feat: message persistence, traceability and empty response auto-retry

src/agentkit/server/app.py

@@ -680,6 +680,9 @@ def create_app(
     from agentkit.server.routes.portal import _conversation_store
     _conversation_store.set_session_manager(app.state.session_manager)
 
+    # Restore conversation history from persistent store
+    await _conversation_store.restore_from_store()
+
     # Initialize evolution store if configured
     if server_config and hasattr(server_config, "evolution") and server_config.evolution:
         try:

src/agentkit/server/routes/portal.py

@@ -117,6 +117,41 @@ class ConversationStore:
         """Set or update the session manager for persistence."""
         self._session_manager = sm
 
+    async def restore_from_store(self) -> None:
+        """Restore recent conversations from SessionManager on startup.
+
+        Loads the most recent sessions and their messages so that
+        ConversationStore is populated after a server restart.
+        """
+        if self._session_manager is None:
+            return
+        try:
+            sessions = await self._session_manager.list_sessions(limit=self._max)
+            for session in sessions:
+                sid = session.session_id
+                if sid in self._conversations:
+                    continue
+                # Reconstruct Conversation from persisted session
+                conv = Conversation(
+                    id=sid,
+                    created_at=session.created_at,
+                    updated_at=session.updated_at,
+                )
+                messages = await self._session_manager.get_messages(sid)
+                for msg in messages:
+                    conv.messages.append(ChatMessage(
+                        role=msg.role.value,
+                        content=msg.content,
+                        timestamp=msg.created_at,
+                        metadata=msg.metadata,
+                    ))
+                self._conversations[sid] = conv
+            logger.info(
+                f"Restored {len(self._conversations)} conversations from SessionManager"
+            )
+        except Exception as e:
+            logger.warning(f"Failed to restore conversations from SessionManager: {e}")
+
     def get_or_create(self, conversation_id: str | None = None) -> Conversation:
         if conversation_id and conversation_id in self._conversations:
             conv = self._conversations[conversation_id]
@@ -277,6 +312,7 @@ class ChatRequest(BaseModel):
 class ChatResponse(BaseModel):
     conversation_id: str
     message: str
+    timestamp: str = ""
     matched_skill: str | None = None
     routing_method: str | None = None
     confidence: float | None = None
@@ -459,6 +495,7 @@ async def chat(request: ChatRequest, req: Request, _auth: None = Depends(_verify
     return ChatResponse(
         conversation_id=conv.id,
         message=response_text,
+        timestamp=datetime.now(timezone.utc).isoformat(),
         matched_skill=matched_skill,
         routing_method=routing_method,
         confidence=confidence,
@@ -640,9 +677,9 @@ def _derive_conversation_title(conv: Conversation) -> str:
 async def get_conversation(
     conversation_id: str, limit: int = 50, _auth: None = Depends(_verify_api_key)
 ):
-    """Get conversation history."""
-    if conversation_id not in _conversation_store._conversations:
-        raise HTTPException(status_code=404, detail=f"Conversation '{conversation_id}' not found")
+    """Get conversation history, with fallback to SessionManager for persisted data."""
+    # Try in-memory first
+    if conversation_id in _conversation_store._conversations:
         conv = _conversation_store._conversations[conversation_id]
         history = _conversation_store.get_history(conversation_id, limit=limit)
         return {
@@ -662,6 +699,42 @@ async def get_conversation(
             "updated_at": conv.updated_at.isoformat(),
         }
 
+    # Fallback: load from SessionManager (persistent store)
+    sm = _conversation_store._session_manager
+    if sm is not None:
+        try:
+            session = await sm.get_session(conversation_id)
+            if session is not None:
+                messages = await sm.get_messages(conversation_id, limit=limit)
+                return {
+                    "id": session.session_id,
+                    "title": _derive_title_from_messages(messages),
+                    "messages": [
+                        {
+                            "id": f"{session.session_id}-{i}",
+                            "role": m.role.value,
+                            "content": m.content,
+                            "timestamp": m.created_at.isoformat(),
+                            "metadata": m.metadata,
+                        }
+                        for i, m in enumerate(messages)
+                    ],
+                    "created_at": session.created_at.isoformat(),
+                    "updated_at": session.updated_at.isoformat(),
+                }
+        except Exception as e:
+            logger.warning(f"Failed to load conversation from SessionManager: {e}")
+
+    raise HTTPException(status_code=404, detail=f"Conversation '{conversation_id}' not found")
+
+
+def _derive_title_from_messages(messages: list) -> str:
+    """Derive title from a list of Message objects (SessionManager format)."""
+    for msg in messages:
+        if msg.role.value == "user" and msg.content:
+            return msg.content[:20] + ("..." if len(msg.content) > 20 else "")
+    return "对话"
+
 
 @router.websocket("/portal/ws")
 async def portal_websocket(websocket: WebSocket):