Observability for Pydantic AI

import asyncio

from pydantic_ai import Agent, RunContext
from lmnr import Laminar, observe

Laminar.initialize()

flight_agent = Agent(
    "openai:gpt-5-mini",
    system_prompt="You are a flight search specialist. Return one recommended flight.",
)

@flight_agent.tool_plain
def search_flights(origin: str, destination: str, date: str) -> str:
    return f"Options {origin}->{destination} on {date}: DL204 Delta $412, UA880 United $438."

hotel_agent = Agent(
    "openai:gpt-5-mini",
    system_prompt="You are a hotel booking specialist. Return one recommended hotel.",
)

@hotel_agent.tool_plain
def search_hotels(city: str, check_in: str, check_out: str) -> str:
    return f"Hotels in {city}: Kimpton Gray $285/nt, Hyatt Place $199/nt."

concierge = Agent(
    "openai:gpt-5-mini",
    system_prompt="You are a travel concierge. Use the tools to book a flight and a hotel.",
)

@concierge.tool
async def book_flight(ctx: RunContext, origin: str, destination: str, date: str) -> str:
    result = await flight_agent.run(f"Find a flight from {origin} to {destination} on {date}.")
    return result.output

@concierge.tool
async def book_hotel(ctx: RunContext, city: str, check_in: str, check_out: str) -> str:
    result = await hotel_agent.run(f"Find a hotel in {city} from {check_in} to {check_out}.")
    return result.output

@observe(name="plan-trip")
async def main():
    result = await concierge.run(
        "Plan a trip from JFK to Chicago on 2026-05-12, returning 2026-05-15."
    )
    print(result.output)

if __name__ == "__main__":
    asyncio.run(main())