Stealth Browser: How AI Agents Bypass Bot Detection

Source: Dev.to

Problem Overview

Most AI browser automation fails immediately: Cloudflare blocks it, DataDome flags it, CAPTCHAs appear, and the agent gets stuck.

Stealth Browser Engine

Bridge ACE includes a stealth browser engine that passes bot detection. It is built on Patchright, a Playwright fork with anti‑fingerprint hardening.

When you run Playwright or Puppeteer, websites can detect automation through:

• navigator.webdriver = true
• Missing Chrome plugins and extensions
• Inconsistent navigator.userAgentData
• SwiftShader GPU (headless giveaway)
• Missing speechSynthesis voices
• WebRTC IP leaks
• Predictable mouse movements and timing

The stealth browser applies comprehensive evasions:

bridge_stealth_start(
    stealth_level='high',    # low/medium/high/paranoid
    headless=False,          # Real GPU — SwiftShader is instant detection
    disable_webrtc=True,     # Prevent IP leaks
    inject_client_hints=True, # navigator.userAgentData
    inject_speech_api=True    # speechSynthesis voices
)

What Gets Patched

• AutomationControlled flag disabled
• Client Hints injected (sec-ch-ua headers)
• Speech API mocked with realistic voices
• WebRTC IP leak protection
• Screen overrides for consistent fingerprint
• performance.memory spoofed
• Timing jitter — human‑like delays between actions

Browser Automation Levels

Bridge ACE provides three levels of browser automation:

Fast, Reliable (Internal Tools & APIs)

bridge_browser_navigate(url='...')
bridge_browser_click(selector='#submit')

Passes most bot detection for protected websites.

Stealth Navigation

bridge_stealth_goto(url='https://protected-site.com')
bridge_stealth_fill(selector='input', value='...')

Attach to User’s Real Chrome

Inherits all sessions, cookies, and extensions.

bridge_cdp_connect(port=9222)
bridge_cdp_navigate(url='https://linkedin.com')
# Full access to logged‑in sessions

CAPTCHA Solving

When stealth is not enough and a CAPTCHA appears:

bridge_captcha_solve(
    captcha_type='recaptcha_v2',
    website_url='https://example.com',
    website_key='site-key-here'
)

Supports reCAPTCHA v2/v3, hCaptcha, Cloudflare Turnstile, and FunCaptcha via CAPSolver, 2Captcha, or Anti‑Captcha.

Repository

All three browser engines and the CAPTCHA integration are available in the repository:

git clone https://github.com/Luanace-lab/bridge-ide.git

GitHub: https://github.com/Luanace-lab/bridge-ide