[cle]

I agree, I love protobuf and JSONSchema and Thrift, I think they're great ideas that solve important problems.

But the hype is getting carried away--they aren't a silver bullet for distributed systems, they're just a way to manage schema. Define a schema in an IDL, and Protobuf/Thrift/whatever generate schema validators and serializer/deserializers for clients and servers. But they are not type safe across systems, and that they compile doesn't imply anything about whether they will actually work at runtime.

[stickfigure]

Sure, and gRPC doesn't guarantee that the server is turned on when the client makes a request. Some expectations are unreasonable.

On the other hand, if you publish one set of proto files and all clients & servers consume these artifacts, the system as a whole is more "typesafe" and reliable than if you just post swagger docs and expect all your developers to check them daily for updates.

gRPC means API changes stand a good chance of getting caught by build systems. That seems about as reasonable a definition of "type safe across systems" as can be expected.

[cle]

I agree completely which is why I love proto.

[computerex]

Couldn't have put it better myself.