feat(ai): auto-title a conversation from its first user message (#1850)

The console sidebar lists conversations straight off the `ai_conversations`
rows, so an untitled conversation renders a generic "New conversation"
label — and once a user has a handful, the list is a wall of identical
rows with no way to tell them apart or find one.

Set `title` from the first USER message the moment it lands, in
`addMessage`: collapse whitespace, cap at 60 chars. Deterministic, no extra
model call. Only seeds when the conversation has no title yet and the turn
is a user turn, so the optional LLM auto-titler still overwrites it with a
nicer title when enabled, and an explicit title is never clobbered.

Tests: untitled→titled, existing-title kept, assistant-first-turn ignored,
whitespace-collapse + truncation. Suite green (23).

Co-authored-by: Jack Zhuang <277994282+os-zhuang@users.noreply.github.com>
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: 3 people

packages/services/service-ai/src/__tests__/objectql-conversation-service.test.ts

@@ -251,6 +251,33 @@ describe('ObjectQLConversationService', () => {
     expect(updated.updatedAt >= conv.updatedAt).toBe(true);
   });
 
+  it('auto-titles an untitled conversation from its first user message', async () => {
+    const conv = await service.create(); // no title
+    expect(conv.title).toBeUndefined();
+    const updated = await service.addMessage(conv.id, { role: 'user', content: 'Build me a ticketing system' });
+    expect(updated.title).toBe('Build me a ticketing system');
+  });
+
+  it('does not overwrite an existing title, and only a USER first turn seeds it', async () => {
+    const titled = await service.create({ title: 'My title' });
+    const afterUser = await service.addMessage(titled.id, { role: 'user', content: 'hello' });
+    expect(afterUser.title).toBe('My title'); // kept
+
+    const fresh = await service.create();
+    const afterAssistant = await service.addMessage(fresh.id, { role: 'assistant', content: 'hi there' });
+    expect(afterAssistant.title).toBeUndefined(); // assistant turn does not seed a title
+  });
+
+  it('collapses whitespace and truncates a long first message into the title', async () => {
+    const conv = await service.create();
+    const long = 'design   an\n  employee onboarding system with departments tasks members and a dashboard and reports';
+    const updated = await service.addMessage(conv.id, { role: 'user', content: long });
+    expect(updated.title!.length).toBeLessThanOrEqual(60);
+    expect(updated.title).not.toContain('\n');
+    expect(updated.title).toMatch(/^design an employee onboarding/);
+    expect(updated.title!.endsWith('…')).toBe(true);
+  });
+
   it('should add a tool message with toolCallId', async () => {
     const conv = await service.create();
     const msg: ModelMessage = {

packages/services/service-ai/src/conversation/objectql-conversation-service.ts

@@ -59,6 +59,16 @@ const MESSAGE_ORDER = [
  * Production environments should use this implementation to ensure
  * conversation history survives service restarts.
  */
+/**
+ * A short, single-line title derived from a user message: collapse whitespace
+ * and cap the length. Pure + deterministic (no model call).
+ */
+function firstMessageTitle(text: string, maxLength = 60): string {
+  const flat = text.replace(/\s+/g, ' ').trim();
+  if (flat.length <= maxLength) return flat;
+  return `${flat.slice(0, maxLength - 1).trimEnd()}…`;
+}
+
 export class ObjectQLConversationService implements IAIConversationService {
   private readonly engine: IDataEngine;
 
@@ -237,10 +247,22 @@ export class ObjectQLConversationService implements IAIConversationService {
       created_at: now,
     });
 
-    // Update conversation timestamp
-    await this.engine.update(CONVERSATIONS_OBJECT, { id: conversationId, updated_at: now }, {
-      where: { id: conversationId },
-    });
+    // Auto-title from the first user message. The sidebar lists conversations
+    // straight off the `ai_conversations` rows, so an untitled conversation
+    // shows a generic label — a wall of identical rows once a user has a few.
+    // The LLM auto-titler may be disabled or run a beat later; this gives every
+    // conversation a readable label the instant its first user turn lands,
+    // deterministically and with no extra model call. A nicer LLM title (when
+    // enabled) simply overwrites it.
+    const titleUpdate =
+      message.role === 'user' && !row.title && contentStr
+        ? { title: firstMessageTitle(contentStr) }
+        : {};
+    await this.engine.update(
+      CONVERSATIONS_OBJECT,
+      { id: conversationId, updated_at: now, ...titleUpdate },
+      { where: { id: conversationId } },
+    );
 
     // Return the full updated conversation
     return (await this.get(conversationId))!;