stagehand-py 0.1.9

Python SDK for Stagehand

An AI web browsing framework focused on simplicity and extensibility.

NOTE: This is a Python SDK for Stagehand. The original implementation is in TypeScript and is available here.

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Stagehand is the easiest way to build browser automations with AI-powered interactions. It extends the Playwright API with three powerful AI primitives:

• act — Instruct the AI to perform actions (e.g. click a button or scroll).
• extract — Extract and validate data from a page using a JSON schema (generated either manually or via a Pydantic model).
• observe — Get natural language interpretations to, for example, identify selectors or elements from the DOM.

Pydantic Schemas

Stagehand uses Pydantic models to define the options for AI commands:

• ActOptions
  The ActOptions model takes an action field that tells the AI what to do on the page, plus optional fields such as useVision and variables:

  from stagehand.schemas import ActOptions
  
  # Example:
  await page.act(ActOptions(action="click on the 'Quickstart' button"))
  

• ObserveOptions
  The ObserveOptions model lets you find elements on the page using natural language. The onlyVisible option helps limit the results:

  from stagehand.schemas import ObserveOptions
  
  # Example:
  await page.observe(ObserveOptions(instruction="find the button labeled 'News'", onlyVisible=True))
  

• ExtractOptions
  The ExtractOptions model extracts structured data from the page. Pass your instructions and a schema defining your expected data format. Note: If you are using a Pydantic model for the schema, call its .model_json_schema() method to ensure JSON serializability.

  from stagehand.schemas import ExtractOptions
  from pydantic import BaseModel
  
  class DescriptionSchema(BaseModel):
      description: str
  
  # Example:
  data = await page.extract(
      ExtractOptions(
          instruction="extract the description of the page",
          schemaDefinition=DescriptionSchema.model_json_schema()
      )
  )
  description = data.get("description") if isinstance(data, dict) else data.description
  

Why?

Stagehand adds determinism to otherwise unpredictable agents.

While there's no limit to what you could instruct Stagehand to do, our primitives allow you to control how much you want to leave to an AI. It works best when your code is a sequence of atomic actions. Instead of writing a single script for a single website, Stagehand allows you to write durable, self-healing, and repeatable web automation workflows that actually work.

[!NOTE] Stagehand is currently available as an early release, and we're actively seeking feedback from the community. Please join our Slack community to stay updated on the latest developments and provide feedback.

Installation

Install the Python package via pip:

pip install stagehand-py

Environment Variables

Before running your script, set the following environment variables:

export BROWSERBASE_API_KEY="your-api-key"
export BROWSERBASE_PROJECT_ID="your-project-id"
export OPENAI_API_KEY="your-openai-api-key"  # or your preferred model's API key
export STAGEHAND_SERVER_URL="url-of-stagehand-server"

Quickstart

Below is a minimal example to get started with Stagehand using the new schema-based options:

import asyncio
import os
from stagehand.client import Stagehand
from stagehand.schemas import ActOptions, ExtractOptions
from pydantic import BaseModel
from dotenv import load_dotenv

load_dotenv()

class DescriptionSchema(BaseModel):
    description: str

async def main():
    # Create a Stagehand client - it will automatically create a new session if needed
    stagehand = Stagehand(
        model_name="gpt-4o",  # Optional: defaults are available from the server
    )

    # Initialize Stagehand and create a new session
    await stagehand.init()
    print(f"Created new session: {stagehand.session_id}")

    # Navigate to a webpage using local Playwright controls
    await stagehand.page.goto("https://www.example.com")
    print("Navigation complete.")

    # Perform an action using the AI (e.g. simulate a button click)
    await stagehand.page.act(ActOptions(action="click on the 'Quickstart' button"))

    # Extract data from the page with schema validation
    data = await stagehand.page.extract(
        ExtractOptions(
            instruction="extract the description of the page",
            schemaDefinition=DescriptionSchema.model_json_schema()
        )
    )
    description = data.get("description") if isinstance(data, dict) else data.description
    print("Extracted description:", description)

    await stagehand.close()

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

Running Evaluations

To test all evaluations, run the following command in your terminal:

python evals/run_all_evals.py

This script will dynamically discover and execute every evaluation module within the evals directory and print the results for each.

More Examples

For further examples, check out the scripts in the examples/ directory:

1. examples/example.py: Demonstrates combined server-side/page navigation with AI-based actions.
2. examples/extract-example.py: Shows how to use the extract functionality with a JSON schema or a Pydantic model.
3. examples/observe-example.py: Demonstrates the observe functionality to get natural-language readings of the page.

Configuration

Stagehand can be configured via environment variables or through a StagehandConfig object. Available configuration options include:

• stagehand_server_url: URL of the Stagehand API server.
• browserbase_api_key: Your Browserbase API key (BROWSERBASE_API_KEY).
• browserbase_project_id: Your Browserbase project ID (BROWSERBASE_PROJECT_ID).
• model_api_key: Your model API key (e.g. OpenAI, Anthropic, etc.) (MODEL_API_KEY).
• verbose: Verbosity level (default: 1).
• model_name: Optional model name for the AI.
• dom_settle_timeout_ms: Additional time (in ms) to have the DOM settle.
• debug_dom: Enable debug mode for DOM operations.

Example using a unified configuration:

from stagehand.config import StagehandConfig
import os

config = StagehandConfig(
    env="BROWSERBASE" if os.getenv("BROWSERBASE_API_KEY") and os.getenv("BROWSERBASE_PROJECT_ID") else "LOCAL",
    api_key=os.getenv("BROWSERBASE_API_KEY"),
    project_id=os.getenv("BROWSERBASE_PROJECT_ID"),
    debug_dom=True,
    headless=False,
    dom_settle_timeout_ms=3000,
    model_name="gpt-4o-mini",
    model_client_options={"apiKey": os.getenv("MODEL_API_KEY")}
)

Features

• AI-powered Browser Control: Execute natural language instructions over a running browser.
• Validated Data Extraction: Use JSON schemas (or Pydantic models) to extract and validate information from pages.
• Async/Await Support: Built using Python's asyncio, making it easy to build scalable web automation workflows.
• Extensible: Seamlessly extend Playwright functionality with AI enrichments.

Requirements

• Python 3.7+
• httpx
• asyncio
• pydantic
• python-dotenv (optional, for .env support)

License

MIT License (c) 2025 Browserbase, Inc.