Hi, I'm using SwiftData in my app, and I want to sent data to iCloud with CloudKit, but I found that If the user turns off my App iCloud sync function in the settings App, the local data will also be deleted. A better way is maintaining the local data, just don't connect to iCloud.How should I do that? I need guidance!!! I'm just getting started with CloudKit And I would be appreciated!

There's some logic in my app that first checks to see if a specific CloudKit record zone exists. If it doesn't, it creates the zone, and then my application continues on with its work. The way I've implemented this right now is by catching the zoneNotFound error when I call CKDatabase#recordZone(for:) (docs) and creating the zone when that happens: do { try await db.recordZone(for: zoneID) } catch let ckError as CKError where [.zoneNotFound, .userDeletedZone].contains(ckError.code) { // createZone is a helper function try await createZone(zoneID: zoneID, context: context) } This works great, but every time I do this, an error is logged in CloudKit Console, which creates a lot of noise and makes it harder to see real errors. Is there a way to do this without explicitly triggering a CloudKit error? I just found CKDatabase#recordZones(for:) (docs), which seems like it returns an empty array instead of throwing an error if the zone doesn't exist. Will calling that and looking for a non-empty array work just as well, but without logging lots of errors in the console?

I've noticed that SwiftData's @Relationship seems to potentially cause application crashes. The crash error is shown in the image. Since this crash appears to be random and I cannot reproduce it under specific circumstances, I can only temporarily highlight that this issue seems to exist. @Model final class TrainInfo { @Relationship(deleteRule: .cascade, inverse: \StopStation.trainInfo) var stations: [StopStation]? } @Model final class StopStation { @Relationship var trainInfo: TrainInfo? } /// some View var origin: StopStationDisplayable? { if let train = train as? TrainInfo { return train.stations?.first(where: { $0.isOrigin }) ?? train.stations?.first(where: { $0.isStarting }) } return nil } // Some other function or property func someFunction() { if let origin, let destination { // Function implementation } }

I'm using SwiftData with CloudKit private database. I was able to identify the error on my device by debugging in Xcode with com.apple.CoreData.SQLDebug flag. However, in Production, I couldn't find a way to get the cause of errors. I tried inspecting the error coming from eventChangedNotification. The NSPersistentCloudKitContainer.Event error does not contain any underlying error (neither CKError.userInfo nor in NSError.underlyingError). It only reports a partial failure with CKErrorDomain code 2. If a user encounter an error, there seems to be no way to retrieve the error details. Is there any way to access the error details or logs in Production?

Hello, In our app, we’ve modeled our schema using inheritance introduced in iOS 26.0, and we’re implementing SwiftData History to re-fetch models only when necessary. @Model public class Transaction { @Attribute(.preserveValueOnDeletion) public var date: Date = Date() public var amount: Double = 0 public var memo: String? } @Model public final class Spending: Transaction { public var installmentIndex: Int = 1 public var installment: Int = 1 public var installmentID: UUID? } If data has been deleted from database, we need to check a date property to determine whether to re-fetch datas. To do this, we added the preserveValueOnDeletion attribute to date property so we could retrieve it from the History tombstone value. However, after adding this attribute, a crash occurs. There is a console log Could not cast value of type 'Swift.ReferenceWritableKeyPath<Shared.ModelSchemaV5.Transaction, Foundation.Date>' (0x106bf8328) to 'Swift.PartialKeyPath<Shared.ModelSchemaV5.Spending>' (0x1094f21d8). and error log attached StrictMoneyChecking-2025-11-07-105108.txt I also tried this in the recent SampleTrip app, and fetching all history after a deletion causes the same crash. Is this issue currently being worked on or under investigation?

Am I misunderstanding the expected behavior here, or is there a bug in the behavior of @Attribute(.ephemeral) tagged SwiftData model properties? The documentation for .ephemeral says "Track changes to this property but do not persist". I started using .ephemeral because @Transient was inhibiting SwiftUI from reacting to changes to the property through @Observable. I am updating the value of my @Attribute(.ephemeral) property about once a second and I am seeing corresponding console log output showing the property as part of the generated CKRecord object. I then confirmed in the CloudKit dev portal that the .ephemeral property was added to the Record schema and contains real values. The behavior seems as though the .ephemeral property is being completely ignored. This is observed in a new Xcode project using SwiftData with CloudKit, Xcode 16.2, macOS 15.3.1 and during Build & Run testing on physical devices.

The following complex migration consistently crashes the app with the following error: SwiftData/PersistentModel.swift:726: Fatal error: What kind of backing data is this? SwiftData._KKMDBackingData<SwiftDataMigration.ItemSchemaV1.ItemList> My app relies on a complex migration that involves these optional 1 to n relationships. Theoretically I could not assign the relationships in the willMigrate block but afterwards I am not able to tell which list and items belonged together. Steps to reproduce: Run project Change typealias CurrentSchema to ItemSchemaV2 instead of ItemSchemaV1. Run project again -> App crashes My setup: Xcode Version 16.2 (16C5032a) MacOS Sequoia 15.4 iPhone 12 with 18.3.2 (22D82) Am I doing something wrong or did I stumble upon a bug? I have a demo Xcode project ready but I could not upload it here so I put the code below. Thanks for your help typealias CurrentSchema = ItemSchemaV1 typealias ItemList = CurrentSchema.ItemList typealias Item = CurrentSchema.Item @main struct SwiftDataMigrationApp: App { var sharedModelContainer: ModelContainer = { do { return try ModelContainer(for: ItemList.self, migrationPlan: MigrationPlan.self) } catch { fatalError("Could not create ModelContainer: \(error)") } }() var body: some Scene { WindowGroup { ContentView() } .modelContainer(sharedModelContainer) } } This is the migration plan enum MigrationPlan: SchemaMigrationPlan { static var schemas: [any VersionedSchema.Type] { [ItemSchemaV1.self, ItemSchemaV2.self] } static var stages: [MigrationStage] = [ MigrationStage.custom(fromVersion: ItemSchemaV1.self, toVersion: ItemSchemaV2.self, willMigrate: { context in print("Started migration") let oldlistItems = try context.fetch(FetchDescriptor<ItemSchemaV1.ItemList>()) for list in oldlistItems { let items = list.items.map { ItemSchemaV2.Item(timestamp: $0.timestamp)} let newList = ItemSchemaV2.ItemList(items: items, name: list.name, note: "This is a new property") context.insert(newList) context.delete(list) } try context.save() // Crash indicated here print("Finished willMigrate") }, didMigrate: { context in print("Did migrate successfully") }) ] } The versioned schemas enum ItemSchemaV1: VersionedSchema { static var versionIdentifier = Schema.Version(1, 0, 0) static var models: [any PersistentModel.Type] { [Item.self] } @Model final class Item { var timestamp: Date var list: ItemSchemaV1.ItemList? init(timestamp: Date) { self.timestamp = timestamp } } @Model final class ItemList { @Relationship(deleteRule: .cascade, inverse: \ItemSchemaV1.Item.list) var items: [Item] var name: String init(items: [Item], name: String) { self.items = items self.name = name } } } enum ItemSchemaV2: VersionedSchema { static var versionIdentifier = Schema.Version(2, 0, 0) static var models: [any PersistentModel.Type] { [Item.self] } @Model final class Item { var timestamp: Date var list: ItemSchemaV2.ItemList? init(timestamp: Date) { self.timestamp = timestamp } } @Model final class ItemList { @Relationship(deleteRule: .cascade, inverse: \ItemSchemaV2.Item.list) var items: [Item] var name: String var note: String init(items: [Item], name: String, note: String = "") { self.items = items self.name = name self.note = note } } } Last the ContentView: struct ContentView: View { @Query private var itemLists: [ItemList] var body: some View { NavigationSplitView { List { ForEach(itemLists) { list in NavigationLink { List(list.items) { item in Text(item.timestamp.formatted(date: .abbreviated, time: .complete)) } .navigationTitle(list.name) } label: { Text(list.name) } } } .navigationTitle("Crashing migration demo") .onAppear { if itemLists.isEmpty { for index in 0..<10 { let items = [Item(timestamp: Date.now)] let listItem = ItemList(items: items, name: "List No. \(index)") modelContext.insert(listItem) } try! modelContext.save() } } } detail: { Text("Select an item") } } }

Experiencing a crash that is only reproducible on TestFlight or AppStore version of the app, note this does not happen when running from Xcode. I've isolated the problem to sort argument being added to @Query that fetches a model that sorts based on inherited property. To reproduce: @Model class SuperModel { var createdAt: Date = .now } @available(macOS 26.0, *) @Model class SubModel: SuperModel { } @Query(sort: \SubModel.createdAt, animation: .default) private var models: [SubModel]

I'm having some issues where only a subset of records appear in CloudKit dashboard after I have saved some records in my iOS app using NSPersistentCloudKitContainer. I have noticed that when I'm running my app using the development environment of my CloudKit container everything works smoothly and is uploaded as expected but when I'm using the production environment only a subset of records are actually uploaded. I'm pulling my hair on how to debug this. -com.apple.CoreData.CloudKitDebug and -com.apple.CoreData.SQLDebug pukes out too much info in the console for me to pinpoint any issue.

Definitely one of the stranger quirks of SwiftData I've come across. I have a ScriptView that shows Line entities related to a Production, and a TextEnterScriptView that’s presented in a sheet to input text. I’m noticing that every time I type in the TextEditor within TextEnterScriptView, a new Line shows up in ScriptView — even though I haven’t explicitly inserted it into the modelContext. I'm quite confused because even though I’m only assigning a new Line to a local @State array in TextEnterScriptView, every keystroke in the TextEditor causes a duplicate Line to appear in ScriptView. In other words, Why is SwiftData creating new Line entities every time I type in the TextEditor, even though I’m only assigning to a local @State array and not explicitly inserting them into the modelContext? Here is my minimal reproducible example: import SwiftData import SwiftUI @main struct testApp: App { var body: some Scene { WindowGroup { ContentView() .modelContainer(for: Line.self, isAutosaveEnabled: false) } } } struct ContentView: View { @Environment(\.modelContext) var modelContext @Query(sort: \Production.title) var productions: [Production] var body: some View { NavigationStack { List(productions) { production in NavigationLink(value: production) { Text(production.title) } } .navigationDestination(for: Production.self) { production in ScriptView(production: production) } .toolbar { Button("Add", systemImage: "plus") { let production = Production(title: "Test \(productions.count + 1)") modelContext.insert(production) do { try modelContext.save() } catch { print(error) } } } .navigationTitle("Productions") } } } struct ScriptView: View { @Query private var lines: [Line] let production: Production @State private var isShowingSheet: Bool = false var body: some View { List { ForEach(lines) { line in Text(line.content) } } .toolbar { Button("Show Sheet") { isShowingSheet.toggle() } } .sheet(isPresented: $isShowingSheet) { TextEnterScriptView(production: production) } } } struct TextEnterScriptView: View { @Environment(\.dismiss) var dismiss @State private var text = "" @State private var lines: [Line] = [] let production: Production var body: some View { NavigationStack { TextEditor(text: $text) .onChange(of: text, initial: false) { lines = [Line(content: "test line", production: production)] } .toolbar { Button("Done") { dismiss() } } } } } @Model class Production { @Attribute(.unique) var title: String @Relationship(deleteRule: .cascade, inverse: \Line.production) var lines: [Line] = [] init(title: String) { self.title = title } } @Model class Line { var content: String var production: Production? init(content: String, production: Production?) { self.content = content self.production = production } }

In the future, is there any plans to have AppMigrationKit for macOS-Windows cross transfers (or Linux, ChromeOS, HarmonyOS NEXT, etc)? Additionally, will the migration framework remain just iOS <-> Android or will it extend to Windows tablets, ChromeOS Tablets, HarmonyOS NEXT, KaiOS, Series 30+, Linux mobile, etc.

Description: I'm experiencing a critical issue with SwiftData custom migrations where objects created during migration appear to be inserted successfully but aren't persisted or found by queries after migration completes. The migration logs show objects being created, but subsequent queries return zero results. Problem Details: I'm migrating from schema version V2 to V3, which involves: Renaming Person class to GroupData Keeping the same data structure but changing the class name Using a custom migration stage to copy data from old to new schema Migration Code: swift static let migrationV2toV3 = MigrationStage.custom( fromVersion: LinkMapV2.self, toVersion: LinkMapV3.self, willMigrate: { context in do { let persons = try context.fetch(FetchDescriptor<LinkMapV2.Person>()) print("Found (persons.count) Person objects to migrate") // ✅ Shows 11 objects for person in persons { let newGroup = LinkMapV3.GroupData( id: person.id, // Same UUID name: person.name, // ... other properties ) context.insert(newGroup) print("Inserted GroupData: '\(newGroup.name)'") // ✅ Confirms insertion } try context.save() // ✅ No error thrown print("Successfully migrated \(persons.count) objects") // ✅ Confirms save } catch { print("Migration error: \(error)") } }, didMigrate: { context in do { let groups = try context.fetch(FetchDescriptor<LinkMapV3.GroupData>()) print("Final GroupData count: \(groups.count)") // ❌ Shows 0 objects! } catch { print("Verification error: \(error)") } } ) Console Output: text === MIGRATION STARTED === Found 11 Person objects to migrate Migrating Person: 'Riverside of pipewall' with ID: 7A08C633-4467-4F52-AF0B-579545BA88D0 Inserted new GroupData: 'Riverside of pipewall' ... (all 11 objects processed) ... === MIGRATION COMPLETED === Successfully migrated 11 Person objects to GroupData === MIGRATION VERIFICATION === New GroupData count: 0 // ❌ PROBLEM: No objects found! What I've Tried: Multiple context approaches: Using the provided migration context Creating a new background context with ModelContext(context.container) Using context.performAndWait for thread safety Different save strategies: Calling try context.save() after insertions Letting SwiftData handle saving automatically Multiple save calls at different points Verification methods: Checking in didMigrate closure Checking in app's ContentView after migration completes Using both @Query and manual FetchDescriptor Schema variations: Direct V2→V3 migration Intermediate V2.5 schema with both classes Lightweight migration with @Attribute(originalName:) Current Behavior: Migration runs without errors Objects appear to be inserted successfully context.save() completes without throwing errors But queries in didMigrate and post-migration return empty results The objects seem to exist in a temporary state that doesn't persist Expected Behavior: Objects created during migration should be persisted and queryable Post-migration queries should return the migrated objects Data should be available in the main app after migration completes Environment: Xcode 16.0+ iOS 18.0+ SwiftData Swift 6.0+ Key Questions: Is there a specific way migration contexts should be handled for data to persist? Are there known issues with object persistence in custom migrations? Should we be using a different approach for class renaming migrations? Is there a way to verify that objects are actually being written to the persistent store? The migration appears to work perfectly until the verification step, where all created objects seem to vanish. Any guidance would be greatly appreciated! Additional Context from my investigation: I've noticed these warning messages during migration that might be relevant: text SwiftData.ModelContext: Unbinding from the main queue. This context was instantiated on the main queue but is being used off it. error: Persistent History (76) has to be truncated due to the following entities being removed: (Person) This suggests there might be threading or context lifecycle issues affecting persistence. Let me know if you need any additional information about my setup or migration configuration!

I am working with SwiftData and get the below error. I can't find any documentation on it to see what to fix. Any help would be appreciated. Fatal error: This relationship already has a value but it's not the target:

Hi all, I've contacted Apple about this privately but I wanted to post this publicly too just to see if anyone else is experiencing the same issue. We use CloudKit to store "documents" (we'll call them) for our users. We use it directly, not via CoreData etc but through the lower level APIs. This has been working great for the last 9 months or so. Since a few days ago we've started receiving reports from users that their data has disappeared without a trace from their app. Obviously this is very serious and severe for us. We keep a local copy of the users data but if CloudKit tells us this data has been deleted we remove that local copy to keep in sync. Nothing has changed client side in terms of our code, and the only way we can see that could cause this, is a fetch that we perform asking for a list of the users "documents" is returning no rows/results, or possibly returning rows with invalid or missing fields. We have about 30,000 active users per day (1.5m requests/day) using CloudKit and we have only a handful of reports of this. Again this only started happening this week after 9 months of good service. Has anyone else noticed anything "strange" lately, fetches returning empty? fields missing? Is anyone at Apple aware of any recent changes to CloudKit? or outages? We're really unsure how or who should handle this and who we can escalate to? Any help appreciated. We have a workaround/mitigation on the way through review at the moment but this is a really big problem for us if we can't rely on CloudKit to remember users data reliably.

I'm experiencing a critical issue with SwiftData custom migrations where objects created during migration appear to be inserted successfully but aren't persisted or found by queries after migration completes. The migration logs show objects being created, but subsequent queries return zero results. I'm migrating from schema version V2 to V2_5, which involves: Renaming Person class to GroupData Keeping the same data structure but changing the class name while keeping the old class. Using a custom migration stage to copy data from old to new schema Below is an extract of my two schema and migration plan: Environment: Xcode 16.0, iOS 18.0, Swift 6.0 SchemaV2 enum LinkMapV2: VersionedSchema { static let versionIdentifier: Schema.Version = .init(2, 0, 0) static var models: [any PersistentModel.Type] { [AnnotationData.self, Person.self, History.self] } @Model final class Person { @Attribute(.unique) var id: UUID var name: String var photo: String var requirement: String var statue: Bool var annotationId: UUID? var number: Int = 0 init(id: UUID = UUID(), name: String = "", photo: String = "", requirement: String = "", status: Bool = false, annotationId: UUID? = nil, number: Int = 0) { self.id = id self.name = name self.photo = photo self.requirement = requirement self.statue = status self.annotationId = annotationId self.number = number } } } Schema V2_5 static let versionIdentifier: Schema.Version = .init(2, 5, 0) static var models: [any PersistentModel.Type] { [AnnotationData.self, Person.self, GroupData.self, History.self] } // Keep the old Person model for migration @Model final class Person { @Attribute(.unique) var id: UUID var name: String var photo: String var requirement: String var statue: Bool var annotationId: UUID? var number: Int = 0 init(id: UUID = UUID(), name: String = "", photo: String = "", requirement: String = "", status: Bool = false, annotationId: UUID? = nil, number: Int = 0) { self.id = id self.name = name self.photo = photo self.requirement = requirement self.statue = status self.annotationId = annotationId self.number = number } } // Add the new GroupData model that mirrors Person @Model final class GroupData { @Attribute(.unique) var id: UUID var name: String var photo: String var requirement: String var status: Bool var annotationId: UUID? var number: Int = 0 init(id: UUID = UUID(), name: String = "", photo: String = "", requirement: String = "", status: Bool = false, annotationId: UUID? = nil, number: Int = 0) { self.id = id self.name = name self.photo = photo self.requirement = requirement self.status = status self.annotationId = annotationId self.number = number } } } Migration Plan static let migrationV2toV2_5 = MigrationStage.custom( fromVersion: LinkMapV2.self, toVersion: LinkMapV2_5.self, willMigrate: { context in do { let persons = try context.fetch(FetchDescriptor<LinkMapV2.Person>()) print("=== MIGRATION STARTED ===") print("Found \(persons.count) Person objects to migrate") guard !persons.isEmpty else { print("No Person data requires migration") return } for person in persons { print("Migrating Person: '\(person.name)' with ID: \(person.id)") let newGroup = LinkMapV2_5.GroupData( id: person.id, // Keep the same ID name: person.name, photo: person.photo, requirement: person.requirement, status: person.statue, annotationId: person.annotationId, number: person.number ) context.insert(newGroup) print("Inserted new GroupData: '\(newGroup.name)'") // Don't delete the old Person yet to avoid issues // context.delete(person) } try context.save() print("=== MIGRATION COMPLETED ===") print("Successfully migrated \(persons.count) Person objects to GroupData") } catch { print("=== MIGRATION ERROR ===") print("Migration failed with error: \(error)") } }, didMigrate: { context in do { // Verify migration in didMigrate phase let groups = try context.fetch(FetchDescriptor<LinkMapV2_5.GroupData>()) let oldPersons = try context.fetch(FetchDescriptor<LinkMapV2_5.Person>()) print("=== MIGRATION VERIFICATION ===") print("New GroupData count: \(groups.count)") print("Remaining Person count: \(oldPersons.count)") // Now delete the old Person objects for person in oldPersons { context.delete(person) } if !oldPersons.isEmpty { try context.save() print("Cleaned up \(oldPersons.count) old Person objects") } // Print all migrated groups for debugging for group in groups { print("Migrated Group: '\(group.name)', Status: \(group.status), Number: \(group.number)") } } catch { print("Migration verification error: \(error)") } } ) And I've attached console output below: Console Output

If an app is using top-level models, meaning they exist outside the VersionedSchema enum, is it safe to keep them outside of the VersionedSchema enum and use a migration plan for simple migrations. Moving the models within the VersionedSchema enum I believe would change the identity of the models and result in data being lost, although correct me if I'm wrong in that statement. The need presently is just to add another variable to the model and then set that variable within the init function: var updateId = UUID() The app is presently in TestFlight although I'd like to preserve data for users that are currently using the app. The data within SwiftData is synchronized with CloudKit and so I'd also like to avoid any impact to synchronization. Any thoughts on this would be greatly appreciated.

Hi, thank you for your reply. I have checked and confirmed that all AppleUser entity fields (id, name, email, password, createdAt) are optional, relationships (posts, comments) are optional, and I assign values when creating a new object, but Core Data still throws a nilError during registration; I have uploaded my project to GitHub for your reference here: https://github.com/Kawiichao/job. If reviewing it requires any payment, please let me know in advance. Thank you very much for your kind offer—I really appreciate it!

I'm setting up App Entities for my SwiftData models and I'm not sure about the best way to reference SwiftData model properties in the AppEntity. I have a SwiftData model with many properties: @Model final class Contact { @Attribute(.unique) var id: UUID = UUID() var name: String var phoneNumber: String var email: String var website: URL? var birthday: Date? var notes: String // ... many more properties } I want to expose these properties on my AppEntity so they're available for system features, such as giving Apple Intelligence more context about on-screen content. struct ContactEntity: AppEntity { var id: UUID @Property(title: "Name") var name: String @Property(title: "Phone") var phoneNumber: String @Property(title: "Email") var email: String // ... all the other properties } I couldn't find guidance in the documentation for this specific situation. I've considered two approaches: Add @Property variables to the AppEntity for each SwiftData model property and copy all values from the SwiftData model to the AppEntity in the AppEntity initializer — but I recall this being discouraged in previous WWDC sessions since it duplicates data and can become stale Use @ComputedProperty to fetch the model and access the single properties — this seems like an alternative, but fetching the entire model just to access individual properties doesn't feel right What is the recommended approach when SwiftData is the data source? Thank you!

I’m running into a CloudKit sync issue that I can’t reconcile after multiple rebuilds, TestFlight uploads, and entitlement verification, and I’m hoping for guidance on what I’m missing or whether this is expected behavior. Context App: RankSpinnah Platforms: iOS + macOS Distribution: TestFlight Xcode: 26.x Both apps use the same bundle identifier, same container, and same Apple Developer team Automatic signing enabled; Xcode-managed profiles CloudKit capability enabled for both targets Both builds install and run correctly from TestFlight on: iPhone 17 Pro Apple-silicon Mac (M5 MacBook Pro) The Problem CloudKit data does not sync at all between devices. On both iOS and macOS, CloudKit queries return no records, and I consistently see this error: Field 'recordName' is not marked queryable This occurs even when querying for records that should exist and after fresh installs on both devices. What I’ve Verified Same iCloud account signed in on both devices CloudKit container exists and is enabled App Sandbox enabled with network access CloudKit entitlements present in the signed app (verified from the archived .app) TestFlight builds are using the correct container Rebuilt and re-uploaded after version bump (1.2.0 / build 2026.02.03) Both iOS and macOS apps successfully uploaded and installed via TestFlight Despite this, no data syncs, and the queryable error persists. What I’m Unsure About Whether recordName is expected to be non-queryable in production schemas Whether TestFlight + CloudKit requires an explicit production schema deploy beyond what Xcode manages Whether this indicates a schema mismatch between development and production environments Or whether something subtle changed in recent Xcode / CloudKit behavior Ask Can someone clarify: Whether querying by recordName should work in production CloudKit What specifically causes the “Field recordName is not marked queryable” error in TestFlight builds What steps are required to ensure CloudKit schemas are correctly deployed for cross-platform sync At this point I feel like I’m missing one critical step, but I can’t identify what it is. Thanks in advance for any guidance.

Hey everyone I just ran into an issue where I couldn't sync the model below fully by using CloudKit, enum LinkMapV3_1: VersionedSchema { static let versionIdentifier: Schema.Version = .init(3, 1, 0) static var models: [any PersistentModel.Type] { [AnnotationData.self, GroupData.self, Item.self, Deployment.self, History.self] } // MARK: - Data @Model class AnnotationData { var name: String = "" var longitude: Double = 0.0 var latitude: Double = 0.0 var order: Int = -1 var level: Int = 1 var detail: String = "" @Relationship(deleteRule: .nullify, inverse: \GroupData.annotation) var groups: [GroupData]? @Relationship(deleteRule: .nullify, inverse: \AnnotationData.to) var from: AnnotationData? var to: AnnotationData? var history: History? } // MARK: - History @Model class History { var id: UUID = UUID() var timestamp: Date = Date() @Relationship(deleteRule: .nullify, inverse: \AnnotationData.history) var annotations: [AnnotationData]? @Relationship(deleteRule: .nullify, inverse: \GroupData.history) var groups: [GroupData]? @Relationship(deleteRule: .nullify, inverse: \Item.history) var items: [Item]? @Relationship(deleteRule: .nullify, inverse: \Deployment.history) var deployment: Deployment? var formattedDate: String { let formatter = DateFormatter() formatter.dateStyle = .medium formatter.timeStyle = .short return formatter.string(from: timestamp) } var timeAgo: String { let formatter = RelativeDateTimeFormatter() formatter.unitsStyle = .abbreviated return formatter.localizedString(for: timestamp, relativeTo: Date()) } } } So when trying to sync with the code in documentation let modelContainer: ModelContainer init() { let config = ModelConfiguration() typealias vs = LinkMapV3_1 do { #if DEBUG // Use an autorelease pool to make sure Swift deallocates the persistent // container before setting up the SwiftData stack. try autoreleasepool { let desc = NSPersistentStoreDescription(url: config.url) let opts = NSPersistentCloudKitContainerOptions(containerIdentifier: "iCloud.name.Endsunset.LinkMap.SwiftData.v1") desc.cloudKitContainerOptions = opts // Load the store synchronously so it completes before initializing the // CloudKit schema. desc.shouldAddStoreAsynchronously = false if let mom = NSManagedObjectModel.makeManagedObjectModel(for: [vs.AnnotationData.self, vs.GroupData.self, vs.Item.self, vs.Deployment.self, vs.History.self]) { let container = NSPersistentCloudKitContainer(name: "LinkMap", managedObjectModel: mom) container.persistentStoreDescriptions = [desc] container.loadPersistentStores {_, err in if let err { fatalError(err.localizedDescription) } } // Initialize the CloudKit schema after the store finishes loading. try container.initializeCloudKitSchema() // Remove and unload the store from the persistent container. if let store = container.persistentStoreCoordinator.persistentStores.first { try container.persistentStoreCoordinator.remove(store) } } } #endif modelContainer = try ModelContainer(for: vs.AnnotationData.self, vs.GroupData.self, vs.Item.self, vs.Deployment.self, vs.History.self, configurations: config) } catch { fatalError(error.localizedDescription) } } The output is Console Output Where you can see Output Extract Optional arrays with @Relationship are missing, and the entry of record types on cloudkit database container are also missing it. When I attempt to insert an annotation, I got SwiftData/PersistentModel.swift:559: Fatal error: This KeyPath does not appear to relate AnnotationData to anything - \AnnotationData.groups It gets more suspicious when restart the app and try again, the above error end with "AnnotationData.history", and if I tried again the above error end with "AnnotationData.from"... and so on. No matter how my app stop working.