CalendarPA MCP server
CalendarPA has an MCP server, so an AI assistant such as Claude or ChatGPT can work with your CalendarPA account. Once it is connected, the assistant can see your booking types and bookings, find open times, and book, reschedule or cancel meetings for you. It signs in with your CalendarPA account, so there is no API key to copy. Every plan can connect, the Free plan included.
Server URL
https://calendarpa.com/api/mcpPaste this address exactly as shown, including /api/mcp.
Connect from Claude
- In Claude, open Customize, then Connectors.
- Click + Add, then Add custom connector.
- Name it CalendarPA, paste the server URL and click Continue.
- Click Continue past the sign-in settings Claude detects.
- Under OAuth client, choose Register automatically, then click Add.
- Sign in to CalendarPA when asked and approve the permissions.
- In a chat, click +, then Connectors, and turn CalendarPA on.
On a Claude Team or Enterprise plan, an owner adds the connector under Organization settings, then Connectors, and each member then connects it from Customize, then Connectors.
These steps follow Claude's help article on custom connectors. Claude may rename its menus.
Connect from ChatGPT
- In ChatGPT, open Plugins.
- Select the plus button, then Add custom MCP server.
- Name it CalendarPA and, under Connection, paste the server URL.
- Choose OAuth for authentication, review the warning and select I understand and want to continue.
- Select Create as a plugin, then sign in to CalendarPA and approve the permissions.
- In a new chat, type @ and pick CalendarPA.
Whether your ChatGPT account can add a custom MCP server is set by ChatGPT's own account and workspace policies.
These steps follow OpenAI's guide to connecting an MCP server. ChatGPT may rename its menus.
The three permissions
When you sign in, CalendarPA asks you to approve three permissions. Each one covers only the tools listed beside it.
- View your booking types: list your booking types and find their open times.
- View your bookings and booking details: list your bookings and read one booking.
- Create and cancel bookings on your behalf: book, reschedule and cancel.
No permission an assistant is given lets it refund a payment.
What the assistant can do
| Tool | What it does | Type |
|---|---|---|
whoami | The account it is connected to: name, email, username, plan and time zone. | Read |
list_booking_types | Your live booking types, with title, length, location options and price. | Read |
find_available_times | Open times for one booking type, as your booking page offers them. Up to 60 days per call. | Read |
list_bookings | Bookings you host, plus round-robin bookings assigned to you. Can filter by status, date created or invitee email. | Read |
get_booking | One booking's time, status, invitee, location and meeting link. | Read |
create_booking | Books a time that find_available_times offered. The invitee gets the usual confirmation and the meeting goes on your calendar. | Write |
reschedule_booking | Moves a booking you host to a new time. | Write |
cancel_booking | Cancels a booking you host and tells the invitee. For a booking paid by card the payment is kept; credits used to pay go back. | Write, destructive |
What it can't do
- Book a paid booking type.
- Move or cancel a spot in a group session.
- List bookings you co-host.
- Refund a payment.
Plans
The MCP server works on every plan, the Free plan included. If an action uses a feature your plan doesn't include, such as recurring bookings, the assistant is told which plan has it.
Limits
- Up to 300 tool calls a minute per connection, within 1,000 a minute per account.
- Finding open times reads your calendars live, so it is limited to 30 calls a minute per account.
- Over a limit, the assistant is told how many seconds to wait before trying again.
- A result larger than 100 KB is refused rather than cut short, so the assistant narrows its request.
- Access lasts 1 hour at a time and can be renewed for up to 90 days without use. If the connection stops working, connect it again.
Disconnect
In CalendarPA, go to Settings, then Integrations, find the app under Connected Apps and click Disconnect. Access stops at once: the assistant's next request is refused.
Privacy
The assistant can reach only your own account, and only what the permissions you approved allow. What Claude or ChatGPT does with what it reads is covered by their own privacy terms; ours is the Privacy Policy.
For developers
The server speaks MCP over Streamable HTTP and signs in with OAuth, using PKCE and dynamic client registration. Its protected resource metadata is at /.well-known/oauth-protected-resource/api/mcp. The REST API is documented in the API docs.