examples/features/validate_output.py

"""
Demostrate output validator.

@dev You need to add OPENAI_API_KEY to your environment variables.
"""

import os
import sys

sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))

import asyncio

from dotenv import load_dotenv
from langchain_openai import ChatOpenAI
from pydantic import BaseModel

from browser_use import ActionResult, Agent, Controller

load_dotenv()

controller = Controller()


class DoneResult(BaseModel):
	title: str
	comments: str
	hours_since_start: int


# we overwrite done() in this example to demonstrate the validator
@controller.registry.action('Done with task', param_model=DoneResult)
async def done(params: DoneResult):
	result = ActionResult(is_done=True, extracted_content=params.model_dump_json())
	print(result)
	# NOTE: this is clearly wrong - to demonstrate the validator
	return 'blablabla'


async def main():
	task = 'Go to hackernews hn and give me the top 1 post'
	model = ChatOpenAI(model='gpt-4o')
	agent = Agent(task=task, llm=model, controller=controller, validate_output=True)
	# NOTE: this should fail to demonstrate the validator
	await agent.run(max_steps=5)


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