重构：简化流式架构，将 ReAct 循环移入 agent 节点

主要变更：
- 简化 agent_service：移除复杂双协程，只用 stream_mode=["updates"]
- stream_context：提供更清晰的 API (set_stream_queue/get_stream_queue)
- main_graph_builder：简化图结构，移除 tools 节点和条件边
- agent 节点：包含完整 ReAct 循环 + 流式 Tool Calling 拼接
- 前端：适配新的事件格式
- 添加测试文件：test_full_react_streaming.py, test_stream.py

backend/app/agent/agent_service.py

@@ -1,6 +1,6 @@
 """
-AI Agent 服务类 - 优化版本：双协程 + 结束哨兵 + 完整的取消和异常处理
-接收外部传入的 checkpointer，不负责管理连接生命周期
+AI Agent 服务类 - 完全简化版本！
+按照指南实现，不用 stream_mode="messages" 避免重复 token！
 """
 
 import json
@@ -11,11 +11,11 @@ from typing import AsyncGenerator, Dict, Any, Optional, Tuple
 from langgraph.checkpoint.serde.jsonplus import JsonPlusSerializer
 
 # 本地模块
-from ..model_services import get_cached_chat_services
-from ..main_graph.main_graph_builder import build_agent_graph
+from backend.app.model_services import get_cached_chat_services
+from backend.app.main_graph.main_graph_builder import build_agent_graph
 from backend.app.logger import debug, info, warning, error
-from ..main_graph.state import AgentState
-from .stream_context import token_queue_var
+from backend.app.main_graph.state import AgentState
+from .stream_context import set_stream_queue
 
 
 class AIAgentService:
@@ -120,125 +120,10 @@ class AIAgentService:
             "model_used": resolved_model
         }
 
-    def _serialize_value(self, value):
-        """递归将 LangChain 对象转换为可 JSON 序列化的格式"""
-        if hasattr(value, 'content'):
-            msg_type = getattr(value, 'type', 'message')
-            return {
-                "role": msg_type,
-                "content": getattr(value, 'content', ''),
-                "additional_kwargs": getattr(value, 'additional_kwargs', {}),
-                "tool_calls": getattr(value, 'tool_calls', [])
-            }
-        elif isinstance(value, dict):
-            return {k: self._serialize_value(v) for k, v in value.items()}
-        elif isinstance(value, (list, tuple)):
-            return [self._serialize_value(item) for item in value]
-        else:
-            try:
-                json.dumps(value)
-                return value
-            except (TypeError, ValueError):
-                return str(value)
-
-    async def _handle_message_chunk(
-        self, chunk: Dict[str, Any], current_node: Optional[str], tool_calls_in_progress: Dict[str, Any]
-    ) -> AsyncGenerator[Dict[str, Any], None]:
-        """处理 messages 类型的 chunk"""
-        message_chunk, metadata = chunk["data"]
-        node_name = metadata.get("langgraph_node", "unknown")
-        new_current_node = current_node
-
-        # 检测节点变化，发送节点开始事件
-        if node_name != current_node:
-            if current_node:
-                yield {"type": "node_end", "node": current_node}
-            yield {"type": "node_start", "node": node_name}
-            new_current_node = node_name
-
-        # 处理消息内容
-        token_content = getattr(message_chunk, 'content', str(message_chunk))
-        reasoning_token = ""
-        if hasattr(message_chunk, 'additional_kwargs'):
-            reasoning_token = message_chunk.additional_kwargs.get("reasoning_content", "")
-
-        # 处理思考过程
-        if reasoning_token:
-            yield {
-                "type": "llm_token",
-                "node": node_name,
-                "reasoning_token": reasoning_token
-            }
-        # 处理工具调用
-        elif hasattr(message_chunk, 'tool_calls') and message_chunk.tool_calls:
-            for tool_call in message_chunk.tool_calls:
-                tool_call_id = tool_call.get("id", "")
-                tool_name = tool_call.get("name", "")
-                tool_args = tool_call.get("args", {})
-
-                # 记录工具调用开始，避免重复
-                if tool_call_id and tool_call_id not in tool_calls_in_progress:
-                    tool_calls_in_progress[tool_call_id] = {
-                        "name": tool_name,
-                        "args": tool_args
-                    }
-                    yield {
-                        "type": "tool_call_start",
-                        "tool": tool_name,
-                        "args": tool_args,
-                        "id": tool_call_id
-                    }
-        # 处理普通 token
-        elif token_content:
-            yield {
-                "type": "llm_token",
-                "node": node_name,
-                "token": token_content,
-                "reasoning_token": reasoning_token
-            }
-
-        # 返回更新后的 current_node
-        yield {"type": "_update_state", "current_node": new_current_node}
-
-    async def _handle_updates_chunk(
-        self, chunk: Dict[str, Any], tool_calls_in_progress: Dict[str, Any], actual_model_used: str
-    ) -> AsyncGenerator[Dict[str, Any], None]:
-        """处理 updates 类型的 chunk"""
-        updates_data = chunk["data"]
-        new_actual_model = actual_model_used
-        
-        serialized_data = self._serialize_value(updates_data)
-        
-        # 检查是否有工具结果
-        if "messages" in serialized_data:
-            for msg in serialized_data["messages"]:
-                # 检测工具结果消息
-                if msg.get("role") == "tool":
-                    tool_call_id = msg.get("tool_call_id", "")
-                    tool_name = msg.get("name", "")
-                    tool_result = msg.get("content", "")
-                    
-                    if tool_call_id and tool_call_id in tool_calls_in_progress:
-                        yield {
-                            "type": "tool_call_end",
-                            "tool": tool_name,
-                            "id": tool_call_id,
-                            "result": tool_result
-                        }
-                        del tool_calls_in_progress[tool_call_id]
-        
-        yield {
-            "type": "state_update",
-            "data": serialized_data
-        }
-        
-        # 返回更新后的模型
-        yield {"type": "_update_state", "actual_model_used": new_actual_model}
-
     async def process_message_stream(
         self, message: str, thread_id: str, model: str = "", user_id: str = "default_user"
     ) -> AsyncGenerator[Dict[str, Any], None]:
-        """流式处理消息 - 双协程 + 结束哨兵 + 完整取消和异常处理"""
+        """流式处理消息 - 完全简化！"""
         # 解析模型名称
         resolved_model = self._resolve_model(model)
         
@@ -246,144 +131,64 @@ class AIAgentService:
         config, input_state = self._build_invocation(message, thread_id, resolved_model, user_id)
 
         info(f"🚀 开始执行 Agent 图，指定模型: {resolved_model}")
-        current_node = None
-        tool_calls_in_progress: Dict[str, Any] = {}
         actual_model_used = resolved_model
-        full_message_content = ""
 
         # 创建 token 队列
-        token_queue = asyncio.Queue()
-        # 结束哨兵
-        SENTINEL = object()
+        queue = asyncio.Queue()
+        set_stream_queue(queue)  # 设置上下文变量
 
-        # 设置上下文变量
-        token_queue_var.set(token_queue)
-
-        # 事件和错误跟踪
-        graph_error = None
-        graph_done = asyncio.Event()
-
-        async def run_graph_task():
-            """后台任务：运行 graph.astream()"""
-            nonlocal current_node, actual_model_used, full_message_content, graph_error
+        async def run_graph():
+            """后台任务：运行 graph，只获取 updates，不要用 stream_mode="messages" 避免重复 token！"""
             try:
                 info(f"📡 开始调用 graph.astream()...")
                 
-                event_count = 0
-                
+                # 注意：只用 stream_mode=["updates"]，不要 "messages"！避免重复 token！
                 async for chunk in self.graph.astream(
                     input_state,
                     config=config,
-                    stream_mode=["messages", "updates"],
+                    stream_mode=["updates"],
                     version="v2",
                     subgraphs=True
                 ):
-                    chunk_count = 0
-                    chunk_count += 1
-                    chunk_type = chunk["type"]
-                    
-                    # 记录原始 chunk 信息（前 10 个和后 10 个）
-                    if chunk_count <= 10 or chunk_count % 50 == 0:
-                        info(f"  [{chunk_count}] chunk_type={chunk_type}, data={type(chunk.get('data'))}")
-
-                    if chunk_type == "messages":
-                        async for event in self._handle_message_chunk(
-                            chunk, current_node, tool_calls_in_progress
-                        ):
-                            if event.get("type") == "_update_state":
-                                current_node = event.get("current_node", current_node)
-                            else:
-                                event_count += 1
-                                # 记录前 10 个事件
-                                if event_count <= 10:
-                                    info(f"    → yield event #{event_count}: {event.get('type')}")
-                                
-                                # 如果是 agent 节点的 token，收集完整消息
-                                if (
-                                    event.get("type") == "llm_token"
-                                    and event.get("node") == "agent"
-                                    and "token" in event
-                                ):
-                                    full_message_content += event["token"]
-                                await token_queue.put(event)
-
-                    elif chunk_type == "updates":
-                        async for event in self._handle_updates_chunk(
-                            chunk, tool_calls_in_progress, actual_model_used
-                        ):
-                            if event.get("type") == "_update_state":
-                                actual_model_used = event.get("actual_model_used", actual_model_used)
-                            else:
-                                event_count += 1
-                                if event_count <= 10:
-                                    info(f"    → yield event #{event_count}: {event.get('type')}")
-                                await token_queue.put(event)
-
-                # 完整消息集合完成后，一次性打印
-                info(f"✅ graph.astream() 完成，共 {event_count} 个 events")
-                if full_message_content:
-                    info(f"📄 完整消息内容: {repr(full_message_content)}")
-
+                    # 可以处理一些状态更新事件，如 final_result 等
+                    await queue.put({
+                        "type": "graph_update",
+                        "data": chunk,
+                    })
             except Exception as e:
                 error(f"❌ 执行图时出错: {e}")
                 import traceback
                 error(f"📋 堆栈: {traceback.format_exc()}")
-                graph_error = e
-                await token_queue.put({
-                    "type": "error",
-                    "message": str(e)
-                })
+                await queue.put({"type": "error", "message": str(e)})
             finally:
-                # 发送结束哨兵
-                await token_queue.put(SENTINEL)
-                graph_done.set()
+                await queue.put(None)  # 结束哨兵
 
         # 启动后台任务
-        graph_task = asyncio.create_task(run_graph_task())
+        bg_task = asyncio.create_task(run_graph())
 
         try:
-            # 主协程：从队列里取事件并 yield
             while True:
-                try:
-                    # 等待队列中的事件，带超时检查任务是否完成
-                    event = await asyncio.wait_for(token_queue.get(), timeout=0.5)
-                    
-                    # 检查是否是结束哨兵
-                    if event is SENTINEL:
-                        break
-                    
-                    yield event
-                
-                except asyncio.TimeoutError:
-                    # 超时检查任务是否完成
-                    if graph_task.done():
-                        # 检查任务是否抛出异常
-                        if graph_task.exception():
-                            exc = graph_task.exception()
-                            error(f"❌ 后台任务异常: {exc}")
-                        break
-        
-        except asyncio.CancelledError:
-            info("⚠️ 流式生成被取消")
+                event = await queue.get()
+                if event is None:
+                    break
+                yield event
+
+        except GeneratorExit:
+            # 客户端断开连接，取消后台任务
+            info("⚠️ GeneratorExit，取消后台任务")
+            bg_task.cancel()
             raise
-        
         finally:
-            # 无论成功或失败，都清理资源
-            # 取消后台任务
-            if not graph_task.done():
-                info("⏹️ 取消后台任务")
-                graph_task.cancel()
+            # 保证任务被清理
+            if not bg_task.done():
+                info("⏹️ 清理后台任务")
+                bg_task.cancel()
                 try:
-                    await graph_task
+                    await bg_task
                 except asyncio.CancelledError:
                     info("✅ 后台任务已取消")
             
             # 发送结束事件，保证前端平稳关闭
-            if current_node:
-                yield {
-                    "type": "node_end",
-                    "node": current_node
-                }
             yield {
                 "type": "done",
                 "model_used": actual_model_used

backend/app/agent/stream_context.py

@@ -1,9 +1,22 @@
-"""流式上下文，用于在 LangGraph 节点和 agent_service 之间传递 token 队列"""
+"""
+流式上下文，用于在 LangGraph 节点和 agent_service 之间传递 token 队列
+清晰的 API，更易用！
+"""
 import contextvars
 import asyncio
 from typing import Optional, Any
 
-# 上下文变量：存储当前的 token 队列
-token_queue_var: contextvars.ContextVar[Optional[asyncio.Queue]] = contextvars.ContextVar(
-    "token_queue", default=None
+# 上下文变量：存储每个请求专属的 token 队列
+stream_queue_ctx: contextvars.ContextVar[Optional[asyncio.Queue]] = contextvars.ContextVar(
+    "stream_queue", default=None
 )
+
+
+def set_stream_queue(queue: asyncio.Queue) -> None:
+    """设置当前请求的队列"""
+    stream_queue_ctx.set(queue)
+
+
+def get_stream_queue() -> Optional[asyncio.Queue]:
+    """获取当前请求的队列"""
+    return stream_queue_ctx.get()

backend/app/main_graph/main_graph_builder.py

@@ -1,12 +1,12 @@
 """
-极简 Agent 主图 - 自己的节点结构，更好控制流式
+极简 Agent 主图 - 简化版本！
+因为完整的 ReAct 循环已经在 agent.py 里了！
 """
 
 from langgraph.graph import StateGraph, START, END
-from langgraph.prebuilt import ToolNode
-from ..state import AgentState
-from ..nodes.memory_trigger import memory_trigger_node, set_mem0_client
-from ..nodes.agent import create_agent_node
+from backend.app.main_graph.state import AgentState
+from backend.app.main_graph.nodes.memory_trigger import memory_trigger_node, set_mem0_client
+from backend.app.main_graph.nodes.agent import create_agent_node
 from backend.app.logger import info, warning
 from backend.app.tools import ALL_TOOLS
 
@@ -17,7 +17,7 @@ def build_agent_graph(
     max_steps: int = 10
 ):
     """
-    构建包含记忆节点的 Agent 图
+    构建简化的 Agent 图（ReAct 循环在 agent 节点内）
 
     Args:
         chat_services: 模型服务字典
@@ -51,28 +51,16 @@ def build_agent_graph(
         except Exception as e:
             info(f"[Graph Builder] 记忆节点初始化失败: {e}")
 
-    # ========== 3. 核心节点 ==========
+    # ========== 3. Agent 节点（包含完整 ReAct 循环） ==========
     llm_with_tools = primary_model.bind_tools(ALL_TOOLS)
     agent_node_fn = create_agent_node(llm_with_tools, primary_model)
-    tool_node_fn = ToolNode(ALL_TOOLS)
 
-    # ========== 4. 条件边判断函数 ==========
-    def should_continue(state: AgentState):
-        """判断是继续调用工具还是结束"""
-        messages = state.messages
-        last_message = messages[-1] if messages else None
-
-        if last_message and hasattr(last_message, 'tool_calls') and last_message.tool_calls:
-            return "tools"
-
-        return "finalize"
-
-    # ========== 5. 完成节点 ==========
+    # ========== 4. 完成节点 ==========
     async def finalize_node_simple(state: AgentState):
         info("[Finalize] 进入完成节点")
         return {}
 
-    # ========== 6. 构建图 ==========
+    # ========== 5. 构建图 ==========
     graph = StateGraph(AgentState)
 
     graph.add_node("init_state", init_state_node)
@@ -80,10 +68,9 @@ def build_agent_graph(
         graph.add_node("retrieve_memory", retrieve_memory_node)
     graph.add_node("memory_trigger", memory_trigger_node)
     graph.add_node("agent", agent_node_fn)
-    graph.add_node("tools", tool_node_fn)
     graph.add_node("finalize", finalize_node_simple)
 
-    # ========== 7. 边的连接 ==========
+    # ========== 6. 边的连接 ==========
     graph.add_edge(START, "init_state")
 
     if retrieve_memory_node:
@@ -93,18 +80,8 @@ def build_agent_graph(
         graph.add_edge("init_state", "memory_trigger")
 
     graph.add_edge("memory_trigger", "agent")
-
-    graph.add_conditional_edges(
-        "agent",
-        should_continue,
-        {
-            "tools": "tools",
-            "finalize": "finalize"
-        }
-    )
-
-    graph.add_edge("tools", "agent")
+    graph.add_edge("agent", "finalize")
     graph.add_edge("finalize", END)
 
-    info("✅ [Graph Builder] 极简 Agent 图构建完成")
+    info("✅ [Graph Builder] 简化 Agent 图构建完成（ReAct 在节点内）")
     return graph

backend/app/main_graph/nodes/agent.py

@@ -1,11 +1,15 @@
-"""Agent 节点：核心推理与工具调用"""
+"""
+Agent 节点：完整的 ReAct 循环 + 流式 Tool Calling 拼接
+完全参考指南实现！
+"""
 
-from typing import Dict, Any, Optional
-from langchain_core.messages import SystemMessage, AIMessage, AIMessageChunk
+from typing import Dict, Any, Optional, List
+from langchain_core.messages import SystemMessage, AIMessage, AIMessageChunk, ToolMessage
 from langchain_core.runnables.config import RunnableConfig
-from ..state import AgentState
+from backend.app.main_graph.state import AgentState
 from backend.app.logger import info, warning, error
-from .stream_context import token_queue_var
+from backend.app.agent.stream_context import get_stream_queue
+from backend.app.tools import ALL_TOOLS
 
 
 # 系统提示词（从 main_graph_builder.py 搬过来）
@@ -54,11 +58,12 @@ SYSTEM_PROMPT = """你是一个智能助手，可以使用多种工具完成复
 
 
 def create_agent_node(llm_with_tools, llm):
-    """创建 Agent 节点函数"""
+    """创建 Agent 节点函数，完整 ReAct 循环"""
 
     async def agent_node(state: AgentState, config: Optional[RunnableConfig] = None) -> Dict[str, Any]:
         """
-        Agent 节点：调用带工具的 LLM，处理步数限制
+        Agent 节点：完整的 ReAct 循环，带流式 token 和工具调用事件
+        兼容流式和非流式两种情况！
 
         Args:
             state: 当前状态
@@ -67,114 +72,214 @@ def create_agent_node(llm_with_tools, llm):
         Returns:
             状态更新字典
         """
-        current_step = state.get("current_step", 0)
-        info(f"[Agent] 第 {current_step} 步推理")
+        # 获取队列
+        queue = get_stream_queue()
+        is_streaming = queue is not None
+
+        # 获取当前步数
+        current_step = getattr(state, "current_step", 0)
+        max_steps = getattr(state, "max_steps", 10)
+        info(f"[Agent] 从第 {current_step} 步开始，最大步数: {max_steps}，流式: {is_streaming}")
+
+        # 组装完整消息
+        messages = [SystemMessage(content=SYSTEM_PROMPT)] + list(state.messages)
+        turn = current_step  # 轮次从当前步数开始
 
         try:
-            # 组装完整消息：系统提示 + 历史消息
-            full_messages = [SystemMessage(content=SYSTEM_PROMPT)] + state.messages
-            
-            info(f"[Agent] 消息数量: {len(full_messages)}, 最后一条: {type(full_messages[-1]).__name__}")
+            while turn < max_steps:
+                turn += 1
+                info(f"[Agent] 第 {turn} 轮思考")
 
-            # 判断是否达到步数上限
-            if current_step >= state.get("max_steps", 10):
-                info(f"[Agent] 达到步数上限 {state.get('max_steps', 10)}，强制结束，不绑定工具")
-                current_llm = llm.bind_tools([])
-            else:
-                current_llm = llm_with_tools
+                # 告诉前端：新的一轮开始（如果流式）
+                if is_streaming:
+                    await queue.put({
+                        "type": "turn_start",
+                        "turn": turn,
+                    })
 
-            info(f"[Agent] 调用带工具的 LLM...")
+                # 选择 LLM
+                if turn >= max_steps:
+                    info(f"[Agent] 达到步数上限，用不带工具的 LLM")
+                    current_llm = llm.bind_tools([])
+                else:
+                    current_llm = llm_with_tools
 
-            # 获取 token 队列
-            token_queue = token_queue_var.get()
-            if token_queue is None:
-                error("[Agent] ❌ token_queue 为 None！")
-                raise RuntimeError("token_queue 上下文变量未设置")
+                # 初始化变量
+                full_content = ""
+                full_reasoning_content = ""
+                pending_tool_calls = {}  # key: index, value: {id, name, args_str}
+                final_tool_calls = []
 
-            # 完整消息
-            full_content = ""
-            full_reasoning_content = ""
-            full_tool_calls = []
-
-            # 流式调用 LLM
-            async for chunk in current_llm.astream(full_messages):
-                if isinstance(chunk, AIMessageChunk):
-                    # 处理 content
-                    if chunk.content:
-                        full_content += chunk.content
-                        await token_queue.put({
-                            "type": "llm_token",
-                            "node": "agent",
-                            "token": chunk.content,
-                            "reasoning_token": "",
-                            "turn": current_step,
-                            "phase": "answering" if not full_tool_calls else "thinking"
-                        })
-
-                    # 处理 reasoning_content
-                    if hasattr(chunk, 'additional_kwargs') and chunk.additional_kwargs:
-                        reasoning_content = chunk.additional_kwargs.get("reasoning_content", "")
-                        if reasoning_content:
-                            full_reasoning_content += reasoning_content
-                            await token_queue.put({
-                                "type": "llm_token",
-                                "node": "agent",
-                                "token": "",
-                                "reasoning_token": reasoning_content,
-                                "turn": current_step,
-                                "phase": "thinking"
-                            })
-
-                    # 处理 tool_calls
-                    if hasattr(chunk, 'tool_calls') and chunk.tool_calls:
-                        # 合并 tool_calls
-                        for tc in chunk.tool_calls:
-                            # 查找是否已经有这个 id 的 tool_call
-                            found = False
-                            for existing_tc in full_tool_calls:
-                                if existing_tc.get("id") == tc.get("id"):
-                                    # 合并 args
-                                    existing_tc["args"] = {**existing_tc.get("args", {}), **tc.get("args", {})}
-                                    found = True
-                                    break
-                            if not found:
-                                full_tool_calls.append(tc)
-                                # 发送工具调用开始事件
-                                await token_queue.put({
-                                    "type": "tool_call_start",
-                                    "tool": tc.get("name"),
-                                    "args": tc.get("args"),
-                                    "id": tc.get("id", ""),
-                                    "turn": current_step
+                # 只有流式的时候用 astream，非流式直接用 ainvoke 更快！
+                if is_streaming:
+                    async for chunk in current_llm.astream(messages):
+                        if isinstance(chunk, AIMessageChunk):
+                            # 1. 处理文本 token
+                            if chunk.content:
+                                full_content += chunk.content
+                                await queue.put({
+                                    "type": "llm_token",
+                                    "turn": turn,
+                                    "phase": "answering",
+                                    "token": chunk.content,
+                                    "reasoning_token": ""
                                 })
 
-            # 构建完整的 AIMessage
-            response = AIMessage(
-                content=full_content,
-                tool_calls=full_tool_calls if full_tool_calls else None
-            )
+                            # 2. 处理 reasoning token
+                            if hasattr(chunk, 'additional_kwargs') and chunk.additional_kwargs:
+                                reasoning_content = chunk.additional_kwargs.get("reasoning_content", "")
+                                if reasoning_content:
+                                    full_reasoning_content += reasoning_content
+                                    await queue.put({
+                                        "type": "llm_token",
+                                        "turn": turn,
+                                        "phase": "reasoning",
+                                        "token": "",
+                                        "reasoning_token": reasoning_content
+                                    })
+
+                            # 3. 流式 Tool Calling 拼接逻辑（核心！用 tool_call_chunks！）
+                            if hasattr(chunk, 'tool_call_chunks') and chunk.tool_call_chunks:
+                                for tc_chunk in chunk.tool_call_chunks:
+                                    idx = tc_chunk.get("index", 0)
+                                    if idx not in pending_tool_calls:
+                                        pending_tool_calls[idx] = {
+                                            "id": "",
+                                            "name": "",
+                                            "args": ""  # 初始化为字符串
+                                        }
+
+                                    if tc_chunk.get("id"):
+                                        pending_tool_calls[idx]["id"] += tc_chunk["id"]
+                                    if tc_chunk.get("name"):
+                                        pending_tool_calls[idx]["name"] += tc_chunk["name"]
+                                    if tc_chunk.get("args"):
+                                        args_val = tc_chunk["args"]
+                                        if isinstance(args_val, str):
+                                            pending_tool_calls[idx]["args"] += args_val
+                                        else:
+                                            import json
+                                            pending_tool_calls[idx]["args"] += json.dumps(args_val)
+                else:
+                    # 非流式，直接 ainvoke
+                    result = await current_llm.ainvoke(messages)
+                    full_content = result.content if result.content else ""
+                    if hasattr(result, 'tool_calls') and result.tool_calls:
+                        final_tool_calls = result.tool_calls
+                    if hasattr(result, 'additional_kwargs') and result.additional_kwargs:
+                        full_reasoning_content = result.additional_kwargs.get("reasoning_content", "")
+
+                # 流式调用结束后，整理最终的 tool_calls（只在流式时处理 pending！）
+                if is_streaming:
+                    for idx in sorted(pending_tool_calls.keys()):
+                        tc_data = pending_tool_calls[idx]
+                        if tc_data["name"]:  # 只有有名字的才是有效工具调用
+                            # 解析参数字符串
+                            args = {}
+                            if tc_data["args"]:
+                                try:
+                                    import json
+                                    args = json.loads(tc_data["args"])
+                                except Exception as e:
+                                    info(f"[Agent] Failed to parse args JSON: {e}, raw: {tc_data['args']}")
+                            final_tool_calls.append({
+                                "id": tc_data["id"],
+                                "name": tc_data["name"],
+                                "args": args
+                            })
+
+                # 判断是否有工具调用
+                if final_tool_calls:
+                    info(f"[Agent] 第 {turn} 轮：调用 {len(final_tool_calls)} 个工具")
+
+                    # 执行工具调用
+                    new_messages = []
+                    for tc in final_tool_calls:
+                        tool_name = tc["name"]
+                        tool_args = tc["args"]
+                        tool_id = tc["id"]
+
+                        # 发送工具开始事件（如果流式）
+                        if is_streaming:
+                            await queue.put({
+                                "type": "tool_start",
+                                "turn": turn,
+                                "tool": tool_name,
+                                "args": tool_args,
+                                "id": tool_id
+                            })
+
+                        # 找到并执行对应工具
+                        tool_result = ""
+                        tool_found = False
+                        for tool in ALL_TOOLS:
+                            if tool.name == tool_name:
+                                tool_found = True
+                                try:
+                                    tool_result = await tool.ainvoke(tool_args)
+                                except Exception as e:
+                                    tool_result = f"工具调用出错: {str(e)}"
+                                    error(f"[Agent] 工具 {tool_name} 调用出错: {e}")
+                                break
+
+                        if not tool_found:
+                            tool_result = f"未找到工具: {tool_name}"
+
+                        # 发送工具结束事件（如果流式）
+                        if is_streaming:
+                            await queue.put({
+                                "type": "tool_end",
+                                "turn": turn,
+                                "tool": tool_name,
+                                "id": tool_id,
+                                "result": str(tool_result)
+                            })
+
+                        # 构造 ToolMessage
+                        tool_msg = ToolMessage(
+                            content=str(tool_result),
+                            tool_call_id=tool_id,
+                            name=tool_name
+                        )
+                        new_messages.append(tool_msg)
+
+                    # 添加到 messages，继续下一轮
+                    messages.extend(new_messages)
+                    continue
+
+                else:
+                    # 没有工具调用，最终输出
+                    info(f"[Agent] 第 {turn} 轮：完成，无工具调用")
+                    if is_streaming:
+                        await queue.put({
+                            "type": "final_answer",
+                            "turn": turn,
+                            "content": full_content
+                        })
+                    break
+
+            # 构建完整的 AIMessage 用于状态更新
+            response_kwargs = {"content": full_content}
+            if final_tool_calls:
+                response_kwargs["tool_calls"] = final_tool_calls
+            response = AIMessage(**response_kwargs)
             if full_reasoning_content:
                 response.additional_kwargs["reasoning_content"] = full_reasoning_content
 
-            info(f"[Agent] LLM 调用成功！响应类型: {type(response).__name__}")
-            if hasattr(response, 'tool_calls') and response.tool_calls:
-                info(f"[Agent] 检测到工具调用: {[tc['name'] for tc in response.tool_calls]}")
-
             # 返回状态更新
             return {
                 "messages": [response],
-                "current_step": current_step + 1,
-                "llm_calls": state.get("llm_calls", 0) + 1
+                "current_step": turn,
+                "llm_calls": getattr(state, "llm_calls", 0) + 1
             }
 
         except Exception as e:
-            error(f"[Agent] ❌ 第 {current_step} 步推理出错: {e}")
+            error(f"[Agent] ❌ 第 {turn} 轮出错: {e}")
             import traceback
             error(f"[Agent] 堆栈: {traceback.format_exc()}")
-            # 发送错误事件
-            token_queue = token_queue_var.get()
-            if token_queue:
-                await token_queue.put({
+            # 发送错误事件（如果流式）
+            if is_streaming:
+                await queue.put({
                     "type": "error",
                     "message": str(e)
                 })

backend/app/tools/__init__.py

@@ -7,7 +7,7 @@ from typing import Optional
 from backend.app.logger import info
 
 
-# ====== RAG Pipeline（复用现有）
+# ========== RAG Pipeline（复用现有）
 _rag_pipeline = None
 
 

frontend/src/components/chat_area.py

@@ -226,7 +226,7 @@ def _handle_ai_response():
             elif event_type == "llm_token":
                 node_name = event.get("node", "unknown")
                 # 确保只处理来自 LLM 的 token，避免将工具的输出作为 token 显示
-                if node_name in ("llm_call", "fallback"):
+                if node_name in ("llm_call", "fallback", "agent"):
                     token = str(event.get("token", ""))
                     reasoning_token = str(event.get("reasoning_token", ""))
                     

tools/test/test_full_react_streaming.py

@@ -0,0 +1,104 @@
+"""
+测试新的完整 ReAct 循环架构 + 流式 Tool Calling
+"""
+
+import asyncio
+import sys
+import os
+
+sys.path.insert(0, "/root/projects/ailine/backend")
+
+from app.main_graph.main_graph_builder import build_agent_graph
+from app.model_services import get_cached_chat_services
+from app.agent.stream_context import set_stream_queue
+from app.logger import info, error
+
+
+async def test_full_react_streaming():
+    """测试完整的 ReAct 循环流式架构"""
+    info("=" * 60)
+    info("🧪 测试完整 ReAct 循环 + 流式 Tool Calling")
+    info("=" * 60)
+
+    # 1. 获取服务
+    chat_services = get_cached_chat_services()
+    info(f"✅ 加载了 {len(chat_services)} 个模型: {list(chat_services.keys())}")
+
+    # 2. 构建图
+    graph_builder = build_agent_graph(chat_services, mem0_client=None)
+    graph = graph_builder.compile()
+    info(f"✅ 图构建完成")
+
+    # 3. 创建队列
+    queue = asyncio.Queue()
+    set_stream_queue(queue)
+
+    # 4. 定义后台任务
+    async def run_graph():
+        try:
+            input_state = {
+                "messages": [
+                    {"role": "user", "content": "你好，请介绍一下你自己"}
+                ],
+                "user_id": "test_user",
+            }
+            async for chunk in graph.astream(
+                input_state,
+                stream_mode=["updates"],
+                version="v2"
+            ):
+                await queue.put({
+                    "type": "graph_update",
+                    "data": chunk,
+                })
+        except Exception as e:
+            error(f"❌ 图执行出错: {e}")
+            import traceback
+            error(f"📋 堆栈: {traceback.format_exc()}")
+            await queue.put({"type": "error", "message": str(e)})
+        finally:
+            await queue.put(None)
+
+    # 5. 启动后台任务并处理事件
+    bg_task = asyncio.create_task(run_graph())
+
+    info("\n📡 开始接收流式事件:\n")
+    try:
+        while True:
+            event = await queue.get()
+            if event is None:
+                break
+            if event["type"] == "llm_token":
+                if event["token"]:
+                    print(event["token"], end="")
+                if event["reasoning_token"]:
+                    print(f"<think>{event['reasoning_token']}</think>", end="")
+            elif event["type"] == "turn_start":
+                print(f"\n===== Turn {event['turn']} 开始 =====")
+            elif event["type"] == "tool_start":
+                print(f"\n🔧 工具调用: {event['tool']}")
+            elif event["type"] == "tool_end":
+                print(f"\n✅ 工具调用完成")
+            elif event["type"] == "final_answer":
+                print(f"\n📝 最终答案")
+            elif event["type"] == "graph_update":
+                # 忽略 update 事件，只关心 agent 节点发的事件
+                pass
+            else:
+                print(f"\n📋 其他事件: {event}")
+
+        print("\n✅ 流式测试完成")
+        return True
+
+    except Exception as e:
+        error(f"❌ 测试出错: {e}")
+        import traceback
+        error(f"📋 堆栈: {traceback.format_exc()}")
+        return False
+    finally:
+        if not bg_task.done():
+            bg_task.cancel()
+
+
+if __name__ == "__main__":
+    asyncio.run(test_full_react_streaming())

tools/test/test_stream.py

@@ -0,0 +1,79 @@
+#!/usr/bin/env python3
+"""测试后端流式接口，看看是否真的有流式输出"""
+
+import asyncio
+import aiohttp
+import json
+
+BACKEND_URL = "http://localhost:8079/chat/stream"
+
+
+async def test_stream():
+    print("=" * 60)
+    print("🧪 测试后端流式接口")
+    print("=" * 60)
+
+    async with aiohttp.ClientSession() as session:
+        payload = {
+            "message": "你好，请简单介绍一下自己",
+            "thread_id": "test-thread-001",
+            "model": "zhipu",
+            "user_id": "test-user"
+        }
+
+        print(f"\n📤 发送请求: {json.dumps(payload, ensure_ascii=False)}")
+
+        try:
+            async with session.post(BACKEND_URL, json=payload) as response:
+                print(f"\n✅ 响应状态: {response.status}")
+                print(f"\n📥 开始接收流式响应...\n")
+
+                event_count = 0
+                token_count = 0
+
+                async for line in response.content:
+                    line = line.decode('utf-8').strip()
+                    if line:
+                        if line.startswith("data: "):
+                            data_str = line[6:]
+                            if data_str == "[DONE]":
+                                print("\n🏁 收到 [DONE] 事件")
+                                break
+                            
+                            try:
+                                event = json.loads(data_str)
+                                event_count += 1
+                                print(f"  [{event_count}] {event.get('type')}")
+                                
+                                if event.get('type') == 'llm_token' and 'token' in event:
+                                    token = event['token']
+                                    token_count += 1
+                                    print(f"      → token: {repr(token)}")
+                                
+                                if event.get('type') == 'node_start':
+                                    print(f"      → node: {event.get('node')}")
+                                
+                                if event.get('type') == 'tool_call_start':
+                                    print(f"      → tool: {event.get('tool')}")
+                                
+                                if event.get('type') == 'tool_call_end':
+                                    print(f"      → tool: {event.get('tool')}")
+                                
+                                if event.get('type') == 'error':
+                                    print(f"      ❌ 错误: {event.get('message')}")
+                                
+                            except Exception as e:
+                                print(f"  ❌ 解析失败: {e}, 原始数据: {repr(data_str)}")
+                        else:
+                            print(f"  📝 原始行: {repr(line)}")
+
+                print(f"\n📊 统计: {event_count} 个事件, {token_count} 个 token")
+
+        except Exception as e:
+            print(f"\n❌ 请求异常: {e}")
+            import traceback
+            print(f"📋 堆栈: {traceback.format_exc()}")
+
+
+if __name__ == "__main__":
+    asyncio.run(test_stream())