from langchain.agents import create_agent
from langchain_community.chat_models.tongyi import ChatTongyi
from langchain_core.tools import tool

@tool(description="查询天气")
def get_weather():
    return "晴天"


agent = create_agent(
    model=ChatTongyi(model="qwen3-max"),
    tools=[get_weather],
    system_prompt="你是一个聊天助手，可以回答用户问题"
)

res = agent.invoke(
    {
        "messages": [
            {"role": "user", "content": "明天深圳的天气如何"},
        ]
    }
)

for msg in res["messages"]:
    print(f"{type(msg).__name__}: {msg.content}")