# App enums Make your app’s enumerations and predefined values available to the system by using app enum types. ## Overview If your app intents or app entities expose variables with predefined values, support the [`AppEnum`](/documentation/AppIntents/AppEnum) protocol in those types. When an intent parameter or entity property conforms to this protocol, the system can suggest values readily in conversations. For example, consider a food ordering app that offers small, medium, and large beverages, and defines an intent that takes the beverage size as a parameter. If the person doesn’t specify a size when placing an order, but the parameter’s type supports the [`AppEnum`](/documentation/AppIntents/AppEnum) protocol, the system can prompt for one of the defined sizes automatically. If you can represent each value of an enumeration as a URL, also add support for the [`URLRepresentableEnum`](/documentation/AppIntents/URLRepresentableEnum) protocol. ## Topics ### Enumerated types [`AppEnum`](/documentation/AppIntents/AppEnum) An interface to express that a custom type has a predefined, static set of values. ### Universal link navigation [`URLRepresentableEnum`](/documentation/AppIntents/URLRepresentableEnum) An interface you apply to an app enum type so the system can handle it like a universal link. [`EnumURLRepresentation`](/documentation/AppIntents/EnumURLRepresentation) The type that provides the URL for an app enum. [`CustomURLRepresentationParameterConvertible`](/documentation/AppIntents/CustomURLRepresentationParameterConvertible) An interface that allows a type to express its contents in a URL representation. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)