browserbase/stagehand

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
}

pip install stagehand

go get github.com/browserbase/stagehand/packages/sdk-go/v4@v4.0.0

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
}

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