CloakBrowser Fallback

Leading words: stealth browser, fallback, humanize, bot detection, Turnstile, headless failover, real Chromium binary.

Stealth Chromium for navigating sites that block ordinary automation. Drop-in Playwright API, but the browser is a custom-compiled Chromium binary, so detectors score it as a real human browser.

Already installed on this machine. Both languages share the same stealth binary at ~/.cloakbrowser/:

• Python (global): pip package cloakbrowser.
• JS (self-contained in this skill's scripts/): npm cloakbrowser + playwright-core.

Prefer Python by default. Use JS when the target codebase/repo is JS/TS or the user asks for it.

When to reach for this

Use as a fallback only — try the built-in browser tool or Chrome DevTools MCP first. Escalate to CloakBrowser when any of the triggers in the frontmatter when_to_use fire (403/429, Cloudflare/Turnstile/reCAPTCHA walls, empty/blocked response, explicit user ask).

Headless failover pattern: start headless. If a Turnstile managed challenge appears, re-run with --headed — it clears with one click after the page settles. If an image CAPTCHA appears, stop and report to the user — CloakBrowser does not solve image CAPTCHAs.

Quick start (one-shot fetch)

Run the helper — it prints final URL, title, and page text, and saves a screenshot.

Python:

python scripts/cloak_fetch.py "https://protected-site.com"

JS (run from this skill's scripts/ dir so node_modules resolves):

node scripts/cloak_fetch.mjs "https://protected-site.com"

Both accept the same flags:

• --headed — show the window. Needed for Turnstile managed challenges (resolves with a single click).
• --screenshot path.png — where to save the screenshot (default: cloak_shot.png).
• --html path.html — also dump raw HTML.
• --wait 5000 — extra ms to wait after load for JS challenges to clear.

Inline usage (when you need custom interaction)

Python (sync API):

from cloakbrowser import launch

browser = launch(headless=True, humanize=True)  # humanize=True → human-like mouse/keyboard
page = browser.new_page()
page.goto("https://protected-site.com", wait_until="domcontentloaded")
page.wait_for_timeout(4000)                       # let JS challenges clear
print(page.title())
page.screenshot(path="cloak_shot.png", full_page=True)
html = page.content()
browser.close()

JS (async API):

import { launch } from "cloakbrowser";

const browser = await launch({ headless: true, humanize: true });
const page = await browser.newPage();
await page.goto("https://protected-site.com", { waitUntil: "domcontentloaded" });
await page.waitForTimeout(4000);
console.log(await page.title());
await page.screenshot({ path: "cloak_shot.png", fullPage: true });
const html = await page.content();
await browser.close();

Everything else is standard Playwright (click, fill, locator, etc.) — same API you already know.

Decision notes

• Turnstile non-interactive → works headless, auto-resolves.
• Turnstile managed → use --headed; it clears with one click after the page settles (the headless-failover pattern from above).
• CloakBrowser does not solve image CAPTCHAs and has no built-in proxy rotation. If a site demands an image CAPTCHA, report that to the user rather than looping.
• Don't use this to defeat paywalls/auth or violate a site's terms — it's for reaching content blocked by overzealous bot detection during legitimate work.

Verifying / maintaining the binary

python -m cloakbrowser info     # version, path, platform
python -m cloakbrowser install  # download binary if missing (~535 MB, one-time)
python -m cloakbrowser update   # pull a newer stealth Chromium

If a run fails with "binary not found", run python -m cloakbrowser install first.