feat: 添加 tools 节点实现

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-08 01:41:06 +08:00
parent 527d7a0b1d
commit ce4d7515d9
1 changed files with 113 additions and 0 deletions
--- a/backend/app/main_graph/nodes/tools.py
+++ b/backend/app/main_graph/nodes/tools.py
@@ -0,0 +1,113 @@
+"""
+Tools 节点 - 负责执行 tool_calls
+"""
+
+from typing import Dict, Any, Optional, List
+from langchain_core.runnables.config import RunnableConfig
+from langchain_core.messages import AIMessage, ToolMessage
+
+from backend.app.main_graph.state import AgentState
+from backend.app.logger import info, error, debug
+from backend.app.tools import ALL_TOOLS
+from backend.app.agent.stream_context import get_stream_queue
+
+
+async def tools_node(state: AgentState, config: Optional[RunnableConfig] = None) -> Dict[str, Any]:
+    """
+    Tools 节点：执行 AIMessage.tool_calls，返回 ToolMessage 列表
+
+    职责：
+    1. 获取最后一条 AIMessage 的 tool_calls
+    2. 遍历执行每个工具
+    3. 记录历史（tool_call_history, tool_result_history）
+    4. 更新步数 current_step += 1
+    5. 发送工具开始/结束事件
+    """
+    queue = get_stream_queue()
+    is_streaming = queue is not None
+
+    # 获取最后一条 AIMessage
+    last_message = state.messages[-1]
+    if not isinstance(last_message, AIMessage) or not last_message.tool_calls:
+        info("[Tools] 没有工具调用，跳过")
+        return {}
+
+    tool_calls = last_message.tool_calls
+    info(f"[Tools] 执行 {len(tool_calls)} 个工具调用")
+
+    # 获取历史记录
+    tool_call_history: List[dict] = list(getattr(state, "tool_call_history", []))
+    tool_result_history: List[str] = list(getattr(state, "tool_result_history", []))
+    tools_used: List[str] = list(getattr(state, "tools_used", []))
+
+    tool_messages = []
+
+    for tc in tool_calls:
+        tool_name = tc["name"]
+        tool_args = tc["args"]
+        tool_id = tc["id"]
+
+        tools_used.append(tool_name)
+
+        # 发送工具开始事件
+        if is_streaming:
+            await queue.put({
+                "type": "custom",
+                "data": {
+                    "type": "tool_start",
+                    "tool": tool_name,
+                    "args": tool_args,
+                    "id": tool_id
+                }
+            })
+
+        # 查找并执行工具
+        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)
+                    debug(f"[Tools] 工具 {tool_name} 执行成功")
+                except Exception as e:
+                    tool_result = f"工具调用出错: {str(e)}"
+                    error(f"[Tools] 工具 {tool_name} 调用出错: {e}")
+                break
+
+        if not tool_found:
+            tool_result = f"未找到工具: {tool_name}"
+            error(f"[Tools] 未找到工具: {tool_name}")
+
+        # 发送工具结束事件
+        if is_streaming:
+            await queue.put({
+                "type": "custom",
+                "data": {
+                    "type": "tool_end",
+                    "tool": tool_name,
+                    "id": tool_id,
+                    "result": str(tool_result)
+                }
+            })
+
+        # 记录历史
+        tool_call_history.append({"name": tool_name, "args": tool_args})
+        tool_result_history.append(str(tool_result))
+
+        # 创建 ToolMessage
+        tool_messages.append(
+            ToolMessage(content=str(tool_result), tool_call_id=tool_id, name=tool_name)
+        )
+
+    # 更新步数
+    current_step = getattr(state, "current_step", 0) + 1
+
+    return {
+        "messages": tool_messages,
+        "current_step": current_step,
+        "tool_call_history": tool_call_history,
+        "tool_result_history": tool_result_history,
+        "tools_used": tools_used,
+    }