rustwright 0.1.0a4

A Rust-backed, CDP-first Python automation library with a Playwright-compatible sync API

Change one import and your existing Playwright code — Python or Node — runs on an in-process Rust CDP engine. No Node driver subprocess. No Playwright fingerprint.

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Change one import

Rustwright is a drop-in for existing Playwright code — in most cases the import is the only line that changes.

Python

- from playwright.sync_api import sync_playwright
+ from rustwright.sync_api import sync_playwright

  with sync_playwright() as p:
      browser = p.chromium.launch(headless=True)
      page = browser.new_page()
      page.goto("https://example.com")
      print(page.title())
      browser.close()

Node.js

- import { chromium } from 'playwright';
+ import { chromium } from 'rustwright';

  const browser = await chromium.launch();
  const page = await browser.newPage();
  await page.goto('https://example.com');
  console.log(await page.title());
  await browser.close();

515/515 shared parity cases pass against real Playwright (growing suite; full behavioral parity in progress). rustwright.async_api mirrors Playwright's async API (concurrency notes in Limitations).

Prefer not to touch imports at all? Python offers an opt-in shim — rustwright.enable_playwright_compat() — that redirects import playwright... to Rustwright at runtime.

[!WARNING] Alpha. Chromium-only, built from source (PyPI/npm publishing is the top roadmap item). Need Firefox/WebKit or production maturity today? Use playwright-python. Full list: Limitations.

What is Rustwright?

Rustwright is a browser automation library for Python and Node.js that keeps the Playwright API you already know but drives Chromium from a native Rust engine speaking raw Chrome DevTools Protocol — no driver subprocess in the path.

playwright-python:  your code ──pipe──► Node driver (separate process) ──CDP──► Chromium
rustwright:         your code ────────────────── raw CDP ─────────────────────► Chromium

Why Rustwright?

• No Node driver subprocess. playwright-python launches and pipes to a bundled Node driver. Rustwright's engine is native — the browser-control code runs in-process.
• Raw CDP, in Rust. A from-scratch async CDP client — not a wrapper around another automation library.
• No Playwright automation fingerprint. The driver never loads, so its signatures never appear. See Signal hygiene.
• Trusted input by default. Clicks and typing go through real CDP input events (Input.dispatchMouseEvent), not synthetic element.click() DOM calls. Untrusted DOM shortcuts are opt-in only.
• Cross-origin iframes (OOPIF). Auto-attaches out-of-process iframe targets with flattened CDP sessions and routes frame_locator() across origins.
• One engine, two languages. The same Rust core backs the Python and Node bindings.

How it works

One Rust core — an async CDP client built on Tokio (WebSocket, with opt-in Unix-pipe transport) — talks to Chromium directly, and thin PyO3 (Python) and napi-rs (Node) bindings expose it in-process. The two-line diagram above is the entire architecture.

Install

No package is published yet — publishing to PyPI and npm is the top roadmap item; star or watch the repo to catch the release. Until then, Rustwright builds from source on Linux, macOS, and Windows with a Rust toolchain (1.85+).

Python (3.8+)

git clone https://github.com/Skyvern-AI/rustwright && cd rustwright
python -m venv .venv && source .venv/bin/activate
python -m pip install -U pip maturin
maturin develop --release               # compiles the Rust engine (~5 min on first build)
python -m rustwright install chromium   # fetch a Chromium build

Keep the virtual environment activated when running maturin develop — maturin can print a success message while installing nothing into a non-active environment. If import rustwright later raises ModuleNotFoundError, run source .venv/bin/activate and rerun maturin develop --release.

Node.js (experimental — contributors only for now)

cd rustwright/node
npm install
npm run build          # builds the native addon via napi-rs

The build produces a local package; consume it from another project with npm install /path/to/rustwright/node (or npm link). Only a subset of the API surface is bridged — see Limitations.

Already have a Chromium/Chrome binary? Point Rustwright at it with RUSTWRIGHT_CHROMIUM, CHROME, or CHROMIUM.

Signal hygiene

Because Rustwright never loads Playwright's Node driver, it never emits the automation signatures that ship with it:

• No Playwright driver signatures — no __playwright__binding__ / utility-world globals, no driver bootstrap. The backend reports playwright_driver: "none".
• No Runtime.enable on the default path — a normal launch + navigate never enables the CDP Runtime domain, closing the Runtime.enable console-serialization leak behind isAutomatedWithCDP. (Console/page-error/binding opt-ins still enable it lazily — detectable by design.)
• Headless identity normalized by default — launches with --disable-blink-features=AutomationControlled, rewrites HeadlessChrome/ → Chrome/ in the UA and client hints, and installs a navigator.webdriver cleanup init script.

Local fingerprint runs — default Playwright failed webdriver/headless checks that Rustwright passed; these are local diagnostics, not a guarantee:

Probe	Result
SannySoft	✅ Clean
BrowserScan	✅ Clean
DeviceAndBrowserInfo	✅ Clean (after the Runtime-domain cleanup)
CreepJS	⚠️ Detects headless

[!IMPORTANT] Rustwright is not "undetectable." It is not a CAPTCHA or Cloudflare bypass, and it is not fully CDP-invisible — it still uses CDP primitives (Target.setAutoAttach, init scripts, and lazy Runtime.enable for console event/pageerror event/binding opt-ins). The claim is narrow: no Playwright-specific automation fingerprint, plus baseline signal hygiene.

Benchmarks

Rustwright does not headline a speed number yet: launch-facing claims are held to reproducible, isolated CI evidence (Testbox + capped Docker), which is not yet published. Two diagnostic runs exist today — a local dev-host run where Rustwright won 16/17 case means, and a hosted strict run with a narrower gap:

Run	Cases	Rustwright	playwright-python	Speedup
Local dev host (warm browser, 5 iterations)	17	5,256 ms	13,418 ms	2.55×
Hosted strict run	78	—	—	~1.37×

Treat both as diagnostics, not launch claims — neither is capped-Docker/CI evidence. Methodology: BENCHMARK.md.

Rustwright vs the alternatives

	Rustwright	playwright-python	Puppeteer	Patchright
API	Playwright-shaped (Py + Node)	Official Python Playwright	JS/TS Puppeteer	Playwright drop-in fork
Engine / transport	Rust core, raw CDP	Python → Node driver	Node over CDP	Patched PW driver
In-process engine (no driver subprocess)	✅	❌ bundled Node driver	✅ Node is the runtime	❌ Playwright-style driver
Browsers	Chromium only	Chromium, Firefox, WebKit	Chrome, Firefox	Chromium-based
Default input	Trusted CDP events	Browser-level	Browser / CDP	Playwright + stealth
Cross-origin iframes	OOPIF (alpha)	Mature	Frame APIs	Inherits Playwright
Playwright fingerprint	No	Yes	n/a	Patched
Maturity	🟠 Alpha	🟢 Mature	🟢 Mature	🟡 Focused fork

Rustwright's lane: a Rust CDP engine under the Playwright API, for Chromium.

Limitations

See LIMITATIONS.md for detail.

• Alpha — API shape covered; full behavioral parity not yet proven.
• Chromium only — Firefox and WebKit error explicitly.
• Node bindings are early — a subset of the surface is bridged (launch, newPage, goto, click, fill, title, textContent, evaluate, screenshot, close); contexts, routing, tracing, and locators are Python-only for now.
• Async concurrency (Python) — the async API wraps the sync engine via threads; recommended for ≈≤25 concurrent workflows/process, not high fan-out.
• OOPIF — residual gaps in non-main-frame JSHandle follow-ups and drag/screenshot/bounding-box.
• Signal hygiene is partial — 3 of 4 public fingerprint targets clean in local runs (CreepJS still detects headless). No undetectability promise.

Roadmap

• Publish to PyPI and npm — top priority
• CI / Testbox-backed benchmark evidence
• Native async engine (remove the Python thread-pool bridge)
• Broaden the Node.js surface (contexts, routing, locators)
• Close remaining OOPIF gaps
• Split the core into maintainable modules

Recently shipped:

• OOPIF auto-attach with flattened CDP sessions
• 515/515 shared parity suite green against real Playwright
• Runtime.enable console-serialization leak closed on the default path

Firefox and WebKit are not planned — Rustwright is deliberately Chromium-only.

Contributing

Rustwright is Rust + Python + Node. cargo builds the engine; maturin develop --release installs the Python package; cd node && npm run build builds the Node addon; the Python suite exercises the engine against real Chromium. Full Docker gate: 1,046 tests pass (6 skipped), plus 515/515 shared parity cases run against real Playwright; CI (test.yml) runs a fast representative subset on every PR.

See CONTRIBUTING.md for build details and the code-layout reality.

Project status

Rustwright is an early alpha from Skyvern, developed in the open. If the architecture resonates, give it a ⭐.

Questions, ideas, or want to help? Join the Skyvern community on Discord.

License

MIT © 2026 Ikonomos Inc (dba Skyvern)

_{Built with 🦀🐉 and a lot of CDP frames · Skyvern-AI/rustwright}