How to get Android O sdk in Android Studio

Android O introduces several new features and APIs, and includes changes that can affect the behavior of your app even if you change nothing.

1. Install Android Studio 2.4 Canary. Only Android Studio 2.4 includes support for all the new developer features available with Android O. So you need to get the canary version of Android Studio 2.4 to begin using the Android O SDK. But you can still keep your stable version of Android Studio installed.
   
2. Launch Android Studio 2.4 and open the SDK Manager by clicking Tools > Android > SDK Manager.
3. In the SDK Platforms tab, check Show Package Details. Below Android O Preview check the following:
   • Android SDK Platform O
   • Google APIs Intel x86 Atom System Image (only required for the emulator)
4. Switch to the SDK Tools tab and check all items that have updates available (click each checkbox that shows a dash ). This should include the following that are required:
   • Android SDK Build-Tools 26.0.0 (rc1 or higher)
   • Android SDK Platform-Tools 26.0.0 (rc1 or higher)
   • Android Emulator 26.0.0
   • Support Repository
5. Click OK to install all the selected SDK packages.

Now you're ready to starting developing with the Android O Developer Preview.

Update your build configuration

Update compileSdkVersion, buildToolsVersion, targetSdkVersion, and the Support Library version with the following versions:

android {
  compileSdkVersion 'android-O'
  buildToolsVersion '26.0.0-rc1'

  defaultConfig {
    targetSdkVersion 'O'
  }
  ...
}

dependencies {
  compile 'com.android.support:appcompat-v7:26.0.0-alpha1'
}

You cannot publish your app with this configuration. The "O" version is a provisional API level that is usable only for development and testing during the Android O Developer Preview. You must wait to publish your Android O changes until the final API level is released, and then update your configuration again at that time.

More about Android O: https://developer.android.com/index.html