feat(hooks): Hook Session Lifecycle & Compression Integration (#14151)

packages/cli/src/ui/AppContainer.tsx

@@ -59,6 +59,10 @@ import {
   disableLineWrapping,
   shouldEnterAlternateScreen,
   startupProfiler,
+  SessionStartSource,
+  SessionEndReason,
+  fireSessionStartHook,
+  fireSessionEndHook,
 } from '@google/gemini-cli-core';
 import { validateAuthMethod } from '../config/auth.js';
 import process from 'node:process';
@@ -284,14 +288,32 @@ export const AppContainer = (props: AppContainerProps) => {
       await config.initialize();
       setConfigInitialized(true);
       startupProfiler.flush(config);
+
+      // Fire SessionStart hook through MessageBus (only if hooks are enabled)
+      // Must be called AFTER config.initialize() to ensure HookRegistry is loaded
+      const hooksEnabled = config.getEnableHooks();
+      const hookMessageBus = config.getMessageBus();
+      if (hooksEnabled && hookMessageBus) {
+        const sessionStartSource = resumedSessionData
+          ? SessionStartSource.Resume
+          : SessionStartSource.Startup;
+        await fireSessionStartHook(hookMessageBus, sessionStartSource);
+      }
     })();
     registerCleanup(async () => {
       // Turn off mouse scroll.
       disableMouseEvents();
       const ideClient = await IdeClient.getInstance();
       await ideClient.disconnect();
+
+      // Fire SessionEnd hook on cleanup (only if hooks are enabled)
+      const hooksEnabled = config.getEnableHooks();
+      const hookMessageBus = config.getMessageBus();
+      if (hooksEnabled && hookMessageBus) {
+        await fireSessionEndHook(hookMessageBus, SessionEndReason.Exit);
+      }
     });
-  }, [config]);
+  }, [config, resumedSessionData]);
 
   useEffect(
     () => setUpdateHandler(historyManager.addItem, setUpdateInfo),

packages/cli/src/ui/commands/clearCommand.test.ts

@@ -44,6 +44,8 @@ describe('clearCommand', () => {
               }),
             }) as unknown as GeminiClient,
           setSessionId: vi.fn(),
+          getEnableHooks: vi.fn().mockReturnValue(false),
+          getMessageBus: vi.fn().mockReturnValue(undefined),
         },
       },
     });

packages/cli/src/ui/commands/clearCommand.ts

@@ -4,7 +4,14 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import { uiTelemetryService } from '@google/gemini-cli-core';
+import {
+  uiTelemetryService,
+  fireSessionEndHook,
+  fireSessionStartHook,
+  SessionEndReason,
+  SessionStartSource,
+  flushTelemetry,
+} from '@google/gemini-cli-core';
 import type { SlashCommand } from './types.js';
 import { CommandKind } from './types.js';
 import { randomUUID } from 'node:crypto';
@@ -21,6 +28,12 @@ export const clearCommand: SlashCommand = {
       ?.getGeminiClient()
       ?.getChat()
       .getChatRecordingService();
+    const messageBus = config?.getMessageBus();
+
+    // Fire SessionEnd hook before clearing
+    if (config?.getEnableHooks() && messageBus) {
+      await fireSessionEndHook(messageBus, SessionEndReason.Clear);
+    }
 
     if (geminiClient) {
       context.ui.setDebugMessage('Clearing terminal and resetting chat.');
@@ -38,6 +51,21 @@ export const clearCommand: SlashCommand = {
       chatRecordingService.initialize();
     }
 
+    // Fire SessionStart hook after clearing
+    if (config?.getEnableHooks() && messageBus) {
+      await fireSessionStartHook(messageBus, SessionStartSource.Clear);
+    }
+
+    // Give the event loop a chance to process any pending telemetry operations
+    // This ensures logger.emit() calls have fully propagated to the BatchLogRecordProcessor
+    await new Promise((resolve) => setImmediate(resolve));
+
+    // Flush telemetry to ensure hooks are written to disk immediately
+    // This is critical for tests and environments with I/O latency
+    if (config) {
+      await flushTelemetry(config);
+    }
+
     uiTelemetryService.setLastPromptTokenCount(0);
     context.ui.clear();
   },