I'm a first time developer for Swift, (getting on a bit!) but after programming in VB back in the late 90s I wanted to write an app for iPhone. I think I might have gone about it the wrong way, but I've got an app that works great on my iPhone or works great on my iPad. It saves the data persistently on device, but, no matter how much I try, what I read and even resorting to AI (ChatGPT & Gemini) I still can't get it to save the data on iCloud to synchronise between the two and work across the devices. I think it must be something pretty fundamental I'm doing (or more likely not doing) that is causing the issue. I'm setting up my signing and capabilities as per the available instructions but I always get a fatal error. I think it might be something to do with making fields optional, but at this point I'm second guessing myself and feeling a complete failure. Any advice or pointers would be really gratefully appreciated. I like my app and would like eventually to get it on the App Store but at this point in time I feel it should be on the failed projects heap! I've even tried a new Xcode project for iOS and asking it to use SwiftData and CloudKit - the default project should work - right? But it absolutely doesn't for me. Please send help!!

I have an Apple app that uses SwiftData and icloud to sync the App's data across users' devices. Everything is working well. However, I am facing the following issue: SwiftData does not support public sharing of the object graph with other users via iCloud. How can I overcome this limitation without stopping using SwiftData? Thanks in advance!

I'm trying to handle the serverRecordChanged return code you get in CKError when you have a conflict and your using the savePolicy of ifServerRecordUnchanged. According to the CKError.Code.serverRecordChanged documentation, I should be receiving all three records that I need to do a 3-way merge. The problem is that the ancestorRecord (CKRecordChangedErrorAncestorRecordKey can also be used to look it up in the userInfo) doesn't actually contain a record. It only contains the record metadata. Is there something I need to be doing to get the full ancestorRecord in the CKError? If not is it possible to query iCloud for the ancestorRecord? Given that iCloud has the change history (as I understand it), then it is theoretically possible. I just don't know how to do it if it is possible. Are 3-way merges even possible? The design of the serverRecordChanged looks like that is the intent, but I can't see how to do it with the data that CloudKit is providing.

I'm using NSPersistentCloudKitContainer to save, edit, and delete items, but it only works half of the time. When I delete an item and terminate the app and repoen, sometimes the item is still there and sometimes it isn't. The operations are simple enough: moc.delete(thing) try? moc.save() Here is my DataController. I'm happy to provide more info as needed class DataController: ObservableObject { let container: NSPersistentCloudKitContainer @Published var moc: NSManagedObjectContext init() { container = NSPersistentCloudKitContainer(name: "AppName") container.loadPersistentStores { description, error in if let error = error { print("Core Data failed to load: \(error.localizedDescription)") } } #if DEBUG do { try container.initializeCloudKitSchema(options: []) } catch { print("Error initializing CloudKit schema: \(error.localizedDescription)") } #endif moc = container.viewContext } }

Hi, I'm getting a very odd error log in my SwiftData setup for an iOS app. It is implemented to support schema migration. When starting the app, it simply prints the following log twice (seems to be dependent on how many migration steps, I have two steps in my sample code): CoreData: error: Attempting to retrieve an NSManagedObjectModel version checksum while the model is still editable. This may result in an unstable verison checksum. Add model to NSPersistentStoreCoordinator and try again. (Yes there is a mistyped word "verison", this is exactly the log) The code actually fully works. But I have neither CloudKit configured, nor is this app in Production yet. I'm still just developing. Here is the setup and code to reproduce the issue. Development mac version: macOS 15.5 XCode version: 16.4 iOS Simulator version: 18.5 Real iPhone version: 18.5 Project name: SwiftDataDebugApp SwiftDataDebugApp.swift: import SwiftUI import SwiftData @main struct SwiftDataDebugApp: App { var sharedModelContainer: ModelContainer = { let schema = Schema([ Item.self, ]) let modelConfiguration = ModelConfiguration(schema: schema, isStoredInMemoryOnly: false, allowsSave: true) do { return try ModelContainer(for: schema, migrationPlan: ModelMigraitonPlan.self, configurations: [modelConfiguration]) } catch { fatalError("Could not create ModelContainer: \(error)") } }() var body: some Scene { WindowGroup { ContentView() } .modelContainer(sharedModelContainer) } } Item.swift: import Foundation import SwiftData typealias Item = ModelSchemaV2_0_0.Item enum ModelSchemaV1_0_0: VersionedSchema { static var versionIdentifier = Schema.Version(1, 0, 0) static var models: [any PersistentModel.Type] { [Item.self] } @Model final class Item { var timestamp: Date init(timestamp: Date) { self.timestamp = timestamp } } } enum ModelSchemaV2_0_0: 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 tags: [Tag] = [] init(timestamp: Date, tags: [Tag]) { self.timestamp = timestamp self.tags = tags } } } enum ModelMigraitonPlan: SchemaMigrationPlan { static var schemas: [any VersionedSchema.Type] { [ModelSchemaV1_0_0.self] } static var stages: [MigrationStage] { [migrationV1_0_0toV2_0_0] } static let migrationV1_0_0toV2_0_0 = MigrationStage.custom( fromVersion: ModelSchemaV1_0_0.self, toVersion: ModelSchemaV2_0_0.self, willMigrate: nil, didMigrate: { context in let items = try context.fetch(FetchDescriptor<ModelSchemaV2_0_0.Item>()) for item in items { item.tags = Array(repeating: "abc", count: Int.random(in: 0...3)).map({ Tag(value: $0) }) } try context.save() } ) } Tag.swift: import Foundation struct Tag: Codable, Hashable, Comparable { var value: String init(value: String) { self.value = value } static func < (lhs: Tag, rhs: Tag) -> Bool { return lhs.value < rhs.value } static func == (lhs: Tag, rhs: Tag) -> Bool { return lhs.value == rhs.value } func hash(into hasher: inout Hasher) { hasher.combine(value) } } ContentView.swift: import SwiftUI import SwiftData struct ContentView: View { @Environment(\.modelContext) private var modelContext @Query private var items: [Item] var body: some View { VStack { List { ForEach(items) { item in VStack(alignment: .leading) { Text(item.timestamp, format: Date.FormatStyle(date: .numeric, time: .standard)) HStack { ForEach(item.tags, id: \.hashValue) { tag in Text("\(tag.value)") } } } } .onDelete(perform: deleteItems) } Button("Add") { addItem() } .padding(.top) } } private func addItem() { withAnimation { let newItem = Item(timestamp: Date(), tags: [Tag(value: "Hi")]) modelContext.insert(newItem) } do { try modelContext.save() } catch { print("Error saving add: \(error.localizedDescription)") } } private func deleteItems(offsets: IndexSet) { withAnimation { for index in offsets { modelContext.delete(items[index]) } } do { try modelContext.save() } catch { print("Error saving delete: \(error.localizedDescription)") } } } #Preview { ContentView() .modelContainer(for: Item.self, inMemory: true) } I hope someone can help, couldn't find anything related to this log at all.

The NSPersistentCloudKitContainer synchronization between core data and iCloud was working fine with phone 15.1. Connected a new iPhone iOS 15.5, it gives error: CoreData: debug: CoreData+CloudKit: -[NSCloudKitMirroringDelegate managedObjectContextSaved:](2504): <NSCloudKitMirroringDelegate: 0x28198c000>: Observed context save: <NSPersistentStoreCoordinator: 0x2809c9420> - <NSManagedObjectContext: 0x2819ad520> 2022-12-05 13:32:28.377000-0600 r2nr[340:6373] [error] error: CoreData+CloudKit: -[NSCloudKitMirroringDelegate _importFinishedWithResult:importer:](1245): <PFCloudKitImporter: 0x2837dd740>: Import failed with error: Error Domain=NSCocoaErrorDomain Code=4864 "*** -[NSKeyedUnarchiver _initForReadingFromData:error:throwLegacyExceptions:]: incomprehensible archive (0x53, 0x6f, 0x6d, 0x65, 0x20, 0x65, 0x78, 0x61)" UserInfo={NSDebugDescription=*** -[NSKeyedUnarchiver _initForReadingFromData:error:throwLegacyExceptions:]: incomprehensible archive (0x53, 0x6f, 0x6d, 0x65, 0x20, 0x65, 0x78, 0x61)} CoreData: error: CoreData+CloudKit: -[NSCloudKitMirroringDelegate _importFinishedWithResult:importer:](1245): <PFCloudKitImporter: 0x2837dd740>: Import failed with error: Error Domain=NSCocoaErrorDomain Code=4864 "*** -[NSKeyedUnarchiver _initForReadingFromData:error:throwLegacyExceptions:]: incomprehensible archive (0x53, 0x6f, 0x6d, 0x65, 0x20, 0x65, 0x78, 0x61)" UserInfo={NSDebugDescription=*** -[NSKeyedUnarchiver _initForReadingFromData:error:throwLegacyExceptions:]: incomprehensible archive (0x53, 0x6f, 0x6d, 0x65, 0x20, 0x65, 0x78, 0x61)} I go back and try with my old iPhone iOS 15.1, gives same error.

I have transitioned to CKSyncEngine for syncing data to iCloud, and it is working quite well. I have a question regarding best practices for modifying and saving a CKRecord which already exists in the private or shared database. In my current app, most CKRecords will never be modified after saving to the database, so I do not persist a received record locally after updating my local data model. In the rare event that the local data for that record is modified, I manually fetch the associated server record from the database, modify it, and then use CKSyncEngine to save the modified record. As an alternative method, I can create a new CKRecord locally with the corresponding recordID and the modified data, and then use CKSyncEngine to attempt to save that record to the database. Doing so generates an error in the delegate method handleSentRecordZoneChanges, where I receive the local record I tried to save back inevent.failedRecordSaves with a .serverRecordChanged error, along with the corresponding server CKRecord. I can then update that server record with the local data and re-save using CKSyncEngine. I have not yet seen any issues when doing it this way. The advantage of the latter method is that CKSyncEngine handles the entire database operation, eliminating the manual fetch step. My question is: is this an acceptable practice, or could this result in other unforeseen issues?

LSUB always returns all the subscribed folders. For example lsub "" "test/*" returns a list of all the folders and not just subscribed folders that are subfolders of test. I.e, it returns the same folder list as lsub "" "*". For more details please see https://bugzilla.mozilla.org/show_bug.cgi?id=1817707#c15

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)

I've noticed several crashes that look like they're caused by an index out of bound in internal methods of NSFetchedResultsController. This happens while changes are merged from the persistent store container into the view context. Here's an example of the last exception backtrace. Exactly which internal methods that are called in - [NSFetchedResultsController(PrivateMethods) _core_managedObjectContextDidChange:] vary between crash reports but they all end up crashing from _NSArrayRaiseBoundException. The Core Data stack consists of one persistent store, one persistent store coordinator that the view context is set up to automatically merge changes from, and data is saved to disk from background context. persistentContainer.loadPersistentStores(...) viewContext = persistentContainer.viewContext viewContext.automaticallyMergesChangesFromParent = true backgroundContext = persistentContainer.newBackgroundContext() backgroundContext.mergePolicy = NSMergeByPropertyObjectTrumpMergePolicy backgroundClientContext = persistentContainer.newBackgroundContext() backgroundClientContext.mergePolicy = NSMergeByPropertyObjectTrumpMergePolicy Does anyone have any ideas what could be causing this? Thankful for any ideas or advice on how to investigate further.

Here’s the situation: • You’re downloading a huge list of data from iCloud. • You’re saving it one by one (sequentially) into SwiftData. • You don’t want the SwiftUI view to refresh until all the data is imported. • After all the import is finished, SwiftUI should show the new data. The Problem If you insert into the same ModelContext that SwiftUI’s @Environment(.modelContext) is watching, each insert may cause SwiftUI to start reloading immediately. That will make the UI feel slow, and glitchy, because SwiftUI will keep trying to re-render while you’re still importing. How to achieve this in Swift Data ?

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?

Hello Apple Team, We’re building a CloudKit-enabled Core Data app and would like clarification on the behavior and performance characteristics of Binary Data attributes with “Allows External Storage” enabled when used with NSPersistentCloudKitContainer. Initially, we tried storing image files manually on disk and only saving the metadata (file URLs, dimensions, etc.) in Core Data. While this approach reduced the size of the Core Data store, it introduced instability after app updates and broke sync between devices. We would prefer to use the official Apple-recommended method and have Core Data manage image storage and CloudKit syncing natively. Specifically, we’d appreciate guidance on the following: When a Binary Data attribute is marked as “Allows External Storage”, large image files are stored as separate files on device rather than inline in the SQLite store. How effective is this mechanism in keeping the Core Data store size small on device? Are there any recommended size thresholds or known limits for how many externally stored blobs can safely be managed this way? How are these externally stored files handled during CloudKit sync? Does each externally stored Binary Data attribute get mirrored to CloudKit as a CKAsset? Does external storage reduce the sync payload size or network usage, or is the full binary data still uploaded/downloaded as part of the CKAsset? Are there any bandwidth implications for users syncing via their private CloudKit database, versus developer costs in the public CloudKit database? Is there any difference in CloudKit or Core Data behavior when a Binary Data attribute is managed this way versus manually storing image URLs and handling the file separately on disk? Our goal is to store user-generated images efficiently and safely sync them via CloudKit, without incurring excessive local database bloat or CloudKit network overhead. Any detailed guidance or internal performance considerations would be greatly appreciated. Thank you, Paul Barry Founder & Lead Developer — Boat Buddy / Vessel Buddy iOS App Archipelago Environmental Solutions Inc.

Hi, I work on a financial app in Brazil and since Beta 1 we're getting several crashes. We already opened a code level support and a few feedback issues, but haven't got any updates on that yet. We were able to resolve some crashes changing some of our implementation but we aren't able to understand what might be happening with this last one. This is the log we got on console: erro 11:55:41.805875-0300 MyApp CoreData: error: Failed to load NSManagedObjectModel with URL 'file:///private/var/containers/Bundle/Application/0B9F47D9-9B83-4CFF-8202-3718097C92AE/MyApp.app/ServerDrivenModel.momd/' We double checked and the momd is inside the bundle. The same app works on any other iOS version and if we build using Xcode directly (without archiving and installing on an iOS26 device) it works as expected. Have anyone else faced a similar error? Any tips or advice on how we can try to solve that?

I have the following struct doing some simple tasks, running a network request and then saving items to Core Data. Per Xcode 26's new default settings (onisolated(nonsending) & defaultIsolation set to MainActor), the struct and its functions run on the main actor, which works fine and I can even safely omit the context.perform call because of it, which is great. struct DataHandler { func importGames(withIDs ids: [Int]) async throws { ... let context = PersistenceController.shared.container.viewContext for game in games { let newGame = GYGame(context: context) newGame.id = UUID() } try context.save() } } Now, I want to run this in a background thread to increase performance and responsiveness. So I followed this session (https://developer.apple.com/videos/play/wwdc2025/270) and believe the solution is to mark the struct as nonisolated and the function itself as @concurrent. The function now works on a background thread, but I receive a crash: _dispatch_assert_queue_fail. This happens whether I wrap the Core Data calls with context.perform or not. Alongside that I get a few new warnings which I have no idea how to work around. So, what am I doing wrong here? What's the correct way to solve this simple use case with Swift 6's new concurrency stuff and the default main actor isolation in Xcode 26? Curiously enough, when setting onisolated(nonsending) to false & defaultIsolation to non isolating, mimicking the previous behavior, the function works without crashing. nonisolated struct DataHandler { @concurrent func importGames(withIDs ids: [Int]) async throws { ... let context = await PersistenceController.shared.container.newBackgroundContext() for game in games { let newGame = GYGame(context: context) newGame.id = UUID() // Main actor-isolated property 'id' can not be mutated from a nonisolated context; this is an error in the Swift 6 language mode } try context.save() } }

I'm using NSPersistentCloudKitContainer with Core Data and I receive errors because my iCloud space is full. The errors printed are the following: <CKError 0x280df8e40: "Quota Exceeded" (25/2035); server message = "Quota exceeded"; op = 61846C533467A5DF; uuid = 6A144513-033F-42C2-9E27-693548EF2150; Retry after 342.0 seconds>. I want to inform the user about this issue, but I can't find a way to access the details of the error. I'm listening to NSPersistentCloudKitContainer.eventChangedNotification, I receive a error of type .partialFailure. But when I want to access the underlying errors, the partialErrorsByItemID property on the error is nil. How can I access this Quota Exceeded error? import Foundation import CloudKit import Combine import CoreData class SyncMonitor { fileprivate var subscriptions = Set<AnyCancellable>() init() { NotificationCenter.default.publisher(for: NSPersistentCloudKitContainer.eventChangedNotification) .sink { notification in if let cloudEvent = notification.userInfo?[NSPersistentCloudKitContainer.eventNotificationUserInfoKey] as? NSPersistentCloudKitContainer.Event { guard let ckerror = cloudEvent.error as? CKError else { return } print("Error: \(ckerror.localizedDescription)") if ckerror.code == .partialFailure { guard let errors = ckerror.partialErrorsByItemID else { return } for (_, error) in errors { if let currentError = error as? CKError { print(currentError.localizedDescription) } } } } } // end of sink .store(in: &subscriptions) } }

When a user first downloads my application they are prompted to sign into their apple account via a pop up. I have not had this pop up previously, I believe the change occurred after iOS18. I have functions that do a few things: Retrieves userRecordID Retrieves a userprofile(via userrecordid) from cloudkit.

I have a simple model @Model final class Movie: Identifiable { #Index\<Movie\>(\[.name\]) var id = UUID() var name: String var genre: String? init(name: String, genre: String?) { self.name = name self.genre = genre } } I turned on SQL debugging by including '-com.apple.CoreData.SQLDebug 3' argument on launch. When I fetch the data using the following code, it selects 3 records initially, but then also selects each record individually even though I am not referencing any other attributes. var fetchDescriptor = FetchDescriptor\<Movie\>() fetchDescriptor.propertiesToFetch = \[.id, .name\] fetchDescriptor.fetchLimit = 3 do { print("SELECT START") movies = try modelContext.fetch(fetchDescriptor) print("SELECT END") } catch { print("Failed to load Movie model.") } I see it selecting the 3 rows initially, but then it selects each one separately. Why would it do this on the initial fetch? I was hoping to select the data that I want to display and let the system select the entire record only when I access a variable that I did not initially fetch. CoreData: annotation: fetch using NSSQLiteStatement <0x600002158af0> on entity 'Movie' with sql text 'SELECT 1, t0.Z_PK, t0.ZID, t0.ZNAME FROM ZMOVIE t0 LIMIT 3' returned 3 rows with values: ( "<NSManagedObject: 0x600002158d70> (entity: Movie; id: 0xa583c7ed484691c1 <x-coredata://71E60F4C-1A40-4DB7-8CD1-CD76B4C11949/Movie/p1>; data: <fault>)", "<NSManagedObject: 0x600002158d20> (entity: Movie; id: 0xa583c7ed482691c1 <x-coredata://71E60F4C-1A40-4DB7-8CD1-CD76B4C11949/Movie/p2>; data: <fault>)", "<NSManagedObject: 0x600002158f00> (entity: Movie; id: 0xa583c7ed480691c1 <x-coredata://71E60F4C-1A40-4DB7-8CD1-CD76B4C11949/Movie/p3>; data: <fault>)" ) CoreData: annotation: fetch using NSSQLiteStatement <0x600002154d70> on entity 'Movie' with sql text 'SELECT 0, t0.Z_PK, t0.Z_OPT, t0.ZGENRE, t0.ZID, t0.ZNAME FROM ZMOVIE t0 WHERE t0.Z_PK = ? ' returned 1 rows CoreData: annotation: with values: ( "<NSSQLRow: 0x600000c89500>{Movie 1-1-1 genre=\"Horror\" id=4C5CB4EB-95D7-4DC8-B839-D4F2D2E96ED0 name=\"A000036\" and to-manys=0x0}" ) This all happens between the SELECT START and SELECT END print statements. Why is it fulfilling the faults immediately?

Hi All, I work on a cross platform app, iOS/macOS. All devises on iOS could synchronize data from Coredata : I create a client, I see him an all iOS devices. But when I test on macOs (with TestFlight) the Mac app could not get any information from iOs devices. On Mac, cloud drive is working because I could download and upload documents and share it between all devices, so the account is working but with my App on MacOS, there is no synchronisation. idea????

Hello Apple Team, We are looking at developing an iOS feature on our current development that stores user-generated images as CKAssets in the public CloudKit database, with access control enforced by our app’s own logic (not CloudKit Sharing as that has a limit of 100 shares per device). Each story or post is a public record, and users only see content based on buddy relationships handled within the app. We’d like to confirm that this pattern is consistent with Apple’s best practices for social features. Specifically: Is it acceptable to store user-uploaded CKAssets in the public CloudKit database, as long as access visibility is enforced by the app? Are there any performance or quota limitations (e.g., storage, bandwidth, or user sync limits) that apply to CKAssets in the public database when used at scale? Would CloudKit Sharing be recommended instead, even if we don’t require user-to-user sharing invitations? For App Review, is this model (public CKAssets + app-enforced access control) compliant with Apple’s data and security expectations? Are there any caching or bandwidth optimization guidelines for handling image-heavy public CKAsset data in CloudKit? Thanks again for your time