n8n WhatsApp Cloud API Appointment Reminder Webhook Workflow

Automated WhatsApp Appointment Reminders—Triggered by Webhooks

Send WhatsApp appointment reminders automatically with an n8n webhook workflow that notifies attendees 24 hours and 2 hours before their appointment start time using the WhatsApp Cloud API (Meta Graph API).

What this workflow does

• Receives appointment details via a POST webhook request, including:
  • attendeeName
  • attendeePhoneE164 (E.164 phone number)
  • startTime (appointment start timestamp)
  • whatsappPhoneNumberId (your WhatsApp sender ID)
• Normalizes the payload into structured customer and appointment fields used by the reminder messages.
• Waits until 24 hours before the appointment start time, then sends a WhatsApp text reminder through the Meta Graph API.
• Waits until 2 hours before the appointment start time, then sends a final WhatsApp text reminder via the Meta Graph API.

Use cases

• Clinics and dental practices sending no-hassle reminders for upcoming appointments.
• Consulting and coaching teams reducing missed sessions with timely WhatsApp nudges.
• SaaS appointment scheduling that posts data from Cal.com, Calendly, or a custom form into n8n to trigger reminders.

Technical details

• n8n nodes used: webhook, set, wait, http request, and a sticky note for workflow guidance.
• WhatsApp integration: uses the WhatsApp Cloud API (Meta Graph API) to send text messages.
• Authentication: configure an HTTP Header credential with Authorization: Bearer <TOKEN> and select it on both WhatsApp send requests.
• Required setup: create a Meta for Developers WhatsApp Cloud API app, then provide your WhatsApp Phone Number ID and permanent access token.
• Webhook integration: copy the workflow webhook URL and POST the required fields (attendeeName, attendeePhoneE164, startTime, whatsappPhoneNumberId) from your scheduling system.