Hi! We are trying to request the SensorKit entitlement (com.apple.developer.sensorkit.reader.allow) for a research app we’re working on. When we go to Apple Developer → Certificates, Identifiers & Profiles → Identifiers, we see the SensorKit capability listed under "Capability Requests", but: There’s no form or button to submit the request, unlike with other capabilities. We tested this using an Account Holder role, and also tried requesting other capabilities — which do show the form correctly, so this seems to be an issue specific to SensorKit. We’d appreciate any guidance on: Whether this is a known issue with the SensorKit request flow. If there’s an alternative way to request this capability while the form is unavailable. Thanks in advance!

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!

We are a research team conducting a study collecting subject's SensorKit speech data, and we've encountered some questions we couldn't resolve ourselves or by looking up the online SensorKit documentation: Microphone Activation: In general, how is the microphone being turned on to capture a speech session? And how was each session determined to be an independent session? Negative Values: In the speech classification data, there are entries where some of the start and end values are negative (see screenshot below). How should we interpret and handle these values? Is it safe to filter them out? Duplicated sessions: From the same screenshot you can see there are multiple session identifiers linked to the same subject with the same timestamp - what does this represent? Another Negative Values: The same question for speech recognition data's average pause duration, what does the -1 mean and should we remove them as well? (Note that these screenshot got rid of subject IDs for privacy purposes but each screenshot was from one subject.) We greatly appreciate your time and help.

Hi everyone, I’m building a sports performance app for Apple Watch that uses the onboard IMU to analyze swings and impacts in sports like tennis and golf. The goal is to estimate club/racket head speed, ball speed, and shot quality in real time from wrist motion data. With Core Motion, I can currently get deviceMotion updates at ~100 Hz. While this is fine for general movement tracking, the actual ball impact happens much faster — 5–10 ms in tennis and ~0.5 ms in golf. Many of the high-frequency vibration/impact components are missed at 100 Hz, making it hard to directly measure or more accurately estimate certain performance metrics. Questions for Apple / community: 1. Is there a way to access raw accelerometer and gyroscope data at higher sampling rates (e.g., 500–1000 Hz) on Apple Watch? 2. If not, is this due to hardware limitations or an API/software constraint? 3. Are there any research, partner, or beta programs that allow deeper sensor access for sports-science use cases? Even modest increases in IMU sampling could unlock more accurate ball-speed estimates, impact force analysis, and strike-quality detection without needing external sensors — making Apple Watch a best-in-class wearable for precision sports analytics. Happy to share more about the current approach, sample data, and potential use cases if helpful. Thanks, Max

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?

I want use SensorKit data for research purposes in my current app. I have applied for and received permission from Apple to access SensorKit Data. I have granting all the necessary permissions. But no data retrieved. I am using didCompleteFetch for retrieving data from Sensorkit. CompleteFetch method calls but find the data. Below is my SensorKitManager Code. import SensorKit import Foundation protocol SensorManagerDelegate: AnyObject { func didFetchPhoneUsageReport(_ reports: [SRPhoneUsageReport]) func didFetchAmbientLightSensorData(_ data: [SRAmbientLightSample]) func didFailFetchingData(error: Error) } class SensorManager: NSObject, SRSensorReaderDelegate { private let phoneUsageReader: SRSensorReader private let ambientLightReader: SRSensorReader weak var delegate: SensorManagerDelegate? override init() { self.phoneUsageReader = SRSensorReader(sensor: .phoneUsageReport) self.ambientLightReader = SRSensorReader(sensor: .ambientLightSensor) super.init() self.phoneUsageReader.delegate = self self.ambientLightReader.delegate = self } func requestAuthorization() { let sensors: Set<SRSensor> = [.phoneUsageReport, .ambientLightSensor] guard phoneUsageReader.authorizationStatus != .authorized || ambientLightReader.authorizationStatus != .authorized else { log("Already authorized. Fetching data directly...") fetchSensorData() return } SRSensorReader.requestAuthorization(sensors: sensors) { [weak self] error in DispatchQueue.main.async { if let error = error { self?.log("Authorization failed: \(error.localizedDescription)", isError: true) self?.delegate?.didFailFetchingData(error: error) } else { self?.log("Authorization granted.") self?.fetchSensorData() } } } } func fetchSensorData() { guard let fromDate = Calendar.current.date(byAdding: .day, value: -1, to: Date()) else { log("Failed to calculate 'from' date.", isError: true) return } let fromTime = SRAbsoluteTime.fromCFAbsoluteTime(_cf: fromDate.timeIntervalSinceReferenceDate) let toTime = SRAbsoluteTime.fromCFAbsoluteTime(_cf: Date().timeIntervalSinceReferenceDate) let phoneUsageRequest = SRFetchRequest() phoneUsageRequest.from = fromTime phoneUsageRequest.to = toTime phoneUsageRequest.device = SRDevice.current let ambientLightRequest = SRFetchRequest() ambientLightRequest.from = fromTime ambientLightRequest.to = toTime ambientLightRequest.device = SRDevice.current phoneUsageReader.fetch(phoneUsageRequest) ambientLightReader.fetch(ambientLightRequest) } // ✅ Delegate Methods func sensorReader(_ reader: SRSensorReader, didCompleteFetch fetchRequest: SRFetchRequest) { Task.detached { if reader.sensor == .phoneUsageReport { if let samples = reader.fetch(fetchRequest) as? [SRPhoneUsageReport] { DispatchQueue.main.async { [weak self] in self?.delegate?.didFetchPhoneUsageReport(samples) } } } else if reader.sensor == .ambientLightSensor { if let samples = reader.fetch(fetchRequest) as? [SRAmbientLightSample] { DispatchQueue.main.async { [weak self] in self?.delegate?.didFetchAmbientLightSensorData(samples) } } } } } func sensorReader(_ reader: SRSensorReader, fetching fetchRequest: SRFetchRequest, didFetchResult result: SRFetchResult<AnyObject>) -> Bool { return true } func sensorReader(_ reader: SRSensorReader, fetching fetchRequest: SRFetchRequest, failedWithError error: any Error) { DispatchQueue.main.async { [weak self] in self?.delegate?.didFailFetchingData(error: error) } } // MARK: - Logging Helper private func log(_ message: String, isError: Bool = false) { if isError { print("❌ [SensorManager] \(message)") } else { print("✅ [SensorManager] \(message)") } } } And ViewController import UIKit import SensorKit class ViewController: UIViewController { private var sensorManager: SensorManager! override func viewDidLoad() { super.viewDidLoad() setupSensorManager() } private func setupSensorManager() { sensorManager = SensorManager() sensorManager.delegate = self sensorManager.requestAuthorization() } } // MARK: - SensorManagerDelegate extension ViewController: SensorManagerDelegate { func didFetchPhoneUsageReport(_ reports: [SRPhoneUsageReport]) { for report in reports { print("Total Calls: (report.totalOutgoingCalls + report.totalIncomingCalls)") print("Outgoing Calls: (report.totalOutgoingCalls)") print("Incoming Calls: (report.totalIncomingCalls)") print("Total Call Duration: (report.totalPhoneCallDuration) seconds") } } func didFetchAmbientLightSensorData(_ data: [SRAmbientLightSample]) { for sample in data { print(sample) } } func didFailFetchingData(error: Error) { print("Failed to fetch data: \(error.localizedDescription)") } } Could anyone please assist me in resolving this issue? Any guidance or troubleshooting steps would be greatly appreciated.

I have received permission from Apple to access SensorKit data for my app. I have granted all necessary permissions, but no data is being retrieved. The didCompleteFetch method is being called, but I’m unsure where to find event data like Device Usage and Ambient Light. Additionally, the didFetchResult method is never called. Could anyone please assist me in resolving this issue? Any guidance or troubleshooting steps would be greatly appreciated. import SensorKit class ViewController: UIViewController, SRSensorReaderDelegate { let store = SRSensorReader(sensor: .deviceUsageReport) override func viewDidLoad() { super.viewDidLoad() requestSensorAuthorization() } func requestSensorAuthorization() { var sensors: Set<SRSensor> = [ .accelerometer, .deviceUsageReport, .messagesUsageReport, .visits, .keyboardMetrics, .phoneUsageReport, .ambientLightSensor ] if #available(iOS 16.4, *) { sensors.insert(.mediaEvents) } SRSensorReader.requestAuthorization(sensors: sensors) { error in if let error = error { print("Authorization failed: \(error.localizedDescription)") } else { self.store.startRecording() self.requestSensorData() print("Authorization granted for requested sensors.") } } } func requestSensorData() { let fromTime = SRAbsoluteTime.fromCFAbsoluteTime(_cf: Date().addingTimeInterval(-60 * 60).timeIntervalSinceReferenceDate) let toTime = SRAbsoluteTime.fromCFAbsoluteTime(_cf: Date().timeIntervalSinceReferenceDate) let request = SRFetchRequest() request.from = fromTime request.to = toTime request.device = SRDevice.current store.fetch(request) store.delegate = self } func sensorReader(_ reader: SRSensorReader, didCompleteFetch fetchRequest: SRFetchRequest) { print("Fetch request completed: \(fetchRequest.from) to \(fetchRequest.to)") Task { do { let samples = try await reader.fetch(fetchRequest) print("Samples count: \(samples)") } catch { print("Error Fetching Data: \(error.localizedDescription)") } } } func sensorReader(_ reader: SRSensorReader, fetching fetchRequest: SRFetchRequest, didFetchResult result: SRFetchResult<AnyObject>) -> Bool { print(result) return true } }

I keep seeing a red action item to complete a task in settings. IOS beta keeps indicating that I need to enable sensor & usage data. Everything is enabled. I literally enabled everything to get it to go away, but it is still there. Suggestions?

As of iOS 18.1 being released we are having issues with our users experiencing issues with our app that relies on strobing the device torch. We have narrowed this down to being caused on devices with adaptive true-tone flash and have submitted a radar: FB15787160. The issue seems to be caused by ambient light levels. If run in a dark room, the torch strobes exactly as effectively as in previous iOS versions, if run in a light room, or outdoors, or near a window, the strobe will run for ~1s and then the torch will get stuck on for half a second or so (less frequently it gets stuck off) and then it will strobe again for ~1s and this behaviour repeats indefinitely. If we go to a darker environment, and background and then foreground the app (this is required) the issue is resolved, until moving to an area with higher ambient light levels again. We have done a lot of debugging, and also discovered that turning off "Auto-Brightness" from Settings -> Accessibility -> Display & Text Size resolves the issue. We have also viewed logs from Console.app at the time of the issue occurring and it seems to be that there are quite sporadic ambient light level readings at the time at which the issue occurs. The light readings transition from ~100 Lux to ~8000 Lux at the point that the issue starts occurring (seemingly caused by the rear sensor being affected by the torch). With "Auto-Brightness" turned off, it seems these readings stay at lower levels. This is rendering the primary use case of our app essentially useless, would be great to get to the bottom of it! We can't even really detect it in-app as I believe using SensorKit is restricted to research applications and requires a review process with Apple before accessing? Edit: It's worth noting this is also affecting other apps with strobe functionality in the exact same way

I want SensorKit data for research purposes in my current application. I have applied for and received permission from Apple to access SensorKit data. During implementation, I encountered an issue in which no data was being retrieved despite granting all the necessary permissions. I am using did CompleteFetch & didFetchResult delegate methods for retrieving data from Sensorkit. CompleteFetch method calls but where I can find different event data like Device usage, Ambient Light, etc? & didFetchResult method does not call. Methods I am using: 1. func sensorReader(_ reader: SRSensorReader, didCompleteFetch fetchRequest: SRFetchRequest) 2. func sensorReader(_ reader: SRSensorReader, fetching fetchRequest: SRFetchRequest, didFetchResult result: SRFetchResult<AnyObject>) -> Bool Could anyone please assist me in resolving this issue? Any guidance or troubleshooting steps would be greatly appreciated.

基于iPhone 14 Max相机，实现模型识别，并在识别对象周围画一个矩形框。宽度和高度使用激光雷达计算，并在实时更新的图像上以厘米为单位显示。 swift code

Hi there. We are trying to implement SensorKit into our App to explore the data quality of accelerometer data recorded even when the App is terminated. So far we managed everything to work, even the fetch, except the SRSensorReaderDelegate never seems to reach func sensorReader(_ reader: SRSensorReader, fetching fetchRequest: SRFetchRequest, didFetchResult result: SRFetchResult) -> Bool { ... } Any clue as to what we need to adjust in our code to get the FetchResult? import Foundation import SensorKit import CoreMotion import os.log class SensorKitDataManager: NSObject, SRSensorReaderDelegate { static let shared = SensorKitDataManager() // Sensor Readers let accelerometerReader = SRSensorReader(sensor: .accelerometer) let rotationRateReader = SRSensorReader(sensor: .rotationRate) let deviceUsageReader = SRSensorReader(sensor: .deviceUsageReport) let phoneUsageReader = SRSensorReader(sensor: .phoneUsageReport) let wristUsageReader = SRSensorReader(sensor: .onWristState) var startTime: CFTimeInterval = CFTimeInterval(Date().timeIntervalSince1970) var endTime: CFTimeInterval = CFTimeInterval(Date().timeIntervalSince1970) override init() { super.init() configureSensorReaders() } // Configure sensor readers and set delegate private func configureSensorReaders() { if SRSensorReader(sensor: .accelerometer).authorizationStatus == .authorized { accelerometerReader.delegate = self } ... } func sensorReaderWillStartRecording(_ reader: SRSensorReader) { print("\(reader.description) Delegate starts recording") } func sensorReader(_ reader: SRSensorReader, startRecordingFailedWithError error: Error) { print("\(reader.description) Delegate failed recording") } func sensorReader(_ reader: SRSensorReader, didChange authorizationStatus: SRAuthorizationStatus) { if reader.sensor == .accelerometer { if authorizationStatus == SRAuthorizationStatus.authorized { accelerometerReader.startRecording() } else if authorizationStatus == SRAuthorizationStatus.denied { accelerometerReader.stopRecording() } } ... } // Request SensorKit Authorization func requestAuthorization() { } if UserDefaults.standard.bool(forKey: "JTrack_accelerometerEnabled") && accelerometerReader.authorizationStatus == .notDetermined { SRSensorReader.requestAuthorization(sensors: [.accelerometer]) { error in if let error = error { os_log("Authorization denied: %@", log: OSLog.default, type: .error, error.localizedDescription) } else { os_log("Authorization granted for accelerometer sensor", log: OSLog.default, type: .info) } } } ... self.startRecordingIfAuthorized() } // Start recording for each authorized sensor private func startRecordingIfAuthorized() { if accelerometerReader.authorizationStatus == .authorized { accelerometerReader.startRecording() } ... } func fetchAllDataSinceJoined(from startTime: CFTimeInterval, to endTime: CFTimeInterval) { self.startTime = startTime self.endTime = endTime if accelerometerReader.authorizationStatus == .authorized { accelerometerReader.fetchDevices() } .... } func stopAllRecordings() { if accelerometerReader.authorizationStatus == .authorized { accelerometerReader.stopRecording() } ... } func sensorReader(_ reader: SRSensorReader, didFetch devices: [SRDevice]) { let now = CFTimeInterval(Date().timeIntervalSince1970) // Ensure the data is at least 24 hours old let holdingPeriod: CFTimeInterval = 24 * 60 * 60 // 24 hours in seconds let earliestFetchTime = now - holdingPeriod // Adjust the start time if it's within the holding period let adjustedStartTime = min(startTime, earliestFetchTime) // If adjustedStartTime is after endTime, no data is available for fetching guard adjustedStartTime < endTime else { print("No data available to fetch as it falls within the 24-hour holding period.") return } let fetchRequest = SRFetchRequest() fetchRequest.from = SRAbsoluteTime(adjustedStartTime) fetchRequest.to = SRAbsoluteTime(endTime) // Log information about the devices that contributed data for device in devices { print("Device model: \(device.model), OS version: \(device.systemVersion), Identifier: \(device.description)") if device.model == "iPhone" { fetchRequest.device = device } } if accelerometerReader.authorizationStatus == .authorized { accelerometerReader.fetch(fetchRequest) } ... } // SensorKit Delegate Methods func sensorReader(_ reader: SRSensorReader, didCompleteFetch fetchRequest: SRFetchRequest) { os_log("Fetch completed for sensor: %@", log: OSLog.default, type: .info, reader.sensor.rawValue) } func sensorReader(_ reader: SRSensorReader, fetching fetchRequest: SRFetchRequest, didFetchResult result: SRFetchResult<AnyObject>) -> Bool { if reader.sensor == .accelerometer { .... } .... } func sensorReaderDidStopRecording(_ reader: SRSensorReader) { print("\(reader.description) Delegate stops recording") } func sensorReader(_ reader: SRSensorReader, stopRecordingFailedWithError error: Error) { print("\(reader.description) Delegate failed stopping") }

I´m working within the health felid with a few apps. Accordingly to science one of the most important parts to keep healthy is every day walking. But it is not to walk slow. You need to come to a little speed (not running or even jogging). But to rais your puls. This is when you get the "real health effect". In general it is around 6km/h. It would be great if apple could make this info available for us developers. I think lots of developers will be happa and use this to make better apps and get more people in a healtheyer life. Looking forward to get some feedback on this. Thank you! Cheers Peter

Hello, I am currently developing an application using SensorKit to retrieve visit data. While the data retrieval works smoothly on one iPhone (iPhone 14, iOS 18.0.1), it fails on other devices, including: iPhone 15 Pro Max with iOS 18.1 Beta Another iPhone 14 with iOS 18.0 I’ve verified that the entitlements are configured properly, and the app has the necessary SensorKit visit permissions across all devices. Despite these steps, only one of the phones is able to retrieve the visit data correctly. Is there any minimum hardware requirement or compatibility issue with certain models or configurations that I should be aware of for using SensorKit visits? Any guidance or insight would be greatly appreciated! Thank you.

The Deligate 'didFetchResult' method of fetching data past 24 hours from SensorKit is not being called. It is confirmed that you have already granted full access to the SensorKit and that data on the Ambient value in the device's personal information -> research sensor & usage data are recorded. It is possible to export to an lz4 file. I want to have the data after 24 hours called to the app, but other Deligate methods are called, but only Deligate that gets the illumination value is not called. Is it understood that only data past 24 hours can be imported after startRecoding() is called? If so, in order to receive data past 24 hours, do I have to continue to receive the illumination data value in the background for more than 24 hours to receive the Ambient value afterwards? import Foundation import SensorKit import UIKit final class SensorKitManager: NSObject, ObservableObject, SRSensorReaderDelegate { static let shared = SensorKitManager() private let ambientReader = SRSensorReader(sensor: .ambientLightSensor) var availableDevices: [SRDevice] = [] @Published var ambientLightData: [AmbientLightDataPoint] = [] var isFetching = false var isRecordingAmbientLight = false private override init() { super.init() setupReaders() checkAndRequestAuthorization() } private func setupReaders() { ambientReader.delegate = self } // MARK: - Permission Request func requestAuthorization() { SRSensorReader.requestAuthorization(sensors: [.ambientLightSensor]) { [weak self] error in DispatchQueue.main.async { guard let self = self else { print("Permission request aborted") return } if let error = error { print("Permission request failed: \(error.localizedDescription)") } else { print("Permission request succeeded") self.startRecordingAmbientLightData() } } } } func checkAndRequestAuthorization() { let status = ambientReader.authorizationStatus switch status { case .authorized: print("Ambient light sensor access granted") startRecordingAmbientLightData() case .notDetermined: print("Ambient light sensor access undetermined, requesting permission") requestAuthorization() case .denied: print("Ambient light sensor access denied or restricted") @unknown default: print("Unknown authorization status") } } // MARK: - Ambient Light Data Logic func startRecordingAmbientLightData() { guard !isRecordingAmbientLight else { print("Already recording ambient light data.") return } print("Starting ambient light data recording") isRecordingAmbientLight = true ambientReader.startRecording() fetchAmbientLightData() fetchAmbientDeviceData() } func fetchAmbientLightData() { print("Fetching ambient light data") let request = SRFetchRequest() let now = Date() let fromTime = now.addingTimeInterval(-72 * 60 * 60) let toTime = now.addingTimeInterval(-25 * 60 * 60) request.from = SRAbsoluteTime(fromTime.timeIntervalSinceReferenceDate) request.to = SRAbsoluteTime(toTime.timeIntervalSinceReferenceDate) print("Fetch request: \(fromTime) ~ \(toTime)") ambientReader.fetch(request) } private func displayAmbientLightData(sample: SRAmbientLightSample) { print("Ambient light: \(sample.lux.value) lux") print("Current ambientLightData content:") for data in ambientLightData { print("Timestamp: \(data.timestamp), Lux: \(data.lux)") } } // MARK: - Device Data Logic private func fetchAmbientDeviceData() { print("Fetching device information") let request = SRFetchRequest() let now = Date() let fromDate = now.addingTimeInterval(-72 * 60 * 60) let toDate = now.addingTimeInterval(-24 * 60 * 60) request.from = SRAbsoluteTime(fromDate.timeIntervalSinceReferenceDate) request.to = SRAbsoluteTime(toDate.timeIntervalSinceReferenceDate) if availableDevices.isEmpty { print("No devices available") ambientReader.fetchDevices() } else { for device in availableDevices { print("Starting data fetch (Device: \(device))") request.device = device ambientReader.fetch(request) print("Fetch request sent (Device: \(device))") } } } // MARK: - SRSensorReaderDelegate Methods func sensorReader(_ reader: SRSensorReader, didFetch devices: [SRDevice]) { availableDevices = devices for device in devices { print("Fetched device: \(device)") } if !devices.isEmpty { fetchAmbientDeviceData() } } func sensorReader(_ reader: SRSensorReader, fetching fetchRequest: SRFetchRequest, didFetchResult result: SRFetchResult<AnyObject>) -> Bool { print("sensorReader(_:fetching:didFetchResult:) method called") if let ambientSample = result.sample as? SRAmbientLightSample { let luxValue = ambientSample.lux.value let timestamp = Date(timeIntervalSinceReferenceDate: result.timestamp.rawValue) // Check for duplicate data and add it if !ambientLightData.contains(where: { $0.timestamp == timestamp }) { let dataPoint = AmbientLightDataPoint(timestamp: timestamp, lux: Float(luxValue)) ambientLightData.append(dataPoint) print("Added ambient light data: \(luxValue) lux, Timestamp: \(timestamp)") } else { print("Duplicate data, not adding: Timestamp: \(timestamp)") } // Output data self.displayAmbientLightData(sample: ambientSample) } return true } func sensorReader(_ reader: SRSensorReader, didCompleteFetch fetchRequest: SRFetchRequest) { print("Data fetch complete") if ambientLightData.isEmpty { print("No ambient light data within 24 hours.") } else { print("ambientLightData updated") for dataPoint in ambientLightData { print("Added ambient light data: \(dataPoint.lux) lux, Timestamp: \(dataPoint.timestamp)") } } } }