xApp SDK
xApp SDK is build to be simple but also flexible so as to facilitate the xApp development to meet the user's needs.
Thanks to SWIG, xApps could be developed in multiple languages, including C, C++, Python and Golang. The core of the xApp development is a set of signatures/functions provided by the C SDK, which utilize the available service models. This signatures set the baseline by managing the complete xApp lifecycle and signaling presenting on the previous page. They also create fertile ground for further development of xApp letting space for innovation and creativity.
Figure 1 presents the structure of the xApp SDK. As we can see, the core is the C SDK which includes the main signatures in C that enable the xApp development. On top of it, a C++ wrapper is designed to wrap these signatures creating another layer of abstraction with a new set of signatures that are a bit simpler but almost the same since they utilize the C SDK internally. This way, support for C++ language is enabled. Then we wrap everything with SWIG library allowing the xApp Development in other languages, including Python and Go.