Browserbase Create

Create Automation Skill

Guide Claude through creating new browser automation scripts using the stagehand CLI.

When to Use

Use this skill when:

• User wants to automate a website task
• User needs to scrape data from a site
• User wants to create a Browserbase Function
• Starting from scratch on a new automation

Workflow

1. Understand the Goal

Ask clarifying questions:

• What website/URL are you automating?
• What's the end goal (extract data, submit forms, monitor changes)?
• Does it require authentication?
• Should this run on a schedule or on-demand?

2. Explore the Site Interactively

Start a local browser session to understand the site structure:

stagehand session create --local
stagehand goto https://example.com

Use snapshot to understand the DOM:

stagehand snapshot

Take screenshots to see the visual layout:

stagehand screenshot -o exploration.png

3. Identify Key Elements

For each step of the automation, identify:

• Selectors for interactive elements
• Wait conditions needed
• Data to extract

Use the accessibility tree refs to understand element relationships:

[@0-5] button: "Submit"
[@0-6] textbox: "Email"
[@0-7] textbox: "Password"

4. Test Interactions Manually

Before writing code, verify each step works:

stagehand fill @0-6 "test@example.com"
stagehand fill @0-7 "password123"
stagehand click @0-5
stagehand wait networkidle
stagehand snapshot

5. Enable Network Capture (if needed)

For API-based automations or debugging:

stagehand network on
# perform actions
stagehand network list
stagehand network show 0

6. Create the Function

Once you understand the flow, create a full function project:

stagehand fn init my-automation
cd my-automation

This creates a complete project with:

• package.json with dependencies
• .env with credentials (from ~/.stagehand/config.json if available)
• tsconfig.json
• index.ts template

Edit index.ts with your automation logic:

import { defineFn } from "@browserbasehq/sdk-functions";
import { chromium } from "playwright-core";

defineFn("my-automation", async (context) => {
  const { session } = context;
  const browser = await chromium.connectOverCDP(session.connectUrl);
  const page = browser.contexts()[0]!.pages()[0]!;

  // Your automation steps here
  await page.goto("https://example.com");
  await page.fill('input[name="email"]', context.params.email);
  await page.click('button[type="submit"]');
  
  // Extract and return data
  const result = await page.textContent('.result');
  return { success: true, result };
});

7. Test Locally

Start the local development server:

pnpm bb dev index.ts
# or: stagehand fn dev index.ts

Then invoke locally via curl:

curl -X POST http://127.0.0.1:14113/v1/functions/my-automation/invoke \
  -H "Content-Type: application/json" \
  -d '{"params": {"email": "test@example.com"}}'

8. Deploy to Browserbase

When ready for production:

pnpm bb publish index.ts
# or: stagehand fn publish index.ts

9. Test Production

Invoke the deployed function:

stagehand fn invoke <function-id> -p '{"email": "test@example.com"}'

Best Practices

Selectors

• Prefer data attributes (data-testid) over CSS classes
• Use text content as fallback (text=Submit)
• Avoid fragile selectors like nth-child

Waiting

• Always wait for navigation/network after clicks
• Use waitForSelector for dynamic content
• Set reasonable timeouts

Error Handling

• Wrap risky operations in try/catch
• Return structured error information
• Log intermediate steps for debugging

Data Extraction

• Use page.evaluate() for complex extraction
• Validate extracted data before returning
• Handle missing elements gracefully

Example: E-commerce Price Monitor

defineFn("price-monitor", async (context) => {
  const { session, params } = context;
  const browser = await chromium.connectOverCDP(session.connectUrl);
  const page = browser.contexts()[0]!.pages()[0]!;

  await page.goto(params.productUrl);
  await page.waitForSelector('.price');

  const price = await page.evaluate(() => {
    const el = document.querySelector('.price');
    return el?.textContent?.replace(/[^0-9.]/g, '');
  });

  return {
    url: params.productUrl,
    price: parseFloat(price || '0'),
    timestamp: new Date().toISOString(),
  };
});