# ContactProviderExtension The protocol your app extension implements, which provides contact items to the system-wide Contacts ecosystem. ``` protocol ContactProviderExtension : ContactItemEnumerating, AppExtension ``` ## Overview For the system to recognize your app extension, use the following identifier in the extension’s `Info.plist` file: ``` EXAppExtensionAttributes EXExtensionPointIdentifier com.apple.contact.provider.extension ``` Installing the host app installs your extension, but the system won’t run the extension until the extension domain is enabled. When the extension runs, the system first calls the extension’s [`configure(for:)`](/documentation/ContactProvider/ContactProviderExtension/configure(for:)) method. Then you set up the enumerator that provides contact items from your data store. The following shows a basic implementation of a `ContactProviderExtension`. Because `ContactProviderExtension` inherits from [`ContactItemEnumerating`](/documentation/ContactProvider/ContactItemEnumerating) the implementation also implements [`enumerator(for:)`](/documentation/ContactProvider/ContactItemEnumerating/enumerator(for:)) which returns a [`ContactItemEnumerator`](/documentation/ContactProvider/ContactItemEnumerator) on demand. In this example, the extension sets up a `RootContainerEnumerator` to provide its contact items; see the [`ContactItemEnumerator`](/documentation/ContactProvider/ContactItemEnumerator) discussion for details of how `RootContainerEnumerator` works. ```swift import ContactProvider @main class ExtensionExample: ContactProviderExtension { private let rootContainerEnumerator: RootContainerEnumerator required init() { rootContainerEnumerator = RootContainerEnumerator() } func configure(for domain: ContactProviderDomain) { rootContainerEnumerator.configure(for: domain) } func enumerator(for collection: ContactItem.Identifier) -> any ContactItemEnumerator { return rootContainerEnumerator } func invalidate() async { // Stop the enumeration and clean up, in preparation for the extension to terminate. } } ``` ## Topics ### Configuring an extension [`configure(for:)`](/documentation/ContactProvider/ContactProviderExtension/configure(for:)) Configures the extension instance for a domain. ### Managing the extension life cycle [`invalidate()`](/documentation/ContactProvider/ContactProviderExtension/invalidate()) Invalidates the extension. --- 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)