refactor(web): rename distinctId to userId in ToolContext

The field carries a user ID, not a PostHog-specific concept. The
captureEvent options parameter remains distinctId since that's the
PostHog term, but the application-level interfaces use userId.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: msukkari

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

@@ -112,7 +112,7 @@ export const POST = apiHandler(async (req: NextRequest) => {
                 modelName: languageModelConfig.displayName ?? languageModelConfig.model,
                 modelProviderOptions: providerOptions,
                 modelTemperature: temperature,
-                distinctId: user?.id,
+                userId: user?.id,
                 onFinish: async ({ messages }) => {
                     await updateChatMessages({ chatId: id, messages, prisma });
                 },

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

@@ -43,8 +43,8 @@ interface CreateMessageStreamResponseProps {
     modelProviderOptions?: Record<string, Record<string, JSONValue>>;
     modelTemperature?: number;
     metadata?: Partial<SBChatMessageMetadata>;
-    /** PostHog distinct ID for telemetry attribution on tool_used events. */
-    distinctId?: string;
+    /** User ID for telemetry attribution on tool_used events. */
+    userId?: string;
 }
 
 export const createMessageStream = async ({
@@ -58,7 +58,7 @@ export const createMessageStream = async ({
     modelTemperature,
     onFinish,
     onError,
-    distinctId,
+    userId,
 }: CreateMessageStreamResponseProps) => {
     const latestMessage = messages[messages.length - 1];
     const sources = latestMessage.parts
@@ -104,7 +104,7 @@ export const createMessageStream = async ({
                 inputMessages: messageHistory,
                 inputSources: sources,
                 selectedRepos,
-                distinctId,
+                userId,
                 onWriteSource: (source) => {
                     writer.write({
                         type: 'data-source',
@@ -158,7 +158,7 @@ interface AgentOptions {
     onWriteSource: (source: Source) => void;
     traceId: string;
     chatId: string;
-    distinctId?: string;
+    userId?: string;
 }
 
 const createAgentStream = async ({
@@ -171,7 +171,7 @@ const createAgentStream = async ({
     onWriteSource,
     traceId,
     chatId,
-    distinctId,
+    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');
@@ -208,7 +208,7 @@ const createAgentStream = async ({
         providerOptions,
         messages: inputMessages,
         system: systemPrompt,
-        tools: createTools({ source: 'sourcebot-ask-agent', selectedRepos, distinctId }),
+        tools: createTools({ source: 'sourcebot-ask-agent', selectedRepos, userId }),
         temperature: temperature ?? env.SOURCEBOT_CHAT_MODEL_TEMPERATURE,
         stopWhen: [
             stepCountIsGTE(env.SOURCEBOT_CHAT_MAX_STEP_COUNT),

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

@@ -159,7 +159,7 @@ export const askCodebase = (params: AskCodebaseParams): Promise<AskCodebaseResul
                 modelName,
                 modelProviderOptions: providerOptions,
                 modelTemperature: temperature,
-                distinctId: user?.id,
+                userId: user?.id,
                 onFinish: async ({ messages }) => {
                     finalMessages = messages;
                 },

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

@@ -37,7 +37,7 @@ export async function createMcpServer(options?: { userId?: string }): Promise<Mc
 
     const toolContext: ToolContext = {
         source: 'sourcebot-mcp-server',
-        distinctId: options?.userId,
+        userId: options?.userId,
     }
 
     registerMcpTool(server, grepDefinition, toolContext);

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

@@ -25,7 +25,7 @@ export function toVercelAITool<TName extends string, TShape extends z.ZodRawShap
                     toolName: def.name,
                     source: context.source ?? 'unknown',
                     success,
-                }, { distinctId: context.distinctId }).catch((error) => {
+                }, { distinctId: context.userId }).catch((error) => {
                     logger.warn(`Failed to capture tool_used event for ${def.name}:`, error);
                 });
             }
@@ -63,7 +63,7 @@ export function registerMcpTool<TName extends string, TShape extends z.ZodRawSha
                     toolName: def.name,
                     source: context.source ?? 'unknown',
                     success: true,
-                }, { distinctId: context.distinctId }).catch((error) => {
+                }, { distinctId: context.userId }).catch((error) => {
                     logger.warn(`Failed to capture tool_used event for ${def.name}:`, error);
                 });
                 return { content: [{ type: "text" as const, text: result.output }] };
@@ -72,7 +72,7 @@ export function registerMcpTool<TName extends string, TShape extends z.ZodRawSha
                     toolName: def.name,
                     source: context.source ?? 'unknown',
                     success: false,
-                }, { distinctId: context.distinctId }).catch((error) => {
+                }, { distinctId: context.userId }).catch((error) => {
                     logger.warn(`Failed to capture tool_used event for ${def.name}:`, error);
                 });
                 const message = error instanceof Error ? error.message : String(error);

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

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