How to Add a Custom MCP Connector to Grok on Mac
Give xAI Grok direct access to your Mac apps — Mail, Calendar, Contacts, Teams, OneDrive, and 230+ tools. A custom MCP connector (Bring Your Own MCP) over the encrypted Cloud Relay — your data never leaves your Mac.
What This Lets You Do
Grok runs in the cloud, but your email, calendar, and Teams chats live on your Mac. Grok added Bring Your Own MCP custom connectors in May 2026, so with LMCP plus the Cloud Relay, Grok can call tools that run directly on your Mac — over an encrypted WebSocket tunnel — and the data stays local.
From Grok you can ask:
- “Summarize my unread emails from this week”
- “What’s on my calendar today?”
- “Search emails about the Q3 budget”
- “Summarize the engineering Teams channel from yesterday”
Grok sends the request to LMCP’s backend, the backend forwards it through the encrypted tunnel to your Mac, your Mac executes the tool locally (Mail.app, Calendar via EventKit, Teams via local cache), and the result returns to Grok.
Privacy Story
Cloud Data Forwarding is off by default and opt-in per machine. When off, the connector's tools/list advertises only setup_install (onboarding) — data tools are not listed until you enable forwarding.
When you turn it on, your data still comes from your Mac — nothing is stored in the cloud. The bytes transit through the encrypted tunnel between your Mac and the LMCP backend, but they’re never persisted server-side. Turn it off any time and Grok instantly loses access to data tools.
What You Will Need
- macOS 12 (Monterey) or later — Apple Silicon or Intel
- A Grok account on a paid tier — custom connectors (“Bring Your Own MCP”) are a paid-tier feature
- An email address — used to register your tunnel and recover access
How to Connect Grok to Your Mac
Connect Grok to your Mac
grok.com/connectors- 1
Install LMCP on your Mac
Download LMCP from local-mcp.com and run the installer — it installs Local MCP to Applications and auto-configures your AI clients in ~30 seconds.
- 2
Turn on the Cloud Relay
Click the LMCP menu bar icon → Web AIs · Via Cloud Relay. It shows Connected. Toggle Cloud Data Forwarding ON (off by default for privacy), then click Copy URL next to the connector token — this is a tokenized URL like .
- 3
Open Grok’s connectors
Go to grok.com/connectors, click New Connector, and choose Custom (Bring Your Own MCP).
- 4
Add the connector
Grok’s form has only Name and Server URL — no token field, so the token travels in the URL. Set Name: and Server URL: paste the tokenized URL you copied (), then click Add Connector. Grok probes the URL and discovers your tools.
- 5
Enable it in a chat
Start a new chat, enable the LMCP connector, and ask: “List my email accounts.” Keep this connector private — the URL contains your token.
Steps verified 2026-07-14. 100% local · you confirm anything it sends · free.
Grok has no separate OAuth or authorization step — the token in the URL is the credential. Keep the connector private: anyone with the URL can use it until you disconnect it or toggle Cloud Data Forwarding off. You can rotate the token anytime from LMCP Settings.
Try It in a Chat
Open a new conversation in Grok with the LMCP connector enabled. Then ask in plain language:
- “List my email accounts”
- “What meetings do I have today?”
- “Show me the latest messages in the engineering Teams channel”
Grok routes the request through the Cloud Relay to your Mac, which executes the tool and returns the result — usually in under 2 seconds.
What Tools Are Available?
With Cloud Data Forwarding on, Grok sees the same 230+ tools as the local lmcp connector:
- Mail (Mail.app + Outlook): list, read, search, send, reply, move, save attachments
- Calendar: list events, create, delete, check availability
- Contacts: search, list, get details
- Microsoft Teams: list chats, read messages, channel messages (no Graph API needed)
- OneDrive: list, read, write, move, delete, search files
- Notes & Reminders: list, search, create, complete
- Messages: read iMessage chats
- OmniFocus: list tasks, projects, complete, search
- Word, Excel, PowerPoint, PDF: read and create
- Finder & Safari: search files (Spotlight), list folders, bookmarks
Turning It Off
Open the LMCP menu bar popover → Web AIs section, toggle Cloud Data Forwarding back to OFF. The change is instant: Grok immediately loses access to data tools. Your tunnel stays connected for onboarding (setup_install), but no data flows through.
Troubleshooting
Grok shows “0 tools” or only setup_install
Two causes. (1) Your connector URL is missing the ?token= — without it, the session is unbound and only setup_install is advertised. Re-add the connector using the full tokenized URL from Copy URL (Step 3). (2) Cloud Data Forwarding is OFF — toggle it ON in the Cloud Relay section. If the tool list doesn’t refresh, remove and re-add the connector in grok.com/connectors to force a fresh discovery.
Connector shows “Connected” but tools fail
Make sure LMCP is running (menu bar dot should be green) and Cloud Data Forwarding is ON. If the token is no longer valid, copy a fresh URL via Copy URL from the Cloud Relay section and re-add the connector.
Custom connector option not available in Grok
“Bring Your Own MCP” custom connectors require a paid Grok tier. If you only see prebuilt connectors, upgrade your Grok plan, or use LMCP with a local client (Claude Desktop, Cursor, Claude Code) that connects directly without the Cloud Relay.
Frequently Asked Questions
How do I add a custom connector to Grok?
Install LMCP and turn on Cloud Data Forwarding in its menu-bar app, then at grok.com/connectors add a Custom connector with your tokenized LMCP URL. The token in the URL binds the session — there's no separate authorization step.
What can Grok do with my Mac?
Read your email, manage your calendar and search Microsoft Teams — requests route to your Mac and run locally, so your data isn't stored in the cloud.
Is it free, and do I need API keys?
LMCP is free and needs no API keys. Grok's custom-connector feature requires a paid Grok tier — that's an xAI requirement, not an LMCP one.