chore(ask_sb): Add PostHog telemetry event for new chat thread creation (#418)

CHANGELOG.md

@@ -10,6 +10,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 - [ask sb] Fixed "413 content too large" error when starting a new chat with many repos selected. [#416](https://github.com/sourcebot-dev/sourcebot/pull/416)
 
+### Added
+- [ask sb] PostHog telemetry for chat thread creation. [#418](https://github.com/sourcebot-dev/sourcebot/pull/418)
+
 ## [4.6.1] - 2025-07-29
 
 ### Added

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

@@ -12,12 +12,14 @@ import { isServiceError } from "@/lib/utils";
 import { createPathWithQueryParams } from "@/lib/utils";
 import { SearchScope, SET_CHAT_STATE_SESSION_STORAGE_KEY, SetChatStatePayload } from "./types";
 import { useSessionStorage } from "usehooks-ts";
+import useCaptureEvent from "@/hooks/useCaptureEvent";
 
 export const useCreateNewChatThread = () => {
     const domain = useDomain();
     const [isLoading, setIsLoading] = useState(false);
     const { toast } = useToast();
     const router = useRouter();
+    const captureEvent = useCaptureEvent();
 
     const [, setChatState] = useSessionStorage<SetChatStatePayload | null>(SET_CHAT_STATE_SESSION_STORAGE_KEY, null);
 
@@ -38,6 +40,8 @@ export const useCreateNewChatThread = () => {
             return;
         }
 
+        captureEvent('wa_chat_thread_created', {});
+
         setChatState({
             inputMessage,
             selectedSearchScopes,
@@ -47,7 +51,7 @@ export const useCreateNewChatThread = () => {
 
         router.push(url);
         router.refresh();
-    }, [domain, router, toast, setChatState]);
+    }, [domain, router, toast, setChatState, captureEvent]);
 
     return {
         createNewChatThread,

packages/web/src/lib/posthogEvents.ts

@@ -282,6 +282,7 @@ export type PosthogEventMap = {
         chatId: string,
         messageId: string,
     },
+    wa_chat_thread_created: {},
     //////////////////////////////////////////////////////////////////
     wa_demo_docs_link_pressed: {},
     wa_demo_search_context_card_pressed: {