---
title: category
framework: appintents
role: symbol
role_heading: Instance Property
path: appintents/appschema/mailenum/category
---

# category

An enum schema for a category parameter.

## Declaration

```swift
var category: some AppSchemaEnum { get }
```

## Discussion

Discussion To make your app’s parameter types available to Apple Intelligence, conform your AppEnum to a schema that describes a parameter’s possible values to the system. If your app’s functionality aligns with the mail domain and a parameter type matches the category schema, you can generate the protocol conformance the schema requires for your app enum implementation with the @AppEnum( .mail.category) Swift macro. To make your app work with Siri, see Apple Intelligence and Siri AI. The following example shows an app enum that conforms to the category schema: @AppEnum(schema: .mail.category) enum MailCategory: String {     case <#MailCategory Case#>

static let caseDisplayRepresentations: [Self: DisplayRepresentation] = [         <#DisplayRepresentations#>     ] } The schema supports the following system experiences: Siri Shortcuts For more information about the App Intents framework and the experiences it supports, see Getting started with the App Intents framework.