You can expand the capability of the Liberty profile by using product extensions. You can write your own Liberty features and install them onto an existing Liberty profile server, or you can package them for delivery to your users.
This section describes how to develop features for a product extension, how to install features to the built-in "usr" product extension, and how to use your features in an application server. The Liberty profile provides various System Programming Interfaces (SPIs) that you can use to extend the runtime environment; you can also use more advanced features such as operating the Liberty profile server from your Java™ applications programmatically.
The Java API documentation for each Liberty profile SPI is detailed in the Programming Interfaces (APIs) section of the information center, and is also available as a separate .zip file in one of the javadoc subdirectories of the ${wlp.install.dir}/dev directory.
For an overview of writing product extensions for the Liberty profile, see Liberty profile: Product extension.
For full details of how to extend the Liberty profile, see the following subtopics: