What This Lets You Do

ChatGPT runs in the cloud, but your email, calendar, and Teams chats live on your Mac. Until now there was no way to bridge them — ChatGPT couldn’t reach your Mail.app or your local Teams cache.

With LMCP plus the Cloud Relay, ChatGPT can call tools that run directly on your Mac. Ask it from any device:

“Summarize my unread emails from this week”
“What’s on my calendar tomorrow?”
“Find the Teams message where Marco mentioned the API migration”
“Draft a reply to Sarah’s email about the budget”

ChatGPT sends the request to the LMCP backend, the backend forwards it through an encrypted WebSocket tunnel to your Mac, your Mac runs the tool, and the result comes back to ChatGPT — usually in under 2 seconds.

Privacy Story

Cloud Data Forwarding is off by default and opt-in per machine. When off, the Cloud Relay only exposes setup tools (install, status, troubleshoot) — ChatGPT cannot see your data tools at all.

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 from the menu bar and ChatGPT instantly loses access.

If you prefer zero cloud transit, you can use the local lmcp connector inside Claude Desktop, Cursor, or VS Code instead — tool calls go through stdio and never touch the network. Read the privacy guide for the full breakdown.

What You Will Need

macOS 12 (Monterey) or later — Apple Silicon or Intel
ChatGPT Plus, Team, Enterprise, or Edu — the Custom Connector feature is not available on the free plan
An email address — used to register your tunnel and recover access

Step 1: Install LMCP on Your Mac

Open Terminal (Cmd+Space → “Terminal” → Enter) and run:

curl -fsSL https://local-mcp.com/install?ref=guide-chatgpt | bash

The installer downloads LMCP, creates a background service, configures local AI clients, and starts the menu bar app. Takes about 30 seconds.

Step 2: Set Up Cloud Relay

Click the LMCP icon in your menu bar (top-right corner of the screen). In the Cloud Relay section, enter your email and click Connect. The dot turns green when the encrypted tunnel is established.

This registers a unique token for your Mac on the LMCP backend. The token is what identifies your tunnel — without it, no one can route requests to your Mac.

Step 3: Enable Cloud Data Forwarding

By default, the Cloud Relay only exposes setup tools to ChatGPT — not your data. Toggle Cloud Data Forwarding in the menu bar to ON.

Confirm in the dialog. You’ll see your connector URL and token appear right below the toggle, with copy buttons for both.

Step 4: Add the Connector in ChatGPT

Open ChatGPT (web or desktop), then:

Click your profile picture → Settings
Go to Connectors (or Apps & Connectors)
Click + Add Connector (or Build a connector)
Fill in:
- Name: LMCP
- Description: My Mac apps — Mail, Calendar, Teams, OneDrive
- MCP Server URL: https://www.local-mcp.com/mcp
- Authentication: OAuth
Click Continue — ChatGPT auto-discovers our OAuth endpoints. Leave the OAuth fields empty (they get filled by Dynamic Client Registration).
Check the box “I understand and want to continue” and click Create.

Step 4b: Authorize on the popup

ChatGPT opens an OAuth login page on www.local-mcp.com. You’ll see:

Authorize ChatGPT — ChatGPT wants to access your Mac apps via LMCP. Paste your cloud token below.

Open the LMCP menu bar icon, click the Copy button next to your token, switch to the popup, paste the token, and click Authorize. The popup closes automatically and ChatGPT shows the connector as Connected.

ChatGPT then validates the connection and discovers the available tools. You should see ~90 tools listed (Mail, Calendar, Teams, OneDrive, Notes, Reminders, Office files, and more). You only do this OAuth step once — ChatGPT remembers the token for the lifetime of the connector.

Step 5: Try It

Start a new conversation in ChatGPT. Make sure the LMCP connector is enabled in the chat (the connector toggle in the input bar). Then ask:

“List my email accounts”
“What meetings do I have today?”
“Search my emails for ‘invoice’ this month”
“Show me the latest messages in the engineering Teams channel”

ChatGPT will route the request through the Cloud Relay to your Mac, which executes the tool and returns the result. You’ll see a tool call indicator in ChatGPT’s UI, and the response usually arrives in under 2 seconds.

What Tools Are Available?

With Cloud Data Forwarding on, ChatGPT sees the same 80+ 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

Use Cases

Inbox triage from your phone

You’re away from your Mac but want to triage your inbox. Open ChatGPT on your phone: “Summarize new emails from the last 24 hours, group by sender, flag anything from legal or finance.” ChatGPT calls your Mac, reads Mail.app, returns a categorized summary in seconds.

Meeting prep before walking into the room

You have a 3pm meeting and 5 minutes to prepare. From ChatGPT: “Prep me for the 3pm with Maria and Juan. Find recent emails, Teams chats, and shared docs from the last week.” ChatGPT cross-references your calendar attendees with email/Teams/OneDrive activity and gives you a context brief.

Weekly status report

Friday afternoon: “Write my weekly status report based on this week’s emails, calendar events, and Teams discussions.” ChatGPT pulls the data, generates the report, you copy-paste to Slack or send by email — from your phone if you want.

Turning It Off

Open the menu bar, toggle Cloud Data Forwarding back to OFF. The change is instant: ChatGPT immediately loses access to data tools (it’ll see the “use the local connector” message). Your tunnel stays connected for setup tools, but no data flows through.

If you want to stop everything completely, click Change next to your email in the Cloud Relay section and remove the email — the tunnel closes and your token is no longer registered to your machine.

Troubleshooting

ChatGPT says “Could not reach your Mac”

The LMCP app isn’t running, or the Cloud Relay tunnel is down. Open the menu bar — the dot should be green. If it’s orange, click it and re-enter your email. If LMCP isn’t running at all, reinstall: curl -fsSL https://local-mcp.com/install?ref=guide-chatgpt | bash.

Tools list shows only setup tools (8 instead of ~90)

Cloud Data Forwarding is OFF. Open the menu bar and toggle it ON, then refresh ChatGPT (or restart the conversation).

ChatGPT says “the connector is not authenticated”

The token is wrong or expired. Open the menu bar, copy the token again (the copy button next to Token:), and paste it back into ChatGPT’s connector settings.

What About Other AI Clients?

The Cloud Relay works with any MCP-compatible client that supports custom servers and Bearer authentication:

Claude.ai web: same flow, add as Custom Connector in Settings
Sheet add-ins: paste the URL and token in the add-in’s connector config
Custom MCP clients: any tool that can hit a JSON-RPC endpoint over HTTPS

For Claude Desktop, Cursor, VS Code, Windsurf, or Zed running on your Mac, you don’t need the Cloud Relay at all — LMCP autoconfigures the local lmcp connector during install, and tool calls go through stdio without touching the cloud. See the Claude Desktop guide for that flow.

How to Connect ChatGPT to Your Mac