The SDK for browser agents

AI that uses the browser like humans.

Sign in once, keep the session, and pull structured data out the other side.

import { localBrowser, Stagehand } from "@browserbasehq/stagehand";
import { z } from "zod/v4";

// Cookies persist in ./browser-data, so the next run starts already signed in
const browser = await localBrowser.launch({ userDataDir: "./browser-data" });
const stagehand = await Stagehand.create({
  browser,
  model: { modelName: "openai/gpt-5.4-mini", apiKey: process.env.OPENAI_API_KEY },
});

const [page] = await browser.context.pages();
await page.goto("https://app.example.com/login");

// observe() returns real selectors, so credentials never reach the model
const { data: email } = await stagehand.observe("find the email input");
const { data: password } = await stagehand.observe("find the password input");
await page.locator(email[0].selector).fill(process.env.APP_EMAIL!);
await page.locator(password[0].selector).fill(process.env.APP_PASSWORD!);

// act() self-heals when the site redesigns its form
await stagehand.act("click the sign in button");
await stagehand.act("open the billing page");

// extract() returns schema-validated data
const { data } = await stagehand.extract(
  "extract every invoice in the table",
  z.object({
    invoices: z.array(z.object({ number: z.string(), amount: z.number(), paid: z.boolean() })),
  }),
);

console.log(data.invoices);

await stagehand.close();
await browser.close();

import asyncio
import os

from pydantic import BaseModel
from stagehand import Stagehand, local_browser


class Invoice(BaseModel):
    number: str
    amount: float
    paid: bool


class Invoices(BaseModel):
    invoices: list[Invoice]


async def main() -> None:
    # Cookies persist in ./browser-data, so the next run starts already signed in
    browser = await local_browser.launch(user_data_dir="./browser-data")
    try:
        stagehand = await Stagehand.create(
            browser=browser,
            model="openai/gpt-5.4-mini",
            model_api_key=os.environ["OPENAI_API_KEY"],
        )
        try:
            page = (await browser.context.pages())[0]
            await page.goto("https://app.example.com/login")

            # observe() returns real selectors, so credentials never reach the model
            email = await stagehand.observe("find the email input")
            password = await stagehand.observe("find the password input")
            await page.locator(email.data[0].selector).fill(os.environ["APP_EMAIL"])
            await page.locator(password.data[0].selector).fill(os.environ["APP_PASSWORD"])

            # act() self-heals when the site redesigns its form
            await stagehand.act("click the sign in button")
            await stagehand.act("open the billing page")

            # extract() returns schema-validated data
            result = await stagehand.extract(
                "extract every invoice in the table",
                Invoices,
            )
            print(result.data.invoices)
        finally:
            await stagehand.close()
    finally:
        await browser.close()


asyncio.run(main())

package main

import (
	"context"
	"errors"
	"fmt"
	"log"
	"os"

	stagehand "github.com/browserbase/stagehand/packages/sdk-go/v4"
)

type invoice struct {
	Number string  `json:"number"`
	Amount float64 `json:"amount"`
	Paid   bool    `json:"paid"`
}

type invoices struct {
	Invoices []invoice `json:"invoices"`
}

func main() {
	if err := run(context.Background()); err != nil {
		log.Fatal(err)
	}
}

func run(ctx context.Context) (err error) {
	// Cookies persist in ./browser-data, so the next run starts already signed in
	browser, err := stagehand.LaunchLocalBrowser(ctx, &stagehand.LocalBrowserLaunchOptions{
		UserDataDir: "./browser-data",
	})
	if err != nil {
		return err
	}
	defer func() { err = errors.Join(err, browser.Close(ctx)) }()

	modelAPIKey := os.Getenv("OPENAI_API_KEY")
	client, err := stagehand.Create(ctx, stagehand.CreateOptions{
		Browser: browser,
		Model: &stagehand.ModelConfig{
			ModelName: "openai/gpt-5.4-mini",
			APIKey:    &modelAPIKey,
		},
	})
	if err != nil {
		return err
	}
	defer func() { err = errors.Join(err, client.Close(ctx)) }()

	browserContext, err := browser.Context()
	if err != nil {
		return err
	}
	pages, err := browserContext.Pages(ctx)
	if err != nil {
		return err
	}
	page := pages[0]
	if _, err := page.Goto(ctx, "https://app.example.com/login", nil); err != nil {
		return err
	}

	// Observe returns real selectors, so credentials never reach the model
	emailInstruction := "find the email input"
	email, err := client.Observe(ctx, &emailInstruction, nil)
	if err != nil {
		return err
	}
	if err := page.Locator(email.Data[0].Selector).Fill(ctx, os.Getenv("APP_EMAIL")); err != nil {
		return err
	}

	passwordInstruction := "find the password input"
	password, err := client.Observe(ctx, &passwordInstruction, nil)
	if err != nil {
		return err
	}
	if err := page.Locator(password.Data[0].Selector).Fill(ctx, os.Getenv("APP_PASSWORD")); err != nil {
		return err
	}

	// Act self-heals when the site redesigns its form
	if _, err := client.Act(ctx, stagehand.ActInstruction("click the sign in button"), nil); err != nil {
		return err
	}
	if _, err := client.Act(ctx, stagehand.ActInstruction("open the billing page"), nil); err != nil {
		return err
	}

	// Extract returns data decoded into a Go type
	extracted, err := stagehand.Extract[invoices](
		ctx,
		client,
		"extract every invoice in the table",
		nil,
	)
	if err != nil {
		return err
	}
	fmt.Println(extracted.Data.Invoices)

	return nil
}

Install

pnpm add @browserbasehq/stagehand 'zod@~4.4.3'

pip install stagehand

go get github.com/browserbase/stagehand/packages/sdk-go/[email protected]

Local runs need Chrome installed. Full setup: Quickstart.

Why Stagehand

Run it on Browserbase

Point the same script at Browserbase and get 2x faster execution than Playwright cloud equivalent browsers. Configure the Model Gateway so you never wire up a provider, and enable server-side caching to cache repeated actions.

import { browserbase, Stagehand } from "@browserbasehq/stagehand";

const browser = await browserbase.launch({ apiKey: process.env.BROWSERBASE_API_KEY! });

// No model configuration: the Model Gateway picks the cheapest model for each action
// cache: true: identical calls come back from Browserbase, no tokens spent
const stagehand = await Stagehand.create({ browser, cache: true });

import os

from stagehand import Stagehand, browserbase

browser = await browserbase.launch(api_key=os.environ["BROWSERBASE_API_KEY"])

# No model configuration: the Model Gateway picks the cheapest model for each action
# cache=True: identical calls come back from Browserbase, no tokens spent
stagehand = await Stagehand.create(browser=browser, cache=True)

browser, err := stagehand.LaunchBrowserbase(ctx, stagehand.BrowserbaseLaunchOptions{
	APIKey: os.Getenv("BROWSERBASE_API_KEY"),
})
if err != nil {
	return err
}

// No model configuration: the Model Gateway picks the cheapest model for each action
// CacheEnabled(true): identical calls come back from Browserbase, no tokens spent
cache := stagehand.CacheEnabled(true)
client, err := stagehand.Create(ctx, stagehand.CreateOptions{
	Browser: browser,
	Cache:   &cache,
})
if err != nil {
	return err
}

Verified mode, residential proxies, persistent contexts, and session recordings come with it. Get an API key and learn how to configure your browser here.

Give your coding agent a browser

The hosted Browserbase MCP server puts navigate, act, observe, and extract in any MCP client — no install, no local browser.

claude mcp add --transport http browserbase https://mcp.browserbase.com/mcp \
  --header "Authorization: Bearer $BROWSERBASE_API_KEY"

{
  "mcpServers": {
    "browserbase": {
      "url": "https://mcp.browserbase.com/mcp",
      "headers": { "Authorization": "Bearer YOUR_BROWSERBASE_API_KEY" }
    }
  }
}

Search and fetch without a browser

Fetch lets you grab the content of any URL as markdown. Search provides fast, token-efficient web search results. Both as a lightweight complement to browser sessions.

import { browserbase } from "@browserbasehq/stagehand";

const { results } = await browserbase.search({
  apiKey: process.env.BROWSERBASE_API_KEY!,
  query: "browser agent frameworks",
  numResults: 5,
});

const fetched = await browserbase.fetch({
  apiKey: process.env.BROWSERBASE_API_KEY!,
  url: results[0].url,
  format: "markdown",
});

console.log(fetched.content);

Docs and resources

Join the community

Stagehand is built in the open, and the fastest way to shape it is to show up.

• ⭐ Star this repo — it is how most people find Stagehand
• 💬 Join the Discord — questions, support, and what we are building next
• 🐛 Open an issue — bug reports are the most useful contribution
• 𝕏 Follow @stagehanddev — releases and demos

Contributing

We're focused on improving reliability, extensibility, speed, and cost, in that order. Bug fixes and small improvements are the best way to get started. For anything larger, reach out to Miguel Gonzalez or Paul Klein on Discord first so we can make sure it lands.

Stagehand is a TypeScript, Python, and Go monorepo driven by just:

git clone https://github.com/browserbase/stagehand.git
cd stagehand
just install
just generate
just build

export OPENAI_API_KEY="your-openai-api-key"
just example act # runs packages/sdk-ts/examples/act.ts

See CONTRIBUTING.md for the full TypeScript, Python, and Go setup.

Acknowledgements

We'd like to thank the following people for their major contributions to Stagehand:

• Paul Klein
• Sean McGuire
• Miguel Gonzalez
• Sameel Arif
• Thomas Katwan
• Filip Michalsky
• Anirudh Kamath
• Jeremy Press
• Navid Pour
• Nick Sweeting
• Sam Finton
• Shrey Pandya
• Shriya Lolabattu
• Alyssa Maruyama
• Amel Bajramovic

License

Licensed under the MIT License.

Copyright 2026 Browserbase, Inc.

"Stagehand" is a trademark of Browserbase, Inc.