from mcp.client.streamable_http import streamablehttp_client
from langchain.agents import create_tool_calling_agent, AgentExecutor
from langchain_core.prompts import ChatPromptTemplate
from langchain_mcp_adapters.tools import load_mcp_tools
from langchain_openai import ChatOpenAI
from mcp import ClientSession
import asyncio
from python_a2a import MCPClient, to_langchain_tool
from agent_learn.config import Config
conf = Config()
# 创建模型
llm = ChatOpenAI(base_url=conf.base_url,
api_key=conf.api_key,
model=conf.model_name,
temperature=0.1)
# 创建一个异步函数,来实现客户端的创建及使用
async def main():
# 创建MCP客户端
url = "http://localhost:8010"
mcp_client = MCPClient(server_url=url)
try:
# 获取可用的工具列表
tools = await mcp_client.get_tools()
print(f'MCP tools-->{tools}')
# 将 MCP tool 转成 LangChain 的工具
get_weather_tool = to_langchain_tool(url, "get_weather")
query_high_frequency_question = to_langchain_tool(url, "query_high_frequency_question")
tools = [get_weather_tool, query_high_frequency_question]
# 创建prompt模板
# agent_scratchpad 这个参数是agent在进行推理的时候,自动生成的,用于记录agent的推理过程。
prompt_template = ChatPromptTemplate.from_messages([
("system", "你是一个乐于助人的助手,能够调用工具回答用户问题。"),
("human", "{user_input}"),
("placeholder", "{agent_scratchpad}"),
])
# 创建agent对象
agent = create_tool_calling_agent(llm, tools, prompt_template)
# 使用agent对象创建agent执行器
agent_executor = AgentExecutor(agent=agent, tools=tools, verbose=True)
# agent调用
print("MCP客户端启动,输入'quit'退出")
while True:
# 接收用户查询
query = input("\nQuery: ").strip()
if query.lower() == "quit":
break
try:
# 发送用户查询给代理,并打印 ainvoke 指的是异步调用
response = await agent_executor.ainvoke({"user_input": query})
print(f"response-->{response}")
except Exception:
print("解析有问题")
except Exception as e:
print(f"Error: {e}")
# 启动运行
if __name__ == '__main__':
asyncio.run(main())