A new RSVP can arrive in AddCal while an organiser is still preparing the event details. Without an automatic response, the attendee may not know whether their place has been recorded or what to do next. A Zap can use AddCal's New RSVP trigger to send an SMS through Mobile Message, giving the attendee a prompt confirmation.

The text can include the event name, arrival instruction, or a reminder to save the event link. Mobile Message can send SMS, send SMS to a list, create contact, update contact, or add contact to a list. An RSVP can therefore produce a direct attendee message, create a contact for later event communication, or place the person into a list chosen for that event. Use the fields AddCal provides when mapping the Zap.

The connection is through Zapier, rather than a native integration. Each workflow starts with one AddCal trigger and runs one Mobile Message action. It does not synchronise event records or attendee changes in both directions. Test the RSVP flow with a sample attendee so the event details and phone number appear as intended in the SMS.