I am using SwiftData with CloudKit to synchronize data across multiple devices, and I have encountered an issue: occasionally, abnormal sync behavior occurs between two devices (it does not happen 100% of the time—only some users have reported this problem). It seems as if synchronization between the two devices completely stops; no matter what operations are performed on one end, the other end shows no response. After investigating, I suspect the issue might be caused by both devices simultaneously modifying the same field, which could lead to CloudKit's logic being unable to handle such conflicts and causing the sync to stall. Are there any methods to avoid or resolve this situation? Of course, I’m not entirely sure if this is the root cause. Has anyone encountered a similar issue?

In a document based SwiftData app for macOS, how do you go about opening a (modal) child window connected to the ModelContainer of the currently open document? Using .sheet() does not really result in a good UX, as the appearing view lacks the standard window toolbar. Using a separate WindowGroup with an argument would achieve the desired UX. However, as WindowGroup arguments need to be Hashable and Codable, there is no way to pass a ModelContainer or a ModelContext there: WindowGroup(id: "myWindowGroup", for: MyWindowGroupArguments.self) { $args in ViewThatOpensInAWindow(args: args) } Is there any other way?

The stuff I've found by searching has confused me, so hopefully someone can help simplify it for me? I have an app (I use it for logging which books I've given away), and I could either add a bunch of things to the app, or I could have another app (possibly a CLI tool) to generate some reports I'd like.

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?

The NSMetadataUbiquitousItemDownloadingStatusKey indicates the status of a ubiquitous (iCloud Drive) file. A key value of NSMetadataUbiquitousItemDownloadingStatusDownloaded is defined as indicating there is a local version of this file available. The most current version will get downloaded as soon as possible . However this no longer occurs since iOS 18.4. A ubiquitous file may remain in the NSMetadataUbiquitousItemDownloadingStatusDownloaded state for an indefinite period. There is a workaround: call [NSFileManager startDownloadingUbiquitousItemAtURL: error:] however this shouldn't be necessary, and introduces delays over the previous behaviour. Has anyone else seen this behaviour? Is this a permanent change? FB17662379

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.

We are currently implementing a custom iCloud sync for our macOS and iOS apps using CloudKit. Syncing works fine as long as the number of record sends is relatively small. But when we test with a large number of changes ( 80,000+ CKRecords ) we start running into problems. Our sending strategy is very conservative to avoid rate limits: We send records sequentially in batches of 250 records With about 2 seconds pause between operations Records are small and contain no assets (assets are uploaded separately) At some point we start receiving: “Database commit size exceeds limit” After that, CloudKit begins returning rate-limit errors with retryAfter-Information in the error. We wait for the retry time and try again, but from this moment on, nothing progresses anymore. Every subsequent attempt fails. We could not find anything in the official documentation regarding such a “commit size” limit or what triggers this failure state. So my questions are: Are there undocumented limits on the total number of records that can exist in an iCloud database (private or shared)? Is there a maximum volume of record modifications a container can accept within a certain timeframe, even if operations are split into small batches with pauses? Is it possible that sending large numbers of records in a row can temporarily or permanently “stall” a CloudKit container? Any insights or experiences would be greatly appreciated. Thank you!

Hello everyone, I am experiencing a persistent authentication error when querying a custom user profile record, and the error message seems to be a red herring. My Setup: I have a custom CKRecord type called ColaboradorProfile. When a new user signs up, I create this record and store their hashed password, salt, nickname, and a custom field called loginIdentifier (which is just their lowercase username). In the CloudKit Dashboard, I have manually added an index for loginIdentifier and set it to Queryable and Searchable. I have deployed this schema to Production. The Problem: During login, I run an async function to find the user's profile using this indexed loginIdentifier. Here is the relevant authentication code: func autenticar() async { // ... setup code (isLoading, etc.) let lowercasedUsername = username.lowercased() // My predicate ONLY filters on 'loginIdentifier' let predicate = NSPredicate(format: "loginIdentifier == %@", lowercasedUsername) let query = CKQuery(recordType: "ColaboradorProfile", predicate: predicate) // I only need these specific keys let desiredKeys = ["password", "passwordSalt", "nickname", "isAdmin", "isSubAdmin", "username"] let database = CKContainer.default().publicCloudDatabase do { // This is the line that throws the error let result = try await database.records(matching: query, desiredKeys: desiredKeys, resultsLimit: 1) // ... (rest of the password verification logic) } catch { // The error always lands here logDebug("Error authenticating with CloudKit: \(error.localizedDescription)") await MainActor.run { self.errorMessage = "Connection Error: \(error.localizedDescription)" self.isLoading = false self.showAlert = true } } } The Error: Even though my query predicate only references loginIdentifier, the catch block consistently reports this error: Error authenticating with CloudKit: Field 'createdBy' is not marked queryable. I know createdBy (the system creatorUserRecordID) is not queryable by default, but my query isn't touching that field. I already tried indexing createdBy just in case, but the error persists. It seems CloudKit cannot find or use my index for loginIdentifier and is incorrectly reporting a fallback error related to a system field. Has anyone seen this behavior? Why would CloudKit report an error about createdBy when the query is explicitly on an indexed, custom field? I'm new to Swift and I'm struggling quite a bit. Thank you,

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

Testing Environment: iOS 18.4.1 / macOS 15.4.1 I am working on an iOS project that aims to utilize the user's iCloud Drive documents directory to save a specific directory-based file structure. Essentially, the app would create a root directory where the user chooses in iCloud Drive, then it would populate user generated files in various levels of nested directories. I have been attempting to use NSMetadataQuery with various predicates and search scopes but haven't been able to get it to directly monitor changes to files or directories that are not in the root directory. Instead, it only monitors files or directories in the root directory, and any changes in a subdirectory are considered an update to the direct children of the root directory. Example iCloud Drive Documents (Not app's ubiquity container) User Created Root Directory (Being monitored) File A Directory A File B An insertion or deletion within Directory A would only return a notification with userInfo containing data for NSMetadataQueryUpdateChangedItemsKey relating to Directory A, and not the file or directory itself that was inserted or deleted. (Query results array also only contain the direct children.) I have tried all combinations of these search scopes and predicates with no luck: query.searchScopes = [ rootDirectoryURL, NSMetadataQueryUbiquitousDocumentsScope, NSMetadataQueryAccessibleUbiquitousExternalDocumentsScope, ] NSPredicate(value: true) NSPredicate(format: "%K LIKE '*.md'", NSMetadataItemFSNameKey) NSPredicate(format: "%K BEGINSWITH %@", NSMetadataItemPathKey, url.path(percentEncoded: false)) I do see these warnings in the console upon starting my query: [CRIT] UNREACHABLE: failed to get container URL for com.apple.CloudDocs [ERROR] couldn't fetch remote operation IDs: NSError: Cocoa 257 "The file couldn’t be opened because you don’t have permission to view it." "Error returned from daemon: Error Domain=com.apple.accounts Code=7 "(null)"" But I am not sure what to make of that, since it does act normally for finding updates in the root directory. Hopefully this isn't a limitation of the API, as the only alternative I could think of would be to have multiple queries running for each nested directory that I needed updates for.

My app uses iCloud to let users sync their files via their private iCloud Drive, which does not use CloudKit. FileManager.default.url(forUbiquityContainerIdentifier: nil)?.appending(component: "Documents") I plan to transfer my app to another developer account, but I'm afraid it will affect the access of the app to the existing files in that folder. Apple documentation doesn't mention this case. Has anyone done this before and can confirm if the app will continue to work normally after transferring? Thanks

I'm trying to use the new (in tvOS 26) video streaming service automatic login API from the VideoSubscriberAccount framework: https://developer.apple.com/documentation/videosubscriberaccount/vsuseraccountmanager/autosignintoken-swift.property It seems that this API requires an entitlement. This document suggests that the com.apple.smoot.subscriptionservice entitlement is required. https://developer.apple.com/documentation/videosubscriberaccount/signing-people-in-to-media-apps-automatically However, it seems more likely that com.apple.developer.video-subscriber-single-sign-on is the correct entitlement. https://developer.apple.com/documentation/bundleresources/entitlements/com.apple.developer.video-subscriber-single-sign-on Which is the correct entitlement and how do I obtain it? I don't want to fully comply with the video partner program. https://developer.apple.com/programs/video-partner/ I just want to use this one new automatic login feature.

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?

I have a CoreData model with two configuration - but several problems. Notably the viewContext only shows data from the .private configuration. Here is the setup: The private configuration holds entities, for example, User and Course and the shared one holds entities, for example, Player and League. I setup the NSPersistentStoreDescriptions to use the same container but with a databaseScope of .private/.shared and with the configuration of "Private"/"Shared". loadPersistentStores() does not report an error. If I try container.initializeCloudKitSchema() only the .private configuration produces CKRecord types. If I create a companion app using one configuration (w/ all entities) the schema initialization creates all CKRecord types AND I can populate some data in the .private and a created CKShare. I see that data in the CloudKit dashboard. If I axe the companion app and run the real thing w/ two configurations, the viewContext only has the .private data. Why? If when querying history I use NSPersistentHistoryTransaction.fetchRequest I get a nil return when using two configurations (but non-nil when using one).

Document based SwiftData apps do not autosave changes to the ModelContext at all. This issue has been around since the first release of this SwiftData feature. In fact, the Apple WWDC sample project (https://developer.apple.com/documentation/swiftui/building-a-document-based-app-using-swiftdata) does not persist any data in its current state, unless one inserts modelContext.save() calls after every data change. I have reported this under the feedback ID FB16503154, as it seemed to me that there is no feedback report about the fundamental issue yet. Other posts related to this problem: https://forums.developer.apple.com/forums/thread/757172 https://forums.developer.apple.com/forums/thread/768906 https://developer.apple.com/forums/thread/764189

We are using AgeRangeService.requestAgeRange(ageGates:in:) with an age gate of 18 to verify adult users. The system prompt always displays the lower-bound wording (“17 or Younger”), even when the app’s requirement is to verify users who are 18 or older. We understand the UI is system-controlled; however, this wording causes confusion for users, QA, and product teams, as it appears to indicate a child-only flow even when requesting adult verification. Based on the demonstration video, it appears that they have another more coherent message. In Apple's example, it is different, and it is correct that we need to specify 18 years or older in the implementation. A little more context might be helpful, but we are creating a kind of wrapper with React Native that receives that value as a parameter, which is 18.

Starting 20th March 2025, I see an increase in bandwidth and latency for one of my CloudKit projects. I'm using NSPersistentCloudKitContainer to synchronise my data. I haven't changed any CloudKit scheme during that time but shipped an update. Since then, I reverted some changes from that update, which could have led to changes in the sync behaviour. Is anyone else seeing any issues? I would love to file a DTS and use one of my credits for that, but unfortunately, I can't because I cannot reproduce it with a demo project because I cannot travel back in time and check if it also has an increase in metrics during that time. Maybe an Apple engineer can green-light me filing a DTS request, please.

About 4 months ago, I shipped the first version of my app with 4 versioned schemas that, unintentionally, had the same versionIdentifier of 1.2.0 in 2 of them: V1: 1.0.0 V2: 1.1.0 V3: 1.2.0 V4: 1.2.0 They are ordered correctly in the MigrationPlan, and they are all lightweight. Migration works, SwiftData doesn't crash on init and I haven't encountered any issues related to this. The app syncs with iCloud. Questions, preferable for anybody with knowledge of SwiftData internals: What will break in SwiftData when there are 2 duplicate numbers? Not that I would expect it to be safe, but does it happen to be safe to ship an update that changes V4's version to 1.3.0, what was originally intended?

CloudKit CKRecordZone Deletion Issue Problem: CloudKit record zones deleted via CKDatabase.modifyRecordZones(deleting:) or CKModifyRecordZonesOperation are successfully removed but then reappear. I suspect they are automatically reinstated by CloudKit sync, despite successful deletion confirmation. Environment: SwiftData with CloudKit integration Custom CloudKit zones created for legacy zone-based sharing Observed Behavior: Create custom zone (e.g., "TestZone1") via CKDatabase.modifyRecordZones(saving:) Copy records to zone for sharing purposes Delete zone using any CloudKit deletion API - returns success, no errors Immediate verification: Zone is gone from database.allRecordZones() After SwiftData/CloudKit sync or app restart: Zone reappears Reproduction: Tested with three different deletion methods - all exhibit same behaviour: modifyRecordZones(deleting:) async API CKModifyRecordZonesOperation (fire-and-forget) CKModifyRecordZonesOperation with result callbacks Zone deletion succeeds, change tokens (used to track updates to shared records) cleaned up But zones are restored presumably by CloudKit background sync Expected: Deleted zones should remain deleted Actual: Zones are reinstated, creating orphaned zones

I have tried to set up iCloud sync. Despite fully isolating and resetting my development environment, the app fails with: NSCocoaErrorDomain Code=134060 (PersistentStoreIncompatibleVersionHashError) What I’ve done: Created a brand new CloudKit container Created a new bundle ID and app target Renamed the Core Data model file itself Set a new model version Used a new .sqlite store path Created a new .entitlements file with the correct container ID Verified that the CloudKit dashboard shows no records Deleted and reinstalled the app on a real device Also tested with “Automatically manage signing” and without Despite this, the error persists. I am very inexperienced and am not sure what my next step is to even attempt to fix this. Any guidance is apprecitated.