修复状态兼容性问题: 移除 dict 解包操作

backend/app/main_graph/nodes/llm_call.py

@@ -141,7 +141,7 @@ def create_llm_call_node(llm, tools: list):
                 "has_tool_calls": has_tool_calls
             }
 
-            log_state_change("llm_call", {**state, **result}, "离开")
+            log_state_change("llm_call", state, "离开")
             return result
 
         except Exception as e:

backend/app/main_graph/nodes/tool_call.py

@@ -9,7 +9,7 @@ from langchain_core.messages import AIMessage, ToolMessage
 from app.main_graph.config import get_stream_writer
 
 # 本地模块
-from app.main_graph.state import MessagesState
+from app.main_graph.state import MainGraphState
 from app.utils.logging import log_state_change
 from app.logger import debug, info
 
@@ -26,7 +26,7 @@ def create_tool_call_node(tools_by_name: Dict[str, Any]):
 
     from langchain_core.runnables.config import RunnableConfig
 
-    async def call_tools(state: MessagesState, config: RunnableConfig) -> Dict[str, Any]:
+    async def call_tools(state: MainGraphState, config: RunnableConfig) -> Dict[str, Any]:
         """
         工具执行节点（异步方法）
 
@@ -39,7 +39,7 @@ def create_tool_call_node(tools_by_name: Dict[str, Any]):
         """
         log_state_change("tool_node", state, "进入")
 
-        last_message = state['messages'][-1]
+        last_message = state.messages[-1]
         if not isinstance(last_message, AIMessage) or not last_message.tool_calls:
             log_state_change("tool_node", state, "离开（无工具调用）")
             return {"messages": []}
@@ -75,10 +75,9 @@ def create_tool_call_node(tools_by_name: Dict[str, Any]):
                 else:
                     observation = await loop.run_in_executor(
                         None,
-                        lambda args=tool_args: tool_func.invoke(args)  # 默认参数捕获当前值
+                        lambda args=tool_args: tool_func.invoke(args)
                     )
 
-                # 字符打印
                 result_preview = str(observation).replace("\n", " ")
                 debug(f"   └─ ✅ 结果: {result_preview}")
                 results.append(ToolMessage(content=str(observation), tool_call_id=tool_id))
@@ -95,7 +94,7 @@ def create_tool_call_node(tools_by_name: Dict[str, Any]):
         info(f"🛠️  [工具调用] 执行完成，返回 {len(results)} 条 ToolMessage")
 
         result = {"messages": results}
-        log_state_change("tool_node", {**state, **result}, "离开")
+        log_state_change("tool_node", state, "离开")
         return result
 
     return call_tools