What is the best way to switch between Core Data Persistent Stores? My use case is that I have a multi-user app that stores thousands of data items unique to each user. To me, having Persistent Stores for each user seems like the best design to keep their data separate and private. (If anyone believes that storing the data for all users in one Persistent Store is a better design, I'd appreciate hearing from them.) Customers might switch users 5 to 10 times a day. Switching users must be fast, say a second or two at most.

Hey guys, I'm developing a Swift app, using iCloud to store some data in Containers, and the new Containers I created are iCloud.com.xxx.dev . Therefore, there is a storage called dev in Settings -> icloud -> Manage Account Storage. Currently, the app is still under development and has not been released to the Appstore. My question: Settings -> icloud -> Manage Account Storage does not display my app name and icon, but only the suffix of the Containers id. Will this change after it is released to the Appstore? Are there any other control methods? Thank you

I’m running into a CloudKit sync issue that I can’t reconcile after multiple rebuilds, TestFlight uploads, and entitlement verification, and I’m hoping for guidance on what I’m missing or whether this is expected behavior. Context App: RankSpinnah Platforms: iOS + macOS Distribution: TestFlight Xcode: 26.x Both apps use the same bundle identifier, same container, and same Apple Developer team Automatic signing enabled; Xcode-managed profiles CloudKit capability enabled for both targets Both builds install and run correctly from TestFlight on: iPhone 17 Pro Apple-silicon Mac (M5 MacBook Pro) The Problem CloudKit data does not sync at all between devices. On both iOS and macOS, CloudKit queries return no records, and I consistently see this error: Field 'recordName' is not marked queryable This occurs even when querying for records that should exist and after fresh installs on both devices. What I’ve Verified Same iCloud account signed in on both devices CloudKit container exists and is enabled App Sandbox enabled with network access CloudKit entitlements present in the signed app (verified from the archived .app) TestFlight builds are using the correct container Rebuilt and re-uploaded after version bump (1.2.0 / build 2026.02.03) Both iOS and macOS apps successfully uploaded and installed via TestFlight Despite this, no data syncs, and the queryable error persists. What I’m Unsure About Whether recordName is expected to be non-queryable in production schemas Whether TestFlight + CloudKit requires an explicit production schema deploy beyond what Xcode manages Whether this indicates a schema mismatch between development and production environments Or whether something subtle changed in recent Xcode / CloudKit behavior Ask Can someone clarify: Whether querying by recordName should work in production CloudKit What specifically causes the “Field recordName is not marked queryable” error in TestFlight builds What steps are required to ensure CloudKit schemas are correctly deployed for cross-platform sync At this point I feel like I’m missing one critical step, but I can’t identify what it is. Thanks in advance for any guidance.

I'm using SwiftData with CloudKit private database. I was able to identify the error on my device by debugging in Xcode with com.apple.CoreData.SQLDebug flag. However, in Production, I couldn't find a way to get the cause of errors. I tried inspecting the error coming from eventChangedNotification. The NSPersistentCloudKitContainer.Event error does not contain any underlying error (neither CKError.userInfo nor in NSError.underlyingError). It only reports a partial failure with CKErrorDomain code 2. If a user encounter an error, there seems to be no way to retrieve the error details. Is there any way to access the error details or logs in Production?

If I set my build settings "default actor isolation" to MainActor, how do my @ModelActor actors and model classes need to look like ? For now, I am creating instances of my @ModelActor actors and passing my modelContext container and processing all data there. Everything stays in this context. No models are transferred back to MainActor. Now, after changing my project settings, I am getting a huge amount of warnings. Do I need to set all my model classes to non-isolated and the @ModelActor actor as well? Is there any new sample code to cover this topic ... did not find anything for now. Thanks in advance, Marc

We are trying to solve for the following condition with SwiftData + CloudKit: Lots of data in CloudKit Perform "app-reset" to clear data & App settings and start fresh. Reset data models with try modelContext.delete(model:_) myModel.count() confirms local deletion (0 records); but iCloud Console shows expectedly slow process to delete. Old CloudKit data is returning during the On Boarding process. Questions: • Would making a new iCloud Zone for each reset work around this, as the new zone would be empty? We're having trouble finding details about how to do this with SwiftData. • Would CKSyncEngine have a benefit over the default SwiftData methods? Open to hearing if anyone has experienced a similar challenge and how you worked around it!

I have an app that uses CKShare to allow users to share CloudKit data with other users. With the first build of the iOS 26, I'm seeing a few issues: I'm not able to add myself as a participant anymore when I have the link to a document. Some participants names no longer show up in the app. Looking at the release notes for iOS & iPadOS 26 Beta, there is a CloudKit section with two bullets: CloudKit sharing URLs do not launch third-party apps. (151778655) The request access APIs, such as CKShareRequestAccessOperation, are available in the SDK but are currently nonfunctional. (151878020) It sounds like the first issue is addressed by the first bullet, although the error message makes me wonder if I need to make changes to my iCloud account permissions or something in order to open it. It works fine in iOS 18.5. This is the error I get when I try to open a link to a shared document (I blocked out my email address, which is what was in quotes): As far as the second issue, I am really confused about what is going on. Some names still show up, while others do not. I can't find a pattern, and the missing users are not on the iOS 26 beta. The release notes mention CKShareRequestAccessOperation being nonfunctional, which is new in the beta and has some minor documentation, but I can't find information about how it's supposed to be used yet. In previous years there have been WWDC sessions about what's new in CloudKit, but I haven't found anything that talks about these changes to document sharing. Is there a guide or session somewhere that I'm missing? Does anyone know what's going on with these changes to CloudKit?

Updated the phone to iOS 26.1 and now the app is not working anymore, even previously approved version published on App Store which works perfectly on iOS 26.0.1, and iOS 18+. I deleted the app from the phone and installed fresh from App Store, still the same. Logic is that on start app copies previously prepared SwiftData store file (using the same models) from app bundle to Documents directory and uses it. Currently app just hungs with loader spinner spinning as it can t connect to the store. Getting this error in console when running from Xcode on real device with iOS 26.1 installed: CoreData: error: CoreData: error: Store failed to load. <NSPersistentStoreDescription: 0x10c599e90> (type: SQLite, url: file:///var/mobile/Containers/Data/Application/DA32188D-8887-48F7-B828-1F676C8FBEF8/Documents/default.store) with error = Error Domain=NSCocoaErrorDomain Code=134140 "Persistent store migration failed, missing mapping model." UserInfo={sourceModel=(<NSManagedObjectModel: 0x10c503ac0>) isEditable 0, entities { /// there goes some long models description addPersistentStoreWithType:configuration:URL:options:error: returned error NSCocoaErrorDomain (134140) Any help or workaround will be greatly appreciated.

How do I filter data using @Query with a Set of DateComponents? I successfully saved multiple dates using a MultiDatePicker in AddView.swift. In ListView.swift, I want to retrieve all records for the current or today’s date. There are hundreds of examples using @Query with strings and dates, but I haven’t found an example of @Query using a Set of DateComponents Nothing will compile and after hundreds and hundreds of attempts, my hair is turning gray. Please, please, please help me. For example, if the current date is Tuesday, March 4 205, then I want to retrieve both records. Since both records contain Tuesday, March 4, then retrieve both records. Sorting works fine because the order by clause uses period which is a Double. Unfortunately, my syntax is incorrect and I don’t know the correct predicate syntax for @Query and a Set of DateComponents. Class Planner.swift file import SwiftUI import SwiftData 
 @Model class Planner { //var id: UUID = UUID() var grade: Double = 4.0 var kumi: Double = 4.0 var period: Double = 1.0 var dates: Set<DateComponents> = [] init( grade: Double = 4.0, kumi: Double = 4.0, period: Double = 1.0, dates: Set<DateComponents> = [] ) { self.grade = grade self.kumi = kumi self.period = period self.dates = dates 
 } } @Query Model snippet of code does not work The compile error is to use a Set of DateComponents, not just DateComponents. @Query(filter: #Predicate<Planner> { $0.dates = DateComponents(calendar: Calendar.current, year: 2025, month: 3, day: 4)}, sort: [SortDescriptor(\Planner.period)]) var planner: [Planner] ListView.swift image EditView.swift for record #1 DB Browser for SQLlite: record #1 (March 6, 2025 and March 4, 2025) 
 
 [{"isLeapMonth":false,"year":2025,"day":6,"month":3,"calendar":{"identifier":"gregorian","minimumDaysInFirstWeek":1,"current":1,"locale":{"identifier":"en_JP","current":1},"firstWeekday":1,"timeZone":{"identifier":"Asia\/Tokyo"}},"era":1},{"month":3,"year":2025,"day":4,"isLeapMonth":false,"era":1,"calendar":{"locale":{"identifier":"en_JP","current":1},"timeZone":{"identifier":"Asia\/Tokyo"},"current":1,"identifier":"gregorian","firstWeekday":1,"minimumDaysInFirstWeek":1}}]
 EditView.swift for record #2 DB Browser for SQLlite: record #2 (March 3, 2025 and March 4, 2025) 
 [{"calendar":{"minimumDaysInFirstWeek":1,"locale":{"current":1,"identifier":"en_JP"},"timeZone":{"identifier":"Asia\/Tokyo"},"firstWeekday":1,"current":1,"identifier":"gregorian"},"month":3,"day":3,"isLeapMonth":false,"year":2025,"era":1},{"year":2025,"month":3,"era":1,"day":4,"isLeapMonth":false,"calendar":{"identifier":"gregorian","current":1,"firstWeekday":1,"minimumDaysInFirstWeek":1,"timeZone":{"identifier":"Asia\/Tokyo"},"locale":{"current":1,"identifier":"en_JP"}}}]
 
 Any help is greatly appreciated.

I'm trying to set up server-to-server authentication with CloudKit Web Services, but keep getting AUTHENTICATION_FAILED errors. I've tried multiple environment settings and debugging approaches without success. What I've Tried I created a Swift script to test the connection. Here's the key part that handles the authentication: // Get current ISO 8601 date let iso8601Formatter = ISO8601DateFormatter() iso8601Formatter.formatOptions = [.withInternetDateTime] let dateString = iso8601Formatter.string(from: Date()) // Create SHA-256 hash of request body let bodyHash = SHA256.hash(data: bodyData).compactMap { String(format: "%02x", $0) }.joined() // Get path from URL let path = request.url?.path ?? "/" // String to sign let method = request.httpMethod ?? "POST" let stringToSign = "\(method):\(path):\(dateString):\(bodyHash)" // Sign the string with EC private key let signature = try createSignature(stringToSign: stringToSign) // Add headers request.setValue(dateString, forHTTPHeaderField: "X-Apple-CloudKit-Request-ISO8601Date") request.setValue(KEY_ID, forHTTPHeaderField: "X-Apple-CloudKit-Request-KeyID") request.setValue(signature, forHTTPHeaderField: "X-Apple-CloudKit-Request-SignatureV1") } I've made a request to this endpoint: What's Happening I get a 401 status with this response: "uuid" : "173179e2-c5a5-4393-ab4f-3cec194edd1c", "serverErrorCode" : "AUTHENTICATION_FAILED", "reason" : "Authentication failed" } What I've Verified The key validates correctly and generates signatures The date/time is synchronized with the server The key ID matches what's in CloudKit Dashboard I've tried all three environments: development, Development (capital D), and production The container ID is formatted correctly Debug Information My debugging reveals: The EC key is properly formatted (SEC1 format) Signature generation works No time synchronization issues between client and server All environment tests return the same 401 error Questions Has anyone encountered similar issues with CloudKit server-to-server authentication? Are there specific container permissions needed for server-to-server keys? Could there be an issue with how the private key is formatted or processed? Are there any known issues with the CloudKit Web Services API that might cause this? Any help would be greatly appreciated!

I’m seeing persistent issues with iCloud Drive hydration and Finder sync on a new M4 MacBook Pro running Sequoia 15.5 (24F74). The same folders hydrate correctly on other Macs (Intel and M1), but not on the M4. ✅ Tried: – killall bird – Safe Mode boot – Toggling iCloud Drive and System Settings > Apple ID – Isolating network, user profile, and running First Aid 🔍 Findings: – EtreCheck report shows consistent high CPU usage from bird with no resolution. – Console logs suggest bird is waiting on local metadata index. – No VPNs installed. No third-party sync tools active. I’ve sanitized and attached the EtreCheck report as text for reference (or can paste if needed). ❓ Questions: 1. Is this a known issue on M4 systems or Sequoia 15.5? 2. Could file system ownership have been impacted by command-line tools? 3. Is there a safe method to reset bird metadata or iCloud sync state locally? Any guidance from Apple or other developers would be appreciated. Thanks!

I get this error, i have my own DIKit, and i want to use swiftdata for showing info from persisten model. It works all over the app, but i get this error with my .sheet. // JobCreationView.swift // Features // // Created by Jens Vik on 26/03/2025. // import SwiftUI import DesignKit import DIKit import PresentationKit import CoreKit import DomainKit import SwiftData public struct JobCreationView: View { @Binding var isPresented: Bool // Inject view model using DIKit's property wrapper @Injected((any JobCreationViewModelProtocol).self) private var viewModel // Form state @Injected(ModelContext.self) private var modelContext @State private var date = Date() @State private var isASAP = false @State private var price = "" @State private var jobType = "Fiks" @State private var description = "" // Available job types private let jobTypes = ["Fiks", "Fiksit"] @Query private var userContexts: [UserContextModel] public init(isPresented: Binding<Bool>) { self._isPresented = isPresented print("DEBUG: JobCreationView initialized") } public var body: some View { let city = userContexts.first?.city ?? "Loading..." NavigationView { Form { Section(header: Text("Location")) { Text(city) } Section(header: Text("Details")) { TextField("Price", text: $price) .keyboardType(.numberPad) Picker("Job Type", selection: $jobType) { ForEach(jobTypes, id: \.self) { type in Text(type).tag(type) } } .pickerStyle(SegmentedPickerStyle()) TextEditor(text: $description) .frame(minHeight: 100) .overlay( RoundedRectangle(cornerRadius: 8) .stroke(Color.gray.opacity(0.2), lineWidth: 1) ) } } .navigationBarTitle("Create Job", displayMode: .inline) .navigationBarItems( leading: Button("Cancel") { isPresented = false }, trailing: Button("Post") { // Post functionality will be added later isPresented = false } .disabled( (!isASAP && date < Date()) || price.isEmpty || description.isEmpty) ) } } } How bad is this macro error? error: the replacement path doesn't exist: "/var/folders/dn/x3x4wwkd335_rl91by3tqx5w0000gn/T/swift-generated-sources/@_swiftmacro_10FeatureKit15JobCreationViewV12userContexts33_CDDE5BE156468A2E8CC9B6A7E34B1006LL5QueryfMa.swift" error: the replacement path doesn't exist: "/var/folders/dn/x3x4wwkd335_rl91by3tqx5w0000gn/T/swift-generated-sources/@_swiftmacro_10FeatureKit15JobCreationViewV12userContexts33_CDDE5BE156468A2E8CC9B6A7E34B1006LL5QueryfMa.swift" error: the replacement path doesn't exist: "/var/folders/dn/x3x4wwkd335_rl91by3tqx5w0000gn/T/swift-generated-sources/@_swiftmacro_10FeatureKit15JobCreationViewV12userContexts33_CDDE5BE156468A2E8CC9B6A7E34B1006LL5QueryfMa.swift" error: the replacement path doesn't exist: "/var/folders/dn/x3x4wwkd335_rl91by3tqx5w0000gn/T/swift-generated-sources/@_swiftmacro_10FeatureKit15JobCreationViewV12userContexts33_CDDE5BE156468A2E8CC9B6A7E34B1006LL5QueryfMa.swift" error: the replacement path doesn't exist: "/var/folders/dn/x3x4wwkd335_rl91by3tqx5w0000gn/T/swift-generated-sources/@_swiftmacro_10FeatureKit15JobCreationViewV12userContexts33_CDDE5BE156468A2E8CC9B6A7E34B1006LL5QueryfMa.swift"

I have been trying to find out the app limits to my app when released into the app store, I understand that in the public database the app worldwide can use 200g of bandwidth free per month. What happens after that? is it throttled? is there a pricing structure for overages? thanks

Hi, I keep trying to use transformable to store an array of strings with SwiftData, and I can see that it is activating the transformer, but it keeps saying that I am still using NSArray instead of NSData. *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Unacceptable type of value for attribute: property = "category"; desired type = NSData; given type = Swift.__SwiftDeferredNSArray; value = ( yo, gurt ).' terminating due to uncaught exception of type NSException CoreSimulator 1010.10 - Device: iPhone 16 18.0 (6879535B-3174-4025-AD37-ED06E60291AD) - Runtime: iOS 18.0 (22A3351) - DeviceType: iPhone 16 Message from debugger: killed @Model class MyModel: Identifiable, Equatable { @Attribute(.transformable(by: StringArrayTransformer.self)) var category: [String]? @Attribute(.transformable(by: StringArrayTransformer.self)) var amenities: [String]? var image: String? var parentChunck: HenricoPostDataChunk_V1? init(category: [String]?, amenities: [String]?) { self.category = category self.amenities = amenities } } class StringArrayTransformer: ValueTransformer { override func transformedValue(_ value: Any?) -> Any? { print(value) guard let array = value as? [String] else { return nil } let data = try? JSONSerialization.data(withJSONObject: array, options: []) print(data) return data } override func reverseTransformedValue(_ value: Any?) -> Any? { guard let data = value as? Data else { return nil } let string = (try? JSONSerialization.jsonObject(with: data, options: [])) as? [String] print(string) return string } override class func transformedValueClass() -> AnyClass { return NSData.self } override class func allowsReverseTransformation() -> Bool { return true } static func register() { print("regitsering") ValueTransformer.setValueTransformer(StringArrayTransformer(), forName: .stringArrayTransformerName) } } extension NSValueTransformerName { static let stringArrayTransformerName = NSValueTransformerName("StringArrayTransformer") }

Setup I am running a versionedSchema for my SwiftData model and attempting a migration. The new version contains a new attribute, with a type of a new custom enum defined in the @Model class, a default value, and a private(set). Migration was completed with a migrationPlan with nil values for willMigrate and didMigrate. Example - Previous Version @Model class MyNumber { var num: Int init() { // Init Code } } Example - Newest Version @Model class MyNumber { var num: Int private(set) var rounding: RoundAmount = MyNumber.RoundAmount.thirtyMinute init() { // Init Code } enum RoundAmount { case fiveMinute, tenMinute, thirtyMinute } } Issue Running this code, I get a swiftData error for “SwiftData/ModelCoders.swift:1585: nil value passed for a non-optional keyPath, /MyNumber.rounding” I assume this means a failure of the swiftData lightweight migration? I have reverted the version, removed private(set) and re-tried the migration with no success. Using the versionedSchema with migrationPlans, are lightweight migrations possible? Could this be an issue with the use of a custom enum? Other changes in my actual project migrated successfully so I’m lost on why I’m having this issue.

Hi, I keep trying to use transformable to store an array of strings with SwiftData, and I can see that it is activating the transformer, but it keeps saying that I am still using NSArray instead of NSData. *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Unacceptable type of value for attribute: property = "category"; desired type = NSData; given type = Swift.__SwiftDeferredNSArray; value = ( yo, gurt ).' terminating due to uncaught exception of type NSException CoreSimulator 1010.10 - Device: iPhone 16 18.0 (6879535B-3174-4025-AD37-ED06E60291AD) - Runtime: iOS 18.0 (22A3351) - DeviceType: iPhone 16 Message from debugger: killed @Model class MyModel: Identifiable, Equatable { @Attribute(.transformable(by: StringArrayTransformer.self)) var category: [String]? @Attribute(.transformable(by: StringArrayTransformer.self)) var amenities: [String]? var image: String? var parentChunck: MyModelDataChunk_V1? init(category: [String]?, amenities: [String]?) { self.category = category self.amenities = amenities } } class StringArrayTransformer: ValueTransformer { override func transformedValue(_ value: Any?) -> Any? { print(value) guard let array = value as? [String] else { return nil } let data = try? JSONSerialization.data(withJSONObject: array, options: []) print(data) return data } override func reverseTransformedValue(_ value: Any?) -> Any? { guard let data = value as? Data else { return nil } let string = (try? JSONSerialization.jsonObject(with: data, options: [])) as? [String] print(string) return string } override class func transformedValueClass() -> AnyClass { return NSData.self } override class func allowsReverseTransformation() -> Bool { return true } static func register() { print("regitsering") ValueTransformer.setValueTransformer(StringArrayTransformer(), forName: .stringArrayTransformerName) } } extension NSValueTransformerName { static let stringArrayTransformerName = NSValueTransformerName("StringArrayTransformer") }

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?

Hi, I'm considering using the new SwiftData class inheritance for a new app I'm building. I have a few questions: Is it working well enough for production? I have a number of different object types in my app. Some of them are very similar, and there's always a balance to be struck when it comes to splitting them into different types using class inheritance. Are there some good advice on when to use multiple classes instead of squeezing my object types into a single class? Is there advice against using class inheritance in multiple levels (3-4)? Claes

I'm setting up App Entities for my SwiftData models and I'm not sure about the best way to reference SwiftData model properties in the AppEntity. I have a SwiftData model with many properties: @Model final class Contact { @Attribute(.unique) var id: UUID = UUID() var name: String var phoneNumber: String var email: String var website: URL? var birthday: Date? var notes: String // ... many more properties } I want to expose these properties on my AppEntity so they're available for system features, such as giving Apple Intelligence more context about on-screen content. struct ContactEntity: AppEntity { var id: UUID @Property(title: "Name") var name: String @Property(title: "Phone") var phoneNumber: String @Property(title: "Email") var email: String // ... all the other properties } I couldn't find guidance in the documentation for this specific situation. I've considered two approaches: Add @Property variables to the AppEntity for each SwiftData model property and copy all values from the SwiftData model to the AppEntity in the AppEntity initializer — but I recall this being discouraged in previous WWDC sessions since it duplicates data and can become stale Use @ComputedProperty to fetch the model and access the single properties — this seems like an alternative, but fetching the entire model just to access individual properties doesn't feel right What is the recommended approach when SwiftData is the data source? Thank you!

Hi, I am testing a situation with shared CKRecords where the data in the CKRecord syncs fine, but the creatorUserRecordID.recordName and lastModifiedUserRecordID.recordName shows "defaultOwner" (which maps to the CKCurrentUserDefaultName constant) even though I made sure I edit the CKRecord value from a different iCloud account. In fact, on the CloudKit dashboard, it shows the correct user recordIDs in the metadata for the 'Created' and 'Modified' fields, but not in the CKRecord. I am mostly testing this on the iPhone simulator with the debugger attached. Is that a possible reason for this, or is there some other reason the lastModifiedUserRecordID is showing the value for 'CKCurrentUserDefaultName'? It would be pretty difficult to build in functionality to look up changes by a different userID if this is the case.