Book Appointments with Voice Using VAPI & Cal.com

This template uses VAPI and Cal.com to book appointments through a voice conversation. It detects whether the user wants to check availability or book an appointment, then responds naturally with real-time scheduling options.

Who is this for? This workflow is perfect for:

Voice assistant developers

AI receptionists and smart concierge tools

Service providers (salons, clinics, coaches) needing hands-free scheduling

Anyone building voice-based customer experiences

What does it do? This workflow turns a natural voice conversation into a working appointment system.

It starts with a Webhook connected to your VAPI voice agent.

The Set node extracts user intent (like “check availability” or “book now”).

A Switch node branches logic based on the intent.

If the user wants to check availability, the workflow fetches available times from Cal.com.

If the user wants to book, it creates a new event using Cal.com's API.

The final result is sent back to VAPI as a conversational voice response.

How to use it Import this workflow into your n8n instance.

Set up a Webhook node and connect it to your VAPI voice agent.

Add your Cal.com API token as a credential (use HTTP Header Auth).

Deploy and test using VAPI’s simulator or real phone input.

(Optional) Customize the OpenAI prompt if you're using it to process or moderate inputs.

Requirements A working VAPI agent

A Cal.com account with API access

n8n (cloud or self-hosted)

An understanding of how to configure webhook and API credentials in n8n

Customization Ideas Swap out Cal.com with another booking API (like Calendly)

Add a Google Sheets or Supabase node to log appointments

Use OpenAI to summarize or sanitize voice inputs before proceeding

Build multi-turn conversations in VAPI for more complex bookings