Connect iCloud Calendar to Claude and ChatGPT
Multi Calendar connects iCloud calendars to Claude and ChatGPT with an app-specific password, never your Apple Account password.
For the calendars of your Apple Account, added with its email.
The AI apps' own connectors
- ChatGPT's iCloud Calendar plugin connects your primary Apple Account email with an Apple app-specific password. Read on 3 November 2026.
- ChatGPT's release notes say its iCloud Calendar plugin checks your schedule and updates calendar events. Read on 3 November 2026.
Connect it
At AppleApple makes an app-specific password only once two-factor authentication is on.
The link opens Apple in a new tab.
- 1
Sign in at account.apple.com.
- 2
In Sign-In and Security, select App-Specific Passwords.
- 3
Select Generate an app-specific password and follow the steps.
Apple shows it once - leave that page open until Lumman asks for it.
Add it to
- 4Add to ClaudeOpens claude.ai - press Connect there.
- 5
Sign in, add your iCloud calendar and approve Claude in the window Claude opens - paste the app-specific password when it asks
- 6
Ask Claude about your week
- 4
Run in Claude Code
/plugin marketplace add lumman-lab/multi-calendar/plugin install multi-calendar@multi-calendarRun the first, then the second.
- 5
Sign in, add your iCloud calendar and approve Claude Code on the Lumman page your browser opens - paste the app-specific password when it asks. If none opens, run /mcp and choose multi-calendar.
- 6
Ask, or run
/multi-calendar:week
Works fully on ChatGPT Business, Enterprise and Edu.
- 4
Copy the address
- 5Open ChatGPT plugins
Press +, choose Add custom MCP server, name it Multi Calendar, paste the address, choose OAuth, tick the box and press Create as a plugin.
- 6
Install it, then sign in, add your iCloud calendar and approve on the Lumman page it opens - paste the app-specific password when it asks. In a chat, type @ and choose Multi Calendar.
- 4
Add to
~/.cursor/mcp.json - 5
Sign in, add your iCloud calendar and approve Cursor on the Lumman page Cursor opens - paste the app-specific password when it asks
Streamable HTTP, OAuth 2.1 with dynamic client registration. No key or client id.
- VS Code
Run MCP: Add Server, choose HTTP, paste the address and name it multi-calendar.
- Gemini CLI
gemini extensions install https://github.com/lumman-lab/multi-calendarIts first call opens Lumman's sign-in; /mcp auth multi-calendar opens it again.
- Antigravity
agy plugin install https://github.com/lumman-lab/multi-calendarRun /mcp, open multi-calendar_multi-calendar and choose Authenticate; approve on the Lumman page, then paste the code Antigravity shows back into it.
Free for every calendar you connect. Any number of booking pages and circles for $50 a year or $5 a month.
Reach and limits
- Find free time across it and every other calendar you add.
- Create, move and cancel events.
- Share booking links and a booking page, run group polls, and find a time with the people in a circle.
- Apple sends a meeting's invitations, updates and cancellations itself, from Apple's own address under your name.
- Answer an invitation in an iCloud calendar from its letter or in Apple's Calendar app - Multi Calendar answers none there.
- An event keeps no privacy, out of office, focus time or video link, and shows only as busy or free.
- Changing your Apple Account password ends every app-specific password. Make a new one and reconnect.
If it refuses
- iCloud refused this password. Use an app-specific password, not your Apple Account password, and check the address.
- We could not reach Apple's calendar server. Try again.
Connection
- Calendar server
- caldav.icloud.com
- Login
- Your Apple Account email and the app-specific password
- Check
- Apple's calendar server accepts the password before the account is added
Your data
- Stored
- The app-specific password, encrypted under a key held outside the database
- Calendars
- No copy kept - read from the calendar on each call
- Removing it
- Disconnecting deletes our copy of the password, which works until you delete it at account.apple.com under App-Specific Passwords.
Tools
- Offered
- All 21 - events_respond answers no invitation, and events_cancel cancels only an event the account organises
Everything else
Multi Calendar's address, sign-in, limits and every tool: Multi Calendar's technical details.