Does flatbuffers have an RPC mechanism? Or is it purely a serialisation tool? Cap'n Proto is both. I.e. you have the serialisation, which can be used on its

Does flatbuffers have an RPC mechanism? Or is it purely a serialisation tool? Cap'n Proto is both. I.e. you have the serialisation, which can be used on its own, but you can also define interfaces with methods that can pass those serialised structs as parameters, and which return asynchronous promises.