# AccessoryDataProvider A protocol for an extension that receives iOS system notifications and curates their data for your accessory. ``` protocol AccessoryDataProvider : AppExtension, Sendable where Self.Configuration : AccessoryDataProviderConfiguration ``` ## Overview Implement this protocol in an extension with an `EXExtensionPointIdentifier` value of `com.apple.accessory-data-provider` to receive notification data for eventual forwarding to an accessory that you develop. The extension runs in a sandboxed environment and communicates with the system through the extension’s configuration object ([`AccessoryDataProviderConfiguration`](/documentation/AccessoryTransportExtension/AccessoryDataProviderConfiguration)). > Important: The system requires your app extension to have the entitlement to use this protocol. ## Add the necessary target configuration In your extension’s target properties, include the `EXCapabilities` key with the value `AccessoryNotifications.NotificationsForwarding`: ```xml EXAppExtensionAttributes EXExtensionPointIdentifier com.apple.accessory-data-provider EXCapabilities AccessoryNotifications.NotificationsForwarding ``` ## Implement the extension point In your extension’s Swift code, implement the protocol and declare the capability with your implementation: ```swift struct DataProvider: AccessoryDataProvider { var extensionPoint: AppExtensionPoint { Identifier("com.apple.accessory-data-provider") Implementing { NotificationsForwarding { MyNotificationsHandler() } } } } class MyNotificationsHandler: AccessoryNotificationsHandler { // Your extension's implementation. } ``` ## Share data between the app and the extension Configure a shared app group so your companion app can provide information to the extension. The extension has read-only access to the shared container. Use the shared container to store: - Authentication tokens for your private servers - Accessory-specific preferences (max payload size, content filtering) - Device-specific configuration ```swift // In the companion app, write to the shared container. let sharedDefaults = UserDefaults(suiteName: "group.com.yourcompany.accessoryapp") sharedDefaults?.set(authToken, forKey: "ServerAuthToken") // In the extension, read from the shared container. let sharedDefaults = UserDefaults(suiteName: "group.com.yourcompany.accessoryapp") let authToken = sharedDefaults?.string(forKey: "ServerAuthToken") ``` For more information, see [Receiving iOS notifications on an accessory](/documentation/AccessoryTransportExtension/receiving-ios-notifications-on-an-accessory). ## Relationships ### Inherits From [`SendableMetatype`](/documentation/Swift/SendableMetatype) [`Sendable`](/documentation/Swift/Sendable) [`AppExtension`](/documentation/ExtensionFoundation/AppExtension) --- 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)