[hardwaresofton]

AFAIK there is not a standardized way to do this but there's no reason it can't -- you are free to define your own Content-Type or use framed binary, or whatever else. If you already have schemas on either side (or code to do dynamic discovery), and a way to pack/unpack you can send different kinds of data across.

This is less ideal than GraphQL in this case, since GraphQL has done this hard work and standardized it/created the conforming reference clients/servers already.