Web Browser
Automate and interact with web pages through Chrome or Chromium using the Chrome DevTools Protocol (CDP): navigate, click, fill forms, inspect content, take screenshots, and debug console or network activity. Use when an agent needs a real browser. Prefer headless Chrome unless visible browser interaction is required.
- Skill ID
- mitsuhiko/agent-stuff/web-browser
- Publisher
- mitsuhiko
- Repository
- agent-stuff
- Installs
- 0
- Files
- 19
- License
- Stolen from Mario
- Synced
- Sep 23, 2026
Open any RiverX project, open the Skills panel in the chat, and search for this identifier. The files are fetched from the source repository at install time.
mitsuhiko/agent-stuff/web-browserInstalls these files- SKILL.md
- scripts/browser-processes.js
- scripts/browser-processes.test.js
- scripts/cdp.js
- scripts/devices.js
- scripts/dismiss-cookies.js
- scripts/emulate.js
- scripts/emulation-state.js
- scripts/eval.js
- scripts/logs-tail.js
- scripts/nav.js
- scripts/net-summary.js
- scripts/package-lock.json
- scripts/package.json
- scripts/pick.js
- scripts/screenshot.js
- scripts/start.js
- scripts/stop.js
- scripts/watch.js
What this skill tells the agent
Web Browser Skill
Minimal CDP tools for collaborative site exploration.
Start Chrome (Prefer Headless)
./scripts/start.js --headless # Recommended: isolated reusable profile
./scripts/start.js --headless --profile # Headless with a copy of your profile
./scripts/start.js # Visible browser window when needed
./scripts/start.js --headless --reset-profile # Clear cached profile before launchStarts Chrome with remote debugging (default port :9222). Agents should use `--headless` by default because it is less disruptive and supports navigation, evaluation, screenshots, emulation, and logging. User extensions are disabled for headless launches; a copied profile still provides its cookies and other browser state, but extension-based features are unavailable. Headed launches continue to load extensions normally. Use headed mode only when a person needs to see or interact with the browser, such as for pick.js, manual authentication, or debugging a headless-specific difference.
The start script only reuses a running browser when its profile and launch settings match. Stop the running skill browser before switching between headless and headed mode. Changing the debugging port does not isolate the profile: startup refuses to modify a profile already used on another port and preserves Chrome's profile locks.
Profile behavior:
- Default mode uses:
~/.cache/agent-web/browser/fresh-profile --profilemode uses:~/.cache/agent-web/browser/profile-copy- The skill does not attach to your live Chrome profile directly
- If
:9222is already used by an unknown instance, start will fail instead of reusing it
If Chrome is installed in a non-standard location, set:
BROWSER_BIN=/path/to/chrome ./scripts/start.js --headlessOptional debug endpoint override:
BROWSER_DEBUG_PORT=9333 ./scripts/start.js --headlessStop Chrome
./scripts/stop.js # Stop skill Chrome on :9222
BROWSER_DEBUG_PORT=9333 ./scripts/stop.js # Stop skill Chrome on :9333
./scripts/stop.js --all # Stop all skill Chrome instancesWorks for headless and headed browsers. Only processes using the skill's cached profiles are stopped, not your regular Chrome. Shutdown preserves cookies and other cached state; it never force-kills Chrome. Stop before using --reset-profile.
To switch to a visible browser:
./scripts/stop.js
./scripts/start.jsNavigate
./scripts/nav.js https://example.com
./scripts/nav.js https://example.com --newNavigate current tab or open new tab.
Device Emulation (Mobile)
./scripts/emulate.js --list
./scripts/emulate.js iphone-14
./scripts/emulate.js pixel-7 --landscape
./scripts/emulate.js --resetSet an active device emulation preference (viewport, DPR, touch, UA) for browser skill commands. Use --reset to clear.
Commands like nav.js, eval.js, pick.js, dismiss-cookies.js, and screenshot.js automatically apply the active preference.
Evaluate JavaScript
./scripts/eval.js 'document.title'
./scripts/eval.js 'document.querySelectorAll("a").length'
./scripts/eval.js 'document.querySelector("button")?.click(); "clicked"'
./scripts/eval.js 'await Promise.resolve(document.title)'
./scripts/eval.js 'JSON.stringify(Array.from(document.querySelectorAll("a")).map(a => ({ text: a.textContent.trim(), href: a.href })).filter(link => !link.href.startsWith("https://")))'Execute JavaScript in the active tab. Input can be an expression or statement list; the console-style completion value is printed and promises/top-level await are awaited. Be careful with string escaping, best to use single quotes.
Screenshot
./scripts/screenshot.js
./scripts/screenshot.js --full-page
./scripts/screenshot.js --device iphone-14
./scripts/screenshot.js --device pixel-7 --full-pageTakes a screenshot and returns a temp file path.
- Default: current viewport
--full-page: captures full document height--device <preset>: temporary mobile emulation for that screenshot only
Pick Elements
./scripts/pick.js "Click the submit button"Interactive element picker. Click to select, Cmd/Ctrl+Click for multi-select, Enter to finish. This requires headed Chrome; launch start.js without --headless.
Dismiss Cookie Dialogs
./scripts/dismiss-cookies.js # Accept cookies
./scripts/dismiss-cookies.js --reject # Reject cookies (where possible)Automatically dismisses EU cookie consent dialogs.
Run after navigating to a page:
./scripts/nav.js https://example.com && ./scripts/dismiss-cookies.jsQuick Mobile Debug Flow
./scripts/start.js --headless
./scripts/nav.js https://example.com
./scripts/emulate.js iphone-14
./scripts/nav.js https://example.com # reload with mobile UA
./scripts/dismiss-cookies.js
./scripts/screenshot.js --full-pageBackground Logging (Console + Errors + Network)
Automatically started by start.js and writes JSONL logs to:
~/.cache/agent-web/logs/YYYY-MM-DD/<targetId>.jsonlManually start:
./scripts/watch.jsTail latest log:
./scripts/logs-tail.js # dump current log and exit
./scripts/logs-tail.js --follow # keep followingSummarize network responses:
./scripts/net-summary.jsMore from mitsuhiko
Use this skill in a project
Open any RiverX project, search the Skills panel for mitsuhiko/agent-stuff/web-browser, and install it in one click.
