# BackingData An interface for providing in-memory storage for a persistent model. ``` protocol BackingData ``` ## Topics ### Associated Types [`associatedtype Model : PersistentModel`](/documentation/SwiftData/BackingData/Model) ### Initializers [`init(for: Self.Model.Type)`](/documentation/SwiftData/BackingData/init(for:)) ### Instance Properties [`var metadata: Any`](/documentation/SwiftData/BackingData/metadata) [`var persistentModelID: PersistentIdentifier?`](/documentation/SwiftData/BackingData/persistentModelID) ### Instance Methods [`func getTransformableValue(forKey: KeyPath) -> Value`](/documentation/SwiftData/BackingData/getTransformableValue(forKey:)) [`func getValue(forKey: KeyPath) -> Value`](/documentation/SwiftData/BackingData/getValue(forKey:)-1pric) [`func getValue(forKey: KeyPath) -> Value`](/documentation/SwiftData/BackingData/getValue(forKey:)-209t6) [`func getValue(forKey: KeyPath) -> Value`](/documentation/SwiftData/BackingData/getValue(forKey:)-5fis7) [`func getValue(forKey: KeyPath) -> Value?`](/documentation/SwiftData/BackingData/getValue(forKey:)-5fo8) [`func getValue(forKey: KeyPath) -> Value`](/documentation/SwiftData/BackingData/getValue(forKey:)-8xj5n) [`func setTransformableValue(forKey: KeyPath, to: Value)`](/documentation/SwiftData/BackingData/setTransformableValue(forKey:to:)) [`func setValue(forKey: KeyPath, to: Value)`](/documentation/SwiftData/BackingData/setValue(forKey:to:)-1mr4x) [`func setValue(forKey: KeyPath, to: Value)`](/documentation/SwiftData/BackingData/setValue(forKey:to:)-2idfg) [`func setValue(forKey: KeyPath, to: Value)`](/documentation/SwiftData/BackingData/setValue(forKey:to:)-4d7yr) [`func setValue(forKey: KeyPath, to: Value)`](/documentation/SwiftData/BackingData/setValue(forKey:to:)-992es) [`func setValue(forKey: KeyPath, to: Value?)`](/documentation/SwiftData/BackingData/setValue(forKey:to:)-rzi4) --- 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)