When querying Bookings or Events via the API, two ID fields are returned in the response object:
id: A system-generated, globally unique identifier across all of Event Temple. Use this as the primary unique ID in API integrations.unique_id: The organizational ID displayed as the BK number (or EV number for Events) within the Event Temple UI. This ID is only unique within your organization and may be repeated across different organizations.
For complete schema details, view the Event Temple Developer's Hub.