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Chrome extension (browser relay)

The Clawdbot Chrome extension lets the agent control your existing Chrome tabs (your normal Chrome window) instead of launching a separate clawd-managed Chrome profile. Attach/detach happens via a single Chrome toolbar button.

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What it is (concept)

There are three parts:
  • Browser control server (HTTP): the API the agent/tool calls (browser.controlUrl)
  • Local relay server (loopback CDP): bridges between the control server and the extension (http://127.0.0.1:18792 by default)
  • Chrome MV3 extension: attaches to the active tab using chrome.debugger and pipes CDP messages to the relay
Clawdbot then controls the attached tab through the normal browser tool surface (selecting the right profile).

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Install / load (unpacked)

  1. Install the extension to a stable local path:
clawdbot browser extension install
  1. Print the installed extension directory path:
clawdbot browser extension path
  1. Chrome → chrome://extensions
  • Enable “Developer mode”
  • “Load unpacked” → select the directory printed above
  1. Pin the extension.

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Updates (no build step)

The extension ships inside the Clawdbot release (npm package) as static files. There is no separate “build” step. After upgrading Clawdbot:
  • Re-run clawdbot browser extension install to refresh the installed files under your Clawdbot state directory.
  • Chrome → chrome://extensions → click “Reload” on the extension.

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Use it (no extra config)

Clawdbot ships with a built-in browser profile named chrome that targets the extension relay on the default port. Use it:
  • CLI: clawdbot browser --browser-profile chrome tabs
  • Agent tool: browser with profile="chrome"
If you want a different name or a different relay port, create your own profile: 
clawdbot browser create-profile \
  --name my-chrome \
  --driver extension \
  --cdp-url http://127.0.0.1:18792 \
  --color "#00AA00"

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Attach / detach (toolbar button)

  • Open the tab you want Clawdbot to control.
  • Click the extension icon.
    • Badge shows ON when attached.
  • Click again to detach.

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Which tab does it control?

  • It does not automatically control “whatever tab you’re looking at”.
  • It controls only the tab(s) you explicitly attached by clicking the toolbar button.
  • To switch: open the other tab and click the extension icon there.

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Badge + common errors

  • ON: attached; Clawdbot can drive that tab.
  • …: connecting to the local relay.
  • !: relay not reachable (most common: browser relay server isn’t running on this machine).
If you see !:
  • Make sure the Gateway is running locally (default setup), or run clawdbot browser serve on this machine (remote gateway setup).
  • Open the extension Options page; it shows whether the relay is reachable.

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Do I need clawdbot browser serve?

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Local Gateway (same machine as Chrome) — usually no

If the Gateway is running on the same machine as Chrome and your browser.controlUrl is loopback (default), you typically do not need clawdbot browser serve. The Gateway’s built-in browser control server will start on http://127.0.0.1:18791/ and Clawdbot will auto-start the local relay server on http://127.0.0.1:18792/.

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Remote Gateway (Gateway runs elsewhere) — yes

If your Gateway runs on another machine, run clawdbot browser serve on the machine that runs Chrome (and publish it via Tailscale Serve / TLS). See the section below.

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Sandboxing (tool containers)

If your agent session is sandboxed (agents.defaults.sandbox.mode != "off"), the browser tool can be restricted:
  • By default, sandboxed sessions often target the sandbox browser (target="sandbox"), not your host Chrome.
  • Chrome extension relay takeover requires controlling the host browser control server.
Options:
  • Easiest: use the extension from a non-sandboxed session/agent.
  • Or allow host browser control for sandboxed sessions:
{
  agents: {
    defaults: {
      sandbox: {
        browser: {
          allowHostControl: true
        }
      }
    }
  }
}
Then ensure the tool isn’t denied by tool policy, and (if needed) call browser with target="host". Debugging: clawdbot sandbox explain

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Remote Gateway (recommended: Tailscale Serve)

Goal: Gateway runs on one machine, but Chrome runs somewhere else. On the browser machine: 
clawdbot browser serve --bind 127.0.0.1 --port 18791 --token <token>
tailscale serve https / http://127.0.0.1:18791
On the Gateway machine:
  • Set browser.controlUrl to the HTTPS Serve URL (MagicDNS/ts.net).
  • Provide the token (prefer env):
export CLAWDBOT_BROWSER_CONTROL_TOKEN="<token>"
Then the agent can drive the browser by calling the remote browser.controlUrl API, while the extension + relay stay local on the browser machine.

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How “extension path” works

clawdbot browser extension path prints the installed on-disk directory containing the extension files. The CLI intentionally does not print a node_modules path. Always run clawdbot browser extension install first to copy the extension to a stable location under your Clawdbot state directory. If you move or delete that install directory, Chrome will mark the extension as broken until you reload it from a valid path.

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Security implications (read this)

This is powerful and risky. Treat it like giving the model “hands on your browser”.
  • The extension uses Chrome’s debugger API (chrome.debugger). When attached, the model can:
    • click/type/navigate in that tab
    • read page content
    • access whatever the tab’s logged-in session can access
  • This is not isolated like the dedicated clawd-managed profile.
    • If you attach to your daily-driver profile/tab, you’re granting access to that account state.
Recommendations:
  • Prefer a dedicated Chrome profile (separate from your personal browsing) for extension relay usage.
  • Keep the browser control server tailnet-only (Tailscale) and require a token.
  • Avoid exposing browser control over LAN (0.0.0.0) and avoid Funnel (public).
Related: