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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.

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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 launch

Starts 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. 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 mode match. Close the running skill browser before switching between headless and headed mode.

Profile behavior:

  • Default mode uses: ~/.cache/agent-web/browser/fresh-profile
  • --profile mode uses: ~/.cache/agent-web/browser/profile-copy
  • The skill does not attach to your live Chrome profile directly
  • If :9222 is 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 --headless

Optional debug endpoint override:

BROWSER_DEBUG_PORT=9333 ./scripts/start.js --headless

Navigate

./scripts/nav.js https://example.com
./scripts/nav.js https://example.com --new

Navigate 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 --reset

Set 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-page

Takes 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.js

Quick 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-page

Background Logging (Console + Errors + Network)

Automatically started by start.js and writes JSONL logs to:

~/.cache/agent-web/logs/YYYY-MM-DD/<targetId>.jsonl

Manually start:

./scripts/watch.js

Tail latest log:

./scripts/logs-tail.js           # dump current log and exit
./scripts/logs-tail.js --follow  # keep following

Summarize network responses:

./scripts/net-summary.js
Repository
mitsuhiko/agent-stuff
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