List the guests of one stay, with the same fields as guests[] in Query Reservations. Use id as guest_id for Update Guest; every guest listed here can be updated there.

For a stay that is one room of a multi-room reservation, this also returns guests linked only to that room, which Query Reservations does not show. The same person can then appear twice with different ids (one copy linked to the whole reservation and one to the room). Query Reservations only shows the reservation-level copy, so update that copy if you read guests back through Query Reservations.

Guests are ordered with the booker first. id_number is personal data; store and display it accordingly. Returns 404 when the stay does not exist.