| name | obscura |
| description | Use Obscura — a Rust headless browser with a Chrome DevTools Protocol server — for fast page fetches, JS execution, scraping, and CDP automation. Drop-in CDP replacement for Chrome with Puppeteer or Playwright. Trigger on requests to "open a page", "fetch a URL with JS", "scrape a site", "render this page", "automate browser via CDP", or any task where Chrome would be too heavy. Also use when the user mentions stealth fingerprinting, tracker blocking, `navigator.webdriver` masking, or evading basic bot detection. |
Obscura
Single-developer, open-source Rust headless browser. Boots instantly, ~70 MB binary, ~30 MB RAM at runtime, and serves a Chrome DevTools Protocol port that Puppeteer and Playwright connect to unchanged. You swap the binary, not the code.
Repo: https://github.com/h4ckf0r0day/obscura
Why pick Obscura over Chrome
| Obscura | Chrome |
|---|
| Binary | ~70 MB | ~300 MB |
| RAM | ~30 MB | ~200 MB |
| Cold start | instant | ~2 s |
| Page load (upstream claim) | ~85 ms | varies |
Field measurement on Cloudflare-protected nairaland.com (warm fetch): Obscura ~4.1–4.9 s, returns real HTML body. Real Chrome over CDP: ~5.1 s warm / 9.3 s cold. curl: 0.5–0.9 s but only the CF challenge interstitial.
Obscura is roughly as fast as warm Chrome, ~2× faster cold, parallelizes far better because it doesn't carry Chrome's per-process overhead, and clears Cloudflare's basic JS challenge without the stealth feature.
Build
git clone https://github.com/h4ckf0r0day/obscura.git
cd obscura
CARGO_TARGET_DIR=/tmp/obscura-target cargo build -p obscura-cli --bin obscura
Resulting binary: /tmp/obscura-target/debug/obscura
The default build has no stealth and needs no extra tools. Stealth is opt-in (see below) and pulls wreq / BoringSSL, so it needs cmake locally.
Stealth build
CARGO_TARGET_DIR=/tmp/obscura-target cargo build -p obscura-cli --bin obscura --features stealth
What stealth gives you:
- Consistent browser fingerprint so cross-layer checks pass: the TLS ClientHello, User-Agent,
navigator surfaces, and WebGL renderer all agree on one Chrome identity rather than contradicting each other
- 3,520 tracker domains blocked (built-in blocklist)
navigator.webdriver masked- Native functions patched so common automation detectors can't unmask them via
Function.prototype.toString inspection
- TLS / HTTP-2 fingerprint matching real Chromium (defeats most JA3/JA4 + ALPN-ordering bot management)
Enable it at runtime with the global --stealth flag (works on fetch, serve, scrape, and mcp, before or after the subcommand). The flag needs a stealth-feature build for the TLS layer; without it --stealth still does tracker blocking.
/tmp/obscura-target/debug/obscura fetch https://example.com/ --stealth --dump text
Use stealth against: Cloudflare Turnstile non-interactive, Akamai BMP, PerimeterX, DataDome.
Stealth still won't clear: hard interactive CAPTCHAs (Turnstile interactive, hCaptcha challenge), and fingerprinters using WebGPU/WebAssembly quirks not yet patched.
CLI fetch
/tmp/obscura-target/debug/obscura fetch https://example.com/ --dump text --quiet
Useful flags:
--dump text: visible text only--dump html: full rendered DOM--dump assets: every external resource plus fetch()/XHR URLs, one JSON object per line--dump cookies: all cookies as JSON, including HttpOnly--quiet: suppress progress logs--timeout <ms>: per-page timeout
CDP server (Puppeteer / Playwright)
/tmp/obscura-target/debug/obscura serve --port 9222
Playwright:
import { chromium } from "playwright-core";
const browser = await chromium.connectOverCDP("ws://127.0.0.1:9222");
const page = await browser.newContext().then((ctx) => ctx.newPage());
await page.goto("https://example.com/");
console.log(await page.title());
await browser.close();
Puppeteer:
import puppeteer from "puppeteer-core";
const browser = await puppeteer.connect({
browserWSEndpoint: "ws://127.0.0.1:9222/devtools/browser",
});
const page = await browser.newPage();
await page.goto("https://example.com/");
console.log(await page.title());
await browser.disconnect();
Request interception
Over CDP, page.setRequestInterception(true) (Puppeteer) or page.route (Playwright) block, modify, or mock requests as usual. Embedding the engine with the obscura Rust crate gives the same thing as a native Page API: on_request / on_response callbacks (capture SPA API payloads without reverse-engineering the bundle), an enable_interception() channel to block, mock, or rewrite, and add_preload_script to run code before the page's own scripts.
Scaling profile
- ✅ High concurrency, low resource: static + lightly-dynamic pages — hundreds of parallel fetches per box.
- ⚠️ Medium: JS-rendered SPAs, light bot protection — works but slower than raw HTTP, watch timeouts.
- ❌ Low / unreliable: aggressive bot defense (Turnstile interactive, Akamai BMP), real auth-walled apps, anything needing pixel-perfect rendering parity with Chrome.
Known limits
- Not full Chrome — some browser APIs and CDP methods are incomplete relative to upstream Chromium.
- Screenshot capture is not implemented (no layout/rendering engine).
- Authenticated pages need cookie or session injection via CDP; Obscura won't run interactive logins.
- Hard CAPTCHAs (Turnstile interactive, hCaptcha) require a human or a third-party solver.
Safety
Treat Obscura like any external Rust crate: cargo build runs dependency build scripts (V8, TLS). Build into a disposable target dir (CARGO_TARGET_DIR=/tmp/obscura-target) when evaluating new branches.
