121 lines
3.9 KiB
Python
121 lines
3.9 KiB
Python
"""MCP Client - 调用外部 MCP 工具服务器"""
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import logging
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from typing import Any
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import httpx
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from agentkit.mcp.transport import HTTPTransport, Transport
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from agentkit.tools.base import Tool
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logger = logging.getLogger(__name__)
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class MCPClient:
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"""MCP Client - 连接外部 MCP Server 并调用工具
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支持两种模式：
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1. 通过 Transport 层发送 JSON-RPC 请求（推荐）
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2. 直接 HTTP 调用（向后兼容）
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"""
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def __init__(
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self,
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server_url: str,
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timeout: int = 30,
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transport: Transport | None = None,
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):
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self._server_url = server_url.rstrip("/")
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self._timeout = timeout
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self._tools_cache: list[dict] | None = None
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self._transport = transport
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@classmethod
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def from_transport(cls, transport: Transport) -> "MCPClient":
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"""从 Transport 实例创建 MCPClient"""
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if isinstance(transport, HTTPTransport):
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server_url = transport._endpoint
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else:
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server_url = ""
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return cls(server_url=server_url, transport=transport)
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async def list_tools(self) -> list[dict]:
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"""列出远程 MCP Server 上的工具"""
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if self._transport is not None:
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if not self._transport.is_connected:
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await self._transport.connect()
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result = await self._transport.send_request("tools/list")
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tools = result.get("tools", []) if isinstance(result, dict) else []
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self._tools_cache = tools
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return self._tools_cache
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async with httpx.AsyncClient(timeout=self._timeout) as client:
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response = await client.get(f"{self._server_url}/tools/list")
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response.raise_for_status()
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data = response.json()
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self._tools_cache = data.get("tools", [])
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return self._tools_cache
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async def call_tool(self, tool_name: str, arguments: dict) -> dict:
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"""调用远程 MCP 工具"""
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if self._transport is not None:
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if not self._transport.is_connected:
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await self._transport.connect()
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return await self._transport.send_request(
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"tools/call",
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params={"name": tool_name, "arguments": arguments},
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)
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async with httpx.AsyncClient(timeout=self._timeout) as client:
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response = await client.post(
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f"{self._server_url}/tools/call",
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json={"name": tool_name, "arguments": arguments},
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)
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response.raise_for_status()
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return response.json()
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def as_tool(self, tool_name: str, description: str = "") -> "MCPTool":
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"""将远程 MCP 工具包装为本地 Tool 对象"""
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return MCPTool(
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name=tool_name,
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description=description,
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client=self,
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)
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class MCPTool(Tool):
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"""MCP 工具 - 通过 MCP Client 调用远程工具"""
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def __init__(
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self,
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name: str,
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description: str,
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client: MCPClient,
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input_schema: dict[str, Any] | None = None,
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output_schema: dict[str, Any] | None = None,
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version: str = "1.0.0",
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tags: list[str] | None = None,
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):
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super().__init__(
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name=name,
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description=description,
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input_schema=input_schema,
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output_schema=output_schema,
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version=version,
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tags=tags or ["mcp"],
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)
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self._client = client
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async def execute(self, **kwargs) -> dict:
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result = await self._client.call_tool(self.name, kwargs)
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# 解析 MCP 响应格式
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if "content" in result:
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for item in result["content"]:
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if item.get("type") == "text":
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import json
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try:
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return json.loads(item["text"])
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except json.JSONDecodeError:
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return {"result": item["text"]}
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return result
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