agent功能开发增加MCP后端

mcp_server.py

@@ -1679,6 +1679,9 @@ async def agent_chat(request: AgentChatRequest):
             ensure_ascii=False
         )
 
+        # 将 plan 转换为 JSON 字符串（ES 中 plan 字段是 text 类型）
+        plan_json = json.dumps(response.plan.dict(), ensure_ascii=False) if response.plan else None
+
         es_client.save_chat_message(
             session_id=session_id,
             user_id=request.user_id or "anonymous",
@@ -1686,7 +1689,7 @@ async def agent_chat(request: AgentChatRequest):
             user_avatar=request.user_avatar or "",
             message_type="assistant",
             message=response.final_summary,  # 使用 final_summary 而不是 final_answer
-            plan=response.plan.dict() if response.plan else None,  # 转换为字典
+            plan=plan_json,  # 传递 JSON 字符串而不是字典
             steps=steps_json,
         )
     except Exception as e: