Hello,
I'm trying to work on an iPadOS and macOS app that will rely on the document-based system to create some kind of orientation task to follow.
Let say task1.myfile will be a check point regulation from NYC to SF and task2.myfile will be a visit as many key location as you can in SF.
The file represent the specific landmark location and rules of the game.
And once open, I will be able to read KML/GPS file to evaluate their score based with the current task.
But opened GPS files does not have to be stored in the task file itself, it stay alongside.
I wanted to use that scenario to experiment with SwiftData (I'm a long time CoreData user, I even wrote my own WebDAV based persistent store back in the day), and so, mix both on file and in memory persistent store, with distribution based on object class.
With CoreData it would have been possible, but I do not see how to achieve that with SwiftData and DocumentGroup integration.
Any idea how to do that?
iCloud & Data
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Hi, would it be possible that instead of crashing when calling fetchHistory that function simply throws an error instead?
fetchHistory seems to crash when it cannot understand the models if they are not compatible etc… which is understandable, but it makes it really difficult to handle and debug, there's not a lot of details, and honestly I would just rather that it throws an error and let me ignore a history entry that might be useless rather than crashing the entire app.
Thank you!
Hello,
I'm planning to had an onboarding to one of my apps. I am thinking about a way for a user to not see the onboarding again if he installs the app on another device. So for example, the user completes the onboarding on its iPhone, then downloads the app on its iPad and launch it, he doesn't see the onboarding a second time.
I thought about using iCloud NSUbiquitousKeyValueStored to store the onboarding completion state.
But I'm not sure when the data is synced to the other device logged into the same Apple account:
Immediately even if the app is not installed on the other device (independent from the app, only iCloud thing)?
At the same time as the app install on the other device?
After the app is first launched on the other device?
Of course synchronisation will depend on the Internet connection, speed, etc. so the app should handle the case where the data is not here but what would be the best case scenario?
Thank you,
Axel
Topic:
App & System Services
SubTopic:
iCloud & Data
I haven't been able to find a definitive answer to this online. Is NSUbiquitousKeyValueStore end-to-end encrypted with Advanced Data Protection turned on? It’s not specifically called out here https://support.apple.com/en-us/102651.
Topic:
App & System Services
SubTopic:
iCloud & Data
I have an app that I signed and distribute between some internal testflight users. Potentially I want to invite some 'Public' beta testers which don't need to validate (_World have read rights in the public database)
Question: Do I need to have a working public CloudKit , when users are invited through TestFlight, or are they going to test on the development container?
I understand that when I invite beta-tester without authorization (external testers) they cannot access the developer container, so therefore I need to have the production CloudKit container up and running.
I have tried to populate the public production container, but for whatever reason my upload app still goes to the development container. I have archived the app, and tried, but no luck. I let xcode manage my certificates/profiles. but what do I need to change to be able to use my upload file to upload the production container, instead of the development.
I tried:
init() {
container = CKContainer(identifier: "iCloud.com.xxxx.xxxx")
publicDB = container.publicCloudDatabase
I got no error in the console, but data is always populated to the development database, instead the production.
I tried to create a provisioning profile, but for some reason Xcode doesn't like it. Tried to create one a different provisioning profile manual through the developer portal, for the app. but xcode doesn't want to use that, and mentions that the requirement are already in place.
What can I check/do to solve this.
What is the idiomatic way to use a ModelContext in a document based SwiftData app from a background thread?
The relevant DocumentGroup initializers do not give us direct access to a ModelContainer, only to a ModelContext.
Is it safe to take its modelContext.container and pass it around (for creating a ModelContext on it on a background thread) or to construct a ModelActor with it? Is it safe to e.g. put a ModelActor so created into the environment of the root view of the window and execute various async data operations on it in Tasks throughout the app, as long as these are dispatched from within the window whose root view's ModelContext was used for getting the ModelContainer?
I have an app which uses ubiquitous containers and files in them to share data between devices. It's a bit unusual in that it indexes files in directories the user grants access to, which may or may not exist on a second device - those files are identified by SHA-1 hash. So a second device scanning before iCloud data has fully sync'd can create duplicate references which lead to an unpleasant user experience.
To solve this, I store a small binary index in the root of the ubiquitous file container of the shared data, containing all of the known hashes, and as the user proceeds through the onboarding process, a background thread is attempting to "prime" the ubiquitous container by calling FileManager.default.startDownloadingUbiquitousItemAt() for each expected folder and file in a sane order.
This likely creates a situation not anticipated by the iOS/iCloud integration's design, as it means my app has a sort of precognition of files it should not yet know about.
In the common case, it works, but there is a corner case where iCloud sync has just begun, and very, very little metadata is available (the common case, however, in an emulator), in which two issues come up:
I/O may hang indefinitely, trying to read a file as it is arriving. This one I can work around by running the I/O in a thread created with the POSIX pthread_create and using pthread_cancel to kill it after a timeout.
Attempts to call FileManager.default.startDownloadingUbiquitousItemAt() fails with an error Error Domain=NSCocoaErrorDomain Code=257 "The file couldn’t be opened because you don’t have permission to view it.". The permissions aspect of it is nonsense, but I can believe there's no applicable "sort of exists, sort of doesn't" error code to use and someone punted. The problem is that this same error will be thrown on any attempt to access that file for the life of the application - a restart is required to make it usable.
Clearly, the error or the hallucinated permission failure is cached somewhere in the bowels of iOS's FileManager. I was hoping startAccessingSecurityScopedResource() would allow me to bypass such a cache, as it does with URL.resourceValues() returning stale file sizes and last modified times. But it does not.
Is there some way to clear this state without popping up a UI with an Exit button (not exactly the desired iOS user experience)?
Topic:
App & System Services
SubTopic:
iCloud & Data
Tags:
Foundation
Files and Storage
iOS
iCloud Drive
Does the CloudKit participant limit of 100 include the owner?
As of 2025-05-03, when a macOS user enables iCloud Drive synchronization for Desktop & Documents in US region, does iCloud filter xattrs upon upload or later when downloading back to another macOS host? Or is it the case that iCloud has no filtering of third-party xattrs? Where can I find the technical document outlining exactly what iCloud does with xattrs set on macOS host files and folders synchronized with iCloud Drive?
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.
I'm using SwiftData with CloutKit with a very simple app. Data syncs between iOS, iPadOS, and visionOS, but not macOS. From what I can tell, macOS is never getting CK messages unless I'm running the app from Xcode.
I can listen for the CK messages and show a line in a debug overlay. This works perfectly when I run from Xcode. I can see the notifications and see updates in my app. However, if I just launch the app outside of Xcode I will never see any changes or notifications. It is as if the Mac app never even tries to contact CloudKit.
Schema has been deployed in the CloudKit console. The app is based on the multi-platform Xcode template. Again, only the macOS version has this issue. Is there some extra permission or setting I need to set up in order to use CloudKit on macOS?
@State private var publisher = NotificationCenter.default.publisher(for: NSPersistentCloudKitContainer.eventChangedNotification).receive(on: DispatchQueue.main)
.onReceive(publisher) { notification in
// Listen for changes in CK events
if let userInfo = notification.userInfo,
let event = userInfo[NSPersistentCloudKitContainer.eventNotificationUserInfoKey] as? NSPersistentCloudKitContainer.Event {
let message = "CloudKit Sync: \(event.type.rawValue) - \(event.succeeded ? "Success" : "Failed") - \(event.description)"
// Store for UI display
syncNotifications.append(message)
if syncNotifications.count > 10 {
syncNotifications.removeFirst()
}
}
}
.overlay(alignment: .topTrailing) {
if !syncNotifications.isEmpty {
VStack(alignment: .leading) {
ForEach(syncNotifications, id: \.self) { notification in
Text(notification)
.padding(8)
}
}
.frame(width: 800, height: 500)
.cornerRadius(8)
.background(Color.secondary.opacity(0.2))
.padding()
.transition(.move(edge: .top))
}
}
Does anyone have this error and my app can't be searched in the Apple Store
Hello,
SwiftData is not working correctly with Swift Concurrency. And it’s sad after all this time.
I personally found a regression. The attached code works perfectly fine on iOS 17.5 but doesn’t work correctly on iOS 18 or iOS 18.1.
A model can be updated from the background (Task, Task.detached or ModelActor) and refreshes the UI, but as soon as the same item is updated from the View (fetched via a Query), the next background updates are not reflected anymore in the UI, the UI is not refreshed, the updates are not merged into the main.
How to reproduce:
Launch the app
Tap the plus button in the navigation bar to create a new item
Tap on the “Update from Task”, “Update from Detached Task”, “Update from ModelActor” many times
Notice the time is updated
Tap on the “Update from View” (once or many times)
Notice the time is updated
Tap again on “Update from Task”, “Update from Detached Task”, “Update from ModelActor” many times
Notice that the time is not update anymore
Am I doing something wrong? Or is this a bug in iOS 18/18.1?
Many other posts talk about issues where updates from background thread are not merged into the main thread. I don’t know if they all are related but it would be nice to have
1/ bug fixed, meaning that if I update an item from a background, it’s reflected in the UI, and
2/ proper documentation on how to use SwiftData with Swift Concurrency (ModelActor). I don’t know if what I’m doing in my buttons is correct or not.
Thanks,
Axel
import SwiftData
import SwiftUI
@main
struct FB_SwiftData_BackgroundApp: App {
var body: some Scene {
WindowGroup {
ContentView()
.modelContainer(for: Item.self)
}
}
}
struct ContentView: View {
@Environment(\.modelContext) private var modelContext
@State private var simpleModelActor: SimpleModelActor!
@Query private var items: [Item]
var body: some View {
NavigationView {
VStack {
if let firstItem: Item = items.first {
Text(firstItem.timestamp, format: Date.FormatStyle(date: .omitted, time: .standard))
.font(.largeTitle)
.fontWeight(.heavy)
Button("Update from Task") {
let modelContainer: ModelContainer = modelContext.container
let itemID: Item.ID = firstItem.persistentModelID
Task {
let context: ModelContext = ModelContext(modelContainer)
guard let itemInContext: Item = context.model(for: itemID) as? Item else { return }
itemInContext.timestamp = Date.now.addingTimeInterval(.random(in: 0...2000))
try context.save()
}
}
.buttonStyle(.bordered)
Button("Update from Detached Task") {
let container: ModelContainer = modelContext.container
let itemID: Item.ID = firstItem.persistentModelID
Task.detached {
let context: ModelContext = ModelContext(container)
guard let itemInContext: Item = context.model(for: itemID) as? Item else { return }
itemInContext.timestamp = Date.now.addingTimeInterval(.random(in: 0...2000))
try context.save()
}
}
.buttonStyle(.bordered)
Button("Update from ModelActor") {
let container: ModelContainer = modelContext.container
let persistentModelID: Item.ID = firstItem.persistentModelID
Task.detached {
let actor: SimpleModelActor = SimpleModelActor(modelContainer: container)
await actor.updateItem(identifier: persistentModelID)
}
}
.buttonStyle(.bordered)
Button("Update from ModelActor in State") {
let container: ModelContainer = modelContext.container
let persistentModelID: Item.ID = firstItem.persistentModelID
Task.detached {
let actor: SimpleModelActor = SimpleModelActor(modelContainer: container)
await MainActor.run {
simpleModelActor = actor
}
await actor.updateItem(identifier: persistentModelID)
}
}
.buttonStyle(.bordered)
Divider()
.padding(.vertical)
Button("Update from View") {
firstItem.timestamp = Date.now.addingTimeInterval(.random(in: 0...2000))
}
.buttonStyle(.bordered)
} else {
ContentUnavailableView(
"No Data",
systemImage: "slash.circle", //
description: Text("Tap the plus button in the toolbar")
)
}
}
.toolbar {
ToolbarItem(placement: .primaryAction) {
Button(action: addItem) {
Label("Add Item", systemImage: "plus")
}
}
}
}
}
private func addItem() {
modelContext.insert(Item(timestamp: Date.now))
try? modelContext.save()
}
}
@ModelActor
final actor SimpleModelActor {
var context: String = ""
func updateItem(identifier: Item.ID) {
guard let item = self[identifier, as: Item.self] else {
return
}
item.timestamp = Date.now.addingTimeInterval(.random(in: 0...2000))
try! modelContext.save()
}
}
@Model
final class Item: Identifiable {
var timestamp: Date
init(timestamp: Date) {
self.timestamp = timestamp
}
}
I have the following lines of code to access data through CoreData.
import Foundation
import CoreData
import CloudKit
class CoreDataManager {
static let instance = CoreDataManager()
let container: NSPersistentCloudKitContainer
let context: NSManagedObjectContext
init() {
container = NSPersistentCloudKitContainer(name: "ABC")
container.loadPersistentStores(completionHandler: { (storeDescription, error) in
if let error = error as NSError? {
print(error.userInfo)
}
})
context = container.viewContext
context.automaticallyMergesChangesFromParent = true
context.mergePolicy = NSMergePolicy(merge: .mergeByPropertyObjectTrumpMergePolicyType)
}
func save() {
do {
try container.viewContext.save()
print("Saved successfully")
} catch {
print("Error in saving data: \(error.localizedDescription)")
}
}
}
I have confirmed that I can share data between iPhone and iPad. Now, I need to use AppGroup as well. I have changed my code as follows.
import Foundation
import CoreData
import CloudKit
class CoreDataManager {
static let shared = CoreDataManager()
let container: NSPersistentContainer
let context: NSManagedObjectContext
init() {
container = NSPersistentCloudKitContainer(name: "ABC")
container.persistentStoreDescriptions = [NSPersistentStoreDescription(url: FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: "some group name")!.appendingPathComponent("CoreDataMama.sqlite"))]
container.loadPersistentStores(completionHandler: { (description, error) in
if let error = error as NSError? {
print("Unresolved error \(error), \(error.userInfo)")
}
})
context = container.viewContext
context.automaticallyMergesChangesFromParent = true
context.mergePolicy = NSMergePolicy(merge: .mergeByPropertyObjectTrumpMergePolicyType)
}
func save() {
do {
try container.viewContext.save()
print("Saved successfully")
} catch {
print("Error in saving data: \(error.localizedDescription)")
}
}
}
Other files being unaltered, my sample apps aren't sharing data. What am I doing wrong? Just FYI, I'm using actual devices. Thank you for your reading this topic.
"No records found"
If I create a new record on the console, I can copy the record name.
I can then query for recordName and get that individual record back.
BUT no other queries work. I cannot query all records. I cannot query by individual property.
Just returns "no records found"
Seems like my indexes got messed up. Is there a way to reset indexes on prod?
This is on a coredata.cloudkit managed zone.
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.
Topic:
App & System Services
SubTopic:
iCloud & Data
I can't access the CloudKit Console. It started to be unresponsive for hours today.
It looks like sync'ing is still working, but I would like to reset the environment during my development!
Is it possible to control CloudKit Console using the command line?
Hi everyone
In the last 24 hours, I’ve been running into some issues with the CloudKit console.
Most of the time, I‘ll get an error stating an error has caused this web page to stop working correctly. Reloading doesn’t fix the issue, nor does using different browsers:
Today I’ve got another error, something along the lines of the Console not being able to fetch the teams I’m assigned to and an XHF error pop-up.
Has anyone encountered the same issues? After trying multiple times, I’m able to reach my database but it’s a bit frustrating as it’s very unreliable this way.
Thanks for your feedback!
Dave
Hello Devs,
I'm encountering a persistent INTERNAL_ERROR (HTTP 500) when making Server-to-Server API calls to CloudKit, specifically when trying to hit the /users/current endpoint, even after meticulously verifying all client-side components. I'm hoping someone might have insight into what could cause this.
Context:
Goal: Authenticate to CloudKit from a Vercel Serverless Function (Node.js) to perform operations like record queries.
Problem Endpoint: POST https://api.apple-cloudkit.com/database/1/iCloud.com.dannybaseball.Danny-Baseball/production/public/users/current
Key Generation Method: Using the CloudKit Dashboard's "Tokens & Keys" -> "New Server-to-Server Key" flow, where I generate the private key using openssl ecparam -name prime256v1 -genkey -noout -out mykey.pem, then extract the public key using openssl ec -in mykey.pem -pubout, and paste the public key material (between BEGIN/END markers) into the dashboard. The private key was then converted to PKCS#8 format using openssl pkcs8 -topk8 -nocrypt -in mykey.pem -out mykey_pkcs8.pem.
Current Setup Being Tested (in a Vercel Node.js function):
CLOUDKIT_CONTAINER: iCloud.com.dannybaseball.Danny-Baseball
CLOUDKIT_KEY_ID: 9368dddf141ce9bc0da743b9f69bc3eda132b9bb3e62a4167e428d4f320b656e (This is the Key ID generated from the CloudKit Dashboard for the public key I provided).
CLOUDKIT_P8_KEY (Environment Variable): Contains the base64 encoded string of the entire content of my PKCS#8 formatted private key file.
Key Processing in Code:
const p8Base64 = process.env.CLOUDKIT_P8_KEY;
const privateKeyPEM = Buffer.from(p8Base64, 'base64').toString('utf8');
// This privateKeyPEM string starts with "-----BEGIN PRIVATE KEY-----" and ends with "-----END PRIVATE KEY-----"
const privateKey = crypto.createPrivateKey({ key: privateKeyPEM, format: 'pem' });
// This line SUCCEEDS without DECODER errors in my Vercel function logs.
Use code with caution.
JavaScript
Request Body for /users/current: "{}"
Signing String (message = Date:BodyHash:Path):
Date: Correct ISO8601 format (e.g., "2025-05-21T19:38:11.886Z")
BodyHash: Correct SHA256 hash of "{}", then Base64 encoded (e.g., "RBNvo1WzZ4oRRq0W9+hknpT7T8If536DEMBg9hyq/4o=")
Path: Exactly /database/1/iCloud.com.dannybaseball.Danny-Baseball/production/public/users/current
Headers:
X-Apple-CloudKit-Request-KeyID: Set to the correct Key ID.
X-Apple-CloudKit-Request-ISO8601Date: Set to the date used in the signature.
X-Apple-CloudKit-Request-SignatureV1: Set to the generated signature.
X-Apple-CloudKit-Environment: "production"
Content-Type: "application/json"
Observed Behavior & Logs:
The Node.js crypto.createPrivateKey call successfully parses the decoded PEM key in my Vercel function.
The request is sent to CloudKit.
CloudKit responds with HTTP 500 and the following JSON body (UUID varies per request):
{
"uuid": "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
"serverErrorCode": "INTERNAL_ERROR"
}
Use code with caution.
Json
This happens consistently. Previously, with other key pairs or different P8 processing attempts, I was getting AUTHENTICATION_FAILED (401) or local DECODER errors. Now that the key parsing is successful on my end with this current key pair and setup, I'm hitting this INTERNAL_ERROR.
Troubleshooting Done:
Verified Key ID (9368dddf...) is correct and corresponds to the key generated via CloudKit Dashboard.
Verified Container ID (iCloud.com.dannybaseball.Danny-Baseball) is correct.
Successfully parsed the private key from the environment variable (after base64 decoding) within the Vercel function.
Meticulously checked the signing string components (Date, BodyHash, Path) against Apple's documentation. Path format is /database/1////.
Ensured all required headers are present with correct values.
Local Node.js tests (bypassing Vercel but using the same key data and signing logic) also result in this INTERNAL_ERROR.
Question:
What could cause CloudKit to return an INTERNAL_ERROR (500) for a /users/current request when the client-side key parsing is successful and all request components (path, body hash for signature, date, headers) appear to conform exactly to the Server-to-Server Web Services Reference?
Are there any known subtle issues with EC keys generated via openssl ecparam (and then converted to PKCS#8) that might lead to this, even if crypto.createPrivateKey parses them in Node.js?
Could there be an issue with my specific Key ID or container that would manifest this way, requiring Apple intervention?
Any insights or suggestions would be greatly appreciated. I can provide more detailed logs of the request components if needed.
Thank you!
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!