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h4ckf0r0day/obscura

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The headless browser for AI agents and web scraping

23,4341,734Rustantidetectantidetect-browserbrowserbrowser-automationcdpheadlessplaywrightpuppeteerrustUpdated 2d ago
README

Obscura is a headless browser engine written in Rust, built for web scraping and AI agent automation. It runs real JavaScript via V8, supports the Chrome DevTools Protocol, and acts as a drop-in replacement for headless Chrome with Puppeteer and Playwright.

Why Obscura over headless Chrome?

| Metric | Obscura | Headless Chrome | |--------------|--------------|------------------| | Memory | 30 MB | 200+ MB | | Binary size | 70 MB | 300+ MB | | Anti-detect | Built-in | None | | Page load | 85 ms | ~500 ms | | Startup | Instant | ~2s | | Puppeteer | Yes | Yes | | Playwright | Yes | Yes |

Obscura Cloud

We are working on Obscura Cloud the hosted version, with managed infrastructure, residential proxies, and dedicated support. For people who want the engine without operating it themselves.

The open-source engine stays Apache-2.0, fully featured. No feature gating, ever.

Get on the waitlist → 📅 Book a demo →

Sponsors

Obscura is supported by organizations helping us build independent open-source browser infrastructure.

Want to sponsor? Email hello@obscura.sh.

Install

Download

Grab the latest binary from Releases:

# Linux x86_64
curl -LO https://github.com/h4ckf0r0day/obscura/releases/latest/download/obscura-x86_64-linux.tar.gz
tar xzf obscura-x86_64-linux.tar.gz
./obscura fetch https://example.com --eval "document.title"

# Linux ARM64 (aarch64)
curl -LO https://github.com/h4ckf0r0day/obscura/releases/latest/download/obscura-aarch64-linux.tar.gz
tar xzf obscura-aarch64-linux.tar.gz

# Arch Linux (AUR)
yay -S obscura-browser

# NixOS
nix-env -iA nixpkgs.obscura

# macOS Apple Silicon
curl -LO https://github.com/h4ckf0r0day/obscura/releases/latest/download/obscura-aarch64-macos.tar.gz
tar xzf obscura-aarch64-macos.tar.gz

# macOS Intel
curl -LO https://github.com/h4ckf0r0day/obscura/releases/latest/download/obscura-x86_64-macos.tar.gz
tar xzf obscura-x86_64-macos.tar.gz

# Windows
Download the `.zip` from the releases page and extract it manually.

No Chrome, no Node.js, no dependencies. Release archives include both obscura and obscura-worker; keep them in the same directory for the parallel scrape command.

| Archive suffix | Rendering | Stealth transport | |----------------|-----------|-------------------| | none | Yes | No | | -stealth | Yes | Yes | | -no-render | No | No | | -no-render-stealth | No | Yes |

Linux release builds target Ubuntu 22.04 so the downloaded binary remains usable on common LTS servers with glibc 2.35+.

Docker

docker run -d --name obscura -p 127.0.0.1:9222:9222 h4ckf0r0day/obscura

Image on Docker Hub. Multi-stage build on distroless/cc, no shell, no package manager, ~57 MB compressed.

Build from source

git clone https://github.com/h4ckf0r0day/obscura.git
cd obscura

# Rendering
cargo build --release -p obscura-cli --bins --features render

# Rendering and stealth
cargo build --release -p obscura-cli --bins --features render,stealth

# No rendering
cargo build --release -p obscura-cli --bins --no-default-features

# No rendering, with stealth
cargo build --release -p obscura-cli --bins --no-default-features --features stealth

Requires Rust 1.75+ (rustup.rs). First build takes ~5 min (V8 compiles from source, cached after). The stealth build also compiles BoringSSL and generates bindings, so it needs CMake, Clang, and the libclang/LLVM development libraries. On Ubuntu/Debian:

sudo apt-get install build-essential cmake clang libclang-dev llvm-dev

The rendering build uses rustls. The rendering-and-stealth build uses wreq/BoringSSL and therefore needs the additional build tools above.

Quick Start

Fetch a page

# Get the page title
obscura fetch https://example.com --eval "document.title"

# Extract all links
obscura fetch https://example.com --dump links

# Render JavaScript and dump HTML
obscura fetch https://news.ycombinator.com --dump html

# Write dump or eval output to a file
obscura fetch https://example.com --dump text --output page.txt

# Stream the raw response body verbatim (binary-safe; bypasses the JS/DOM layer).
# Use this for images, JSON, JS, CSS, or any non-HTML resource.
obscura fetch https://picsum.photos/200/300 --dump original > photo.jpg

# List every sub-resource URL the page would fetch (NDJSON; one record per asset)
obscura fetch https://example.com --dump assets

# Fetch through an HTTP or SOCKS proxy
obscura --proxy socks5://127.0.0.1:1080 fetch https://example.com --dump text

# Wait for dynamic content
obscura fetch https://example.com --wait-until networkidle0

# Bound navigation time for slow or broken pages
obscura fetch https://example.com --timeout 10

# Capture the settled page as PNG
obscura fetch https://example.com --screenshot page.png

# The screenshot flag also has a short form
obscura fetch https://example.com -s page.png

### Testing against localhost / LAN dev servers

Obscura blocks fetches to private/internal IPs by default (SSRF protection).
To point it at a local dev server, pass `--allow-private-network` (or set
`OBSCURA_ALLOW_PRIVATE_NETWORK=1`):

```bash
obscura fetch http://127.0.0.1:3000 --allow-private-network --dump text

# Works on any subcommand, e.g. the CDP server for local Puppeteer/Playwright:
obscura serve --port 9222 --allow-private-network

See docs/Environment-variables.md for the full allow/deny rules (DNS-resolution-time checks included).


## Rendering

Official release archives and the Docker image include the rendering engine.
It provides CSS layout and paint, viewport and full-page screenshots,
scroll-aware fixed and sticky geometry, activity-driven CDP screencasting, and
raster PDF export without starting Chromium.

```javascript
await page.setViewport({ width: 1440, height: 1000 });
await page.goto('https://example.com', { waitUntil: 'load' });
await page.screenshot({ path: 'page.png', fullPage: true });
await page.pdf({ path: 'page.pdf', format: 'A4', printBackground: true });

The current implementation covers block, inline, flex, grid, table, float, positioning, overflow, transform, text, image, SVG, canvas, background, border, and animation paths. It remains an evolving independent engine: long-tail CSS, some Web APIs, media playback, compositor effects, and platform font rasterization may differ from Chromium. The existing Puppeteer, Playwright, and MCP guides cover their capture APIs and limits.

Start the CDP server

obscura serve --port 9222

# With stealth mode (anti-detection + tracker blocking)
obscura serve --port 9222 --stealth

Scrape in parallel

obscura scrape url1 url2 url3 ... \
  --concurrency 25 \
  --eval "document.querySelector('h1').textContent" \
  --format json

# Suppress scrape progress on stderr for script-friendly output
obscura scrape https://example.com --quiet --format json

# Scrape workers inherit the global proxy
obscura --proxy http://127.0.0.1:8080 scrape https://example.com https://news.ycombinator.com

Puppeteer / Playwright

Puppeteer

npm install puppeteer-core
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://news.ycombinator.com');

const stories = await page.evaluate(() =>
  Array.from(document.querySelectorAll('.titleline > a'))
    .map(a => ({ title: a.textContent, url: a.href }))
);
console.log(stories);

await browser.disconnect();

Playwright

npm install playwright-core
import { chromium } from 'playwright-core';

const browser = await chromium.connectOverCDP({
  endpointURL: 'ws://127.0.0.1:9222',
});

const page = await browser.newContext().then(ctx => ctx.newPage());
await page.goto('https://en.wikipedia.org/wiki/Web_scraping');
console.log(await page.title());

await browser.close();

Form submission & login

await page.goto('https://quotes.toscrape.com/login');
await page.evaluate(() => {
  document.querySelector('#username').value = 'admin';
  document.querySelector('#password').value = 'admin';
  document.querySelector('form').submit();
});
// Obscura handles the POST, follows the 302 redirect, maintains cookies

Benchmarks

Page load:

| Page | Obscura | Chrome | |------|---------|--------| | Static HTML | 51 ms | ~500 ms | | JS + XHR + fetch | 84 ms | ~800 ms | | Dynamic scripts | 78 ms | ~700 ms |

The full benchmark suite (WPT conformance, obstacle course, real-world corpus, and vs-Chrome speed) lives in a separate repo: https://github.com/h4ckf0r0day/obscura-benchmark

Stealth Mode

Build with --features render,stealth, then enable stealth at runtime with the global --stealth flag. The stealth build includes the complete rendering engine; enabling stealth does not remove screenshot, screencast, PDF, CDP, or MCP functionality.

Anti-fingerprinting

  • Per-session fingerprint randomization (GPU, screen, canvas, audio, battery)
  • Realistic navigator.userAgentData (Chrome 145, high-entropy values)
  • event.isTrusted = true for dispatched events
  • Hidden internal properties (Object.keys(window) safe)
  • Native function masking (Function.prototype.toString()[native code])
  • navigator.webdriver = undefined (matches real Chrome)

Tracker Blocking

  • 3,520 domains blocked
  • Blocks analytics, ads, telemetry, and fingerprinting scripts
  • Prevents trackers from loading entirely
  • Enabled automatically with --stealth

CDP API

Obscura implements the Chrome DevTools Protocol for Puppeteer/Playwright compatibility.

| Domain | Methods | |--------|---------| | Target | createTarget, closeTarget, attachToTarget, createBrowserContext, disposeBrowserContext | | Page | navigate, getFrameTree, lifecycleEvents, captureScreenshot, start/stopScreencast, printToPDF | | Runtime | evaluate, callFunctionOn, getProperties, addBinding | | DOM | getDocument, querySelector, querySelectorAll, getOuterHTML, resolveNode | | Network | enable, setCookies, getCookies, setExtraHTTPHeaders, setUserAgentOverride | | Fetch | enable, continueRequest, fulfillRequest, failRequest (live interception), takeResponseBodyAsStream | | IO | read, close (stream a large response body in chunks) | | Storage | getCookies, setCookies, deleteCookies | | Input | dispatchMouseEvent, dispatchKeyEvent | | LP | getMarkdown (DOM-to-Markdown conversion) |

To download a large resource without one giant Network.getResponseBody blob, call Fetch.takeResponseBodyAsStream then read it in chunks with IO.read / IO.close. Response bodies over the cache limit (OBSCURA_NETWORK_BODY_BUFFER_BYTES, default 2 MiB) are not retained, so raise that limit when you intend to stream large downloads.

CLI Reference

Tuning V8

Obscura embeds V8 directly. Use --v8-flags to pass raw flags through to V8, same syntax as Chromium's --js-flags and Node's command-line flags. Most common use is raising the heap cap to fix JavaScript heap out of memory on JS-heavy pages:

obscura --v8-flags "--max-old-space-size=4096" fetch <url>

Heavy SPAs (script execution budget)

Obscura caps the page's script-execution phase so one slow or hung page cannot stall a worker. The default budget is 30s; pages that finish sooner return immediately, so the cap only affects pages that keep running. A very heavy React/Vue/Angular SPA on a slow network can need more time to boot before it fires its data requests. Raise the budget with OBSCURA_SCRIPT_DEADLINE_MS (milliseconds), and pair it with a matching navigation timeout in your CDP client:

OBSCURA_SCRIPT_DEADLINE_MS=60000 obscura serve --port 9222

Modules that enhance an already-rendered page have a separate 3s per-module budget so one non-essential module cannot hold navigation open. Raise it for legitimate long-running modules such as a Vite HMR client:

OBSCURA_MODULE_BUDGET_MS=10000 obscura serve --port 9222

An unmounted SPA shell already gives its app modules the full OBSCURA_SCRIPT_DEADLINE_MS budget. OBSCURA_FETCH_TIMEOUT_MS controls the module's network request, not its evaluation time. See Environment variables for the complete timeout model.

obscura serve

Start a CDP WebSocket server.

| Flag | Default | Description | |------|---------|-------------| | --port | 9222 | WebSocket port | | --proxy | — | HTTP/SOCKS5 proxy URL | | --stealth | off | Enable anti-detection + tracker blocking | | --workers | 1 | Number of parallel worker processes | | --obey-robots | off | Respect robots.txt |

obscura fetch <URL>

Fetch and render a single page.

| Flag | Default | Description | |------|---------|-------------| | --dump | html | Output: html, text, links, markdown, assets (NDJSON of every sub-resource URL the page references), or original (raw response body) | | --eval | — | JavaScript expression to evaluate | | --wait-until | load | Wait: load, domcontentloaded, networkidle0 | | --timeout | 30 | Maximum navigation time in seconds | | --wait | adaptive, up to 5 | Post-load settling; an explicit value is a fixed delay in seconds | | --selector | — | Wait for CSS selector | | -s, --screenshot | — | Write a PNG screenshot (single URL; render-enabled build) | | --stealth | off | Anti-detection mode | | --output | — | Write dump or eval output to a file | | --quiet | off | Suppress banner | | --proxy | — | Inherited global HTTP/SOCKS5 proxy URL |

obscura scrape <URL...>

Scrape multiple URLs in parallel with worker processes.

| Flag | Default | Description | |------|---------|-------------| | --concurrency | 10 | Parallel workers | | --eval | — | JS expression per page | | --format | json | Output: json or text | | --quiet | off | Suppress scrape progress on stderr | | --proxy | — | Inherited global HTTP/SOCKS5 proxy URL for all workers |

MCP (Model Context Protocol)

Obscura ships an MCP server that exposes browser automation tools to AI agents (Claude Desktop, Cursor, etc.).

Start

stdio (default) — for Claude Desktop and MCP clients that launch a subprocess:

obscura mcp

HTTP — for clients that connect over the network:

obscura mcp --http --port 8080
# endpoint: http://127.0.0.1:8080/mcp

Optional flags (both transports):

| Flag | Description | |------|-------------| | --proxy <URL> | HTTP/SOCKS5 proxy | | --user-agent <UA> | Custom User-Agent string | | --stealth | Enable anti-detection mode |

Claude Desktop config

{
  "mcpServers": {
    "obscura": {
      "command": "obscura",
      "args": ["mcp"]
    }
  }
}

Tools

| Tool | Description | |------|-------------| | browser_navigate | Navigate to a URL (url, optional waitUntil: load / domcontentloaded / networkidle0) | | browser_snapshot | Return the current page URL, title, readable body text, and element references | | browser_screenshot | Return the current page as an MCP PNG image (render-enabled build) | | browser_pdf | Return the current page as an embedded PDF resource (render-enabled build) | | browser_click | Click by current snapshot reference or CSS selector | | browser_fill | Set an input value by reference or selector (triggers input + change) | | browser_type | Append text to an input | | browser_press_key | Dispatch a keyboard event (key, optional selector) | | browser_select_option | Select an <option> by value or text | | browser_evaluate | Evaluate a JavaScript expression and return the result | | browser_wait_for | Wait for a CSS selector to appear (selector, optional timeout in seconds) | | browser_network_requests | List network requests made by the current page | | browser_console_messages | Return console messages logged by the page | | browser_close | Close the page and reset browser state |

The MCP server exposes still-image and PDF output. Use CDP when you need the streaming Page.startScreencast protocol.

Integrations

  • Hermes agent plugin: run Hermes agent browser tasks on Obscura. The plugin spawns obscura serve per session (or connects to an already running server) and drives it over CDP, with optional --stealth.

License

Apache 2.0


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