I would like to inquire about the feasibility of developing an iOS application with the following requirements:
The app must support real-time audio communication based on UDP.
It needs to maintain a TCP signaling connection, even when the device is locked.
The app will run only on selected devices within a controlled (closed) environment, such as company-managed iPads or iPhones.
Could you please clarify the following:
Is it technically possible to maintain an active TCP connection when the device is locked?
What are the current iOS restrictions or limitations for background execution, particularly related to networking and audio?
Are there any recommended APIs or frameworks (such as VoIP, PushKit, or Background Modes) suitable for this type of application?
Background Tasks
RSS for tagRequest the system to launch your app in the background to run tasks using Background Tasks.
Posts under Background Tasks tag
157 Posts
Selecting any option will automatically load the page
Post
Replies
Boosts
Views
Activity
Hello forum,
I want to keep my app running in the background after user swaps up, for the purpose of workout tracking.
start up the task and continuously receipt GPS updates
process the location data
show the data on a live activity
Two examples
Strava
paddlelogger
Question:
Does this mean, these two apps would just pause when the .backgroundTimeRemaining becomes 0?
How does a workout app "work" in background mode, do I need to handle budget running out?
Topic:
App & System Services
SubTopic:
Widgets & Live Activities
Tags:
Core Location
Maps and Location
Background Tasks
We've seen a recent increase in background terminations:
blue - System Pressure
orange - Task Timeout
I'm trying to understand the increase in system-pressure terminations, since there's no corresponding increase in memory at suspension. Are there other system resources for which iOS will terminate an app?
Topic:
App & System Services
SubTopic:
Processes & Concurrency
Tags:
Organizer Window
Background Tasks
I am building banking application which has audio/video and text chat.
It is intended for contacting bank support.
When user device has auto lock on after 30 seconds, session is ended, and user needs to initiate it again.
Will Apple allow this kind of application to have Audio, Airplay, and Picture in Picture or Voice over IP for background modes for this kind of application or it is against Apple rules (per 2.5.4 - https://developer.apple.com/app-store/review/guidelines/)?
Chat framework uses Web sockets and SIP.
After logging in to the main App, turn on screen recording, then switch to the interface of another App to perform operations. After about ten-odd minutes, when returning to the main App, it was found that the app was forcefully quit by the system, and subsequent operations could not be carried out.
I am work an app development on an app which request an audio function in background as an alert sound.
during debug testing , the function work fine,
but once I testing standalone without debugging , The function not work , it will play out the sound when I back to app.
does any way to trace the issues ?
Hi all,
I’m encountering a consistent issue with SwiftData on watchOS when using CloudKit sync. After enabling:
let config = ModelConfiguration(schema: schema, cloudKitDatabase: .automatic)
…the app terminates ~30–60 seconds into a WKExtendedRuntimeSession. This happens specifically when:
Always-On Display is OFF
The iPhone is disconnected or in Airplane Mode
The app is running in a WKExtendedRuntimeSession (e.g., used for meditation tracking)
The Xcode logs show a warning:
Background Task ("CoreData: CloudKit Setup"), was created over 30 seconds ago. In applications running in the background, this creates a risk of termination.
It appears CloudKit sync setup is being triggered automatically and flagged by the system as an unmanaged long-running task, leading to termination.
Workaround:
Switching to:
let config = ModelConfiguration(schema: schema, cloudKitDatabase: .none)
…prevents the issue entirely — no background task warning, no crash.
Feedback ID submitted: FB17685611
Just wanted to check if others have seen this behavior or found alternative solutions. It seems like something Apple may need to address in SwiftData’s CloudKit handling on watchOS.
Topic:
App & System Services
SubTopic:
iCloud & Data
Tags:
CloudKit
watchOS
Background Tasks
SwiftData
Hi all,
I'm working on a non-interactive macOS application (a service or daemon), and I'm trying to understand the best practices around logging and error reporting, particularly in failure scenarios.
If a daemon or service fails in macOS, where is it expected to log errors, and how can users or developers discover what went wrong?
Specifically, I have a few questions:
What is the recommended location or system for logging errors from a non-interactive macOS application?
Should we use os_log, standard error output, or write directly to files somewhere?
How can a user or developer access these logs to diagnose issues—should logs be visible via the Console app?
Is there a standard approach to making failure information easily accessible for debugging and support, especially for daemons running under launchd?
Any guidance or best practices would be appreciated.
Hi,
I’m trying to download a remote file in the background, but I keep getting a strange behaviour where URLSession download my file indefinitely during a few minutes, without calling urlSession(_:downloadTask:didFinishDownloadingTo:) until the download eventually times out.
To find out that it’s looping, I’ve observed the total bytes written on disk by implementing urlSession(_:downloadTask:didWriteData:totalBytesWritten:totalBytesExpectedToWrite:).
Note that I can't know the size of the file. The server is not able to calculate the size.
Below is my implementation.
I create an instance of URLSession like this:
private lazy var session: URLSession = {
let configuration = URLSessionConfiguration.background(withIdentifier: backgroundIdentifier)
configuration.isDiscretionary = false
configuration.sessionSendsLaunchEvents = true
return URLSession(configuration: configuration,
delegate: self,
delegateQueue: nil)
}()
My service is using async/await so I have implemented an AsyncThrowingStream :
private var downloadTask: URLSessionDownloadTask?
private var continuation: AsyncThrowingStream<(URL, URLResponse), Error>.Continuation?
private var stream: AsyncThrowingStream<(URL, URLResponse), Error> {
AsyncThrowingStream<(URL, URLResponse), Error> { continuation in
self.continuation = continuation
self.continuation?.onTermination = { @Sendable [weak self] data in
self?.downloadTask?.cancel()
}
downloadTask?.resume()
}
}
Then to start the download, I do :
private func download(with request: URLRequest) async throws -> (URL, URLResponse) {
do {
downloadTask = session.downloadTask(with: request)
for try await (url, response) in stream {
return (url, response)
}
throw NetworkingError.couldNotBuildRequest
} catch {
throw error
}
}
Then in the delegate :
public func urlSession(_ session: URLSession,
downloadTask: URLSessionDownloadTask,
didFinishDownloadingTo location: URL) {
guard let response = downloadTask.response,
downloadTask.error == nil,
(response as? HTTPURLResponse)?.statusCode == 200 else {
continuation?.finish(throwing: downloadTask.error)
return
}
do {
let documentsURL = try FileManager.default.url(for: .documentDirectory,
in: .userDomainMask,
appropriateFor: nil,
create: false)
let savedURL = documentsURL.appendingPathComponent(location.lastPathComponent)
try FileManager.default.moveItem(at: location, to: savedURL)
continuation?.yield((savedURL, response))
continuation?.finish()
} catch {
continuation?.finish(throwing: error)
}
}
I also tried to replace let configuration = URLSessionConfiguration.background(withIdentifier: backgroundIdentifier) by let configuration = URLSessionConfiguration.default and this time I get a different error at the end of the download:
Task <0457F755-9C52-4CFB-BDB2-F378D0C94912>.<1> failed strict content length check - expected: 0, received: 530692, received (uncompressed): 0
Task <0457F755-9C52-4CFB-BDB2-F378D0C94912>.<1> finished with error [-1005] Error Domain=NSURLErrorDomain Code=-1005 "The network connection was lost." UserInfo={NSLocalizedDescription=The network connection was lost., NSErrorFailingURLStringKey=https:/<host>:8190/proxy?Func=downloadVideoByUrl&SessionId=slufzwrMadvyJad8Lkmi9RUNAeqeq, NSErrorFailingURLKey=https://<host>:8190/proxy?Func=downloadVideoByUrl&SessionId=slufzwrMadvyJad8Lkmi9RUNAeqeq, _NSURLErrorRelatedURLSessionTaskErrorKey=(
"LocalDownloadTask <0457F755-9C52-4CFB-BDB2-F378D0C94912>.<1>"
), _NSURLErrorFailingURLSessionTaskErrorKey=LocalDownloadTask <0457F755-9C52-4CFB-BDB2-F378D0C94912>.<1>, NSUnderlyingError=0x300d9a7c0 {Error Domain=kCFErrorDomainCFNetwork Code=-1005 "(null)" UserInfo={NSErrorPeerAddressKey=<CFData 0x302139db0 [0x1fcb1f598]>{length = 16, capacity = 16, bytes = 0x10021ffe91e227500000000000000000}}}}
The log "failed strict content length check” made me look into the response header, which has the following:
content-length: 0
Content-Type: application/force-download
Transfer-encoding: chunked
Connection: KEEP-ALIVE
Content-Transfer-Encoding: binary
So it should be fine the way I setup my URLSession.
The download works fine in Chrome/Safari/Chrome or Postman.
My code used to work a couple of weeks before, so I expect something has changed on the server side, but I can’t find what, and I don’t get much help from the guys on the server side.
Has anyone an idea of what’s going on?
Topic:
App & System Services
SubTopic:
Networking
Tags:
Network
Background Tasks
CFNetwork
Foundation
Hi everyone,
I recently built an iOS application that fetches the healthkit data with the BGProcessingTask. It is working as expected in the debug with the physical device connected but its not working in Testflight. I printed out the logs but they don't show that the background process's running.
Here is my code snippet.
func registerBackgroundTask() {
BGTaskScheduler.shared.register(forTaskWithIdentifier: taskIdentifier, using: nil) { task in
LogManager.shared.addBackgroundProcessLog("registering the background task...")
print("registering the background task...")
self.handleBackgroundTask(task: task as! BGProcessingTask)
}
}
func scheduleBackgroundHealthKitSync() {
print("scheduling background task...")
LogManager.shared.addBackgroundProcessLog("scheduling background task...")
let request = BGProcessingTaskRequest(identifier: taskIdentifier)
request.earliestBeginDate = Date(timeIntervalSinceNow: 60 * 1)
request.requiresNetworkConnectivity = true
request.requiresExternalPower = false
do {
try BGTaskScheduler.shared.submit(request)
print("BGProcessingTask scheduled")
LogManager.shared.addBackgroundProcessLog("BGProcessingTask scheduled")
} catch {
print("Failed to schedule task: \(error)")
LogManager.shared.addBackgroundProcessLog("Failed to schedule task: \(error)", isError: true)
print(LogManager.shared.backgroundProcessLogs)
}
}
func handleBackgroundTask(task: BGProcessingTask) {
LogManager.shared.addBackgroundProcessLog("handleBackgroundTask triggered")
print("handleBackgroundTask triggered")
let dispatchGroup = DispatchGroup()
dispatchGroup.enter()
// Reschedule the background sync for the next time
scheduleBackgroundHealthKitSync()
var taskCancelled = false
// Handling expiration
task.expirationHandler = {
taskCancelled = true
LogManager.shared.addBackgroundProcessLog("Background task expired", isError: true)
print("Background task expired")
dispatchGroup.leave()
}
let healthKitManager = HealthKitManager.shared
// Start the background sync operation
healthKitManager.fetchAndSendAllTypes() { success in
if success {
LogManager.shared.addBackgroundProcessLog("HealthKit sync completed successfully")
print("HealthKit sync completed successfully")
} else {
LogManager.shared.addBackgroundProcessLog("HealthKit sync failed", isError: true)
print("HealthKit sync failed")
}
dispatchGroup.leave()
}
// Notify when all tasks are completed
dispatchGroup.notify(queue: .main) {
// Check if the task was cancelled using your own flag or state
if taskCancelled {
task.setTaskCompleted(success: false) // Fail the task if it was cancelled
} else {
task.setTaskCompleted(success: true) // Complete successfully if not cancelled
}
LogManager.shared.addBackgroundProcessLog("Background task ended with status: \(taskCancelled == false)")
print("Background task completed with success: \(taskCancelled == false)") // Logs success or failure
}
}
Here are the logs from my device.
scheduling background task...
BGProcessingTask scheduled
Will App be terminated or suspended when updating to incremental version from app store?
Topic:
App & System Services
SubTopic:
Processes & Concurrency
Tags:
App Store
Core Location
Background Tasks
I do have background Modes added to Xcode. How can I fix this?
Automatic signing failed
Xcode failed to provision this target. Please file a bug report at https://feedbackassistant.apple.com and include the Update Signing report from the Report navigator.
Provisioning profile "iOS Team Provisioning Profile: com.designoverhaul.bladerunner" doesn't include the com.apple.developer.background-modes entitlement.
I emailed Dev Support but they said they cant help.
Thank you.
Dear Apple Support Team,
My app, io.cylonix.sase, has a BGAppRefreshTask (io.cylonix.sase.ios.refresh) that is canceled by dasd ~9ms after submission from a Network Extension. Please help identify the cause and suggest a solution.
App Details:
App ID: io.cylonix.sase
iOS Version: 17.1.1 (iPhone Xs Max)
Network Extension: saseWgNetworkExtension with packet-tunnel-provider entitlement
Use Case: VPN app; Network Extension records file receipts in shared group UserDefaults and schedules BGAppRefreshTask to wake the main app.
App Usage: High (frequently used)
System State: Sufficient resources (not low on battery or memory)
Issue:
The task is submitted but canceled immediately with priority 10. It has never run, so rate-limiting is not an issue.
`
debug 22:09:37.952749-0700 dasd Best binding found for evaluator 0x16d541720: <private>
debug 22:09:37.954483-0700 dasd Invoking selector backgroundTaskSchedulerPermittedIdentifiersWithContext:tableID:unitID:unitBytes: on <LSApplicationRecord 0x724844650>
default 22:09:37.955563-0700 dasd CANCELED: bgRefresh-io.cylonix.sase.ios.refresh:ABDAFA at priority 10 <private>!
Topic:
App & System Services
SubTopic:
Processes & Concurrency
Tags:
Background Tasks
Network Extension
Hello Apple Support,
I’m facing an issue with Background Fetch in my React Native project. When I click on Simulate Background Fetch in Xcode, everything works as expected on the iOS Simulator—background tasks run smoothly, and data is fetched without issues. However, on a real device, the app goes to the background but doesn’t execute any of the scheduled background tasks, and it also remains in the background without terminating.
Here’s some additional context:
React Native Project: I’m using React Native to develop this app, and the background tasks involve:
Getting User Location: Fetching the user’s location in the background.
API Calls: Calling an API to fetch necessary information based on the user’s location.
Scheduling Notifications and Alarms: Scheduling notifications and alarms based on the API response data.
Simulator vs. Real Device:
In the iOS Simulator, all these background tasks trigger and function correctly when I simulate Background Fetch.
On the real device, however, none of these tasks are triggered when I try to simulate Background Fetch. The app only moves to the background without performing any tasks or getting terminated.
Device and Configuration Details:
iOS Version: 17
Device Model: Iphone xs, Iphone 11, iphone 7
Background Modes: Background Fetch is enabled in Capabilities, and I’ve set the fetch interval to the minimum for testing.
I’ve verified that all configurations are correctly set, and I’ve tried restarting the device and Xcode, but the issue persists. Is there something specific about Background Fetch that could prevent it from functioning as expected on physical devices? Any guidance on troubleshooting or additional steps would be highly appreciated.
Thank you!
When I search, it's always people trying to do stuff in the background. I want my app to only do stuff when it is active. And this post https://developer.apple.com/forums/thread/685525 seems to have prevented replies from the start. Which means it's just a documentation page and does not belong in the discussion forums at all, because it prevents all discussion.
How can I enable "Extended Runtime Sessions" for a companion watch app? Here https://developer.apple.com/documentation/watchkit/using-extended-runtime-sessions
in targets under 'Signing & Capabilities' I checked "Audio" and Session Type 'Mindfulness',
I created an ExtendedRuntimeManager.swift file. When running a simulation the error message says
"Extended Runtime Session ungültig: Reason=-1, Error=This application does not have appropriate permissions to schedule a session."
How does the app get the 'appropriate permissions'?
Topic:
Developer Tools & Services
SubTopic:
Swift Playground
Tags:
WatchKit
watchOS
Background Tasks
Thank you for always reading my questions. This time, I'd like to ask some specific questions to gain a deeper understanding of iOS CoreBluetooth.
In the previous question, we learned that although iOS can perform BLE scanning in the background, it is not suitable for use as a data logger.
I was also taught that when using it as a data logger, the iOS app should use GATT communication, and that instead of reading data from the device one by one, it is recommended to store large amounts of data on the device and connect at an appropriate time (such as when the iOS app enters the foreground) to retrieve the data all at once.
My requirements are the same as last time.
I want to send data from a device equipped with some kind of sensor via BLE and display it in a graph in the iOS app.
Data should be acquired every few to tens of seconds and reflected immediately in the graph.
Measurements may take up to 24 hours at most.
I would like to avoid making any major changes to the device. Also, it is unclear whether there will be enough memory for the data logger for 24 hours. Therefore, I am first looking for an appropriate communication method for the iOS app.
iOS is smart and convenient, so I think users will check the measurement status every time they use this iOS app.Therefore, I want to be able to check the changes from the start of measurement to the present in a graph as soon as the app is launched.
I would like to measure data from multiple devices (e.g. 5 devices) at the same time.
I have a question based on the above requirements.
When thinking about the best way to avoid making changes to the device, the only way I could come up with, as someone with insufficient iOS technology, is to keep the connection open via GATT communication and continue to obtain data. However, does iOS GATT communication have any limitations in this regard? Will the OS automatically disconnect GATT communication at a certain time? Also, if that happens, is there a way to automatically reconnect and obtain the data?
Is it possible to smoothly obtain data using iOS GATT communication without any particular restrictions even in the background? Are any other permissions required?
Regarding the sixth requirement. Until last time, with BLE scanning, even if there were multiple devices, the iOS app could measure the data for as many devices as it wanted, but this time, how many devices can be read? In the case of GATT communication with iOS CoreBluetooth, can multiple devices maintain a long connection? Or is it basically better to have one device per connection when creating such an app for iOS? I would like to know if there are any restrictions or points to be careful of when using GATT communication with multiple devices.
I'm sorry for broadening my question, but if neither question 1 nor question 2 works, it will put a burden on the design of the device. If data is stored on the device, is it possible to automatically and periodically connect to the device at a set time interval (for example, once an hour, allowing for some margin of error) when the iOS app is in the background, and obtain log data from the device?
If you can think of any other best methods, please feel free to let me know.
Also, I'd be happy if you could reply with any reference materials or URLs.
Please note that our response may be delayed.
Hi. I have a device that is connected to my phone and sends few bytes at different times. The app caches those events and sends them to server as soon as internet is available.
This all works, but when app goes to background or user locks the phone then after few seconds app has no internet access. It still caches the events that are important but unable to send them until app is brought to foreground.
How can app still connect to server?
I saw few posts saying they solved it by using URLSession with a background mode, but in my case it says:
Terminating app due to uncaught exception 'NSGenericException', reason: 'Upload tasks from NSData are not supported in background sessions.'
As I understood URLSession can download or upload files, but the events comming from BLE device are few bytes, so how to send them to server as soon as possible?
Found this stackoverflow question and gave me some hopes https://stackoverflow.com/questions/63016680/sending-network-request-after-bluetooth-update-while-ios-app-is-in-background but no examples at all.
Topic:
App & System Services
SubTopic:
Core OS
Tags:
Background Tasks
Core Bluetooth
Background Assets
I am suspecting that setting GCController.shouldMonitorBackgroundEvents = true does not actually make the game controllers inputs accessible to the app when it is in the background.
About this value the official documentation says:
A Boolean value that indicates whether the app needs to respond to controller events when it isn’t the frontmost app.
Now the behavior is that when the app is in focus the users inputs do get correctly recognized but as soon as the app enters the background no inputs get recognized. The controller does not get reported as disconnecting and still works for example in launchpad.
I am sure that about 2 months ago when I first used this it did work as one would expect. I also have seen that an app which lets users execute certain actions using their controller has stoped working recently, adding to my suspicion of the feature being broken.
Here is a minimum reproducible example:
import SwiftUI
import GameController
@main
struct TestingControllerConnectionApp: App {
@NSApplicationDelegateAdaptor(AppDelegate.self) var appDelegate
var body: some Scene {
WindowGroup {
ContentView()
}
}
}
class AppDelegate: NSObject, NSApplicationDelegate {
var statusItem: NSStatusItem?
var controller: GCController?
func applicationDidFinishLaunching(_ notification: Notification) {
setupMenuBar()
GCController.shouldMonitorBackgroundEvents = true
NotificationCenter.default.addObserver(
self,
selector: #selector(controllerDidConnect),
name: .GCControllerDidConnect,
object: nil
)
NotificationCenter.default.addObserver(
self,
selector: #selector(controllerDidDisconnect),
name: .GCControllerDidDisconnect,
object: nil
)
}
@objc private func setupMenuBar() {
let menu = NSMenu()
menu.addItem(NSMenuItem(title: "Quit", action: #selector(quitApp), keyEquivalent: "q"))
statusItem = NSStatusBar.system.statusItem(withLength: NSStatusItem.variableLength)
statusItem?.button?.image = NSImage(resource: .controllerBar)
statusItem?.menu = menu
}
@objc private func quitApp() {
NSApp.terminate(nil)
}
@objc private func controllerDidConnect(_ notification: Notification) {
if let controller = notification.object as? GCController {
print("Controller connected")
self.controller = controller
if let gamepad = controller.extendedGamepad {
gamepad.buttonA.pressedChangedHandler = { _, _, pressed in
print("Button A pressed: \(pressed)")
}
}
}
}
@objc private func controllerDidDisconnect(_ notification: Notification) {
print("Controller disconnected")
}
}
This is created in a completely fresh Xcode project and NSHumanInterfaceDeviceUsageDescription has been added.
I am using a PS5 Controller and a Mac running MacOS 15.4.1 which has been restarted and only Xcode and the app have been opened.
I have tested this with setting a multitude of different entitlements and capabilities including:
NSHumanInterfaceDeviceUsageDescription
Supports Controller User Interaction
Required background modes -> App communicates with an accessory
com.apple.security.device.bluetooth
com.apple.security.device.hid
com.apple.security.device.usb
I have also set this value at different points in the code with no change of effect.
Does anybody see if there is any fault in my code or my understanding of the effect of the value 'shouldMonitorBackgroundEvents'? Or is this the functionality actually being broken on Apples part?
Hello,
When my mobile app is terminated, say 30 secs later the CarPlay app stops working. I don't get the access token that is saved in the KeyChain. The same happens when my mobile app is in background for more than 20 secs or so.
Please suggest the way forward. Or is this the expected behavior?