How to Set Up Webhooks in Koalendar

Use webhooks to get real-time updates—POST requests are sent when someone schedules, reschedules, or cancels an appointment on your booking page.

This is useful if you're building custom automations using platforms like Zapier, Make (Integromat), n8n, or your own backend code.

Step 1: Create Your Webhook Endpoint

1. Open your Booking Page Editor
2. Scroll to the After Booking section
3. Enter your webhook URL endpoint (the destination for POST requests)

Step 2: Test & Automate

• Perform a test booking, reschedule, or cancel to trigger a webhook
• Inspect your server logs or webhook tool to confirm receipt of the POST
• Each payload includes:
  • Event type:
    • event.created    – when someone books an appointment
    • event.tentative    – when someone makes a tentative booking
    • event.rescheduled    – when an invitee changes the booking time
    • event.canceled    – when an invitee cancels their appointment
  • Booking details (name, email, location, start_at, end_at, etc.)
  • Invitee answers via invitee.fields    —with question IDs and values

You can use this to:

• Trigger emails or internal alerts
• Update your CRM or database
• Sync data across apps via Zapier or custom logic

Example payload

The invitee.fields contains the answers to the questions you ask on your booking form.

The key of the object is the question id, which you can find when editing a question (at the top):

🛠️ Webhook Not Received or Late?

• Right booking page: each booking page has its own webhook URL. Check that it's set on the page that received the booking, and that you saved the page.
• Full URL: enter the complete address, starting with https:// . An invalid URL is ignored.
• Respond quickly: your endpoint should accept a POST  with a JSON body and reply with a 2xx  status. If it times out or returns an error, Koalendar tries again later, so the webhook arrives late.
• Nothing blocking it: make sure no login, firewall or IP filter blocks requests to your endpoint.
• Test the delivery: paste a temporary URL from a tool like webhook.site, make a test booking, and check that the request arrives.

ℹ️ Frequently Asked Questions

What events trigger a webhook?

event.created  , event.tentative  , event.rescheduled  , and event.canceled   

Can I use Zapier with webhooks?

Yes! Webhooks can be used to trigger Zapier actions or any integration platform that accepts POST requests. Read our Zapier guide.

What happens if my webhook fails?

Koalendar will retry if your endpoint is temporarily unreachable or returns an error.

Can I update or remove my webhook later?

Yes. Just return to the webhook settings in your booking page editor.