as someone who works with interfaces and not variants i don't like any protocol that doesn't have static typing and i honestly don't see the point of complex rpc specification compilers when it's just a friggin function call about 10% of cases, partial failures can happen that should really return an error and a partial value (eg, a result being an array of fields from an array of inputs) but nope, can't do that with typical C++/Rust error handling idiom this forces you to design APIs as single shot rather than batched which is a pretty rigid and performance limiting way to do things, especially when it is easy to aggregate queries to be handled by for example databases with concurrent queuing (especially distributed ones where the processing can be fanned out to multiple servers) i say, if you make the client and build out a relay interface go ahead, make your hipster CBOR encoder API but for the love of God do not make up your own fancy new RPC API if you do not intend to support a sufficient range of common language bindings, NATIVELY... just take the json and binary encode it, don't fuck around