### Answer ## Booking New Appointments To book new appointments with Retell AI, you can use the built-in Cal.com integration: [(1) ]() 1. Create an AI agent tailored for appointment booking 2. Add the "Check Availability" and "Book Appointments" functions to your agent 3. Connect to a Cal.com account by entering the necessary credentials and event ID 4. Configure time zone settings on both the Cal.com platform and the Retell AI dashboard 5. Define scenarios in your prompts where the booking functions will be triggered Example tool configuration:

json
{
  "type": "book_appointment_cal",
  "name": "book_appointment",
  "description": "Book an annual check up.",
  "cal_api_key": "cal_live_xxxxxxxxxxxx",
  "event_type_id": 60444,
  "timezone": "America/Los_Angeles"
}

[(2) ]() ## Rescheduling Appointments The built-in Retell integration with Cal.com is **limited to scheduling and checking availability**—it does not natively support rescheduling or cancellation. [(3) ]() To reschedule appointments, you have two options: 1. Use the Cal.com API directly — Cal.com's API does support rescheduling: ` 2. Build a custom function — You would need to: - Get all bookings first using the Cal.com API - Find the specific booking (by email or phone number) - Use the booking ID to reschedule via the Cal.com reschedule endpoint [(4) ]() Rescheduling essentially involves canceling the original appointment and then booking a new one. Some community members have integrated this workflow using automation tools like Make.com or n8n to handle the rescheduling logic. [(3) ]()

​ To learn more, see the sources I considered: [[1] AI Appointment Scheduling with Voice AI Booking Assistant](https://www.retellai.com/features/book-appointments) [[2] Get Retell LLM](https://docs.retellai.com/api-references/get-retell-llm) [[3] Discord message from @fred_0515 on 2025-01-17](https://discord.com/channels/1186424376300679209/1294891368505937952/1329899365497569344) [[4] MASTER THE FUTURE OF VOICE AI - Never Miss Another Appointment]() ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.