🤖 feat: enhance telemetry with runtime, platform, and usage tracking (#932)

## Summary

Add comprehensive telemetry enhancements for better product insights.

### Runtime & Platform Data
- Add `runtimeType` (local/worktree/ssh) to `workspace_created` and
`message_sent`
- Add frontend platform info (userAgent, platform) for `mux server` mode
- Enhance backend platform data with `nodeVersion` and `bunVersion`

### New Events

| Event | Purpose | Fields |
|-------|---------|--------|
| `stream_completed` | Track completion vs interruption | model,
wasInterrupted, duration_b2, output_tokens_b2 |
| `provider_configured` | Track provider setup (not keys!) | provider,
keyType |
| `command_used` | Track slash command usage | command type |
| `voice_transcription` | Track voice input adoption |
audio_duration_b2, success |

### Enhanced Events

| Event | Enhancement |
|-------|-------------|
| `app_started` | Added `vimModeEnabled` |
| `message_sent` | Added `thinkingLevel` |

### Privacy

All metrics use base-2 rounding for privacy-preserving numerical data.
No sensitive information (SSH hosts, API keys, project names, etc.) is
ever sent.

---
_Generated with `mux`_

Author: ammar-agent

docs/system-prompt.md

@@ -62,5 +62,4 @@ You are in a git worktree at ${workspacePath}
 }
 ```
 
-
 {/* END SYSTEM_PROMPT_DOCS */}

src/browser/App.tsx

@@ -33,6 +33,7 @@ import { isWorkspaceForkSwitchEvent } from "./utils/workspaceEvents";
 import { getThinkingLevelKey } from "@/common/constants/storage";
 import type { BranchListResult } from "@/common/orpc/types";
 import { useTelemetry } from "./hooks/useTelemetry";
+import { getRuntimeTypeForTelemetry } from "@/common/telemetry";
 import { useStartWorkspaceCreation, getFirstProjectPath } from "./hooks/useStartWorkspaceCreation";
 import { useAPI } from "@/browser/contexts/API";
 import { AuthTokenModal } from "@/browser/components/AuthTokenModal";
@@ -640,7 +641,10 @@ function AppInner() {
                             });
 
                             // Track telemetry
-                            telemetry.workspaceCreated(metadata.id);
+                            telemetry.workspaceCreated(
+                              metadata.id,
+                              getRuntimeTypeForTelemetry(metadata.runtimeConfig)
+                            );
 
                             // Clear pending state
                             clearPendingWorkspaceCreation();

src/browser/components/AIView.tsx

@@ -33,6 +33,7 @@ import { WorkspaceHeader } from "./WorkspaceHeader";
 import { getModelName } from "@/common/utils/ai/models";
 import type { DisplayedMessage } from "@/common/types/message";
 import type { RuntimeConfig } from "@/common/types/runtime";
+import { getRuntimeTypeForTelemetry } from "@/common/telemetry";
 import { useAIViewKeybinds } from "@/browser/hooks/useAIViewKeybinds";
 import { evictModelFromLRU } from "@/browser/hooks/useModelLRU";
 import { QueuedMessage } from "./Messages/QueuedMessage";
@@ -620,6 +621,7 @@ const AIViewInner: React.FC<AIViewProps> = ({
         <ChatInput
           variant="workspace"
           workspaceId={workspaceId}
+          runtimeType={getRuntimeTypeForTelemetry(runtimeConfig)}
           onMessageSent={handleMessageSent}
           onTruncateHistory={handleClearHistory}
           onProviderConfig={handleProviderConfig}

src/browser/components/ChatInput/index.tsx

@@ -119,6 +119,8 @@ export const ChatInput: React.FC<ChatInputProps> = (props) => {
   const editingMessage = variant === "workspace" ? props.editingMessage : undefined;
   const isCompacting = variant === "workspace" ? (props.isCompacting ?? false) : false;
   const canInterrupt = variant === "workspace" ? (props.canInterrupt ?? false) : false;
+  // runtimeType for telemetry - defaults to "worktree" if not provided
+  const runtimeType = variant === "workspace" ? (props.runtimeType ?? "worktree") : "worktree";
 
   // Storage keys differ by variant
   const storageKeys = (() => {
@@ -1015,7 +1017,13 @@ export const ChatInput: React.FC<ChatInputProps> = (props) => {
           setImageAttachments(previousImageAttachments);
         } else {
           // Track telemetry for successful message send
-          telemetry.messageSent(sendMessageOptions.model, mode, actualMessageText.length);
+          telemetry.messageSent(
+            sendMessageOptions.model,
+            mode,
+            actualMessageText.length,
+            runtimeType,
+            sendMessageOptions.thinkingLevel ?? "off"
+          );
 
           // Exit editing mode if we were editing
           if (editingMessage && props.onCancelEdit) {

src/browser/components/ChatInput/types.ts

@@ -1,5 +1,6 @@
 import type { ImagePart } from "@/common/orpc/types";
 import type { FrontendWorkspaceMetadata } from "@/common/types/workspace";
+import type { TelemetryRuntimeType } from "@/common/telemetry/payload";
 import type { AutoCompactionCheckResult } from "@/browser/utils/compaction/autoCompactionCheck";
 
 export interface ChatInputAPI {
@@ -14,6 +15,8 @@ export interface ChatInputAPI {
 export interface ChatInputWorkspaceVariant {
   variant: "workspace";
   workspaceId: string;
+  /** Runtime type for the workspace (for telemetry) - no sensitive details like SSH host */
+  runtimeType?: TelemetryRuntimeType;
   onMessageSent?: () => void;
   onTruncateHistory: (percentage?: number) => Promise<void>;
   onProviderConfig?: (provider: string, keyPath: string[], value: string) => Promise<void>;

src/browser/hooks/useTelemetry.ts

@@ -1,80 +1,95 @@
 import { useCallback } from "react";
-import { trackEvent, roundToBase2 } from "@/common/telemetry";
-import type { ErrorContext } from "@/common/telemetry/payload";
+import {
+  trackWorkspaceCreated,
+  trackWorkspaceSwitched,
+  trackMessageSent,
+  trackStreamCompleted,
+  trackProviderConfigured,
+  trackCommandUsed,
+  trackVoiceTranscription,
+  trackErrorOccurred,
+} from "@/common/telemetry";
+import type {
+  ErrorContext,
+  TelemetryRuntimeType,
+  TelemetryThinkingLevel,
+  TelemetryCommandType,
+} from "@/common/telemetry/payload";
 
 /**
  * Hook for clean telemetry integration in React components
  *
- * Provides type-safe telemetry tracking. Base properties (version, platform, etc.)
- * are automatically added by the backend TelemetryService.
+ * Provides stable callback references for telemetry tracking.
+ * All numeric values are automatically rounded for privacy.
  *
  * Usage:
  *
  * ```tsx
  * const telemetry = useTelemetry();
  *
- * // Track workspace switch
  * telemetry.workspaceSwitched(fromId, toId);
- *
- * // Track workspace creation
- * telemetry.workspaceCreated(workspaceId);
- *
- * // Track message sent
- * telemetry.messageSent(model, mode, messageLength);
- *
- * // Track error
+ * telemetry.workspaceCreated(workspaceId, runtimeType);
+ * telemetry.messageSent(model, mode, messageLength, runtimeType, thinkingLevel);
+ * telemetry.streamCompleted(model, wasInterrupted, durationSecs, outputTokens);
+ * telemetry.providerConfigured(provider, keyType);
+ * telemetry.commandUsed(commandType);
+ * telemetry.voiceTranscription(audioDurationSecs, success);
  * telemetry.errorOccurred(errorType, context);
  * ```
  */
 export function useTelemetry() {
   const workspaceSwitched = useCallback((fromWorkspaceId: string, toWorkspaceId: string) => {
-    console.debug("[useTelemetry] workspaceSwitched called", { fromWorkspaceId, toWorkspaceId });
-    trackEvent({
-      event: "workspace_switched",
-      properties: {
-        fromWorkspaceId,
-        toWorkspaceId,
-      },
-    });
+    trackWorkspaceSwitched(fromWorkspaceId, toWorkspaceId);
+  }, []);
+
+  const workspaceCreated = useCallback((workspaceId: string, runtimeType: TelemetryRuntimeType) => {
+    trackWorkspaceCreated(workspaceId, runtimeType);
+  }, []);
+
+  const messageSent = useCallback(
+    (
+      model: string,
+      mode: string,
+      messageLength: number,
+      runtimeType: TelemetryRuntimeType,
+      thinkingLevel: TelemetryThinkingLevel
+    ) => {
+      trackMessageSent(model, mode, messageLength, runtimeType, thinkingLevel);
+    },
+    []
+  );
+
+  const streamCompleted = useCallback(
+    (model: string, wasInterrupted: boolean, durationSecs: number, outputTokens: number) => {
+      trackStreamCompleted(model, wasInterrupted, durationSecs, outputTokens);
+    },
+    []
+  );
+
+  const providerConfigured = useCallback((provider: string, keyType: string) => {
+    trackProviderConfigured(provider, keyType);
   }, []);
 
-  const workspaceCreated = useCallback((workspaceId: string) => {
-    console.debug("[useTelemetry] workspaceCreated called", { workspaceId });
-    trackEvent({
-      event: "workspace_created",
-      properties: {
-        workspaceId,
-      },
-    });
+  const commandUsed = useCallback((command: TelemetryCommandType) => {
+    trackCommandUsed(command);
   }, []);
 
-  const messageSent = useCallback((model: string, mode: string, messageLength: number) => {
-    console.debug("[useTelemetry] messageSent called", { model, mode, messageLength });
-    trackEvent({
-      event: "message_sent",
-      properties: {
-        model,
-        mode,
-        message_length_b2: roundToBase2(messageLength),
-      },
-    });
+  const voiceTranscription = useCallback((audioDurationSecs: number, success: boolean) => {
+    trackVoiceTranscription(audioDurationSecs, success);
   }, []);
 
   const errorOccurred = useCallback((errorType: string, context: ErrorContext) => {
-    console.debug("[useTelemetry] errorOccurred called", { errorType, context });
-    trackEvent({
-      event: "error_occurred",
-      properties: {
-        errorType,
-        context,
-      },
-    });
+    trackErrorOccurred(errorType, context);
   }, []);
 
   return {
     workspaceSwitched,
     workspaceCreated,
     messageSent,
+    streamCompleted,
+    providerConfigured,
+    commandUsed,
+    voiceTranscription,
     errorOccurred,
   };
 }

src/browser/hooks/useVoiceInput.ts

@@ -9,6 +9,7 @@
 import { useState, useCallback, useRef, useEffect } from "react";
 import { matchesKeybind, KEYBINDS } from "@/browser/utils/ui/keybinds";
 import type { APIClient } from "@/browser/contexts/API";
+import { trackVoiceTranscription } from "@/common/telemetry";
 
 export type VoiceInputState = "idle" | "recording" | "transcribing";
 
@@ -117,6 +118,9 @@ export function useVoiceInput(options: UseVoiceInputOptions): UseVoiceInputResul
   const shouldSendRef = useRef(false);
   const wasCancelledRef = useRef(false);
 
+  // Track recording start time for duration telemetry
+  const recordingStartTimeRef = useRef<number>(0);
+
   // Keep callbacks fresh without recreating functions
   const callbacksRef = useRef(options);
   useEffect(() => {
@@ -134,6 +138,9 @@ export function useVoiceInput(options: UseVoiceInputOptions): UseVoiceInputResul
     const shouldSend = shouldSendRef.current;
     shouldSendRef.current = false;
 
+    // Calculate recording duration for telemetry
+    const audioDurationSecs = (Date.now() - recordingStartTimeRef.current) / 1000;
+
     try {
       // Encode audio as base64 for IPC transport
       const buffer = await audioBlob.arrayBuffer();
@@ -144,18 +151,27 @@ export function useVoiceInput(options: UseVoiceInputOptions): UseVoiceInputResul
       const api = callbacksRef.current.api;
       if (!api) {
         callbacksRef.current.onError?.("Voice API not available");
+        trackVoiceTranscription(audioDurationSecs, false);
         return;
       }
 
       const result = await api.voice.transcribe({ audioBase64: base64 });
 
       if (!result.success) {
         callbacksRef.current.onError?.(result.error);
+        trackVoiceTranscription(audioDurationSecs, false);
         return;
       }
 
       const text = result.data.trim();
-      if (!text) return; // Empty transcription, nothing to do
+      if (!text) {
+        // Track empty transcription as success (API worked, just no speech)
+        trackVoiceTranscription(audioDurationSecs, true);
+        return;
+      }
+
+      // Track successful transcription
+      trackVoiceTranscription(audioDurationSecs, true);
 
       callbacksRef.current.onTranscript(text);
 
@@ -166,6 +182,7 @@ export function useVoiceInput(options: UseVoiceInputOptions): UseVoiceInputResul
     } catch (err) {
       const msg = err instanceof Error ? err.message : String(err);
       callbacksRef.current.onError?.(`Transcription failed: ${msg}`);
+      trackVoiceTranscription(audioDurationSecs, false);
     } finally {
       setState("idle");
     }
@@ -235,6 +252,7 @@ export function useVoiceInput(options: UseVoiceInputOptions): UseVoiceInputResul
       recorderRef.current = recorder;
       setMediaRecorder(recorder);
       recorder.start();
+      recordingStartTimeRef.current = Date.now();
       setState("recording");
     } catch (err) {
       const msg = err instanceof Error ? err.message : String(err);

src/browser/stores/WorkspaceStore.ts

@@ -18,13 +18,15 @@ import {
   isQueuedMessageChanged,
   isRestoreToInput,
 } from "@/common/orpc/types";
+import type { StreamEndEvent, StreamAbortEvent } from "@/common/types/stream";
 import { MapStore } from "./MapStore";
 import { collectUsageHistory, createDisplayUsage } from "@/common/utils/tokens/displayUsage";
 import { WorkspaceConsumerManager } from "./WorkspaceConsumerManager";
 import type { ChatUsageDisplay } from "@/common/utils/tokens/usageAggregator";
 import type { TokenConsumer } from "@/common/types/chatStats";
 import type { LanguageModelV2Usage } from "@ai-sdk/provider";
 import { createFreshRetryState } from "@/browser/utils/messages/retryState";
+import { trackStreamCompleted } from "@/common/telemetry";
 
 export interface WorkspaceState {
   name: string; // User-facing workspace name (e.g., "feature-branch")
@@ -155,23 +157,43 @@ export class WorkspaceStore {
       this.states.bump(workspaceId);
     },
     "stream-end": (workspaceId, aggregator, data) => {
-      aggregator.handleStreamEnd(data as never);
-      aggregator.clearTokenState((data as { messageId: string }).messageId);
+      const streamEndData = data as StreamEndEvent;
+      aggregator.handleStreamEnd(streamEndData as never);
+      aggregator.clearTokenState(streamEndData.messageId);
+
+      // Track stream completion telemetry
+      this.trackStreamCompletedTelemetry(streamEndData, false);
 
       // Reset retry state on successful stream completion
       updatePersistedState(getRetryStateKey(workspaceId), createFreshRetryState());
 
       this.states.bump(workspaceId);
       this.checkAndBumpRecencyIfChanged();
-      this.finalizeUsageStats(workspaceId, (data as { metadata?: never }).metadata);
+      this.finalizeUsageStats(workspaceId, streamEndData.metadata);
     },
     "stream-abort": (workspaceId, aggregator, data) => {
-      aggregator.clearTokenState((data as { messageId: string }).messageId);
-      aggregator.handleStreamAbort(data as never);
+      const streamAbortData = data as StreamAbortEvent;
+      aggregator.clearTokenState(streamAbortData.messageId);
+      aggregator.handleStreamAbort(streamAbortData as never);
+
+      // Track stream interruption telemetry (get model from aggregator)
+      const model = aggregator.getCurrentModel();
+      if (model) {
+        this.trackStreamCompletedTelemetry(
+          {
+            metadata: {
+              model,
+              usage: streamAbortData.metadata?.usage,
+              duration: streamAbortData.metadata?.duration,
+            },
+          },
+          true
+        );
+      }
 
       this.states.bump(workspaceId);
       this.dispatchResumeCheck(workspaceId);
-      this.finalizeUsageStats(workspaceId, (data as { metadata?: never }).metadata);
+      this.finalizeUsageStats(workspaceId, streamAbortData.metadata);
     },
     "tool-call-start": (workspaceId, aggregator, data) => {
       aggregator.handleToolCallStart(data as never);
@@ -282,6 +304,27 @@ export class WorkspaceStore {
     window.dispatchEvent(createCustomEvent(CUSTOM_EVENTS.RESUME_CHECK_REQUESTED, { workspaceId }));
   }
 
+  /**
+   * Track stream completion telemetry
+   */
+  private trackStreamCompletedTelemetry(
+    data: {
+      metadata: {
+        model: string;
+        usage?: { outputTokens?: number };
+        duration?: number;
+      };
+    },
+    wasInterrupted: boolean
+  ): void {
+    const { metadata } = data;
+    const durationSecs = metadata.duration ? metadata.duration / 1000 : 0;
+    const outputTokens = metadata.usage?.outputTokens ?? 0;
+
+    // trackStreamCompleted handles rounding internally
+    trackStreamCompleted(metadata.model, wasInterrupted, durationSecs, outputTokens);
+  }
+
   /**
    * Check if any workspace's recency changed and bump global recency if so.
    * Uses cached recency values from aggregators for O(1) comparison per workspace.