mini-browser (mb) — Browser CLI for Agents mb is a browser CLI where each command is a small Unix tool. It talks to Chrome over CDP (port 9222) via puppeteer-core. Setup (only if not already available) Setup is only needed when mb is not installed or Chrome is not reachable. Run these checks first — if both pass, skip straight to the Command Reference. Check if ready

1. Is mb installed?

which mb && echo "mb: ok" || echo "mb: MISSING"

2. Is Chrome listening on CDP?

curl -sf http://127.0.0.1:9222/json/version

/dev/null && echo "chrome: ok" || echo "chrome: NOT RUNNING" If both print "ok", everything is ready — go use mb commands directly. Install (only if mb is missing) npm install -g @runablehq/mini-browser Start Chrome (only if not running) mb-start-chrome This launches Chrome with --remote-debugging-port=9222 , a fresh profile, and a 1024×768 window. It no-ops if Chrome is already running. To kill and relaunch: mb-restart-chrome Verify mb go "https://example.com" && mb text Environment Variables Variable Default Description CHROME_PORT 9222 CDP port CHROME_BIN auto-detected Path to Chrome/Chromium binary CHROME_PID_FILE /.chrome-pid PID file location CHROME_USER_DATA_DIR /.chrome-profile Chrome profile directory Command Reference Navigation Command Description mb go Navigate to URL (waits for networkidle) mb url Print current URL mb back Go back mb forward Go forward Observation Command Description mb text [selector] Visible text content (default: body) mb shot [file] Screenshot to PNG (default: ./shot.png) mb snap List interactive elements with coordinates Interaction Command Description mb click Click at coordinates mb type [x y] Type text (with coords: selects first) mb fill Fill form fields by label/name/placeholder mb key Press keys (Enter, Tab, Meta+a) mb move Hover at coordinates mb drag Drag between points mb scroll [dir] [px] Scroll (default: down 500) Recording Command Description mb record start Start recording (.webm, .mp4, .gif) mb record stop Stop recording and save mb record status Check if recording is active Tabs Command Description mb tab list List open tabs mb tab new [url] Open new tab, print index mb tab close [n] Close tab (default: last) Other Command Description mb js Run JavaScript in page context mb wait Wait for ms / selector / networkidle / url:pattern mb audit Design audit (palette, typography, contrast, a11y, SEO) mb logs Stream console logs (Ctrl+C to stop) Flags Flag Default Description --timeout 30000 Command timeout --tab 0 Target tab index --json false Structured JSON output --right false Right-click --double false Double-click --fps 30 Recording frame rate --scale 1 Recording scale factor Usage Patterns Observe → Act loop The standard agent loop: snapshot the page, pick an element, act on it. mb snap