Ah, it’s been a while since I wrote this, so please correct me if I’ve missed anything—my approach remains to use C# and GRPC in a way that serves both GRPC and GraphQL.

My understanding of field *Masks* is that they are an operation performed by GRPC as a way to scrub/shrink the amount of data being returned in the pipe (post-query). Contrast this against a **Selection** which actually informs the compilation of the SQL queries (I’m describing an entire execution engine, here).

That aside, field masks are merely field selections. This is a small subset of GQL. In the current form of the library I have built for my C# data communication, I leverage other aspects of the Selection-based GQL-style syntax… like nested RPCs, aliasing, directives, etc.