public static func fetch(in context: NSManagedObjectContext, configurationBlock: (NSFetchRequest) -> () = { _ in }) -> [Self] { let request = NSFetchRequest(entityName: Self.entityName) configurationBlock(request) return try! context.fetch(request) } context.fetch(request), 'fetch' function has error. Thread 24: EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0)

After a recent iOS update, my app is not synching between devices. I'm not seeing or getting any errors. CLoudKit Logs show activity, but it's not happening realtime. Even if I close and reopen the app, it won't sync between devices. It almost looks like it only has local storage now and CloudKit is not working on it anymore. STEPS TO REPRODUCE Use app on two devices with the same Apple ID. Create a user and one device and it won't show up on the other device. Vice Versa.

Background: Our non-production App was using SwiftData locally. Yesterday we followed the documentation to enable CloudKit: https://developer.apple.com/documentation/cloudkit/enabling-cloudkit-in-your-app iCloud Works: Data is properly syncing via iCloud between 2 devices. Add on one shows on the other; delete on one deletes on the other. Today we logged into CloudKit Console for the first time; but there are no databases showing. We verified: Users and Roles: we have “Access to Cloud Managed… Certificates” Certificates, Identifiers & Profiles: our app has iCloud capabilities and is using our iCloud Container Signed into CloudKit Console with same developer ID as AppStoreConnect This is also the Apple ID of the iCloud account that has synced data from our app. In Xcode > Signing & Capabilities we are signed in as our Company team. Any guidance or tips to understanding how to what’s going on in CloudKit Console and gaining access to the database is appreciated!

Hello, our application works with Core Data to save some datas about its activity. We have background Tasks implemented and our app execution in background shows this error message in the Logs: error: Failed to acquire background task assertion for task 'CoreData: Executing write request'. Anyone could explain what this message means? Could it be that NSManagedObjectContext changes might not be written?

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?

Is it possible to track history using the new HistoryDescriptor feature in SwiftData? Or can I only get the current most recent data? Or is it possible to output the changed data itself, along with timestamps? I am hoping that it is possible to track by a standard feature like NSPersistentHistoryTransaction in CoreData. Do we still have to use a method in SwiftData that creates more tracking data itself?

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!

Is there a way to move user data from UserDefaults to SwiftData when the app is in production so that people don’t lose their data. Currently my audio journals in my journal app has everything in the UserDefaults. Now this is bad for obvious reasons but I was thinking if there was a way. It’s only been 1 week since published and I have already had17 people download it.

Hi Developer Community, I'm experiencing a critical issue with CloudKit schema deployment that's blocking my app release. I've been trying to resolve this for several days and would appreciate any assistance from the community or Apple engineers. Issue Description I'm unable to deploy my CloudKit schema from development to production environment. When attempting to deploy through the CloudKit Dashboard, I either get an "Internal Error" message or the deployment button is disabled. Environment Details App: Reef Trak (Reef aquarium tracking app) CloudKit Container: ************ Development Environment: Schema fully defined and working correctly Production Environment: No schema deployed (confirmed in dashboard) What I've Tried Using the "Deploy Schema to Production" button in CloudKit Dashboard (results in "Internal Error") Exporting schema from development and importing to production (fails) Using CloudKit CLI tools with API token (results in "invalid-scope" errors) Waiting 24-48 hours between attempts in case of propagation delays Current Status App works perfectly in development environment (when run from Xcode) In TestFlight/sideloaded builds (production environment), the app attempts to fetch records but fails with "Did not find record type: Tank" errors Log snippet showing the issue: [2025-03-21] [CloudKit] Schema creation failed: Error saving record <CKRecordID: 0x******; recordName=SchemaSetup_Tank_-**---****, zoneID=_defaultZone:defaultOwner> to server: Cannot create new type Tank in production schema [2025-03-21] [CloudKit] Failed to create schema for Tank after 3 attempts [2025-03-21] [CloudKit] Error creating schema for Tank: Error saving record <CKRecordID: 0x****; recordName=SchemaSetup_Tank_---**-**********, zoneID=_defaultZone:defaultOwner> to server: Cannot create new type Tank in production schema App Architecture & Critical Impact My app "Reef Trak" is built around a core data model where the "Tank" entity serves as the foundational element of the entire application architecture. The Tank entity is not just another data type - it's the primary container that establishes the hierarchical relationship for all other entities: All parameter measurements (pH, temperature, salinity, etc.) are associated with specific tanks All maintenance tasks and schedules are tank-specific All livestock (fish, corals, invertebrates) exist within the context of a tank All user achievements and progress tracking depend on tank-related activities Without the Tank schema being properly deployed to production, users experience what appears to be a completely empty application, despite successful authentication and CloudKit connection. The app shows "Successfully retrieved iCloud data" but displays no content because: The Tank record type doesn't exist in production Without Tanks, all child entities (even if their schemas existed) have no parent to associate with This creates a cascading failure where no data can be displayed or saved This issue effectively renders the entire application non-functional in production, despite working flawlessly in development. Users are left with an empty shell of an app that cannot fulfill its core purpose of reef tank management and monitoring. The inability to deploy the Tank schema to production is therefore not just a minor inconvenience but a complete blocker for the app's release and functionality. Questions Is there an alternative method to deploy schema to production that I'm missing? Could there be an issue with my account permissions or container configuration? Are there known issues with the CloudKit Dashboard deployment functionality? What's the recommended approach when the dashboard deployment fails? I've also submitted a Technical Support Incident, but I'm hoping to get this resolved quickly as it's blocking my App Store release. Thank you for any assistance!

Hi! I believe there might be a small bug in the SwiftData Quakes Sample App.^1 The Quakes app requests a JSON feed from USGS.^2 What seems to be breaking is that apparently earthquake entities from USGS can return with null magnitudes. That is throwing errors from the decoder: struct GeoFeatureCollection: Decodable { let features: [Feature] struct Feature: Decodable { let properties: Properties let geometry: Geometry struct Properties: Decodable { let mag: Double let place: String let time: Date let code: String } struct Geometry: Decodable { let coordinates: [Double] } } } which is expecting mag to not be nil. Here is my workaround: struct GeoFeatureCollection: Decodable { let features: [Feature] struct Feature: Decodable { let properties: Properties let geometry: Geometry struct Properties: Decodable { let mag: Double? let place: String let time: Date let code: String } struct Geometry: Decodable { let coordinates: [Double] } } } And then: extension Quake { /// Creates a new quake instance from a decoded feature. convenience init(from feature: GeoFeatureCollection.Feature) { self.init( code: feature.properties.code, magnitude: feature.properties.mag ?? 0.0, time: feature.properties.time, name: feature.properties.place, longitude: feature.geometry.coordinates[0], latitude: feature.geometry.coordinates[1] ) } }

There's some logic in my app that first checks to see if a specific CloudKit record zone exists. If it doesn't, it creates the zone, and then my application continues on with its work. The way I've implemented this right now is by catching the zoneNotFound error when I call CKDatabase#recordZone(for:) (docs) and creating the zone when that happens: do { try await db.recordZone(for: zoneID) } catch let ckError as CKError where [.zoneNotFound, .userDeletedZone].contains(ckError.code) { // createZone is a helper function try await createZone(zoneID: zoneID, context: context) } This works great, but every time I do this, an error is logged in CloudKit Console, which creates a lot of noise and makes it harder to see real errors. Is there a way to do this without explicitly triggering a CloudKit error? I just found CKDatabase#recordZones(for:) (docs), which seems like it returns an empty array instead of throwing an error if the zone doesn't exist. Will calling that and looking for a non-empty array work just as well, but without logging lots of errors in the console?

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 am encountering an issue with the UndoManager functionality in a SwiftUI application that integrates SwiftData for persistence. This issue occurs specifically in macOS 14 (Sonoma) but works as expected on macOS 15 (Sequoia). The focused test app I have prepared for demonstration allows users to create ParentItem objects, and for each ParentItem, users can add multiple ChildItem objects. The undo functionality (via Cmd+Z) is not working as expected in Sonoma. When I try to undo a ChildItem addition, the UndoManager does not revert just the last ChildItem added, but instead removes all ChildItems that were added in that session. Expected Behavior On macOS 14 (Sonoma), I expect the UndoManager to undo only the most recent transaction (in this case, a single ChildItem insert), similar to how it functions on macOS 15 (Sequoia). Each ChildItem insertion should be treated as a separate undoable action. Current Behavior In macOS Sonoma, pressing Cmd+Z undoes the entire list of ChildItems added to a ParentItem in the current session, rather than just the most recent ChildItem. This appears to be an issue with undo grouping, but I’ve confirmed that no explicit grouping is being used. Question Is this an issue with UndoManager in macOS Sonoma, particularly in how it interacts with SwiftData persistence? What changes should I make to ensure that each ChildItem insert is treated as an individual undo action in macOS Sonoma, just as it works in Sequoia? Any guidance on isolating the issue or recommended workarounds would be appreciated. I would expect that undo actions for each child addition would be treated as separate transactions, not grouped. Steps Taken to Solve the Problem I attempted to manually save the model context (modelContext.save()) after each ChildItem insert to ensure proper persistence. I also verified that UndoManager was not grouping operations explicitly by calling beginUndoGrouping() or endUndoGrouping() myself. This issue seems to be tied specifically to macOS Sonoma, as it does not occur on macOS Sequoia, where undoing behaves as expected. Conditions macOS 14 Sonoma: The issue occurs consistently. macOS 15 Sequoia: The issue does not occur. This issue appears to be independent of hardware, as I’ve tested it on multiple machines. APIs/Features Potentially Involved UndoManager in a SwiftUI application SwiftData for persistence (using modelContext.save()) macOS version-specific behavior Steps to reproduce Clone test project (https://github.com/Maschina/SwiftDataUndoManagerExample), compile and run Create a new ParentItem in the app (via plus toolbar button in the sidebar). Add multiple ChildItems to the ParentItem (via plus toolbar button in the content / middle column of the navigation split view). Press Cmd+Z to undo the last addition.

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.

I have transitioned to CKSyncEngine for syncing data to iCloud, and it is working quite well. I have a question regarding best practices for modifying and saving a CKRecord which already exists in the private or shared database. In my current app, most CKRecords will never be modified after saving to the database, so I do not persist a received record locally after updating my local data model. In the rare event that the local data for that record is modified, I manually fetch the associated server record from the database, modify it, and then use CKSyncEngine to save the modified record. As an alternative method, I can create a new CKRecord locally with the corresponding recordID and the modified data, and then use CKSyncEngine to attempt to save that record to the database. Doing so generates an error in the delegate method handleSentRecordZoneChanges, where I receive the local record I tried to save back inevent.failedRecordSaves with a .serverRecordChanged error, along with the corresponding server CKRecord. I can then update that server record with the local data and re-save using CKSyncEngine. I have not yet seen any issues when doing it this way. The advantage of the latter method is that CKSyncEngine handles the entire database operation, eliminating the manual fetch step. My question is: is this an acceptable practice, or could this result in other unforeseen issues?

I am developing an Xcode app with a job feed, with profile view, with chat eg. I fetch using federatet queries to my microservices thru Apollo Router. Infront of the Apollo Router i Have a Kong that adds a X user ID, that the microservices use for personalized feed and other user info. The info is stored with SwiftData. My thought is that i should add a better way of controlling when i need to fetch. I have a “lastupdateAPI” with different entities (profile, profile picture eg). So when nothing has changed we do not fetch. But rather then using a own API for this, isnt ETag better? Or is it any other recommendations with Xcode Swiftui. Good strategies for not fetching what i already have?

Does the CloudKit participant limit of 100 include the owner?

After the problems with the ModelActor in iOS 18, it seemed like the ModelActor became more stable with iOS 18.1 and macOS 15.1. However, I’m still encountering many problems and crashes. I wanted to ask if these issues are related to my persistence layer architecture or if they’re still inherent to the ModelActor itself. I’ve generally followed the blog posts: https://fatbobman.com/en/posts/practical-swiftdata-building-swiftui-applications-with-modern-approaches/ and https://brightdigit.com/tutorials/swiftdata-modelactor/ and aim to achieve the following: I have a single DataProvider that holds the ModelContainer and uses it to configure and initialize a single DataHandler. These are created once at app launch and injected into the SwiftUI view hierarchy as EnvironmentObjects. Since I need to access the SwiftData models not only in SwiftUI but also indirectly in ViewModels or UIKit views, all read operations on the models should go through the DataProvider ( ModelContainrs MainContext), while all other CRUD operations are handled centrally via the single DataHandler (executed within a single ModelActor). Additionally, I want to monitor the entire container using another ModelActor, initialized in the DataProvider, which tracks changes to objects using TransactionHistory. I’ve managed to implement this to some extent, but I’m facing two main issues: ModelActor and Main Actor Requirement The ModelActor only updates SwiftUI views when initialized via the main context of the ModelContainer and therefore runs on the Main Actor. It would be ideal for this to work in the background, but the issue with the ModelActor that existed previously doesn’t seem to have been resolved in iOS 18.1/macOS 15.1—am I wrong about this? Frequent Crashes (more severe) Crashes occur, especially when multiple windows on macOS or iPadOS access the same DataHandler to update models. This often leads to crashes during read operations on models by a SwiftUI view, with logs like: Object 0x111f15480 of class _ContiguousArrayStorage deallocated with non-zero retain count 3. This object's deinit, or something called from it, may have created a strong reference to self which outlived deinit, resulting in a dangling reference. error: the replacement path doesn't exist: "/var/folders/gs/8rwdjczj225d1pj046w3d97c0000gn/T/swift-generated-sources/@__swiftmacro_12SwiftDataTSI3TagC4uuID18_PersistedPropertyfMa_.swift" Can't show file for stack frame : <DBGLLDBStackFrame: 0x34d28e170> - stackNumber:1 - name:Tag.uuID.getter. The file path does not exist on the file system: /var/folders/gs/8rwdjczj225d1pj046w3d97c0000gn/T/swift-generated-sources/@__swiftmacro_12SwiftDataTSI3TagC4uuID18_PersistedPropertyfMa_.swift This error usually happens when there are multiple concurrent accesses to the DataHandler/ModelActor. However, crashes also occur sporadically during frequent accesses from a single view with an error like "the replacement path doesn't exist." It also seems like having multiple ModelActors, as in this case (one for observation and one for data changes), causes interference and instability. The app appears to crash less frequently when the observer is not initialized, but I can’t verify this—it might just be a coincidence. My Question: Am I fundamentally doing something wrong with the ModelActors or the architecture of my persistence layer?

I'm a first time developer for Swift, (getting on a bit!) but after programming in VB back in the late 90s I wanted to write an app for iPhone. I think I might have gone about it the wrong way, but I've got an app that works great on my iPhone or works great on my iPad. It saves the data persistently on device, but, no matter how much I try, what I read and even resorting to AI (ChatGPT & Gemini) I still can't get it to save the data on iCloud to synchronise between the two and work across the devices. I think it must be something pretty fundamental I'm doing (or more likely not doing) that is causing the issue. I'm setting up my signing and capabilities as per the available instructions but I always get a fatal error. I think it might be something to do with making fields optional, but at this point I'm second guessing myself and feeling a complete failure. Any advice or pointers would be really gratefully appreciated. I like my app and would like eventually to get it on the App Store but at this point in time I feel it should be on the failed projects heap! I've even tried a new Xcode project for iOS and asking it to use SwiftData and CloudKit - the default project should work - right? But it absolutely doesn't for me. Please send help!!

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.