I implemented this to receive updates for specific data types and keep the latest daily information up to date. However, for some reason, it only works for a while before stopping completely. Background Delivery internal func backgroundDeliveryForReadTypes(enable: Bool, types: Set<HKQuantityType>) async { do { if enable { try await statusForAuthorizationRequest(toWrite: [], toRead: types) for type in types { try await healthStore.enableBackgroundDelivery(for: type, frequency: .daily) } } else { for type in types { try await healthStore.disableBackgroundDelivery(for: type) } } } catch { debugPrint("Error enabling background delivery: \(error.localizedDescription)") } } HKQueryAnchor internal var walkingActivityQueryAnchor: HKQueryAnchor? { get { if let anchorData = UserDefaults.standard.data(forKey: "walkingActivityAnchor") { return try? NSKeyedUnarchiver.unarchivedObject(ofClass: HKQueryAnchor.self, from: anchorData) } return nil } set { if let newAnchor = newValue { let anchorData = try? NSKeyedArchiver.archivedData(withRootObject: newAnchor, requiringSecureCoding: true) UserDefaults.standard.set(anchorData, forKey: "walkingActivityAnchor") } else { UserDefaults.standard.removeObject(forKey: "walkingActivityAnchor") } } } HKAnchoredObjectQuery internal func observeWalkingActivityInBackground( _ start: Bool, toRead: Set<HKQuantityType>, completion: @escaping @Sendable (Result<WalkingActivityData?, Error>) -> Void ) { if start { guard (walkingActivityQuery == nil) else { return } let predicate = getPredicate(date: Date()) let queryDescriptors = toRead.map { HKQueryDescriptor(sampleType: $0, predicate: predicate) } let handleSamples: @Sendable (HKAnchoredObjectQuery, [HKSample]?, [HKDeletedObject]?, HKQueryAnchor?, Error?) -> Void = { [weak self] _, samples, _, newAnchor, error in guard let self = self else { return } if let error = error { completion(.failure(error)) return } guard let samples = samples, !samples.isEmpty else { completion(.success(nil)) return } Task { self.walkingActivityQueryAnchor = newAnchor let activity = await self.getWalkingActivity(date: Date()) completion(.success(activity)) } } let query = HKAnchoredObjectQuery( queryDescriptors: queryDescriptors, anchor: walkingActivityQueryAnchor, limit: HKObjectQueryNoLimit, resultsHandler: handleSamples ) query.updateHandler = handleSamples healthStore.execute(query) walkingActivityQuery = query } else { if let query = walkingActivityQuery { healthStore.stop(query) walkingActivityQuery = nil } } } WalkingActivityData private func getWalkingActivity(date: Date) async -> WalkingActivityData { async let averageHeartRate = try await self.getAverageHeartRate(date: date) async let steps = try self.getStepCount(date: date) async let durationMinutes = try self.getTotalDurationInMinutes(date: date) async let distanceMeters = try self.getDistanceWalkingRunning(date: date, unit: .meter()) async let activeCalories = try self.getActiveEnergyBurned(date: date) return await WalkingActivityData( date: date, steps: try? steps, activeCalories: try? activeCalories, distanceMeters: try? distanceMeters, durationMinutes: try? durationMinutes, averageHeartRate: try? averageHeartRate ) } Example of getAverageHeartRate func getAverageHeartRate(date: Date) async throws -> Double? { let type = HKQuantityType(.heartRate) _ = try checkAuthorizationStatus(for: type) guard let heartRate = try await getDescriptor( date: date, type: type, options: .discreteAverage ).result(for: healthStore) .statistics(for: date)? .averageQuantity()?.doubleValue(for: HKUnit.count().unitDivided(by: HKUnit.minute())) else { return nil } return Double(String(format: "%.2f", heartRate)) ?? 0.0 } Descriptor & predicate internal func getPredicate(startDate: Date, endDate: Date) -> NSCompoundPredicate { let predicateForSamples = HKQuery.predicateForSamples(withStart: startDate, end: endDate) let excludeManual = NSPredicate(format: "metadata.%K != YES", HKMetadataKeyWasUserEntered) return NSCompoundPredicate(andPredicateWithSubpredicates: [predicateForSamples, excludeManual]) } internal func getDescriptor(startDate: Date, endDate: Date, type: HKQuantityType, options: HKStatisticsOptions) -> HKStatisticsCollectionQueryDescriptor { let calendar = Calendar(identifier: .gregorian) let anchorDate = calendar.date(bySetting: .hour, value: 0, of: startDate)! var interval = DateComponents() interval.day = 1 return HKStatisticsCollectionQueryDescriptor( predicate: HKSamplePredicate.quantitySample(type: type, predicate: getPredicate(startDate: startDate, endDate: endDate)), options: options, anchorDate: anchorDate, intervalComponents: interval ) } Implementation public func observeWalkingActivityInBackground(_ start: Bool, toRead: Set<HKQuantityType>, memberID: String) { observeWalkingActivityInBackground(start, toRead: toRead) { [weak self] result in guard let self = self else { return } } }

I need to be able to create and store a HeartbeatSeries for a given time-period from an Apple Watch, to then retrieve that data from HealthKit to be processed. I have working code which allows me to begin a workout session, which is being used to determine how long a session has been running for. I also have working code for retrieving HeartbeatSeries data from HealthKit. The issue is that no HeartbeatSeries data is being stored into HealthKit as a result of the workout session running. Whether that session is running for as little as 30 seconds or as long as 20 minutes, nothing is stored. However, when I use the the Apple "Meditation" app (formerly known as "Breathe"), I can query HealthKit afterwards and retrieve a list of individual heartbeat timings during that 2 minute period. Therefore, it IS possible to store a HeartbeatSeries from within an app on the Apple Watch. What I would like to know is, how can I use the pulse sensor built-in to the Apple Watch to be able to record a HeartbeatSeries similar to how the Meditation app does it.

Hi, I’m currently working on an app that utilizes sleep data from HealthKit to provide users with meaningful insights about their sleep. To ensure a smooth user experience, I’d like to understand when sleep data collected by the Apple Watch is saved to the HealthKit store and when it gets synced to the iPhone. Ideally, I want to fetch sleep data right after the user wakes up and opens our app. However, to do this reliably, I need to know the timing of how and when this data becomes available in the iPhone’s HealthKit store. I’ve looked through the official documentation and relevant WWDC sessions but couldn’t find clear information on this topic. If anyone has insights or experience with how and when the Apple Watch syncs HealthKit data—especially sleep records—to the iPhone, I’d greatly appreciate your input. Thanks!

Hi, i'm trying to get the number of step counts a person has taken. I decided to pull the data from health kit and the number of steps are incorrect. Come to find out apple health recommends an app called pedometer++ for the number of steps counted and after testing I realized that they are getting the correct number of steps a person is taking. How can I pull the correct number of steps a person has taken? I want to be able to merge the data from watch and phone to make sure we are getting the correct number of steps but not double counting the steps either. any guidance on this would be appreciated! Here's the code snippet that i'm using right now: permissions: { read: [AppleHealthKit.Constants.Permissions.StepCount], write: [], }, }; AppleHealthKit.initHealthKit(permissions, error => { if (error) { console.log('Error initializing HealthKit: ', error); return; } else { dispatch(setAllowHealthKit(true)); getHealthKitData(); console.log('HealthKit initialized successfully'); } }); const getHealthKitData = async () => { try { const today = new Date(); const options = { startDate: new Date(today.setHours(0, 0, 0, 0)).toISOString(), endDate: new Date().toISOString(), }; const steps = await new Promise((resolve, reject) => { AppleHealthKit.getStepCount(options, (error, results) => { if (error) reject(error); resolve(results?.value); }); }); setStepsCount(steps); } catch (error) { console.error('Error fetching HealthKit data:', error); } };

When I set the distanceFilter = 5 (5 meters) in the GPS CLLocationManager I can't display the workout routes in the Apple Fitness app after writing the recorded GPS data to HealthKit via HKWorkoutRouteBuilder. The smaller distanceFilter, Fitness will displays the route. Should I consider setting up a small distanceFilter when developing a workout app on watchOS?

I was wondering which is the preferred way to send a lot of data from sensors of the apple watch to server. It is preferred to send small chucks to iphone and then to server or directly send bulk data to server from watch. How does it affect battery and resources from watch ? Are there any triggers that I can use to ensure best data stream. I need to send at least once a day. Can I do it in background or do I need the user to have my app in the foreground ? Thank you in advance

Has anyone seen the workout buddy options on watch OS yet? I am not able to get it on my watch. My setup is an iPhone 16 and Watch Ultra 1 with the 26 OS I am currently using beta 3. English US language on both and US as region. I am located in Germany though. I restarted both devices multiple times without any changes. Hopefully someone can help.

Are there any HealthKit related changes to be aware of in the new update that enables SPO2 / Blood Oxygen Saturation measurements on certain Apple Watch models within the US? I’m aware of processing happening on the phone…. But beyond that: Does this mean values are then saved to Apple Health? Do these models still take background SPO2 measurements in the same way as other models do? Are these values then visible in third party iOS apps as normal through HealthKit? Do these values sync back to the paired Apple Watch HealthKit store for third party apps to access on the Watch? For reference I have an iOS and WatchOS app that, amongst other features, provides the ability to see your SPO2 values in the Watch app, complications and in the iOS app.

According to the WWDC25 Presentation Track workouts with HealthKit on iOS and iPadOS, there is supposed to be a new property for restoring an active workout after a crash on iOS/iPadOS. The developer documentation also supports this. However, this property does not seem to exist in the latest Xcode 26 beta, even in projects targeting iOS 26.0 as the minimum version. Am I missing something? Has this property not been made available yet? It is actually looking like all of the new iOS 26.0 properties are missing UIScene.ConnectionOptions on my system.

Hello, everyone! I'm seeking some guidance on the App Store review process and technical best practices for a watchOS app. My goal is to create an app that uses HealthKit to continuously monitor a user's heart rate in the background for sessions lasting between 30 minutes and 3 hours. This app would not be a fitness or workout tracker. My primary question is about the best way to achieve this reliably while staying within the App Store Review Guidelines. Is it advisable to use the WorkoutKit framework to start a custom, non-fitness "session" for the purpose of continuous background monitoring? Are there any other recommended APIs or frameworks for this kind of background data collection on watchOS that I should be aware of? What are the key review considerations I should be mindful of, particularly regarding Guideline 4.1 (Design) and the intended use of APIs? My app's core functionality would require this kind of data for a beneficial purpose. I want to ensure my approach is technically sound and has the best chance of a successful review. Any insights or advice from developers who have experience with similar use cases would be incredibly helpful! Thank you!

I've ran into an error with the insertRouteData function of the HKWorkoutRouteBuilder that I can't seem to find any information on. The error is "Unable to find location series 1A193D3B-AFF5-41D8-A967-B1BE08D9F543 during data insert.". It seems to only happen when trying to insert very long routes, in the most recent case it was a 5 hour bike ride with 5900 samples. I save all the route data in a sqlite table as backup and after checking out the data there isn't any red flags as to why it would not insert correctly. Has anyone seen this before and could offer some insight or point me in the right direction to find the source of the error?

Hi! I am using the HKAnchoredObjectQuery to first get a snapshot of the initial results, and then trigger an updateHandler. I need to handle the initial results and the updates separately, which is why I implemented two completions. When I test the code, it works for a while. New and deleted samples trigger the updateHandler. However, after a while there appears an error: [connection] nw_read_request_report [C2] Receive failed with error "Software caused connection abort" Followingly, the updateHandler will stop getting triggered when I add updates in Apple health. Anyone have experience with this? func getMostRecentSample(for sampleType: HKSampleType, anchorKey: String, completion: @escaping (HKQuantitySample?, Error?) -> Swift.Void, updateHandler: @escaping (HKQuantitySample, Error?) -> Swift.Void) {     // If it is the first initialization, anchor is passed as nil     var anchor: HKQueryAnchor? = nil // Check for previous saved anchor in userdefaults     if UserDefaults.standard.object(forKey: anchorKey) != nil {       let data = UserDefaults.standard.object(forKey: anchorKey) as! Data       do {         guard let newAnchor = try NSKeyedUnarchiver.unarchivedObject(ofClass: HKQueryAnchor.self, from: data) else {           print("Could not parse anchor to HKQueryAnchor type")           return         }         anchor = newAnchor       } catch {         print("Error retreiving anchor from UserDefaults")       }     }     let query = HKAnchoredObjectQuery(type: sampleType,                      predicate: nil,                      anchor: anchor,                      limit: HKObjectQueryNoLimit                       ) { (query, samplesOrNil, _, newAnchor, errorOrNil) in       guard let samples = samplesOrNil as? [HKQuantitySample] else {         fatalError("*** An error occurred during the initial query: \(errorOrNil!.localizedDescription) ***")       }       if let anchor = newAnchor {         do {           let data = try NSKeyedArchiver.archivedData(withRootObject: anchor as Any, requiringSecureCoding: false)           UserDefaults.standard.set(data, forKey: anchorKey)         } catch {           print("Error retreiving anchor from UserDefaults")         }       }       completion(samples.last, nil)     }           // Setting up long-running query     query.updateHandler = { (query, samplesOrNil, _, newAnchor, errorOrNil) in       guard let samples = samplesOrNil as? [HKQuantitySample] else {         fatalError("*** An error occurred during an update: \(errorOrNil!.localizedDescription) ***")       }       if let anchor = newAnchor {         do {           let data = try NSKeyedArchiver.archivedData(withRootObject: anchor as Any, requiringSecureCoding: false)           UserDefaults.standard.set(data, forKey: anchorKey)         } catch {           print("Error retreiving anchor from UserDefaults")         }       }       if let sample = samples.last {         updateHandler(sample, nil)       }     }     self.healthStore.execute(query)   }

We are seeing an issue where sending data using the asynchronous method HKWorkoutSession.sendToRemoteWorkoutSession(data: Data) will never return in some cases (no success nor failure). This issue is happening for roughly 5% of Workouts started and will stay broken for the whole workout. The other 95% of the workouts, the connection works flawlessly. This happens on both watchOS 10 and 11, and with phones running iOS 17 or 18. The issue is quite random and not reproducible. Our app has thousands of workouts a day that use the workout session workout data send, with constant messages being send every few seconds. In some of those 5% cases the "sendToRemoteWorkoutSession" will throw way later, like 30+ minutes later, if the watch app is awake long enough to capture a log of a failure. Our code uses the same flow as in the sample project: https://developer.apple.com/documentation/healthkit/workouts_and_activity_rings/building_a_multidevice_workout_app Here is some sample code, which is pretty simple. Setup code: let workoutSession = try HKWorkoutSession(healthStore: healthStore, configuration: configuration) workoutSession.delegate = self activeWorkoutSession?.startMirroringToCompanionDevice { success, error in print("Mirroring started on companion device: \(success), error: \(error)") } workoutSession?.prepare() then later we send data using the workout session: do { print("Will send data") try await workoutSession.sendToRemoteWorkoutSession(data: data) print("Successfully sent data") // This nor the error may be called after waiting extensive amounts of time } catch { print("Failed to send data, error: \(error)") // This nor the success may be called after waiting extensive amounts of time } So far, the only fix is to restart the phone and watch at the same time, which is not a great user experience. Is anyone else seeing this issue? or know how to fix this issue?

For a given date, there are discrepancies between the step counts obtained from HealthKit and those displayed in the Health app. Is it possible for such discrepancies to occur even if step counts are not manually entered and multiple devices are not being used?

Hi everyone! I'm trying to get the total sleep time for a given day, but users report that there's a difference between what my app reports and what the Apple Health app reports. In particular, we're off by 2 minutes less on average. What we're doing is: Get all the samples that are either core, deep, rem or unspecified Cut-off time at 3 PM previous day Merge overlapping intervals Add all the remaining intervals For debugging purposes I'm storing and sending all the raw samples to a server, and I have run tests and I don't find anything wrong. It looks like the number we come up with is correct according to our own rules. I wonder, how is Apple adding up all the samples to arrive at a number that's slightly off to our number. Any insight would be appreciated. Thanks.

I am developing a React Native app for a health monitoring device that connects via Bluetooth and streams live data on iOS. To ensure the uniqueness of the device, I initially planned to use the MAC address. However, I discovered that iOS does not provide access to the original MAC address due to privacy restrictions. Is there an alternative approach to uniquely identifying a Bluetooth device in iOS? I need a reliable way to distinguish devices while maintaining secure and stable connections. Any insights or best practices on handling this in iOS would be greatly appreciated. Looking forward to hearing your suggestions! If anyone has experience with handling Bluetooth device uniqueness on iOS, please share your insights. Thank you!

The WatchOS developer is not allowed to obtain healthKit permission status. The result is always unauthorized (either by clicking the dot/cross in the upper left corner or by turning on all Health, on some, off all). WatchOS 开发获取 healthKit 的权限状态authorizationStatus不准。结果始终都是未授权（无论是点击左上角的点叉号还是开启全部健康项开关，开启部分，关闭所有），怎么处理？

Hello, I’m developing an iOS app that works with sleep data from Apple Watch via HealthKit. I would like to clarify the following: How can an iPhone app detect when a sleep session ends on the Apple Watch? When is sleep data typically written to the HealthKit store on iPhone after sleep ends? Is it immediately after wake-up, or does it depend on certain conditions (e.g., watch charging, connectivity)? Understanding the timing and mechanism of sleep data synchronization is crucial for our app to process accurate and timely health information. Thank you for your assistance.

My research group is using watch sensors (accelerometers, gyroscopes) to track wrist motion to detect and measure eating. https://cecas.clemson.edu/ahoover/bite-counter/ We are running an HKWorkoutSession on the watch so that the app can run for an extended period of time (up to 12 hr) and continue to sense and process motion data. Our app is adding to the activity rings, making it look like the user is exercising the entire time our app is running. Is there a method to prevent our app from contributing to the activity ring measures?

Based on Cooordinate with the companion app in this article by Apple https://developer.apple.com/documentation/healthkit/running-workout-sessions if a workout were to be started on the iPhone companion app but with no Watch available, given HKLiveWorkoutBuilder not available in iOS, does the iPhone app need to implement it's own workout tracking such as a timer for counting the elapsed time and location updates for distance and GPS tracking? If so in an instance where a paired Apple Watch were to exist and the workout is continued in the Watch app should the iPhone companion app stop this custom workout tracking and revert to the mirrored workout from the Watch to ensure accurate and synchronised data between the apps?