Greetings my fellow engineers, I use SwiftData in my iOS app. The schema is unversioned and consists of a single model. I've been modifying the model for almost two years now and relying on automatic database migrations. I had no problems for all that time, but now trying to add a property to the model or even remove a property from the model results in an error which seems like SwiftData is no longer capable of performing an automatic migration. The log console has things like the following: CoreData: error: NSUnderlyingError : Error Domain=NSCocoaErrorDomain Code=134190 "(null)" UserInfo={reason=Each property must have a unique renaming identifier} CoreData: error: reason : Can't find or automatically infer mapping model for migration CoreData: error: storeType: SQLite CoreData: error: configuration: default CoreData: annotation: options: CoreData: annotation: NSMigratePersistentStoresAutomaticallyOption : 1 CoreData: annotation: NSInferMappingModelAutomaticallyOption : 1 CoreData: annotation: NSPersistentStoreRemoteChangeNotificationOptionKey : 1 CoreData: annotation: NSPersistentHistoryTrackingKey : 1 CoreData: error: <NSPersistentStoreCoordinator: 0x7547b5480>: Attempting recovery from error encountered during addPersistentStore: 0x753f8d800 Error Domain=NSCocoaErrorDomain Code=134140 "Persistent store migration failed, missing mapping model." Have you ever encountered such an issue? What are my options?

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 { ... }

I am trying to save to cloud kit shared database. The shared database does not allow zones to be set up. How do I save to sharedCloudDatabase without a zone? private func addItem(recordType: String, name: String) { let record = CKRecord(recordType: recordType) record[Constances.field.name] = name as CKRecordValue record[Constances.field.done] = false as CKRecordValue record[Constances.field.priority] = 0 as CKRecordValue CKContainer.default().sharedCloudDatabase.save(record) { [weak self] returnRecord, error in if let error = error { print("Error saving record: \(record[Constances.field.name] as? String ?? "No Name"): \n \(error)") return } } } The following error message prints out: Error saving record: Milk: &lt;CKError 0x15af87900: "Server Rejected Request" (15/2027); server message = "Default zone is not accessible in shared DB"; op = B085F7BA703D4A08; uuid = 87AEFB09-4386-4E43-81D7-971AAE8BA9E0; container ID = "iCloud.com.sfw-consulting.Family-List"&gt;

Hi, I am building an iOS app with SwiftUI and SwiftData for the first time and I am experiencing a lot of difficulty with this error: Thread 44: Fatal error: Never access a full future backing data - PersistentIdentifier(id: SwiftData.PersistentIdentifier.ID(backing: SwiftData.PersistentIdentifier.PersistentIdentifierBacking.managedObjectID(<ID> <x-coredata://<UUID>/MySwiftDataModel/p1>)), backing: SwiftData.PersistentIdentifier.PersistentIdentifierBacking.managedObjectID(<ID> <x-coredata://<UUID>/MySwiftDataModel/p1>)) with Optional(<UUID>) I have been trying to figure out what the problem is, but unfortunately I cannot find any information in the documentation or on other sources online. My only theory about this error is that it is somehow related to fetching an entity that has been created in-memory, but not yet saved to the modelContext in SwiftData. However, when I am trying to debug this, it's not clear this is the case. Sometimes the error happens, sometimes it doesn't. Saving manually does not always solve the error. Therefore, it would be extremely helpful if someone could explain what this error means and whether there are any best practices to do with SwiftData, or some pitfalls to avoid (such as wrapping my model context into a repository class). To be clear, this problem is NOT related to one area of my code, it happens throughout my app, at unpredictable places and time. Given that there is very little information related to this error, I am at a loss at how to make sure that this never happens. This question has been asked on the forum here as well as on StackOverflow, Reddit (can't link that here), but none of the answers worked for me. For reference, my models generally look like this: import Foundation import SwiftData @Model final class MySwiftDataModel { // Stable cross-device identity @Attribute(.unique) var uuid: UUID var someNumber: Int var someString: String @Relationship(deleteRule: .nullify, inverse: \AnotherSwiftDataModel.parentModel) var childModels: [AnotherSwiftDataModel] init(uuid: UUID = UUID(), someNumber: Int = 1, someString: String = "Some", childModels: [AnotherSwiftDataModel] = []) { self.uuid = uuid self.someNumber = someNumber self.someString = someString self.childModels = childModels } func addChildModel(model: AnotherSwiftDataModel) { self.childModels.append(model) } func removeChildModel(by id: PersistentIdentifier) { self.childModels = self.childModels.filter { $0.id != id } } } and the child model: import Foundation import SwiftData @Model final class AnotherSwiftDataModel { // Stable cross-device identity @Attribute(.unique) var uuid: UUID var someNumber: Int var someString: String var parentModel: MySwiftDataModel? init(uuid: UUID = UUID(), someNumber: Int = 1, someString: String = "Some") { self.uuid = uuid self.someNumber = someNumber self.someString = someString } } For now, you can assume I am not using CloudKit - i know for a fact the error is unrelated to CloudKit, because it happens when I am not using CloudKit (so I do not need to follow CloudKit's requirements for model design, such as nullable values etc). As I said, the error surfaces at different times - sometimes during assignments, a lot of times during deletions of related models, etc. Could you please explain what I am doing wrong and how I can make sure that this error does not happen? What are the architectural patterns that work best for SwiftData in this case? Do you have any examples of things I should avoid? Thanks

Hello, the last days I was trying to solve a bug in my Unit Tests related to the CoreData "NSManagedObjectContextObjectsDidChange" Notification. Im using some kind of Notification handler to save and abstract that for the UI and while the tests are running this notification was triggered with objects that doesn't exists anymore, which has resulted in a crash. After some debugging I have detected, that the objects in here are really old. The objects here was from few tests ago, where a Merge Conflict happened. In the meantime there was a plenty of resets and deletes of the whole db. I have also seen that the bad notification is the first in the stack trace of the main thread, which is in my opinion also not usual. So the real question is: The only difference what I have found for the bad notification to the real notification, was the existence of the key "NSObjectsChangedByMergeChangesKey" in the UserInfo dictionary of the ObjectsDidChange Notification. But this key is nowhere found in the documentation of Apple. Also the search engines does not produce any result. So what is this key and when is this key contained in this notification and when not? Maybe if I understand this, it helps me to understand the overall issue ...

We’re using a private database with a custom zone. Record types and related schema are created programmatically rather than through the dashboard. When running the app in the development environment, I can see that data is saved and can be retrieved successfully. However, in the iCloud console, I don’t see any record types or even the custom zone. Additionally, I’m unable to deploy any schema to production because no changes are detected. Do you have any ideas on what we might be missing? Installing the app from TestFlight when trying to upload a record CloudKit reports this error: <CKError 0x13f40bb10: "Invalid Arguments" (12/2006); server message = "Cannot create new type MyType in production schema" ...>

I am trying out the new AttributedString binding with SwiftUI’s TextEditor in iOS26. I need to save this to a Core Data database. Core Data has no AttributedString type, so I set the type of the field to “Transformable”, give it a custom class of NSAttributedString, and set the transformer to NSSecureUnarchiveFromData When I try to save, I first convert the Swift AttributedString to NSAttributedString, and then save the context. Unfortunately I get this error when saving the context, and the save isn't persisted: CoreData: error: SQLCore dispatchRequest: exception handling request: <NSSQLSaveChangesRequestContext: 0x600003721140> , <shared NSSecureUnarchiveFromData transformer> threw while encoding a value. with userInfo of (null) Here's the code that tries to save the attributed string: struct AttributedDetailView: View { @ObservedObject var item: Item @State private var notesText = AttributedString() var body: some View { VStack { TextEditor(text: $notesText) .padding() .onChange(of: notesText) { item.attributedString = NSAttributedString(notesText) } } .onAppear { if let nsattributed = item.attributedString { notesText = AttributedString(nsattributed) } else { notesText = "" } } .task { item.attributedString = NSAttributedString(notesText) do { try item.managedObjectContext?.save() } catch { print("core data save error = \(error)") } } } } This is the attribute setup in the Core Data model editor: Is there a workaround for this? I filed FB17943846 if someone can take a look. Thanks.

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?

I’m trying to build a CRUD app using SwiftData, @Query model and multidatepicker. The data from a multidatepicker is stored or persists in SwiftData as Set = []. My current dilemma is how to use SwiftData and @Query model Predicate to find all records on the current date. I can’t find any SwiftData documentation or examples @Query using Set = []. My CRUD app should retrieve all records for the current date. Unfortunately, I don’t know the correct @Query model syntax for Set = [].

I'm developing an app that uses CloudKit synchronization with SwiftData and on visionOS I added an App Settings bundle. I have noticed that sometimes, when the app is open and the user changes a setting from the App Settings bundle, the following fatal error occurs: SwiftData/BackingData.swift:831: Fatal error: This model instance was destroyed by calling ModelContext.reset and is no longer usable. The setting is read within the App struct in the visionOS app target using @AppStorage and this value is in turn used to set the passthrough video dimming via the .preferredSurroundingsEffect modifier. The setting allows the user to specify the dimming level as dark, semi dark, or ultra dark. The fatal error appears to occur intermittently although the first time it was observed was after adding the settings bundle. As such, I suspect there is some connection between those code changes and this fatal error even though they do not directly relate to SwiftData.

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() } }

Hi all I have a problem with core data, where when a new user login that is different from the previous user i delete all of core data by using "destroyPersistentStore". Then i recreate the persistent store, this works when i am testing. When it does not work for one of my users when she test. I am not sure why this should not work, i have added the code i use to destroy the persistent store below. This code is run after login but before the view changes away from my login view. // Retrieves the shared `AppDelegate` instance guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else { return } appDelegate.destroyDataSyncBackground() // Get a reference to a NSPersistentStoreCoordinator let storeContainer = appDelegate.persistentContainer.persistentStoreCoordinator // Delete each existing persistent store for store in storeContainer.persistentStores { if let url = store.url { do { try storeContainer.destroyPersistentStore( at: url, ofType: store.type, options: nil ) } catch { print("Failed to deleted all") } } else { print("Failed to deleted all") } } // Re-create the persistent container appDelegate.persistentContainer = NSPersistentContainer( name: "CueToCue" // the name of // a .xcdatamodeld file ) // Calling loadPersistentStores will re-create the // persistent stores appDelegate.persistentContainer.loadPersistentStores { (store, error) in // Handle errors let description = NSPersistentStoreDescription() description.shouldMigrateStoreAutomatically = true description.shouldInferMappingModelAutomatically = true appDelegate.persistentContainer.persistentStoreDescriptions = [description] } // Reapply context configuration let viewContext = appDelegate.persistentContainer.viewContext viewContext.automaticallyMergesChangesFromParent = true viewContext.mergePolicy = NSMergeByPropertyObjectTrumpMergePolicy do { try viewContext.save() appDelegate.recreateDataSyncBackground() } catch { print("Debug: saving delete all failed.") } } The function "destroyDataSyncBackground" just set the my sync class to nil so stop any changes to core data while the code is running. The function "recreateDataSyncBackground" recreate the sync class so fetch, post and patch requests is made again.

Hi all, I recently discovered that I forgot to deploy my CloudKit schema changes from development to production - an oversight that unfortunately went unnoticed for 2.5 months. As a result, any data created during that time was never synced to iCloud and remains only in the local CoreData store. Once I pushed the schema to production, CloudKit resumed syncing new changes as expected. However, this leaves me with a gap: there's now a significant amount of data that would be lost if users delete or reinstall the app. Before I attempt to implement a manual backup or migration strategy, I was wondering: Does NSPersistentCloudKitContainer keep track of local changes that couldn't be synced doe to the missing schema and automatically reattempt syncing them now that the schema is live? If not, what would be the best approach to ensure this "orphaned" data gets saved to CloudKit retroactively. Thanks in advance for any guidance or suggestions.

Hi everyone, I’m facing an issue with CloudKit sync getting stuck during initial device migration in my SwiftData-based app. The app follows a local-first architecture using SwiftData + CloudKit sync, and works correctly for: ✔ Incremental sync ✔ Bi-directional updates ✔ Small datasets However, when onboarding a new device with large historical data, sync becomes extremely slow or appears stuck. Even after two hours data is not fully synced. ~6900 Transactions 🚨 Problem When installing the app on a new iPhone and enabling iCloud sync: • Initial hydration starts • A small amount of data syncs • Then sync stalls indefinitely Observed behaviour: • iPhone → Mac sync works (new changes sync back) • Mac → iPhone large historical migration gets stuck • Reinstalling app / clearing container does not resolve issue • Sync never completes full migration This gives the impression that: CloudKit is trickling data but not progressing after a certain threshold. The architecture is: • SwiftData local store • Manual CloudKit sync layer • Local-first persistence • Background push/pull sync So I understand: ✔ Conflict resolution is custom ✔ Initial import may not be optimized by default But I expected CloudKit to eventually deliver all records. Instead, the new device remains permanently in a “partial state”. ⸻ 🔍 Observations • No fatal CloudKit errors • No rate-limit errors • No quota issues • iCloud is available • Sync state remains “Ready” • Hydration remains “mostlyReady” Meaning: CloudKit does not report failure — but data transfer halts. ⸻ 🤔 Questions Would appreciate guidance on: Is CloudKit designed to support large initial dataset migration via manual sync layers? Or is this a known limitation vs NSPersistentCloudKitContainer? ⸻ Does CloudKit internally throttle historical record fetches? Could it silently stall without error when record volume is high? ⸻ Is there any recommended strategy for: • Bulk initial migration • Progressive hydration • Forcing forward sync progress ⸻ Should initial migration be handled outside CloudKit (e.g. via file transfer / backup restore) before enabling sync? ⸻ 🎯 Goal I want to support: • Large historical onboarding • Multi-device sync • User-visible progress Without forcing migration to Core Data. ⸻ 🙏 Any advice on: • Best practices • Debugging approach • CloudKit behavior in such scenarios would be greatly appreciated. Thank you!

We have an unreleased SwiftData app for iOS18+. While we were testing I saw reports on the forum about unexpected database migrations for codable arrays on iOS26.1. I'd like to ask a couple of questions: 1- Does this issue originate from the new Xcode version, or is it specific to iOS 26.1? 2- Is it possible to change our attribute so that users on older iOS versions receive the same model, preventing a migration from being triggered when they upgrade to iOS 26.1? One of our models looks like this: struct Point: Codable, Hashable { let x: Int let y: Int } @Model class Grid { private(set) var gridId: String = "" var points: [Point] = [] var updatedAt: Date = Date() private(set) var createdAt: Date = Date() #Index<Grid>([\.gridId]) ... } I can think of some options like: // 1 @Attribute(.transformable(by: CustomJsonTransformer.self)) var points: [Point] = [] // 2 @Attribute(.externalStorage) var points: [Point] = [] // 3 var points: Data = Data() // store points as data However, I'm not sure which one to use. What would you recommend to handle this, or is there a better strategy you would suggest?

I have the following code running on macOS and iOS: CKQuerySubscription *zsub = [[CKQuerySubscription alloc] initWithRecordType:ESS_CLOUDCONTROLLER_RECORDTYPE_PUSHNOTE predicate:[NSPredicate predicateWithFormat:@"TRUEPREDICATE"] subscriptionID:@"pushZSub" options:CKQuerySubscriptionOptionsFiresOnRecordUpdate|CKQuerySubscriptionOptionsFiresOnRecordCreation|CKQuerySubscriptionOptionsFiresOnRecordDeletion]; zsub.zoneID = zid; CKNotificationInfo *inf = [[CKNotificationInfo alloc] init]; inf.shouldSendContentAvailable = YES; inf.desiredKeys = @[ESS_PN_RECORDFIELD_KEY_OVERALLDATE]; zsub.notificationInfo = inf; CKModifySubscriptionsOperation *msop = [[CKModifySubscriptionsOperation alloc] initWithSubscriptionsToSave:@[zsub] subscriptionIDsToDelete:nil]; msop.qualityOfService = NSQualityOfServiceUserInitiated; msop.modifySubscriptionsCompletionBlock = ^(NSArray<CKSubscription *> * _Nullable savedSubscriptions, NSArray<CKSubscriptionID> * _Nullable deletedSubscriptionIDs, NSError * _Nullable operationError) { dispatch_async(dispatch_get_main_queue(), ^{ if (savedSubscriptions.count == 1) { //works also when already created. compH(YES, nil); } else { compH(NO, nil); } }); }; [self.database addOperation:msop]; (code synopsis: after i create a custom zone (not shown in code), I add a ckquerysubscription to it for a specific record type, configured as a silent notification) When I change the according record in my Mac app, I get an immediate silent push on iOS. On macOS, however, after I change the record in my iOS app, I don't get one. Sometimes, one silent push makes it through every now and then a minute+ late or so, and after that, it's going missing again. What's the deal? Everything's set up correctly (com.apple.developer.aps-environment is set, container-identifiers are the same, icloud services are the same, ubiquity-kvstore-identifier are the same). I obviously register for remote notifications in both apps. I see all the records and subscriptions and zones in both the Mac and iOS app. I tried setting alertBody to an empty string, or soundName to an empty string, or both to an empty string: no difference I tried having different subscriptions for my Mac and iOS app, since they use different bundle ids, but that was merged into one subscription server-side, so I'm thinking that's not it I tried making it not-silent by setting contentAvailable to NO and adding a full alertBody, title and subtitle. Again, worked on iOS, not on macOS. This has been going on since macOS 14 Sonoma (when I first got reports of this. Now running on macOS 26.3). Before Sonoma, it worked just fine. Now I thought perhaps it's because I had a subscription on the default zone, and not a custom one, so I tried subscribing to changes on a record in a custom zone (see code above), but that did not change anything either. It's all working fine, only the push notifications are not making it through to the Mac app. If I sudo killall apsd (kill the push service daemon), the last push notification suddenly miraculously makes it through, by the way. At this point, I'm out of ideas and would very much appreciate pointers as to how to debug this. Polling every 30 seconds for changes is so 1990s. Speaking of which, this is a rather long-time-running app (started in 2011). Could my CloudKit database be “too old” or “corrupted” or whatever? Thank you kindly, – Matthias

I would like to have a SwiftData predicate that filters against an array of PersistentIdentifiers. A trivial use case could filtering Posts by one or more Categories. This sounds like something that must be trivial to do. When doing the following, however: let categoryIds: [PersistentIdentifier] = categoryFilter.map { $0.id } let pred = #Predicate<Post> { if let catId = $0.category?.persistentModelID { return categoryIds.contains(catId) } else { return false } } The code compiles, but produces the following runtime exception (XCode 26 beta, iOS 26 simulator): 'NSInvalidArgumentException', reason: 'unimplemented SQL generation for predicate : (TERNARY(item != nil, item, nil) IN {}) (bad LHS)' Strangely, the same code works if the array to filter against is an array of a primitive type, e.g. String or Int. What is going wrong here and what could be a possible workaround?

In core-data I have a contact and location entity. I have one-to-many relationship from contact to locations and one-to-one from location to contact. I create contact in a seperate view and save it. Later I create a location, fetch the created contact, and save it while specifying the relationship between location and contact contact and test if it actually did it and it works. viewContext.perform { do { // Set relationship using the generated accessor method currentContact.addToLocations(location) try viewContext.save() print("Saved successfully. Locations count:", currentContact.locations?.count ?? 0) if let locs = currentContact.locations { print("📍 Contact has \(locs.count) locations.") for loc in locs { print("➡️ Location: \(String(describing: (loc as AnyObject).locationName ?? "Unnamed"))") } } } catch { print("Failed to save location: \(error.localizedDescription)") } } In my NSManagedObject class properties I have this : for Contact: @NSManaged public var locations: NSSet? for Location: @NSManaged public var contact: Contact? in my persistenceController I have: for desc in [publicStore, privateStore] { desc.setOption(true as NSNumber, forKey: NSPersistentStoreRemoteChangeNotificationPostOptionKey) desc.setOption(true as NSNumber, forKey: NSPersistentHistoryTrackingKey) desc.setOption(true as NSNumber, forKey: NSMigratePersistentStoresAutomaticallyOption) desc.setOption(true as NSNumber, forKey: NSInferMappingModelAutomaticallyOption) desc.setOption(true as NSNumber, forKey: "CKSyncCoreDataDebug") // Optional: Debug sync // Add these critical options for relationship sync desc.setOption(true as NSNumber, forKey: "NSPersistentStoreCloudKitEnforceRecordExistsKey") desc.setOption(true as NSNumber, forKey: "NSPersistentStoreCloudKitMaintainReferentialIntegrityKey") // Add this specific option to force schema update desc.setOption(true as NSNumber, forKey: "NSPersistentStoreRemoteStoreUseCloudKitSchemaKey") } When synchronization happens on CloudKit side, it creates CKRecords: CD_Contact and CD_Location. However for CD_Location it creates the relationship CD_contact as a string and references the CD_Contact. This I thought should have come as REFERENCE On the CD_Contact there is no CD_locations field at all. I do see the relationships being printed on coredata side but it does not come as REFERENCE on cloudkit. Spent over a day on this. Is this normal, what am I doing wrong here? Can someone advise?

Hi all, I have setup my app to use SwiftData with CloudKit sync. I have a production environment and development environment. I can reset the development environment for myself and all users in CloudKit console, but I can't reset the production one as it's tried to users' iCloud accounts, so I've added a button in-app for that feature. In the onboarding of my app, I pre-seed the DB with some default objects, which should be persisted between app install. The issue I'm running into is that I'm unable to force-pull these models from iCloud during the onboarding of a clean re-install, which leads to the models later appearing as duplicates once the user has been on the app for a few minutes and it has pulled from their iCloud account. If anyone has any suggestions on how to handle this issue, I would greatly appreciate it.

Trying to support undo & redo in an app that utilizes Swift Data and as with anything other than provided simplistic Apple demo examples the experience is not great. The problem: Im trying to build functionality that allows users to add items to an item group, where item and item group have a many-to-many relationship e.g. item group can hold many items and items can appear in multiple groups. When trying to do so with relatively simple setup of either adding or removing item group from items relationship array, I am pretty consistently met with a hard crash after performing undo & redo. Sometimes it works the first few undo & redos but 95% of the time would crash on the first one. Could not cast value of type 'Swift.Optional<Any>' (0x20a676be0) to 'Swift.Array<App.CodableStructModel>' (0x207a2bc08). Where CodableStructModel is a Codable Value type inside Item. Adding and removing this relationship should be undoable & redoable as typical for Mac interaction and is "supported" by SwiftData by default, meaning that the developer has to actively either wholly opt out of undo support in their modelContainer setup or do it on a per action scale with the only thing I know of: modelContext.processPendingChanges() modelContext.undoManager?.disableUndoRegistration() ..... modelContext.processPendingChanges() modelContext.undoManager?.enableUndoRegistration() General rant on SwiftData: Random crashes, inconsistencies, random cryptic errors thrown by the debugger and general lack of production level stability. Each update breaks something new and there is very little guidance and communication from the Swift Data team on how to adapt and more importantly consideration for developers that have adopted Swift Data. If SwiftData is not ready for production, it would go a long way to clearly communicate that and mark it as Beta product.