agent-browser-stealth

Anti-detection browser automation built on Playwright. Launches Chromium with layered stealth to evade bot detection on protected sites.

Architecture

agent-browser-stealth
└── stealth-launch.js    # Playwright + CDP stealth wrapper
    ├── Removes navigator.webdriver
    ├── Spoofs Canvas/WebGL fingerprints
    ├── Masks chrome.runtime
    ├── Patches Permissions API
    ├── Hides automation CSS flags
    └── Preserves full Playwright functionality

Commands

# Launch and navigate
node scripts/stealth-launch.js open https://example.com

# Get interactive elements (ref-based)
node scripts/stealth-launch.js snapshot
# → Returns refs e1, e2, e3... with element metadata

# Interact
node scripts/stealth-launch.js click e3
node scripts/stealth-launch.js fill e2 "text to fill"
node scripts/stealth-launch.js type e2 "typed slowly"
node scripts/stealth-launch.js press Enter

# Inspect
node scripts/stealth-launch.js screenshot [path]
node scripts/stealth-launch.js get text e1
node scripts/stealth-launch.js get attr e5 href
node scripts/stealth-launch.js get value e2

# Close
node scripts/stealth-launch.js close

Snapshot Refs

snapshot returns numbered refs (e1, e2, ...) — use these for subsequent interactions:

1. [a] "Sign In" → /login
2. [input] placeholder="Email"
3. [input] type=password
4. [button] "Submit"

Then:

node scripts/stealth-launch.js click e1    # click Sign In
node scripts/stealth-launch.js fill e2 "user@example.com"
node scripts/stealth-launch.js fill e3 "password"
node scripts/stealth-launch.js click e4      # Submit

Stealth Layers

| Layer | Technique | |-------|-----------| | WebDriver Flag | Object.defineProperty(navigator, 'webdriver', { get: () => undefined }) | | Chrome Runtime | chrome.runtime nullified | | Canvas Fingerprint | getImageData returns noise instead of real data | | WebGL Vendor/Renderer | Spoofed to Intel Iris OpenGL Engine | | Permissions API | Returns granted for notifications/geolocation | | getComputedStyle | Animations/transition stripped | | Viewport | Randomized within 1280-1330 × 900-950 |

Installation

npm install -g playwright
npx playwright install chromium

The skill uses Playwright as a local dependency via npx — no global install of stealth plugins needed.

Session Persistence

For login persistence, use Playwright's built-in storageState:

// In scripts/stealth-session.js — save auth after login
import { chromium } from 'playwright';

const browser = await chromium.launch({ 
  headless: true,
  args: ['--disable-blink-features=AutomationControlled', '--no-sandbox']
});
const page = await browser.newPage();
// ... perform login ...
await page.context().storageState({ path: 'auth.json' });
// Next run:
const browser = await chromium.launch({ headless: true });
const context = await browser.newContext({ storageState: 'auth.json' });

Anti-Detection Testing

Test stealth effectiveness:

node scripts/stealth-launch.js open https://bot.sannysoft.com
node scripts/stealth-launch.js snapshot
# All checks should show green/undetected

Limitations

• Cloudflare JS Challenge: May require headed mode + manual solve
• CAPTCHAs: Requires external solver (2Captcha, etc.) — not built in
• Very aggressive sites: May need proxy rotation (residential proxies)

Examples

Login to a Protected Site

node scripts/stealth-launch.js open https://target-site.com/login
node scripts/stealth-launch.js snapshot
node scripts/stealth-launch.js fill e1 "email@example.com"
node scripts/stealth-launch.js fill e2 "password"
node scripts/stealth-launch.js click e3
node scripts/stealth-launch.js screenshot
node scripts/stealth-launch.js close

Scrape Dynamic Content

node scripts/stealth-launch.js open https://news.site.com
node scripts/stealth-launch.js snapshot
# Identify article refs, then extract
node scripts/stealth-launch.js get html e5
node scripts/stealth-launch.js close

Stealth vs agent-browser

| Feature | agent-browser | agent-browser-stealth | |---------|--------------|-----------------------| | Anti-detection | ❌ None | ✅ 8 layers | | Fingerprint spoofing | ❌ None | ✅ Canvas + WebGL | | CDP-based | ✅ Native Rust | ✅ Playwright | | Session isolation | ✅ | ✅ | | Complexity | Lightweight | Slightly heavier | | Best for | General automation | Protected sites |