Data types

Google Fit provides a set of health and wellness data types under the com.google namespace.

Data types define the format of the values inside data points. A data point can represent:

• An instantaneous reading or observation
• An aggregate with statistics over a time interval

Google Fit defines data types for instantaneous observations and data types for aggregate data. Data points consist of values for the fields of a data type and timestamp information. Points that represent instantaneous observations include a timestamp, and points of an aggregate data type also include the start time for the interval.

Google Fit also lets you define new data types.

Data type groups

Google Fit has these data types:

Public data types

Standard data types provided by the platform have the 'com.google' prefix. For example, com.google.step_count.delta. These data types capture instant readings for health and wellness data, including fitness activity, sleep and nutrition. Any app can request the relevant permissions to read and write to these data types, except for a few location data types which can only be read by the app that wrote them.

For more information, see:

• Activity data types
• Location data types
• Nutrition data types

Health data types

Data types provided by the platform that have restricted access due to potentially sensitive data. For more information, see Health data types.

Aggregate data types

Data types to read health and wellness information aggregated by time or activity type. For more information, see Aggregate data types.

Private custom data types

Custom data types defined by a specific app. Only the app that defines the data type can read and write data of this type. For more information, see Custom data types.

Using data types

val nutritionSource = DataSource.Builder()
    .setDataType(DataType.TYPE_NUTRITION)
    ...
    .build()

val nutrients = mapOf(
    Field.NUTRIENT_TOTAL_FAT to 0.4f,
    Field.NUTRIENT_SODIUM to 1f,
    Field.NUTRIENT_POTASSIUM to 422f
)
val banana = DataPoint.builder(nutritionSource)
    .setTimestamp(now, TimeUnit.MILLISECONDS)
    .setField(Field.FIELD_FOOD_ITEM, "banana")
    .setField(Field.FIELD_MEAL_TYPE, Field.MEAL_TYPE_SNACK)
    .setField(Field.FIELD_NUTRIENTS, nutrients)
    .build()

{
"dataStreamId": "exampleDataSourceId",
...
"dataType": {
  "name": "com.google.step_count.delta"
},
...
}

Authorization scopes

Authorization scopes cover groups of data types that a user can authorize an app to access. They help users understand what kinds of data an app wants to access. They also make it easier to give apps permission to use that data by not having to approve each individual data type. Users grant these permissions once they've downloaded your app.

After you've tested your app with a small number of users, before launching your app you need to request verification based on the scopes relevant to those data types. Read through the data types pages linked above to understand which scopes apply to each data type.

For example, if your app needs to read and write writing blood pressure, it needs to declare it's doing both read and write and request both scopes. If it's only writing blood pressure data to the Google Fit platform, it only needs to request the write scope.

Choose data types responsibly. Don't request every data type in case your app might need it. The types specified determine which scopes the user is prompted to grant permission for. Only ask for the data types your app needs so users are more likely to grant access. Users more readily grant access to limited, clearly described scopes.

Use this table to check if the scopes your app needs access to are sensitive or restricted (which determines the verification steps you'll need to follow):

Adding new scopes to an existing app

When you update your app to request a new scope (for example, if you add the new sleep or heart rate scopes, or add a read scope), users will be prompted that your app is requesting access to these scopes and they can choose to grant or reject access.

It's best practice to request authorization from users for resources at the time you need them. Follow the guidelines on requesting incremental authorization.

Users will be more likely to grant access if they understand why/how your app uses this data:

• Consider adding a screen that warns/informs users that they'll be asked for these scopes.
• Clearly explain why your app is asking for access to these scopes/data so users can make an informed decision.

Learn more about best practices around app permissions for Android.