Android Studio

Android API reference

Start building your Android app with the Android Platform APIs. They are available in Kotlin and Java.

Note: Many Kotlin reference topics are derived from Java-based source code. This means that some Kotlin reference topics might contain Java code snippets.

These additional libraries make it easy to add additional functionality and features to your app.

Jetpack

AndroidX
Refactored versions of the Android APIs that are not bundled with the operating system.
Reference  User Guide
Jetpack Compose
Jetpack Compose is a modern toolkit for building native Android UI. Jetpack Compose simplifies and accelerates UI development on Android with less code, powerful tools, and intuitive Kotlin APIs.
Reference  User Guide
AndroidX Constraint Layout
Includes ConstraintLayout and related APIs for building constraint-based layouts.
Reference  User Guide
For ConstraintLayout in Compose.
Reference
Databinding Library
Includes APIs to help you write declarative layouts and minimize the glue code necessary to bind your application logic and layouts.
Reference  User Guide

Device Libraries

Android Automotive Library
Provides APIs for building Android Automotive apps.
Reference  User Guide
Watch Face Format
Provides APIs for creating watch faces on Wear OS devices.
Reference  User Guide

Other Libraries

Material Components
Material Components for Android (MDC-Android) help developers execute Material Design to build beautiful and functional Android apps.
Reference  User Guide
Android NDK
The Android NDK is a toolset that lets you implement parts of your app in native code, using languages such as C and C++.
Reference  User Guide
Android Game Development Kit libraries
The Android Game Development Kit C/C++ game libraries make it easier to build, debug, optimize, and maintain your games.
Overview 
Android Gradle Plugin
The Android Gradle Plugin (AGP) is the supported build system for Android applications and includes support for compiling many different types of sources and linking them together into an application that you can run on a physical Android device or an emulator.
Reference  User Guide
Cross device SDK
The Cross device SDK simplifies the development of rich and engaging multi-device experiences. Its core functionality includes device discovery and authorization, secure connections and data transfers, and multi-device sessions.
Reference  User Guide

Google Play

Play In-app Billing Library
Provides APIs to help you implement Google Play's in-app billing and subscription features.
Reference  User Guide
Play Core Library
Provides APIs to help you request, monitor, and manage on demand downloads for Play Feature Delivery, Play Asset Delivery, and offers additional APIs such as in-app updates and in-app reviews. This library is available in Java, Native code, Unity and Unreal Engine.
Play Install Referrer library
Provides APIs to securely retrieve referral content from Google Play.
Reference
Google Play Games Services Unity Plugin API (v2)
Provides the Google Play Games Services Unity Plugin API for developers. It is meant for developers who use the Unity Plugin (v2) implementation for their game.
Reference
Google Play Games Services Web REST API
Provides APIs for developers to enhance games with social leaderboards, achievements, game state, sign-in with Google, and more.
Reference
Google Play Games Services C++ API (v1)
Provides the Google Play Games Services C++ API for use with Google Play Game services. It is meant for developers who have an existing C++ implementation of their game.
Reference
Google Play Games Services Management API
Provides the Google Play Games Services Management API to issue REST calls to programmatically control the metadata underlying the Google Play Games Services features. This API simplifies your testing of Google Play games services features and gives you flexibility when managing your games to address cheating and fix player accounts.
Reference
Google Play Games Services Publishing API
Provides APIs that allows you to automate frequent tasks having to do with games production and distribution.
Reference

Google Assistant

Built-in Intents
Let users launch and control your Android app with their voice, using Google Assistant and App Actions.

Deprecated Libraries

These libraries are superseded by the AndroidX libraries and are no longer maintened. They are still shipped in the SDK to support legacy apps. For more information see the androidx migration guide.
Android Support Library
Provided a variety of Android feature and utility APIs that are compatible with a wide range of platform versions. The original library is superseded by the AndroidX libraries.
Android Test Support Library
Includes APIs for testing your Android app, including Espresso, JUnit Runner, JUnit4 rules, and UI Automator. The original library is superseded by the AndroidX Test library.
Architecture Components
Includes APIs for a variety of core app components, such as APIs that manage your UI component lifecycle, data persistence, view model, and more. The original library is superseded by the AndroidX libraries.
Constraint Layout Library
Legacy Support Library ConstraintLayout and related APIs for building constraint-based layouts. The original library is superseded by the AndroidX constraintlayout library.
Android Things Library
Provided APIs to build connected devices running the Android Things platform. The original library is no longer maintained.
Android Wearable Library
Provides APIs to build apps for wearable devices running Wear OS by Google. The original library is superseded by the AndroidX Wear libraries.