Oneofs, at least with gogoproto, are quite unpleasant to work with. There's a separate intermediate type generated for each member of a oneof field. With the fo

Oneofs, at least with gogoproto, are quite unpleasant to work with. There's a separate intermediate type generated for each member of a oneof field. With the following message: message Foo { oneof bar { Baz baz = 1; Qux qux = 2; } } You'll have the types Foo, Baz and Qux like you'd expect, but you also get Foo_Baz, which does nothing but wrap the Baz for use with the Foo.bar property, and Foo_Qux, which does the same thing but for Qux instead of Baz. To make matters worse, the types all implement an interface which is declared but not exported. Stringing the whole thing together to assign to a oneof looks like this: foo := &rpc.Foo{Bar: &rpc.Foo_Baz{Baz: &rpc.Baz{}}} That example makes it look better than it really is; in practice, you'll probably have more properties and longer names.