# BADownloaderExtension An interface for reacting to app life-cycle events and processing concluded asset downloads while your app isn’t running. ``` protocol BADownloaderExtension : AppExtension ``` ## Topics ### Processing downloads [`func backgroundDownload(BADownload, didReceive: URLAuthenticationChallenge) async -> (URLSession.AuthChallengeDisposition, URLCredential?)`](/documentation/BackgroundAssets/BADownloaderExtension-qwaw/backgroundDownload(_:didReceive:)) [`func backgroundDownload(BADownload, finishedWithFileURL: URL)`](/documentation/BackgroundAssets/BADownloaderExtension-qwaw/backgroundDownload(_:finishedWithFileURL:)) [`func backgroundDownload(BADownload, failedWithError: any Error)`](/documentation/BackgroundAssets/BADownloaderExtension-qwaw/backgroundDownload(_:failedWithError:)) ### Checking for asset updates [`func downloads(for: BAContentRequest, manifestURL: URL, extensionInfo: BAAppExtensionInfo) -> Set`](/documentation/BackgroundAssets/BADownloaderExtension-qwaw/downloads(for:manifestURL:extensionInfo:)) [`enum BAContentRequest`](/documentation/BackgroundAssets/BAContentRequest) A type that indicates the purpose of a content download request. [`class BAAppExtensionInfo`](/documentation/BackgroundAssets/BAAppExtensionInfo) ### Reacting to extension events [`func extensionWillTerminate()`](/documentation/BackgroundAssets/BADownloaderExtension-qwaw/extensionWillTerminate()) This method may be called shortly before the extension is terminated. [`func extensionWillTerminate()`](/documentation/BackgroundAssets/BADownloaderExtension-qwaw/extensionWillTerminate()-236ac) ### Instance Methods [`func extensionWillTerminate()`](/documentation/BackgroundAssets/BADownloaderExtension-qwaw/extensionWillTerminate()) This method may be called shortly before the extension is terminated. ## Relationships ### Inherited By [`ManagedDownloaderExtension`](/documentation/BackgroundAssets/ManagedDownloaderExtension) ### Inherits From [`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)