打开一个原生目录选择器并返回选中的路径；用户取消时返回 `null`。宿主实现不经 shell 调用平台工具：macOS 使用 `osascript`，Windows 使用以 STA 模式运行的 PowerShell `FolderBrowserDialog`，Linux 使用 Zenity，并以 KDialog 作为回退。选择器函数可在测试中注入。该方法需等待用户完成操作，是唯一不受默认 30 秒超时限制的一元调用；调用方发出的中止信号和连接中止仍会传播至原生进程。浏览器载体另行将这一特权方法限制为仅接受来自回环地址的同源请求。
 
-`session.history` 按消息边界分页；其尾页（不带 `beforeSeq`）额外携带进行中局部消息的 chunk 事件。会话级投影（含 todos）走上文的通用 `projections` 块，不设按领域的搭载字段。
+`host.openPath` 会用操作系统的默认应用打开一个文件系统路径（macOS 为 `open`，Windows 为 `Invoke-Item`，Linux 为 `xdg-open`）。打开器可在测试中注入。浏览器载体对其施加与 `host.pickDirectory` 相同的回环、同源限制。
+
+`session.history` 按消息边界分页，其尾页（不带 `beforeSeq`）额外携带两项页窗口本身无法提供的会话级数据：进行中局部消息的 chunk 事件，以及 `todos`——整份日志上最后一次 `todo/write` 的整表投影。较早的页面不带 `todos`，因为该投影是会话级而非分页级的；尾页响应缺少该字段意味着整份日志中没有任何 `todo/write`，因此客户端要把缺失字段读作空计划，而不是读作「状态未变」。
 
 `command.*` 与 `skill.*` 领域向客户端暴露宿主命令注册表和技能目录。每个方法都通过 `sessionId` 寻址一个会话的 Agent（被服务的会话必有 Agent；`command.*` 经由与 `session.*` 相同的路径恢复冷会话，而 `skill.list` 从会话头解析项目根目录，不触碰 Agent 注册表）。`command.execute` 在宿主侧运行一条斜杠命令行，语义为纯准入：响应报告该行是否解析到处理器，并在解析到时回带铸造的生命周期 `commandId`（将本次确认与流节点关联）；结局经由持久落账并在 mux 流广播的 `command/run`/`command/done` 生命周期事件对承载；载体的请求信号可取消正在运行的处理器。`host/commands-changed` 是目录失效帧：客户端重新拉取 `command.list` 而不是做差分。
 
diff --git a/packages/host/apiproxy/src/api-proxy.ts b/packages/host/apiproxy/src/api-proxy.ts
index cd8f489545..f5ee198dfd 100644
--- a/packages/host/apiproxy/src/api-proxy.ts
+++ b/packages/host/apiproxy/src/api-proxy.ts
@@ -41,6 +41,7 @@ import type {
 } from '@deepseek-ai/dsh-user-interaction'
 import { UserInteractionError } from '@deepseek-ai/dsh-user-interaction'
 import { pickNativeDirectory } from './native-directory-picker.ts'
+import { openNativePath } from './native-path-opener.ts'
 
 /** Page size when history is called without maxMessages. */
 const DEFAULT_MAX_MESSAGES = 50
@@ -187,6 +188,8 @@ export interface ApiProxyDefaults {
   workspaceRoot: string
   /** Native single-directory picker; injectable for carrier tests. */
   pickDirectory?: (signal: AbortSignal) => Promise<string | null>
+  /** Native open-with-default-application; injectable for carrier tests. */
+  openPath?: (path: string, signal: AbortSignal) => Promise<void>
 }
 
 /** The tool/call payload fields the presenter path reads. */
@@ -1017,6 +1020,28 @@ export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiPro
           })
         }
       },
+
+      async openPath(request, signal) {
+        try {
+          const open = defaults.openPath
+            ?? ((path: string, openSignal: AbortSignal) => openNativePath(path, openSignal))
+          await open(request.payload.path, signal)
+          return ok(request, { opened: true as const })
+        } catch (error: unknown) {
+          if (signal.aborted) {
+            return err(request, {
+              code: 'cancelled',
+              message: 'path open was aborted',
+              details: {},
+            })
+          }
+          return err(request, {
+            code: 'internal',
+            message: `path open failed: ${error instanceof Error ? error.message : String(error)}`,
+            details: {},
+          })
+        }
+      },
     },
 
     commands: {
diff --git a/packages/host/apiproxy/src/api/host.schema.ts b/packages/host/apiproxy/src/api/host.schema.ts
index c7353c4360..e451c62100 100644
--- a/packages/host/apiproxy/src/api/host.schema.ts
+++ b/packages/host/apiproxy/src/api/host.schema.ts
@@ -25,3 +25,13 @@ export const hostPickDirectoryRequestSchema = z.object({}) satisfies z.ZodType<W
 export const hostPickDirectoryValueSchema = z.object({
   path: z.string().nullable(),
 }) satisfies z.ZodType<Wire<ResponseValue<'host.pickDirectory'>>>
+
+/** host.openPath request payload. */
+export const hostOpenPathRequestSchema = z.object({
+  path: z.string().min(1),
+}) satisfies z.ZodType<Wire<RequestPayload<'host.openPath'>>>
+
+/** host.openPath response value. */
+export const hostOpenPathValueSchema = z.object({
+  opened: z.literal(true),
+}) satisfies z.ZodType<Wire<ResponseValue<'host.openPath'>>>
diff --git a/packages/host/apiproxy/src/api/host.ts b/packages/host/apiproxy/src/api/host.ts
index e3573346f4..2e62c972ae 100644
--- a/packages/host/apiproxy/src/api/host.ts
+++ b/packages/host/apiproxy/src/api/host.ts
@@ -28,4 +28,14 @@ export interface HostApi {
     request: RpcRequest<{}>,
     signal: AbortSignal,
   ): Promise<RpcResponse<{ path: string | null }>>
+
+  /**
+   * Open a filesystem path with the operating system's default application
+   * (Finder / Explorer / xdg-open hand-off). The browser carrier restricts this
+   * privileged method to loopback, same-origin requests.
+   */
+  openPath(
+    request: RpcRequest<{ path: string }>,
+    signal: AbortSignal,
+  ): Promise<RpcResponse<{ opened: true }>>
 }
diff --git a/packages/host/apiproxy/src/api/rpc-map.ts b/packages/host/apiproxy/src/api/rpc-map.ts
index d98a7c01b3..7beabd2696 100644
--- a/packages/host/apiproxy/src/api/rpc-map.ts
+++ b/packages/host/apiproxy/src/api/rpc-map.ts
@@ -26,6 +26,7 @@ export interface RpcMethodMap {
   'session.cancel': SessionsApi['cancel']
   'host.describe': HostApi['describe']
   'host.pickDirectory': HostApi['pickDirectory']
+  'host.openPath': HostApi['openPath']
   'workspace.list': WorkspaceApi['list']
   'workspace.create': WorkspaceApi['create']
   'workspace.rename': WorkspaceApi['rename']
diff --git a/packages/host/apiproxy/src/fetch/client.ts b/packages/host/apiproxy/src/fetch/client.ts
index 62bef32b29..ceca9fee7e 100644
--- a/packages/host/apiproxy/src/fetch/client.ts
+++ b/packages/host/apiproxy/src/fetch/client.ts
@@ -13,7 +13,9 @@ import { RpcId } from '../api/rpc.ts'
 import type { Wire } from '../api/rpc.schema.ts'
 import { rpcReceiptSchema, serverRequestSchema, serverResponseSchema } from '../api/rpc.schema.ts'
 import { hostFrameSchema, muxFrameSchema } from '../api/events.schema.ts'
-import { hostDescribeValueSchema, hostPickDirectoryValueSchema } from '../api/host.schema.ts'
+import {
+  hostDescribeValueSchema, hostOpenPathValueSchema, hostPickDirectoryValueSchema,
+} from '../api/host.schema.ts'
 import {
   sessionCancelValueSchema,
   sessionCreateValueSchema,
@@ -61,6 +63,7 @@ export interface IApiClient {
   host: {
     describe(payload: RequestPayload<'host.describe'>, signal?: AbortSignal): Promise<RpcResponse<ResponseValue<'host.describe'>>>
     pickDirectory(payload: RequestPayload<'host.pickDirectory'>, signal?: AbortSignal): Promise<RpcResponse<ResponseValue<'host.pickDirectory'>>>
+    openPath(payload: RequestPayload<'host.openPath'>, signal?: AbortSignal): Promise<RpcResponse<ResponseValue<'host.openPath'>>>
   }
   workspace: {
     list(payload: RequestPayload<'workspace.list'>, signal?: AbortSignal): Promise<RpcResponse<ResponseValue<'workspace.list'>>>
@@ -98,6 +101,7 @@ const UNARY_VALUE_SCHEMAS: { [K in keyof RpcMethodMap]: z.ZodType<Wire<ResponseV
   'session.cancel': sessionCancelValueSchema,
   'host.describe': hostDescribeValueSchema,
   'host.pickDirectory': hostPickDirectoryValueSchema,
+  'host.openPath': hostOpenPathValueSchema,
   'workspace.list': workspaceListValueSchema,
   'workspace.create': workspaceCreateValueSchema,
   'workspace.rename': workspaceRenameValueSchema,
@@ -305,6 +309,7 @@ export abstract class AbstractApiClient implements IApiClient {
     // A native system dialog is user-paced and may legitimately stay open
     // longer than the normal unary deadline. Caller/connection aborts remain.
     pickDirectory: (payload, signal) => this.callUnary('host.pickDirectory', payload, signal, false),
+    openPath: (payload, signal) => this.callUnary('host.openPath', payload, signal),
   }
 
   readonly workspace: IApiClient['workspace'] = {
diff --git a/packages/host/apiproxy/src/fetch/handler.ts b/packages/host/apiproxy/src/fetch/handler.ts
index f0535dc939..505239c084 100644
--- a/packages/host/apiproxy/src/fetch/handler.ts
+++ b/packages/host/apiproxy/src/fetch/handler.ts
@@ -23,7 +23,9 @@ import {
   sessionPromptRequestSchema,
   sessionSelectModelRequestSchema,
 } from '../api/sessions.schema.ts'
-import { hostDescribeRequestSchema, hostPickDirectoryRequestSchema } from '../api/host.schema.ts'
+import {
+  hostDescribeRequestSchema, hostOpenPathRequestSchema, hostPickDirectoryRequestSchema,
+} from '../api/host.schema.ts'
 import {
   workspaceCreateRequestSchema,
   workspaceDeleteRequestSchema,
@@ -60,6 +62,7 @@ const UNARY_ROUTES: UnaryRoutes = {
   'session.cancel': { schema: sessionCancelRequestSchema, invoke: (api, r) => api.sessions.cancel(r) },
   'host.describe': { schema: hostDescribeRequestSchema, invoke: (api, r) => api.host.describe(r) },
   'host.pickDirectory': { schema: hostPickDirectoryRequestSchema, invoke: (api, r, signal) => api.host.pickDirectory(r, signal) },
+  'host.openPath': { schema: hostOpenPathRequestSchema, invoke: (api, r, signal) => api.host.openPath(r, signal) },
   'workspace.list': { schema: workspaceListRequestSchema, invoke: (api, r) => api.workspace.list(r) },
   'workspace.create': { schema: workspaceCreateRequestSchema, invoke: (api, r) => api.workspace.create(r) },
   'workspace.rename': { schema: workspaceRenameRequestSchema, invoke: (api, r) => api.workspace.rename(r) },
diff --git a/packages/host/apiproxy/src/native-command.ts b/packages/host/apiproxy/src/native-command.ts
new file mode 100644
index 0000000000..0efe9679d8
--- /dev/null
+++ b/packages/host/apiproxy/src/native-command.ts
@@ -0,0 +1,38 @@
+/** Shared no-shell `execFile` runner for native host dialogs and openers. */
+
+import { execFile } from 'node:child_process'
+
+/** Testable command boundary; native implementations never invoke a shell. */
+export type NativeCommandRunner = (
+  command: string,
+  args: readonly string[],
+  signal: AbortSignal,
+) => Promise<{ stdout: string; stderr: string }>
+
+/**
+ * Run a host command with utf8 stdio, abort propagation, and Windows hide.
+ * @param command - executable path or PATH name.
+ * @param args - argv (never a shell string).
+ * @param signal - caller/connection lifetime; abort terminates the child.
+ * @returns captured stdout/stderr on exit 0.
+ */
+export const runNativeCommand: NativeCommandRunner = (command, args, signal) =>
+  new Promise((resolve, reject) => {
+    execFile(
+      command,
+      [...args],
+      { encoding: 'utf8', signal, windowsHide: true },
+      (error, stdout, stderr) => {
+        if (error !== null) {
+          const failure = Object.assign(new Error(error.message, { cause: error }), {
+            code: error.code,
+            stdout,
+            stderr,
+          })
+          reject(failure)
+          return
+        }
+        resolve({ stdout, stderr })
+      },
+    )
+  })
diff --git a/packages/host/apiproxy/src/native-directory-picker.ts b/packages/host/apiproxy/src/native-directory-picker.ts
index 8bc0bc99ce..0ddba8e30d 100644
--- a/packages/host/apiproxy/src/native-directory-picker.ts
+++ b/packages/host/apiproxy/src/native-directory-picker.ts
@@ -1,13 +1,9 @@
 /** Cross-platform native single-directory picker used by the local GUI carrier. */
 
-import { execFile } from 'node:child_process'
+import { runNativeCommand, type NativeCommandRunner } from './native-command.ts'
 
 /** Testable command boundary; native implementations never invoke a shell. */
-export type DirectoryPickerRunner = (
-  command: string,
-  args: readonly string[],
-  signal: AbortSignal,
-) => Promise<{ stdout: string; stderr: string }>
+export type DirectoryPickerRunner = NativeCommandRunner
 
 /** Injectable platform facts for deterministic adapter tests. */
 export interface DirectoryPickerInternals {
@@ -15,27 +11,6 @@ export interface DirectoryPickerInternals {
   run?: DirectoryPickerRunner
 }
 
-const runCommand: DirectoryPickerRunner = (command, args, signal) =>
-  new Promise((resolve, reject) => {
-    execFile(
-      command,
-      [...args],
-      { encoding: 'utf8', signal, windowsHide: true },
-      (error, stdout, stderr) => {
-        if (error !== null) {
-          const failure = Object.assign(new Error(error.message, { cause: error }), {
-            code: error.code,
-            stdout,
-            stderr,
-          })
-          reject(failure)
-          return
-        }
-        resolve({ stdout, stderr })
-      },
-    )
-  })
-
 function outputPath(stdout: string): string | null {
   const path = stdout.replace(/[\r\n]+$/, '')
   return path === '' ? null : path
@@ -72,7 +47,7 @@ export async function pickNativeDirectory(
   internals: DirectoryPickerInternals = {},
 ): Promise<string | null> {
   const platform = internals.platform ?? process.platform
-  const run = internals.run ?? runCommand
+  const run = internals.run ?? runNativeCommand
 
   if (platform === 'darwin') {
     try {
diff --git a/packages/host/apiproxy/src/native-path-opener.ts b/packages/host/apiproxy/src/native-path-opener.ts
new file mode 100644
index 0000000000..15a6d7a73b
--- /dev/null
+++ b/packages/host/apiproxy/src/native-path-opener.ts
@@ -0,0 +1,53 @@
+/** Cross-platform open-with-default-application used by the local GUI carrier. */
+
+import { runNativeCommand, type NativeCommandRunner } from './native-command.ts'
+
+/** Testable command boundary; native implementations never invoke a shell. */
+export type PathOpenerRunner = NativeCommandRunner
+
+/** Injectable platform facts for deterministic adapter tests. */
+export interface PathOpenerInternals {
+  platform?: NodeJS.Platform
+  run?: PathOpenerRunner
+}
+
+/** PowerShell single-quoted literal (doubles embedded quotes). */
+function powershellLiteral(path: string): string {
+  return `'${path.replace(/'/g, "''")}'`
+}
+
+/**
+ * Open a filesystem path with the operating system's default application.
+ * @param path - absolute or host-resolvable path (caller owns resolution).
+ * @param signal - caller/connection lifetime; abort terminates the native command.
+ * @param internals - platform and runner seam for deterministic tests.
+ */
+export async function openNativePath(
+  path: string,
+  signal: AbortSignal,
+  internals: PathOpenerInternals = {},
+): Promise<void> {
+  const platform = internals.platform ?? process.platform
+  const run = internals.run ?? runNativeCommand
+
+  if (platform === 'darwin') {
+    await run('open', [path], signal)
+    return
+  }
+
+  if (platform === 'win32') {
+    await run('powershell.exe', [
+      '-NoProfile',
+      '-Command',
+      `Invoke-Item -LiteralPath ${powershellLiteral(path)}`,
+    ], signal)
+    return
+  }
+
+  if (platform === 'linux') {
+    await run('xdg-open', [path], signal)
+    return
+  }
+
+  throw new Error(`native path opener is unsupported on ${platform}`)
+}
diff --git a/packages/host/apiproxy/tests/api-proxy-workspace.spec.ts b/packages/host/apiproxy/tests/api-proxy-workspace.spec.ts
index c6354db928..bd0790b5c3 100644
--- a/packages/host/apiproxy/tests/api-proxy-workspace.spec.ts
+++ b/packages/host/apiproxy/tests/api-proxy-workspace.spec.ts
@@ -57,7 +57,10 @@ function stubAgent(session: Session): Agent {
 /** Compose the API over real Session, Agent, Storage, Domain, and Workspace services. */
 async function harness(
   workspaceRoot = realpathSync(mkdtempSync(join(tmpdir(), 'dsh-apiproxy-workspace-'))),
-  pickDirectory?: (signal: AbortSignal) => Promise<string | null>,
+  extras: {
+    pickDirectory?: (signal: AbortSignal) => Promise<string | null>
+    openPath?: (path: string, signal: AbortSignal) => Promise<void>
+  } = {},
 ) {
   const ctx = new Context()
   await ctx.plugin(SessionStore)
@@ -97,26 +100,29 @@ async function harness(
     model: 'test-model',
     cwd: workspaceRoot,
     workspaceRoot,
-    ...pickDirectory === undefined ? {} : { pickDirectory },
+    ...extras.pickDirectory === undefined ? {} : { pickDirectory: extras.pickDirectory },
+    ...extras.openPath === undefined ? {} : { openPath: extras.openPath },
   })
   return { api, ctx, storageDomain, workspaceRoot }
 }
 
 describe('host.pickDirectory', () => {
   it('returns a selected path or explicit cancellation from the injected native boundary', async () => {
-    const selected = await harness(undefined, async () => '/tmp/project')
+    const selected = await harness(undefined, { pickDirectory: async () => '/tmp/project' })
     expect((await selected.api.host.pickDirectory(request({}), new AbortController().signal)).result)
       .toEqual({ ok: true, value: { path: '/tmp/project' } })
 
-    const cancelled = await harness(undefined, async () => null)
+    const cancelled = await harness(undefined, { pickDirectory: async () => null })
     expect((await cancelled.api.host.pickDirectory(request({}), new AbortController().signal)).result)
       .toEqual({ ok: true, value: { path: null } })
   })
 
   it('propagates abort into the native boundary as a cancelled RPC error', async () => {
-    const { api } = await harness(undefined, signal => new Promise((_resolve, reject) => {
-      signal.addEventListener('abort', () => { reject(new Error('aborted')) }, { once: true })
-    }))
+    const { api } = await harness(undefined, {
+      pickDirectory: signal => new Promise((_resolve, reject) => {
+        signal.addEventListener('abort', () => { reject(new Error('aborted')) }, { once: true })
+      }),
+    })
     const abort = new AbortController()
     const pending = api.host.pickDirectory(request({}), abort.signal)
     abort.abort()
@@ -124,6 +130,30 @@ describe('host.pickDirectory', () => {
   })
 })
 
+describe('host.openPath', () => {
+  it('opens through the injected native boundary', async () => {
+    const opened: string[] = []
+    const { api } = await harness(undefined, {
+      openPath: async (path) => { opened.push(path) },
+    })
+    expect((await api.host.openPath(request({ path: '/tmp/a.txt' }), new AbortController().signal)).result)
+      .toEqual({ ok: true, value: { opened: true } })
+    expect(opened).toEqual(['/tmp/a.txt'])
+  })
+
+  it('propagates abort into the native boundary as a cancelled RPC error', async () => {
+    const { api } = await harness(undefined, {
+      openPath: (_path, signal) => new Promise((_resolve, reject) => {
+        signal.addEventListener('abort', () => { reject(new Error('aborted')) }, { once: true })
+      }),
+    })
+    const abort = new AbortController()
+    const pending = api.host.openPath(request({ path: '/tmp/a.txt' }), abort.signal)
+    abort.abort()
+    expect((await pending).result).toMatchObject({ ok: false, error: { code: 'cancelled' } })
+  })
+})
+
 describe('workspace.create', () => {
   it('serializes concurrent names and rejects the duplicate', async () => {
     const { api, workspaceRoot } = await harness()
diff --git a/packages/host/apiproxy/tests/client-handler.spec.ts b/packages/host/apiproxy/tests/client-handler.spec.ts
index 2dbc962a00..2794aa13d2 100644
--- a/packages/host/apiproxy/tests/client-handler.spec.ts
+++ b/packages/host/apiproxy/tests/client-handler.spec.ts
@@ -50,6 +50,7 @@ function scriptedApi(overrides: {
     host: {
       describe: r => ok(r, { version: '0-test', cwd: '/t', attachedSessions: 0 }),
       pickDirectory: r => ok(r, { path: null }),
+      openPath: r => ok(r, { opened: true as const }),
       ...overrides.host,
     },
     workspace: {
diff --git a/packages/host/apiproxy/tests/fetch-carrier.spec.ts b/packages/host/apiproxy/tests/fetch-carrier.spec.ts
index 971cce00ae..6c62501c60 100644
--- a/packages/host/apiproxy/tests/fetch-carrier.spec.ts
+++ b/packages/host/apiproxy/tests/fetch-carrier.spec.ts
@@ -81,6 +81,9 @@ function fakeApi(overrides: Partial<{ muxFrames: MuxFrame[]; hostFrames: HostFra
       async pickDirectory(request) {
         return { rpcId: request.rpcId, result: { ok: true, value: { path: null } } }
       },
+      async openPath(request) {
+        return { rpcId: request.rpcId, result: { ok: true, value: { opened: true as const } } }
+      },
     },
     workspace: {
       async list(request) {
@@ -210,6 +213,18 @@ describe('unary round trip (handler ⇄ client, no network)', () => {
     expect(response.result).toEqual({ ok: true, value: { path: '/tmp/project' } })
   })
 
+  it('round-trips host.openPath through the wire form', async () => {
+    const api = fakeApi()
+    let opened: string | undefined
+    api.host.openPath = async (request) => {
+      opened = request.payload.path
+      return { rpcId: request.rpcId, result: { ok: true, value: { opened: true as const } } }
+    }
+    const response = await client(api).host.openPath({ path: '/tmp/a.txt' })
+    expect(opened).toBe('/tmp/a.txt')
+    expect(response.result).toEqual({ ok: true, value: { opened: true } })
+  })
+
   it('round-trips command.list / command.execute / skill.list through the wire form', async () => {
     const c = client()
     const list = await c.commands.list({ sessionId: 's' as never })
diff --git a/packages/host/apiproxy/tests/native-path-opener.spec.ts b/packages/host/apiproxy/tests/native-path-opener.spec.ts
new file mode 100644
index 0000000000..c8622002e2
--- /dev/null
+++ b/packages/host/apiproxy/tests/native-path-opener.spec.ts
@@ -0,0 +1,82 @@
+type ExecFileCallback = (
+  error: (Error & { code?: string | number }) | null,
+  stdout: string,
+  stderr: string,
+) => void
+type ExecFileMock = (
+  command: string,
+  args: readonly string[],
+  options: { encoding: string; signal: AbortSignal; windowsHide: boolean },
+  callback: ExecFileCallback,
+) => void
+
+const { execFileMock } = vi.hoisted(() => ({ execFileMock: vi.fn<ExecFileMock>() }))
+
+vi.mock('node:child_process', () => ({ execFile: execFileMock }))
+
+import { describe, expect, it, vi } from 'vitest'
+import { openNativePath, type PathOpenerRunner } from '../src/native-path-opener.ts'
+
+const signal = () => new AbortController().signal
+
+describe('native path opener', () => {
+  it('opens with macOS open(1)', async () => {
+    const run = vi.fn<PathOpenerRunner>(async () => ({ stdout: '', stderr: '' }))
+    await openNativePath('/Users/test/file.txt', signal(), { platform: 'darwin', run })
+    expect(run).toHaveBeenCalledWith('open', ['/Users/test/file.txt'], expect.any(AbortSignal))
+  })
+
+  it('opens with Windows Invoke-Item and escapes single quotes', async () => {
+    const run = vi.fn<PathOpenerRunner>(async () => ({ stdout: '', stderr: '' }))
+    await openNativePath("C:\\work\\o'reilly.txt", signal(), { platform: 'win32', run })
+    expect(run).toHaveBeenCalledWith(
+      'powershell.exe',
+      ['-NoProfile', '-Command', "Invoke-Item -LiteralPath 'C:\\work\\o''reilly.txt'"],
+      expect.any(AbortSignal),
+    )
+  })
+
+  it('opens with Linux xdg-open', async () => {
+    const run = vi.fn<PathOpenerRunner>(async () => ({ stdout: '', stderr: '' }))
+    await openNativePath('/tmp/a.txt', signal(), { platform: 'linux', run })
+    expect(run).toHaveBeenCalledWith('xdg-open', ['/tmp/a.txt'], expect.any(AbortSignal))
+  })
+
+  it('rejects unsupported platforms', async () => {
+    await expect(openNativePath('/x', signal(), { platform: 'freebsd' as NodeJS.Platform }))
+      .rejects.toThrow('unsupported on freebsd')
+  })
+
+  it('uses the current process platform when no platform override is supplied', async () => {
+    const run = vi.fn<PathOpenerRunner>(async () => ({ stdout: '', stderr: '' }))
+    await openNativePath('/tmp/platform-default.txt', signal(), { run })
+    const expected = process.platform === 'win32'
+      ? 'powershell.exe'
+      : process.platform === 'linux'
+        ? 'xdg-open'
+        : 'open'
+    expect(run.mock.calls[0]?.[0]).toBe(expected)
+  })
+
+  it('runs the default command adapter without a shell and preserves command failures', async () => {
+    execFileMock.mockImplementationOnce((_command, _args, _options, callback) => {
+      callback(null, '', '')
+    })
+    await openNativePath('/tmp/default.txt', signal(), { platform: 'darwin' })
+    const [command, args, options] = execFileMock.mock.calls[0]!
+    expect(command).toBe('open')
+    expect(args).toEqual(['/tmp/default.txt'])
+    expect(options.encoding).toBe('utf8')
+    expect(options.windowsHide).toBe(true)
+    expect(options.signal).toBeInstanceOf(AbortSignal)
+
+    const commandError = Object.assign(new Error('open failed'), { code: 1 })
+    execFileMock.mockImplementationOnce((_command, _args, _options, callback) => {
+      callback(commandError, 'partial output', 'failure details')
+    })
+    await expect(openNativePath('/tmp/missing.txt', signal(), { platform: 'darwin' })).rejects.toMatchObject({
+      message: 'open failed', cause: commandError, code: 1,
+      stdout: 'partial output', stderr: 'failure details',
+    })
+  })
+})
diff --git a/scripts/wine-windows-gates.sh b/scripts/wine-windows-gates.sh
index 8b6dcd8a0a..7706a88a4b 100755
--- a/scripts/wine-windows-gates.sh
+++ b/scripts/wine-windows-gates.sh
@@ -125,8 +125,26 @@ supportedArchitectures:
   os: [current, win32]
   cpu: [current, x64]
 EOF
-  (cd "$scratch/tree" && pnpm install --frozen-lockfile --ignore-scripts > "$scratch/logs/install.log" 2>&1) \
-    || { tail -40 "$scratch/logs/install.log" >&2; return 1; }
+  # The hoisted linker — used only by this lane — has an upstream rename
+  # race (pnpm/pnpm#12880): parallel linkers staging a nested package copy
+  # (observed on the tree's nested esbuild versions) rename their _tmp_*
+  # directory onto a path another racer already claimed, and the loser
+  # exits ERR_PNPM_ENOENT although an identical re-install succeeds.
+  # Exactly that signature earns up to two retries on a clean tree — the
+  # snapshot contains no node_modules, so wiping them restores the
+  # pre-install state; any other failure, or the race still standing after
+  # the final attempt, fails loud with the log tail.
+  local attempt
+  for attempt in 1 2 3; do
+    (cd "$scratch/tree" && pnpm install --frozen-lockfile --ignore-scripts > "$scratch/logs/install.log" 2>&1) \
+      && return 0
+    grep -q 'ERR_PNPM_ENOENT.*rename.*_tmp_' "$scratch/logs/install.log" || break
+    (( attempt < 3 )) || break
+    echo "wine-windows-gates: pnpm hoisted-linker rename race (pnpm/pnpm#12880) on install attempt $attempt; retrying on a clean tree" >&2
+    find "$scratch/tree" -name node_modules -type d -prune -exec rm -rf {} +
+  done
+  tail -40 "$scratch/logs/install.log" >&2
+  return 1
 }
 
 mkdir "$scratch/tree"