Docs / Connect / Grok
Grok on the web cannot reach a program on your computer, so the way in is a custom connector that points at ModelBrain's hosted relay. You turn sharing on in the ModelBrain menu, add the connector in Grok, sign in once, and Grok reads and writes the same memories as Claude Desktop, Claude Code, Cursor and ChatGPT. Grok support is new. It uses the same relay and sign-in as ChatGPT. We have connected Grok on the web and confirmed a ModelBrain ping from a Grok chat; Grok's menu wording may still change.
Using more than one computer? Do this on each one, and give each a different name on your account page, because the sign-in page lists computers by name.
ModelBrain and enter the server URL https://relay.modelbrain.net/mcp. Leave any token or key field empty: the sign-in is OAuth and needs none.ModelBrain emails you each time an app is connected to a computer, so you notice a connection you did not make. Only ChatGPT and Grok can connect through the relay: the sign-in page refuses any other app.
Your Grok plan or workspace may not include custom connectors yet, or the labels have moved. Look for a connectors page that accepts your own MCP server URL.
Grok keeps the registration it made the first time. If that registration is gone from our side, the sign-in page cannot continue. In Grok, delete the ModelBrain connector and add it again with https://relay.modelbrain.net/mcp. That makes a fresh registration. Your computer does not need to change.
Grok support is new and we have not seen every address Grok uses. If you hit this, email support@modelbrain.net with the time you tried, and we can add the address.
No computer on your account has sharing turned on. On the computer you want Grok to reach, choose Connect to ChatGPT → Connect… in the ModelBrain menu, then choose Check again on the page.
A connection request lasts 10 minutes and works once. Go back to Grok and connect again.
Claude Desktop, Claude Code and Cursor run as local MCP clients and talk to your ModelBrain on your own computer with no network hop. A website such as grok.com cannot reach your computer, so Grok connects to a small hosted relay at relay.modelbrain.net, which ties the session to the computer you picked and forwards each request to it, and the answer back, over TLS.
The relay does not write what you ask Grok to remember or recall to disk. It holds only the connection state needed to keep a computer connected and a login alive (device and session identifiers, access tokens). This is the one path where your requests pass through a server ModelBrain operates while in transit.
Open the ModelBrain menu and choose Connect to ChatGPT, then Connect. In Grok on the web, open grok.com/connectors, choose New Connector, then Custom, and enter https://relay.modelbrain.net/mcp. Grok sends you to modelbrain.net: sign in, pick the computer, and choose Connect this computer. There is no code to copy.
It is new. The relay accepts Grok connections, and we have confirmed a Grok chat can reach ModelBrain, but the menu labels in Grok may differ from this guide and we have not tried every Grok plan. If a step does not match, look for the connectors page, a custom connector, and the relay URL.
Requests pass through the hosted relay while in transit, the same relay ChatGPT uses, over an encrypted connection. The relay does not write request or answer content to disk.
Choose Stop Sharing with ChatGPT in the ModelBrain menu to stop offering the computer to any hosted app, which ends every Grok and ChatGPT connection to it. To end a single connection, open your account page and choose Disconnect next to Grok. Then remove the connector in Grok.
These connect straight to your local ModelBrain.
Claude Desktop → · Claude Code → · Cursor →