The app works on a local db but when I try to make it work with iCloud I get errors that I don't understand. CoreData+CloudKit: -[NSCloudKitMirroringDelegate _performSetupRequest:]_block_invoke(1247): <NSCloudKitMirroringDelegate: 0x10664c200>: Failed to set up CloudKit integration for store: <NSSQLCore: 0x106688140> (URL: file:///var/mobile/Containers/Data/Application/20EF350F-F0FA-4132-97DA-61B60AADB101/Library/Application%20Support/default.store) <CKError 0x109430e40: "Partial Failure" (2/1011); "Failed to modify some record zones"; uuid = 82ED152A-D015-414D-BB79-AF36E5AF4A8B; container ID = "iCloud.se.Grindegard.MinaRecept"; partial errors: { com.apple.coredata.cloudkit.zone:defaultOwner = <CKError 0x109431230: "Permission Failure" (10/2007); server message = "Invalid bundle ID for container"; op = E56A3CDA393641F8; uuid = 82ED152A-D015-414D-BB79-AF36E5AF4A8B> }> what can be wrong?

Greetings my fellow engineers, I use SwiftData in my iOS app. The schema is unversioned and consists of a single model. I've been modifying the model for almost two years now and relying on automatic database migrations. I had no problems for all that time, but now trying to add a property to the model or even remove a property from the model results in an error which seems like SwiftData is no longer capable of performing an automatic migration. The log console has things like the following: CoreData: error: NSUnderlyingError : Error Domain=NSCocoaErrorDomain Code=134190 "(null)" UserInfo={reason=Each property must have a unique renaming identifier} CoreData: error: reason : Can't find or automatically infer mapping model for migration CoreData: error: storeType: SQLite CoreData: error: configuration: default CoreData: annotation: options: CoreData: annotation: NSMigratePersistentStoresAutomaticallyOption : 1 CoreData: annotation: NSInferMappingModelAutomaticallyOption : 1 CoreData: annotation: NSPersistentStoreRemoteChangeNotificationOptionKey : 1 CoreData: annotation: NSPersistentHistoryTrackingKey : 1 CoreData: error: <NSPersistentStoreCoordinator: 0x7547b5480>: Attempting recovery from error encountered during addPersistentStore: 0x753f8d800 Error Domain=NSCocoaErrorDomain Code=134140 "Persistent store migration failed, missing mapping model." Have you ever encountered such an issue? What are my options?

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

I'm seeing a critical issue where a custom CKRecordZone is consistently deleted server-side when a second iCloud account interacts with a zone-wide CKShare. I've reproduced this 20+ times across two days and have exhausted every client-side fix I can think of. Looking for guidance on what might be going wrong. Setup Container: iCloud.com.cohencooks (production app on App Store) Custom CKRecordZone in owner's private database Zone-wide CKShare(recordZoneID:) (iOS 15+ zone sharing) SwiftData with ModelConfiguration(cloudKitDatabase: .none) — no automatic CloudKit mirroring Acceptance via CKFetchShareMetadataOperation → CKContainer.accept(metadata) (no UICloudSharingController) Minimal reproduction // 1. Owner creates zone + share let zone = CKRecordZone(zoneName: "MyZone") try await privateDB.save(zone) let share = CKShare(recordZoneID: zone.zoneID) share[CKShare.SystemFieldKey.title] = "My Share" as CKRecordValue share.publicPermission = .readWrite let (results, _) = try await privateDB.modifyRecords(saving: [share], deleting: []) // 2. Owner pushes ~500 records to zone — all succeed // 3. Second user (different iCloud account) accepts share let metadata = try await container.shareMetadata(for: shareURL) try await container.accept(metadata) // 4. Owner's next CKFetchRecordZoneChangesOperation → zoneNotFound (code 26) // Zone is permanently gone. allRecordZones() confirms deletion. What I observe Three distinct failure patterns depending on configuration: Pattern 1 — publicPermission = .readWrite, no addParticipant: Zone dies instantly after acceptance. First push notification shows cloudkit.share changed (zone alive), second push notification returns zoneNotFound. The non-owner never successfully wrote anything. Pattern 2 — publicPermission = .none with explicit addParticipant: Zone survives acceptance and 2-3 minutes of bidirectional sync (non-owner pulls 578 records, pushes meal plans back). Then a push notification arrives and the zone is gone. This is dramatically better than Pattern 1 but still fails. Pattern 3 — Container destabilization after repeated testing: After 20+ create/delete cycles in one day, zones die from the owner's own push notifications — no second device involved at all. The container appears to enter an unstable state. What I've ruled out Hypothesis Test Result publicPermission = .readWrite Changed to .none + explicit addParticipant Zone survived longer but still eventually deleted Zone name tombstoning Tested 6 fresh names never used in this container All eventually deleted Non-owner writes causing deletion Gated ALL non-owner push methods (recipe, meal plan, grocery, photo, event) Zone still deleted database.save(share) vs modifyRecords Switched to modifyRecords(saving:deleting:) Zone still deleted NSPersistentCloudKitContainer interference Removed all Core Data CloudKit code Zone still deleted Double share acceptance Fresh app install, single acceptance only Zone still deleted Advanced Data Protection Neither account has ADP enabled Not the cause Programmatic vs system acceptance Tested both container.accept() and tapping share link Zone still deleted CloudKit Dashboard No ZoneDelete operation is visible in the logs. All operations are ZoneFetch, ZoneChanges, RecordQuery, RecordFetch. I do see EphemeralGroup operations targeting the custom zone — not sure what generates those. Comparison with working apps I compared my implementation with another app (Spotbook) that uses the exact same zone-wide CKShare(recordZoneID:) pattern with publicPermission = .readWrite and programmatic acceptance — and it works. The main difference is that app uses CKSyncEngine (iOS 17+) rather than raw CKFetchRecordZoneChangesOperation / CKModifyRecordsOperation. Could CKSyncEngine be handling something internally that prevents this issue? Questions Is there a known interaction between zone-wide CKShare(recordZoneID:) acceptance and zone lifecycle that could cause zone deletion? Does CKSyncEngine handle zone-wide sharing differently than manual CKFetchRecordZoneChangesOperation + CKModifyRecordsOperation? What generates EphemeralGroup operations in CloudKit Dashboard? Could these trigger a zone delete? After 20+ zone create/delete cycles in a container, is there a server-side rate limit or tombstone mechanism that would destabilize new zones? Is the custom programmatic acceptance flow (CKFetchShareMetadataOperation → container.accept()) fully supported for zone-wide shares, or does it require UICloudSharingController? Any guidance would be greatly appreciated. This is blocking multi-user functionality for our app (mesa, a meal planning app on the App Store). Single-user sync works perfectly — the issue only manifests when a second iCloud account is involved. Environment: iOS 18.4.1, Xcode 16+, Swift, SwiftUI

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!

We’re using a private database with a custom zone. Record types and related schema are created programmatically rather than through the dashboard. When running the app in the development environment, I can see that data is saved and can be retrieved successfully. However, in the iCloud console, I don’t see any record types or even the custom zone. Additionally, I’m unable to deploy any schema to production because no changes are detected. Do you have any ideas on what we might be missing? Installing the app from TestFlight when trying to upload a record CloudKit reports this error: <CKError 0x13f40bb10: "Invalid Arguments" (12/2006); server message = "Cannot create new type MyType in production schema" ...>

Hi all I have a problem with core data, where when a new user login that is different from the previous user i delete all of core data by using "destroyPersistentStore". Then i recreate the persistent store, this works when i am testing. When it does not work for one of my users when she test. I am not sure why this should not work, i have added the code i use to destroy the persistent store below. This code is run after login but before the view changes away from my login view. // Retrieves the shared `AppDelegate` instance guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else { return } appDelegate.destroyDataSyncBackground() // Get a reference to a NSPersistentStoreCoordinator let storeContainer = appDelegate.persistentContainer.persistentStoreCoordinator // Delete each existing persistent store for store in storeContainer.persistentStores { if let url = store.url { do { try storeContainer.destroyPersistentStore( at: url, ofType: store.type, options: nil ) } catch { print("Failed to deleted all") } } else { print("Failed to deleted all") } } // Re-create the persistent container appDelegate.persistentContainer = NSPersistentContainer( name: "CueToCue" // the name of // a .xcdatamodeld file ) // Calling loadPersistentStores will re-create the // persistent stores appDelegate.persistentContainer.loadPersistentStores { (store, error) in // Handle errors let description = NSPersistentStoreDescription() description.shouldMigrateStoreAutomatically = true description.shouldInferMappingModelAutomatically = true appDelegate.persistentContainer.persistentStoreDescriptions = [description] } // Reapply context configuration let viewContext = appDelegate.persistentContainer.viewContext viewContext.automaticallyMergesChangesFromParent = true viewContext.mergePolicy = NSMergeByPropertyObjectTrumpMergePolicy do { try viewContext.save() appDelegate.recreateDataSyncBackground() } catch { print("Debug: saving delete all failed.") } } The function "destroyDataSyncBackground" just set the my sync class to nil so stop any changes to core data while the code is running. The function "recreateDataSyncBackground" recreate the sync class so fetch, post and patch requests is made again.

I am following Apple's instruction to sync SwiftData with CloudKit. While initiating the ModelContainer, right after removing the store from Core Data, the error occurs: FAULT: NSInternalInconsistencyException: This NSPersistentStoreCoordinator has no persistent stores (unknown). It cannot perform a save operation.; (user info absent) I've tried removing default.store and its related files/folders before creating the ModelContainer with FileManager but it does not resolve the issue. Isn't it supposed to create a new store when the ModelContainer is initialized? I don't understand why this error occurs. Error disappears when I comment out the #if DEBUG block. Code: import CoreData import SwiftData import SwiftUI struct InitView: View { @Binding var modelContainer: ModelContainer? @Binding var isReady: Bool @State private var loadingDots = "" @State private var timer: Timer? var body: some View { VStack(spacing: 16) { Text("Loading\(loadingDots)") .font(.title2) .foregroundColor(.gray) } .padding() .onAppear { startAnimation() registerTransformers() let config = ModelConfiguration() let newContainer: ModelContainer do { #if DEBUG // Use an autorelease pool to make sure Swift deallocates the persistent // container before setting up the SwiftData stack. try autoreleasepool { let desc = NSPersistentStoreDescription(url: config.url) let opts = NSPersistentCloudKitContainerOptions(containerIdentifier: "iCloud.my-container-identifier") desc.cloudKitContainerOptions = opts // Load the store synchronously so it completes before initializing the // CloudKit schema. desc.shouldAddStoreAsynchronously = false if let mom = NSManagedObjectModel.makeManagedObjectModel(for: [Page.self]) { let container = NSPersistentCloudKitContainer(name: "Pages", managedObjectModel: mom) container.persistentStoreDescriptions = [desc] container.loadPersistentStores { _, err in if let err { fatalError(err.localizedDescription) } } // Initialize the CloudKit schema after the store finishes loading. try container.initializeCloudKitSchema() // Remove and unload the store from the persistent container. if let store = container.persistentStoreCoordinator.persistentStores.first { try container.persistentStoreCoordinator.remove(store) } } // let fileManager = FileManager.default // let sqliteURL = config.url // let urls: [URL] = [ // sqliteURL, // sqliteURL.deletingLastPathComponent().appendingPathComponent("default.store-shm"), // sqliteURL.deletingLastPathComponent().appendingPathComponent("default.store-wal"), // sqliteURL.deletingLastPathComponent().appendingPathComponent(".default_SUPPORT"), // sqliteURL.deletingLastPathComponent().appendingPathComponent("default_ckAssets") // ] // for url in urls { // try? fileManager.removeItem(at: url) // } } #endif newContainer = try ModelContainer(for: Page.self, configurations: config) // ERROR!!! } catch { fatalError(error.localizedDescription) } modelContainer = newContainer isReady = true } .onDisappear { stopAnimation() } } private func startAnimation() { timer = Timer.scheduledTimer( withTimeInterval: 0.5, repeats: true ) { _ in updateLoadingDots() } } private func stopAnimation() { timer?.invalidate() timer = nil } private func updateLoadingDots() { if loadingDots.count > 2 { loadingDots = "" } else { loadingDots += "." } } } import CoreData import SwiftData import SwiftUI @main struct MyApp: App { @State private var modelContainer: ModelContainer? @State private var isReady: Bool = false var body: some Scene { WindowGroup { if isReady, let modelContainer = modelContainer { ContentView() .modelContainer(modelContainer) } else { InitView(modelContainer: $modelContainer, isReady: $isReady) } } } }

When deleting a SwiftData entity, I sometimes encounter the following error in a document based SwiftUI app: Fatal error: Unexpected backing data for snapshot creation: SwiftData._FullFutureBackingData<MyEntityClass> The deletion happens in a SwiftUI View and the code used to retrieve the entity is standard (the ModelContext is injected from the @Environment): let myEntity = modelContext.model(for: entityIdToDelete) modelContext.delete(myEntity) Unfortunately, I haven't yet managed to isolate this any further in order to come up with a reproducible PoC. Could you give me further information about what this error means?

Hello, thank you Apple for supporting custom store with SwiftData and the Schema type is superb to work with. I have successfully set one up with SQL and have some feedback and issues regarding its APIs. There’s a highlighted message in the documentation about not using internal restricted symbols directly, but they contradict with the given protocols and I am concerned about breaking any App Store rules. Are we allowed to use these? If not, they should be opened up as they’re useful. BackingData is required to set up custom snapshots, initialization, and getting/setting values. And I want to use it with createBackingData() to directly initialize instances from snapshots when transferring them between server and client or concurrency. RelationshipCollection for casting to-many relationships from backing data or checking if an array contains a PersistentModel. SchemaProperty for type erasure in a collection. Schema.Relationship has KeyPath properties, but it is missing for Schema.Attribute and Schema.CompositeAttribute. Which means you can’t purely depend on the schema to map data. I am unable to access the properties of a custom struct type in a predicate unless I use Mirror with schemaMetadata() or CustomStringConvertible on the KeyPath directly to extract it. Trivial, but… the KeyPath property name is inconsistent (it’s all lowercase). It would be nice to retrieve property names from custom struct types, since you are unable access CodingKeys that are auto synthesized by Codable for structs. But I recently realized they’re a part Schema.CompositeAttribute, however I don’t know how to match these without the KeyPath… I currently map my entities using CodingKeys to their PredicateCodableKeyPathProviding.… but I wish for a simpler alternative! It’s unclear how to provide the schema to the snapshot before new models are created. I currently use a static property, but I want to make it flexible if more schemas and configurations are added later on. I considered saving and loading the schema in a temporary location, but doubtful that the KeyPath values will be available as they are not Codable. I suspect schemaMetadata() has the information I need to map the backing data without a schema for snapshots, but as mentioned previously, properties are inaccessible… Allow access to entity metatypes, like value types from SchemaProperty. They’re useful for getting data out of snapshots and casting them to CodingKeys and PredicateCodableKeyPathProviding. They do not carry over when you provide them in the Schema. I am unable to retrieve the primary key from PersistentIdentifier. It seems like once you create one, you can’t get it out, like the DataStoreConfiguration in ModelContainer is not the one you used to set it up. I cannot cast it, it is an entirely different struct? I have to use JSONSerialization to extract it, but I want to get it directly since it is not a column in my database. It is transformed when it goes to/from my tables. It’s unknown how to support some schema options, such as Spotlight and CloudKit. Allow for extending macro options, such as adding options to set as primary key, whether to auto increment, etc… You can create a schema for super and sub entities, but it doesn’t appear you can actually set them up from the @Model macro or use inheritance on these models… SwiftData history tracking seems incomplete for HistoryDelete, because that protocol requires HistoryTombstone, but this type cannot be instantiated, nor does it contain anything useful to infer from. As an aside, I want to create my own custom ModelActor that is a global actor. However, I’m unable to replicate the executor that Apple provides where the executor has a ModelContext, because this type does not conform to Sendable. So how did Apple do this? The documentation doesn’t mention unchecked Sendable, but I figure if the protocol is available then we would be able to set up our own. And please add concurrency features! Anyway, I hope for more continued support in the future and I am looking forward to what’s new this WWDC! 😊

Hi, I'm having trouble implementing iCloud Drive in my app. I've already taken the obvious steps, including enabling iCloud Documents in Xcode and selecting a container. This container is correctly specified in my code, and in theory, everything should work. The data generated by my app should be saved to iCloud Drive in addition to local storage. The data does get stored in the Files app, but the automatic syncing to iCloud Drive doesn’t work as expected. I’ve also considered updating my .entitlements file. Since I’m at a loss, I’m reaching out for help maybe I’ve overlooked something important that's causing it not to work. If anyone has an idea, please let me know. Thanks in advance!

If Cloudkit is enabled, SwiftData @Query operation hangs when the View scenePhase becomes active. Seems like the more @Query calls you have, the more it hangs. This has been first documented some time ago, but in typical Apple style, it has not been addressed or even commented on. https://developer.apple.com/forums/thread/761434

Hello, In our app, we’ve modeled our schema using inheritance introduced in iOS 26.0, and we’re implementing SwiftData History to re-fetch models only when necessary. @Model public class Transaction { @Attribute(.preserveValueOnDeletion) public var date: Date = Date() public var amount: Double = 0 public var memo: String? } @Model public final class Spending: Transaction { public var installmentIndex: Int = 1 public var installment: Int = 1 public var installmentID: UUID? } If data has been deleted from database, we need to check a date property to determine whether to re-fetch datas. To do this, we added the preserveValueOnDeletion attribute to date property so we could retrieve it from the History tombstone value. However, after adding this attribute, a crash occurs. There is a console log Could not cast value of type 'Swift.ReferenceWritableKeyPath<Shared.ModelSchemaV5.Transaction, Foundation.Date>' (0x106bf8328) to 'Swift.PartialKeyPath<Shared.ModelSchemaV5.Spending>' (0x1094f21d8). and error log attached StrictMoneyChecking-2025-11-07-105108.txt I also tried this in the recent SampleTrip app, and fetching all history after a deletion causes the same crash. Is this issue currently being worked on or under investigation?

Greetings i have an app that uses three different SwiftData models and i want to know what is the best way to use the them accross the app. I though a centralized behaviour and i want to know if it a correct approach.First let's suppose that the first view of the app will load the three models using the @Enviroment that work with @Observation. Then to other views that add data to the swiftModels again with the @Environment. Another View that will use the swiftData models with graph and datas for average and min and max.Is this a corrent way? or i should use @Query in every view that i want and ModelContext when i add the data. @Observable class CentralizedDataModels { var firstDataModel: [FirstDataModel] = [] var secondDataModel: [SecondDataModel] = [] var thirdDataModel: [ThirdDataModel] = [] let context: ModelContext init(context:ModelContext) { self.context = context } }

I'm writing some tests to confirm the behavior of my app. White creating a model actor to delete objects I realized that ModelContext.model(for:) does return objects that are deleted. I was able to reproduces this with this minimal test case: @Model class Activity { init() {} } struct MyLibraryTests { let modelContainer = try! ModelContainer( for: Activity.self, configurations: ModelConfiguration( isStoredInMemoryOnly: true ) ) init() throws { let context = ModelContext(modelContainer) context.insert(Activity()) try context.save() } @Test func modelForIdAfterDelete() async throws { let context = ModelContext(modelContainer) let id = try context.fetch(FetchDescriptor<Activity>()).first!.id context.delete(context.model(for: id) as! Activity) try context.save() let result = context.model(for: id) as? Activity #expect(result == nil) // Expectation failed: (result → MyLibrary.Activity) == nil } @Test func fetchDescriptorAfterDelete() async throws { let context = ModelContext(modelContainer) let id = try context.fetch(FetchDescriptor<Activity>()).first!.id context.delete(context.model(for: id) as! Activity) try context.save() let result = try context.fetch( FetchDescriptor<Activity>(predicate: #Predicate { $0.id == id }) ).first #expect(result == nil) } } Here I create a new context, insert an model and save it. The test modelForIdAfterDelete does fail, as result still contains the deleted object. I also tried to check #expect(result!.isDeleted), but it is also false. With the second test I use a FetchDescriptor to retrieve the object by ID and it correctly returns nil. Shouldn't both methods use a consistent behavior?

Hey everyone, I have a question. When creating an app, how should I design a message table that involves personal privacy? The content is stored locally on the user's device, and then encrypted in the server database? How should I design it?

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,

Hi ! Would anyone know (if possible) how to create backup files to export and then import from the data recorded by SwiftData? For those who wish, here is a more detailed explanation of my case: I am developing a small management software with customers and events represented by distinct classes. I would like to have an "Export" button to create a file with all the instances of these 2 classes and another "Import" button to replace all the old data with the new ones from a previously exported file. I looked for several solutions but I'm a little lost...

Hi all, In my SwiftUI / SwiftData / Cloudkit app which is a series of lists, I have a model object called Project which contains an array of model objects called subprojects: final class Project1 { var name: String = "" @Relationship(deleteRule: .cascade, inverse: \Subproject.project) var subprojects : [Subproject]? init(name: String) { self.name = name self.subprojects = [] } } The user will select a project from a list, which will generate a list of subprojects in another list, and if they select a subproject, it will generate a list categories and if the user selects a category it will generate another list of child objects owned by category and on and on. This is the pattern in my app, I'm constantly passing arrays of model objects that are the children of other model objects throughout the program, and I need the user to be able to add and remove things from them. My initial approach was to pass these arrays as bindings so that I'd be able to mutate them. This worked for the most part but there were two problems: it was a lot of custom binding code and when I had to unwrap these bindings using init?(_ base: Binding<Value?>), my program would crash if one of these arrays became nil (it's some weird quirk of that init that I don't understand at al). As I'm still learning the framework, I had not realized that the @model macro had automatically made my model objects observable, so I decided to remove the bindings and simply pass the arrays by reference, and while it seems these references will carry the most up to date version of the array, you cannot mutate them unless you have access to the parent and mutate it like such: project.subcategories?.removeAll { $0 == subcategory } project.subcategories?.append(subcategory) This is weirding me out because you can't unwrap subcategories before you try to mutate the array, it has to be done like above. In my code, I like to unwrap all optionals at the moment that I need the values stored in them and if not, I like to post an error to the user. Isn't that the point of optionals? So I don't understand why it's like this and ultimately am wondering if I'm using the correct design pattern for what I'm trying to accomplish or if I'm missing something? Any input would be much appreciated! Also, I do have a small MRE project if the explanation above wasn't clear enough, but I was unable to paste in here (too long), attach the zip or paste a link to Google Drive. Open to sharing it if anyone can tell me the best way to do so. Thanks!