Cal.com and WhatsApp: automatic reminders for every booking
Connect Cal.com: every booking lands in the Agenda in real time, with WhatsApp/SMS/email reminders before the meeting and moves and cancellations handled for you.
What you get by connecting Cal.com
Every booking lands in the SendApp Agenda, with nothing to enter by hand.
Messages go out on their own before and after the appointment or the stay, following the rules you set.
The customer joins your contacts: you can write to them again after the appointment.
How to connect Cal.com to SendApp
Steps taken from the official SendApp guide, read on 19 September 2026.
How it works
SendApp connects to your Cal.com account and registers a webhook: every new booking, move or cancellation reaches the Agenda at once. A timed read acts as a safety net. Customers land in your contacts and reminders follow the rules you set.
Connecting
- 1Open Apps > Cal.com and press Sign in with Cal.com.
- 2On Cal.com, allow SendApp to read your bookings and event types: you are back in SendApp straight away and the Agenda fills up.
- 3Alternatively open Advanced and paste an API key created in Cal.com under Settings > Developer > API keys. This is also the way for a self-hosted Cal.com: type the address of its API.
Ask for the phone number
WhatsApp and SMS reminders need the customer's phone: add a phone question to the event type in Cal.com. The app page tells you how many upcoming appointments have none.
Reminders
- 1Add up to five rules: how long before the appointment, the channel and the message.
- 2Send yourself a test before switching them on.
Settings
Choose how many days ahead to import, which event types, the contact tag, and whether to import past appointments too (off by default).
Check
The app page lists the upcoming appointments with their planned reminders and the sync history.
An example message
Hi Julia, a reminder of your appointment tomorrow at 3pm. If something comes up, reply here and we will move it.
Illustrative example: you write the text.
More integrations in the same family
Frequently asked questions
Connect Cal.com to SendApp today
Connect Cal.com: every booking lands in the Agenda in real time, with WhatsApp/SMS/email reminders before the meeting and moves and cancellations handled for you.