dev-browser

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 install for Chromium.
• Sandboxed scripts can't touch the host FS — pass data via stdin, read results from stdout (console.log).
• --connect attaches to a running Chrome (start it with --remote-debugging-port=9222); --headless launches 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).