Build a web browsing agent

Stagehand gives AI agents powerful tools to control a browser completely autonomously. Watch below as a Stagehand agent autonomously navigates to a URL, takes actions on the page, and extracts structured data to answer a question. There’s quite a few ways to build an agent with Stagehand. Let’s look at a few of them.

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Stagehand MCP

The above example is a Claude agent that uses Stagehand to control a browser. At this time of writing, multimodal tool calling is only supported in Claude 3.5/3.7 Sonnet. This means Claude is intelligent enough to know when to request a browser screenshot, and it can then use that screenshot to make decisions about what actions to take next.

What’s really interesting about this is that the agent is able to reason about the browser state and take actions separate from one another! Claude is able to reason about the browser state, while Stagehand is able to take actions on the page with GPT-4o-mini or a computer use model. Stagehand is even smart enough to know when to use GPT-4o-mini and when to use a computer use model, i.e. on iframe detection.

We’ve found great success from having Claude as the “Trajectory” agent calling Stagehand tools when it sees fit! While MCP is really nascent, we’re excited to see where it goes.

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Stagehand + Computer Use Models

Stagehand lets you leverage powerful computer use APIs from OpenAI and Anthropic with just one line of code.

await page.goto("https://github.com/browserbase/stagehand");

// Create a Computer Use agent with just one line of code!
const agent = stagehand.agent({
	provider: "openai",
	model: "computer-use-preview"
});

// Use the agent to execute a task
const result = await agent.execute("Extract the top contributor's username");
console.log(result);

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Sequential Tool Calling (Open Operator)

In January 2025, Browserbase released Open Operator. Open Operator is able to reason about the browser state and take actions accordingly to accomplish larger tasks like “order me a pizza”. It works by calling Stagehand tools in sequence:

1. If there’s no URL, go to a default URL.
2. Examine the browser state. Ask an LLM to reason about what to do next.
3. Use page.act() to execute the LLM-suggested action.
4. Repeat

Incorporating Open Operator into your browser automation is as easy as adding a single line of code:

await stagehand.page.goto("https://github.com/browserbase/stagehand");

// Open Operator will use the default LLM from Stagehand config
const operator = stagehand.agent();
const { message, actions } = await operator.execute(
	"Extract the top contributor's username"
);

console.log(message);

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Replay the agent’s actions

You can replay the agent’s actions exactly the same way you would with a regular Stagehand agent. You can even automatically cache the actions to avoid unnecessary LLM calls on a repeated run.

Let’s use the replay function below to save the actions to a Stagehand script file, which will reproduce the same actions the agent did, with cached actions built in.

Here’s the replay output of an instruction like "Get me the stock price of NVDA":

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

export async function main({
  page,
  context,
  stagehand,
}: {
  page: Page; // Playwright Page with act, extract, and observe methods
  context: BrowserContext; // Playwright BrowserContext
  stagehand: Stagehand; // Stagehand instance
}) {
  await page.goto("https://www.google.com");

  // Replay will default to Playwright first to avoid unnecessary LLM calls!
  // If the Playwright action fails, Stagehand AI will take over and self-heal
  await page.act({
    description: "The search combobox where users can type their queries.",
    method: "fill",
    arguments: ["NVDA stock price"],
    selector:
      "xpath=/html/body[1]/div[1]/div[3]/form[1]/div[1]/div[1]/div[1]/div[1]/div[2]/textarea[1]",
  });
  await page.extract(
    "the displayed NVDA stock price in the search suggestions",
  );
  await stagehand.close();
}