# NSFileProviderExtension The principal class for the nonreplicated File Provider extension. ``` class NSFileProviderExtension ``` ## Overview To create a nonreplicated File Provider extension, start by creating a subclass of the [`NSFileProviderExtension`](/documentation/FileProvider/NSFileProviderExtension) class. When implementing your [`NSFileProviderExtension`](/documentation/FileProvider/NSFileProviderExtension) subclass, remember: - Override all of the extension’s methods (except the deprecated methods), even if your implementation is only an empty method. - Use your method implementations to provide access to the documents and folders managed by your file provider. - Don’t call `super` in your method implementations. Don’t use the [`NSFileProviderExtension`](/documentation/FileProvider/NSFileProviderExtension) class in macOS. Instead, create an subclass that adopts the [`NSFileProviderReplicatedExtension`](/documentation/FileProvider/NSFileProviderReplicatedExtension) and [`NSFileProviderEnumerating`](/documentation/FileProvider/NSFileProviderEnumerating) protocols. For more information, see [Replicated File Provider extension](/documentation/FileProvider/replicated-file-provider-extension). ## Topics ### Working with items and persistent identifiers [`persistentIdentifierForItem(at:)`](/documentation/FileProvider/NSFileProviderExtension/persistentIdentifierForItem(at:)) Returns a unique identifier for the given URL. [`urlForItem(withPersistentIdentifier:)`](/documentation/FileProvider/NSFileProviderExtension/urlForItem(withPersistentIdentifier:)) Returns the URL for a given persistent identifier. [`item(for:)`](/documentation/FileProvider/NSFileProviderExtension/item(for:)) Returns a description of the item associated with the persistent identifier. [`enumerator(for:)`](/documentation/FileProvider/NSFileProviderExtension/enumerator(for:)) Returns an enumerator for the specified item. [`NSFileProviderItemIdentifier`](/documentation/FileProvider/NSFileProviderItemIdentifier) A unique identifier for an item managed by the File Provider extension. ### Managing shared files [`itemChanged(at:)`](/documentation/FileProvider/NSFileProviderExtension/itemChanged(at:)) Tells the File Provider extension that a document has changed. [`providePlaceholder(at:completionHandler:)`](/documentation/FileProvider/NSFileProviderExtension/providePlaceholder(at:completionHandler:)) Triggers the creation of a placeholder for the given URL. [`startProvidingItem(at:completionHandler:)`](/documentation/FileProvider/NSFileProviderExtension/startProvidingItem(at:completionHandler:)) Provides an actual file on disk for a placeholder. [`stopProvidingItem(at:)`](/documentation/FileProvider/NSFileProviderExtension/stopProvidingItem(at:)) Tells the File Provider extension that a given document is no longer being accessed. ### Handling actions [Providing support for user-driven actions](/documentation/FileProvider/providing-support-for-user-driven-actions) Override methods to handle user-initiated actions. [`createDirectory(withName:inParentItemIdentifier:completionHandler:)`](/documentation/FileProvider/NSFileProviderExtension/createDirectory(withName:inParentItemIdentifier:completionHandler:)) Creates a directory with the given name inside the given parent directory. [`deleteItem(withIdentifier:completionHandler:)`](/documentation/FileProvider/NSFileProviderExtension/deleteItem(withIdentifier:completionHandler:)) Permanently deletes an item from the trash. [`importDocument(at:toParentItemIdentifier:completionHandler:)`](/documentation/FileProvider/NSFileProviderExtension/importDocument(at:toParentItemIdentifier:completionHandler:)) Imports a file or package into the given parent directory. [`renameItem(withIdentifier:toName:completionHandler:)`](/documentation/FileProvider/NSFileProviderExtension/renameItem(withIdentifier:toName:completionHandler:)) Renames a document or directory. [`reparentItem(withIdentifier:toParentItemWithIdentifier:newName:completionHandler:)`](/documentation/FileProvider/NSFileProviderExtension/reparentItem(withIdentifier:toParentItemWithIdentifier:newName:completionHandler:)) Moves the specified item into the given parent directory. [`setFavoriteRank(_:forItemIdentifier:completionHandler:)`](/documentation/FileProvider/NSFileProviderExtension/setFavoriteRank(_:forItemIdentifier:completionHandler:)) Marks a directory as a favorite and sets its relative order in the Favorites list. [`setLastUsedDate(_:forItemIdentifier:completionHandler:)`](/documentation/FileProvider/NSFileProviderExtension/setLastUsedDate(_:forItemIdentifier:completionHandler:)) Marks an item as recently used and sets its relative order in the Recents list. [`setTagData(_:forItemIdentifier:completionHandler:)`](/documentation/FileProvider/NSFileProviderExtension/setTagData(_:forItemIdentifier:completionHandler:)) Tags an item. [`trashItem(withIdentifier:completionHandler:)`](/documentation/FileProvider/NSFileProviderExtension/trashItem(withIdentifier:completionHandler:)) Moves an item into the trash. [`untrashItem(withIdentifier:toParentItemIdentifier:completionHandler:)`](/documentation/FileProvider/NSFileProviderExtension/untrashItem(withIdentifier:toParentItemIdentifier:completionHandler:)) Moves an item out of the trash. ### Managing domains [`domain`](/documentation/FileProvider/NSFileProviderExtension/domain) The domain managed by this file provider object. ### Accessing thumbnails [`fetchThumbnails(for:requestedSize:perThumbnailCompletionHandler:completionHandler:)`](/documentation/FileProvider/NSFileProviderExtension/fetchThumbnails(for:requestedSize:perThumbnailCompletionHandler:completionHandler:)) Fetches the thumbnails for items that have been enumerated by the file provider. ### Working with services [`supportedServiceSources(for:)`](/documentation/FileProvider/NSFileProviderExtension/supportedServiceSources(for:)) Return an array of service sources that let the host app perform actions associated with the specified item. [`NSFileProviderServiceSource`](/documentation/FileProvider/NSFileProviderServiceSource) A service that provides a custom communication channel between the host app and the File Provider extension. ### Managing placeholders These methods have been deprecated and moved to the [`NSFileProviderManager`](/documentation/FileProvider/NSFileProviderManager) A manager object that you use to communicate with the file provider from either your app or your File Provider extension. class. [`placeholderURL(for:)`](/documentation/FileProvider/NSFileProviderExtension/placeholderURL(for:)) Returns a placeholder URL for a given document URL. [`writePlaceholder(at:withMetadata:)`](/documentation/FileProvider/NSFileProviderExtension/writePlaceholder(at:withMetadata:)) Writes a document placeholder with the provided metadata. ### Accessing the document storage These methods have been deprecated and moved to the [`NSFileProviderManager`](/documentation/FileProvider/NSFileProviderManager) A manager object that you use to communicate with the file provider from either your app or your File Provider extension. class. [`documentStorageURL`](/documentation/FileProvider/NSFileProviderExtension/documentStorageURL) The root URL for all shared documents. [`providerIdentifier`](/documentation/FileProvider/NSFileProviderExtension/providerIdentifier) A purpose identifier for coordinated reads and writes. --- 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)