The Codename One Open Source API is a vast abstraction of mobile device platforms providing rich portable functionality. It leverages the highest feature set within devices (nicknamed: highest common denominator) to provide functionality smartphone owners are accustomed to.

The API is mature and operator tested on a global scale, yet it is still rapidly evolving to meet the changing demands of the global market.
You can browse the javadoc API here,
to get a sense of its depth and breadth.

The API includes tremendous amount of functionality including rich and infinitely customizable UI components, as well as all device features from calls to camera, GPS etc.

No API can cover all the bases all the time, which is why we provide native interfaces that allow you to embed any arbitrary operating system component or code right in the middle of any Codename One application. You can write native code in the platform specific language (Dalvik-Java for Android, Objective C for iOS etc.) and use that code to create a platform specific widget that can be embedded right into the Codename One component hierarchy without interfering with application flow.