Grok Chrome Bridge

Chrome extension that lets Grok Build attach to this Chrome profile — the one where you mark the extension Active — instead of launching an empty isolated browser.

Grok then sees that profile’s tabs, cookies, and logins.

Why this exists

chrome-devtools-mcp (what Grok Build uses) starts a throwaway Chrome profile by default. --autoConnect can attach to a running Chrome 144+ instance, but it always picks Chrome’s default profile.

This extension flips that: you choose the profile. Mark it Active, Grok connects there.

How it works

This Chrome profile          Native host                 Grok Build
┌──────────────────┐     ┌─────────────────────┐     ┌──────────────────┐
│ Grok Chrome      │ NM  │ Writes              │     │ MCP wrapper      │
│ Bridge · Active  │────▶│ ~/.grok/            │────▶│ chrome-devtools  │
│                  │     │ chrome-bridge.json  │     │ --ws-endpoint    │
└──────────────────┘     └─────────────────────┘     └──────────────────┘

The extension cannot turn remote debugging on by itself. Chrome 144+ does that from chrome://inspect/#remote-debugging.

Piece	Path	Role
Extension	`extension/`	MV3 popup + Active toggle
Native host	`native-host/`	Finds this Chrome’s DevTools port
MCP wrapper	`mcp/`	Starts `chrome-devtools-mcp` against that endpoint

Install

Needs: macOS, Python 3, Node.js 20+, Chrome 144+.

git clone https://github.com/davidsolheim/grok-chrome-bridge.git
cd grok-chrome-bridge
./scripts/install.sh

That registers the native host com.grokchromebridge.host for Chrome, Chromium, Brave, and Edge.

To also point Grok Build at this wrapper (rewrites only [mcp_servers.chrome-devtools] in ~/.grok/config.toml):

./scripts/install.sh --configure-grok

Then:

Open chrome://extensions → Developer mode → Load unpacked → the repo’s extension/ folder.
Confirm the ID is kaelkjfngeajflpnjpgoijcjjcalnphi.
Open chrome://inspect/#remote-debugging and enable remote debugging.
Click the extension icon → Active.
Restart Grok Build so MCP reconnects.

node mcp/grok-chrome-mcp.mjs --status

Daily use

Open the Chrome profile you want Grok to use.
Click Active.
Keep that Chrome window open.
Work in Grok as usual.

Only one profile should be Active. Activating another profile takes over.

Security

This is a local browser-control tool. An Active profile plus Chrome remote debugging lets any local process attach to that browser.

Discovery file is mode 0600 and holds loopback DevTools URLs only — not tab URLs, cookies, or account names.
Native messaging allowed_origins is locked to this extension’s ID.
The host only probes 127.0.0.1.
manifest.json key is a public key (stable unpacked ID), not a private key.

Read SECURITY.md before using this on a profile that has sensitive sessions.

Troubleshooting

Symptom	Fix
Popup: native host not found	`./scripts/install.sh`, then reload the extension
Remote debugging Off	`chrome://inspect/#remote-debugging` → enable → Refresh
`--status` says no Active profile	Toggle Active in the profile you want
Grok still opens a blank Chrome	Confirm `~/.grok/config.toml` chrome-devtools command is `node` + this wrapper; restart Grok
Wrong profile	Activate the extension in the desired profile (storage is per-profile)
Extension ID changed	Don’t remove the `key` in `manifest.json`; re-run `install.sh`

Develop

python3 tests/test_native_host.py
node tests/test_mcp_wrapper.mjs

See CONTRIBUTING.md and shared/protocol.md.