Playwright Stealth Verify

Playwright, Puppeteer, Selenium, or raw CDP sessions can each leave fingerprint tells that a site might notice, and this skill gives you a way to measure them instead of guessing. It wraps the liarjs library around a Page you already have, so the check runs against your real launch flags, plugins, and proxy. Checks cover `navigator.webdriver`, a leftover HeadlessChrome token in the UA, patched APIs that no longer report `[native code]`, and whether WebGL and WebGPU agree on the GPU. The worker-versus-main-thread check is the one people tend to miss, since partial overrides often patch the main thread and leave workers telling a different story. It's a good fit for a test assertion on a score threshold, and you can run `--offline` if the harness can't reach outside the test network.

skills.sh installs: 119K
GitHub stars: 5
last updated: Oct 26, 2026

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Install

$ npx -y skills add liarjsdev/liarjs-skills --skill playwright-stealth-verify --agent claude-code

Installs into .claude/skills of the current project.

Files

Verify an automation harness against itself

A test browser that quietly looks wrong is a test suite that quietly gets challenged. liarjs answers one question about a harness: does its JavaScript story agree with itself and with what the network layer saw? It measures; it does not modify the browser and ships no evasions or profiles.

Node 22 or newer. Zero runtime dependencies, so it adds nothing to an existing Playwright or Puppeteer install.

Against a Page you already have

checkPage works with any object exposing evaluate(expression: string). Playwright and Puppeteer Page objects both qualify, so the harness under test is the harness being measured, with its real launch flags, real plugins and real proxy in place.

import { checkPage } from 'liarjs';

const result = await checkPage(page);

expect(result.score).toBeGreaterThanOrEqual(85);

// Or assert on specific ids rather than a single number:
const critical = result.checks.filter((c) => c.status === 'bad');
expect(critical, JSON.stringify(critical, null, 2)).toHaveLength(0);

SKILL.md on GitHub