Handle nyx WS message types (message, new, stop, ping)

- Accept {type: 'message', content} format from nyx
- Handle 'new' (create fresh session), 'stop' (cancel pipeline)
- Ignore 'ping', 'auth', 'connect' (auth via query params)
- Send 'ready' after session_info on WS connect

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

agent/api.py

@@ -232,11 +232,14 @@ def register_routes(app):
         runtime.update_identity(user_claims, origin)
         runtime.attach_ws(ws)
 
-        # Tell client which session they're on
+        # Tell client which session they're on + ready signal
         try:
             await ws.send_text(json.dumps({
                 "type": "session_info", "session_id": runtime.session_id,
-                "graph": runtime.graph.get("name", "unknown")}))
+                "graph": runtime.graph.get("name", "unknown"),
+                "history_len": len(runtime.history)}))
+            await ws.send_text(json.dumps({
+                "type": "ready", "session_id": runtime.session_id}))
         except Exception:
             pass
 
@@ -244,9 +247,19 @@ def register_routes(app):
             while True:
                 data = await ws.receive_text()
                 msg = json.loads(data)
+                msg_type = msg.get("type", "")
                 rt = _sessions.get(runtime.session_id, runtime)
+
+                # Ping — keep-alive, no processing
+                if msg_type == "ping":
+                    continue
+
+                # Auth message from nyx — already authed via query param, ignore
+                if msg_type in ("auth", "connect"):
+                    continue
+
                 try:
-                    if msg.get("type") == "action":
+                    if msg_type == "action":
                         action = msg.get("action", "unknown")
                         data_payload = msg.get("data")
                         if hasattr(rt, 'use_frames') and rt.use_frames:
@@ -256,12 +269,46 @@ def register_routes(app):
                             await rt.handle_message(action_text)
                         else:
                             await rt.handle_action(action, data_payload)
-                    elif msg.get("type") == "cancel_process":
+
+                    elif msg_type == "cancel_process":
                         rt.process_manager.cancel(msg.get("pid", 0))
+
+                    elif msg_type == "new":
+                        # New session requested
+                        rt.detach_ws()
+                        new_rt = await _get_or_create_session(
+                            user_claims=user_claims, origin=origin)
+                        new_rt.attach_ws(ws)
+                        runtime = new_rt
+                        rt = new_rt
+                        await ws.send_text(json.dumps({
+                            "type": "session_info", "session_id": rt.session_id,
+                            "graph": rt.graph.get("name", "unknown"),
+                            "history_len": 0}))
+                        await ws.send_text(json.dumps({"type": "cleared"}))
+                        continue
+
+                    elif msg_type == "stop":
+                        # Cancel running pipeline
+                        if _pipeline_task and not _pipeline_task.done():
+                            _pipeline_task.cancel()
+                        continue
+
+                    elif msg_type == "message":
+                        # nyx format: {type: 'message', content: '...'}
+                        text = msg.get("content", "").strip()
+                        if text:
+                            await rt.handle_message(text, dashboard=msg.get("dashboard"))
+
                     else:
-                        await rt.handle_message(msg.get("text", ""), dashboard=msg.get("dashboard"))
+                        # Legacy/assay format: {text: '...', dashboard: [...]}
-                    # Auto-save after each message
+                        text = msg.get("text", "").strip()
+                        if text:
+                            await rt.handle_message(text, dashboard=msg.get("dashboard"))
+
+                    # Auto-save after each processed message
                     asyncio.create_task(_save_session(rt))
+
                 except Exception as e:
                     import traceback
                     log.error(f"[ws] handler error: {e}\n{traceback.format_exc()}")