While at this point there's no official C++ API provided you might try accessing C++ object interfaces directly (it's a lot of coding though). We plan to release an SDK for implementing your own C++ extensions within next couple of months. As of now we don't have any plans for supporting C# - but we have a prototype version for JavaScript. Interestingly JavaScript and Python objects will be fully interoperable so dbzero might become a convenience interface between those worlds.