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.
iCloud & Data
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I have a widely-used app that lets users keep track of personal data. This data is persisted with SwiftData, and synced with CloudKit.
I understand that if the user's iCloud account changes on a device (for example, user logs out or toggles off an app's access to iCloud), then NSPersistentCloudKitContainer will erase the local data records on app launch. This is intentional behavior, intended as a privacy feature.
However, we are receiving regular reports from users for whom the system has incorrectly indicated that the app's access to iCloud is unavailable, even when the user hasn't logged out or toggled off permission to access iCloud. This triggers the behavior to clear the local records, and even though the data is still available in iCloud, to the user, it looks like their data has disappeared for no reason. Helping the user find and troubleshoot their iCloud app data settings can be very difficult, since in many cases the user has no idea what iCloud is, and we can't link them directly to the correct settings screen.
We seem to get these reports most frequently from users whose iCloud storage is full (which feels like punishment for not paying for additional storage), but we've also received reports from users who have enough storage space available (and are logged in and have the app's iCloud data permissions toggled on). It appears to happen randomly, as far as we can tell.
I found a blog post from two years ago from another app developer who encountered the same issue: https://crunchybagel.com/nspersistentcloudkitcontainer/#:~:text=The%20problem%20we%20were%20experiencing
To work around this and improve the user experience, we want to use CKContainer.accountStatus to check if the user has an available iCloud account, and if not, disable the CloudKit sync before it erases the local data.
I've found steps to accomplish this workaround using CoreData, but I'm not sure how to best modify the ModelContainer's configuration after receiving the CKAccountStatus when using SwiftData. I've put together this approach so far; is this the right way to handle disabling/enabling sync based on account status?
import SwiftUI
import SwiftData
import CloudKit
@main
struct AccountStatusTestApp: App {
@State private var modelContainer: ModelContainer?
var body: some Scene {
WindowGroup {
if let modelContainer {
ContentView()
.modelContainer(modelContainer)
} else {
ProgressView("Loading...")
.task {
await initializeModelContainer()
}
}
}
}
func initializeModelContainer() async {
let schema = Schema([
Item.self,
])
do {
let accountStatus = try await CKContainer.default().accountStatus()
let modelConfiguration = ModelConfiguration(
schema: schema,
cloudKitDatabase: accountStatus == .available ? .private("iCloud.com.AccountStatusTestApp") : .none
)
do {
let container = try ModelContainer(for: schema, configurations: [modelConfiguration])
modelContainer = container
} catch {
print("Could not create ModelContainer: \(error)")
}
} catch {
print("Could not determine iCloud account status: \(error)")
}
}
}
I understand that bypassing the clearing of local data when the iCloud account is "unavailable" introduces possible issues with data being mingled on shared devices, but I plan to mitigate that with warning messages when users are in this state. This would be a far more preferable user experience than what's happening now.
Topic:
App & System Services
SubTopic:
iCloud & Data
Does the CloudKit participant limit of 100 include the owner?
Hi everyone,
Complete newbie here. Building an app and trying to use Cloudkit. I've added the CloudKit capability, triple checked the entitlements file for appropriate keys, made sure the code signing entitlements are pointing to the correct entitlements file. I've removed and cleared all of those settings and even created a new container as well as refreshed the signing. I just can't seem to figure out why I keep getting this error:
Significant issue at CKContainer.m:747: In order to use CloudKit, your process must have a com.apple.developer.icloud-services entitlement. The value of this entitlement must be an array that includes the string "CloudKit" or "CloudKit-Anonymous".
Any guidance is greatly appreciated.
In the CloudKit logs I see logs that suggest users getting QUOTA_EXCEEDED error for RecordDelete operations.
{
"time":"21/07/2025, 7:57:46 UTC"
"database":"PRIVATE"
"zone":"***"
"userId":"***"
"operationId":"***"
"operationGroupName":"2.3.3(185)"
"operationType":"RecordDelete"
"platform":"iPhone"
"clientOS":"iOS;18.5"
"overallStatus":"USER_ERROR"
"error":"QUOTA_EXCEEDED"
"requestId":"***"
"executionTimeMs":"177"
"interfaceType":"NATIVE"
"recordInsertBytes":54352
"recordInsertCount":40
"returnedRecordTypes":"_pcs_data"
}
I'm confused as to what this means? Why would a RecordDelete operation have recordInsertBytes? I'd expect a RecordDelete operation to never fail on quotaExceeded and how would I handle that in the app?
I've got an application built on top of SwiftData (+ CloudKit) which is published to App Store.
I've got a problem where on each app update, the data saved in the database is duplicated to the end user.
Obviously this isn't wanted behaviour, and I'm really looking forward to fixing it. However, given the restrictions of SwiftData, I haven't found a single fix for this.
The data duplication happens automatically on the first initial sync after the update. My guess is that it's because it doesn't detect the data already in the device, so it pulls all data from iCloud and appends it to the database where data in reality exists.
error: the replacement path doesn't exist <- how bad is this error, should i care - is it important?
I get this error, i have my own DIKit, and i want to use swiftdata for showing info from persisten model. It works all over the app, but i get this error with my .sheet.
// JobCreationView.swift
// Features
//
// Created by Jens Vik on 26/03/2025.
//
import SwiftUI
import DesignKit
import DIKit
import PresentationKit
import CoreKit
import DomainKit
import SwiftData
public struct JobCreationView: View {
@Binding var isPresented: Bool
// Inject view model using DIKit's property wrapper
@Injected((any JobCreationViewModelProtocol).self) private var viewModel
// Form state
@Injected(ModelContext.self) private var modelContext
@State private var date = Date()
@State private var isASAP = false
@State private var price = ""
@State private var jobType = "Fiks"
@State private var description = ""
// Available job types
private let jobTypes = ["Fiks", "Fiksit"]
@Query private var userContexts: [UserContextModel]
public init(isPresented: Binding<Bool>) {
self._isPresented = isPresented
print("DEBUG: JobCreationView initialized")
}
public var body: some View {
let city = userContexts.first?.city ?? "Loading..."
NavigationView {
Form {
Section(header: Text("Location")) {
Text(city)
}
Section(header: Text("Details")) {
TextField("Price", text: $price)
.keyboardType(.numberPad)
Picker("Job Type", selection: $jobType) {
ForEach(jobTypes, id: \.self) { type in
Text(type).tag(type)
}
}
.pickerStyle(SegmentedPickerStyle())
TextEditor(text: $description)
.frame(minHeight: 100)
.overlay(
RoundedRectangle(cornerRadius: 8)
.stroke(Color.gray.opacity(0.2), lineWidth: 1)
)
}
}
.navigationBarTitle("Create Job", displayMode: .inline)
.navigationBarItems(
leading: Button("Cancel") {
isPresented = false
},
trailing: Button("Post") {
// Post functionality will be added later
isPresented = false
}
.disabled( (!isASAP && date < Date()) || price.isEmpty || description.isEmpty)
)
}
}
}
How bad is this macro error?
error: the replacement path doesn't exist: "/var/folders/dn/x3x4wwkd335_rl91by3tqx5w0000gn/T/swift-generated-sources/@_swiftmacro_10FeatureKit15JobCreationViewV12userContexts33_CDDE5BE156468A2E8CC9B6A7E34B1006LL5QueryfMa.swift"
error: the replacement path doesn't exist: "/var/folders/dn/x3x4wwkd335_rl91by3tqx5w0000gn/T/swift-generated-sources/@_swiftmacro_10FeatureKit15JobCreationViewV12userContexts33_CDDE5BE156468A2E8CC9B6A7E34B1006LL5QueryfMa.swift"
error: the replacement path doesn't exist: "/var/folders/dn/x3x4wwkd335_rl91by3tqx5w0000gn/T/swift-generated-sources/@_swiftmacro_10FeatureKit15JobCreationViewV12userContexts33_CDDE5BE156468A2E8CC9B6A7E34B1006LL5QueryfMa.swift"
error: the replacement path doesn't exist: "/var/folders/dn/x3x4wwkd335_rl91by3tqx5w0000gn/T/swift-generated-sources/@_swiftmacro_10FeatureKit15JobCreationViewV12userContexts33_CDDE5BE156468A2E8CC9B6A7E34B1006LL5QueryfMa.swift"
error: the replacement path doesn't exist: "/var/folders/dn/x3x4wwkd335_rl91by3tqx5w0000gn/T/swift-generated-sources/@_swiftmacro_10FeatureKit15JobCreationViewV12userContexts33_CDDE5BE156468A2E8CC9B6A7E34B1006LL5QueryfMa.swift"
Topic:
App & System Services
SubTopic:
iCloud & Data
I have not had any successful Schema Migration with CloudKit so far so I'm trying to do with with just very basic attributes, with multiple Versioned Schemas
This is the code in my App Main
var sharedModelContainer: ModelContainer = {
let schema = Schema(versionedSchema: AppSchemaV4.self)
do {
return try ModelContainer(
for: schema,
migrationPlan: AppMigrationPlan.self,
configurations: ModelConfiguration(cloudKitDatabase: .automatic))
} catch {
fatalError("Could not create ModelContainer: \(error)")
}
}()
var body: some Scene {
WindowGroup {
ItemListView()
}
.modelContainer(sharedModelContainer)
}
And this is the code for my MigrationPlan and VersionedSchemas.
typealias Item = AppSchemaV4.Item3
enum AppMigrationPlan: SchemaMigrationPlan {
static var schemas: [any VersionedSchema.Type] {
[AppSchemaV1.self, AppSchemaV2.self, AppSchemaV3.self, AppSchemaV4.self]
}
static var stages: [MigrationStage] {
[migrateV1toV2, migrateV2toV3, migrateV3toV4]
}
static let migrateV1toV2 = MigrationStage.lightweight(
fromVersion: AppSchemaV1.self,
toVersion: AppSchemaV2.self
)
static let migrateV2toV3 = MigrationStage.lightweight(
fromVersion: AppSchemaV2.self,
toVersion: AppSchemaV3.self
)
static let migrateV3toV4 = MigrationStage.custom(
fromVersion: AppSchemaV3.self,
toVersion: AppSchemaV4.self,
willMigrate: nil,
didMigrate: { context in
// Fetch all Item1 instances
let item1Descriptor = FetchDescriptor<AppSchemaV3.Item1>()
let items1 = try context.fetch(item1Descriptor)
// Fetch all Item2 instances
let item2Descriptor = FetchDescriptor<AppSchemaV3.Item2>()
let items2 = try context.fetch(item2Descriptor)
// Convert Item1 to Item3
for item in items1 {
let newItem = AppSchemaV4.Item3(name: item.name, text: "Migrated from Item1 on \(item.date)")
context.insert(newItem)
}
// Convert Item2 to Item3
for item in items2 {
let newItem = AppSchemaV4.Item3(name: item.name, text: "Migrated from Item2 with value \(item.value)")
context.insert(newItem)
}
try? context.save()
}
)
}
enum AppSchemaV1: VersionedSchema {
static var versionIdentifier: Schema.Version = Schema.Version(1, 0, 0)
static var models: [any PersistentModel.Type] {
[Item1.self]
}
@Model class Item1 {
var name: String = ""
init(name: String) {
self.name = name
}
}
}
enum AppSchemaV2: VersionedSchema {
static var versionIdentifier: Schema.Version = Schema.Version(2, 0, 0)
static var models: [any PersistentModel.Type] {
[Item1.self]
}
@Model class Item1 {
var name: String = ""
var date: Date = Date()
init(name: String) {
self.name = name
self.date = Date()
}
}
}
enum AppSchemaV3: VersionedSchema {
static var versionIdentifier: Schema.Version = Schema.Version(3, 0, 0)
static var models: [any PersistentModel.Type] {
[Item1.self, Item2.self]
}
@Model class Item1 {
var name: String = ""
var date: Date = Date()
init(name: String) {
self.name = name
self.date = Date()
}
}
@Model class Item2 {
var name: String = ""
var value: Int = 0
init(name: String, value: Int) {
self.name = name
self.value = value
}
}
}
enum AppSchemaV4: VersionedSchema {
static var versionIdentifier: Schema.Version = Schema.Version(4, 0, 0)
static var models: [any PersistentModel.Type] {
[Item1.self, Item2.self, Item3.self]
}
@Model class Item1 {
var name: String = ""
var date: Date = Date()
init(name: String) {
self.name = name
self.date = Date()
}
}
@Model class Item2 {
var name: String = ""
var value: Int = 0
init(name: String, value: Int) {
self.name = name
self.value = value
}
}
@Model class Item3 {
var name: String = ""
var text: String = ""
init(name: String, text: String) {
self.name = name
self.text = text
}
}
}
My experiment was:
To create Items for every version of the schema
Updating the typealias along the way to reflect the latest Item version.
Updating the Schema in my ModelContainer to reflect the latest Schema Version.
By AppSchemaV4, I have expected all my Items to be displayed/migrated to Item3, but it does not seem to be the case.
I can only see newly created Item3 records.
My question is, is there something wrong with how I'm doing the migrations? or are migrations not really working with CloudKit right now?
Hi everyone,
We’re currently using CKSyncEngine to sync all our locally persisted data across user devices (iOS and macOS) via iCloud.
We’ve noticed something strange and reproducible:
On iOS, when the CKSyncEngine is initialized with manual sync behavior, both manual calls to fetchChanges() and sendChanges() happen nearly instantly (usually within seconds). Automatic syncing is also very fast.
On macOS, when the CKSyncEngine is initialized with manual sync behavior, fetchChanges() and sendChanges() are also fast and responsive.
However, once CKSyncEngine is initialized with automatic syncing enabled on macOS:
sendChanges() still appears to transmit changes immediately.
But automatic fetching becomes significantly slower — often taking minutes to pick up changes from the cloud, even when new data is already available.
Even manual calls to fetchChanges() behave as if they’re throttled or delayed, rather than performing an immediate fetch.
Our questions:
Is this delay in automatic (and post-automatic manual) fetch behavior on macOS expected, or possibly a bug?
Are there specific macOS constraints that impact CKSyncEngine differently than on iOS?
Once CKSyncEngine has been initialized in automatic mode, is fetchChanges() no longer treated as a truly manual trigger?
Is there a recommended workaround to enable fast sync behavior on macOS — for example, by sticking to manual sync configuration and triggering sync using a CKSubscription-based mechanism when remote changes occur?
Any guidance, clarification, or experiences from other developers (or Apple engineers) would be greatly appreciated — especially regarding maintaining parity between iOS and macOS sync performance.
Thanks in advance!
I am having problems when I first loads the app. The time it takes for the Items to be sync from my CloudKit to my local CoreData is too long.
Code
I have the model below defined by my CoreData.
public extension Item {
@nonobjc class func fetchRequest() -> NSFetchRequest<Item> {
NSFetchRequest<Item>(entityName: "Item")
}
@NSManaged var createdAt: Date?
@NSManaged var id: UUID?
@NSManaged var image: Data?
@NSManaged var usdz: Data?
@NSManaged var characteristics: NSSet?
@NSManaged var parent: SomeParent?
}
image and usdz columns are both marked as BinaryData and Attribute Allows External Storage is also selected.
I made a Few tests loading the data when the app is downloaded for the first time. I am loading on my view using the below code:
@FetchRequest(
sortDescriptors: [NSSortDescriptor(keyPath: \Item.createdAt, ascending: true)]
)
private var items: FetchedResults<Item>
var body: some View {
VStack {
ScrollView(.vertical, showsIndicators: false) {
LazyVGrid(columns: columns, spacing: 40) {
ForEach(items, id: \.self) { item in
Text(item.id)
}
}
}
}
}
Test 1 - Just loads everything
When I have on my cloudKit images and usdz a total of 100mb data, it takes around 140 seconds to show some data on my view (Not all items were sync, that takes much longer time)
Test 2 - Trying getting only 10 items at the time ()
This takes the same amount of times the long one . I have added the following in my class, and removed the @FetchRequest:
@State private var items: [Item] = [] // CK
@State private var isLoading = false
@MainActor
func loadMoreData() {
guard !isLoading else { return }
isLoading = true
let fetchRequest = NSFetchRequest<Item>(entityName: "Item")
fetchRequest.predicate = NSPredicate(format: "title != nil AND title != ''")
fetchRequest.fetchLimit = 10
fetchRequest.fetchOffset = items.count
fetchRequest.predicate = getPredicate()
fetchRequest.sortDescriptors = [NSSortDescriptor(keyPath: \Item.createdAt, ascending: true)]
do {
let newItems = try viewContext.fetch(fetchRequest)
DispatchQueue.main.async {
items.append(contentsOf: newItems)
isLoading = false
}
} catch {}
}
Test 2 - Remove all images and usdz from CloudKit set all as Null
Setting all items BinaryData to null, it takes around 8 seconds to Show the list.
So as we can see here, all the solutions that I found are bad. I just wanna go to my CloudKit and fetch the data with my CoreData. And if possible to NOT fetch all the data because that would be not possible (imagine the future with 10 or 20GB or data) What is the solution for this loading problem? What do I need to do/fix in order to load lets say 10 items first, then later on the other items and let the user have a seamlessly experience?
Questions
What are the solutions I have when the user first loads the app?
How to force CoreData to query directly cloudKit?
Does CoreData + CloudKit + NSPersistentCloudKitContainer will download the whole CloudKit database in my local, is that good????
Storing images as BinaryData with Allow external Storage does not seems to be working well, because it is downloading the image even without the need for the image right now, how should I store the Binary data or Images in this case?
I have a Package.swift file that builds and runs from Xcode 15.2 without issue but fails to compile when built from the command line ("swift build"). The swift version is 6.0.3. I'm at wits end trying to diagnose this and would welcome any thoughts.
The error in question is
error: external macro implementation type 'SwiftDataMacros.PersistentModelMacro' could not be found for macro 'Model()'; plugin for module 'SwiftDataMacros' not found
The code associated with the module is very vanilla.
import Foundation
import SwiftData
@Model
public final class MyObject {
@Attribute(.unique) public var id:Int64
public var vertexID:Int64
public var updatedAt:Date
public var codeUSRA:Int32
init(id:Int64, vertexID:Int64, updatedAt:Date, codeUSRA:Int32) {
self.id = id
self.vertexID = vertexID
self.updatedAt = updatedAt
self.codeUSRA = codeUSRA
}
public static func create(id:Int64, vertexID:Int64, updatedAt:Date, codeUSRA:Int32) -> MyObject {
MyObject(id: id, vertexID: vertexID, updatedAt: updatedAt, codeUSRA: codeUSRA)
}
}
Thank you.
The following complex migration consistently crashes the app with the following error:
SwiftData/PersistentModel.swift:726: Fatal error: What kind of backing data is this? SwiftData._KKMDBackingData<SwiftDataMigration.ItemSchemaV1.ItemList>
My app relies on a complex migration that involves these optional 1 to n relationships. Theoretically I could not assign the relationships in the willMigrate block but afterwards I am not able to tell which list and items belonged together.
Steps to reproduce:
Run project
Change typealias CurrentSchema to ItemSchemaV2 instead of ItemSchemaV1.
Run project again -> App crashes
My setup:
Xcode Version 16.2 (16C5032a)
MacOS Sequoia 15.4
iPhone 12 with 18.3.2 (22D82)
Am I doing something wrong or did I stumble upon a bug? I have a demo Xcode project ready but I could not upload it here so I put the code below.
Thanks for your help
typealias CurrentSchema = ItemSchemaV1
typealias ItemList = CurrentSchema.ItemList
typealias Item = CurrentSchema.Item
@main
struct SwiftDataMigrationApp: App {
var sharedModelContainer: ModelContainer = {
do {
return try ModelContainer(for: ItemList.self, migrationPlan: MigrationPlan.self)
} catch {
fatalError("Could not create ModelContainer: \(error)")
}
}()
var body: some Scene {
WindowGroup {
ContentView()
}
.modelContainer(sharedModelContainer)
}
}
This is the migration plan
enum MigrationPlan: SchemaMigrationPlan {
static var schemas: [any VersionedSchema.Type] {
[ItemSchemaV1.self, ItemSchemaV2.self]
}
static var stages: [MigrationStage] = [
MigrationStage.custom(fromVersion: ItemSchemaV1.self, toVersion: ItemSchemaV2.self, willMigrate: { context in
print("Started migration")
let oldlistItems = try context.fetch(FetchDescriptor<ItemSchemaV1.ItemList>())
for list in oldlistItems {
let items = list.items.map { ItemSchemaV2.Item(timestamp: $0.timestamp)}
let newList = ItemSchemaV2.ItemList(items: items, name: list.name, note: "This is a new property")
context.insert(newList)
context.delete(list)
}
try context.save() // Crash indicated here
print("Finished willMigrate")
}, didMigrate: { context in
print("Did migrate successfully")
})
]
}
The versioned schemas
enum ItemSchemaV1: VersionedSchema {
static var versionIdentifier = Schema.Version(1, 0, 0)
static var models: [any PersistentModel.Type] {
[Item.self]
}
@Model
final class Item {
var timestamp: Date
var list: ItemSchemaV1.ItemList?
init(timestamp: Date) {
self.timestamp = timestamp
}
}
@Model
final class ItemList {
@Relationship(deleteRule: .cascade, inverse: \ItemSchemaV1.Item.list)
var items: [Item]
var name: String
init(items: [Item], name: String) {
self.items = items
self.name = name
}
}
}
enum ItemSchemaV2: VersionedSchema {
static var versionIdentifier = Schema.Version(2, 0, 0)
static var models: [any PersistentModel.Type] {
[Item.self]
}
@Model
final class Item {
var timestamp: Date
var list: ItemSchemaV2.ItemList?
init(timestamp: Date) {
self.timestamp = timestamp
}
}
@Model
final class ItemList {
@Relationship(deleteRule: .cascade, inverse: \ItemSchemaV2.Item.list)
var items: [Item]
var name: String
var note: String
init(items: [Item], name: String, note: String = "") {
self.items = items
self.name = name
self.note = note
}
}
}
Last the ContentView:
struct ContentView: View {
@Query private var itemLists: [ItemList]
var body: some View {
NavigationSplitView {
List {
ForEach(itemLists) { list in
NavigationLink {
List(list.items) { item in
Text(item.timestamp.formatted(date: .abbreviated, time: .complete))
}
.navigationTitle(list.name)
} label: {
Text(list.name)
}
}
}
.navigationTitle("Crashing migration demo")
.onAppear {
if itemLists.isEmpty {
for index in 0..<10 {
let items = [Item(timestamp: Date.now)]
let listItem = ItemList(items: items, name: "List No. \(index)")
modelContext.insert(listItem)
}
try! modelContext.save()
}
}
} detail: {
Text("Select an item")
}
}
}
The CloudKit Console includes a Unique Users table in the Usage section.
The numbers here are lower than what I would expect. Does this only track a certain percentage of users, e.g. users have opted in to share analytics with developers?
Hey guys, I'm developing a Swift app, using iCloud to store some data in Containers, and the new Containers I created are iCloud.com.xxx.dev . Therefore, there is a storage called dev in Settings -> icloud -> Manage Account Storage. Currently, the app is still under development and has not been released to the Appstore.
My question: Settings -> icloud -> Manage Account Storage does not display my app name and icon, but only the suffix of the Containers id. Will this change after it is released to the Appstore? Are there any other control methods? Thank you
In Apple Numbers and similar apps, a user can save a document to iCloud Drive, and collaborate with other users. From what I can gather, it seems to use two mechanisms: the document as a whole is synced via iCloud Drive, but when a collaboration is started, it seems to use CloudKit records to do live updates.
I am working on a similar app, that saves documents to iCloud Drive (on Mac, iPad, and iPhone). Currently it only syncs via iCloud Drive, re-reading the entire (often large) document when a remote change occurs. This can lead to a delay of several seconds (up to a minute) for the document to be saved, synced to the server, synced from the server, and re-read.
I'm working on adding a "live sync", i.e. the ability to see changes in as near to real-time as feasible, like in Apple's apps.
The document as a whole will remain syncing via iCloud Drive. My thought is to add a CloudKit CKRecord-based sync when two or more users are collaborating on a document, recording only the diffs for quick updates. The app would no longer re-read the entire document when iCloud Drive updates it while in use, and would instead read the CloudKit records and apply those changes. This should be much faster.
Is my understanding of how Apple does it correct? Does my proposed approach seem sensible? Has anyone else implemented something like this, with iCloud Drive-based documents and a CloudKit live sync?
In terms of technologies, I see that Apple now has a Shared with You framework, with the ability to use a NSItemProvider to start the collaboration. Which raises the question, should I use the iCloud Drive document for the collaboration (as I do now), or the CloudKit CKShare diff? I think I'd have to use the document as a whole, both so it works with the Send Copy option, and so a user that doesn't have the document gets it when using Collaborate. Once the collaboration is underway, I'd want to start the CloudKit channel. So I guess I'd save the CKShare to the server, get its URL, and save that in the document, so another user can read that URL as part of their initial load of the document from iCloud Drive?
Once two (or more) users have the document via iCloud Drive, and the CKShare via the embedded URL, I should be able to do further live-sync updates via CloudKit. If a user closes the document and re-opens it, they'd get the updates via iCloud Drive, so no need to apply any updates from before the document was opened.
Does all this sound reasonable, or am I overlooking some gotcha? I'd appreciate any advice from people who have experience with this kind of syncing.
Topic:
App & System Services
SubTopic:
iCloud & Data
Tags:
CloudKit
Cloud and Local Storage
iCloud Drive
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!
Topic:
App & System Services
SubTopic:
iCloud & Data
Tags:
CloudKit
Cloud and Local Storage
CloudKit JS
I am developing an app that uses CloudKit sharing. I recently upgraded my iPad to use 23A5336a. After that upgrade, I can no longer accept a share that is sent to me.
I have rebooted the iPad and logged out of the iCloud account and logged back in. Every time I get a share link and tap it, it says:
" The owner stopped sharing or your account (xxx) doesn't have permission to open it"
This same code, running on the iOS26 device can share with device running iOS18.
Is this a known defect? Anything I can do to help resolve this issue?
When I try to use an entity created in a CoreData, it gives me: 'PlayerData' is ambiguous for type lookup in this context
why not working?
Topic:
App & System Services
SubTopic:
iCloud & Data
Setup
I am running a versionedSchema for my SwiftData model and attempting a migration. The new version contains a new attribute, with a type of a new custom enum defined in the @Model class, a default value, and a private(set). Migration was completed with a migrationPlan with nil values for willMigrate and didMigrate.
Example - Previous Version
@Model
class MyNumber {
var num: Int
init() {
// Init Code
}
}
Example - Newest Version
@Model
class MyNumber {
var num: Int
private(set) var rounding: RoundAmount = MyNumber.RoundAmount.thirtyMinute
init() {
// Init Code
}
enum RoundAmount {
case fiveMinute, tenMinute, thirtyMinute
}
}
Issue
Running this code, I get a swiftData error for “SwiftData/ModelCoders.swift:1585: nil value passed for a non-optional keyPath, /MyNumber.rounding”
I assume this means a failure of the swiftData lightweight migration? I have reverted the version, removed private(set) and re-tried the migration with no success.
Using the versionedSchema with migrationPlans, are lightweight migrations possible? Could this be an issue with the use of a custom enum? Other changes in my actual project migrated successfully so I’m lost on why I’m having this issue.