Flight booking API

The flight booking API reserves a revalidated itinerary and holds it until a ticketing deadline.

POST/Air/AirBook

Access requires the permission air_book

Book after you revalidate. Send the passengers and a lead contact. The response gives you a UniqueId and a TktTimeLimit. Nothing is ticketed yet. The seat is held until the deadline, so issue the ticket before then.

Path parameters

None.

Query parameters

None.

Body parameters

Name Type Required Default Description

SessionId string Yes - Your session id.

FareSourceCode string Yes - The code returned by revalidate.

ClientUniqueId string No - Your own reference. Later usable in booking data instead of UniqueId.

MarkupForAdult number No 0 Markup added per adult.

MarkupForChild number No 0 Markup added per child.

MarkupForInfant number No 0 Markup added per infant.

TravelerInfo object, required

Name	Type	Required	Description
`PhoneNumber`	string	Yes	Lead contact phone.
`Email`	string	Yes	Lead contact email.
`AirTravelers`	array of object	Yes	One entry per passenger. Minimum 1. The count must match the search pax mix.

AirTravelers[] object

Name	Type	Required	Description
`PassengerType`	integer	Yes	Passenger type code, for example `1` for an adult.
`Gender`	integer	Yes	`0` Male, `1` Female.
`DateOfBirth`	string	Yes	Date of birth, `YYYY-MM-DD`.
`PassengerName.PassengerFirstName`	string	Yes	Given name as on the passport.
`PassengerName.PassengerLastName`	string	Yes	Surname as on the passport.

Request

curl -X POST https://api.hermeseus.com/api/Air/AirBook \
  -H "Content-Type: application/json" \
  -d '{
    "SessionId": "8f3c81d2-4a5b-4c6d-9e0f-1a2b3c4d5e6f",
    "FareSourceCode": "dHA6ODc0NTE6ZmwxMjM0OjMyNw==",
    "ClientUniqueId": "order-0001",
    "TravelerInfo": {
      "PhoneNumber": "+441234567890",
      "Email": "traveller@example.com",
      "AirTravelers": [
        {
          "PassengerType": 1,
          "Gender": 0,
          "DateOfBirth": "1990-05-14",
          "PassengerName": {
            "PassengerFirstName": "Jane",
            "PassengerLastName": "Doe"
          }
        }
      ]
    }
  }'

const res = await fetch("https://api.hermeseus.com/api/Air/AirBook", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    SessionId: "8f3c81d2-4a5b-4c6d-9e0f-1a2b3c4d5e6f",
    FareSourceCode: "dHA6ODc0NTE6ZmwxMjM0OjMyNw==",
    ClientUniqueId: "order-0001",
    TravelerInfo: {
      PhoneNumber: "+441234567890",
      Email: "traveller@example.com",
      AirTravelers: [
        {
          PassengerType: 1,
          Gender: 0,
          DateOfBirth: "1990-05-14",
          PassengerName: { PassengerFirstName: "Jane", PassengerLastName: "Doe" }
        }
      ]
    }
  })
});

const data = await res.json();

import requests

res = requests.post(
    "https://api.hermeseus.com/api/Air/AirBook",
    json={
        "SessionId": "8f3c81d2-4a5b-4c6d-9e0f-1a2b3c4d5e6f",
        "FareSourceCode": "dHA6ODc0NTE6ZmwxMjM0OjMyNw==",
        "ClientUniqueId": "order-0001",
        "TravelerInfo": {
            "PhoneNumber": "+441234567890",
            "Email": "traveller@example.com",
            "AirTravelers": [
                {
                    "PassengerType": 1,
                    "Gender": 0,
                    "DateOfBirth": "1990-05-14",
                    "PassengerName": {
                        "PassengerFirstName": "Jane",
                        "PassengerLastName": "Doe",
                    },
                }
            ],
        },
    },
)

data = res.json()

Response

Field	Type	Description
`Success`	boolean	`true` on success.
`UniqueId`	string	The booking id. Carry it into ticketing, tracking, and cancellation.
`TktTimeLimit`	string	Deadline to issue the ticket. Issue before this time or the hold is released.
`TktTimeLimitTimeZone`	string	Timezone of `TktTimeLimit`.
`Category`	integer	`10`. Booked, awaiting ticketing.
`Status`	integer	`10`. Booked, awaiting ticketing.
`PriceChange`	boolean	`true` if the fare changed during booking.
`WarningMessage`	string	Any non-fatal warning, otherwise `null`.
`Error`	object	`null` on success.

{
  "Success": true,
  "UniqueId": "TP-2026-000512",
  "TktTimeLimit": "2026-10-10T18:00:00",
  "TktTimeLimitTimeZone": "UTC",
  "Category": 10,
  "Status": 10,
  "PriceChange": false,
  "WarningMessage": null,
  "Error": null
}

A booking is not a ticket. Status 10 holds a seat. Issue the ticket with AirOrderTicket before TktTimeLimit, otherwise the reservation is released.

Errors

Code	Meaning	Fix
`Err0106001`	A required traveller field is missing or invalid.	Fix the field named in the message.
`Err0102003`	The fare is no longer available.	Search and revalidate again.
`Err0102005`	The fare has expired.	Search and revalidate again.