---
title: Biomarkers
---


## Overview

Sahha analyzes user data such as sleep, steps and more to create daily biomarkers which you can display to your users.

Use the the `getBiomarkers` method to return a variety of [Sahha Digital Biomarkers](/docs/products/biomarkers).

Consider exploring our [design principles](https://resources.sahha.ai/industry/) for best practices around displaying Sahha data.

{% callout title="Biomarker Categories and Types" %}

Every biomarker has both a category and type.

**To use `getBiomarkers` you must include both the category and type of that biomarker.**

A complete list of biomarker categories and types [can be found here](/docs/products/biomarkers#list-of-biomarkers).

{% /callout %}

---

## Get biomarkers for today

Get the most recent biomarkers for the current day in the user's local timezone.

{% tabs %}

{% tab label="iOS" %}

```swift title=MyApp.swift
// Get biomarkers for last 24 hours

Sahha.getBiomarkers(
  categories: [.activity, .sleep, .vitals],
  types: [.steps, .sleep_duration, .heart_rate],
  startDateTime: .now,
  endDateTime: .now)
  { error, json in
    if let error = error {
        print(error)
    } else if let json = json {
        print(json)
    }
}
```

{% /tab %}

{% tab label="Android" %}

```kotlin title=MainActivity.kt
// Get biomarkers for last 24 hours
// Leave date range empty

Sahha.getBiomarkers(
  categories = setOf(SahhaBiomarkerCategory.activity, SahhaBiomarkerCategory.sleep, SahhaBiomarkerCategory.vitals),
  types = setOf(SahhaBiomarkerType.steps, SahhaBiomarkerType.sleep_duration, SahhaBiomarkerType.heart_rate)
) { error, success ->
  error?.also {
    println(error)
  }
  success?.also {
    println(success)
  }
}
```

{% /tab %}

{% tab label="Flutter" %}

```typescript title=MyApp.dart
// Get biomarkers for last 24 hours
// Leave date range empty

SahhaFlutter.getBiomarkers(
  categories: [SahhaBiomarkerCategory.activity, SahhaBiomarkerCategory.sleep, SahhaBiomarkerCategory.vitals],
  types: [SahhaBiomarkerType.steps, SahhaBiomarkerType.sleep_duration, SahhaBiomarkerType.heart_rate],
  startDateTime: DateTime.now(),
  endDateTime: DateTime.now())
.then((value) {
    List<dynamic> data = jsonDecode(value);
    debugPrint(data.toString());
}).catchError((error, stackTrace) => {debugPrint(error.toString())});
```

{% /tab %}

{% tab label="React Native" %}

```typescript title=MyApp.tsx
// Get biomarkers for last 24 hours
// Leave date range empty

let date = new Date();

Sahha.getBiomarkers(
	[SahhaBiomarkerCategory.activity, SahhaBiomarkerCategory.sleep, SahhaBiomarkerCategory.vitals],
	[SahhaBiomarkerType.steps, SahhaBiomarkerType.sleep_duration, SahhaBiomarkerType.heart_rate],
	date.getTime(),
	date.getTime(),
	(error: string, value: string) => {
		if (error) {
			console.error(`Error: ${error}`);
		} else if (value) {
			const jsonArray = JSON.parse(value);
			const jsonString = JSON.stringify(jsonArray);
			console.log(jsonString);
		}
	}
);
```

{% /tab %}

{% tab label="Ionic Capacitor" %}

```javascript title=MyApp.js
// Get biomarkers for last 24 hours
// Leave date range empty

let date: Date = new Date();

Sahha.getBiomarkers({
	categories: [SahhaBiomarkerCategory.activity, SahhaBiomarkerCategory.sleep, SahhaBiomarkerCategory.vitals],
  types: [SahhaBiomarkerType.steps, SahhaBiomarkerType.sleep_duration, SahhaBiomarkerType.heart_rate],
	startDateTime: date.getTime(),
	endDateTime: date.getTime() })
.then(
    function (response) {
        const jsonArray = JSON.parse(response.value);
        const jsonString = JSON.stringify(jsonArray);
        console.log(jsonString);
    },
    function (error) {
        console.log(error);
    }
)
```

{% /tab %}

{% /tabs %}

---

## Get biomarkers for the last week

You can provide a data range if you would like to receive multiple biomarkers over a specific time period. The response will include an array of biomarkers for each 24 hour segment in that time period.

{% tabs %}

{% tab label="iOS" %}

```swift title=MyApp.swift
// Get biomarkers for last 7 days
// Add a date range

let today = Date()
let sevenDaysAgo = Calendar.current.date(byAdding: .day, value: -7, to: today) ?? Date()

Sahha.getBiomarkers(
  categories: [.activity, .sleep, .vitals],
  types: [.steps, .sleep_duration, .heart_rate],
  startDateTime: sevenDaysAgo, endDateTime: today
) { error, json in
    if let error = error {
        print(error)
    } else if let json = json {
        print(json)
    }
}
```

{% /tab %}

{% tab label="Android" %}

```kotlin title=MainActivity.kt
// Get biomarkers for last 7 days
// Add a date range

Sahha.getBiomarkers(
  categories = setOf(SahhaBiomarkerCategory.activity, SahhaBiomarkerCategory.sleep, SahhaBiomarkerCategory.vitals),
  types = setOf(SahhaBiomarkerType.steps, SahhaBiomarkerType.sleep_duration, SahhaBiomarkerType.heart_rate),
  dates = Pair(LocalDateTime.now().minusDays(7), LocalDateTime.now()),
) { error, success ->
  error?.also {
    println(error)
  }
  success?.also {
    println(success)
  }
}
```

{% /tab %}

{% tab label="Flutter" %}

```typescript title=MyApp.dart
// Get biomarkers for last 7 days
// Add a date range

SahhaFlutter.getBiomarkers(
  categories: [SahhaBiomarkerCategory.activity, SahhaBiomarkerCategory.sleep, SahhaBiomarkerCategory.vitals],
  types: [SahhaBiomarkerType.steps, SahhaBiomarkerType.sleep_duration, SahhaBiomarkerType.heart_rate],
  startDateTime: DateTime.now().subtract(const Duration(days: 7)),
  endDateTime: DateTime.now())
.then((value) {
  List<dynamic> data = jsonDecode(value);
  debugPrint(data.toString());
}).catchError((error, stackTrace) => {debugPrint(error.toString())});
```

{% /tab %}

{% tab label="React Native" %}

```typescript title=MyApp.tsx
// Get biomarkers for last 7 days
// Add date range as milliseconds since epoch time

let endDate: Date = new Date();
let sevenDaysAgo = endDate.getDate() - 7;
var startDate = new Date();
startDate.setDate(sevenDaysAgo);

Sahha.getBiomarkers(
	[SahhaBiomarkerCategory.activity, SahhaBiomarkerCategory.sleep, SahhaBiomarkerCategory.vitals],
	[SahhaBiomarkerType.steps, SahhaBiomarkerType.sleep_duration, SahhaBiomarkerType.heart_rate],
	startDate.getTime(),
	endDate.getTime(),
	(error: string, value: string) => {
		if (error) {
			console.error(`Error: ${error}`);
		} else if (value) {
			const jsonArray = JSON.parse(value);
			const jsonString = JSON.stringify(jsonArray);
			console.log(jsonString);
		}
	}
);
```

{% /tab %}

{% tab label="Ionic Capacitor" %}

```javascript title=MyApp.js
// Get biomarkers for last 7 days
// Add date range as milliseconds since epoch time

let endDate: Date = new Date();
let sevenDaysAgo = endDate.getDate() - 7;
var startDate = new Date();
startDate.setDate(sevenDaysAgo);

Sahha.getBiomarkers({
	categories: [SahhaBiomarkerCategory.activity, SahhaBiomarkerCategory.sleep, SahhaBiomarkerCategory.vitals],
  types: [SahhaBiomarkerType.steps, SahhaBiomarkerType.sleep_duration, SahhaBiomarkerType.heart_rate],
	startDateTime: startDate.getTime(),
	endDateTime: endDate.getTime() })
.then(
    function (response) {
        const jsonArray = JSON.parse(response.value);
        const jsonString = JSON.stringify(jsonArray);
        console.log(jsonString);
    },
    function (error) {
        console.log(error);
    }
)
```

{% /tab %}

{% /tabs %}

---

## Biomarker response

Biomarkers are generated via the Sahha API.

Biomarkers are returned as an array of objects in JSON format.

- **Parameters**:
  - `id`: UUID for the sample
  - `category`: The category of the biomarker (`activity`, `sleep`, etc.)
  - `type`: The type of the biomarker (`steps`, `sleep_start_time`, etc.)
  - `startDateTime`: Start date-time in `"yyyy-MM-dd'T'HH:mm:ss.SSZZZZZ"` format (`"2021-10-27T16:34:06-06:00"`)
  - `endDateTime`: End date-time in `"yyyy-MM-dd'T'HH:mm:ss.SSZZZZZ"` format (`"2021-10-27T16:44:06-06:00"`)
  - `periodicity`: The periodicity of the biomarker (`hourly`, `daily`, `weekly`, etc.)
    `aggregation`: The aggregation of the biomarker (`total`, `average`, etc.)
  - `value`: Value of the biomarker (`100`, `200`, etc.)
  - `valueType`: The type of value of the biomarker (`long`, `double`, `datetime`, etc.)
  - `unit`: The unit for measuring the value (`count`, `minute`, `kg`, `bpm`, etc.)

### Array response

The response will be in JSON format. An example response includes these fields:

```json title=RESPONSE
[
	{
		"id": "ca4f0f27-b972-55e6-b401-617dbd0030ba",
		"category": "activity",
		"type": "active_hours",
		"periodicity": "daily",
		"aggregation": "total",
		"value": "1",
		"unit": "hour",
		"valueType": "long",
		"startDateTime": "2024-12-16T15:00:00+00:00",
		"endDateTime": "2024-12-17T14:59:59+00:00"
	},
	{
		"id": "73f15c2d-fae6-5239-a040-80f7429d2d1c",
		"category": "sleep",
		"type": "sleep_duration",
		"periodicity": "daily",
		"aggregation": "total",
		"value": "439",
		"unit": "minute",
		"valueType": "long",
		"startDateTime": "2024-12-16T09:00:00+00:00",
		"endDateTime": "2024-12-17T08:59:59+00:00"
	},
	{
		"id": "82cbebfd-0452-577e-b1dc-e076541bad70",
		"category": "sleep",
		"type": "sleep_end_time",
		"periodicity": "daily",
		"aggregation": "none",
		"value": "2024-12-17T07:58:56+09:00",
		"unit": "datetime",
		"valueType": "datetime",
		"startDateTime": "2024-12-16T09:00:00+00:00",
		"endDateTime": "2024-12-17T08:59:59+00:00"
	},
	{
		"id": "089a57fb-11bc-5c08-9180-cebd090e5771",
		"category": "sleep",
		"type": "sleep_efficiency",
		"periodicity": "daily",
		"aggregation": "none",
		"value": "0.988",
		"unit": "percentage",
		"valueType": "double",
		"startDateTime": "2024-12-16T09:00:00+00:00",
		"endDateTime": "2024-12-17T08:59:59+00:00"
	},
	{
		"id": "4ba012c7-9a31-5368-83f9-c22d12a13f15",
		"category": "sleep",
		"type": "sleep_latency",
		"periodicity": "daily",
		"aggregation": "none",
		"value": "0",
		"unit": "minute",
		"valueType": "long",
		"startDateTime": "2024-12-16T09:00:00+00:00",
		"endDateTime": "2024-12-17T08:59:59+00:00"
	},
	{
		"id": "84d31d96-abbe-5e19-a664-7728a86aee33",
		"category": "vitals",
		"type": "oxygen_saturation",
		"periodicity": "daily",
		"aggregation": "average",
		"value": "0.976666666666667",
		"unit": "percentage",
		"valueType": "double",
		"startDateTime": "2024-12-17T15:00:00+00:00",
		"endDateTime": "2024-12-18T14:59:59+00:00"
	},
	{
		"id": "4676bfee-0ca1-5616-a711-0d75e07ba58d",
		"category": "vitals",
		"type": "heart_rate_sleep",
		"periodicity": "daily",
		"aggregation": "average",
		"value": "72",
		"unit": "bpm",
		"valueType": "long",
		"startDateTime": "2024-12-17T15:00:00+00:00",
		"endDateTime": "2024-12-18T14:59:59+00:00"
	},
	{
		"id": "4e46a8a2-9d4f-53cd-9e15-e84f80e21e43",
		"category": "vitals",
		"type": "skin_temperature_sleep",
		"periodicity": "daily",
		"aggregation": "average",
		"value": "36.5630722045898",
		"unit": "celsius",
		"valueType": "double",
		"startDateTime": "2024-12-18T15:00:00+00:00",
		"endDateTime": "2024-12-19T14:59:59+00:00"
	},
	{
		"id": "8727cd3b-2890-56b3-8586-048982182b9f",
		"category": "vitals",
		"type": "oxygen_saturation",
		"periodicity": "daily",
		"aggregation": "average",
		"value": "0.967857142857143",
		"unit": "percentage",
		"valueType": "double",
		"startDateTime": "2024-12-18T15:00:00+00:00",
		"endDateTime": "2024-12-19T14:59:59+00:00"
	},
	{
		"id": "376797f4-2068-5b42-90e2-53b575c40bc6",
		"category": "vitals",
		"type": "oxygen_saturation_sleep",
		"periodicity": "daily",
		"aggregation": "average",
		"value": "0.965",
		"unit": "percentage",
		"valueType": "double",
		"startDateTime": "2024-12-18T15:00:00+00:00",
		"endDateTime": "2024-12-19T14:59:59+00:00"
	},
	{
		"id": "b9076521-a09d-5624-9784-2f51a85d4c89",
		"category": "vitals",
		"type": "heart_rate_variability_sdnn",
		"periodicity": "daily",
		"aggregation": "average",
		"value": "47.8524671307249",
		"unit": "millisecond",
		"valueType": "double",
		"startDateTime": "2024-12-18T15:00:00+00:00",
		"endDateTime": "2024-12-19T14:59:59+00:00"
	},
	{
		"id": "93b34b6f-8a5e-5edd-ac0d-b6a5107a39c2",
		"category": "vitals",
		"type": "heart_rate_sleep",
		"periodicity": "daily",
		"aggregation": "average",
		"value": "66",
		"unit": "bpm",
		"valueType": "long",
		"startDateTime": "2024-12-18T15:00:00+00:00",
		"endDateTime": "2024-12-19T14:59:59+00:00"
	}
]
```

### Empty response

An empty JSON but successful response.

{% callout title="MINIMUM DATA REQUIREMENTS" %}

The analysis engine requires a minimum amount of device sensor data to be uploaded and processed before an analysis can be determined.

If you call `getBiomarkers` for a new user profile or a user that has been inactive lately, it's possible for the response to be `204 No Content`. This is not an error.

**You will need to wait and try again every few hours until a biomarker is available.**
{% /callout %}

```json title=RESPONSE
// A biomarker is not ready yet
// Try again in a few hours
// Empty JSON
{}
```

---

## Data sources

Data sources are required to generate a biomarker.

{% callout title="The biomarker is created from various data sources" %}

To receive a biomarker, a minimum of one data source must be configured by the SDK.

The more data sources that you configure via the SDK, the better the biomarker that will be generated.

Some data sources are not yet available on all platforms. Sahha continues to improve its analysis engine by bringing feature parity between platforms as well as adding new data sources.

{% /callout %}

| Data Source | Description             | Android | iOS |
| ----------- | ----------------------- | :-----: | :-: |
| sleep       | User sleep patterns     |    ✓    |  ✓  |
| steps       | User walking patterns   |    ✓    |  ✓  |
| screen      | User device screen time |    ✓    |  X  |
| heart       | User heart patterns     |    ✓    |  ✓  |
| blood       | User blood patterns     |    ✓    |  ✓  |
| age         | User age                |    ✓    |  ✓  |
| gender      | User gender             |    ✓    |  ✓  |

---

### Device sensors

{% callout title="Use Sensors as a Data Source" %}

Learn how to configure device sensors to collect data.

[Configure Sensors](/docs/connect/sdk/collection)
{% /callout %}

---

### Demographics

{% callout title="Use Demographics as a Data Source" %}

Learn how to configure demographics as a data source.

[Configure Demographics](/docs/connect/sdk/data/demographics)
{% /callout %}