Show HN: Fortress – a stealth Chromium so your agents stop getting blocked

One browser engine to rule them all

Stealth Chromium engine

Fortress is a stealth Chromium engine that stops your scrapers and browser agents from getting blocked, with one line of code change. Bot detectors flag automation by reading the browser fingerprint; Fortress corrects that fingerprint inside Chromium's C++, so the browser presents as an ordinary Chrome install. Scrapers finish their runs, agents reach the pages they were sent to, and CreepJS, Sannysoft, BrowserScan, and live Cloudflare Turnstile all read it as human. Point your existing Playwright or Puppeteer at Fortress over CDP, and nothing else in your code changes.

_{Blink · V8 · BoringSSL patched in-tree · ANGLE / D3D11-backed WebGL · JA3/JA4-coherent TLS · monthly upstream rebase · reproducible, gauntlet-gated releases}

_{Unedited capture of the Fortress binary in a real window: it clears a live Cloudflare challenge, turns bot.sannysoft.com all green, then reads BrowserScan “Normal”. Reproduce with tools/gauntlet.py.}

pip install -U tilion-fortress       # or:  docker run --rm -p 9222:9222 tilion/fortress:latest

from tilion_fortress import Fortress
from playwright.sync_api import sync_playwright

with Fortress() as f:                                   # launches the stealth engine on a CDP endpoint
    with sync_playwright() as p:
        browser = p.chromium.connect_over_cdp(f.cdp_url)
        page = browser.new_page()
        page.goto("https://bot.sannysoft.com")
        page.screenshot(path="all-green.png")

import { Fortress } from "tilion-fortress";
import { chromium } from "playwright";

const f = await Fortress.launch();                      // stealth engine on a CDP endpoint
const browser = await chromium.connectOverCDP(f.cdpUrl);
const page = await browser.newPage();
await page.goto("https://browserscan.net");
await browser.close();
await f.close();

The 12-second tour

_{One loop, all real captures: passes CreepJS / Sannysoft / BrowserScan / rebrowser → scrapes structured data over CDP → clears Akamai on aa.com · lowes · macys · kohls (same residential IP).}

Real scraping, fully headless

_{Unedited captures of the Fortress engine driven over CDP. No stealth plugins, no JS patches: the fingerprint is corrected in the binary. Reproduce any of these with examples/scrape_demos.py.}

_{Structured extraction: records build into typed JSON as each item is read.}

Clears real Akamai — before / after

_{Same residential IP, same site (aa.com · Akamai Bot Manager). A stock/headless browser gets Access Denied (Reference #); Fortress loads the real page and Akamai issues its _abck sensor cookie — the Bot Manager accepts it as a real browser. The variable is the fingerprint, not the IP.}

_{Not a one-site fluke — same before/after on major Akamai-protected retailers, every run from the same residential IP.}

# Python / Node: prebuilt native binary auto-fetched (Linux x64 & Windows x64), SHA-256 verified
pip install tilion-fortress
npm  install tilion-fortress

# Any OS via Docker: raw CDP on :9222  (~302 MB pull / 851 MB on disk, stripped single-layer)
docker run --rm -p 9222:9222 tilion/fortress:latest

# Portable bundle (extract-and-run, like a Chromium snapshot)
tar xzf tilion-fortress-linux-x64.tar.gz            # Linux
./tilion-fortress/tilion --headless=new --remote-debugging-port=9222 --user-data-dir=/tmp/p

# Debian / Ubuntu
sudo apt install ./tilion-fortress_151.0.7908.0_amd64.deb && tilion https://example.com

Tip

The SDK ships the compiled build plus patches/, so you can rebuild the engine yourself and verify every surface correction against the source. Downloads are SHA-256-verified against the release SHA256SUMS automatically.

Fortress().start()                     # Python: stable (149) by default
Fortress(channel="latest").start()     # opt into 151

await Fortress.launch();               // Node: stable (149) by default
await Fortress.launch({ channel: "latest" });

docker run --rm -p 9222:9222 tilion/fortress:149   # or :151
# or set FORTRESS_CHANNEL=latest for either SDK

You're setting up Fortress, an open-source STEALTH Chromium engine, for browser automation.
It corrects the browser fingerprint (canvas, WebGL, audio, fonts, navigator, +30 more) in Chromium's
C++ and exposes raw CDP on http://localhost:9222, a drop-in for Playwright/Puppeteer. Do NOT add
puppeteer-stealth or any JS fingerprint patching (it self-reveals and undoes Fortress).

LAUNCH (pick one; all expose CDP on http://localhost:9222):
  Docker:  docker run -d --rm -p 9222:9222 tilion/fortress:latest
  Python:  pip install tilion-fortress    then  from tilion_fortress import Fortress; f=Fortress(); f.start()
  Node:    npm install tilion-fortress    then  import {Fortress} from "tilion-fortress"; const f=await Fortress.launch()

CONNECT (keep my existing automation code):
  Playwright(py):  browser = p.chromium.connect_over_cdp("http://localhost:9222")
  Playwright(js):  const browser = await chromium.connectOverCDP("http://localhost:9222")
  Puppeteer(js):   const browser = await puppeteer.connect({ browserURL: "http://localhost:9222" })
  browser-use / Crawl4AI / Stagehand / LangChain:  point their CDP endpoint at http://localhost:9222

PERSONA (optional; default is a coherent Windows identity). Override any surface with --uxr-* flags:
  --uxr-timezone=America/New_York --uxr-hw-concurrency=16 --uxr-languages=en-US,en

RULES:
  1) Drive over raw CDP (:9222); don't spawn chromedriver.
  2) Never pass --user-agent (use --uxr-ua-*); it desyncs UA vs UA-Client-Hints.
  3) No puppeteer-stealth / undetected-chromedriver / JS fingerprint patches.
  4) Blocked ~90% = my IP (datacenter), not the fingerprint. Use a residential/mobile proxy, then retry.

Now walk me through launching Fortress and wiring my automation to it.
Full guide: https://github.com/tiliondev/fortress/blob/main/AGENTS.md

pip install "tilion[mcp]"      # command:  tilion-mcp
#   —or, zero-install—
npx -y tilion-mcp              # auto-runs the server via uv (no global install)

{ "mcpServers": { "fortress": { "command": "tilion-mcp" } } }

claude mcp add fortress -- tilion-mcp          # or:  claude mcp add fortress -- npx -y tilion-mcp

{ "mcpServers": { "fortress": { "command": "tilion-mcp" } } }

const iframe = document.createElement('iframe'); document.body.appendChild(iframe);
const realToString = iframe.contentWindow.Function.prototype.toString;
realToString.call(navigator.__lookupGetter__('vendor')); // returns your source code. Caught.

--uxr-platform / --uxr-ua-platform / --uxr-ua-os / --uxr-ua-arch / --uxr-ua-bitness
--uxr-ua-platform-version / --uxr-ua-brand / --uxr-hw-concurrency / --uxr-device-memory
--uxr-webgl-vendor / --uxr-webgl-renderer / --uxr-webgl-fullparams
--uxr-canvas-seed / --uxr-audio-seed / --uxr-timezone / --uxr-languages
--uxr-screen-width / --uxr-screen-height / --uxr-webrtc-policy=disable_non_proxied_udp

Note

The persona rides on the command line today. The --uxr-* switches are world-readable via /proc/<pid>/cmdline, so it's one persona per launch and visible to other processes on the host. The MaskConfig runtime lands next: it delivers the persona over IPC and lifts the one-per-process limit (see what's next).

from playwright.sync_api import sync_playwright
with sync_playwright() as p:
    browser = p.chromium.connect_over_cdp("http://localhost:9222")   # Fortress under the hood

export CHROMIUM_VERSION=$(cat CHROMIUM_VERSION)
build/build.sh                         # depot_tools, sync the tag, apply patches, gn gen, ninja
build/rebase-monthly.sh 152.0.XXXX.0   # bump + 3-way apply + rebuild + gauntlet-gate

BASE=https://github.com/tiliondev/fortress/releases/download/v151.0.7908.0
curl -LO $BASE/tilion-fortress-linux-x64.tar.gz
curl -Ls $BASE/SHA256SUMS | sha256sum -c --ignore-missing     # -> OK

docker pull tilion/fortress:151.0.7908.0
docker inspect --format '{{index .RepoDigests 0}}' tilion/fortress:151.0.7908.0
# compare the printed sha256:... against the digest in the GitHub Release notes

What's next

Important

v2: MaskConfig runtime personas. An IPC-delivered, seed-driven persona graph feeding a process-global C++ MaskConfig singleton: thousands of coherence-invariant fingerprints from a single binary, per-BrowserContext identity isolation, and zero command-line footprint. The rest is on the roadmap.

Staying current

Detection keeps moving, so a stealth engine is only as good as its last rebase. Fortress tracks the latest Chromium monthly, re-runs the full gauntlet, and ships a patch whenever a detector finds a new tell, so what you run keeps matching what a real Chrome install looks like. Watch the releases to follow the v2 MaskConfig work, or star the repo if it's useful to you.

Stealth you can read, rebuild, and run yourself.