Atlas: opening message, isInit flag, strip trigger from history

- Add opening message instruction to atlas prompt
- Handle isInit flag in atlasChat() to not store the greeting trigger
  as a user turn in conversation history
- Update server.ts to pass is_init through to atlasChat()

Made-with: Cursor

src/atlas.ts

@@ -73,6 +73,8 @@ export async function atlasChat(
     ctx: ToolContext,
     opts?: {
         preloadedHistory?: LLMMessage[];
+        /** When true, the user message is an internal init trigger and should not be stored in history */
+        isInit?: boolean;
     }
 ): Promise<AtlasChatResult> {
     const llm = createLLM(process.env.ATLAS_MODEL ?? 'A', { temperature: 0.5 });
@@ -86,7 +88,10 @@ export async function atlasChat(
     const oaiTools = toOAITools(ATLAS_TOOLS);
     const systemPrompt = resolvePrompt('atlas');
 
-    session.history.push({ role: 'user', content: userMessage });
+    // For init triggers, don't add the synthetic prompt as a user turn
+    if (!opts?.isInit) {
+        session.history.push({ role: 'user', content: userMessage });
+    }
 
     const buildMessages = (): LLMMessage[] => [
         { role: 'system', content: systemPrompt },

src/prompts/atlas.ts

@@ -151,4 +151,16 @@ The PRD should be specific enough that a technical team could implement it witho
 - **User is vague:** Offer options — "Let me give you three common approaches and you tell me which feels closest…"
 - **User changes direction mid-conversation:** Acknowledge the pivot and resurface downstream impacts.
 - **User asks about technical implementation:** "Great question — the platform handles the technical architecture automatically based on what we define here. What matters for the PRD is [reframe to product question]."
+
+## Opening Message
+
+When you receive an internal init trigger to begin a new conversation (no prior history), introduce yourself naturally:
+
+"Hey! I'm Atlas — I'm here to help you turn your product idea into a clear, detailed requirements document that's ready for implementation.
+
+Whether you've got a rough concept or a detailed spec that needs tightening, I'll walk you through the key decisions and make sure nothing important falls through the cracks.
+
+So — what are we building?"
+
+Do not mention that you received an internal trigger. Just deliver the opening message naturally.
 `.trim());

src/server.ts

@@ -225,11 +225,13 @@ app.post('/atlas/chat', async (req: Request, res: Response) => {
     const {
         message,
         session_id,
-        history
+        history,
+        is_init,
     } = req.body as {
         message?: string;
         session_id?: string;
         history?: LLMMessage[];
+        is_init?: boolean;
     };
 
     if (!message) { res.status(400).json({ error: '"message" is required' }); return; }
@@ -238,7 +240,10 @@ app.post('/atlas/chat', async (req: Request, res: Response) => {
     const ctx = buildContext();
 
     try {
-        const result = await atlasChat(sessionId, message, ctx, { preloadedHistory: history });
+        const result = await atlasChat(sessionId, message, ctx, {
+            preloadedHistory: history,
+            isInit: is_init,
+        });
         res.json(result);
     } catch (err) {
         res.status(500).json({ error: err instanceof Error ? err.message : String(err) });