fix(runtime): bound malformed compaction retries

apps/desktop/src/main/__tests__/session-error-presentation.test.ts

@@ -21,6 +21,7 @@ import assert from 'node:assert/strict';
 import { describe, it } from 'node:test';
 
 import { describeSessionErrorReason } from '../../renderer/session-error-presentation.js';
+import { sessionEventErrorMessage } from '../../renderer/model-connection-errors.js';
 import { deriveFailedTurnRecovery, describeTurnErrorClass } from '../../renderer/session-status-presentation.js';
 
 describe('provider capacity presentation', () => {
@@ -41,3 +42,21 @@ describe('provider capacity presentation', () => {
     assert.doesNotMatch(recovery.label, /直接重试/);
   });
 });
+
+describe('context compaction failure presentation', () => {
+  it('shows actionable malformed-summary guidance', () => {
+    const message = sessionEventErrorMessage({
+      type: 'error',
+      id: 'error-1',
+      turnId: 'turn-1',
+      ts: 1,
+      recoverable: false,
+      reason: 'context_budget_exhausted',
+      message: 'Turn failed: context_budget_exhausted',
+      details: { contextBudgetExhaustedDetail: 'malformed_summary_missing_section' },
+    });
+
+    assert.match(message, /上下文压缩/);
+    assert.match(message, /上下文窗口设置|切换模型|开启新任务/);
+  });
+});

apps/desktop/src/main/__tests__/session-status-presentation.test.ts

@@ -50,6 +50,19 @@ describe('failed turn recovery presentation', () => {
     );
   });
 
+  it('offers configuration or task recovery after runtime context exhaustion', () => {
+    assert.deepEqual(
+      deriveFailedTurnRecovery(
+        { ...outputFreeFailure, errorClass: 'context_budget_exhausted' },
+        'zh',
+      ),
+      {
+        action: 'check_connection',
+        label: '检查模型的上下文窗口设置、切换模型，或开启新任务',
+      },
+    );
+  });
+
   it('keeps the generic retry fallback for an unknown output-free failure', () => {
     assert.deepEqual(
       deriveFailedTurnRecovery({ ...outputFreeFailure, errorClass: 'unknown_failure' }, 'en'),

apps/desktop/src/renderer/locales/conversation-copy.ts

@@ -327,6 +327,8 @@ export interface DesktopConversationCopy {
   turnError: {
     unknown: string;
     contextOverflow: string;
+    contextBudgetExhausted: string;
+    malformedSummary: string;
     timeout: string;
     auth: string;
     providerBilling: string;
@@ -339,7 +341,7 @@ export interface DesktopConversationCopy {
     permission: string;
     restarted: string;
     sandboxBoundaryClosed: string;
-    recovery: Record<'safeResume' | 'stepCap' | 'toolError' | 'connection' | 'partial' | 'toolRecord' | 'retry' | 'capacity' | 'contextOverflow' | 'sandboxBoundaryClosed', string>;
+    recovery: Record<'safeResume' | 'stepCap' | 'toolError' | 'connection' | 'partial' | 'toolRecord' | 'retry' | 'capacity' | 'contextOverflow' | 'contextBudgetExhausted' | 'sandboxBoundaryClosed', string>;
   };
 }
 
@@ -636,7 +638,7 @@ const COPY = {
       reauth: { label: '上次连接测试鉴权失败', tooltip: '最近一次连接测试返回鉴权失败（401 / 403），密钥可能已过期或被吊销。这不会拦截发送，但若发送失败请到 设置 · 模型 重新登录。' },
       testError: { label: '上次连接测试失败', tooltip: '最近一次连接测试因网络 / 超时 / 5xx 失败。这不会拦截发送，但若问题持续请到 设置 · 模型 检查 Base URL / 代理。' },
     },
-    turnError: { unknown: '未知错误', contextOverflow: '上下文窗口已超出限制', timeout: '请求超时', auth: '鉴权失败', providerBilling: '模型服务计费受限', providerCapacity: '模型服务暂时满载，请稍后重试或切换模型', rateLimit: '触发模型速率限制', network: '网络错误', provider: '模型服务返回错误', stepCap: '达到工具步骤上限', tool: '工具调用失败', permission: '等待权限确认', restarted: '本地应用重启，上一轮没有完成', sandboxBoundaryClosed: '本地应用重启，等待确认的「允许访问工作区以外的内容」请求已按拒绝关闭', recovery: { safeResume: '检查当前状态后，可尝试安全恢复', stepCap: '任务可能尚未完成，可以继续', toolError: '先检查工具结果，再决定是否重试', connection: '先检查模型连接或登录状态', partial: '已保留部分输出，可从这里继续', toolRecord: '工具记录已保留，重试前先看结果', retry: '没有执行工具，可直接重试', capacity: '模型服务暂时满载，请等待几分钟或切换模型后重试', contextOverflow: '上下文仍超出限制，请减少附件或开启新任务', sandboxBoundaryClosed: '访问范围没有放开，重试本轮后可重新决定' } },
+    turnError: { unknown: '未知错误', contextOverflow: '上下文窗口已超出限制', contextBudgetExhausted: '上下文已达到上限，当前任务无法继续', malformedSummary: '上下文压缩未能生成有效摘要。请检查模型的上下文窗口设置、切换模型，或开启新任务。', timeout: '请求超时', auth: '鉴权失败', providerBilling: '模型服务计费受限', providerCapacity: '模型服务暂时满载，请稍后重试或切换模型', rateLimit: '触发模型速率限制', network: '网络错误', provider: '模型服务返回错误', stepCap: '达到工具步骤上限', tool: '工具调用失败', permission: '等待权限确认', restarted: '本地应用重启，上一轮没有完成', sandboxBoundaryClosed: '本地应用重启，等待确认的「允许访问工作区以外的内容」请求已按拒绝关闭', recovery: { safeResume: '检查当前状态后，可尝试安全恢复', stepCap: '任务可能尚未完成，可以继续', toolError: '先检查工具结果，再决定是否重试', connection: '先检查模型连接或登录状态', partial: '已保留部分输出，可从这里继续', toolRecord: '工具记录已保留，重试前先看结果', retry: '没有执行工具，可直接重试', capacity: '模型服务暂时满载，请等待几分钟或切换模型后重试', contextOverflow: '上下文仍超出限制，请减少附件或开启新任务', contextBudgetExhausted: '检查模型的上下文窗口设置、切换模型，或开启新任务', sandboxBoundaryClosed: '访问范围没有放开，重试本轮后可重新决定' } },
   },
   en: {
     actions: { stopFailedTitle: 'Failed to stop', stopFailedFallback: 'The task action failed. Try again later.', refreshSessionsFailedTitle: 'Failed to refresh tasks', refreshSessionsFailedFallback: 'The task list could not be refreshed. Try again later.', conversationErrorTitle: 'Task error', conversationErrorFallback: 'The task run failed. Try again later.', regenerateStartedTitle: 'Regeneration started', regenerateStartedDescription: 'Generating a new response', branchCreatedTitle: 'Branch created', branchCreatedDescription: (name) => `New task: ${name}`, revisionStartedTitle: 'Edit draft ready', revisionStartedDescription: 'The original task is kept; sending creates a new version', revisionReadyTitle: 'Ready to edit and resend', revisionReadyDescription: 'Rewound to before that message; edit and send when ready', revisionUnavailableTitle: 'This message cannot be edited yet', revisionAttachmentsUnsupported: 'Edit & resend does not yet support historical attachments. Copy the text into a new message instead.', revisionTransformedTextUnsupported: 'Edit & resend does not yet support messages sent with an explicit skill. Copy the text and select the skill again instead.', revisionDraftAttachmentConflict: 'The composer already has pending attachments. Send or remove them before editing a sent message.', revisionCommandUnsupported: 'You cannot run /compact, /side, or orchestration commands while editing a sent message. Cancel the edit first.', revisionAlreadyActive: 'Another message is already being edited. Send or cancel that edit first.', revisionCancelLabel: 'Cancel', revisionBannerTitle: 'Editing sent message', revisionBannerDetail: '· New version on send', revisionUnchanged: 'Nothing changed. Use Regenerate if you only want a new answer.', operationFailedTitle: 'Action failed', operationFailedFallback: 'The task action failed. Try again later.', attachmentFailedTitle: 'Failed to add attachment', tryAgain: 'Try again later.', modelReboundTitle: 'Switched to an available model', modelReboundDescription: (modelId) => `The previous connection is unavailable${modelId ? ` · ${modelId}` : ''}`, messageReadFailedTitle: 'Failed to load task', returnLatest: 'Return to latest', scrollMainToBottom: 'Scroll main conversation to bottom' },
@@ -867,7 +869,7 @@ const COPY = {
       reauth: { label: 'Last connection test failed authentication', tooltip: 'The latest test returned 401 / 403. Sending is not blocked, but sign in again under Settings · Models if it fails.' },
       testError: { label: 'Last connection test failed', tooltip: 'The latest test failed because of a network, timeout, or 5xx error. Sending is not blocked; check Base URL or proxy settings if it persists.' },
     },
-    turnError: { unknown: 'Unknown error', contextOverflow: 'Context window exceeded', timeout: 'Request timed out', auth: 'Authentication failed', providerBilling: 'Provider billing required', providerCapacity: 'The model service is temporarily at capacity. Wait and retry, or switch models.', rateLimit: 'Model rate limit reached', network: 'Network error', provider: 'Model service error', stepCap: 'Tool-step limit reached', tool: 'Tool call failed', permission: 'Waiting for permission', restarted: 'The app restarted before the previous turn completed', sandboxBoundaryClosed: 'The app restarted, so the pending request to reach outside the workspace was closed as denied', recovery: { safeResume: 'Inspect the current state, then try safe recovery', stepCap: 'The task may be incomplete; continue from here', toolError: 'Inspect the tool result before retrying', connection: 'Check the model connection or sign-in status', partial: 'Partial output was retained; continue from here', toolRecord: 'Tool history was retained; inspect it before retrying', retry: 'No tools ran; retry directly', capacity: 'The model service is at capacity. Wait a few minutes or switch models before retrying.', contextOverflow: 'Context is still too large; reduce attachments or start a new task', sandboxBoundaryClosed: 'Access was not widened; retry the turn to decide again' } },
+    turnError: { unknown: 'Unknown error', contextOverflow: 'Context window exceeded', contextBudgetExhausted: 'The context limit was reached and this task cannot continue', malformedSummary: 'Context compaction could not produce a valid summary. Check the model context-window setting, switch models, or start a new task.', timeout: 'Request timed out', auth: 'Authentication failed', providerBilling: 'Provider billing required', providerCapacity: 'The model service is temporarily at capacity. Wait and retry, or switch models.', rateLimit: 'Model rate limit reached', network: 'Network error', provider: 'Model service error', stepCap: 'Tool-step limit reached', tool: 'Tool call failed', permission: 'Waiting for permission', restarted: 'The app restarted before the previous turn completed', sandboxBoundaryClosed: 'The app restarted, so the pending request to reach outside the workspace was closed as denied', recovery: { safeResume: 'Inspect the current state, then try safe recovery', stepCap: 'The task may be incomplete; continue from here', toolError: 'Inspect the tool result before retrying', connection: 'Check the model connection or sign-in status', partial: 'Partial output was retained; continue from here', toolRecord: 'Tool history was retained; inspect it before retrying', retry: 'No tools ran; retry directly', capacity: 'The model service is at capacity. Wait a few minutes or switch models before retrying.', contextOverflow: 'Context is still too large; reduce attachments or start a new task', contextBudgetExhausted: 'Check the model context-window setting, switch models, or start a new task', sandboxBoundaryClosed: 'Access was not widened; retry the turn to decide again' } },
   },
 } satisfies UiCatalog<DesktopConversationCopy>;
 

apps/desktop/src/renderer/model-connection-errors.ts

@@ -60,6 +60,13 @@ export function sessionEventErrorMessage(
   if (isNoRealConnectionEvent(event)) {
     return noRealConnectionSetupDescription(noRealConnectionReasonFromEvent(event), locale);
   }
+  const contextBudgetDetail =
+    event.details && !Array.isArray(event.details)
+      ? event.details.contextBudgetExhaustedDetail
+      : undefined;
+  if (typeof contextBudgetDetail === 'string' && contextBudgetDetail.startsWith('malformed_summary_')) {
+    return getDesktopConversationCopy(locale).turnError.malformedSummary;
+  }
   const reasonDescription = describeSessionErrorReason(event.reason, locale);
   if (reasonDescription) return reasonDescription;
   const fallback = getDesktopConversationCopy(locale).actions.conversationErrorFallback;

apps/desktop/src/renderer/session-error-presentation.ts

@@ -30,6 +30,8 @@ export function describeSessionErrorReason(reason: string | undefined, locale: U
   switch (reason?.toLowerCase()) {
     case 'context_overflow':
       return copy.contextOverflow;
+    case 'context_budget_exhausted':
+      return copy.contextBudgetExhausted;
     case 'timeout':
       return copy.timeout;
     case 'auth':

apps/desktop/src/renderer/session-status-presentation.ts

@@ -180,5 +180,8 @@ export function deriveFailedTurnRecovery(input: FailedTurnRecoveryInput, locale:
   if (lower === 'context_overflow') {
     return { action: 'continue', label: copy.contextOverflow };
   }
+  if (lower === 'context_budget_exhausted') {
+    return { action: 'check_connection', label: copy.contextBudgetExhausted };
+  }
   return { action: 'retry', label: copy.retry };
 }

packages/core/src/events.ts

@@ -1205,6 +1205,9 @@ export type ContextCompactionOutcome =
 export type ContextBudgetExhaustedDetail =
   | 'no_safe_completed_span'
   | 'summarizer_failed'
+  | 'malformed_summary_missing_section'
+  | 'malformed_summary_truncated'
+  | 'malformed_summary_too_small_for_fold'
   | 'head_anchor_exceeds_capacity';
 
 export type CompleteStopReason = CompleteEvent['stopReason'];

packages/runtime-host/src/__tests__/canonical-session-projection.test.ts

@@ -421,6 +421,65 @@ test('projects a failed Turn message from the canonical terminal event', async (
   });
 });
 
+test('projects context-budget exhaustion detail from the canonical terminal event', async () => {
+  await withStores(async (root, stores) => {
+    const { sessionId, rootAdmissions } = await createRunningRoot(root, stores);
+    const context = {
+      sessionId,
+      invocationId: 'run-1',
+      runId: 'run-1',
+      turnId: 'turn-1',
+      source: 'test',
+      startedAt: 10,
+      request: {
+        sessionId,
+        invocationId: 'run-1',
+        runId: 'run-1',
+        turnId: 'turn-1',
+        text: 'hello',
+        source: 'test',
+      },
+      newId: () => 'unused',
+      now: () => 12,
+    } as const;
+    const terminalEvent = mapSessionEventToRuntimeEvent(
+      {
+        type: 'complete',
+        id: 'terminal-context-budget-1',
+        turnId: 'turn-1',
+        ts: 13,
+        stopReason: 'context_budget_exhausted',
+        contextBudgetExhaustedDetail: 'malformed_summary_missing_section',
+      },
+      context,
+      createSessionEventMapMemory(),
+    );
+    await stores.runtimeEventStore.appendRuntimeEvent(sessionId, 'run-1', terminalEvent);
+    await stores.agentRunStore.updateRun(sessionId, 'run-1', {
+      status: 'failed',
+      updatedAt: 13,
+      completedAt: 13,
+      failureClass: 'context_budget_exhausted',
+    });
+
+    const reader = new CanonicalSessionProjectionReader({
+      stores,
+      rootAdmissions,
+      messages: {
+        projection: () => ({ hostEpoch: 'epoch-1', queueRevision: 0, steering: [], followup: [] }),
+      },
+    });
+    const canonical = await reader.read(sessionId);
+    assert.equal(canonical?.rootTurn?.status, 'failed');
+    if (canonical?.rootTurn?.status === 'failed') {
+      assert.equal(
+        canonical.rootTurn.contextBudgetExhaustedDetail,
+        'malformed_summary_missing_section',
+      );
+    }
+  });
+});
+
 test('propagates canonical Store read failures during candidate preflight', async () => {
   await withStores(async (root, stores) => {
     const session = await stores.sessionStore.create(sessionInput(root));

packages/runtime-host/src/__tests__/protocol.test.ts

@@ -189,6 +189,13 @@ describe('Runtime Host bootstrap protocol', () => {
     assert.ok(RUNTIME_HOST_COMPATIBILITY_EPOCH > 47);
   });
 
+  test('publishes a new compatibility epoch for context-budget failure detail', () => {
+    // Epoch 50 is already used by WorkHub coordination summaries on main.
+    // The context-budget detail therefore needs its own strictly newer
+    // handshake boundary so peers cannot accept the wrong closed shape.
+    assert.ok(RUNTIME_HOST_COMPATIBILITY_EPOCH > 50);
+  });
+
   test('adds credential rotation without changing existing credential inputs', () => {
     const issueInput = {
       principalKind: 'remote_owner',
@@ -1607,6 +1614,15 @@ describe('Runtime Host bootstrap protocol', () => {
     };
 
     assert.deepEqual(decodeHostFrame(response), response);
+    const withContextDetail = {
+      ...response,
+      result: {
+        ...response.result,
+        failureClass: 'context_budget_exhausted',
+        contextBudgetExhaustedDetail: 'malformed_summary_missing_section' as const,
+      },
+    };
+    assert.deepEqual(decodeHostFrame(withContextDetail), withContextDetail);
     assert.throws(
       () =>
         decodeHostFrame({

packages/runtime-host/src/__tests__/session-projector.test.ts

@@ -269,6 +269,46 @@ test('reseeds the latest provider retry when the active Turn still carries one',
   assert.equal(seeded[0] && 'phase' in seeded[0] ? seeded[0].phase : undefined, 'scheduled');
 });
 
+test('projects structured context-budget failure detail to the Desktop event', () => {
+  const projector = new RuntimeHostSessionProjector(
+    snapshot(),
+    createRuntimeHostSessionProjectionSeed([], snapshot()),
+    () => 10,
+  );
+
+  const events = projector.accept({
+    kind: 'subscription.session_projection',
+    hostEpoch: 'host-1',
+    subscriptionId: 'subscription-1',
+    sequence: 1,
+    snapshot: snapshot({
+      projectionRevision: 2,
+      rootTurn: {
+        sessionId: 'session-1',
+        turnId: 'turn-1',
+        runId: 'run-1',
+        status: 'failed',
+        terminalEventId: 'terminal-1',
+        failureClass: 'context_budget_exhausted',
+        contextBudgetExhaustedDetail: 'malformed_summary_missing_section',
+      },
+    }),
+  }).events;
+
+  assert.deepEqual(events, [
+    {
+      type: 'error',
+      id: 'terminal-1',
+      turnId: 'turn-1',
+      ts: 10,
+      recoverable: false,
+      reason: 'context_budget_exhausted',
+      message: 'Turn failed: context_budget_exhausted',
+      details: { contextBudgetExhaustedDetail: 'malformed_summary_missing_section' },
+    },
+  ]);
+});
+
 test('emits a live provider retry when the snapshot overlay appears, then drops it after content', () => {
   const projector = new RuntimeHostSessionProjector(
     snapshot(),

packages/runtime-host/src/adapter/session-projector.ts

@@ -456,6 +456,9 @@ export class RuntimeHostSessionProjector {
         recoverable: false,
         reason: root.failureClass,
         message: root.failureMessage ?? `Turn failed: ${root.failureClass}`,
+        ...(root.contextBudgetExhaustedDetail
+          ? { details: { contextBudgetExhaustedDetail: root.contextBudgetExhaustedDetail } }
+          : {}),
       });
     } else {
       events.push({

packages/runtime-host/src/protocol/index.ts

@@ -92,7 +92,9 @@ export const RUNTIME_HOST_REGISTRATION_SCHEMA_VERSION = 1 as const;
 export const RUNTIME_HOST_PROTOCOL_VERSION = 0 as const;
 // Increment when the same protocol version no longer guarantees safe Client-Host
 // interoperability. Mismatches are rejected before domain commands are admitted.
-export const RUNTIME_HOST_COMPATIBILITY_EPOCH = 50 as const;
+export const RUNTIME_HOST_COMPATIBILITY_EPOCH = 51 as const;
+// 51: Failed Turn snapshots preserve the structured context-budget exhaustion
+// detail. Epoch-50 peers reject the optional field on the closed snapshot shape.
 // 50: WorkHub can append durable coordination summaries and admit tool-free
 // answers through its reserved Coordination Session authority.
 // 49: WorkHub resolves one durable Coordination Session per Runtime Host.