Read AddEvent calendars, events, RSVPs and subscribers; create and update calendars and events. Hosted by usefulapi — connect from Claude, Cursor, or any MCP client.
Team and Enterprise: an Owner adds the connector for the organization first.
Run this command, then run /mcp in Claude Code to log in:
Add to Cursor or add this to ~/.cursor/mcp.json:
{
"mcpServers": {
"addevent": {
"url": "https://addevent.usefulapi.io/mcp"
}
}
}Add to VS Code or add this to .vscode/mcp.json:
{
"servers": {
"addevent": {
"type": "http",
"url": "https://addevent.usefulapi.io/mcp"
}
}
}Other MCP clients (Windsurf, Cline, Zed and more): add the URL as a remote MCP server (Streamable HTTP). The client then opens the login page in your browser. Do not add an Authorization header: see Before you connect.
The login page asks for your AddEvent API key.
Find it in the AddEvent dashboard under Account settings. API access needs a paid AddEvent plan. The key gives full access to your account's calendars and events; it is used only to call the AddEvent API on your behalf and is never shown to anyone.
Add only the URL. Do not add an Authorization header or an API key to the client config. The server signs you in with OAuth: the login page asks for your AddEvent API key. If the config has such a header, remove it: some clients then send that header instead of the login token, and every call fails with 401.
| Tool | Type | What it does |
|---|---|---|
addevent_list_calendars | read | List calendars List the account's calendars (newest first by default) with id, title, timezone, whether it is the default calendar, landing-page links and counts of events and subscribers. GET /calendars. |
addevent_get_calendar | read | Get calendar One calendar by id: title, timezone, week start, template ids, subscriber and event counts, links, custom data. GET /calendars/{id}. |
addevent_create_calendar | write | Create calendar WRITE: creates a new calendar in the AddEvent account (a new, empty calendar; nothing existing is changed and nobody is notified). Needs a title. POST /calendars. |
addevent_update_calendar | write | Update calendar WRITE: changes fields of an existing calendar (only the fields you pass; the rest stay). Title, description and timezone changes show on its landing page and can reach people who subscribe to the calendar feed. Not reversible by this server (no previous values are kept), so read the calendar first. PATCH /calendars/{id}. |
addevent_list_events | read | List events Search the account's events (newest created first; by start time when a date filter is used): title, start/end, timezone, location, RSVP settings and stats, landing-page links. Filter by calendar, event ids, text, date window or a custom_data pair. GET /events. |
addevent_get_event | read | Get event One event by id (evt-...): all fields incl. description, organizer, reminder, recurring rule, RSVP settings and stats, custom data and share links. GET /events/{id}. |
addevent_create_event | write | Create event WRITE: creates a new event on a calendar (the account's default calendar if calendar_id is omitted). Creates a public event landing page and share links; it does not e-mail anyone, though people subscribed to that calendar's feed will see the event on their next sync. Needs title and datetime_start. POST /events. |
addevent_update_event | write | Update event WRITE: changes fields of an existing event (only the fields you pass; the rest stay). The change goes live on its landing page and share links, and people who subscribed to the calendar or added the event with a live link are updated on their next calendar sync, so a time or location change can notify real people. No previous values are kept: read the event first. PATCH /events/{id}. |
addevent_list_rsvp_attendees | read | List RSVP attendees List RSVP attendees (personal data: e-mail addresses and the answers they gave on the RSVP form). Filter by calendar, event or response (going/maybe/not-going). Paged, 20 at most per page: read only what the task needs. IP address and coordinates are removed from the reply. GET /rsvps. |
addevent_get_rsvp_attendee | read | Get RSVP attendee One RSVP attendee by id (personal data: e-mail and form answers; IP address and coordinates removed). GET /rsvps/{id}. |
addevent_create_rsvp_attendee | write | Create RSVP attendee WRITE: adds ONE RSVP attendee (one e-mail address, personal data) to an event. This server never asks AddEvent to send the confirmation or organizer notification e-mails, but the event's own reminder and follow-up e-mails (if the event has them) will later go to this address, so only add someone who really RSVP'd. The e-mail must be unique per event. POST /events/{id}/rsvps. |
addevent_update_rsvp_attendee | write | Update RSVP attendee WRITE: changes ONE RSVP attendee (email, response or form answers; only the fields you pass). The event's reminder and update e-mails go to the e-mail address stored here, so changing it redirects those e-mails to that person. This server never triggers the confirmation or organizer notification e-mails. PATCH /rsvps/{id}. |
addevent_list_calendar_subscribers | read | List calendar subscribers List people subscribed to the account's calendars (personal data: the form answers they gave, such as name and e-mail; calendar app type, sync status). Paged, 20 at most per page. IP address and coordinates are removed. GET /subscribers. |
addevent_get_calendar_subscriber | read | Get calendar subscriber One calendar subscriber by id (personal data; IP address and coordinates removed). GET /subscribers/{id}. |
addevent_list_rsvp_forms | read | List RSVP forms The account's RSVP forms (id, name), newest first. Use the id as rsvp_form_id on an event. GET /events/rsvp-forms. |
addevent_list_event_templates | read | List event landing page templates The account's event landing page templates (id, name), newest first. Use the id as landing_page_template_id on an event. GET /events/templates. |
addevent_list_calendar_templates | read | List calendar templates The account's calendar landing page templates or embeddable calendar templates (id, name), newest first. Use the id as landing_page_template_id / embeddable_calendar_template_id on a calendar. GET /calendars/templates. |
addevent_list_timezones | read | List timezones Timezone names AddEvent supports (use them as the timezone of events and calendars), with current UTC offset. Optional text filter on the name. GET /timezones. |
addevent_usage_status | Usage status (free-tier meter) Report the caller's current free-tier usage this month: calls used, monthly limit, remaining, and whether the cap is reached. Read-only; does not count against the meter. | |
addevent_request_feature | Request a missing feature Tell usefulapi that the user needs something the AddEvent tools cannot do yet (a missing tool, field or filter). Call it only when the user asks for something none of the tools can do, and tell the user that you send the request. Do not call it for errors or for normal requests. Do not include personal data, credentials or customer records. Stored with the product name and the client type (for example Claude or Cursor), without the user's account. At most 5 requests per day. Does not count against the meter. | |
addevent_upgrade | Upgrade to Pro (unlimited) Subscribe to the Pro plan for UNLIMITED AddEvent tool calls (the free tier caps monthly usage). Choose monthly ($9/month) or yearly ($90/year — 2 months free) billing. Returns a Stripe Checkout link to open in your browser; after payment your account upgrades automatically. Does not count against the meter. | |
addevent_cancel_subscription | Cancel the Pro subscription Cancel the caller's AddEvent Pro subscription at the end of the paid period (no refund for the current period; unlimited calls continue until then, then the free tier applies). Requires confirm: true. Run addevent_upgrade later to undo the cancel before the period ends. Does not count against the meter. |
| Plan | Price | Limit |
|---|---|---|
| Free | $0 | 100 tool calls / month |
| Proper account | $9/mo · $90/yr | Unlimited |
Pro covers this AddEvent server only. Subscribe with addevent_upgrade (it returns a Stripe Checkout link). Cancel any time with addevent_cancel_subscription: Pro continues to the end of the paid period, with no refund for the current period, and running addevent_upgrade before then undoes the cancel. Or write to [email protected].
No. usefulapi is an independent service. It is not affiliated with or endorsed by AddEvent. The server calls the AddEvent API with your own AddEvent access, so it sees only the data that your account can see.
The login page asks for your AddEvent API key. See Before you connect for where to find it.
No. Add only the URL. Do not add an Authorization header or an API key to the client config. The server signs you in with OAuth: the login page asks for your AddEvent API key. If the config has such a header, remove it: some clients then send that header instead of the login token, and every call fails with 401.
The login stores them encrypted in the authorization grant of your connection. The server uses them to call the AddEvent API for you and to derive a private account id for usage metering. usefulapi does not show them on any page or in any reply. To stop all access, remove the connector and change or delete these credentials in AddEvent.
Yes, if you approve it. 6 of the 18 AddEvent tools can create or change data. The other 12 are marked read-only. Most MCP clients ask you to approve a tool call before it runs.
The Free plan gives 100 tool calls / month. Pro costs $9/mo or $90/yr, with unlimited tool calls, for this AddEvent server only. Run addevent_usage_status to see how many calls you used.
Ask the AI to run addevent_upgrade: it returns a Stripe Checkout link. To cancel, run addevent_cancel_subscription. Pro continues to the end of the paid period.
Tell the AI what you wanted to do. It can send the request with addevent_request_feature. We store the text with the server name, the type of AI client and the tool you tried, not with your account, and read every request when we plan new tools. You can send up to 5 requests per day.
Any client that supports remote MCP servers (Streamable HTTP) with OAuth login: Claude (web and desktop), Claude Code, Cursor, VS Code, Windsurf and others.
This is a Model Context Protocol endpoint — meant to be connected from an AI client, not opened in a browser. An invalid_token response at the URL is the auth gate working as designed; clients authenticate automatically.