I'm working with the FamilyControls API and am running into an issue with sharing ActivityTokens between devices in the same family sharing network. Based on this documentation, ActivityTokens are only accessible and readable by other members in the family sharing network. My app is based on the idea that if one user selects the Games category in the FamilyActivityPicker, then this token can be shared with another device in the same family-sharing network and this other device can read and display the category. So my question is: If a user in the network selects an activity category in the FamilyActivityPicker, can this category token be shared, read, and used by another user in the family-sharing network?

Currently, I have an Unversioned Schema, and lightweight changes are automatically applied to the Models. However, I'm planning to transition to a VersionedSchema, and I have a few questions: Do I need to write all lightweight migrations in the Migration Plan? or is it automatically applied like the Unversioned Schema? What happens if I do not create a lightweight migration? and just directly do lightweight changes to the latest VersionedSchema (example: Add a new property)?

Hello, I recently switched my app from flutter which was using sqlite3 database. I would like to migrate my existing users to SwiftData. The issue is I do not know where to start in finding the database for the current users, reading the data and inserting into the SwiftData schema. I tried searching but not clear on how to proceed. Any help pointing in the right direction would be great. Thanks.

I'm using SwiftData, and I'm using iCloud's CloudKit feature to back up my data. The problem here is that once you start backing up your data, you can't erase it completely. Even if the user adds 4 data and erases 4 again, I'm using about 2.5kb. I don't know how the user using the app will accept this. I'm trying to provide the user with the ability to erase data at once, what should I do??

I have a Core Data app on the App Store that places its persistent store in the default location within the Application Support directory. At some point, I add widgets to the app while utilizing SwiftData. I create a widget extension and the app group to link both targets. I migrate my persistent store from the default location to the app group container directory. Now, the SwiftData code pointing to the shared container in the widget extension can query data. Here's the sample project for illustration up to this point. Then, I decided to get rid of the Core Data code entirely. Move everything in the main target to SwiftData. I need to keep my persistence controller object, however, because I can never assume that the entirety of my user base has migrated. I do need to ditch the Core Data model file. Otherwise, my new SwiftData models would conflict with the auto-generated ones from that file. But once I do that, my migration code breaks. I can't set up a persistent container without the model. And I need the container for migration. SwiftData has no native interface to migrate the store to a new location. There is a line in the documentation stating that the framework copies the store to an app group container automatically. But I wasn't able to verify that claim.

I am trying to add a custom JSON DataStore and DataStoreConfiguration for SwiftData. Apple kindly provided some sample code in the WWDC24 session, "Create a custom data store with SwiftData", and (once updated for API changes since WWDC) that works fine. However, when I try to add a relationship between two classes, it fails. Has anyone successfully made a JSONDataStore with a relationship? Here's my code; firstly the cleaned up code from the WWDC session: import SwiftData final class JSONStoreConfiguration: DataStoreConfiguration { typealias Store = JSONStore var name: String var schema: Schema? var fileURL: URL init(name: String, schema: Schema? = nil, fileURL: URL) { self.name = name self.schema = schema self.fileURL = fileURL } static func == (lhs: JSONStoreConfiguration, rhs: JSONStoreConfiguration) -> Bool { return lhs.name == rhs.name } func hash(into hasher: inout Hasher) { hasher.combine(name) } } final class JSONStore: DataStore { typealias Configuration = JSONStoreConfiguration typealias Snapshot = DefaultSnapshot var configuration: JSONStoreConfiguration var name: String var schema: Schema var identifier: String init(_ configuration: JSONStoreConfiguration, migrationPlan: (any SchemaMigrationPlan.Type)?) throws { self.configuration = configuration self.name = configuration.name self.schema = configuration.schema! self.identifier = configuration.fileURL.lastPathComponent } func save(_ request: DataStoreSaveChangesRequest<DefaultSnapshot>) throws -> DataStoreSaveChangesResult<DefaultSnapshot> { var remappedIdentifiers = [PersistentIdentifier: PersistentIdentifier]() var serializedData = try read() for snapshot in request.inserted { let permanentIdentifier = try PersistentIdentifier.identifier(for: identifier, entityName: snapshot.persistentIdentifier.entityName, primaryKey: UUID()) let permanentSnapshot = snapshot.copy(persistentIdentifier: permanentIdentifier) serializedData[permanentIdentifier] = permanentSnapshot remappedIdentifiers[snapshot.persistentIdentifier] = permanentIdentifier } for snapshot in request.updated { serializedData[snapshot.persistentIdentifier] = snapshot } for snapshot in request.deleted { serializedData[snapshot.persistentIdentifier] = nil } try write(serializedData) return DataStoreSaveChangesResult<DefaultSnapshot>(for: self.identifier, remappedIdentifiers: remappedIdentifiers) } func fetch<T>(_ request: DataStoreFetchRequest<T>) throws -> DataStoreFetchResult<T, DefaultSnapshot> where T : PersistentModel { if request.descriptor.predicate != nil { throw DataStoreError.preferInMemoryFilter } else if request.descriptor.sortBy.count > 0 { throw DataStoreError.preferInMemorySort } let objs = try read() let snapshots = objs.values.map({ $0 }) return DataStoreFetchResult(descriptor: request.descriptor, fetchedSnapshots: snapshots, relatedSnapshots: objs) } func read() throws -> [PersistentIdentifier : DefaultSnapshot] { if FileManager.default.fileExists(atPath: configuration.fileURL.path(percentEncoded: false)) { let decoder = JSONDecoder() decoder.dateDecodingStrategy = .iso8601 let data = try decoder.decode([DefaultSnapshot].self, from: try Data(contentsOf: configuration.fileURL)) var result = [PersistentIdentifier: DefaultSnapshot]() data.forEach { s in result[s.persistentIdentifier] = s } return result } else { return [:] } } func write(_ data: [PersistentIdentifier : DefaultSnapshot]) throws { let encoder = JSONEncoder() encoder.dateEncodingStrategy = .iso8601 encoder.outputFormatting = [.prettyPrinted, .sortedKeys] let jsonData = try encoder.encode(data.values.map({ $0 })) try jsonData.write(to: configuration.fileURL) } } The data model classes: import SwiftData @Model class Settings { private(set) var version = 1 @Relationship(deleteRule: .cascade) var hack: Hack? = Hack() init() { } } @Model class Hack { var foo = "Foo" var bar = 42 init() { } } Container: lazy var mainContainer: ModelContainer = { do { let url = // URL to file let configuration = JSONStoreConfiguration(name: "Settings", schema: Schema([Settings.self, Hack.self]), fileURL: url) return try ModelContainer(for: Settings.self, Hack.self, configurations: configuration) } catch { fatalError("Container error: \(error.localizedDescription)") } }() Load function, that saves a new Settings JSON file if there isn't an existing one: @MainActor func loadSettings() { let mainContext = mainContainer.mainContext let descriptor = FetchDescriptor<Settings>() let settingsArray = try? mainContext.fetch(descriptor) print("\(settingsArray?.count ?? 0) settings found") if let settingsArray, let settings = settingsArray.last { print("Loaded") } else { let settings = Settings() mainContext.insert(settings) do { try mainContext.save() } catch { print("Error saving settings: \(error)") } } } The save operation creates a JSON file, which while it isn't a format I would choose, is acceptable, though I notice that the "hack" property (the relationship) doesn't have the correct identifier. When I run the app again to load the data, I get an error (that there wasn't room to include in this post). Even if I change Apple's code to not assign a new identifier, so the relationship property and its pointee have the same identifier, it still doesn't load. Am I doing something obviously wrong, or are relationships not supported in custom data stores?

I've developed an app that allow me to send messages to all users by entering a record in Public database. On each users device, the app takes that Public record and creates a record in their Private database to track the Read and Deleted status. It works flawlessly on the simulator and about 1/3 of the devices enrolled in my TestFlight. The other 2/3 are unable to write to their Private database. In fact, the CKContainer.default().privateCloudDatabase.save() operation causes the app to crash if I let it run. I've looked at every Google link and I just can't figure out why this works for 1/3 of the users, but not the other 2/3. Incidentally, the 2/3 of the group that can't save to their Private database are also unable to save their Notification Subscription. All devices are running iOS 18.0 or better iPhone 11 through 16 in testing pool. Each portion of the working/not working group are a mix of iPhone versions. if !found && checkIcloudStatus() { CKContainer.default().privateCloudDatabase.save(loadPrivateData(n: processedMessages[index].recordName)) { returnedRecord, returnedError in print("Adding new message to Private and error is: \(String(describing: returnedError))") DispatchQueue.main.async { self.processedMessages[index].record = returnedRecord ?? CKRecord(recordType: "messages_private") self.processedMessages[index].unRead = true self.processedMessages[index].deleted = false } } } func loadPrivateData(n: String) -> CKRecord { let record = CKRecord(recordType: "messages_private") record["deleted"] = "false" record["messageId"] = n record["unRead"] = "true" return record }

I got a preview crash info as this: *** crashed due to fatalError in PersistentModel.swift at line 559. This KeyPath does not appear to relate RecordInfo to anything - \RecordInfo.<computed 0x00000001921dfb4e (Array<SomeInfo>)> If I change preview device to iPhoneSE, It is no crash. I think the reason is I have some dirty data in iPhone16 Pro preview device. If I'm right and how to delete it? Model of RecordInfo like this: @Model class RecordInfo { @Relationship(deleteRule: .cascade) var someInfo:[SomeInfo] } @Model class SomeInfo { var date: Date var info: String }

While reading the developer documentation article Adopting SwiftData for a Core Data App, one particular line piqued my interest. For apps that evolve from a version that doesn’t have any app group container to a version that has one, SwiftData copies the existing store to the app group container. Given how troublesome it has been to migrate the Core Data persistent store to an app group container, I decided to try this out myself. I created an Xcode project using the default Core Data template. I then added a few Item objects with timestamps. There, I had what we would consider a regular Core Data app. I then created a widget extension for this app since this is one of the most common uses for adopting an app group in an Xcode project. After that, I linked the main target with the widget extension using an app group. In the widget extension, I tried to fetch the Item objects. I utilized the SwiftData code in the sample project associated with the article above. struct Provider: TimelineProvider { private let modelContainer: ModelContainer init() { let appGroupContainerID = "group.com.genebogdanovich.CoreDataSwiftDataAppGroup" guard let appGroupContainer = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: appGroupContainerID) else { fatalError("Shared file container could not be created.") } let url = appGroupContainer.appendingPathComponent("CoreDataSwiftDataAppGroup.sqlite") print("\(url)") do { modelContainer = try ModelContainer(for: Item.self, configurations: ModelConfiguration(url: url)) } catch { fatalError("Failed to create the model container: \(error)") } } } func getTimeline(in context: Context, completion: @escaping (Timeline<Entry>) -> ()) { Task { @MainActor in let fetchDescriptor = FetchDescriptor<Item>() let items: [Item] = try! modelContainer.mainContext.fetch(fetchDescriptor) print(items) let entry = SimpleEntry(date: .now, emoji: "😀", count: items.count) let timeline = Timeline(entries: [entry], policy: .never) completion(timeline) } } The fetch yielded no results. However, as I explored the app group directory in the file system, I found a .sqlite file. That is interesting because SwiftData creates .store files by default. So, I am guessing that SwiftData did copy something. Or the ModelContainer initializer just created another empty SQLite file since the fetch returned zero results. I would highly appreciate someone elaborating on that quote from the documentation.

Both appleIDs(create and modify/save) sign in iCloud. I use the following code to modify and save records: self.containerIdentifier).publicCloudDatabase database.fetch(withRecordID: CKRecord.ID(recordName:groupID), completionHandler: { record, error in if error == nil && record != nil { if let iDs : [String] = record!.object(forKey: "memberIDs") as? Array { if iDs.count < self.maxMemberCount { if let mems: [String] = record!.object(forKey: "memberNames") as? Array { if !(mems as NSArray).contains(name) { var members = mems members.append(name) record!.setObject(members as CKRecordValue, forKey: "memberNames") var iDs : [String] = record!.object(forKey: "memberIDs") as! Array iDs.append(self.myMemberID) record!.setObject(iDs as CKRecordValue, forKey:"memberIDs") database.save(record!, completionHandler: { record, error in if error == nil { } else { completion(error as NSError?) dPrint("Error : \(String(describing: error))") } }) }else{ let DBError : NSError = NSError(domain: "DBError", code: 89, userInfo: ["localizedDescription": NSLocalizedString("Your nickname already used.", comment:"")]) completion(DBError) print("change your nickname") } }else{ print("group DB error") let DBError : NSError = NSError(domain: "DBError", code: 88, userInfo: ["localizedDescription": NSLocalizedString("Please try later.", comment:"")]) completion(DBError) } } }else{ print("Error : \(String(describing: error))") } }) I received the following error message: ?Error saving records: <CKError 0x600000bbe970: "Service Unavailable" (6/NSCocoaErrorDomain:4099); "Error connecting to CloudKit daemon. This could happen for many reasons, for example a daemon exit, a device reboot, a race with the connection inactivity monitor, invalid entitlements, and more. Check the logs around this time to investigate the cause of this error."; Retry after 5.0 seconds> baseNSError@0 NSError domain: "CKErrorDomain" - code: 6 _userInfo __NSDictionaryI * 4 key/value pairs 0x000060000349e300 [0] (null) "NSLocalizedDescription" : "Error connecting to CloudKit daemon. This could happen for many reasons, for example a daemon exit, a device reboot, a race with the connection inactivity monitor, invalid entitlements, and more. Check the logs around this time to investigate the cause of this error." key __NSCFConstantString * "NSLocalizedDescription" 0x00000001117155a0 value __NSCFConstantString * "Error connecting to CloudKit daemon. This could happen for many reasons, for example a daemon exit, a device reboot, a race with the connection inactivity monitor, invalid entitlements, and more. Check the logs around this time to investigate the cause of this error." 0x000000011057e700 [1] (null) "CKRetryAfter" : Int32(5) key __NSCFConstantString * "CKRetryAfter" 0x000000011057c680 value NSConstantIntegerNumber? Int32(5) 0x00000001105c2ed0 [2] (null) "CKErrorDescription" : "Error connecting to CloudKit daemon. This could happen for many reasons, for example a daemon exit, a device reboot, a race with the connection inactivity monitor, invalid entitlements, and more. Check the logs around this time to investigate the cause of this error." key __NSCFConstantString * "CKErrorDescription" 0x0000000110568d00 value __NSCFConstantString * "Error connecting to CloudKit daemon. This could happen for many reasons, for example a daemon exit, a device reboot, a race with the connection inactivity monitor, invalid entitlements, and more. Check the logs around this time to investigate the cause of this error." 0x000000011057e700 [3] (null) "NSUnderlyingError" : domain: "NSCocoaErrorDomain" - code: 4099 key __NSCFConstantString * "NSUnderlyingError" 0x0000000111715540 value NSError? domain: "NSCocoaErrorDomain" - code: 4099 0x00006000016cc300

I want to clear all the data in the zone, but I can't delete it. Below is my code, no logs are printed when running. static func clearData() { let coordinator = shared.container.persistentStoreCoordinator let fm = FileManager.default for d in shared.container.persistentStoreDescriptions { guard let url = d.url else { continue } do { if fm.fileExists(atPath: url.path()) { try coordinator.destroyPersistentStore(at: url, type: .sqlite) } } catch { logger.debug("Failed to delete db file, \(error)") } } for description in shared.container.persistentStoreDescriptions { guard let originalStoreURL = description.url else { continue } let walFileURL = originalStoreURL.deletingPathExtension().appendingPathExtension("sqlite-wal") let shmFileURL = originalStoreURL.deletingPathExtension().appendingPathExtension("sqlite-shm") for url in [originalStoreURL, walFileURL, shmFileURL] { do { if fm.fileExists(atPath: url.path()) { try fm.removeItem(at: url) } } catch { logger.debug("Failed to delete db file, \(error)") } } } let container = CKContainer(identifier: appContainerID) container.privateCloudDatabase.fetchAllRecordZones { zones, error in if let error = error { print("Error fetching zones: ") } else if let zone = zones?.first, zone.zoneID.zoneName == "_defaultZone" { PersistenceController.shared.container.purgeObjectsAndRecordsInZone(with: zone.zoneID, in: nil) { ckShare, error in if let error = error { print("Error purge zones: \(error)") } if ckShare == nil { print("ckShare is nil") } } } } }

I've been trying to setup a successful migration, but it keeps failing with this error: NSCloudKitMirroringDelegate are not reusable and should have a lifecycle tied to a given instance of NSPersistentStore. I can't find any information about this online. I added breakpoints throughout the code in willMigrate, and it originally failed on this line: try? context.save() I removed that, and it still failed. After I reload the app, it doesn't run the migration again and the app loads successfully. I figured since it crashed, it would keep trying, but I guess not. Here's how my migration is setup. enum MigrationV1ToV2: SchemaMigrationPlan { static var schemas: [any VersionedSchema.Type] { [SchemaV1.self, SchemaV2.self] } static var stages: [MigrationStage] { [stage] } static let stage = MigrationStage.custom( fromVersion: SchemaV1.self, toVersion: SchemaV2.self, willMigrate: { context in // Get cycles let cycles = try? context.fetch(FetchDescriptor<SchemaV1.Cycle>()) if let cycles { for cycle in cycles { // Create new recurring objects based on what's in the cycle for income in cycle.income { let recurring = SchemaV2.Recurring(name: income.name, frequency: income.frequency, kind: .income) recurring.addAmount(.init(date: cycle.startDate, amount: income.amount)) context.insert(recurring) } for expense in cycle.expenses { let recurring = SchemaV2.Recurring(name: expense.name, frequency: expense.frequency, kind: .expense) recurring.addAmount(.init(date: cycle.startDate, amount: expense.amount)) context.insert(recurring) } for savings in cycle.savings { let recurring = SchemaV2.Recurring(name: savings.name, frequency: savings.frequency, kind: .savings) recurring.addAmount(.init(date: cycle.startDate, amount: savings.amount)) context.insert(recurring) } for investment in cycle.investments { let recurring = SchemaV2.Recurring(name: investment.name, frequency: investment.frequency, kind: .investment) recurring.addAmount(.init(date: cycle.startDate, amount: investment.amount)) context.insert(recurring) } } //try? context.save() } else { print("The cycles were not able to be fetched.") } }, didMigrate: { context in // Get new recurring objects let newRecurring = try? context.fetch(FetchDescriptor<SchemaV2.Recurring>()) if let newRecurring { for recurring in newRecurring { // Get all recurring with the same name and kind let sameName = newRecurring.filter({ $0.name == recurring.name && $0.kind == recurring.kind }) // Add amount history to recurring object, and then remove matching for match in sameName { recurring.amountHistory.append(contentsOf: match.amountHistory) context.delete(match) } } //try? context.save() } else { print("The new recurring objects could not be fetched.") } } ) } Here's is my modelContainer in the app file. There is a fatal error occurring here that's crashing the app. var sharedModelContainer: ModelContainer = { let schema = Schema(versionedSchema: SchemaV2.self) let modelConfiguration = ModelConfiguration(schema: schema, isStoredInMemoryOnly: false) do { return try ModelContainer( for: schema, migrationPlan: MigrationV1ToV2.self, configurations: [modelConfiguration] ) } catch { fatalError("Could not create ModelContainer: \(error)") } }() Does anyone have any suggestions for this? EDIT: I found this error in the console that may be relevant. BUG IN CLIENT OF CLOUDKIT: Registering a handler for a CKScheduler activity identifier that has already been registered (com.apple.coredata.cloudkit.activity.export.8F7A1261-4324-40B4-B041-886DF36FBF0A). CloudKit setup failed because it couldn't register a handler for the export activity. There is another instance of this persistent store actively syncing with CloudKit in this process. And here is the fatal error Fatal error: Could not create ModelContainer: SwiftDataError(_error: SwiftData.SwiftDataError._Error.loadIssueModelContainer, _explanation: nil)

struct ModelContainerSetup { static let shared = ModelContainerSetup() private static let containerIdentifier = "iCloud.Journal" func setupModelContainer() -> ModelContainer { let schema = Schema([User.self]) let modelConfiguration = ModelConfiguration( schema: schema, isStoredInMemoryOnly: false, cloudKitDatabase: .private(Self.containerIdentifier) ) do { return try ModelContainer(for: schema, configurations: [modelConfiguration]) } catch { fatalError("Could not create ModelContainer: \(error)") } } **Expected Behavior: ** When CloudKit storage is full, the app should continue functioning with local storage Data should persist locally even if cloud sync fails Sync should resume when storage becomes available **Actual Behavior: ** ModelContainer initialization fails completely Local data also stops getting saved **Environment: ** iOS 17.0+ SwiftData Private CloudKit database Ideal Behaviour: When iCloud fails, the data should still be saved locally. I do not want to have two different containers so that I can maintain data consistency.

I created 2 different schemas, and made a small change to one of them. I added a property to the model called "version". To see if the migration went through, I setup the migration plan to set version to "1.1.0" in willMigrate. In the didMigrate, I looped through the new version of Tags to check if version was set, and if not, set it. I did this incase the willMigrate didn't do what it was supposed to. The app built and ran successfully, but version was not set in the Tag I created in the app. Here's the migration: enum MigrationPlanV2: SchemaMigrationPlan { static var schemas: [any VersionedSchema.Type] { [DataSchemaV1.self, DataSchemaV2.self] } static let stage1 = MigrationStage.custom( fromVersion: DataSchemaV1.self, toVersion: DataSchemaV2.self, willMigrate: { context in let oldTags = try? context.fetch(FetchDescriptor<DataSchemaV1.Tag>()) for old in oldTags ?? [] { let new = Tag(name: old.name, version: "Version 1.1.0") context.delete(old) context.insert(new) } try? context.save() }, didMigrate: { context in let newTags = try? context.fetch(FetchDescriptor<DataSchemaV2.Tag>()) for tag in newTags ?? []{ if tag.version == nil { tag.version = "1.1.0" } } } ) static var stages: [MigrationStage] { [stage1] } } Here's the model container: var sharedModelContainer: ModelContainer = { let schema = Schema(versionedSchema: DataSchemaV2.self) let modelConfiguration = ModelConfiguration(schema: schema, isStoredInMemoryOnly: false) do { return try ModelContainer( for: schema, migrationPlan: MigrationPlanV2.self, configurations: [modelConfiguration]) } catch { fatalError("Could not create ModelContainer: \(error)") } }() I ran a similar test prior to this, and got the same result. It's like the code in my willMigrate isn't running. I also had print statements in there that I never saw printed to the console. I tried to check the CloudKit console for any information, but I'm having issues with that as well (separate post). Anyways, how can I confirm that my migration was successful here?

I previously got this error when I used a PassKey to log in. I'm not using that. I've put my password in multiple times, closed the browser, etc. It doesn't seem to be working. The only thing I can think is that because my Mac is using a different iCloud account, it's not letting me. Does anyone have any ideas?

Hey folks, I'm having an issue where iCloud sync is only working in the Development environment, not on Prod. I have deployed the schema to Prod through the CloudKit console, although I did it after the app went live on the AppStore. Even though the two schema are identical, iCloud sync just doesn't work on Prod. Things I tried on the code side: Initially I did the most basic SwiftData+CloudKit setup: var modelContainer: ModelContainer { let schema = Schema([Book.self, Goal.self]) let config = ModelConfiguration(isStoredInMemoryOnly: false, cloudKitDatabase: doesUserSyncToiCloud ? .automatic : .none) var container: ModelContainer do { container = try ModelContainer(for: schema, configurations: config) } catch { fatalError() } return container } var body: some Scene { WindowGroup { AnimatedSplashScreen { MainTabView() } } .modelContainer(modelContainer) } This is enough to make iCloud sync work at the Development level. Then when I noticed the issues on Prod I did some digging and found this on the Docs (https://developer.apple.com/documentation/swiftdata/syncing-model-data-across-a-persons-devices): let config = ModelConfiguration() 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.com.example.Trips") desc.cloudKitContainerOptions = opts // Load the store synchronously so it completes before initializing the // CloudKit schema. desc.shouldAddStoreAsynchronously = false if let mom = NSManagedObjectModel.makeManagedObjectModel(for: [Trip.self, Accommodation.self]) { let container = NSPersistentCloudKitContainer(name: "Trips", 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: Trip.self, Accommodation.self, configurations: config) } catch { fatalError(error.localizedDescription) } I've no idea why Apple would include this CoreData setup in a SwiftData documentation, but I went ahead and adapted it to my code as well. I see now that some new "assets" were added to my Development schema, but I'm afraid to deploy these changes to Prod, since I'm not even confident that this CoreData setup is necessary in a SwiftData app. Does anyone have any thoughts on this? Have you run into similar issues? Any help would be much appreciated; thanks!

I've realized that I need to use migration plans, but those required versioned schemas. I think I've updated mine, but I wanted to confirm if this was the proper procedure. To start, none of my models were versioned. I've since wrapped them in a VersionedSchema like this: enum TagV1: VersionedSchema { static var versionIdentifier: Schema.Version = .init(1, 0, 0) static var models: [any PersistentModel.Type] { [Tag.self] } @Model final class Tag { var id = UUID() var name: String = "" // Relationships var transactions: [Transaction]? = nil init(name: String) { self.name = name } } } I also created a type alias to point to this. typealias Tag = TagV1.Tag This is what my container looks like in my app file. var sharedModelContainer: ModelContainer = { let schema = Schema([ Tag.self ]) let modelConfiguration = ModelConfiguration(schema: schema, isStoredInMemoryOnly: false) do { return try ModelContainer(for: schema, configurations: [modelConfiguration]) } catch { fatalError("Could not create ModelContainer: \(error)") } }() The application builds and run successfully. Does this mean that my models are successfully versioned now? I'm trying to avoid an error I came across in earlier testing. That occurred because none of my models were versioned and I tried to setup a migration plan Cannot use staged migration with an unknown coordinator model version.

Is it possible to reset SwiftData to a state identical to that of a newly installed app? I have experienced some migration issues where, when I add a new model, I need to reinstall the entire application for the ModelContainer creation to work. Deleting all existing models does not seem to make any difference. A potential solution I currently have, which appears to work but feels quite hacky, is as follows: let _ = try! ModelContainer() modelContainer = try! ModelContainer(for: Student.self, ...) This seems to force out this error CoreData: error: Error: Persistent History (66) has to be truncated due to the following entities being removed: (...) which seems to reset SwiftData. Any other suggestions?

I have an app that uses SwiftData with CloudKit to synchronize data across a users devices. I'm able to replicate data created on one device on another and when removing data, it is also removed on the other device. So, I know that SwiftData and CloudKit are configured correctly. What I'd like to do though, is to ensure that if a user installs the app on an additional device, that the data is synchronized upon app start. When testing my app on a third device, via TestFlight, there was no data in the app upon launch even though all three devices are using the same Apple account (e.g. Apple ID). What is the best way to achieve this?

I'm trying to add Cloud Kit integration to SwiftData app (that is already in the App Store, btw). When the app is installed on devices that are directly connected to Xcode, it works (a bit slow, but pretty well). But when the app is distributed to Testflight internal testers, the synchronization doesn't happen at all. So, is this situation normal and how can I test apps with iCloud integration properly?