After POST /v1/stays/bookings/{bookingId}/confirm answered 410 OFFER_EXPIRED, ask the provider for one replacement rate at the same property and move the booking onto it. close_match keeps the board and does not lose free cancellation, but its price can change: when priceChanged is true, show newTotal before the traveller confirms it with the same confirm call. other_rate also moves the booking but should not be confirmed without the traveller choosing again; free cancellation whose deadline has already passed counts as lost. no_rate means no replacement could be booked. 409 BOOKING_CONFLICT means the booking is no longer awaiting confirmation; read the booking again instead of starting a new search.

Idempotency-Key is required. Replaying a key for the same booking returns the original answer without asking the provider again; a new key asks again.