feat(cli): add /insights slash command to analyze past sessions

packages/cli/src/services/BuiltinCommandLoader.ts

@@ -31,6 +31,7 @@ import { directoryCommand } from '../ui/commands/directoryCommand.js';
 import { editorCommand } from '../ui/commands/editorCommand.js';
 import { extensionsCommand } from '../ui/commands/extensionsCommand.js';
 import { helpCommand } from '../ui/commands/helpCommand.js';
+import { insightsCommand } from '../ui/commands/insightsCommand.js';
 import { shortcutsCommand } from '../ui/commands/shortcutsCommand.js';
 import { rewindCommand } from '../ui/commands/rewindCommand.js';
 import { hooksCommand } from '../ui/commands/hooksCommand.js';
@@ -117,6 +118,7 @@ export class BuiltinCommandLoader implements ICommandLoader {
           ]
         : [extensionsCommand(this.config?.getEnableExtensionReloading())]),
       helpCommand,
+      insightsCommand,
       shortcutsCommand,
       ...(this.config?.getEnableHooksUI() ? [hooksCommand] : []),
       rewindCommand,

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

@@ -0,0 +1,56 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { InsightsService } from '@google/gemini-cli-core';
+import { MessageType } from '../types.js';
+import {
+  type CommandContext,
+  type SlashCommand,
+  CommandKind,
+} from './types.js';
+
+/**
+ * Slash command to generate usage insights based on past sessions.
+ */
+export const insightsCommand: SlashCommand = {
+  name: 'insights',
+  description: 'Analyze past sessions and get usage improvements and summary.',
+  kind: CommandKind.BUILT_IN,
+  autoExecute: true,
+  action: async (context: CommandContext) => {
+    const config = context.services.config;
+    if (!config) {
+      context.ui.addItem({
+        type: MessageType.ERROR,
+        text: 'Config is not available.',
+      });
+      return;
+    }
+
+    context.ui.addItem({
+      type: MessageType.INFO,
+      text: 'Analyzing your past sessions to generate insights...',
+    });
+
+    try {
+      const insightsService = new InsightsService(config);
+      const baseLlmClient = config.getBaseLlmClient();
+
+      const reportMarkdown =
+        await insightsService.generateInsightsReport(baseLlmClient);
+
+      context.ui.addItem({
+        type: MessageType.GEMINI,
+        text: reportMarkdown,
+      });
+    } catch (error) {
+      context.ui.addItem({
+        type: MessageType.ERROR,
+        text: `Failed to generate insights: ${error instanceof Error ? error.message : String(error)}`,
+      });
+    }
+  },
+};