Add PostHog events for chat repo tracking and UI interactions

- Track selected repos in `wa_chat_message_sent` (SaaS-only, gated on EXPERIMENT_ASK_GH_ENABLED)
- Refactor `createMessageStream` to accept pre-expanded repos instead of expanding internally
- Add `wa_chat_details_card_toggled`, `wa_chat_copy_answer_pressed`, `wa_chat_toc_toggled` events
- Add @saasOnly / @experimentonly JSDoc convention for SaaS-only properties

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: brendan-kellam

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

@@ -161,20 +161,22 @@ export const POST = apiHandler(async (request: NextRequest) => {
             // We'll capture the final messages and usage from the stream
             let finalMessages: SBChatMessage[] = [];
 
+            const expandedRepos = selectedSearchScopes.map(s => s.value);
+
             await captureEvent('wa_chat_message_sent', {
                 chatId: chat.id,
                 messageCount: 1,
+                ...(env.EXPERIMENT_ASK_GH_ENABLED === 'true' ? { selectedRepos: expandedRepos } : {}),
             });
 
             const stream = await createMessageStream({
                 chatId: chat.id,
                 messages: [userMessage],
                 selectedSearchScopes,
+                selectedRepos: expandedRepos,
                 model,
                 modelName,
                 modelProviderOptions: providerOptions,
-                orgId: org.id,
-                prisma,
                 onFinish: async ({ messages }) => {
                     finalMessages = messages;
                 },

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

@@ -10,8 +10,7 @@ import { isServiceError } from "@/lib/utils";
 import { withOptionalAuthV2 } from "@/withAuthV2";
 import { LanguageModelV2 as AISDKLanguageModelV2 } from "@ai-sdk/provider";
 import * as Sentry from "@sentry/nextjs";
-import { PrismaClient } from "@sourcebot/db";
-import { createLogger } from "@sourcebot/shared";
+import { createLogger, env } from "@sourcebot/shared";
 import { captureEvent } from "@/lib/posthog";
 import {
     createUIMessageStream,
@@ -89,20 +88,32 @@ export const POST = apiHandler(async (req: NextRequest) => {
 
             const { model, providerOptions } = await _getAISDKLanguageModelAndOptions(languageModelConfig);
 
+            const expandedRepos = (await Promise.all(selectedSearchScopes.map(async (scope) => {
+                if (scope.type === 'repo') return [scope.value];
+                if (scope.type === 'reposet') {
+                    const reposet = await prisma.searchContext.findFirst({
+                        where: { orgId: org.id, name: scope.value },
+                        include: { repos: true }
+                    });
+                    return reposet ? reposet.repos.map(r => r.name) : [];
+                }
+                return [];
+            }))).flat();
+
             await captureEvent('wa_chat_message_sent', {
                 chatId: id,
                 messageCount: messages.length,
-            });
+                ...(env.EXPERIMENT_ASK_GH_ENABLED === 'true' ? { selectedRepos: expandedRepos } : {}),
+            } );
 
             const stream = await createMessageStream({
                 chatId: id,
                 messages,
                 selectedSearchScopes,
+                selectedRepos: expandedRepos,
                 model,
                 modelName: languageModelConfig.displayName ?? languageModelConfig.model,
                 modelProviderOptions: providerOptions,
-                orgId: org.id,
-                prisma,
                 onFinish: async ({ messages }) => {
                     await _updateChatMessages({ chatId: id, messages, prisma });
                 },
@@ -153,11 +164,10 @@ interface CreateMessageStreamResponseProps {
     chatId: string;
     messages: SBChatMessage[];
     selectedSearchScopes: SearchScope[];
+    selectedRepos: string[];
     model: AISDKLanguageModelV2;
     modelName: string;
     modelProviderOptions?: Record<string, Record<string, JSONValue>>;
-    orgId: number;
-    prisma: PrismaClient;
     onFinish: UIMessageStreamOnFinishCallback<SBChatMessage>;
     onError: (error: unknown) => string;
 }
@@ -166,11 +176,10 @@ export const createMessageStream = async ({
     chatId,
     messages,
     selectedSearchScopes,
+    selectedRepos,
     model,
     modelName,
     modelProviderOptions,
-    orgId,
-    prisma,
     onFinish,
     onError,
 }: CreateMessageStreamResponseProps) => {
@@ -211,36 +220,12 @@ export const createMessageStream = async ({
 
             const startTime = new Date();
 
-            const expandedRepos = (await Promise.all(selectedSearchScopes.map(async (scope) => {
-                if (scope.type === 'repo') {
-                    return [scope.value];
-                }
-
-                if (scope.type === 'reposet') {
-                    const reposet = await prisma.searchContext.findFirst({
-                        where: {
-                            orgId,
-                            name: scope.value
-                        },
-                        include: {
-                            repos: true
-                        }
-                    });
-
-                    if (reposet) {
-                        return reposet.repos.map(repo => repo.name);
-                    }
-                }
-
-                return [];
-            }))).flat()
-
             const researchStream = await createAgentStream({
                 model,
                 providerOptions: modelProviderOptions,
                 inputMessages: messageHistory,
                 inputSources: sources,
-                selectedRepos: expandedRepos,
+                selectedRepos,
                 onWriteSource: (source) => {
                     writer.write({
                         type: 'data-source',

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

@@ -57,8 +57,9 @@ const AnswerCardComponent = forwardRef<HTMLDivElement, AnswerCardProps>(({
         toast({
             description: "✅ Copied to clipboard",
         });
+        captureEvent('wa_chat_copy_answer_pressed', { chatId });
         return true;
-    }, [answerText, toast]);
+    }, [answerText, chatId, captureEvent, toast]);
 
     const onFeedback = useCallback(async (feedbackType: 'like' | 'dislike') => {
         setIsSubmittingFeedback(true);
@@ -128,7 +129,10 @@ const AnswerCardComponent = forwardRef<HTMLDivElement, AnswerCardProps>(({
                                         <Toggle
                                             className="h-6 w-6 px-3 min-w-6 text-muted-foreground"
                                             pressed={isTOCButtonToggled}
-                                            onPressedChange={setIsTOCButtonToggled}
+                                            onPressedChange={(next) => {
+                                                setIsTOCButtonToggled(next);
+                                                captureEvent('wa_chat_toc_toggled', { chatId, isExpanded: next });
+                                            }}
                                         >
                                             <TableOfContentsIcon className="h-3 w-3" />
                                         </Toggle>

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

@@ -349,6 +349,7 @@ const ChatThreadListItemComponent = forwardRef<HTMLDivElement, ChatThreadListIte
                         )}
 
                         <DetailsCard
+                            chatId={chatId}
                             isExpanded={isDetailsPanelExpanded}
                             onExpandedChanged={onExpandDetailsPanel}
                             isThinking={isThinking}

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

@@ -7,7 +7,8 @@ import { Skeleton } from '@/components/ui/skeleton';
 import { Tooltip, TooltipContent, TooltipTrigger } from '@/components/ui/tooltip';
 import { cn } from '@/lib/utils';
 import { Brain, ChevronDown, ChevronRight, Clock, InfoIcon, Loader2, List, ScanSearchIcon, Zap } from 'lucide-react';
-import { memo } from 'react';
+import { memo, useCallback } from 'react';
+import useCaptureEvent from '@/hooks/useCaptureEvent';
 import { MarkdownRenderer } from './markdownRenderer';
 import { FindSymbolDefinitionsToolComponent } from './tools/findSymbolDefinitionsToolComponent';
 import { FindSymbolReferencesToolComponent } from './tools/findSymbolReferencesToolComponent';
@@ -21,6 +22,7 @@ import isEqual from "fast-deep-equal/react";
 
 
 interface DetailsCardProps {
+    chatId: string;
     isExpanded: boolean;
     onExpandedChanged: (isExpanded: boolean) => void;
     isThinking: boolean;
@@ -30,16 +32,24 @@ interface DetailsCardProps {
 }
 
 const DetailsCardComponent = ({
+    chatId,
     isExpanded,
     onExpandedChanged,
     isThinking,
     isStreaming,
     metadata,
     thinkingSteps,
 }: DetailsCardProps) => {
+    const captureEvent = useCaptureEvent();
+
+    const handleExpandedChanged = useCallback((next: boolean) => {
+        captureEvent('wa_chat_details_card_toggled', { chatId, isExpanded: next });
+        onExpandedChanged(next);
+    }, [chatId, captureEvent, onExpandedChanged]);
+
     return (
         <Card className="mb-4">
-            <Collapsible open={isExpanded} onOpenChange={onExpandedChanged}>
+            <Collapsible open={isExpanded} onOpenChange={handleExpandedChanged}>
                 <CollapsibleTrigger asChild>
                     <CardContent
                         className={cn("p-3 cursor-pointer hover:bg-muted", {

packages/web/src/lib/posthogEvents.ts

@@ -157,6 +157,12 @@ export type PosthogEventMap = {
     wa_chat_message_sent: {
         chatId: string,
         messageCount: number,
+        /**
+         * @note this field will only be populated when
+         * the EXPERIMENT_ASK_GH_ENABLED environment variable
+         * is set to true.
+         */
+        selectedRepos?: string[],
     },
     wa_chat_tool_used: {
         chatId: string,
@@ -210,6 +216,17 @@ export type PosthogEventMap = {
     wa_chat_deleted: {
         chatId: string,
     },
+    wa_chat_details_card_toggled: {
+        chatId: string,
+        isExpanded: boolean,
+    },
+    wa_chat_copy_answer_pressed: {
+        chatId: string,
+    },
+    wa_chat_toc_toggled: {
+        chatId: string,
+        isExpanded: boolean,
+    },
     //////////////////////////////////////////////////////////////////
     wa_demo_docs_link_pressed: {},
     wa_demo_search_example_card_pressed: {