| date | No | YYYY-MM-DD, Sint Maarten | |
| time | No | HH:MM, Sint Maarten (UTC−4) | |
| notes | No | e.g. pressure preference, allergies, occasion | |
| guests | No | Couples treatments are always 2 | |
| language | No | Language of the pay page and email | |
| service_id | Yes | An id from list_services | |
| start_time | No | ISO 8601 with offset, e.g. 2026-11-20T15:00:00-04:00. Or give date and time. | |
| customer_name | Yes | | |
| customer_email | No | If given, the guest also gets the pay link by email | |
| customer_phone | No | E.164, e.g. +17215551234 | |
| idempotency_key | No | Repeating a request with the same key within 24 hours returns the same booking | |
| customer_consent | Yes | Must be true: the guest asked for this booking and agrees to be contacted about it | |