l3ad3r1 Dev Browser
Control a real browser with sandboxed JavaScript scripts, powered by the
open-source dev-browser CLI
(a thin, safe wrapper over the full Playwright API).
When to Use
- Open a URL and read / screenshot it.
- Scrape or extract data from a page (especially JS-rendered sites).
- Fill in and submit a web form, or click through a flow.
- End-to-end test a web app in a real browser.
- Anything a plain HTTP fetch can't do (logins, dynamic SPA content).
Prerequisites
npm install -g dev-browser
dev-browser install # installs Playwright + Chromium
Requires Node.js. On Windows the installer pulls the native
dev-browser-windows-x64.exe automatically.
Usage
Pipe a JavaScript snippet into dev-browser. Scripts run in a QuickJS WASM
sandbox (no host filesystem access); a browser object is provided, and pages
persist across invocations.
dev-browser --headless <<'EOF'
const page = await browser.getPage("main");
await page.goto("https://example.com", { waitUntil: "domcontentloaded" });
console.log(await page.title());
EOF
Windows PowerShell uses a here-string:
@"
const page = await browser.getPage("main");
await page.goto("https://example.com", { waitUntil: "domcontentloaded" });
console.log(await page.title());
"@ | dev-browser --headless
Run dev-browser --help for the full LLM usage guide and API reference
(goto, click, fill, locators, evaluate, screenshot, …).
Notes & Limits
- Needs Node.js and a one-time
dev-browser installfor Chromium. - Sandboxed scripts can't touch the host FS — pass data via stdin, read results
from stdout (
console.log). --connectattaches to a running Chrome (start it with--remote-debugging-port=9222);--headlesslaunches fresh Chromium.
Credits
Wraps the open-source dev-browser CLI by Sawyer Hood (MIT), brought to you by Do Browser. All credit for the engine belongs to its authors; this skill only adds usage guidance. Packaged by Rinu (l3ad3r1) with Claude (Anthropic).