feat(web): rename PostHog chat events, add tool_used tracking, and client-side ask events

CHANGELOG.md

@@ -13,6 +13,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 - Deprecated `GOOGLE_VERTEX_THINKING_BUDGET_TOKENS` environment variable in favor of per-model `thinkingBudget` config. [#1110](https://github.com/sourcebot-dev/sourcebot/pull/1110)
 - Removed `GOOGLE_VERTEX_INCLUDE_THOUGHTS` environment variable. Thoughts are now always included. [#1110](https://github.com/sourcebot-dev/sourcebot/pull/1110)
+- Renamed and consolidated PostHog chat events (`wa_chat_thread_created` -> `ask_thread_created`, `wa_chat_message_sent` -> `ask_message_sent`, `wa_chat_tool_used` -> `tool_used`), added unified `tool_used` tracking across the ask agent and MCP server, and removed the redundant `api_code_search_request` event. [#1111](https://github.com/sourcebot-dev/sourcebot/pull/1111)
 
 ## [4.16.8] - 2026-04-09
 

CLAUDE.md

@@ -57,6 +57,12 @@ if (!value) { return; }
 if (condition) doSomething();
 ```
 
+## PostHog Event Naming
+
+- The `wa_` prefix is reserved for events that can ONLY be fired from the web app (e.g., `wa_login_with_github`, `wa_chat_feedback_submitted`).
+- Events fired from multiple sources (web app, MCP server, API) must NOT use the `wa_` prefix (e.g., `ask_message_sent`, `tool_used`).
+- Multi-source events should include a `source` property to identify the origin (e.g., `'sourcebot-web-client'`, `'sourcebot-mcp-server'`, `'sourcebot-ask-agent'`).
+
 ## Tailwind CSS
 
 Use Tailwind color classes directly instead of CSS variable syntax:

packages/web/src/app/api/(server)/chat/route.ts

@@ -91,12 +91,15 @@ export const POST = apiHandler(async (req: NextRequest) => {
                 return [];
             }))).flat();
 
-            await captureEvent('wa_chat_message_sent', {
+            const source = req.headers.get('X-Sourcebot-Client-Source') ?? undefined;
+
+            await captureEvent('ask_message_sent', {
                 chatId: id,
                 messageCount: messages.length,
                 selectedReposCount: expandedRepos.length,
+                source,
                 ...(env.EXPERIMENT_ASK_GH_ENABLED === 'true' ? { selectedRepos: expandedRepos } : {}),
-            } );
+            });
 
             const stream = await createMessageStream({
                 chatId: id,
@@ -109,6 +112,7 @@ export const POST = apiHandler(async (req: NextRequest) => {
                 modelName: languageModelConfig.displayName ?? languageModelConfig.model,
                 modelProviderOptions: providerOptions,
                 modelTemperature: temperature,
+                userId: user?.id,
                 onFinish: async ({ messages }) => {
                     await updateChatMessages({ chatId: id, messages, prisma });
                 },

packages/web/src/app/api/(server)/mcp/route.ts

@@ -79,7 +79,7 @@ export const POST = apiHandler(async (request: NextRequest) => {
                 },
             });
 
-            const mcpServer = await createMcpServer();
+            const mcpServer = await createMcpServer({ userId: user?.id });
             await mcpServer.connect(transport);
 
             return transport.handleRequest(request);

packages/web/src/app/api/(server)/search/route.ts

@@ -2,7 +2,6 @@
 
 import { search, searchRequestSchema } from "@/features/search";
 import { apiHandler } from "@/lib/apiHandler";
-import { captureEvent } from "@/lib/posthog";
 import { requestBodySchemaValidationError, serviceErrorResponse } from "@/lib/serviceError";
 import { isServiceError } from "@/lib/utils";
 import { NextRequest } from "next/server";
@@ -21,12 +20,6 @@ export const POST = apiHandler(async (request: NextRequest) => {
         ...options
     } = parsed.data;
 
-    const source = request.headers.get('X-Sourcebot-Client-Source') ?? 'unknown';
-    await captureEvent('api_code_search_request', {
-        source,
-        type: 'blocking',
-    });
-
     const response = await search({
         queryType: 'string',
         query,

packages/web/src/app/api/(server)/stream_search/route.ts

@@ -2,7 +2,6 @@
 
 import { streamSearch, searchRequestSchema } from '@/features/search';
 import { apiHandler } from '@/lib/apiHandler';
-import { captureEvent } from '@/lib/posthog';
 import { requestBodySchemaValidationError, serviceErrorResponse } from '@/lib/serviceError';
 import { isServiceError } from '@/lib/utils';
 import { NextRequest } from 'next/server';
@@ -20,12 +19,6 @@ export const POST = apiHandler(async (request: NextRequest) => {
         ...options
     } = parsed.data;
 
-    const source = request.headers.get('X-Sourcebot-Client-Source') ?? 'unknown';
-    await captureEvent('api_code_search_request', {
-        source,
-        type: 'streamed',
-    });
-
     const stream = await streamSearch({
         queryType: 'string',
         query,

packages/web/src/features/chat/actions.ts

@@ -49,9 +49,10 @@ export const createChat = async ({ source }: { source?: string } = {}) => sew(()
             });
         }
 
-        await captureEvent('wa_chat_thread_created', {
+        await captureEvent('ask_thread_created', {
             chatId: chat.id,
             isAnonymous: isGuestUser,
+            source,
         });
 
         return {

packages/web/src/features/chat/agent.ts

@@ -1,7 +1,6 @@
 import { SBChatMessage, SBChatMessageMetadata } from "@/features/chat/types";
 import { getAnswerPartFromAssistantMessage } from "@/features/chat/utils";
 import { getFileSource } from '@/features/git';
-import { captureEvent } from "@/lib/posthog";
 import { isServiceError } from "@/lib/utils";
 import { LanguageModelV3 as AISDKLanguageModelV3 } from "@ai-sdk/provider";
 import { ProviderOptions } from "@ai-sdk/provider-utils";
@@ -44,6 +43,8 @@ interface CreateMessageStreamResponseProps {
     modelProviderOptions?: Record<string, Record<string, JSONValue>>;
     modelTemperature?: number;
     metadata?: Partial<SBChatMessageMetadata>;
+    /** User ID for telemetry attribution on tool_used events. */
+    userId?: string;
 }
 
 export const createMessageStream = async ({
@@ -57,6 +58,7 @@ export const createMessageStream = async ({
     modelTemperature,
     onFinish,
     onError,
+    userId,
 }: CreateMessageStreamResponseProps) => {
     const latestMessage = messages[messages.length - 1];
     const sources = latestMessage.parts
@@ -102,6 +104,7 @@ export const createMessageStream = async ({
                 inputMessages: messageHistory,
                 inputSources: sources,
                 selectedRepos,
+                userId,
                 onWriteSource: (source) => {
                     writer.write({
                         type: 'data-source',
@@ -155,6 +158,7 @@ interface AgentOptions {
     onWriteSource: (source: Source) => void;
     traceId: string;
     chatId: string;
+    userId?: string;
 }
 
 const createAgentStream = async ({
@@ -167,6 +171,7 @@ const createAgentStream = async ({
     onWriteSource,
     traceId,
     chatId,
+    userId,
 }: AgentOptions) => {
     // For every file source, resolve the source code so that we can include it in the system prompt.
     const fileSources = inputSources.filter((source) => source.type === 'file');
@@ -203,20 +208,14 @@ const createAgentStream = async ({
         providerOptions,
         messages: inputMessages,
         system: systemPrompt,
-        tools: createTools({ source: 'sourcebot-ask-agent', selectedRepos }),
+        tools: createTools({ source: 'sourcebot-ask-agent', selectedRepos, userId }),
         temperature: temperature ?? env.SOURCEBOT_CHAT_MODEL_TEMPERATURE,
         stopWhen: [
             stepCountIsGTE(env.SOURCEBOT_CHAT_MAX_STEP_COUNT),
         ],
         toolChoice: "auto",
         onStepFinish: ({ toolResults }) => {
-            toolResults.forEach(({ toolName, output, dynamic }) => {
-                captureEvent('wa_chat_tool_used', {
-                    chatId,
-                    toolName,
-                    success: !isServiceError(output),
-                });
-
+            toolResults.forEach(({ output, dynamic }) => {
                 if (dynamic || isServiceError(output)) {
                     return;
                 }

packages/web/src/features/chat/components/chatThread/chatThread.tsx

@@ -102,6 +102,9 @@ export const ChatThread = ({
         messages: initialMessages,
         transport: new DefaultChatTransport({
             api: '/api/chat',
+            headers: {
+                'X-Sourcebot-Client-Source': 'sourcebot-web-client',
+            },
         }),
         onData: (dataPart) => {
             // Keeps sources added by the assistant in sync.

packages/web/src/features/mcp/askCodebase.ts

@@ -86,9 +86,10 @@ export const askCodebase = (params: AskCodebaseParams): Promise<AskCodebaseResul
                 },
             });
 
-            await captureEvent('wa_chat_thread_created', {
+            await captureEvent('ask_thread_created', {
                 chatId: chat.id,
                 isAnonymous: !user,
+                source,
             });
 
             if (user) {
@@ -137,10 +138,11 @@ export const askCodebase = (params: AskCodebaseParams): Promise<AskCodebaseResul
 
             let finalMessages: SBChatMessage[] = [];
 
-            await captureEvent('wa_chat_message_sent', {
+            await captureEvent('ask_message_sent', {
                 chatId: chat.id,
                 messageCount: 1,
                 selectedReposCount: selectedRepos.length,
+                source,
                 ...(env.EXPERIMENT_ASK_GH_ENABLED === 'true' ? {
                     selectedRepos: selectedRepos.map(r => r.value)
                 } : {}),
@@ -157,6 +159,7 @@ export const askCodebase = (params: AskCodebaseParams): Promise<AskCodebaseResul
                 modelName,
                 modelProviderOptions: providerOptions,
                 modelTemperature: temperature,
+                userId: user?.id,
                 onFinish: async ({ messages }) => {
                     finalMessages = messages;
                 },

packages/web/src/features/mcp/server.ts

@@ -2,6 +2,7 @@ import {
     languageModelInfoSchema,
 } from '@/features/chat/types';
 import { askCodebase } from '@/features/mcp/askCodebase';
+import { captureEvent } from '@/lib/posthog';
 import { isServiceError } from '@/lib/utils';
 import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
 import { ChatVisibility } from '@sourcebot/db';
@@ -24,7 +25,7 @@ import {
 
 const dedent = _dedent.withOptions({ alignValues: true });
 
-export async function createMcpServer(): Promise<McpServer> {
+export async function createMcpServer(options?: { userId?: string }): Promise<McpServer> {
     const server = new McpServer({
         name: 'sourcebot-mcp-server',
         version: SOURCEBOT_VERSION,
@@ -35,6 +36,7 @@ export async function createMcpServer(): Promise<McpServer> {
 
     const toolContext: ToolContext = {
         source: 'sourcebot-mcp-server',
+        userId: options?.userId,
     }
 
     registerMcpTool(server, grepDefinition, toolContext);
@@ -57,6 +59,11 @@ export async function createMcpServer(): Promise<McpServer> {
         },
         async () => {
             const models = await getConfiguredLanguageModelsInfo();
+            captureEvent('tool_used', {
+                toolName: 'list_language_models',
+                source: 'sourcebot-mcp-server',
+                success: true,
+            }, { distinctId: options?.userId });
             return { content: [{ type: "text", text: JSON.stringify(models) }] };
         }
     );
@@ -101,11 +108,22 @@ export async function createMcpServer(): Promise<McpServer> {
                 });
 
                 if (isServiceError(result)) {
+                    captureEvent('tool_used', {
+                        toolName: 'ask_codebase',
+                        source: 'sourcebot-mcp-server',
+                        success: false,
+                    }, { distinctId: options?.userId });
                     return {
                         content: [{ type: "text", text: `Failed to ask codebase: ${result.message}` }],
                     };
                 }
 
+                captureEvent('tool_used', {
+                    toolName: 'ask_codebase',
+                    source: 'sourcebot-mcp-server',
+                    success: true,
+                }, { distinctId: options?.userId });
+
                 const formattedResponse = dedent`
                 ${result.answer}
 

packages/web/src/features/tools/adapters.ts

@@ -1,6 +1,7 @@
 import { tool } from "ai";
 import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
 import { z } from "zod";
+import { captureEvent } from "@/lib/posthog";
 import { ToolContext, ToolDefinition } from "./types";
 
 export function toVercelAITool<TName extends string, TShape extends z.ZodRawShape, TMetadata>(
@@ -11,7 +12,21 @@ export function toVercelAITool<TName extends string, TShape extends z.ZodRawShap
         description: def.description,
         inputSchema: def.inputSchema,
         title: def.title,
-        execute: (input) => def.execute(input, context),
+        execute: async (input) => {
+            let success = true;
+            try {
+                return await def.execute(input, context);
+            } catch (error) {
+                success = false;
+                throw error;
+            } finally {
+                captureEvent('tool_used', {
+                    toolName: def.name,
+                    source: context.source ?? 'unknown',
+                    success,
+                }, { distinctId: context.userId });
+            }
+        },
         toModelOutput: ({ output }) => ({
             type: "content",
             value: [{ type: "text", text: output.output }],
@@ -38,13 +53,21 @@ export function registerMcpTool<TName extends string, TShape extends z.ZodRawSha
             },
         },
         async (input) => {
+            let success = true;
             try {
                 const parsed = def.inputSchema.parse(input);
                 const result = await def.execute(parsed, context);
                 return { content: [{ type: "text" as const, text: result.output }] };
             } catch (error) {
+                success = false;
                 const message = error instanceof Error ? error.message : String(error);
                 return { content: [{ type: "text" as const, text: `Tool "${def.name}" failed: ${message}` }], isError: true };
+            } finally {
+                captureEvent('tool_used', {
+                    toolName: def.name,
+                    source: context.source ?? 'unknown',
+                    success,
+                }, { distinctId: context.userId });
             }
         },
     );

packages/web/src/features/tools/types.ts

@@ -17,6 +17,8 @@ export type Source = z.infer<typeof sourceSchema>;
 export interface ToolContext {
     source?: string;
     selectedRepos?: string[];
+    /** User ID for telemetry attribution. When set, tool_used events will be attributed to this user. */
+    userId?: string;
 }
 
 export interface ToolDefinition<

packages/web/src/lib/apiHandler.ts

@@ -47,9 +47,7 @@ export function apiHandler<H extends AnyHandler>(
             const source = request.headers.get('X-Sourcebot-Client-Source') ?? 'unknown';
 
             // Fire and forget - don't await to avoid blocking the request
-            captureEvent('api_request', { path, method, source }).catch(() => {
-                // Silently ignore tracking errors
-            });
+            captureEvent('api_request', { path, method, source });
         }
 
         // Call the original handler with all arguments