{
  "externalId": "booking-demo-001",
  "customerName": "Alex Example",
  "phone": "+15555550123",
  "startsAt": "2026-10-13T10:00:00+02:00",
  "timezone": "Europe/Brussels",
  "smsConsent": true,
  "sourceUpdatedAt": "2026-10-12T11:00:00+02:00",
  "action": "upsert"
}