Quick Start

import asyncio
from langchain_anthropic import ChatAnthropic
from langchain_core.tools import tool

from langchain_adk import LlmAgent, Runner, InMemorySessionService
from langchain_adk.events.event import Event, EventType

@tool
def get_weather(city: str) -> str:
    """Get the current weather for a city."""
    return f"The weather in {city} is sunny and 22 degrees."

agent = LlmAgent(
    name="WeatherAgent",
    llm=ChatAnthropic(model="claude-haiku-4-5-20251001"),
    tools=[get_weather],
    instructions="You are a helpful weather assistant.",
)

runner = Runner(
    agent=agent,
    app_name="demo",
    session_service=InMemorySessionService(),
)

async def main():
    async for event in runner.astream(
        user_id="user-1",
        session_id="session-1",
        new_message="What's the weather in Copenhagen and Berlin?",
    ):
        if event.is_final_response():
            print(event.text)

asyncio.run(main())