react_agent_structured_output

react_agent_structured_output.py

from pydantic import BaseModel, Field
from typing import Literal
from langchain_core.tools import tool
from langchain_anthropic import ChatAnthropic
from langgraph.graph import MessagesState


class WeatherResponse(BaseModel):
    """Respond to the user with this"""

    temperature: float = Field(description="The temperature in fahrenheit")
    wind_directon: str = Field(
        description="The direction of the wind in abbreviated form"
    )
    wind_speed: float = Field(description="The speed of the wind in km/h")


@tool
def get_weather(city: Literal["nyc", "sf"]):
    """Use this to get weather information."""
    if city == "nyc":
        return "It is cloudy in NYC, with 5 mph winds in the North-East direction and a temperature of 70 degrees"
    elif city == "sf":
        return "It is 75 degrees and sunny in SF, with 3 mph winds in the South-East direction"
    else:
        raise AssertionError("Unknown city")


@tool(return_direct=True, response_format="content_and_artifact", args_schema=WeatherResponse)
def get_structured_response(**tool_args):
    # this will put tool args into the ToolMessage.artifact.
    # also, since the tool is marked as return_direct=True, create_react_agent will exit when it calls this tool
    return "Here is your structured response", tool_args


tools = [get_weather, get_structured_response]
model = ChatAnthropic(model="claude-3-7-sonnet-latest")
agent = create_react_agent(model, tools)