CloudKit

RSS for tag

Store structured app and user data in iCloud containers that can be shared by all users of your app using CloudKit.

Posts under CloudKit tag

200 Posts

Post

Replies

Boosts

Views

Activity

CarPlay Question
Why is there no option as a CarPlay developer to enable the creation of an App to track and enter your car's maintenance records? I know the pat reply would be Apple doesn't want you to do this while car is in motion. But I would normally do this while parked at the dealership or other service provider no?
1
0
269
Mar ’25
Request to manually associate my CloudKit container with my app ID
Hello, My app has had CloudKit enabled for a while, but it's not working. I get the error "Invalid bundle ID for container". Configure CloudKit in your project from TN3164 suggests changing to a new container. I tried changing to a new container, but this leads to data loss. The article recommends: "If your CloudKit container is already used in the production environment and switching to a new container leads to data loss, consider filing a feedback report with the following information to request manually associating your CloudKit container with your app ID." Where can I request this manual association? Is there anything else I can do? Thank you for your time and assistance. I’d appreciate a prompt resolution, as this issue is blocking our update. Looking forward to guidance.
2
0
493
Mar ’25
Async Data with iCloud
DESCRIPTION I have an App use iCloud to save data. The App had a CoreData ManagedObject 'Product', 'Product' Object had an attribute name 'count' and it is a Double Type. I need to synchronises 'count' property across multiple devices. for example: I have a devices A、B. A device set 'Product.count' = 100. B device set 'Product.count' = 50. I hope the 'Product.count' == 150 that results. how to synchronises the 'Product.count' == 150 for multiple devices. If I have more devices in future, How to get the latest 'Product.count' that it is correct result.
4
0
632
Mar ’25
Log Into Apple Account
When a user first downloads my application they are prompted to sign into their apple account via a pop up. I have not had this pop up previously, I believe the change occurred after iOS18. I have functions that do a few things: Retrieves userRecordID Retrieves a userprofile(via userrecordid) from cloudkit.
2
0
405
Mar ’25
NSPersistentCloudKitContainer Import failed (incomprehensible archive)
I am using NSPersistentCloudKitContainer and I decided to add a property to an entity. I accidentally ran try! container.initializeCloudKitSchema(options: []) while using the production container in Xcode (com.apple.developer.icloud-container-environment) which throw a couple of errors and created some FAKE_ records in my production container. So I changed to my development container and ran the try! container.initializeCloudKitSchema(options: []) and now it succeeded. After that I cleaned up the FAKE_ records scattered in production container but in Xcode when I'm running I now get these logs in the console (and I can't seem to get rid of them): error: CoreData+CloudKit: -[NSCloudKitMirroringDelegate _importFinishedWithResult:importer:](1398): <PFCloudKitImporter: 0x300cc72c0>: Import failed with error: Error Domain=NSCocoaErrorDomain Code=4864 "*** -[NSKeyedUnarchiver _initForReadingFromData:error:throwLegacyExceptions:]: incomprehensible archive (0x53, 0x6f, 0x6d, 0x65, 0x20, 0x73, 0x61, 0x6d)" UserInfo={NSDebugDescription=*** -[NSKeyedUnarchiver _initForReadingFromData:error:throwLegacyExceptions:]: incomprehensible archive (0x53, 0x6f, 0x6d, 0x65, 0x20, 0x73, 0x61, 0x6d)} error: CoreData+CloudKit: -[NSCloudKitMirroringDelegate recoverFromError:](2310): <NSCloudKitMirroringDelegate: 0x302695770> - Attempting recovery from error: Error Domain=NSCocoaErrorDomain Code=4864 "*** -[NSKeyedUnarchiver _initForReadingFromData:error:throwLegacyExceptions:]: incomprehensible archive (0x53, 0x6f, 0x6d, 0x65, 0x20, 0x73, 0x61, 0x6d)" UserInfo={NSDebugDescription=*** -[NSKeyedUnarchiver _initForReadingFromData:error:throwLegacyExceptions:]: incomprehensible archive (0x53, 0x6f, 0x6d, 0x65, 0x20, 0x73, 0x61, 0x6d)} error: CoreData+CloudKit: -[NSCloudKitMirroringDelegate _recoverFromError:withZoneIDs:forStore:inMonitor:](2620): <NSCloudKitMirroringDelegate: 0x302695770> - Failed to recover from error: NSCocoaErrorDomain:4864 Recovery encountered the following error: (null):0 error: CoreData+CloudKit: -[NSCloudKitMirroringDelegate resetAfterError:andKeepContainer:](610): <NSCloudKitMirroringDelegate: 0x302695770> - resetting internal state after error: Error Domain=NSCocoaErrorDomain Code=4864 "*** -[NSKeyedUnarchiver _initForReadingFromData:error:throwLegacyExceptions:]: incomprehensible archive (0x53, 0x6f, 0x6d, 0x65, 0x20, 0x73, 0x61, 0x6d)" UserInfo={NSDebugDescription=*** -[NSKeyedUnarchiver _initForReadingFromData:error:throwLegacyExceptions:]: incomprehensible archive (0x53, 0x6f, 0x6d, 0x65, 0x20, 0x73, 0x61, 0x6d)} error: CoreData+CloudKit: -[NSCloudKitMirroringDelegate _requestAbortedNotInitialized:](2198): <NSCloudKitMirroringDelegate: 0x302695770> - Never successfully initialized and cannot execute request '<NSCloudKitMirroringExportRequest: 0x303a52d00> 548CB420-E378-42E5-9607-D23E7A2A364D' due to error: Error Domain=NSCocoaErrorDomain Code=4864 "*** -[NSKeyedUnarchiver _initForReadingFromData:error:throwLegacyExceptions:]: incomprehensible archive (0x53, 0x6f, 0x6d, 0x65, 0x20, 0x73, 0x61, 0x6d)" UserInfo={NSDebugDescription=*** -[NSKeyedUnarchiver _initForReadingFromData:error:throwLegacyExceptions:]: incomprehensible archive (0x53, 0x6f, 0x6d, 0x65, 0x20, 0x73, 0x61, 0x6d)}
3
1
497
Mar ’25
CKSyncEngine: Can Long-Offline Devices Miss CloudKit Change Notifications?
Problem Description: When a device (Device 2) stays offline for an extended period after a record is deleted from another synced device (Device 1) via CloudKit, is it possible for Device 2 to miss the deletion notification when it reconnects, even when using CKSyncEngine? This scenario raises questions about whether CKSyncEngine can reliably sync changes if CloudKit archives or purges metadata related to deletions during the offline period. Steps to Reproduce: At time t0: · Device 1 and Device 2 sync successfully via CKSyncEngine (shared record RecordA). Device 2 goes offline. On Device 1: · Delete RecordA; sync completes via CKSyncEngine. Wait for a duration potentially exceeding CloudKit’s change retention window (if such a window exists). Bring Device 2 back online. Observe synchronization: · Expected Behavior: CKSyncEngine removes RecordA from Device 2. · Observed Behavior: RecordA remains on Device 2. Key Questions: Under these conditions, can Device 2 permanently miss the deletion event due to CloudKit’s internal metadata management? Is there a documented retention policy for CloudKit’s change history, and how does CKSyncEngine handle scenarios where this history is truncated? What is the recommended pattern to ensure no events are missed, regardless of offline duration? Clarifications Needed: · If CloudKit does discard deletion metadata after a period, is this considered a framework limitation, or should developers implement additional safeguards? · Does CKSyncEngine log warnings or errors when it detects incomplete sync histories? Environment: · CKSyncEngine with SQLite · CloudKit Private Database · iOS/macOS latest versions Thank you for clarifying how CKSyncEngine is designed to handle this edge case!
1
0
252
Feb ’25
Request for Guidance on Cross-Platform Heart Rate Data Sharing
Dear Apple Developer Support, I hope this message finds you well. I am reaching out for guidance on a project that involves sharing heart rate data between an iOS app and an Android app. I have developed a watchOS app that continuously fetches heart rate data from an Apple Watch and displays it in a companion iOS app. Additionally, I have built an Android fitness app using Ionic Angular. My goal is to create a bridge that allows the heart rate data from the iOS app to be displayed continuously in the Android app. I am considering using a backend server (e.g., Node.js) to facilitate this data transfer. Could you please provide any insights or recommendations on the best approach for achieving this cross-platform data sharing? I would appreciate any guidance on potential challenges or limitations I might encounter. Thank you for your time and assistance. Sincerely, Venu Madhav
1
0
467
Feb ’25
CloudKit CKModifyRecordsOperation resulting in undocumented error "Internal Error" (1/3001); "MMCSEngineCreate failed"
I'm running into an undocumented error coming back from CloudKit operations. Specifically, I'm attempting to save new records via CKModifyRecordsOperation. I'm receiving this error for each of the records in the perRecordSaveBlock callback: &lt;CKError 0x3018ac3c0: "Internal Error" (1/3001); "MMCSEngineCreate failed"&gt; Is anyone else facing this error? It has been happening for several days and I'm finally getting around to reproduction with the Console app and logs. I have 16 records on my device locally that each one gets this error back. FB16547732 - CloudKit: CKModifyRecordsOperation saving new records results in Error &lt;CKError 0x3018ac1e0: "Internal Error" (1/3001); "MMCSEngineCreate failed"&gt;
2
0
554
Feb ’25
Records or Fields are Missing or Corrupt in Users Private CloudKit Databases (Recent Changes to CloudKit?)
Hi all, I've contacted Apple about this privately but I wanted to post this publicly too just to see if anyone else is experiencing the same issue. We use CloudKit to store "documents" (we'll call them) for our users. We use it directly, not via CoreData etc but through the lower level APIs. This has been working great for the last 9 months or so. Since a few days ago we've started receiving reports from users that their data has disappeared without a trace from their app. Obviously this is very serious and severe for us. We keep a local copy of the users data but if CloudKit tells us this data has been deleted we remove that local copy to keep in sync. Nothing has changed client side in terms of our code, and the only way we can see that could cause this, is a fetch that we perform asking for a list of the users "documents" is returning no rows/results, or possibly returning rows with invalid or missing fields. We have about 30,000 active users per day (1.5m requests/day) using CloudKit and we have only a handful of reports of this. Again this only started happening this week after 9 months of good service. Has anyone else noticed anything "strange" lately, fetches returning empty? fields missing? Is anyone at Apple aware of any recent changes to CloudKit? or outages? We're really unsure how or who should handle this and who we can escalate to? Any help appreciated. We have a workaround/mitigation on the way through review at the moment but this is a really big problem for us if we can't rely on CloudKit to remember users data reliably.
1
0
595
Feb ’25
Unable to delete CKShare
Running the Apple sample code “Sharing Core Data objects between iCloud users” has presented the following challenge: After the creation of a CKRecord in a Persistent CloudKit Container private database, the owner then shares it to a participant. All works fine. Then the Owner wants to stop sharing. That's fine too, although the CKRecord remains within the same shared zone within the owner's private database; it doesn't move back to the private database. Then the owner wants to delete the CKRecord completely. Deletion of the record works, but evidence of the CKShare within the shared zone still remains inside the owner's private database. It is clearly visible on the CloudKit dashboard. Probably doesn’t take up much memory but v messy and not cool. How to delete this CKShare completely, leaving no trace? Any ideas would be most gratefully received!
1
0
550
Feb ’25
SwiftData with shared and private containers
I was hoping for an update of SwiftData which adopted the use of shared and public CloudKit containers, in the same way it does for the private CloudKit container. So firstly, a big request to any Apple devs reading, for this to be a thing! Secondly, what would be a sensible way of adding a shared container in CloudKit to an existing app that is already using SwiftData? Would it be possible to use the new DataStore method to manage CloudKit syncing with a public or shared container?
11
18
3.5k
Feb ’25
SwiftData property marked ephemeral getting persisted in CloudKit
Am I misunderstanding the expected behavior here, or is there a bug in the behavior of @Attribute(.ephemeral) tagged SwiftData model properties? The documentation for .ephemeral says "Track changes to this property but do not persist". I started using .ephemeral because @Transient was inhibiting SwiftUI from reacting to changes to the property through @Observable. I am updating the value of my @Attribute(.ephemeral) property about once a second and I am seeing corresponding console log output showing the property as part of the generated CKRecord object. I then confirmed in the CloudKit dev portal that the .ephemeral property was added to the Record schema and contains real values. The behavior seems as though the .ephemeral property is being completely ignored. This is observed in a new Xcode project using SwiftData with CloudKit, Xcode 16.2, macOS 15.3.1 and during Build & Run testing on physical devices.
1
0
683
Feb ’25
NSPersistentCloudKitContainer uploads only a subset of records to public database in production environment
I'm having some issues where only a subset of records appear in CloudKit dashboard after I have saved some records in my iOS app using NSPersistentCloudKitContainer. I have noticed that when I'm running my app using the development environment of my CloudKit container everything works smoothly and is uploaded as expected but when I'm using the production environment only a subset of records are actually uploaded. I'm pulling my hair on how to debug this. -com.apple.CoreData.CloudKitDebug and -com.apple.CoreData.SQLDebug pukes out too much info in the console for me to pinpoint any issue.
1
0
661
Feb ’25
Share an object managed by NSPersistentCloudKitContainer with other users
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.
2
0
932
Feb ’25
MAJOR Core Data Issues with iOS 18 and sdk - Data Missing for many users?!
I just released an App update the didn't touch ANYTHING to do with Core Data (nothing changed in our Coredata code for at least 8 months). The update uses SDK for iOS 18 and Xcode 16.2 and the app now requires iOS 18 and was a minor bug patch and UI improvements for recent iOS changes. Since the update we are getting a steady trickle of users on iOS 18, some who allow the App to store data in iCloud (Cloudkit) and others who do not, all reporting that after the update to our recent release ALL their data is gone?! I had not seen this on ANY device until today when I asked a friend who uses the App if they had the issue and it turned out they did, so I hooked their device up to Xcode and ALL the data in the CoreData database was gone?! They are NOT using iCloud. There were no errors or exceptions on Xcode console but a below code returned NO records at all?! Chart is custom entity and is defined as: @interface Chart : NSManagedObject {} let moc = pc.viewContext let chartsFetch = NSFetchRequest<NSFetchRequestResult>(entityName:"Charts") // Fetch all Charts do { let fetchedCharts = try moc.fetch(chartsFetch) as! [Chart] for chart in fetchedCharts { .... } } A break point inside the do on fetchedCharts show there are NO objects returned. This is a serious issue and seems like an iOS 18 thing. I saw some people talking in here about NSFetchRequest issues with iOS 18. I need some guidance here from someone Apple engineer here who knows what the status of these NSFetchrequest bugs are and what possible workarounds are. Becasue this problem will grow for me as more users update to iOS 18.
13
0
2.3k
Feb ’25
Can't deploy CloudKit schema because of empty record? Why?
When I try to promote schema to production, I get following error: Cannot promote schema with empty type 'workspace', please delete the record type before attempting to migrate the schema again However, in hierarchical root record sharing, I think it should be completely legit use case where there is empty root record (in my case workspace) to which other records reference through ->parent reference. Am I missing something? Is this weird constraint imposed on CloudKit?
1
0
587
Feb ’25
Is there a guaranteed order for records in CKSyncEngine's handleFetchedRecordZoneChanges?
I have two recordTypes in CloudKit: Author and Book. The Book records have their parent property set to an Author, enabling hierarchical record sharing (i.e., if an Author record is shared, the participant can see all books associated with that author in their shared database). When syncing with CKSyncEngine, I was expecting handleFetchedRecordZoneChanges to deliver all Author records before their associated Book records. However, unless I’m missing something, the order appears to be random. This randomness forces me to handle two codepaths in my app (opposed to just one) to replicate CloudKit references in my local persistency storage: Book arrives before its Author → I store the Book but defer setting its parent reference until the corresponding Author arrives. Author arrives before its Books → I can immediately set the parent reference when each Book arrives. Is there a way to ensure that Author records always arrive before Book records when syncing with CKSyncEngine? Or is this behavior inherently unordered and I have to implement two codepaths?
1
0
612
Feb ’25
CKSyncEngine: Duplicate FetchedRecordZoneChanges & Sync Handling Questions
Hi everyone, I've recently implemented CKSyncEngine in my app, and I have two questions regarding its behavior: Duplicate FetchedRecordZoneChanges After Sending Changes: I’ve noticed that the engine sometimes receives a FetchedRecordZoneChanges event containing modifications and deletions that were just sent by the same device a few moments earlier. This event arrives after the SentRecordZoneChanges event, and both events share the same recordChangeTag, which results in double-handling the record. Is this expected behavior? I’d like to confirm if this is how CKSyncEngine works or if I might be overlooking something. Handling Initial Sync with a "Sync Screen": When a user opens the app for the first time and already has data stored in iCloud, I need to display a "Sync Screen" temporarily to prevent showing partial data or triggering abrupt, rapid UI changes. I’ve found that canceling current operations, then awaiting sendChanges() and fetchChanges() works well to ensure data is fully synced before dismissing the sync screen: displaySyncScreen = true await syncEngine.cancelOperations() try await syncEngine.sendChanges() try await syncEngine.fetchChanges() displaySyncScreen = false However, I’m unsure if canceling operations like this could lead to data loss or other issues. Is this a safe approach, or would you recommend a better strategy for handling this initial sync state?
1
0
607
Feb ’25