How to Save Heart Rate in HKCategoryTypeIdentifier.mindfulSession

Question

Created Mar ’25

Replies 1

Boosts 0

Participants 2

I’m trying to associate heart rate (HR) data with a mindfulness session (HKCategoryTypeIdentifier.mindfulSession) in HealthKit, but I can’t find any documentation on how to do this.

I’ve seen third-party apps (like Medito) successfully log HR within Mindful Minutes, even when the session takes place on an iPhone (not an Apple Watch). However, when I try saving HR in the metadata, it does not appear in the Health app's Mindful Minutes section.

Code snippet:

 func logMindfulnessSession(start: Bool, heartRate: Double? = nil) {
    let mindfulType = HKCategoryType.categoryType(forIdentifier: .mindfulSession)!
    let now = Date()
    let endTime = now.addingTimeInterval(Double(selectedDuration))
 
    var metadata: [String: Any]? = nil
    if let hr = heartRate {
        let heartRateUnit = HKUnit.count().unitDivided(by: HKUnit.minute())
        let hrQuantity = HKQuantity(unit: heartRateUnit, doubleValue: hr)
        metadata = ["heartRate": hrQuantity]  // ❓ Is there a correct key for HR?
    }
 
    let sample = HKCategorySample(
        type: mindfulType,
        value: 0,
        start: now,
        end: endTime,
        metadata: metadata
    )
 
    healthStore.save(sample) { success, error in
        if let error = error {
            print("HealthKit session save error: \(error.localizedDescription)")
        } else {
            print("Mindfulness session saved successfully.")
            if let hr = heartRate {
                print("Saved with HR: \(hr) BPM")
            }
        }
    }
}

Questions:

What is the correct metadata key for associating heart rate with a mindful session?
Does HealthKit require a specific format (e.g., HKQuantitySample) for HR?

0 Are there additional permissions needed to allow HR to appear in Mindful Minutes?

Does HR need to be stored separately in HKQuantityTypeIdentifier.heartRate, and if so, how do third-party apps ensure it appears in the same entry as the mindful session?

thank you!

Answered by DTS Engineer in 827892022

I don't think we expose any metadata key that can tie a heart rate to a mindful session as of today, but if you create a heart rate sample that is aligned to the time of the mindful session, as shown in the following code, the heart rate will show up in the Finess.app:

 let endTime = Date()
let startTime = endTime.addingTimeInterval(-60 * 1)
 
let mindfulSessionSample = HKCategorySample(
    type: HKCategoryType(.mindfulSession),
    value: 0, start: startTime, end: endTime, metadata: nil
)
 
let heartRateUnit = HKUnit.count().unitDivided(by: HKUnit.minute())
let hrQuantity = HKQuantity(unit: heartRateUnit, doubleValue: 56)
let heartRateSample = HKQuantitySample(
    type: HKQuantityType(.heartRate),
    quantity: hrQuantity, start: startTime, end: startTime
)
 
healthStore.save([mindfulSessionSample, heartRateSample]) { success, error in
    if let error = error {
        print("HealthKit session save error: \(error.localizedDescription)")
    } else {
        print("Mindfulness session saved successfully.")
    }
}

Note that you need to have the user authorization to write / share the following HealthKit data types:

 HKQuantityType(.heartRate),
HKCategoryType(.mindfulSession)

Best,
——
Ziqiao Chen
 Worldwide Developer Relations.

Boost

Answer 1

DTS Engineer OP

Apple

Mar ’25

Recommended

I don't think we expose any metadata key that can tie a heart rate to a mindful session as of today, but if you create a heart rate sample that is aligned to the time of the mindful session, as shown in the following code, the heart rate will show up in the Finess.app:

 let endTime = Date()
let startTime = endTime.addingTimeInterval(-60 * 1)
 
let mindfulSessionSample = HKCategorySample(
    type: HKCategoryType(.mindfulSession),
    value: 0, start: startTime, end: endTime, metadata: nil
)
 
let heartRateUnit = HKUnit.count().unitDivided(by: HKUnit.minute())
let hrQuantity = HKQuantity(unit: heartRateUnit, doubleValue: 56)
let heartRateSample = HKQuantitySample(
    type: HKQuantityType(.heartRate),
    quantity: hrQuantity, start: startTime, end: startTime
)
 
healthStore.save([mindfulSessionSample, heartRateSample]) { success, error in
    if let error = error {
        print("HealthKit session save error: \(error.localizedDescription)")
    } else {
        print("Mindfulness session saved successfully.")
    }
}

Note that you need to have the user authorization to write / share the following HealthKit data types:

 HKQuantityType(.heartRate),
HKCategoryType(.mindfulSession)

Best,
——
Ziqiao Chen
 Worldwide Developer Relations.

0

	func logMindfulnessSession(start: Bool, heartRate: Double? = nil) {
	let mindfulType = HKCategoryType.categoryType(forIdentifier: .mindfulSession)!
	let now = Date()
	let endTime = now.addingTimeInterval(Double(selectedDuration))

	var metadata: [String: Any]? = nil
	if let hr = heartRate {
	let heartRateUnit = HKUnit.count().unitDivided(by: HKUnit.minute())
	let hrQuantity = HKQuantity(unit: heartRateUnit, doubleValue: hr)
	metadata = ["heartRate": hrQuantity] // ❓ Is there a correct key for HR?
	}

	let sample = HKCategorySample(
	type: mindfulType,
	value: 0,
	start: now,
	end: endTime,
	metadata: metadata
	)

	healthStore.save(sample) { success, error in
	if let error = error {
	print("HealthKit session save error: \(error.localizedDescription)")
	} else {
	print("Mindfulness session saved successfully.")
	if let hr = heartRate {
	print("Saved with HR: \(hr) BPM")
	}
	}
	}
	}

	let endTime = Date()
	let startTime = endTime.addingTimeInterval(-60 * 1)

	let mindfulSessionSample = HKCategorySample(
	type: HKCategoryType(.mindfulSession),
	value: 0, start: startTime, end: endTime, metadata: nil
	)

	let heartRateUnit = HKUnit.count().unitDivided(by: HKUnit.minute())
	let hrQuantity = HKQuantity(unit: heartRateUnit, doubleValue: 56)
	let heartRateSample = HKQuantitySample(
	type: HKQuantityType(.heartRate),
	quantity: hrQuantity, start: startTime, end: startTime
	)

	healthStore.save([mindfulSessionSample, heartRateSample]) { success, error in
	if let error = error {
	print("HealthKit session save error: \(error.localizedDescription)")
	} else {
	print("Mindfulness session saved successfully.")
	}
	}