Connect ChatGPT to iMessage on Mac
In short: Let ChatGPT list chats, read conversations and search messages in the Messages app on your Mac. There is no iMessage API: LMCP reads the local database.
ChatGPT can work with iMessage on your Mac once LMCP is installed and added to ChatGPT. LMCP is a local MCP server: ChatGPT can list chats, read conversations and search messages in the Messages app on your Mac. There is no iMessage API: LMCP reads the local database.
What ChatGPT Can Do with iMessage
- List your message chats (list_message_chats)
- Read a conversation with any person or group (read_messages)
- Search your messages by keyword across all conversations (search_messages)
Preview and confirmation behavior depends on the tool, platform and AI client. Check the tool requirements and review the intended action before authorizing a real call.
What You Will Need
- macOS 13+ and LMCP installed
- Full Disk Access for LMCP, so it can read the Messages database
- ChatGPT on the web in a desktop browser — MCP apps are added from Plugins; on Business/Enterprise/Edu a workspace admin may need to allow custom apps first
Connect ChatGPT to Your Mac
Connect ChatGPT to your Mac
chatgpt.com → Plugins → Add → Create MCP AppCustom MCP apps are added from Plugins in a desktop browser. On Business/Enterprise/Edu a workspace admin may need to allow custom apps first. ChatGPT flags a custom app as high-risk because it can act on your data.
- 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 web access and copy your Connection URL
Click the LMCP icon in your menu bar and find Your web AI · Cloud Relay. Make sure web access is ON (it is on after installation unless you turned it off), then open your assistant’s panel and click Copy URL.
The URL is — it carries no token and is the same for everyone; every step below that says “the URL you copied” means this one. Access is granted by approving the connection on your Mac, not by the URL. - 3
Open Plugins
Use a desktop browser at chatgpt.com — MCP apps can’t be added from the mobile or desktop apps. Click Plugins in the sidebar (or go to chatgpt.com/plugins). There is no Developer mode to turn on any more; on Business/Enterprise/Edu a workspace admin may need to allow custom apps first.
- 4
Create the MCP App
Click Add ▾ at the top right and choose Create MCP App — not “Create plugin”. In the New Plugin dialog set Name: , leave Connection on Server URL and paste the URL you copied from the LMCP menu bar (). Authentication stays on “OAuth” — leave Advanced OAuth settings empty, we auto-register. Tick I understand and want to continue (Create stays disabled until you do) and click Create.
- 5
Sign in and approve on your Mac
Create only registers the connector — it still reads “No app actions available yet”. Click Sign in with LMCP: ChatGPT opens an Authorize page on , and a dialog appears on your Mac. Click Approve there and the tool catalog loads.
If no dialog shows up, or the page says LMCP isn’t running, the approval simply expired — it only lasts 5 minutes. Click the button again; nothing needs reinstalling. - 6
Enable it in a chat
Start a new conversation and enable LMCP from the composer’s tools menu (+). Then ask: “List my email accounts” or “What meetings do I have today?”
In Settings → Plugins, Default permission decides which tools run without asking: with Allow low-risk tools, tools ChatGPT considers low-risk can run without a prompt, and the rest still ask first.
Steps verified 2026-09-27. Local tools run on your device; selected AI providers and connectors receive requested content. Review each tool’s permissions and approval behavior.
More detail: the full ChatGPT guide.
Try It Out
Start a new chat, enable LMCP via + → More → LMCP, then ask:
Summarize my last conversation with Mom.
Did anyone text me about dinner tonight?
Find the address Sarah sent me last week.
Troubleshooting
A conversation is missing
If a conversation isn’t synced to this Mac, it isn’t in the local database.
Can the assistant send iMessages without my approval?
The Mac send_message tool returns a preview on its first call; a subsequent call with confirm=true sends the message. Review the recipient and content first.
The connector shows “No app actions available yet”
Normal — that panel doesn’t list tools. Enable LMCP in a chat via + → More → LMCP and it works.
ChatGPT says “Could not reach your Mac”
The LMCP app isn’t running, or the Cloud Relay tunnel is down. Open the LMCP menu bar — the dot should be green and Cloud Relay should read Connected. If LMCP isn’t running at all, download and reinstall it.
ChatGPT says “the connector is not authenticated”
The OAuth approval is no longer valid. Connect again — click Sign in with LMCP — and approve in the dialog that opens on your Mac. The connector URL stays the same, so there is nothing to copy or re-add.
Related Guides
Comments
Questions and experiences welcome — comments are reviewed before they appear.