feat(telemetry): add usage metric for /btw command

packages/core/src/core/client.test.ts

@@ -21,7 +21,7 @@ import {
   type ContentGenerator,
   type ContentGeneratorConfig,
 } from './contentGenerator.js';
-import { GeminiChat } from './geminiChat.js';
+import { GeminiChat, StreamEventType, type StreamEvent } from './geminiChat.js';
 import type { Config } from '../config/config.js';
 import type { AgentLoopContext } from '../config/agent-loop-context.js';
 import {
@@ -50,6 +50,7 @@ import type {
 import { ClearcutLogger } from '../telemetry/clearcut-logger/clearcut-logger.js';
 import * as policyCatalog from '../availability/policyCatalog.js';
 import { LlmRole, LoopType } from '../telemetry/types.js';
+import { recordBtwUsageMetrics } from '../telemetry/index.js';
 import { partToString } from '../utils/partUtils.js';
 import { coreEvents, CoreEvent } from '../utils/events.js';
 import type { MessageBus } from '../confirmation-bus/message-bus.js';
@@ -130,6 +131,7 @@ vi.mock('../telemetry/index.js', () => ({
   logApiRequest: vi.fn(),
   logApiResponse: vi.fn(),
   logApiError: vi.fn(),
+  recordBtwUsageMetrics: vi.fn(),
 }));
 vi.mock('../ide/ideContext.js');
 vi.mock('../telemetry/uiTelemetry.js', () => ({
@@ -3294,6 +3296,48 @@ ${JSON.stringify(
     });
   });
 
+  describe('sendBtwStream', () => {
+    it('should record telemetry and call chat.sendBtwStream', async () => {
+      // Arrange
+      const request = [{ text: 'btw, how does this work?' }];
+      const abortSignal = new AbortController().signal;
+      const promptId = 'test-prompt-id';
+
+      const mockBtwStream = (async function* (): AsyncGenerator<
+        StreamEvent,
+        void,
+        unknown
+      > {
+        yield {
+          type: StreamEventType.CHUNK,
+          value: {
+            text: () => 'this works fine',
+          } as unknown as GenerateContentResponse,
+        };
+      })();
+
+      const sendBtwStreamSpy = vi
+        .spyOn(client.getChat(), 'sendBtwStream')
+        .mockReturnValue(mockBtwStream);
+
+      // Act
+      const stream = client.sendBtwStream(request, abortSignal, promptId);
+      for await (const _ of stream) {
+        // Consume stream
+      }
+
+      // Assert
+      expect(recordBtwUsageMetrics).toHaveBeenCalledWith(mockConfig);
+      expect(sendBtwStreamSpy).toHaveBeenCalledWith(
+        expect.any(Object), // modelConfigKey
+        request,
+        promptId,
+        abortSignal,
+        LlmRole.MAIN,
+      );
+    });
+  });
+
   describe('generateContent', () => {
     it('should call generateContent with the correct parameters', async () => {
       const contents = [{ role: 'user', parts: [{ text: 'hello' }] }];

packages/core/src/core/client.ts

@@ -50,6 +50,7 @@ import {
   logContentRetryFailure,
   logNextSpeakerCheck,
 } from '../telemetry/loggers.js';
+import { recordBtwUsageMetrics } from '../telemetry/index.js';
 import type {
   DefaultHookOutput,
   AfterAgentHookOutput,
@@ -1247,6 +1248,8 @@ export class GeminiClient {
 
     yield { type: GeminiEventType.ModelInfo, value: modelToUse };
 
+    recordBtwUsageMetrics(this.config);
+
     // Use a custom role for BTW to avoid side-effects in telemetry if needed,
     // but for now LlmRole.MAIN is fine as it's the primary model talking.
     const btwStream = this.getChat().sendBtwStream(

packages/core/src/telemetry/index.ts

@@ -129,6 +129,8 @@ export {
   recordGenAiClientTokenUsage,
   recordGenAiClientOperationDuration,
   getConventionAttributes,
+  // Btw Metrics
+  recordBtwUsageMetrics,
   // Performance monitoring functions
   recordStartupPerformance,
   recordMemoryUsage,

packages/core/src/telemetry/metrics.test.ts

@@ -104,6 +104,7 @@ describe('Telemetry Metrics', () => {
   let recordLinesChangedModule: typeof import('./metrics.js').recordLinesChanged;
   let recordSlowRenderModule: typeof import('./metrics.js').recordSlowRender;
   let recordPlanExecutionModule: typeof import('./metrics.js').recordPlanExecution;
+  let recordBtwUsageMetricsModule: typeof import('./metrics.js').recordBtwUsageMetrics;
   let recordKeychainAvailabilityModule: typeof import('./metrics.js').recordKeychainAvailability;
   let recordTokenStorageInitializationModule: typeof import('./metrics.js').recordTokenStorageInitialization;
   let recordInvalidChunkModule: typeof import('./metrics.js').recordInvalidChunk;
@@ -158,6 +159,7 @@ describe('Telemetry Metrics', () => {
     recordLinesChangedModule = metricsJsModule.recordLinesChanged;
     recordSlowRenderModule = metricsJsModule.recordSlowRender;
     recordPlanExecutionModule = metricsJsModule.recordPlanExecution;
+    recordBtwUsageMetricsModule = metricsJsModule.recordBtwUsageMetrics;
     recordKeychainAvailabilityModule =
       metricsJsModule.recordKeychainAvailability;
     recordTokenStorageInitializationModule =
@@ -273,6 +275,28 @@ describe('Telemetry Metrics', () => {
     });
   });
 
+  describe('recordBtwUsageMetrics', () => {
+    it('does not record metrics if not initialized', () => {
+      const config = makeFakeConfig({});
+      recordBtwUsageMetricsModule(config);
+      expect(mockCounterAddFn).not.toHaveBeenCalled();
+    });
+
+    it('records a btw usage event when initialized', () => {
+      const config = makeFakeConfig({});
+      initializeMetricsModule(config);
+      recordBtwUsageMetricsModule(config);
+
+      // Called for session, then for btw usage
+      expect(mockCounterAddFn).toHaveBeenCalledTimes(2);
+      expect(mockCounterAddFn).toHaveBeenNthCalledWith(2, 1, {
+        'session.id': 'test-session-id',
+        'installation.id': 'test-installation-id',
+        'user.email': 'test@example.com',
+      });
+    });
+  });
+
   describe('initializeMetrics', () => {
     const mockConfig = {
       getSessionId: () => 'test-session-id',

packages/core/src/telemetry/metrics.ts

@@ -101,6 +101,7 @@ const FLICKER_FRAME_COUNT = 'gemini_cli.ui.flicker.count';
 const SLOW_RENDER_LATENCY = 'gemini_cli.ui.slow_render.latency';
 const EXIT_FAIL_COUNT = 'gemini_cli.exit.fail.count';
 const PLAN_EXECUTION_COUNT = 'gemini_cli.plan.execution.count';
+const BTW_USAGE_COUNT = 'gemini_cli.btw.usage.count';
 
 const baseMetricDefinition = {
   getCommonAttributes,
@@ -269,6 +270,12 @@ const COUNTER_DEFINITIONS = {
       approval_mode: string;
     },
   },
+  [BTW_USAGE_COUNT]: {
+    description: 'Counts the usage of the /btw side inquiry command.',
+    valueType: ValueType.INT,
+    assign: (c: Counter) => (btwUsageCounter = c),
+    attributes: {} as Record<string, never>,
+  },
   [EVENT_HOOK_CALL_COUNT]: {
     description: 'Counts hook calls, tagged by hook event name and success.',
     valueType: ValueType.INT,
@@ -777,6 +784,7 @@ let agentRecoveryAttemptDurationHistogram: Histogram | undefined;
 let flickerFrameCounter: Counter | undefined;
 let exitFailCounter: Counter | undefined;
 let planExecutionCounter: Counter | undefined;
+let btwUsageCounter: Counter | undefined;
 let slowRenderHistogram: Histogram | undefined;
 let hookCallCounter: Counter | undefined;
 let hookCallLatencyHistogram: Histogram | undefined;
@@ -1034,6 +1042,14 @@ export function recordPlanExecution(
   });
 }
 
+/**
+ * Records a metric for when the /btw side inquiry command is used
+ */
+export function recordBtwUsageMetrics(config: Config): void {
+  if (!btwUsageCounter || !isMetricsInitialized) return;
+  btwUsageCounter.add(1, baseMetricDefinition.getCommonAttributes(config));
+}
+
 /**
  * Records a metric for when a UI frame is slow in rendering
  */