When running parallel Swift Testing tests that each create their own in-memory ModelContainer, the first xcodebuild test run succeeds but all subsequent runs fail with DefaultStore save failed validation errors — unless DerivedData is deleted between runs. Setup Each test suite creates an isolated in-memory container with a unique name: ModelConfiguration(UUID().uuidString, schema: schema, isStoredInMemoryOnly: true) The @Model class has non-optional properties (e.g. var v: String, var entityDicMoveNr: Int) that are always set in init. Symptoms on second run SwiftData.DefaultStore save failed with error: Error Domain=NSCocoaErrorDomain Code=1560 "Multiple validation errors occurred." NSValidationErrorKey=v, NSValidationErrorValue=null NSValidationErrorKey=entityDicMoveNr, NSValidationErrorValue=null NSValidationErrorKey=historyBackup, NSValidationErrorValue=null The errors appear before test code executes — during SwiftData's internal DefaultStore auto-save. Properties that are always initialized in Swift show as nil in the Core Data layer. What we verified Each run uses a fresh xctest process (different PIDs) Container creation succeeds (no errors in our ModelContainer init) The @Model init always sets all fields — confirmed with debug prints Deleting DerivedData before each run fixes it (but forces a full rebuild) What didn't help Using ModelContext(container) instead of container.mainContext Setting autosaveEnabled = false on both mainContext and custom contexts Using /dev/null URL instead of isStoredInMemoryOnly: true build-for-testing + test-without-building Clearing only Logs/Test or TestResults subdirectories Why not run via swift test? We can't fall back to swift test because our project uses RealityKit custom components, which silently fail to decode in CLI swift test. So xcodebuild test is our only option, making the DerivedData workaround especially costly. Workaround Delete DerivedData before each xcodebuild test invocation. Environment macOS 15.5, Xcode 16.4, Swift Testing with @Suite @MainActor parallel test suites. Question Is there a way to fully isolate in-memory ModelContainer instances so that no metadata leaks between xcodebuild test runs without requiring a full DerivedData clean?

Hi, Overview: I get the following error when trying to save / read from SwiftData It happens when I try to save color to SwiftData (code below) Error 'NSKeyedUnarchiveFromData' should not be used to for un-archiving and will be removed in a future release Questions How can I resolve the error? I am not directly using data, I am using just Float values, swift types. Why am I getting this error? Is there a way to add a breakpoint to stop at the exact type causing the error? (Symbolic breakpoint doesn't seem to help) Or is the below code ok and not responsible for the error? Code import SwiftUI nonisolated struct ColorRepresentation: Codable { let red: Float let green: Float let blue: Float let opacity: Float init(colorResolved: Color.Resolved) { red = colorResolved.red green = colorResolved.green blue = colorResolved.blue opacity = colorResolved.opacity } func color() throws -> Color { Color( red: Double(red), green: Double(green), blue: Double(blue), opacity: Double(opacity) ) } } extension ColorRepresentation: Equatable {}

Hello everyone, I've really been enjoying SwiftData's approach to handling DBs, however sharing data between users has caused me quite some headaches. I am currently developing an app for my local theatre that will help the assistant directors with production planning and would need a way to share data. On some big productions we have 2 ADs, so they'd need to be able to share the project and do collaborative work on it. I don't need fancy real-time editing or anything. However, SwiftData exposing an equivalent to Core Data’s NSPersistentCloudKitContainer sharing APIs for CKShare-based user-to-user collaboration would be amazing. As the only thing supported is per-user private data sync, I’m currently considering a hybrid approach until the full project could be shared: SwiftData for the main private app data a small separate Core Data + CloudKit sharing stack only for the shared timetables for cast and crew Is that the recommended implementation today, or is there a better SwiftData-friendly way to do this? I also filed Feedback Assistant request FB22712510 asking for native SwiftData support for user-to-user CloudKit sharing. Thanks for any pointers or help! Best regards, Aedan

Hi, Overview I have a SwiftData project which automatically syncs with CloudKit. When I run the app, I see the following error in Xcode logs. Error updating background task request: Error Domain=BGSystemTaskSchedulerErrorDomain Code=3 "(null)" My attempt I can enable Background processing (under Signing & Capabilities > Background modes), but I don't know the BGTaskSchedulerPermittedIdentifiers to add in the Info.plist Questions How can I resolve this? If I should enable background processing, what are the BGTaskSchedulerPermittedIdentifiers to add in Info.plist?

Hello, I've been trying the last week trying to get my app approved for the App Store. It's my first app and I'm not really sure what's going on. My app is getting rejected due to "App Completeness". Here's the rejection message: App Review Guideline Issue This is an automated message. The review of this submission cannot proceed. See below for more information. The app crashed after the initial launch. Apps that crash negatively impact users. Test the app on supported devices to identify and resolve crashes and stability issues before resubmitting for review. Learn more about testing a release build. When we submitted the first time we got rejected because our Apple sign in did not auto fill the user's name and we didn't have the EULA Link in the description. So the app didn't crash here as a tester sent screenshots and was in our app. We resubmitted and then we started getting these crashes. I examined the code we added from the first revision and tested the start up and everything worked fine on ours and our 30+ beta testers end. The thing is we're not getting a crash log from Apple testers or Apple's automated tester (if automated testing exists?). We are creating a fitness app that implements HealthKit. We have the required HealthShare and HealthUpdate messages in the signing and capabilities of our target. I'm not sure this would be the issue since the app actually executed the first run though. I've researched and some articles did say long load times on bad internet could make iOS terminate an app. So we worked to get our initial load network calls down from 10 seconds to about 1-2 seconds. This did not work either. We are using SwiftData to cache exercises fetched from our backend locally but we haven't made any changes to the entity's. So I wouldn't expect bad data to cause a crash especially because we flush even if it were bad data anyway. I've ran with instruments to see if this was a memory issue: With an Authed User with data loaded it gets to about 33MiB With a fresh install memory usage is about 17MiB I did have a point of interest in my profile: api.revenuecat.com is not listed in your app’s NSPrivacyTrackingDomain key in any privacy manifest. It may be following users across multiple apps and websites to create a profile about users of apps that contact this domain. I don't use revenue cat for tracking for Ads so I probably shouldn't add it to the NSPrivacyTrackingDomain right? I'm really lost here any advice would be much appreciated. I guess my questions are if Apple has an automating testing environment how can I closely match that for testing on my end? If this is an actual tester why am I not getting a crash log or steps to repeat this issue? Has anyone else experienced the pain I'm currently suffering?

I’m using SwiftData with CloudKit and running into an issue during initial sync on a fresh device. I’m importing a small set of records, some records has images as CKAsset (with about 5 images ~3MB). Records indexes are the default ones for the Dev env. The problem is that the import process never seems to complete. However, if I delete those records that contains the assets from the iCloud Dashboard, the import finishes successfully. Has anyone experienced something similar? What approach would you recommend to handle this without implementing a custom sync layer on top of CloudKit? I am logging remote changes events (NSPersistentStoreRemoteChange): CloudKit import in progress...|2026-04-25 22:18:10| Then I see: Background Task 49 ("CoreData: CloudKit Import"), was created over 30 seconds ago. In applications running in the background, this creates a risk of termination. Remember to call UIApplication.endBackgroundTask(_:) for your task in a timely manner to avoid this. And then the import never ends. Thanks!

Overview I'm developing a document-based app for macOS using SwiftData. When I undo/redo changes using Command-Z/Command-Shift-Z, the app reliably crashes with the following error: SwiftData/ModelSnapshot.swift:46: Fatal error: Unexpected backing data for snapshot creation: SwiftData._FullFutureBackingData<DocumentTest.ChildItem> And before the app crashes, what always happens is that UndoManager stops removing/restoring instances of ChildItem (but continues to remove/restore instances of ParentItem). The issue goes away when I enclose the relevant code in ModelContext.transaction(block:). However, this shouldn't be necessary, as ModelContext.autosaveEnabled is true by default. The issues are occurring with Xcode 26.4 (17E192) and macOS Tahoe 26.4 (25E246). I have modified the macOS Document App project template to showcase the issue. The sample project, along with a screen recording of the crash, can be downloaded from here: https://drive.google.com/drive/folders/13bCB1qRZ6273BI81zW2zUUBraSvv6p5w?usp=share_link Is this expected behavior or should I file a bug report in Feedback Assistant? Steps to Reproduce To recreate the issue, follow these steps: Download and extract the "Xcode Project.zip" file linked above. Open the extracted "DocumentTest" project in Xcode. Build and run the "DocumentTest" app. In the document selection window, click "New Document" at the bottom-left. In the app, click the "+" button at the top-right to add a ParentItem with ChildItems. Click on the added ParentItem's button to add another ChildItem to it. Repeat steps 5–6 until you have 5 ParentItems with an additional ChildItem. Press Command-Z 10 times to undo all the changes. Press Command-Shift-Z 10 times to redo all the changes. Repeat steps 8–9 until UndoManager stops removing/restoring the additional ChildItem, and continue repeating them until the app eventually crashes (you may have to repeat them 5–10 times before the issue occurs). If you uncomment the ModelContext.transaction(block:) at line 13 of ContentView.swift and repeat the same steps above, no ChildItems will go missing and the app will not crash. Code ParentItem Model @Model final class ParentItem { var timestamp: Date @Relationship( deleteRule: .cascade, inverse: \ChildItem.parentItem ) var childItems: [ChildItem] = [] init(timestamp: Date) { self.timestamp = timestamp } } ChildItem Model @Model final class ChildItem { var index: Int var parentItem: ParentItem? init(index: Int) { self.index = index } } Creating, Inserting, and Linking ParentItem and ChildItem // Create and insert ParentItem let newParentItem = ParentItem( timestamp: Date() ) modelContext.insert(newParentItem) // Create and insert ChildItems var newChildItems: [ChildItem] = [] for index in 0..<Int.random(in: 2...8) { let newChildItem = ChildItem(index: index) newChildItems.append(newChildItem) modelContext.insert(newChildItem) } /* Establish relationship between ParentItem and ChildItems */ for newChildItem in newChildItems { newParentItem.childItems.append( newChildItem ) newChildItem.parentItem = newParentItem } Adding an Additional ChildItem to ParentItem // Uncommenting this block fixes the crash // try! modelContext.transaction { // Create and insert the new ChildItem let newChildItem = ChildItem( index: parentItem.childItems.count ) modelContext.insert(newChildItem) // Establish relationship to parentItem parentItem.childItems.append(newChildItem) newChildItem.parentItem = parentItem // }

I am using SwiftData for my model. Until Xcode 15 beta 4 I did not have issues. Since beta 5 I am receiving the following red warning multiple times: 'NSKeyedUnarchiveFromData' should not be used to for un-archiving and will be removed in a future release This seems to be a CoreData warning. However, I am not using CoreData directly. I have no way to change the config of CoreData as used by SwiftData. My model just uses UUID, Int, String, Double, some of them as optionals or Arrays. I only use one attribute (.unique).

Overview I'm developing a document-based app for macOS using SwiftData. When I undo/redo changes using Command-Z/Command-Shift-Z, the app reliably crashes with the following error: SwiftData/ModelSnapshot.swift:46: Fatal error: Unexpected backing data for snapshot creation: SwiftData._FullFutureBackingData<DocumentTest.ChildItem> And before the app crashes, what always happens is that UndoManager stops removing/restoring instances of ChildItem (but continues to remove/restore instances of ParentItem). The issue goes away when I enclose the relevant code in ModelContext.transaction(block:). However, this shouldn't be necessary, as ModelContext.autosaveEnabled is true by default. The issues are occurring with Xcode 26.4 (17E192) and macOS Tahoe 26.4 (25E246). I have modified the macOS Document App project template to showcase the issue. The sample project, along with a screen recording of the crash, can be downloaded from here: https://drive.google.com/drive/folders/13bCB1qRZ6273BI81zW2zUUBraSvv6p5w?usp=share_link Is this expected behavior or should I file a bug report in Feedback Assistant? Steps to Reproduce To recreate the issue, follow these steps: Download and extract the "Xcode Project.zip" file linked above. Open the extracted "DocumentTest" project in Xcode. Build and run the "DocumentTest" app. In the document selection window, click "New Document" at the bottom-left. In the app, click the "+" button at the top-right to add a ParentItem with ChildItems. Click on the added ParentItem's button to add another ChildItem to it. Repeat steps 5–6 until you have 5 ParentItems with an additional ChildItem. Press Command-Z 10 times to undo all the changes. Press Command-Shift-Z 10 times to redo all the changes. Repeat steps 8–9 until UndoManager stops removing/restoring the additional ChildItem, and continue repeating them until the app eventually crashes (you may have to repeat them 5–10 times before the issue occurs). If you uncomment the ModelContext.transaction(block:) at line 13 of ContentView.swift and repeat the same steps above, no ChildItems will go missing and the app will not crash. Code ParentItem Model @Model final class ParentItem { var timestamp: Date @Relationship( deleteRule: .cascade, inverse: \ChildItem.parentItem ) var childItems: [ChildItem] = [] init(timestamp: Date) { self.timestamp = timestamp } } ChildItem Model @Model final class ChildItem { var index: Int var parentItem: ParentItem? init(index: Int) { self.index = index } } Creating, Inserting, and Linking ParentItem and ChildItem // Create and insert ParentItem let newParentItem = ParentItem( timestamp: Date() ) modelContext.insert(newParentItem) // Create and insert ChildItems var newChildItems: [ChildItem] = [] for index in 0..<Int.random(in: 2...8) { let newChildItem = ChildItem(index: index) newChildItems.append(newChildItem) modelContext.insert(newChildItem) } /* Establish relationship between ParentItem and ChildItems */ for newChildItem in newChildItems { newParentItem.childItems.append( newChildItem ) newChildItem.parentItem = newParentItem } Adding an Additional ChildItem to ParentItem // Uncommenting this block fixes the crash // try! modelContext.transaction { // Create and insert the new ChildItem let newChildItem = ChildItem( index: parentItem.childItems.count ) modelContext.insert(newChildItem) // Establish relationship to parentItem parentItem.childItems.append(newChildItem) newChildItem.parentItem = parentItem // }

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.

Overview I'm developing a document-based app for macOS using SwiftData. When I undo/redo changes using Command-Z/ Command-Shift-Z, the app randomly crashes with the following error: SwiftData/BackingData.swift:425: Fatal error: Failed to retrieve the identifier for \ChildItem.parentItem from KnownKeysDictionary:KnownKeysMap: ["parentItem": 2, "isModified": 1, "index": 0] values: [Optional(0), Optional(false), Optional(DocumentTest.ParentItem)] SwiftData._KKMDBackingData<DocumentTest.ChildItem> And sometimes, instead of the app crashing, my created @Model objects simply disappear. They do not reappear in the @Query on undo/redo. Both of these issues go away when I set modelContext.autosaveEnabled = false The issues are occurring with Xcode 26.4 (17E192) and macOS Tahoe 26.4 (25E246). I have modified the macOS Document App project template to showcase the issue. The project, along with a screen recording of the crash, can be downloaded from here: https://drive.google.com/drive/folders/1aDO34QleTm_rB9BuvVGjzzAP6jDXOc-o?usp=share_link Has anyone else experienced this? I'd like to know if this is a bug in the autosave feature of SwiftData and if I should file a bug report via Feedback Assistant. Steps to Reproduce To recreate the issue, follow these steps: Download and extract the "Xcode Project.zip" file linked above. Open the extracted "DocumentTest" project in Xcode. Build and run the "DocumentTest" app. In the document selection window, click "New Document" at the bottom-left. In the app, click the "+" button at the top-right to add a ParentItem with ChildItems. Click on the added ParentItem's button to modify one of its ChildItems. Repeat steps 5–6 until you have 5 ParentItems with a modified ChildItem. Press Command-Z 10 times to undo all the changes. Press Command-Shift-Z 10 times to redo all the changes. Repeat steps 8–9 until either the app crashes or some of the 5 ParentItems go missing in the list (you may have to repeat them 10–20 times before the issue occurs). If you change line 43 of ContentView.swift to modelContext.autosaveEnabled = false and repeat the same steps above, the app will not crash and no ParentItems will go missing. Code ParentItem Model @Model final class ParentItem { var timestamp: Date @Relationship( deleteRule: .cascade, inverse: \ChildItem.parentItem ) var childItems: [ChildItem] = [] init(timestamp: Date) { self.timestamp = timestamp } } ChildItem Model @Model final class ChildItem { var index: Int var isModified = false var parentItem: ParentItem? init(index: Int) { self.index = index } } Creating, Inserting, and Linking ParentItem and ChildItem // Create and insert ParentItem let newParentItem = ParentItem( timestamp: Date() ) modelContext.insert(newParentItem) // Create and insert ChildItems var newChildItems: [ChildItem] = [] for index in 0..<Int.random(in: 2...8) { let newChildItem = ChildItem(index: index) newChildItems.append(newChildItem) modelContext.insert(newChildItem) } /* Establish relationship between ParentItem and ChildItems */ newParentItem.childItems = newChildItems Modifying ChildItem let firstChildItem = parentItem.childItems .sorted(by: { $0.index < $1.index }).first if let firstChildItem, !firstChildItem.isModified { firstChildItem.isModified = true }

The production macOS build is showing severe performance problems, while Mac_Dev performs normally. Observed behavior in production Mac build: Issue board scrolling becomes inconsistent or nearly unusable Changing an issue status in detail view is very slow Scrolling the status menu/options can be slow Typing in issue description/notes fields becomes sluggish Dragging issues between milestones/statuses on the board can lag badly Observed behavior in Mac_Dev: Board scrolling is smooth Status changes are immediate Typing in description fields is responsive Drag/drop between milestones works well Important comparison: Mac_Dev appears to run against an isolated local SwiftData store Production Mac app uses the normal CloudKit-backed store Because the same UI is fast in Mac_Dev, this does not look like a pure rendering problem Most likely cause is production store / CloudKit sync churn amplifying existing SwiftUI invalidation and save behavior Current hypothesis: The production app is saving or observing live Issue mutations too aggressively Detail view edits and some quick actions may be causing repeated saves / broad view invalidation Cloud-backed persistence likely makes the problem much worse than the isolated dev store The UI architecture may still need cleanup, but the production data lane is likely a major factor Any help in understanding how best to address this would be helpful.

I have a FetchDescriptor that uses starts(with:) which works fine in debug builds but crashes in TestFlight and archive. For background information I'm using iCloud and model inheritance where the property being used in fetch descriptor is defined on the superclass, the fetch descriptor is for the subclass. Implementation: static func fetchDescriptor(nameStartingWith prefix: String) -> FetchDescriptor<ColorAsset> { let predicate = #Predicate<ColorAsset> { asset in asset.name.starts(with: prefix) } return FetchDescriptor<ColorAsset>(predicate: predicate) } @Model public class Asset: Identifiable { // MARK: - Properties var name: String = "" .... } @available(macOS 26.0, *) @Model public class ColorAsset: Asset { ... }

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

I'm building a SwiftUI app with SwiftData and want to centralize both query logic and related actions in a manager class. For example, let's say I have a reading app where I need to track the currently reading book across multiple views. What I want to achieve: @Observable class ReadingManager { let modelContext: ModelContext // Ideally, I'd love to do this: @Query(filter: #Predicate<Book> { $0.isCurrentlyReading }) var currentBooks: [Book] // ❌ But @Query doesn't work here var currentBook: Book? { currentBooks.first } func startReading(_ book: Book) { // Stop current book if any if let current = currentBook { current.isCurrentlyReading = false } book.isCurrentlyReading = true try? modelContext.save() } func stopReading() { currentBook?.isCurrentlyReading = false try? modelContext.save() } } // Then use it cleanly in any view: struct BookRow: View { @Environment(ReadingManager.self) var manager let book: Book var body: some View { Text(book.title) Button("Start Reading") { manager.startReading(book) } if manager.currentBook == book { Text("Currently Reading") } } } The problem is @Query only works in SwiftUI views. Without the manager, I'd need to duplicate the same query in every view just to call these common actions. Is there a recommended pattern for this? Or should I just accept query duplication across views as the intended SwiftUI/SwiftData approach?

I encountered an error when trying to rollback context after deleting some model with multiple one-to-many relationships when encountered a problem later in a deleting method and before saving the changes. Something like this: do { // Fetch model modelContext.delete(model) // Do some async work that potentially throws try modelContext.save() } catch { modelContext.rollback() } When relationship is empty - the parent has no children - I can safely delete and rollback with no issues. However, when there is even one child when I call even this code: modelContext.delete(someModel) modelContext.rollback() I'm getting a fatal error: SwiftData/ModelSnapshot.swift:46: Fatal error: Unexpected backing data for snapshot creation: SwiftData._FullFutureBackingData<ChildModel> I use ModelContext from within the ModelActor but using mainContext changes nothing. My ModelContainer is quite simple and problem occurs on both in-memory and persistent storage, with or without CloudKit database being enabled. I can isolate the issue in test environment, so the model that's being deleted (or any other) is not being accessed by any other part of the application. However, problem looks the same in the real app. I also changed the target version of iOS from 18.0 to 26.0, but to no avail. My models look kind of like this: @Model final class ParentModel { var name: String @Relationship(deleteRule: .cascade, inverse: \ChildModel.parent) var children: [ChildModel]? init(name: String) { self.name = name } } @Model final class ChildModel { var name: String @Relationship(deleteRule: .nullify) var parent: ParentModel? init(name: String) { self.name = name } } I tried many approaches that didn't help: Fetching all children (via fetch) just to "populate" the context Accessing all children on parent model (via let _ = parentModel.children?.count) Deleting all children reading models from parent: for child in parentModel.children ?? [] { modelContext.delete(child) } Deleting all children like this: let parentPersistentModelID = parentModel.persistentModelID modelContext.delete(model: ChildModel.self, where: #Predicate { $0.parent.persistentModelID == parentPersistentModelID }, includeSubclasses: true) Removing @Relationship(deleteRule: .nullify) from ChildModel relationship definition I found 2 solution for the problem: To manually fetch and delete all children prior to deleting parent: let parentPersistentModelID = parentModel.persistentModelID for child in try modelContext.fetch(FetchDescriptor<ChildModel>(predicate: #Predicate { $0.parent.persistentModelID == parentPersistentModelID })) { modelContext.delete(child) } modelContext.delete(parentModel) Trying to run my code in child context (let childContext = ModelContext(modelContext.container)) All that sounds to me like a problem deep inside Swift Data itself. The first solution I found, fetching potentially hundreds of child models just to delete them in case I might need to rollback changes on some error, sounds like awful waste of resources to me. The second one however seems to work fine has that drawback that I can't fully test my code. Right now I can wrap the context (literally creating class that holds ModelContext and calls its methods) and in tests for throwing methods force them to throw. By creating scratch ModelContext I loose that possibility. What might be the real issue here? Am I missing something?

I have two different VersionedSchema accessed via two different and distinct in-memory ModelContainers. However, both schemas have a model named Item. LocalSchema.Item and RemoteSchema.Item have slightly different properties. If I create and save RemoteSchema.Item in one context then I cannot create and save LocalSchema.Item in a different context due to missing origin property. enum LocalSchema: VersionedSchema { static var versionIdentifier: Schema.Version = .init(1, 0, 0) static var models: [any PersistentModel.Type] = [ Item.self ] @Model class Item { @Attribute(.unique) var title: String var created: Date var modified: Date init(title: String, created: Date, modified: Date) { self.title = title self.created = created self.modified = modified } } } enum RemoteSchema: VersionedSchema { static var versionIdentifier: Schema.Version = .init(1, 0, 0) static var models: [any PersistentModel.Type] = [ Item.self ] @Model class Item { var title: String var created: Date var modified: Date var origin: String init(title: String, created: Date, modified: Date, origin: String) { self.title = title self.created = created self.modified = modified self.origin = origin } } } In the above example, saving RemoteSchema.Item will cause LocalSchema.Item to fail. The error message I see is *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<NSManagedObject 0xa120f3750> setValue:forUndefinedKey:]: the entity Item is not key value coding-compliant for the key "origin".' Test Code @Test func createLocalItemWithManualSave() async throws { let context = ModelContext(try localStore()) let item = LocalSchema.Item(title: "local", created: .now, modified: .now) context.insert(item) try context.save() } @Test func createRemoteItemWithManualSave() async throws { let context = ModelContext(try remoteStore()) let item = RemoteSchema.Item(title: "remote", created: .now, modified: .now, origin: "from space") context.insert(item) try context.save() } func localStore() throws -> ModelContainer { let schema = Schema(versionedSchema: LocalSchema.self) let config = ModelConfiguration("local", schema: schema, isStoredInMemoryOnly: true, allowsSave: true, cloudKitDatabase: .none) return try ModelContainer(for: schema, configurations: config) } func remoteStore() throws -> ModelContainer { let schema = Schema(versionedSchema: RemoteSchema.self) let config = ModelConfiguration("remote", schema: schema, isStoredInMemoryOnly: true, allowsSave: true, cloudKitDatabase: .none) return try ModelContainer(for: schema, configurations: config) } I have created FB22310365

I've spent a few months writing an app that uses SwiftData with inheritance. Everything worked well until I tried adding CloudKit support. To do so, I had to make all relationships optional, which exposed what appears to be a bug. Note that this isn't a CloudKit issue -- it happens even when CloudKit is disabled -- but it's due to the requirement for optional relationships. In the code below, I get the following error on the second call to modelContext.save() when the button is clicked: Could not cast value of type 'SwiftData.PersistentIdentifier' (0x1ef510b68) to 'SimplePersistenceIdentifierTest.Computer' (0x1025884e0). I was surprised to find zero hit when Googling "Could not cast value of type 'SwiftData.PersistentIdentifier'". Some things to note: Calling teacher.computers?.append(computer) instead of computer.teacher = teacher results in the same error. It only happens when Teacher inherits Person. It only happens if modelContext.save() is called both times. It works if the first modelContext.save() is commented out. If the second modelContext.save()is commented out, the error occurs the second time the model context is saved (whether explicitly or implicitly). Keep in mind this is a super simple repro written to generate on demand the error I'm seeing in a normal app. In my app, modelContext.save() must be called in some places to update the UI immediately, sometimes resulting in the error seconds later when the model context is saved automatically. Not calling modelContext.save() doesn't appear to be an option. To be sure, I'm new to this ecosystem so I'd be thrilled if I've missed something obvious! Any thoughts are appreciated. import Foundation import SwiftData import SwiftUI struct ContentView: View { @Environment(\.modelContext) var modelContext var body: some View { VStack { Button("Do it") { let teacher = Teacher() let computer = Computer() modelContext.insert(teacher) modelContext.insert(computer) try! modelContext.save() computer.teacher = teacher try! modelContext.save() } } } } @Model class Computer { @Relationship(deleteRule: .nullify) var teacher: Teacher? init() {} } @Model class Person { init() {} } @available(iOS 26.0, macOS 26.0, *) @Model class Teacher: Person { @Relationship(deleteRule: .nullify, inverse: \Computer.teacher) public var computers: [Computer]? = [] override init() { super.init() } }

Hi Writing an app in Swift on Xcode for my iPhone, all software is the latest version. If after making a minor change and re-building all the application data has disappeared, is there a way to see if it is still in the .modelContainer and just not showing up?

Hey everyone, I found a possible SwiftData Release-only issue with nested sort descriptors on an optional relationship. In a minimal repro, sorting a @Query by a nested optional relationship key path like: SortDescriptor(\InvestigationPhotoAsset.imageAnalysis?.overallAestheticsScore, order: .reverse) works in Debug, but crashes at runtime in Release. The surprising part is that the crash depends on file layout: if the active SwiftData models and the sort logic are kept in the same Swift file, the app works if the same models are split into separate files, the Release build crashes, 'Debug' will also work The repro was reduced to just two SwiftData models: InvestigationPhotoAsset InvestigationImageAnalysis So this looks less like an app-modeling issue and more like a SwiftData/compiler/codegen issue related to nested sort metadata in optimized builds. If useful, I can also give you a slightly more formal version with a title and code snippet block. Please check out the code example here Has anyone faced something similar? Bug is reported as FB22173905