Read Sleep Data

  • Sleep data in Google Fit is stored as sessions of type sleep and can optionally contain detailed sleep stage information.

  • Sleep stages are categorized with specific values, such as 1 for awake, 4 for light sleep, and 6 for REM sleep.

  • Android developers can use the SessionClient and SessionReadRequest to retrieve both basic and detailed sleep data.

  • REST API access involves a two-step process: retrieving a list of sleep sessions, then requesting detailed sleep stage data for each session if available.

  • Sleep stage details from the REST API are provided as intVal values within the response, corresponding to the sleep stage categories.

Sleep is represented by sessions of type sleep. Sessions can optionally contain sleep stages, which have more granular details about sleep data. For example, if it was light, deep or REM sleep:

Sleep stage values
Sleep stage type Value
Awake (during sleep cycle) 1
Sleep 2
Out-of-bed 3
Light sleep 4
Deep sleep 5
REM 6

The write sleep data guide shows how both granular and non-granular sleep data is represented in Fit.

Android

The follow samples uses a SessionClient to retrieve data from Fit, for both cases.

val SLEEP_STAGE_NAMES = arrayOf(
    "Unused",
    "Awake (during sleep)",
    "Sleep",
    "Out-of-bed",
    "Light sleep",
    "Deep sleep",
    "REM sleep"
)

val request = SessionReadRequest.Builder()
    .readSessionsFromAllApps()
    // By default, only activity sessions are included, so it is necessary to explicitly
    // request sleep sessions. This will cause activity sessions to be *excluded*.
    .includeSleepSessions()
    // Sleep segment data is required for details of the fine-granularity sleep, if it is present.
    .read(DataType.TYPE_SLEEP_SEGMENT)
    .setTimeInterval(startTime, endTime, TimeUnit.MILLISECONDS)
    .build()

sessionsClient.readSession(request)
    .addOnSuccessListener { response ->
        for (session in response.sessions) {
            val sessionStart = session.getStartTime(TimeUnit.MILLISECONDS)
            val sessionEnd = session.getEndTime(TimeUnit.MILLISECONDS)
            Log.i(TAG, "Sleep between $sessionStart and $sessionEnd")

            // If the sleep session has finer granularity sub-components, extract them:
            val dataSets = response.getDataSet(session)
            for (dataSet in dataSets) {
                for (point in dataSet.dataPoints) {
                    val sleepStageVal = point.getValue(Field.FIELD_SLEEP_SEGMENT_TYPE).asInt()
                    val sleepStage = SLEEP_STAGE_NAMES[sleepStageVal]
                    val segmentStart = point.getStartTime(TimeUnit.MILLISECONDS)
                    val segmentEnd = point.getEndTime(TimeUnit.MILLISECONDS)
                    Log.i(TAG, "\t* Type $sleepStage between $segmentStart and $segmentEnd")
                }
            }
        }
    }

REST

Retrieving sleep sessions using the REST API is a two stage process:

  1. Retrieve a list of sessions setting the activityType parameter to 72 (SLEEP). Note: You can use a startTime and endTime, or use a pageToken to retrieve new sessions since the previous request.

    HTTP method

    GET

    Request URL

    https://www.googleapis.com/fitness/v1/users/me/sessions?startTime=2019-12-05T00:00.000Z&endTime=2019-12-17T23:59:59.999Z&activityType=72

    Response

    An example Session response might be:

    {
 "session": [
    {
     "id": "Sleep1575505620000",
     "name": "Sleep",
     "description": "",
     "startTimeMillis": "1575505620000",
     "endTimeMillis": "1575526800000",
     "modifiedTimeMillis": "1575590432413",
     "application": {
      "packageName": "com.example.sleep_tracker"
     },
     "activityType": 72  // Sleep
    },
    {
     "id": "Run2939075083",
     "name": "Mud",
     "description": "",
     "startTimeMillis": "1576594403000",
     "endTimeMillis": "1576598754000",
     "modifiedTimeMillis": "1576616010143",
     "application": {
      "packageName": "com.example.run_tracker"
     },
     "activityType": 8  // Running
    }
  ],
 "deletedSession": [],
 "nextPageToken": "1576598754001"
}

  2. To obtain details of sleep stages for each session (if present), use the following request for each session in the filtered list:

    HTTP method

    POST

    Request URL

    https://www.googleapis.com/fitness/v1/users/userId/dataset:aggregate

    Request body

    {
  "aggregateBy": [
    {
      "dataTypeName": "com.google.sleep.segment"
    }
  ],
  "endTimeMillis": 1575609060000,
  "startTimeMillis": 1575591360000
}

    Response

    If your request was successful, you'll get a 200 OK HTTP response status code. The response body contains a JSON representation of activity segments that comprise the sleep session. Each intVal represents the sleep activity type

    {
 "bucket": [
  {
   "startTimeMillis": "1575591360000",
   "endTimeMillis": "1575609060000",
   "dataset": [
    {
     "point": [
      {
       "startTimeNanos": "1575591360000000000",
       "endTimeNanos": "1575595020000000000",
       "dataTypeName": "com.google.sleep.segment",
       "originDataSourceId": "...",
       "value": [
        {
         "intVal": 4, // Light sleep
         "mapVal": []
        }
       ]
      },
      {
       "startTimeNanos": "1575595020000000000",
       "endTimeNanos": "1575596220000000000",
       "dataTypeName": "com.google.sleep.segment",
       "originDataSourceId": "...",
       "value": [
        {
         "intVal": 1, // Sleep
         "mapVal": []
        }
       ]
      },

      // .... more datapoints

      {
       "startTimeNanos": "1575605940000000000",
       "endTimeNanos": "1575609060000000000",
       "dataTypeName": "com.google.sleep.segment",
       "originDataSourceId": "...",
       "value": [
        {
         "intVal": 4, // Light sleep
         "mapVal": []
        }
       ]
      }
     ]
    }
   ]
  }
 ]
}