browserbase-scraper-skill（浏览器基础抓取技巧）

Browserbase Scraper

Bypass Cloudflare and bot protection using Stagehand + Browserbase cloud browsers with AI-powered extraction.

When to Use

• Website blocks curl/fetch with Cloudflare "Just a moment..." page
• Playwright headless gets detected and blocked
• Need structured data extraction from dynamic content
• Scraping auction sites, marketplaces, or other protected pages

Prerequisites

npm install @browserbasehq/stagehand zod

Required environment variables:

• BROWSERBASE_API_KEY — from browserbase.com dashboard
• BROWSERBASE_PROJECT_ID — from browserbase.com
• GOOGLE_GENERATIVE_AI_API_KEY — for Gemini extraction (or use OpenAI)

Quick Start

import { Stagehand } from '@browserbasehq/stagehand';

const stagehand = new Stagehand({
  env: 'BROWSERBASE',
  apiKey: process.env.BROWSERBASE_API_KEY,
  projectId: process.env.BROWSERBASE_PROJECT_ID,
  model: {
    modelName: 'google/gemini-3-flash-preview',
    apiKey: process.env.GOOGLE_GENERATIVE_AI_API_KEY,
  },
});

await stagehand.init();
const page = stagehand.context.pages()[0];

// Navigate (Cloudflare bypass is automatic)
await page.goto('https://protected-site.com/search?q=term');
await page.waitForTimeout(5000); // Let page fully load

// AI-powered extraction (instruction-only works best)
const data = await stagehand.extract(`
  Extract all product listings as JSON array:
  [{ "title": "...", "price": 123, "url": "..." }]
  Return ONLY the JSON array.
`);

await stagehand.close();

Key Patterns

1. Instruction-Only Extraction (Recommended)

Schema-based extraction often returns empty. Use natural language instructions instead:

const extraction = await stagehand.extract(`
  Look at this page and extract:
  - All item titles
  - Prices as numbers
  - URLs
  Return as JSON array.
`);

2. Handle Cloudflare Delays

Sometimes the challenge takes longer:

const title = await page.title();
if (title.toLowerCase().includes('moment')) {
  await page.waitForTimeout(10000); // Wait for challenge
}

3. Scroll to Load More

Many sites lazy-load content:

for (let i = 0; i < 5; i++) {
  await page.evaluate(() => window.scrollBy(0, window.innerHeight));
  await page.waitForTimeout(800);
}

4. Parse Extraction Results

The extraction returns a string that needs parsing:

let listings = [];
try {
  const jsonMatch = extraction?.extraction?.match(/\[[\s\S]*\]/);
  if (jsonMatch) listings = JSON.parse(jsonMatch[0]);
} catch (e) {
  console.log('Parse error:', e.message);
}

Browserbase Free Tier Limits

• 1 concurrent session — cron jobs can conflict with interactive use
• Sessions auto-close after inactivity
• Use stagehand.close() to release session immediately

Cron Integration

For scheduled scraping, use OpenClaw cron with isolated sessions:

openclaw cron add \
  --name "Daily Scrape" \
  --cron "0 6 * * *" \
  --session isolated \
  --message "Run: node ~/scripts/scraper.js"

Troubleshooting

Example: Full Scraper

See scripts/example_scraper.js for a complete working example.