Grok takes custom connectors, which is xAI's name for a remote MCP server. It wants the address and nothing else.
Add it
Open grok.com/connectors, press New connector and choose Custom. Paste the address as the MCP server URL and pick the no-authentication option. On a Business or Enterprise account an administrator adds the connector for the organization first, and then each person switches it on for themselves.
https://makehybrid.com/mcp/<your key>
Two different things called X
This is xAI's assistant reading your account through MCP. It is a different thing from the X API, which posts and reads direct messages on X itself and has keys of its own. If that is what you are after, connect the X channel instead — it has an address of its own, /x/mcp/<key>, and a reference to go with it.
Check it
Ask it to list your connected LinkedIn accounts. Your accounts back means it worked.
Questions people ask
Which transport does it want?
HTTP. This is a remote server reachable over the public internet, which is what Grok's connectors expect; there is nothing to tunnel and nothing to run locally.
Does it need a paid Grok account?
Custom connectors sit on xAI's paid tiers. If New connector does not offer Custom, that is the reason.
Can I give it only the messaging channels?
Yes — use /inbox/mcp/<key> and it has the shared inbox and nothing else.