Is there any plan to separate C++ lib

[hombit]

So there is the question. Do you have any plan to create a C++ library which could be used without Python bindings?

[dfm]

I don't have any plans for that. It's possible that you could find your way around the C++ source which lives here:

https://github.com/dfm/george/tree/main/src/george/include/george

but it wasn't designed for public consumption really. If you're interested in the fast HODLR solver, a better pure-C++ interface lives at:

https://hodlrlib.readthedocs.io/en/latest/