fix(agent): retry latest provider error

docs/feature-checklist.md

@@ -113,7 +113,7 @@ Flagship feature. C++ services + `dao://dao-agent` WebUI + vendor runtime.
 | ☐ | MCP exact-target eligibility and terminal lifecycle | `automation/dao_browser_target_policy.{h,cc}`, `mcp/dao_mcp_session_lifecycle_monitor.{h,cc}`, `dao_mcp_end_to_end_browsertest.cc`, `dao_mcp_service.{h,cc}` | 🔴 | Run `DaoMcpEndToEndBrowserTest.*` and the lifecycle filters in `DaoMcpServiceBrowserTest.*`; verify HTTP/HTTPS/literal blank/web-hosted PDF allow, popup/OTR/Guest/internal/extension/DevTools/Agent WebUI/file/data/custom rejection for execution without blocking catalog discovery, exact-owner `TARGET_GONE`, no tab fallback, pre-mutation forbidden switch rejection, Browser/Profile/target/navigation terminal cleanup, no Ready/Disabled status during enabled logical closing, and replacement admission only after the accepted socket disconnects |
 | ☐ | MCP startup, packaging, protocol, UI, and rebinding regression sweep | `browser_prefs_mcp.cc.patch`, `chrome_browser_main_extra_parts_profiles*.patch`, `chrome/BUILD_mcp_helper.gn.patch`, `mcp/`, `dao_mcp_approval_dialog.*`, `dao_mcp_control_banner_view.*`, Settings Dao page patches | 🔴 | After Chromium upgrades, verify Local State registration and clean startup/shutdown, owner-only Unix socket/metadata plus helper executable packaging, protocol framing/version/8 MiB and ingress/write bounds, DevTools attach/cancel/detach, approval and banner BrowserView layout, Settings switch/status/enabled-only quick setup/Copy/Stop, stable tab identity across reorder/restore/WebContents replacement, and complete target rebinding/cleanup |
 | ☐ | Agent page, selection, element-context, element-screenshot, and PDF-text attachments | `src/dao/.../agent/dao_chat_view.ts`, `dao_page_capture.ts`, `dao_agent_ui.cc` | — | Composer can attach current page, selected text, picked element DOM context, picked element screenshot, and PDF text without losing existing chips |
-| ☐ | Agent message actions and code-block insertion | `dao_chat_view.ts`, `dao_share_image.ts`, `dao_page_capture.ts` | — | Copy/share image/regenerate/edit/rewind work on the intended message; code-block insert appears only with a focused page input and inserts at cursor |
+| ☐ | Agent message actions, error retry, and code-block insertion | `dao_chat_view.ts`, `dao_share_image.ts`, `dao_page_capture.ts` | — | Copy/share image/regenerate/edit/rewind work on the intended message; the latest provider error can retry the original submission without duplicating its user message or changing earlier timeline entries, while cancelled and historical errors cannot retry; code-block insert appears only with a focused page input and inserts at cursor |
 | ☐ | SQLite `Statement::ColumnName()` accessor (agent memory DB) | `sql/statement.{cc,h}.patch` | 🟢 | `//sql` compiles; agent memory store links |
 | ☐ | Agent memory histogram variant | `tools/metrics/histograms/metadata/sql/histograms.xml.patch` | 🟢 | `validate_format.py` passes |
 | ☐ | Agent long-term memory store, memory context, and memory inspector | `src/dao/.../agent/dao_agent_memory_*`, `dao_memory_context.ts`, `dao_memory_app.ts`, `dao_memory_table.ts`, `dao_settings_view.ts` | — | Memory settings toggles persist; conversation/page context is saved and retrieved; `dao://memory` runs read-only SQL and clear/usage controls work |

docs/features.md

@@ -151,6 +151,10 @@ The stack includes: **LLM tool calling**, **long-term memory** (SQLite + FTS5),
 
 **Chat surface**
 - `dao_chat_view.ts` — Main conversation view (session resume, skill picker, dynamic chips, composer height tracking, cost stats / usage)
+- **Latest Agent error retry** — A terminal provider error exposes a retry
+  action that reuses the original user submission, replaces only its failed
+  assistant/tool branch, and preserves every earlier timeline entry; cancelled
+  and historical errors cannot truncate the conversation
 - `dao_chat_history_panel.ts` — History panel
 - `dao_compact.ts` — Conversation compaction for context management
 - `dao_page_capture.ts` — Convert current page to markdown and insert into the message

src/dao/browser/ui/webui/resources/agent/__tests__/dao_chat_view.test.ts

@@ -547,6 +547,28 @@ describe('dao-chat-view message metadata helpers', () => {
     expect(iface.requestUpdate).toHaveBeenCalled();
   });
 
+  it('does not auto-compact a latest provider error that can be retried',
+     async () => {
+    vi.mocked(estimateMessagesTokens).mockReturnValue(900);
+    const messages = [
+      {role: 'user', content: 'retry this prompt', dao: {id: 'u1'}},
+      {
+        role: 'assistant',
+        content: [{type: 'text', text: 'Partial response'}],
+        stopReason: 'error',
+        errorMessage: 'Provider unavailable',
+        dao: {id: 'e1'},
+      },
+    ];
+    const view = viewWithMessages(messages);
+    view.agent_.state.model = {contextWindow: 1000};
+
+    await view._daoTestMaybeAutoCompactAfterTurn();
+
+    expect(compactAgentMessages).not.toHaveBeenCalled();
+    expect(view.agent_.state.messages).toEqual(messages);
+  });
+
   it('stays silent when background auto-compaction fails', async () => {
     vi.mocked(estimateMessagesTokens).mockReturnValue(810);
     vi.mocked(compactAgentMessages).mockRejectedValue(
@@ -973,6 +995,106 @@ describe('dao-chat-view message metadata helpers', () => {
     expect(panel.querySelector('.dao-debug-context-menu-item')).toBeNull();
   });
 
+  it('shows retry only for the latest terminal agent error', () => {
+    const latestErrorView = viewWithMessages([
+      {role: 'user', content: 'keep this request', dao: {id: 'u1'}},
+      {
+        role: 'assistant',
+        content: [{type: 'text', text: 'Partial response before failure'}],
+        stopReason: 'error',
+        errorMessage: 'Network unavailable',
+        dao: {id: 'e1'},
+      },
+    ]);
+    const {panel: latestErrorPanel} = attachMessageHosts(latestErrorView);
+
+    latestErrorView._daoTestRefreshAssistantActions();
+
+    const retry = latestErrorPanel.querySelector(
+        '.dao-error-retry-btn') as HTMLButtonElement|null;
+    expect(retry).toBeTruthy();
+    expect(retry?.title).toBe('chat.message_actions.retry_error_tooltip');
+
+    const abortedView = viewWithMessages([
+      {role: 'user', content: 'cancel this request', dao: {id: 'u2'}},
+      {
+        role: 'assistant',
+        content: [{type: 'text', text: 'Partial response before cancel'}],
+        stopReason: 'aborted',
+        errorMessage: 'Request was aborted',
+        dao: {id: 'e2'},
+      },
+    ]);
+    const {panel: abortedPanel} = attachMessageHosts(abortedView);
+    abortedView._daoTestRefreshAssistantActions();
+    expect(abortedPanel.querySelector(
+        '.dao-assistant-actions[data-dao-message-id="e2"] .dao-retry-btn'))
+        .toBeNull();
+
+    const historicalErrorView = viewWithMessages([
+      {role: 'user', content: 'old request', dao: {id: 'u3'}},
+      {
+        role: 'assistant',
+        content: [{type: 'text', text: 'Partial old response'}],
+        stopReason: 'error',
+        errorMessage: 'Old failure',
+        dao: {id: 'e3'},
+      },
+      {role: 'user', content: 'new request', dao: {id: 'u4'}},
+      {role: 'assistant', content: 'new response', dao: {id: 'a4'}},
+    ]);
+    const {panel: historicalPanel} = attachMessageHosts(historicalErrorView);
+    historicalErrorView._daoTestRefreshAssistantActions();
+    expect(historicalPanel.querySelector(
+        '.dao-assistant-actions[data-dao-message-id="e3"] .dao-retry-btn'))
+        .toBeNull();
+  });
+
+  it('retries the failed submission without changing its earlier timeline',
+     async () => {
+       const view = viewWithMessages([
+         {role: 'user', content: 'earlier request', dao: {id: 'u0'}},
+         {role: 'assistant', content: 'earlier response', dao: {id: 'a0'}},
+         {
+           role: 'user-with-attachments',
+           content: 'retry this request',
+           attachments: [{id: 'page-1', extractedText: 'original context'}],
+           dao: {id: 'u1'},
+         },
+         {role: 'toolResult', content: 'partial tool output', dao: {id: 't1'}},
+         {
+           role: 'assistant',
+           content: [{type: 'text', text: ''}],
+           stopReason: 'error',
+           errorMessage: 'Provider failed',
+           dao: {id: 'e1'},
+         },
+       ]);
+       const {panel} = attachMessageHosts(view);
+       view._daoTestRefreshAssistantActions();
+
+       const retry = panel.querySelector(
+           '.dao-error-retry-btn') as HTMLButtonElement|null;
+       retry?.click();
+
+       await vi.waitFor(() => {
+         expect(view.agent_.continue).toHaveBeenCalledTimes(1);
+       });
+       expect(view.agent_.state.messages).toEqual([
+         {role: 'user', content: 'earlier request', dao: {id: 'u0'}},
+         {role: 'assistant', content: 'earlier response', dao: {id: 'a0'}},
+         {
+           role: 'user-with-attachments',
+           content: 'retry this request',
+           attachments: [{id: 'page-1', extractedText: 'original context'}],
+           dao: {id: 'u1'},
+         },
+       ]);
+       expect(view.agent_.state.messages.filter(
+           msg => msg.role === 'user' || msg.role === 'user-with-attachments'))
+           .toHaveLength(2);
+     });
+
   it('regenerates from the user paired with the selected assistant', async () => {
     const messages = selectedAssistantHistory();
     const view = viewWithMessages(messages);

src/dao/browser/ui/webui/resources/agent/dao_chat_view.ts

@@ -94,6 +94,7 @@ type DaoChatMessage = {
   model?: string;
   usage?: {input: number; output: number; cacheRead: number; cacheWrite: number};
   stopReason?: string;
+  errorMessage?: string;
 };
 
 interface DaoAssistantPair {
@@ -1851,6 +1852,29 @@ export class DaoChatView extends CrLitElement {
     return row;
   }
 
+  private buildErrorActionRow_(
+      msg: DaoChatMessage, disabled: boolean): HTMLElement {
+    const row = document.createElement('div');
+    row.className =
+        'dao-message-actions dao-assistant-actions dao-error-actions';
+    row.dataset['daoMessageId'] = msg.dao?.id || '';
+    const retrySvg =
+        '<svg viewBox="0 0 24 24" fill="none" stroke="currentColor"' +
+        ' stroke-width="2" stroke-linecap="round" stroke-linejoin="round"' +
+        ' aria-hidden="true">' +
+        '<path d="M3 12a9 9 0 1 0 3-6.7"></path>' +
+        '<path d="M3 4v5h5"></path>' +
+        '</svg>';
+    const id = msg.dao?.id || '';
+    const retry = this.buildActionButton_(
+        'dao-retry-btn dao-error-retry-btn',
+        'chat.message_actions.retry_error_tooltip', retrySvg,
+        () => void this.retryErrorById_(id));
+    retry.disabled = disabled;
+    row.appendChild(retry);
+    return row;
+  }
+
   private buildUserActionRow_(
       msg: DaoChatMessage, disabled: boolean): HTMLElement {
     const row = document.createElement('div');
@@ -2226,7 +2250,13 @@ export class DaoChatView extends CrLitElement {
         }
       } else if (role === 'assistant') {
         const el = assistantEls[assistantCursor++] as HTMLElement | undefined;
-        if (el && msg.dao?.id && this.isAssistantMessage_(msg)) {
+        if (el && msg.dao?.id && msg === msgs[msgs.length - 1] &&
+            this.isRetryableAssistantError_(msg)) {
+          el.insertAdjacentElement(
+              'afterend', this.buildErrorActionRow_(msg, disabled));
+        } else if (el && msg.dao?.id &&
+                   !this.isTerminalAssistantFailure_(msg) &&
+                   this.isAssistantMessage_(msg)) {
           const idx = msgs.indexOf(msg);
           const canRewind = idx >= 0 && idx !== latestAssistantIdx;
           el.insertAdjacentElement(
@@ -2435,6 +2465,17 @@ export class DaoChatView extends CrLitElement {
     await this.retryFromUserIndex_(userIdx);
   }
 
+  private async retryErrorById_(errorId: string): Promise<void> {
+    const errorIdx = this.findMessageIndexByDaoId_(errorId);
+    const messages = this.currentMessages_();
+    if (errorIdx !== messages.length - 1 ||
+        !this.isRetryableAssistantError_(messages[errorIdx])) {
+      return;
+    }
+    await this.retryFromUserIndex_(
+        this.findUserIndexForAssistantIndex_(errorIdx));
+  }
+
   private async rewindToAssistantById_(assistantId: string): Promise<void> {
     const agent = this.agent_;
     if (!agent || agent.state.isStreaming || this.isStreaming_) return;
@@ -3484,6 +3525,18 @@ export class DaoChatView extends CrLitElement {
         !!this.extractVisibleText_(msg as DaoChatMessage);
   }
 
+  private isRetryableAssistantError_(msg: unknown): msg is DaoChatMessage {
+    return isRecord(msg) && msg['role'] === 'assistant' &&
+        msg['stopReason'] === 'error' &&
+        typeof msg['errorMessage'] === 'string' &&
+        !!msg['errorMessage'].trim();
+  }
+
+  private isTerminalAssistantFailure_(msg: unknown): boolean {
+    return isRecord(msg) && msg['role'] === 'assistant' &&
+        (msg['stopReason'] === 'error' || msg['stopReason'] === 'aborted');
+  }
+
   private extractVisibleText_(msg: DaoChatMessage): string {
     return this.extractAssistantText_(msg);
   }
@@ -3616,6 +3669,10 @@ export class DaoChatView extends CrLitElement {
     const msgs = this.currentMessages_().filter(
         msg => !this.isDaoLocalMessage_(msg));
     if (msgs.length < 2) return;
+    // Preserve the original submission and its terminal error until the user
+    // can retry it. Compaction may summarize that user message and appends a
+    // local notice after the error, either of which would invalidate retry.
+    if (this.isRetryableAssistantError_(msgs[msgs.length - 1])) return;
     const tokens = estimateMessagesTokens(
         msgs as unknown as Parameters<typeof estimateMessagesTokens>[0]);
     const ratio = tokens / ctx;

src/dao/browser/ui/webui/resources/agent/i18n/locales/en.ts

@@ -130,6 +130,7 @@ const dict: Dictionary = {
   'chat.message_actions.copy_tooltip': 'Copy answer text',
   'chat.message_actions.share_tooltip': 'Copy as image',
   'chat.message_actions.regenerate_tooltip': 'Regenerate response',
+  'chat.message_actions.retry_error_tooltip': 'Retry request',
   'chat.message_actions.rewind_tooltip': 'Rewind to this response',
   'chat.message_actions.more_tooltip': 'More actions',
   'chat.message_actions.edit': 'Edit',

src/dao/browser/ui/webui/resources/agent/i18n/locales/zh-CN.ts

@@ -100,6 +100,7 @@ const dict: Dictionary = {
   'chat.message_actions.copy_tooltip': '复制回答文本',
   'chat.message_actions.share_tooltip': '复制为图片',
   'chat.message_actions.regenerate_tooltip': '重新生成回答',
+  'chat.message_actions.retry_error_tooltip': '重试请求',
   'chat.message_actions.rewind_tooltip': '回到这条回答',
   'chat.message_actions.more_tooltip': '更多操作',
   'chat.message_actions.edit': '编辑',