Optionaldefault?: unknownDefault value. JSON/object fields may have {}; array fields may have [].
Optionaldescription?: stringOptionalreadOnly?: booleanOptionalresource?: string | nullPresent on entry/entries/asset/assets fields — the linked model or asset group.
Optionalitems?: {Present on array-typed fields (entries, assets). Describes the element schema.
Schema may carry extra metadata (multipleOf, format, validators, etc.).