How do I create a book on calendar tool for an AI agent?

Last updated: November 5, 2026

A book on calendar tool lets an AI agent create Cal.com bookings during a conversation or call. The tool must be configured, selected for the agent, and described clearly in the agent instructions.

Before you start

  • Make sure your Cal.com API key is available or already configured for your organization.

  • Find the Cal.com event type ID for the meeting type the agent should book.

  • Decide the timezone the booking tool should use.

  • Consider pairing this with a check calendar availability tool so the agent confirms open times before booking.

Steps

  1. Open Agents.

  2. Click Tools.

  3. Select Create tool.

  4. Choose Book on calendar (Cal.com).

  5. Enter a tool name and optional description.

  6. Click Save.

  7. Confirm or update the tool label and description.

  8. Confirm the Cal.com API key is populated.

  9. Enter the Cal.com event type ID.

  10. Set the timezone using a format like America/Los_Angeles.

  11. Save the tool.

  12. Open the agent that should use the tool.

  13. Add the tool in Select tools.

  14. In the agent instructions, tell the agent when it is allowed to book and what confirmation it must collect first.

  15. Save the agent.

Tips

  • Require explicit customer confirmation before booking.

  • Check availability before creating the booking.

  • Use the correct timezone to prevent scheduling errors.

  • Describe what information the agent must collect, such as name, email, and desired time.

Troubleshooting

  • Booking fails: Verify the Cal.com event type ID.

  • The tool cannot create bookings: Confirm the Cal.com API key is valid.

  • The booking time is incorrect: Update the timezone setting.

  • The agent does not book: Confirm the tool is selected and referenced in the agent instructions.