Posted by David Brazdil and Nicolas Geoffray, Software Engineers

In Android, we care immensely about providing the best experience to our users and our developers. With each OS release, new features enable you to provide amazing experiences for users; however, we noticed that some app developers have been using non-SDK interfaces, which leads to increased crashes for users and emergency rollouts for developers. We want to do better and need your help to ensure that Android is stable with each new OS.

Three months ago, we announced our plans to start restricting the usage of non-SDK interfaces in Android P. We know these restrictions can impact your release workflow, and we want to make sure you have the tools to detect usage of non-SDK interfaces, as well as time in your planning for adjusting to the new policies and for giving us feedback.

In the Developer Preview and Beta 1, we have provided ways for you to see the impact of these restrictions on your app. In the Developer Preview, use of restricted APIs show up in logs and toast messages, and in Beta 1, we provided a StrictMode policy that allows you to programmatically find these restrictions and do your own logging. For example:

We understand there can be multiple reasons apps want to use non-SDK interfaces, and ensuring your app will continue to work in Android P is important to us. Many of you have explained your use cases through our issue tracker (thank you!), and for most of these requests, we have lifted the restrictions on specific non-SDK interfaces for Android P by adding them to the greylist. In addition, our team has conducted static analysis on millions of apps and processed thousands of automated reports from internal and external beta testers. Through this analysis, we have identified additional non-SDK interfaces that apps rely on and added them to the greylist. For everything on the greylist, we will be investigating public SDK alternatives for future releases. However, it's possible we may have missed some non-SDK interface uses, so we have made the majority of them available for apps whose target SDK is Android Oreo or below.

In summary, apps running on Android P will be subject to restricted usage of non-SDK interfaces. If you are targeting Android P, the greylist shows the non-SDK interfaces that will still be available, while all other non-SDK interfaces will not be accessible. If you are targeting Android Oreo or below, most restrictions will not apply, but you will get logcat warnings if you are accessing non-SDK interfaces that are not in the greylist (note that users don't see such warnings).

Try out our new Beta 2 release and use StrictMode to detect your non-SDK interfaces usage. You should expect Beta 2 to closely match what the final release will implement for restricting non-SDK interface usages. Also, please take a look at our new FAQ, which we hope will answer any questions you have around the feature. If not, let us know!