# NSApplicationDelegateAdaptor A property wrapper type that you use to create an AppKit app delegate. ``` @MainActor @preconcurrency @propertyWrapper struct NSApplicationDelegateAdaptor where DelegateType : NSObject, DelegateType : NSApplicationDelegate ``` ## Overview To handle app delegate callbacks in an app that uses the SwiftUI life cycle, define a type that conforms to the protocol, and implement the delegate methods that you need. For example, you can implement the method to handle remote notification registration: ``` class MyAppDelegate: NSObject, NSApplicationDelegate, ObservableObject { func application( _ application: NSApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data ) { // Record the device token. } } ``` Then use the `NSApplicationDelegateAdaptor` property wrapper inside your [`App`](/documentation/SwiftUI/App) declaration to tell SwiftUI about the delegate type: ``` @main struct MyApp: App { @NSApplicationDelegateAdaptor private var appDelegate: MyAppDelegate var body: some Scene { ... } } ``` SwiftUI instantiates the delegate and calls the delegate’s methods in response to life cycle events. Define the delegate adaptor only in your [`App`](/documentation/SwiftUI/App) declaration, and only once for a given app. If you declare it more than once, SwiftUI generates a runtime error. If your app delegate conforms to the protocol, as in the example above, then SwiftUI puts the delegate it creates into the [`Environment`](/documentation/SwiftUI/Environment). You can access the delegate from any scene or view in your app using the [`EnvironmentObject`](/documentation/SwiftUI/EnvironmentObject) property wrapper: ``` @EnvironmentObject private var appDelegate: MyAppDelegate ``` This enables you to use the dollar sign (`$`) prefix to get a binding to published properties that you declare in the delegate. For more information, see [`projectedValue`](/documentation/SwiftUI/NSApplicationDelegateAdaptor/projectedValue). > Important: Manage an app’s life cycle events without using an app > delegate whenever possible. For example, prefer to handle changes > in ``doc://com.apple.SwiftUI/documentation/SwiftUI/ScenePhase`` instead of relying on delegate callbacks, like > . ## Topics ### Creating a delegate adaptor [`init(_:)`](/documentation/SwiftUI/NSApplicationDelegateAdaptor/init(_:)) Creates an AppKit app delegate adaptor using an observable delegate. ### Getting the delegate adaptor [`projectedValue`](/documentation/SwiftUI/NSApplicationDelegateAdaptor/projectedValue) A projection of the observed object that provides bindings to its properties. [`wrappedValue`](/documentation/SwiftUI/NSApplicationDelegateAdaptor/wrappedValue) The underlying delegate. --- 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)