Compiled Libraries and Source Code

I have been contracted to design and deliver a data field. Cool. Actually make some Christmas money building some CIQ code.

I've developed a library of cool functions that make designing DFs quick and easy.

I'd like to deliver the source code as part of my contract, for the parts of the DF that are unique to their logic/features. But hide my utility functions in compiled form.

Is there a way to do this? A package that includes my compiled bits and their source code, so they could recompile the data field on their own after making some changes to their logic, which includes my compiled utility functions? Maybe a barrel, for example?

I have no idea... probably no possible.

Thanks!