feat(sessions): use 1-line generated session summary to describe sessions (#14467)

packages/core/src/services/sessionSummaryUtils.ts

@@ -0,0 +1,69 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import type { Config } from '../config/config.js';
+import { SessionSummaryService } from './sessionSummaryService.js';
+import { BaseLlmClient } from '../core/baseLlmClient.js';
+import { debugLogger } from '../utils/debugLogger.js';
+
+/**
+ * Generates and saves a summary for the current session.
+ * This is called during session cleanup and is non-blocking - errors are logged but don't prevent exit.
+ */
+export async function generateAndSaveSummary(config: Config): Promise<void> {
+  try {
+    // Get the chat recording service from config
+    const chatRecordingService = config
+      .getGeminiClient()
+      ?.getChatRecordingService();
+    if (!chatRecordingService) {
+      debugLogger.debug('[SessionSummary] No chat recording service available');
+      return;
+    }
+
+    // Get the current conversation
+    const conversation = chatRecordingService.getConversation();
+    if (!conversation) {
+      debugLogger.debug('[SessionSummary] No conversation to summarize');
+      return;
+    }
+
+    // Skip if summary already exists (e.g., resumed session)
+    if (conversation.summary) {
+      debugLogger.debug('[SessionSummary] Summary already exists, skipping');
+      return;
+    }
+
+    // Skip if no messages
+    if (conversation.messages.length === 0) {
+      debugLogger.debug('[SessionSummary] No messages to summarize');
+      return;
+    }
+
+    // Create summary service
+    const contentGenerator = config.getContentGenerator();
+    const baseLlmClient = new BaseLlmClient(contentGenerator, config);
+    const summaryService = new SessionSummaryService(baseLlmClient);
+
+    // Generate summary
+    const summary = await summaryService.generateSummary({
+      messages: conversation.messages,
+    });
+
+    // Save summary if generated successfully
+    if (summary) {
+      chatRecordingService.saveSummary(summary);
+      debugLogger.debug(`[SessionSummary] Saved summary: "${summary}"`);
+    } else {
+      debugLogger.warn('[SessionSummary] Failed to generate summary');
+    }
+  } catch (error) {
+    // Log but don't throw - we want graceful degradation
+    debugLogger.warn(
+      `[SessionSummary] Error in generateAndSaveSummary: ${error instanceof Error ? error.message : String(error)}`,
+    );
+  }
+}