xApps can be written in variety of programming languages. The current example xApps are written in C++ and go.

An xApp interacts with the other xApps and the RIC platform components using two primary mechanisms:

• RMR (RIC Message Router) messaging layer that provides methods for sending an receiving messages and populating and reading fields in those messages
  • Documentation: RIC Message Router (RMR)
  • Repo (C/Python): git clone "https://gerrit.o-ran-sc.org/r/ric-plt/lib/rmr"
• SDL (shared data layer) abstraction layer which provides methods for reading and writing data in a shared persistent key-value store in the RIC
  • Repo (go): git clone "https://gerrit.o-ran-sc.org/r/ric-plt/sdlgo"
  • Repo (Python):
  • Repo (C++):
  • Library for accessing R-NIB (network topology information - go): git clone "https://gerrit.o-ran-sc.org/r/ric-plt/nodeb-rnib"
  • Library for accessing UE-NIB (UE related information - go): git clone "https://gerrit.o-ran-sc.org/r/ric-plt/ue-nib

Please see  Supporting A1 policies for details on how your xapp should interact with A1 to receive policy guidance.