53 lines
2.0 KiB
Python
53 lines
2.0 KiB
Python
# examples/mcp_modes/direct_tool_loop.py
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import asyncio
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from langchain_core.messages import HumanMessage, ToolMessage
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from langgraph_qwen.chat_model import ChatQwenOpenAICompat
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from langgraph_qwen.mcp import load_mcp_tools
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PHASE1_SERVERS = {
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"math": {"command":"python","args":["/abs/path/to/math_server.py"],"transport":"stdio"}
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}
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PHASE2_SERVERS = {
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"weather": {"url":"http://127.0.0.1:8000/mcp/","transport":"streamable_http"}
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}
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async def main(max_steps: int = 8):
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# ★ 比如不同阶段加载不同工具集
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tools_phase1 = await load_mcp_tools(servers=PHASE1_SERVERS)
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tools_phase2 = await load_mcp_tools(servers=PHASE2_SERVERS)
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model = ChatQwenOpenAICompat(temperature=0).bind_tools(
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tools_phase1 + tools_phase2
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).bind(tool_choice="auto")
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tool_map = {t.name: t for t in (tools_phase1 + tools_phase2)}
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msgs = [HumanMessage(content="先用数学工具算 12*(3+5)，再查北京天气，最后给一句总结。")]
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for _ in range(max_steps):
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ai = await model.ainvoke(msgs)
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msgs.append(ai)
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calls = getattr(ai, "tool_calls", []) or ai.additional_kwargs.get("tool_calls", [])
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if not calls:
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break
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for call in calls:
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name, args, call_id = call.get("name"), call.get("args", {}), call.get("id") or ""
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tool = tool_map.get(name)
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if not tool:
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msgs.append(ToolMessage(tool_call_id=call_id, content=f"Unknown tool: {name}"))
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continue
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try:
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if hasattr(tool, "ainvoke"):
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out = await tool.ainvoke(args)
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else:
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out = tool.invoke(args)
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msgs.append(ToolMessage(tool_call_id=call_id, content=str(out)))
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except Exception as e:
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msgs.append(ToolMessage(tool_call_id=call_id, content=f"Error: {e}"))
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final = await model.ainvoke(msgs)
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print("=== Final ===")
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print(final.content)
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if __name__ == "__main__":
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asyncio.run(main())
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