This is the basic shopping flow with seat selection. We have provided the inputs and outputs for each API at each stage of the sequence.
Both AirShopping and OfferPrice APIs return below fare rules per passenger type for each offer:
Fare Rule type
Fare Condition
Eligibility
Penalty Amount
Change
Before departure
Allowed or not allowed
Penalty amount, if applicable
Change
After departure
Allowed or not allowed
Penalty amount, if applicable
Cancel
Before departure
Allowed or not allowed
Penalty amount, if applicable
Cancel
After departure
Allowed or not allowed
Penalty amount, if applicable
*Based on the flexibility of the fare, it is possible to change or cancel the itinerary.
If the fare is restrictive, then change or cancel is not allowed. In those case the entire fare (what is paid) gets forfeited.
In case it is flexible, then change or cancel is allowed, without any penalty or additional charges.
The eligibility tells us, if the change/cancel is allowed or not. If allowed, then this could be either with some charges or completely free to change (that is implied by the Penalty Charge column).