What is Book Calendar Slots?
The Book Calendar Slots function allows your Voice AI agent to schedule appointments directly into your Cal.com calendar during live conversations. After a caller selects a time slot, your agent can book it instantly.
Configuration Options
| Setting | Description |
|---|---|
| Description (Prompt) | When to book - e.g., “Use this tool to book an appointment with given details and save the appointment in the calendar” |
| Pre-tool Message | What agent says while booking - e.g., “Just give me a moment, I’ll be back with you” |
| API Key | Your Cal.com API key |
| Select Events | Choose event types from your Cal.com account (15 min, 30 min, etc.) |
| Choose Timezone | Timezone for accurate slot booking |
Select Events and Choose Timezone dropdowns appear only after entering a valid Cal.com API key.
How to Set Up
Open Tools Tab
Navigate to Tools Tab in your agent configuration.
Select Event Type
Choose which event to book - 15 min meeting, 30 min meeting, or your custom events.
Write Description
Add a clear trigger description - e.g., “Book the appointment after the caller confirms their preferred time slot.”
Example Conversation
Caller confirms appointment time
Caller confirms appointment time
Caller: “I’ll take the 2 PM slot on Friday.”Agent: “Perfect! Let me book that for you. Just give me a moment…”Agent triggers book_appointment functionAgent: “Done! I’ve booked your appointment for Friday at 2 PM. You’ll receive a calendar invite shortly. Is there anything else I can help with?”
Best Practices
Use with Check Slots
Combine with Check Calendar Slots - first fetch availability, then book
Match Timezones
Ensure Bolna timezone matches Cal.com event timezone
Confirm Before Booking
Have your agent confirm the slot with the caller before booking
Collect Required Info
Ensure agent collects name and email before triggering the booking