RSVP

RSVP is a self-hosted event RSVP service built API-first. The public RSVP page and the organizer dashboard are both ordinary clients of the same API that any other integration would use. Neither has special access to the database, and if a page needs something the API can’t express, the API is what changes.

What it handles

• Capacity and waitlists that count guests, not responses, so a party of four takes four seats. Two people accepting the last seat at the same moment can’t oversell the event.
• Reminders, calendar invites, and add-to-calendar links, with video-call links and time zones handled for you.
• Recurring series, custom questions, party sizes, walk-ins, and attendance, plus CSV export.
• Guest self-service. Guests can change their answer from a signed link in their email, with no account needed.
• An MCP endpoint, so an agent can create events and read responses conversationally with the same permissions an organizer has.