Hi, I'm about to adopt .externalStorage but I will also use CloudKit in the near future. I did not find any reference that list of requirements for SwiftData models to be used with CloudKit, only for Core Data models. It seems those Core Data requirements (like no-unique) apply to SwiftData as well. However I did not find any info on this: Can @Attribute(.externalStorage) be used when I want to sync my model with CloudKit?

Hello, Prior to iOS 17, it was possible to request user discoverability by calling ‚requestApplicationPermission‘. But now it is deprecated. How is the intended way to do this now? How this is for example handled in the Music App? I think this should be a similar approach. Currently the only option for me seems to save the Email-Address (and maybe phone number) in the CloudKit public database, that other user can discover by this. But that the problem exists, that we need to fetch for changes at phone numbers and mail addresses that are linked to the iCloud account (because user might change anything). Is there a more elegant solution, than just checking the current email addresses and phone numbers at each start of the application (if that is even possible)? For example the Music App has that Switch "Find my by Apple-ID" but I don't know how this is handled in the background. Thanks!

When I go to Settings and tap on the account, choose iCloud>manage account storage and try to delete the storage associated with an app id developer mode, it doesn't give me the option to delete the data. I have tried using the CloudKit Console to delete the container data, but the entry for the app is still there. How do I delete it?

SwiftData includes support for CloudKit sync. However, I don't see any way to add conflict resolution behavior. For example, if different devices set different values for a field, or if a relationship is orphaned because of a deletion on another device, the application has to handle this somehow. In Core Data (which SwiftData wraps), you can handle this with the conflict resolution system (docs) and classes like NSMergePolicy. Is any of this accessible in SwiftData? If not, how do you deal with conflicts when syncing a SwiftData model with the cloud?

Recently, I have made quite extensive changes to my schema and need to migrate my CoreData + CloudKit model to a new version. The changes require me to use a custom NSEntityMigrationPolicy because I have a rather complex mapping between some old entities and new entities. I have added a new model version. Deleted some entities, and added some entities. I have defined the NSEntityMigrationPolicy with createDestinationInstances(forSource:in:manager:) and createRelationships(forDestination:in:manager:). I have created a new Core Data Mapping Model. This was probably unnecessary. Within the Core Data Mapping Model, I have specified Custom Policy for all entities. In my container setup, I added two options, as below: storeDescription.setOption(false as NSNumber, forKey: NSMigratePersistentStoresAutomaticallyOption) storeDescription.setOption(false as NSNumber, forKey: NSInferMappingModelAutomaticallyOption) I mostly followed a "Core Data Heavyweight Migration" guide. I'm unable to share the link, but it can be quite easily found on the web. (It's not for CloudKit specifically.) When I run my app, I am getting the most basic of errors, which is: The managed object model version used to open the persistent store is incompatible with the one that was used to create the persistent store. So I guess that migration wasn't even attempted, which makes sense because I set NSMigratePersistentStoresAutomaticallyOption to false. I tried to go beyond what I could find on the web and attempted to manually initialize migration: let sourceModel = container.persistentStoreCoordinator.managedObjectModel guard let modelURL = Bundle.main.url(forResource: "MyModelName", withExtension: "xcdatamodeld") else { fatalError("Unable to locate model file.") } guard let destinationModel = NSManagedObjectModel(contentsOf: modelURL) else { fatalError("Unable to load destination model.") } let migrationManager = NSMigrationManager(sourceModel: sourceModel, destinationModel: destinationModel) let mappingModel = NSMappingModel(from: [Bundle.main], forSourceModel: sourceModel, destinationModel: destinationModel)! migrationManager.currentEntityMapping.entityMigrationPolicyClassName = "MyMigrationPolicyClassName" I am then stuck at the migrateStore(from:type:mapping:to:type:) method. It seems to target only local storage, not CloudKit. Otherwise, what do I provide for URLs and types? Any guidance for custom logic CoreData with CloudKit migration would be greatly appreciated.

I have been working on an ios application which I decided to use the new SwiftData architecture, and I now have realized that SwiftData does not support public or shared databases using SwiftData. I am a new and upcoming Swift developer, who has been self learning the Apple Swift technology. I just learned in this forum that Swift Data does not support Public and Shared Data and I also understand that no plans that have been announced to addressed this feature in the IOS 18 release time frame. The use case for my application is to implement a social type application, something like applications including X, facebook, etc. These type of applications appear to use Public, Shared and Private data in various existing Apple application. I would like to complete an application using Swift using ICloud, but I must assume that these current social applications are using other technologies. I am assuming you can do this in Core Data, but my understanding is Apple is asking that we use Swift Data to replace core data. I also am assuming that Swift data is built on core data technology layers. So ... to me it seems hopeful, somehow, to accomplish this using IOS 17 and follow the recommend Swift Data Path. What are my options for completing these data objectives in IOS? I hope I am addressing these questions in the proper and best forum? Much thanks for any suggestions.

There is no iCloud option in the settings. When I use CloudKit I get Error synchronizing with cloud for store Error Domain=SyncedDefaults Code=8888 "No account"

I am following this document from Apple to implement sharing with CloudKit. In it, Apple says NSPersistentCloudKitContainer uses CloudKit zone sharing to share objects. Each share has its own record zone on the CloudKit server. CloudKit has a limit on how many record zones a database can have. What is the record zone limit for a private CloudKit database? I can find information about record and participant limits but not on record zone limits.

How can we identify whether the remote change notification is triggered because some data was changed on a different device and it is downloaded from CloudKit, or it is triggered from the current device because new entity was saved into database. Because this notification is posted when both remote data is downloaded or local data is created. It would be great if there is a way to understand the origin of the notification.

Has anyone successfully persisted Color, particularly in SwiftData? So far my attempts have failed: Making Color conform to Codable results in a run time error (from memory something about ColorBox). Color.Resolved already conforms Codable but this results in "SwiftData/ModelCoders.swift:124: Fatal error: Composite Coder only supports Keyed Container" None of the other color types conform to Codable (CGColor, NSColor and UIColor) so does the swift language really not have a persistable color type?

CoreData: Zone metadata is missing it's encoded share data but is marked for a mutation: <CKRecordZoneID: 0x600003f044e0; zoneName=com.apple.coredata.cloudkit.share.30BE5FAE-3FE0-4142-90C4-E78FFA90B2A2, ownerName=defaultOwner> - <decode: bad range for [%@] got [offs:312 len:1242 within:0]>

I deployed Xcode to iPhone, emulator and iPhone, and iCloud data is synchronized. But I am using testlight for distribution, so I cannot synchronize. I did not respond in iCloud Kit Database developer mode, and now I have changed to production mode, but there is no response, so I cannot synchronize. That's why.

A few months back, I launched an app that operated solely on a local level. Recently, I've begun the process of integrating it with CloudKit, and so far, the model integration has been successful. I've utilized SwiftData for this task, making it relatively straightforward to adjust the models, as shown below: ` @Relationship(deleteRule: .cascade, inverse: \ItemForCategory.category) var itemForCategory : [ItemForCategory]? = [ItemForCategory]() ` In my initial version of the code, the widget functioned perfectly. However, I've encountered an error recently stating Missing return in instance method expected to return 'ItemForCategory?'. @MainActor private func getLastItem () -> ItemForCategory? { guard let modelContainer = try? ModelContainer(for: Category.self) else { return nil } let descriptor = FetchDescriptor<Category>() let appCategories = try? modelContainer.mainContext.fetch(descriptor) let lastItem = appCategories?.compactMap { $0.itemForCategory }.last return lastItem } The error surfaces at the return line of code. I'm hopeful that someone can assist me in resolving this issue. Thank you very much.

I'm using CoreData+CloudKit. It works fine in development, so I deployed to production. But I cannot see the data in CloudKit DataBase in a testflight version. I don't know where I missed. Can I just run in Release mode to check it works?

It still didn't work when I signed in again

Hello, does anybody know how Apple anonymizes and aggregates the analytics provided to us devs? I'm interested in understanding the extent of their privacy safeguards. Do they employ federated analytics, or do they use a less effective method?

Hello. I recently released a new version (2.6) of my CloudKit syncing CoreData based app. The new version uses v18 of my data model. V18 is exactly like v17, except for a new optional string field in one of the entities. I diffed the two model versions to be extra sure. During my test I did not encounter any crash, and I also tested automatic migration, installing 2.55 and building 2.6 on top of it. No troubles. However my crash logger reports a number of crashes among my users. It's not a huge numbers (10 users over about 900 or more) but I am surprised it crashes at all. The crash happens when I call NSPersistentCloudKitContainer.loadPersistentStores, I get this error in the completion block: The model used to open the store is incompatible with the one used to create the store" I always assumed these slight changes (new field added to an existing model) did not require a manual migration. Any suggestions?

I use UserDefaults to store a variety of user data / preferences. Recently, I have started getting somewhat frequent complaints from users that their settings have been reset. There doesn't appear to be a rhyme or reason to the issue (some users have all of their data reset just once, while others are seeing that one of their settings resets very frequently). I haven't been able to pinpoint what the root cause is, but I figure that it must have something to do with UserDefaults (either all of it or only certain keys) somehow getting erased. As I figure out the root cause, I figure that a good solution in the meantime is to backup UserDefaults in some way (e.g. perhaps to iCloud?). Is there a standard / best-practice way of doing this?

Hello, we are planning to migrate an app that uses iCloud documents to store some documents that the user can upload/download and modify. In the official overview of App Transfer here, there are information related to CloudKit Containers and KVS but nothing related to iCloud Documents. The content of iCloud Documents is accessed using FileManager.default.url(forUbiquityContainerIdentifier: containerID) where the containerID has the form iCloud.com.things.things, even if in the official documentation it is written that the identifier must be prefixed with the Team ID. With this ID the storage works properly and we never experienced problems. Do you know if migrating an app with this functionality can be problematic? Do you know if the Team ID is somehow used even if not explicitly passed in the call to the function? Thank you and have a nice day!

I have an app that relies on CloudKit notifications for a core feature, but for about a week now the app is not receiving any CloudKit notifications. This follows a week in which I received "status 500" errors from CloudKit and my app was rendered useless. Those errors mysteriously stopped happening, but my app is still hindered by the lack of CloudKit notifications. I have not gotten any response from Apple on this, despite several attempts through various channels. It's not tenable to build apps that users rely on based on a platform that is so unreliable, and for which support is essentially nonexistent. To any CloudKit developers reading this: Please follow up with me so that I can resolve these issues for my users.