I have an app which uses ubiquitous containers and files in them to share data between devices. It's a bit unusual in that it indexes files in directories the user grants access to, which may or may not exist on a second device - those files are identified by SHA-1 hash. So a second device scanning before iCloud data has fully sync'd can create duplicate references which lead to an unpleasant user experience. To solve this, I store a small binary index in the root of the ubiquitous file container of the shared data, containing all of the known hashes, and as the user proceeds through the onboarding process, a background thread is attempting to "prime" the ubiquitous container by calling FileManager.default.startDownloadingUbiquitousItemAt() for each expected folder and file in a sane order. This likely creates a situation not anticipated by the iOS/iCloud integration's design, as it means my app has a sort of precognition of files it should not yet know about. In the common case, it works, but there is a corner case where iCloud sync has just begun, and very, very little metadata is available (the common case, however, in an emulator), in which two issues come up: I/O may hang indefinitely, trying to read a file as it is arriving. This one I can work around by running the I/O in a thread created with the POSIX pthread_create and using pthread_cancel to kill it after a timeout. Attempts to call FileManager.default.startDownloadingUbiquitousItemAt() fails with an error Error Domain=NSCocoaErrorDomain Code=257 "The file couldn’t be opened because you don’t have permission to view it.". The permissions aspect of it is nonsense, but I can believe there's no applicable "sort of exists, sort of doesn't" error code to use and someone punted. The problem is that this same error will be thrown on any attempt to access that file for the life of the application - a restart is required to make it usable. Clearly, the error or the hallucinated permission failure is cached somewhere in the bowels of iOS's FileManager. I was hoping startAccessingSecurityScopedResource() would allow me to bypass such a cache, as it does with URL.resourceValues() returning stale file sizes and last modified times. But it does not. Is there some way to clear this state without popping up a UI with an Exit button (not exactly the desired iOS user experience)?

I have developed an podcast app, where subscriped podcast & episodes synched with iCloud. So its working fine with iOS & iPad with latest os version, but iCloud not synching in iPod with version 15. Please help me to fix this. Thanks Devendra K.

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

Hi, I did cloudkit synchronization using swiftdata. However, synchronization does not occur automatically, and synchronization occurs intermittently only when the device is closed and opened. For confirmation, after changing the data in Device 1 (saving), when the data is fetched from Device 2, there is no change. I've heard that there's still an issue with swiftdata sync and Apple is currently troubleshooting it, is the phenomenon I'm experiencing in the current version normal?

What have people's experience with converting locally stored app data to a more browser based accessible format? Firebase seems expensive, Subabase a bit more challenging, and CloudKit too restrictive.

SwiftData crashes 100% when fetching history of a model that contains an optional codable property that's updated: SwiftData/Schema.swift:389: Fatal error: Failed to materialize a keypath for someCodableID.someID from CrashModel. It is possible that this path traverses a type that does not work with append(), please file a bug report with a test. Would really appreciate some help or even a workaround. Code: import Foundation import SwiftData import Testing struct VaultsSwiftDataKnownIssuesTests { @Test func testCodableCrashInHistoryFetch() async throws { let container = try ModelContainer( for: CrashModel.self, configurations: .init( isStoredInMemoryOnly: true ) ) let context = ModelContext(container) try SimpleHistoryChecker.hasLocalHistoryChanges(context: context) // 1: insert a new value and save let model = CrashModel() model.someCodableID = SomeCodableID(someID: "testid1") context.insert(model) try context.save() // 2: check history it's fine. try SimpleHistoryChecker.hasLocalHistoryChanges(context: context) // 3: update the inserted value before then save model.someCodableID = SomeCodableID(someID: "testid2") try context.save() // The next check will always crash on fetchHistory with this error: /* SwiftData/Schema.swift:389: Fatal error: Failed to materialize a keypath for someCodableID.someID from CrashModel. It is possible that this path traverses a type that does not work with append(), please file a bug report with a test. */ try SimpleHistoryChecker.hasLocalHistoryChanges(context: context) } } @Model final class CrashModel { // optional codable crashes. var someCodableID: SomeCodableID? // these actually work: //var someCodableID: SomeCodableID //var someCodableID: [SomeCodableID] init() {} } public struct SomeCodableID: Codable { public let someID: String } final class SimpleHistoryChecker { static func hasLocalHistoryChanges(context: ModelContext) throws { let descriptor = HistoryDescriptor<DefaultHistoryTransaction>() let history = try context.fetchHistory(descriptor) guard let last = history.last else { return } print(last) } }

I have a ModelActor that creates a hierarchy of models and returns a PersistentIdentifier for the root. I'd like to do that in a transaction, but I don't know of a good method of getting that identifier if the models are created in a transaction. For instance, an overly simple example: func createItem(timestamp: Date) throws -> PersistentIdentifier { try modelContext.transaction { let item = Item(timestamp: timestamp) modelContext.insert(item) } // how to return item.persistentModelID? } I can't return the item.persistentModelID from the transaction closure and even if I could, it will be a temporary ID until after the transaction is executed. I can't create the Item outside the transaction and just have the transaction do an insert because swift will raise a data race error if you then try to return item.persistentModelID. Is there any way to do this besides a modelContext.fetch* with separate unique identifiers?

Hello all Synopsis: document based SwiftData app breaks document handling after first save due to internal error saving the -shm file. Long: i am working on a small document based SwiftData app for macOS. The UI works well as long as the document was not saved. After saving the document and reopening it, I get an error consistently in console: BUG IN CLIENT OF libsqlite3.dylib: database integrity compromised by API violation: vnode unlinked while in use: /Users/vrunkel/Library/Containers/de.ecoobs.CurtailmentAnalyzer/Data/tmp/TemporaryItems/NSIRD_CurtailmentAnalyzer_mrXKMs/NewDocument/StoreContent-shm So somehow the -shm file is still referenced to NewDocument created when the app opens an untitled document and resides in the temporary folder. I have saved the document to my documents folder. After reopening and the above error deletion or addition of items crashes the app with a long backtrace to view updating: Modifications to the layout engine must not be performed from a background thread after it has been accessed from the main thread. I am not creating any threads or do background work. If I do not save the document but work within the new untitled document no problems occur. Even closing the app and reopening the untitled new doc (happens automatically) all is fine. To rule out any influence of my existing view structure I have created the most simple test case - Xcode -> New Project -> macOS document based app configured to use SwiftData. Same behaviour. After saving a new document the addition/deletion of items causes the thread-induced crash and shows the error in console when opening the document. I am using latest versions of Xcode 15.0 and macOS 14.0 Any ideas? thx, volker

Environment visionOS 26 Xcode 26 Issue I am experiencing crash when trying to access a [String] from a @Model data, after dismissing an immersiveSpace and opening a WindowGroup. This crash only occurs when trying to access the [String] property of my Model. It works fine with other properties. Thread 1: Fatal error: This backing data was detached from a context without resolving attribute faults: PersistentIdentifier(...) Steps to Reproduce Open WindowGroup Dismiss window, open ImmersiveSpace Dismiss ImmersiveSpace, reopen WindowGroup Any guidance would be appreciated! @main struct MyApp: App { var body: some Scene { WindowGroup(id: "main") { ContentView() } .modelContainer(for: [Item.self]) ImmersiveSpace(id: "immersive") { ImmersiveView() } } } // In SwiftData model @Model class Item { var title: String = "" // Accessing this property works fine var tags: [String] = [] @storageRestrictions(accesses: _$backingData, initializes: _tags) init(initialValue) { _$backingData.setValue(forKey: \. tags, to: initialValue) _tags =_ SwiftDataNoType() } get { _$observationRegistrar.access(self, keyPath: \.tags) **return self getValue(forkey: \.tags)** // Crashes here }

I'm using SwiftData with CloutKit with a very simple app. Data syncs between iOS, iPadOS, and visionOS, but not macOS. From what I can tell, macOS is never getting CK messages unless I'm running the app from Xcode. I can listen for the CK messages and show a line in a debug overlay. This works perfectly when I run from Xcode. I can see the notifications and see updates in my app. However, if I just launch the app outside of Xcode I will never see any changes or notifications. It is as if the Mac app never even tries to contact CloudKit. Schema has been deployed in the CloudKit console. The app is based on the multi-platform Xcode template. Again, only the macOS version has this issue. Is there some extra permission or setting I need to set up in order to use CloudKit on macOS? @State private var publisher = NotificationCenter.default.publisher(for: NSPersistentCloudKitContainer.eventChangedNotification).receive(on: DispatchQueue.main) .onReceive(publisher) { notification in // Listen for changes in CK events if let userInfo = notification.userInfo, let event = userInfo[NSPersistentCloudKitContainer.eventNotificationUserInfoKey] as? NSPersistentCloudKitContainer.Event { let message = "CloudKit Sync: \(event.type.rawValue) - \(event.succeeded ? "Success" : "Failed") - \(event.description)" // Store for UI display syncNotifications.append(message) if syncNotifications.count > 10 { syncNotifications.removeFirst() } } } .overlay(alignment: .topTrailing) { if !syncNotifications.isEmpty { VStack(alignment: .leading) { ForEach(syncNotifications, id: \.self) { notification in Text(notification) .padding(8) } } .frame(width: 800, height: 500) .cornerRadius(8) .background(Color.secondary.opacity(0.2)) .padding() .transition(.move(edge: .top)) } }

I have a UIKit app where I've adopted SwiftData and I'm struggling with a crash coming in from some of my users. I'm not able to reproduce it myself and as it only happens to a small fraction of my user base, it seems like a race condition of some sort. This is the assertion message: SwiftData/DefaultStore.swift:453: Fatal error: API Contract Violation: Editors must register their identifiers before invoking operations on this store SwiftData.DefaultStore: 00CF060A-291A-4E79-BEC3-E6A6B20F345E did not. (ID is unique per crash) This is the ModelActor that crashes: @available(iOS 17, *) @ModelActor actor ConsumptionDatabaseStorage: ConsumptionSessionStorage { struct Error: LocalizedError { var errorDescription: String? } private let sortDescriptor = [SortDescriptor(\SDConsumptionSession.startTimeUtc, order: .reverse)] static func createStorage(userId: String) throws -> ConsumptionDatabaseStorage { guard let appGroupContainer = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: UserDefaults.defaultAppGroupIdentifier) else { throw Error(errorDescription: "Invalid app group container ID") } func createModelContainer(databaseUrl: URL) throws -> ModelContainer { return try ModelContainer(for: SDConsumptionSession.self, SDPriceSegment.self, configurations: ModelConfiguration(url: databaseUrl)) } let databaseUrl = appGroupContainer.appendingPathComponent("\(userId).sqlite") do { return self.init(modelContainer: try createModelContainer(databaseUrl: databaseUrl)) } catch { // Creating the model storage failed. Remove the database file and try again. try? FileManager.default.removeItem(at: databaseUrl) return self.init(modelContainer: try createModelContainer(databaseUrl: databaseUrl)) } } func isStorageEmpty() async -> Bool { (try? self.modelContext.fetchCount(FetchDescriptor<SDConsumptionSession>())) ?? 0 == 0 // <-- Crash here! } func sessionsIn(interval: DateInterval) async throws -> [ConsumptionSession] { let fetchDescriptor = FetchDescriptor(predicate: #Predicate<SDConsumptionSession> { sdSession in if let startDate = sdSession.startTimeUtc { return interval.start <= startDate && interval.end > startDate } else { return false } }, sortBy: self.sortDescriptor) let consumptionSessions = try self.modelContext.fetch(fetchDescriptor) // <-- Crash here! return consumptionSessions.map { ConsumptionSession(swiftDataSession: $0) } } func updateSessions(sessions: [ConsumptionSession]) async throws { if #unavailable(iOS 18) { // Price segments are duplicated if re-inserted so unfortunately we have to delete and reinsert sessions. // On iOS 18, this is enforced by the #Unique macro on SDPriceSegment. let sessionIds = Set(sessions.map(\.id)) try self.modelContext.delete(model: SDConsumptionSession.self, where: #Predicate<SDConsumptionSession> { sessionIds.contains($0.id) }) } for session in sessions { self.modelContext.insert(SDConsumptionSession(consumptionSession: session)) } if self.modelContext.hasChanges { try self.modelContext.save() } } func deleteAllSessions() async { if #available(iOS 18, *) { try? self.modelContainer.erase() } else { self.modelContainer.deleteAllData() } } } The actor conforms to this protocol: protocol ConsumptionSessionStorage { func isStorageEmpty() async -> Bool func hasCreditCardSessions() async -> Bool func sessionsIn(interval: DateInterval) async throws -> [ConsumptionSession] func updateSessions(sessions: [ConsumptionSession]) async throws func deleteAllSessions() async } The crash is coming in from line 30 and 41, in other words, when trying to fetch data from the database. There doesn't seem to be any common trait for the crashes. They occur across iOS versions and device types. Any idea what might cause this?

For the past several days every time I log in to to the Cloudkit dashboard I get Error looking up Developer Teams, Please sign out and try again. No amount of singing out and back in changes anything.

I have some code which handles doing some computation on a background thread before updating Core Data NSManagedObjects by using the NSManagedObjectContext.perform functions. This code is covered in Sendable warnings in Xcode 26 (beta 6) because my NSManagedObject subclasses (autogenerated) are non-Sendable and NSManagedObjectContext.perform function takes a Sendable closure. But I can't really figure out what I should be doing. I realize this pattern is non-ideal for Swift concurrency, but it's what Core Data demands AFAIK. How do I deal with this? let moc = object.managedObjectContext! try await moc.perform { object.completed = true // Capture of 'object' with non-Sendable type 'MySpecialObject' in a '@Sendable' closure try moc.save() } Thanks in advance for your help!

I have the following lines of code to access data through CoreData. import Foundation import CoreData import CloudKit class CoreDataManager { static let instance = CoreDataManager() let container: NSPersistentCloudKitContainer let context: NSManagedObjectContext init() { container = NSPersistentCloudKitContainer(name: "ABC") container.loadPersistentStores(completionHandler: { (storeDescription, error) in if let error = error as NSError? { print(error.userInfo) } }) context = container.viewContext context.automaticallyMergesChangesFromParent = true context.mergePolicy = NSMergePolicy(merge: .mergeByPropertyObjectTrumpMergePolicyType) } func save() { do { try container.viewContext.save() print("Saved successfully") } catch { print("Error in saving data: \(error.localizedDescription)") } } } I have confirmed that I can share data between iPhone and iPad. Now, I need to use AppGroup as well. I have changed my code as follows. import Foundation import CoreData import CloudKit class CoreDataManager { static let shared = CoreDataManager() let container: NSPersistentContainer let context: NSManagedObjectContext init() { container = NSPersistentCloudKitContainer(name: "ABC") container.persistentStoreDescriptions = [NSPersistentStoreDescription(url: FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: "some group name")!.appendingPathComponent("CoreDataMama.sqlite"))] container.loadPersistentStores(completionHandler: { (description, error) in if let error = error as NSError? { print("Unresolved error \(error), \(error.userInfo)") } }) context = container.viewContext context.automaticallyMergesChangesFromParent = true context.mergePolicy = NSMergePolicy(merge: .mergeByPropertyObjectTrumpMergePolicyType) } func save() { do { try container.viewContext.save() print("Saved successfully") } catch { print("Error in saving data: \(error.localizedDescription)") } } } Other files being unaltered, my sample apps aren't sharing data. What am I doing wrong? Just FYI, I'm using actual devices. Thank you for your reading this topic.

Hi, I am currently experiencing some trouble when using parent model property in a predicate of a child model. I have an Item class that define parent-child relationship: @Model class Item { var timestamp: Date @Relationship(inverse: \Item.children) var parent: Item? var children: [Item] init(parent: Item? = nil, children: [Item] = [], timestamp: Date = .now) { self.parent = parent self.children = children self.timestamp = timestamp } } I subclass this model like that: @available(iOS 26, *) @Model final class CollectionItem: Item { /* ... */ } When i make a Query in my View like that the system crashes: @Query( filter: #Predicate<CollectionItem> { $0.parent == nil }, sort: \CollectionItem.name, ) private var collections: [CollectionItem] CrashReportError: Fatal Error in DataUtilities.swift AppName crashed due to fatalError in DataUtilities.swift at line 85. Couldn't find \CollectionItem.<computed 0x000000034005d4e8 (Optional<Item>)> on CollectionItem with fields [SwiftData.Schema.PropertyMetadata(name: "name", keypath: \CollectionItem.<computed 0x000000034003c120 (String)>, defaultValue: nil, metadata: nil), SwiftData.Schema.PropertyMetadata(name: "icon", keypath: \CollectionItem.<computed 0x000000034003ca04 (Optional<String>)>, defaultValue: nil, metadata: nil), SwiftData.Schema.PropertyMetadata(name: "timestamp", keypath: \Item.<computed 0x0000000340048018 (Date)>, defaultValue: nil, metadata: nil), SwiftData.Schema.PropertyMetadata(name: "parent", keypath: \Item.<computed 0x0000000340048a4c (Optional<Item>)>, defaultValue: nil, metadata: Optional(Relationship - name: , options: [], valueType: Any, destination: , inverseName: nil, inverseKeypath: Optional(\Item.<computed 0x0000000340048fe8 (Array<Item>)>))), SwiftData.Schema.PropertyMetadata(name: "children", keypath: \Item.<computed 0x0000000340048fe8 (Array<Item>)>, defaultValue: nil, metadata: nil)] When I query as Item it works but then i cannot sort on CollectionItem field and must add unnecessary down casting: @Query( filter: #Predicate<Item> { $0.parent == nil && $0 is CollectionItem }, ) private var items: [Item] Am I missing something? Is it a platform limitation or a known issue?

I'm building a macOS + iOS SwiftUI app using Xcode 14.1b3 on a Mac running macOS 13.b11. The app uses Core Data + CloudKit. With development builds, CloudKit integration works on the Mac app and the iOS app. Existing records are fetched from iCloud, and new records are uploaded to iCloud. Everybody's happy. With TestFlight builds, the iOS app has no problems. But CloudKit integration isn't working in the Mac app at all. No existing records are fetched, no new records are uploaded. In the Console, I see this message: error: CoreData+CloudKit: Failed to set up CloudKit integration for store: <NSSQLCore: 0x1324079e0> (URL: <local file url>) Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service named com.apple.cloudd was invalidated: failed at lookup with error 159 - Sandbox restriction." UserInfo={NSDebugDescription=The connection to service named com.apple.cloudd was invalidated: failed at lookup with error 159 - Sandbox restriction.} I thought it might be that I was missing the com.apple.security.network.client entitlement, but adding that didn't help. Any suggestions what I might be missing? (It's my first sandboxed Mac app, so it might be really obvious to anyone but me.)

hi, in my app, i have created and pushed CKRecords to the public database. others using the app have pushed CKRecords as well. is there any way i can query iCloud for "all the CKRecords that i created?" thanks, DMG

Hello there, I have a problem reaching the CloudKit dashboard. Every time I login, the login successes but then I get the error: An error has caused this web page to stop working correctly. This also happens when I click on the Button CloudKit dashboard. Then I can reload the page, but the same errors occurs again and again. Can someone help me with this problem? Thank you very much

If Cloudkit is enabled, SwiftData @Query operation hangs when the View scenePhase becomes active. Seems like the more @Query calls you have, the more it hangs. This has been first documented some time ago, but in typical Apple style, it has not been addressed or even commented on. https://developer.apple.com/forums/thread/761434

Hi everyone, I've recently implemented CKSyncEngine in my app, and I have two questions regarding its behavior: Duplicate FetchedRecordZoneChanges After Sending Changes: I’ve noticed that the engine sometimes receives a FetchedRecordZoneChanges event containing modifications and deletions that were just sent by the same device a few moments earlier. This event arrives after the SentRecordZoneChanges event, and both events share the same recordChangeTag, which results in double-handling the record. Is this expected behavior? I’d like to confirm if this is how CKSyncEngine works or if I might be overlooking something. Handling Initial Sync with a "Sync Screen": When a user opens the app for the first time and already has data stored in iCloud, I need to display a "Sync Screen" temporarily to prevent showing partial data or triggering abrupt, rapid UI changes. I’ve found that canceling current operations, then awaiting sendChanges() and fetchChanges() works well to ensure data is fully synced before dismissing the sync screen: displaySyncScreen = true await syncEngine.cancelOperations() try await syncEngine.sendChanges() try await syncEngine.fetchChanges() displaySyncScreen = false However, I’m unsure if canceling operations like this could lead to data loss or other issues. Is this a safe approach, or would you recommend a better strategy for handling this initial sync state?