The AddCal MCP server lets an AI assistant work with your calendars directly. Connect AddCal to Claude, ChatGPT, Cursor, VS Code, or any other MCP client, then ask in plain language: the assistant creates and updates events, checks RSVPs, and pulls analytics for you. MCP (Model Context Protocol) is an open standard AI assistants use to connect to other apps.
The MCP server is included on every plan at no extra cost. The assistant acts as you, limited to your team and to what your plan already allows.
How connecting works
Every client connects to the same server URL:
https://addcal.co/mcp
Add that URL to your assistant as a custom connector or MCP server. The steps differ per client (Cursor and VS Code can install it in one click), so follow the MCP server setup guide for yours.
The first time the assistant connects, your browser opens an AddCal page titled Authorize followed by the app's name. It shows the account and team the app will act on, and what it will be able to do.
Click Authorize. The app is now connected. There is no API key to copy or paste.
Authorizing gives the app full access to your AddCal account, including attendee names and email addresses, so only connect clients you trust. If a client cannot sign in this way, it can use an API token instead (see Developer API and Dynamic Links).
What the assistant can do
Find things by name. Search across your calendars, collections, events, and RSVPs, so you can say "the product launch" rather than looking up an id.
Calendars and collections. List and create calendars, and list and create calendar collections.
Events. List, view, create, update, duplicate, and delete events. Before creating a repeating event, the assistant can preview the exact dates a rule produces so you can check them. It can also list the tags already in use and reuse them, so you do not end up with near duplicates like "Austin" and "austin".
Attendees. Read RSVPs for an event, record an RSVP, read and send calendar invites, and list the people subscribed to a calendar.
Analytics. Page views and calendar adds for an event, a calendar, or your whole team, broken down over time and by referrer, country, device, calendar provider, and UTM parameter.
External calendar sync. List the external iCal feeds connected to your calendars with their sync status, and ask for a feed to sync now.
Plan and usage. Check your plan, current usage, and limits.
For every tool and its parameters, see the MCP tool reference.
What you can ask
"Add a yoga class to my Community calendar every Tuesday at 6pm Sydney time until December. Show me the dates before you create it."
"How many people said yes to the product launch, and who said maybe?"
"Which referrers drove the most calendar adds on my Webinars calendar over the last 30 days?"
"My public holidays feed has stopped updating. Check its sync status and retry it."
Actions that email people or cannot be undone
Sending a calendar invite and recording an RSVP both email a real person, and deleting an event is permanent (deleting the first event of a recurring series deletes every instance). These actions are flagged as destructive, so your assistant asks you to confirm before running them. To record an RSVP without emailing the attendee, ask the assistant to skip the confirmation email.
Everything the assistant does is done as you and shows up in your account like any other change.
Plans and limits
Tools follow the same plan rules as the rest of AddCal:
Calendar invites are a Business plan feature.
Calendar collections, requesting an external calendar sync, and paid event options (such as a passcode or a redirect after adding) need a paid plan.
On the free plan, analytics return headline totals only. Detailed breakdowns need a paid plan.
When something is not included in your plan, the assistant tells you what you would need to upgrade rather than retrying. See Free plan limits and Managing your subscription, payments & invoices.
A requested external calendar sync runs in the background, and each feed can be synced this way at most once a minute. The assistant checks the feed's status afterwards to see whether it worked. The feed stays the source of truth, so edits the assistant makes to events that came from a feed are overwritten on the next sync. See Sync an external calendar.
If you belong to more than one team, the assistant works in your current team by default. Name the team in your request to work in another one.
Disconnect an assistant
Open API Tokens in your account settings (
/user/api-tokens).Under Connected Applications, find the app. Each one shows when you authorized it and when it was last used.
Click Revoke, then Revoke Access to confirm.
The app loses access immediately and has to be authorized again to reconnect. If you connected with an API token instead, delete that token on the same page.
You can also sign out every connected app at once when you change or reset your password. See Security and your data.