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.