AddCal

co.addcalPublished by addcal.coOfficial publisherv1.0.1Updated Oct 24, 2026

Publish public calendars and events others subscribe to: RSVPs, feeds and add-to-calendar links.

VerifiedStreamable HTTPWeb executableProductivity & WorkflowCommunication & CollaborationData & Analytics

Overview

AI-generated overview

Remote AddCal MCP server for publishing public calendars and events that others subscribe to, with RSVPs, invites, feeds and analytics.

What you can do
  • Search across calendars, collections, events and RSVPs to find the ids other tools need
  • List and create calendars, and bundle several calendars into a public collection with one subscribe link
  • List, create, update, duplicate and delete events, including recurring series, and preview recurrence dates before creating them
  • Read subscribers and RSVPs, record RSVPs, and send event invites by email
  • Read analytics on add-to-calendar clicks and team usage
When to use it
Use it when you publish a calendar an audience follows — a class timetable, fixture list, release schedule or conference programme — and want an assistant to manage those events, subscribers and RSVPs. It is not meant for reading or writing your own personal schedule.
Requirements
A remote streamable HTTP endpoint; nothing to install and no API key. OAuth 2.1 with PKCE and dynamic client registration: the client registers itself and you approve it in a browser, receiving a token scoped to your team. Some clients need a paid plan to add custom connectors. Features such as collections, invites and analytics depend on your AddCal plan.
Before you install
Three tools are marked destructive and need an explicit confirm parameter: send-event-invite and create-rsvp email a real person and cannot be recalled, and delete-event is permanent, removing every instance of a recurring series. Subscriber and RSVP listings return personal data such as names and emails. The token can reach exactly what you can reach in your team; revoke connected clients from Settings.

Installation

In SourceWeft

  1. Open AddCal in the dashboard and add it to a workspace.
  2. Connect the required credentials. They are stored privately and never shown on public pages.
  3. Enable the server for the chats that should use its tools.

Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.

Use with an agent

Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.

Read https://sourceweft.com/mcp/co.addcal%2Faddcal/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config. The client completes OAuth sign-in on first connect.

{
  "mcpServers": {
    "addcal": {
      "type": "http",
      "url": "https://addcal.co/mcp"
    }
  }
}

README

AddCal MCP Server

[smithery badge] [MCP Registry]

A remote Model Context Protocol server for AddCal. Connect Claude, ChatGPT, Cursor or any MCP client and manage the calendars other people subscribe to.

https://addcal.co/mcp

No install, no API key. It is a hosted streamable HTTP server and authentication is OAuth.

This is not a Google Calendar MCP

Almost every calendar MCP server does the same job: it reads and writes your own schedule. Useful, and well covered already.

AddCal is the other side of the calendar. It manages the events you publish for an audience: a class timetable, a fixture list, a release schedule, a conference programme. The people receiving those events never get an invite. They subscribe to a feed, or they click an add-to-calendar link, and the event lands in whichever calendar app they already use.

That difference shows up in the tools. There is no accept-invite, because nobody is invited. There is list-subscribers, get-analytics and create-calendar-collection, because the questions you ask about a published calendar are how many people follow it and whether anyone actually added the event.

Use a Google Calendar MCP to run your day. Use this one to run a calendar other people follow.

Quick start

Pick your client. Cursor and VS Code install in one click.

[Add to Cursor] [Add to VS Code]

Claude Code

bash
claude mcp add --transport http addcal https://addcal.co/mcp

Then run /mcp inside Claude Code to sign in.

Claude Desktop and claude.ai

Settings, Connectors, Add custom connector, then paste https://addcal.co/mcp. Custom connectors need a paid plan.

ChatGPT

Settings, Apps & Connectors, Advanced, turn on Developer mode, then add https://addcal.co/mcp as a connector. Requires a paid plan on the web app.

Anything else

Any client that speaks streamable HTTP with OAuth. Windsurf, Goose, Zed and the JetBrains AI Assistant all take a remote MCP URL.

json
{  "mcpServers": {    "addcal": {      "type": "http",      "url": "https://addcal.co/mcp"    }  }}

Authentication

OAuth 2.1 with PKCE and dynamic client registration. There is no API key to copy and paste.

Your client registers itself, you approve it in a browser, and it receives a token scoped to your team. It can reach exactly what you can reach, no more. Revoke any connected client from Settings, API.

What you can ask for

What have I got on next week?Create a team standup every weekday at 9am and show me the dates first.Who has RSVPed yes to the launch party?Duplicate last month's workshop into March.Which of my events got the most add-to-calendar clicks?

Tools

19 tools. RO is read only. Required parameters are marked *.

Search

ToolParameters
searchROquery*, limit, team_id

One call across calendars, collections, events and RSVPs, returning the ids every other tool needs. Start here whenever something is named rather than identified.

Calendars

ToolParameters
list-calendarsROsearch, limit, team_id
create-calendarname*, description, timezone, team_id

Collections

A collection bundles several calendars behind one public page and subscribe link.

ToolParameters
list-calendar-collectionsROteam_id
create-calendar-collectionname*, calendar_ids*, description, allow_subscriber_selection, team_id

Subscribers

ToolParameters
list-subscribersROcalendar_id*, status, search, limit

Returns personal data. Names and emails exist only for calendars that ask subscribers for details, so many rows are anonymous.

Events

ToolParameters
list-eventsROcalendar_id, search, range, start_date, end_date, limit, team_id
get-eventROevent_id*
create-eventcalendar_id*, title*, date_start*, date_end*, timezone, description, location, is_all_day, is_draft, has_rsvp, recurrence_rule, series_title, reminder_before
update-eventevent_id*, title, description, location, date_start, date_end, timezone, is_all_day, is_draft, has_rsvp, recurrence_rule, reminder_before
duplicate-eventevent_id*, target_calendar_id, title, date_start, date_end
delete-eventdestructiveevent_id*, confirm*, notify_invitees
preview-recurring-datesROrecurrence_rule*, date_start*, date_end*, timezone, is_all_day, count

Recurrence uses RFC 5545 rules without the RRULE: prefix, such as FREQ=WEEKLY;BYDAY=MO;COUNT=10. Run preview-recurring-dates before creating a series to check the dates land where you expect.

RSVPs

ToolParameters
list-rsvpsROevent_id*, response_type, search, limit
create-rsvpdestructiveevent_id*, name*, email*, response_type*, confirm*, custom_fields, send_confirmation

create-rsvp emails the attendee by default. Set send_confirmation to false to record an RSVP silently.

Invites

ToolParameters
list-invitesROevent_id*, status, search, limit
send-event-invitedestructiveevent_id*, email*, confirm*

Account

ToolParameters
get-analyticsROcalendar_id, event_id, start_date, end_date, timezone, unique_only, include_series, team_id
get-team-usageROteam_id

Destructive tools

Three tools are annotated destructive, and all three require an explicit confirm parameter:

  • send-event-invite and create-rsvp email a real person. That cannot be recalled.
  • delete-event is permanent, and deleting a recurring event removes every instance in the series.

A well-behaved client surfaces these for approval before running them. Check the name and address when your assistant asks.

Plans and limits

The server is included on every plan, and the tools respect whatever your plan already allows. Collections, calendar invites and analytics stay gated to the plans that include them. When a tool hits a limit it explains why rather than retrying.

Links

About this repository

AddCal's MCP server is hosted, so there is nothing here to install or run. This repository holds the published server.json manifest and the documentation for the remote endpoint. The implementation lives in the main AddCal application.

Found a problem with a tool, or want one that does not exist yet? Open an issue.

Source: README.md at commit 9fd4f59

Tools

0
This server asks you to sign in, so SourceWeft could not read its tools without an account and has not indexed them. What a connected account sees can depend on that account and its permissions.

Version history

1
  1. v1.0.1LatestSep 16, 2026

Score

85% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 daysRequired25 pts
  • Auth declaredRequired10 pts
  • Tools listed15 pts

    Answer tools/list without a credential, or ship a package that starts in a sandbox without one.

  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts