The fares to show at once for a flight, before the airline's own answer.

GET /flight-booking/options costs one supplier lookup (10 to 18 seconds cold, Nov 2026). The fare step asks this beside it and shows the answer while that lookup runs: the stored flight's price on the airline's lowest fare by name (options, one fare), and the airline's other usual fares by name with no price yet (pending_fares). No supplier work.

options is empty when there is nothing to show at once, and the fare step then waits for the live answer as it always has: the live list is already cached, the trip is not one airline in economy with a ladder we hold, the party changed since the search, or a fare hold or limited-time offer prices this viewer's ladder (their held price must not be preceded by another one).

The fare here is not a booking option until the live answer confirms it: the client creates the session on the confirmed fare, never on this one.