Real-time booking modification notification

When a booking is modified on the Holidu side, such as a change to dates, guest count, or payment schedule, Holidu can push an instant notification to your endpoint, eliminating the need to poll the GET booking details endpoint for updates.

This feature is active for Holidu Payments bookings only. Holidu POSTs a payload to your endpoint and you respond with ACKNOWLEDGED.

To enable this feature, provide your modification endpoint URL to Holidu. We will configure it on our side.

Request

Holidu sends an HTTP POST to your configured modification endpoint with the following JSON body:

Parameter	Type	Required	Description
`holiduBookingId`	Long	Yes	Holidu's internal booking ID
`providerBookingId`	String	Yes	Your reference for the booking (the `externalId` you returned at booking creation)
`action`	String	Yes	Always `"MODIFICATION"`
`paymentHandler`	String	Yes	Always `"HOLIDU"`
`checkin`	LocalDate `YYYY-MM-DD`	Yes	Updated check-in date
`checkout`	LocalDate `YYYY-MM-DD`	Yes	Updated check-out date
`adults`	Integer	Yes	Total number of adult guests
`children`	Integer	Yes	Total number of child guests
`paymentRates`	Array of objects	Yes	Updated payment schedule
`paymentRates[].amount`	Number	Yes	Installment amount
`paymentRates[].currency`	String	Yes	ISO 4217 currency code (e.g. `"EUR"`)
`paymentRates[].dueDate`	LocalDate `YYYY-MM-DD`	Yes	Date the installment is due

Example

{
  "holiduBookingId": 123123123,
  "providerBookingId": "your-booking-ref-001",
  "action": "MODIFICATION",
  "paymentHandler": "HOLIDU",
  "checkin": "2025-03-10",
  "checkout": "2025-03-15",
  "adults": 2,
  "children": 1,
  "paymentRates": [
    {
      "amount": 500,
      "currency": "EUR",
      "dueDate": "2025-03-01"
    }
  ]
}

Response

Your endpoint must respond with HTTP 200 and the following JSON body:

Parameter	Type	Required	Description
`status`	String	Yes	Must be `"ACKNOWLEDGED"`

Example

{
  "status": "ACKNOWLEDGED"
}

Retry and fallback behaviour

Scenario	Behaviour
HTTP `5xx` from your endpoint	Holidu retries up to 3 times with exponential back-off (starting at 5 seconds)
HTTP `4xx` from your endpoint	No retry. Treated as a permanent failure
All retries exhausted / permanent failure	Holidu falls back to sending a modification email notification