MongoDB Realm Android SDK

The MongoDB Realm Android SDK enables client applications on the Android platform to access data stored in local realms and interact with MongoDB Realm services like Functions, MongoDB Data Access, and authentication. The Android SDK supports both Java and Kotlin Android applications.


The Android SDK does not support Java or Kotlin applications written for environments other than Android.


To learn how to add the MongoDB Realm Android SDK library as a dependency to your Android application, see Install Realm for Android.

The Realm Data Model

You can store a wide variety of data within realms stored on your device. With Realm Sync, you can share updates to that data across client devices and MongoDB Atlas.

For information about the structure of data you can store in realms, see Realms, Objects, and Relationships.

To learn about the results returned from realm queries, see Collections.

Work with Realm Database

Once you have defined a data model for your application, you need to be able to write and read pieces of data to and from your realms.

To learn how to query for data in local realms, see Query Engine.

For advice on how to safely interact with Realm Database across threads in an application, see Threading.

For information about how to react to changes in realm data, see Notifications.

Work with MongoDB Realm

The Android SDK also connects your Realm client application with your Realm app’s backend services, including Functions, Services, Webhooks, Realm Sync, and built-in third-party authentication.

To learn how to connect to a MongoDB Realm app to call Functions, query data in an instance of MongoDB Atlas, and synchronize data in realms, see Call a Function.

To learn how to authenticate a user using the Android SDK, see Authentication.

To learn how to handle schema updates in your client application, see Migrations.