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?

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.

I am working on a software where we want to add the feature to share the whole database with the other user. Database is iCloud combined with coredata. The other user(s) should be able to edit /delete and even create new objects in the share. I did this with this code witch directly from sample code let participants = try await ckConainer.fetchParticipants(matching: [lookupInfo], into: selectedStore) for participant in participants { participant.permission = .readWrite participant.role = .privateUser share.addParticipant(participant) } try await ckConainer.persistUpdatedShare(share, in: selectedStore) the other user gets invited and I can see this in iCloud database that the other user is invited with status invited. but the other user never gets a mail or something to accept and join the share. How does the other needs to accept the invitation ?

One question I often see on DevForums and in my day DTS job is if a Core Data object managed by NSPersistentCloudKitContainer can be shared with other iCloud users. The answer is yes but you need to do it using CloudKit API directly because NSPersistentCloudKitContainer doesn’t support CloudKit shared database (CKContainer.sharedCloudDatabase) today. Assuming you have a Core Data object, let’s say a document, that you’d like to collaborate with your colleagues: You are the document owner and can use NSPersistentCloudKitContainer to fully manages the document and synchronize it across your devices. You can grab a CloudKit record associated with your document from NSPersistentCloudKitContainer using record(for:) or recordID(for:), and share it to your colleagues using UICloudSharingController. See our Sharing CloudKit Data with Other iCloud Users - https://developer.apple.com/documentation/cloudkit/sharing_cloudkit_data_with_other_icloud_users sample for how to share a CloudKit record. After accepting the sharing, your colleague, as a participant, can view or edit the shared document. The document resides in the participant’s CloudKit shared database and you have to manage it with your own code. When your colleague edits and saves the shared document, the changes go to the owner’s private database, and eventually synchronize to NSPersistentCloudKitContainer on the owner side.  As you can see, you need to implement #2 and #3 with your own code because NSPersistentCloudKitContainer can’t manage the data in the participant's shared database. If you have any difficulty after going through the above sample code, you can contact Apple’s DTS for help.

Using SwiftData and this is the simplest example I could boil down: @Model final class Item { var timestamp: Date var tag: Tag? init(timestamp: Date) { self.timestamp = timestamp } } @Model final class Tag { var timestamp: Date init(timestamp: Date) { self.timestamp = timestamp } } Notice Tag has no reference to Item. So if I create a bunch of items and set their Tag. Later on I add the ability to delete a Tag. Since I haven't added inverse relationship Item now references a tag that no longer exists so so I get these types of errors: SwiftData/BackingData.swift:875: Fatal error: This model instance was invalidated because its backing data could no longer be found the store. PersistentIdentifier(id: SwiftData.PersistentIdentifier.ID(url: x-coredata://EEC1D410-F87E-4F1F-B82D-8F2153A0B23C/Tag/p1), implementation: SwiftData.PersistentIdentifierImplementation) I think I understand now that I just need to add the item reference to Tag and SwiftData will nullify all Item references to that tag when a Tag is deleted. But, the damage is already done. How can I iterate through all Items that referenced a deleted tag and set them to nil or to a placeholder Tag? Or how can I catch that error and fix it when it comes up? The crash doesn't occur when loading an Item, only when accessing item.tag?.timestamp, in fact, item.tag?.id is still ok and doesn't crash since it doesn't have to load the backing data. I've tried things like just looping through all items and setting tag to nil, but saving the model context fails because somewhere in there it still tries to validate the old value. Thanks!

It takes a few seconds, sometimes a few minutes for records to be downloaded back from CloudKit when the user reinstalls the app, which leads users to thinking their data was lost. I would like to know if there’s any way to provide a visual feedback about the current CloudKit sync status so I can let users know their data is being in fact downloaded back to their devices.

I want to get to a point where I can use a small view with a query for my SwiftData model like this: @Query private var currentTrainingCycle: [TrainingCycle] init(/*currentDate: Date*/) { _currentTrainingCycle = Query(filter: #Predicate<TrainingCycle> { $0.numberOfDays > 0 // $0.startDate < currentDate && currentDate < $0.endDate }, sort: \.startDate) } The commented code is where I want to go. In this instance, it'd be created as a lazy var in a viewModel to have it stable (and not constantly re-creating the view). Since it was not working, I thought I could check the same view with a query that does not require any dynamic input. In this case, the numberOfDays never changes after instantiation. But still, each time the app tries to create this view, the app becomes unresponsive, the CPU usage goes at 196%, memory goes way high and the device heats up quickly. Am I holding it wrong? How can I have a dynamic predicate on a View in SwiftUI with SwiftData?

I work on an app that saves data to the Documents folder in the users iCloud Drive. This uses the iCloud -> iCloud Documents capability with a standard container. We've noticed an issue where a user will delete the apps data by doing to Settings > {Name} > iCloud > Storage > App Name > select "delete data from iCloud", and then our app can no longer write to or create the Documents folder. Once that happens, we get this error: Error Domain=NSCocoaErrorDomain Code=513 "You don't have permission to save the file "Documents" in the folder "iCloud~your~bundle~identifier"." UserInfo={NSFilePath=/private/var/mobile/Library/Mobile Documents/iCloud~your~bundle~identifier/Documents, NSURL=file:///private/var/mobile/Library/Mobile%20Documents/iCloud~your~bundle~identifier/Documents, NSUnderlyingError=0x1102c7ea0 {Error Domain=NSPOSIXErrorDomain Code=13 "Permission denied"}} This is reproducible using the sample project here https://developer.apple.com/documentation/uikit/synchronizing-documents-in-the-icloud-environment. Steps to reproduce in that project: Tap the plus sign in the top right corner to create a new document Add a document name and tap "Save to Documents" Go to Settings > {Name} > iCloud > Storage > SimpleiCloudDocument App Name > select "delete data from iCloud" Reopen the app and repeat steps 1-2 Observe error on MainViewController+Document.swift:59 Deleting and reinstalling the app doesn't seem to help.

According to my experiments SwiftData does not work with model attributes of primitive type UInt64. More precisely, it crashes in the getter of a UInt64 attribute invoked on an object fetched from the data store. With Core Data persistent UInt64 attributes are not a problem. Does anyone know whether SwiftData will ever support UInt64?

I've run into a strange issue. If a sheet loads a view that has a SwiftData @Query, and there is an if statement in the view body, I get the following error when running an iOS targetted SwiftUI app under MacOS 26.1: Set a .modelContext in view's environment to use Query While the view actually ends up loading the correct data, before it does, it ends up re-creating the sqlite store (opening as /dev/null). The strange thing is that this only happens if there is an if statement in the body. The statement need not ever evaluate true, but it causes the issue. Here's an example. It's based on the default xcode new iOS project w/ SwiftData: struct ContentView: View { @State private var isShowingSheet = false var body: some View { Button(action: { isShowingSheet.toggle() }) { Text("Show Sheet") } .sheet(isPresented: $isShowingSheet, onDismiss: didDismiss) { VStack { ContentSheetView() } } } func didDismiss() { } } struct ContentSheetView: View { @Environment(\.modelContext) private var modelContext @Query public var items: [Item] @State var fault: Bool = false var body: some View { VStack { if fault { Text("Fault!") } Button(action: addItem) { Label("Add Item", systemImage: "plus") } List { ForEach(items) { item in Text(item.timestamp, format: Date.FormatStyle(date: .numeric, time: .standard)) } } } } private func addItem() { withAnimation { let newItem = Item(timestamp: Date()) modelContext.insert(newItem) } } } It requires some data to be added to trigger, but after adding it and dismissing the sheet, opening up the sheet with trigger the Set a .modelContext in view's environment to use Query. Flipping on -com.apple.CoreData.SQLDebug 1 will show it trying to recreate the database. If you remove the if fault { Text("Fault!") } line, it goes away. It also doesn't appear to happen on iPhones or in the iPhone simulator. Explicitly passing modelContext to the ContentSheetView like ContentSheetView().modelContext(modelContext) also seems to fix it. Is this behavior expected?

I'm running a project with these settings: Default Actor Isolation: MainActor Approachable Concurrency: Yes Strict Concurrency Checking: Complete (this issue does not appear on the other two modes) I receive a warning for this very simple use case. Can I actually fix anything about this or is this a case of Core Data not being entirely ready for this? In reference to this, there was a workaround listed in the release notes of iOS 26 beta 5 (https://forums.swift.org/t/defaultisolation-mainactor-and-core-data-background-tasks/80569/22). Does this still apply as the only fix for this? This is a simplified sample meant to run on a background context. The issue obviously goes away if this function would just run on the MainActor, then I can remove the perform block entirely. class DataHandler { func createItem() async { let context = ... await context.perform { let newGame = Item(context: context) /// Main actor-isolated property 'timestamp' can not be mutated from a Sendable closure newGame.timestamp = Date.now // ... } } } The complete use case would be more like this: nonisolated struct DataHandler { @concurrent func saveItem() async throws { let context = await PersistenceController.shared.container.newBackgroundContext() try await context.perform { let newGame = Item(context: context) newGame.timestamp = Date.now try context.save() } } }

I'm using Swift Data for an app that requires iOS 18. All of my models conform to a protocol that guarantees they have a 'serverID' String variable. I wrote a function that would allow me to pass in a serverID String and have it fetch the model object that matched. Because I am lazy and don't like writing the same functions over and over, I used a Self reference so that all of my conforming models get this static function. Imagine my model is called "WhatsNew". Here's some code defining the protocol and the fetching function. protocol RemotelyFetchable: PersistentModel { var serverID: String { get } } extension WhatsNew: RemotelyFetchable {} extension RemotelyFetchable { static func fetchOne(withServerID identifier: String, inContext modelContext: ModelContext) -> Self? { var fetchDescriptor = FetchDescriptor<Self>() fetchDescriptor.predicate = #Predicate<Self> { $0.serverID == identifier } do { let allModels = try modelContext.fetch(fetchDescriptor) return allModels.first } catch { return nil } } } Worked great! Or so I thought... I built this and happily ran a debug build in the Simulator and on devices for months while developing the initial version but when I went to go do a release build for TestFlight, that build reliably crashed on every device with a message like this: SwiftData/DataUtilities.swift:65: Fatal error: Couldn't find \WhatsNew. on WhatsNew with fields [SwiftData.Schema.PropertyMetadata(name: "serverID", keypath: \WhatsNew., defaultValue: nil, metadata: Optional(Attribute - name: , options: [unique], valueType: Any, defaultValue: nil, hashModifier: nil)), SwiftData.Schema.PropertyMetadata(name: "title", keypath: \WhatsNew., defaultValue: nil, metadata: nil), SwiftData.Schema.PropertyMetadata(name: "bulletPoints", keypath: \WhatsNew.)>, defaultValue: nil, metadata: nil), SwiftData.Schema.PropertyMetadata(name: "dateDescription", keypath: \WhatsNew., defaultValue: nil, metadata: nil), SwiftData.Schema.PropertyMetadata(name: "readAt", keypath: \WhatsNew.)>, defaultValue: nil, metadata: nil)] It seems (cannot confirm) that something in the release build optimization process is stripping out some metadata / something about these models that makes this predicate crash. Tested on iOS 18.0 and 18.1 beta. How can I resolve this? I have two dozen types that conform to this protocol. I could manually specialize this function for every type myself but... ugh.

In a CloudKit private database, the Owner creates a custom zone and performs the following actions: Creates CKRecord1 with CKShare1 and invites Participant1 to it. Creates CKRecord2 with CKShare2 and invites Participant2 to it. Creates CKRecordShared, which should be accessible to both Participant1 and Participant2. How can I achieve step 3? I observed that: Setting a regular reference from CKRecord1 (or CKRecord2) to CKRecordShared does not automatically make CKRecordShared accessible to Participant1 (or Participant2). CKRecordShared can only have one parent, so it cannot be directly linked via parent reference to both Participant1 and Participant2 at the same time. One potential solution I see is to have the Owner create a separate CKShare for CKRecordShared and share it explicitly with each participant. However, this approach could lead to user errors, as it requires careful management of multiple shares for each participant. Is there a better way to handle this scenario, ensuring that CKRecordShared is accessible to multiple participants without introducing unnecessary complexity or potential errors?

Hi, I am creating (or trying to) my first app using SwiftData - and I have questions :-) The main question I can't get my head wrapped around is the following: Let's say I have the sample below... @Model class Person { @Relationship(inverse:\Hat.owner) var hat:Hat } @Model class Hat { var owner:Person? } It looks like I am creating a strong reference cycle between the person and the hat objects? And in fact I am seeing these kinds of reference cycles when I look at the memory debugger. Many code samples I have seen so far use this type of relationship declaration... And I am wondering: Am I missing something? Admittedly I don't find many discussions about memory leaks caused by SwiftData despite the syntax being used in many examples? So what is the situation? Did Apple just miss to explain that the inverse: declaration causes memory leaks or is there some kind of magic that I should understand?

If use a SortDescriptor for a model and sort by some attribute from a relationship, in DEBUG mode it all works fine and sorts. However, in release mode, it is an instant crash. SortDescriptor(.name, order: .reverse) ---- works SortDescriptor(.assignedUser?.name, order: .reverse) ---- works in debug but crash in release. What is the issue here, is it that SwiftData just incompetent to do this?

Is there a way to view the data saved when using swiftdata? Even after deleting all models, the storage space taken up by the app in Settings is too large.

I am attempting to migrate a cloudkit module that calls on manual cloudkit methods for fetching record zone changes, modifying records, etc to one that utilizes CKSyncEngine. I've got a basic implementation working with just a create method for one of my data models, however it seems like the sync engine keeps calling sync events on the same pending changes. Here is my current flow: The user will hit some button that lets them fill out a form to create a data model. The user saves the form. This triggers a method that takes the resulting data model and queues it to the sync engine's state (engine.state.add(pendingRecordZoneChanges: pendingChanges) I have my delegate method nextRecordZoneChangeBatch(_ context:...) implemented where it fetches the corresponding data model using the record ID and returns a batch containing the corresponding populated record from the data model. I have the handleEvent(_ event:...) delegate method implemented where I handle both .fetchRecordZoneChanges and .sentRecordZoneChanges. I have set up .sentRecordZoneChanges to merge the server record into my local record (and persisted locally) so that the record change tags are the same. After this last portion, it seems that the sync engine continues to keep pushing syncs/updates and I end up with numerous handleEvent(_ event:) calls that keep returning savedRecords (and occasionally failedRecordSaves). Am I missing some step to remove the record from the changes after the sync engine recognizes that I have properly saved the record to the server?

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?

I'm working on a macOS app with a Safari web extension. I'm trying to share a SwiftData model between devices using CloudKit synchronization. I am able to get synchronization in the main app on the same device, CloudKit sync works correctly — changes appear in the CloudKit Dashboard under com.apple.coredata.cloudkit.zone. However, in the Safari App Extension, data is saved locally and persists across launches, but never syncs to CloudKit. I have followed the recommended practices for configuring the App Group and entitlements, but the issue persists. Questions: Is there an official limitation preventing Safari App Extensions from connecting to the CloudKit daemon (cloudd)? If not, what entitlements or configuration changes are required for a Safari App Extension to successfully sync with CloudKit? Is the xpc_error=159 from bootstrap_look_up() a known sandbox restriction for this extension type? Any guidance from Apple engineers or others who have successfully used CloudKit from a Safari App Extension would be appreciated. What I’ve confirmed: The extension’s .entitlements includes: com.apple.security.app-sandbox com.apple.developer.icloud-services CloudKit com.apple.developer.icloud-container-identifiers iCloud.dev.example.myapp Same iCloud container ID for both app and extension CloudKit container exists and is initialized in CloudKit Console Running in :Sandbox environment during development Database name in SwiftData matches container identifier (without the iCloud. prefix) The extension’s codesign output shows correct entitlements App Group is configured (although in this case, extension and app use separate stores intentionally) Observed behavior in Console.app logs: CloudKit sync engine initializes in the extension XPC activities are registered for import/export: _xpc_activity_register: com.apple.coredata.cloudkit.activity.export. xpc_activity_set_criteria: ... import. Then a bootstrap lookup fails: failed to do a bootstrap look-up: xpc_error=[159: Unknown error: 159] CloudKit daemon connection error: CKErrorDomain Code=6 "Error connecting to CloudKit daemon" NSCocoaErrorDomain Code=4099 There is no “Will attempt to upload transactions” or “Upload succeeded” logs are ever seen. Symptoms When the extension is run, I see logs like the following in Console.app: [0x13e215820] failed to do a bootstrap look-up: xpc_error=[159: Unknown error: 159] CoreData+CloudKit: -[PFCloudKitSetupAssistant _checkAccountStatus:]_block_invoke(342): Fetched account info for store : (null) Error Domain=CKErrorDomain Code=6 "Error connecting to CloudKit daemon. This could happen for many reasons..."

SwiftData ModelContainer instances don't seem to have a value for setting the Data Protection class. Is the best way to set that by setting the Data Protection in the app capabilities? Is that the only way? I have a need for log data that would be "Complete unless open" and user data that would be "Complete", but how do I change one of the containers data protection class?