# HistoryUpdate ``` protocol HistoryUpdate : Sendable ``` ## Topics ### Associated Types [`associatedtype ChangeIdentifier : Comparable, Hashable, Sendable`](/documentation/SwiftData/HistoryUpdate/ChangeIdentifier-swift.associatedtype) [`associatedtype Model : PersistentModel`](/documentation/SwiftData/HistoryUpdate/Model) [`associatedtype TransactionIdentifier : Comparable, Hashable, Sendable`](/documentation/SwiftData/HistoryUpdate/TransactionIdentifier-swift.associatedtype) ### Instance Properties [`var changeIdentifier: Self.ChangeIdentifier`](/documentation/SwiftData/HistoryUpdate/changeIdentifier-swift.property) [`var changedPersistentIdentifier: PersistentIdentifier`](/documentation/SwiftData/HistoryUpdate/changedPersistentIdentifier) [`var transactionIdentifier: Self.TransactionIdentifier`](/documentation/SwiftData/HistoryUpdate/transactionIdentifier-swift.property) [`var updatedAttributes: [any PartialKeyPath & Sendable]`](/documentation/SwiftData/HistoryUpdate/updatedAttributes) ### Type Aliases [`typealias PropertyUpdate`](/documentation/SwiftData/HistoryUpdate/PropertyUpdate) ## Relationships ### Conforming Types [`DefaultHistoryUpdate`](/documentation/SwiftData/DefaultHistoryUpdate) ### Inherits From [`SendableMetatype`](/documentation/Swift/SendableMetatype) [`Sendable`](/documentation/Swift/Sendable) --- 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)