PawBrowse

Let your AI coding agent drive the real Chrome you already use — logged in, no keys, no second AI.

_{A real run on live Google Flights at 1× speed — every frame is the original screencast, and the result is checked from the page itself. MP4}

PawBrowse gives your coding agent hands and eyes in the browser you're already signed into. It's a small Chrome extension + a one-file MCP server (zero dependencies). Your agent — Claude Code, Cursor, VS Code, Claude Desktop, anything that speaks MCP — can see and click your actual tabs: your profile, your logins, your open pages. No remote-debug port, no relaunch, no second AI model, no API key. The agent you already trust is the only brain in the loop.

The same power as the first-party Claude-in-Chrome extension — but yours, open source, auditable, and about 2× fewer round-trips because it reads pages as a table instead of screenshotting them.

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Try it — about 30 seconds

Two clicks and one line. 👇

1. Add the extension to Chrome

One click on the Chrome Web Store — that's the "hands and eyes" in your browser.

2. Connect your agent

• Claude Desktop — click the badge, then double-click the downloaded pawbrowse.mcpb (or drag it into Settings → Extensions) and hit Install. No command, no config.

• Cursor / VS Code — click the badge and approve.

• Claude Code — paste one line:

  claude mcp add --scope user pawbrowse -- npx -y pawbrowse@latest
  

3. Restart your client and just ask

"use pawbrowse: what's my browser status?"

You should see extension_connected: true, and the extension badge turns green ●. 🎉 You're driving.

_{Needs Node.js ≥ 18. Nothing to clone or build — the button/line just runs npx -y pawbrowse@latest. Prefer to build from source or contribute? See CONTRIBUTING.md.}

What can I ask it?

You never call the tools yourself — you talk to your agent in plain English, and it drives whatever tab you point it at:

• "Open news.ycombinator.com and give me the top 5 story titles."
• "On this tab, search for 'open source license' and open the first result."
• "Fill the signup form with my name and email — but don't submit."
• "Go to my GitHub notifications and tell me what's new."

It works on the tab you already have open and are logged into — no separate window, no re-login. Name a tab and it uses that one; otherwise it uses the active tab.

How it works — it reads pages as a table, not screenshots

Every time it looks, PawBrowse hands your agent a compact, numbered list of the clickable things in view — with real accessible names, current values, and state flags — instead of a screenshot:

Web browser - Wikipedia  —  https://en.wikipedia.org/wiki/Web_browser
scroll 0/6361  ·  83 controls
e2   fill    "Search Wikipedia"
e6   click   "Log in"
e10  click   "2 History"
e13  click ▾ "Toggle Browser market subsection"
e9   click✓  "Remember me"
e3   select  "Country"  opts{US | UK | ...}

_{Flags after the kind: ✓/· checked/unchecked · ▾/▸ expanded/collapsed · ◉ selected.}

Each ref (e10) is a stable handle to a real element, and every action returns the fresh table. So your agent acts in one round-trip — no "screenshot, think, screenshot again." That's the whole speed story (benchmark below), and it's cheaper in tokens too.

Under the hood it's boringly simple: a Chrome MV3 extension drives your tabs through Chrome's built-in chrome.debugger (CDP — no debug port, no relaunch), and a one-file MCP server bridges it to your agent over localhost. Open as many editors/agents as you like — the first one starts a shared broker, and each session gets its own 🐾 tab group so nothing fights over the port or a tab.

Claude Code ──stdio (MCP)──▶ mcp/server.mjs ─┐
Cursor      ──stdio (MCP)──▶ mcp/server.mjs ─┼─IPC─▶ broker ──ws://127.0.0.1:10577──▶ Chrome extension ──CDP──▶ your real tabs
VS Code     ──stdio (MCP)──▶ mcp/server.mjs ─┘                                              │
                                                                    each session ⇒ its own 🐾 tab group

Why it's fast

_{Same task on live Booking.com (book a 4-star Lisbon hotel — 5 actions), same agent (Claude), same real Chrome, both filmed live. The clock counts agent round-trips: one tool call = one round-trip, at the same per-call latency for both. MP4}

Why: the agent loop is round-trip-bound — each tool call is a full model inference. PawBrowse's act returns the next screen already perceived, so an action is one round-trip; a perceive-then-act driver needs two. Same task, same model → same per-call latency, so the round-trip count is the gap: 5 vs 10 → ~2×.

Honest caveats: the clock is round-trips × a fixed, equal per-call latency — it isolates the structural difference and drops network noise, it's not a stopwatch. One run each; an illustration, not a statistic. Reproduce: scripts/demo/peek-record.mjs films each tab, scripts/demo/render_race.py renders it.

How it compares

The tools

You won't call these directly — your agent does — but here's the whole surface:

Ops for browser_act: {op:"click",ref:"e12"} · {op:"click_text",text:"..."} (for custom widgets/menus not in the table) · {op:"type",ref:"e7",text:"..."} · {op:"select",ref:"e8",value:"..."} · {op:"key",key:"Enter"} · {op:"scroll",dy:600} · {op:"wait",ms:500}.

Built to be trustworthy

Two questions everyone has: does it break? and where does my data go?

It's hardened. Two multi-agent code audits plus live testing on real sites went into these:

• Hit-tested clicks — it re-resolves each element live and checks the center isn't covered before clicking, so it never hits a stale, moved, or occluded target.
• Semantic freshness guard — an element's role + name is fingerprinted, and a silently relabeled target is rejected ("observe again") instead of mis-clicked.
• Robust typing — select-all + insertText (works with React/controlled inputs); typed comboboxes wait for autocomplete to render.
• Background-tab safe — uses setTimeout-based waits (not requestAnimationFrame, which Chrome pauses in background tabs), so driving a tab you aren't looking at doesn't hang.
• No double-execution & an unwedgeable queue — overlapping calls can't race the debugger, and one hung command can't block the rest.

It stays on your machine. No model, no API key, no telemetry.

• Page content it reads goes only to the local agent you run — never to any third-party server. password, file, and hidden inputs are excluded and never exposed (other visible fields are in the table, so treat what's on screen as visible to your agent).
• The bridge binds to 127.0.0.1, rejects non-chrome-extension:// origins, and trusts only the current extension socket. It assumes other software on your machine is trusted — the same as most localhost dev tools; a per-pair token is planned hardening.
• The extension declares debugger (plus tabs, storage, alarms) and no host permissions. The only thing stored is your bridge port number.
• Fully auditable: the server is one zero-dependency file, the extension is plain JS.

Full details: SECURITY.md · PRIVACY.md. Found a vulnerability? Please don't open a public issue — see SECURITY.md.

Honest limits

• Attaching shows Chrome's "PawBrowse is debugging this browser" banner — expected.
• One debugger client per tab: a tab with DevTools open (or driven by another extension) can't be attached — switch tabs or close DevTools.
• chrome://, the Chrome Web Store, and other browser pages can't be driven (Chrome blocks automation there).
• One active client at a time — the bridge is a single localhost port, so drive from one client at a time (Claude Code or Claude Desktop). A second client says the port's in use rather than failing hard; set a different PAWBROWSE_PORT if you need both.
• Enumerates shadow DOM + same-origin iframes. Controls inside open shadow roots and same-origin iframes are in the table and clickable. Not yet: cross-origin iframes (the browser blocks them), canvas, and file uploads.

Troubleshooting

_{Requires Node ≥ 18 (≥ 22 to run the test suite). Works on Chrome, Edge, and Brave.}

Contributing

PRs welcome! See CONTRIBUTING.md for dev setup and tests (npm test), and the Code of Conduct. Questions? SUPPORT.md.

Credits

Built with Claude Code. Some page-perception and action-execution techniques are adapted from browser-use/jev-ultrafast (MIT); this credit is kept as required by that project's license.

License

MIT © PawBrowse contributors.