[smallnamespace]

Sure, if you can guarantee that your app will always be in that environment.

Otherwise, you run the risk of having to redo all your protos (+ downtime) if/when your app needs to scale up. I'm not sure whether that's worth avoiding some proto validation logic in the client code.

From https://developers.google.com/protocol-buffers/docs/proto#si...:

> Required Is Forever

> You should be very careful about marking fields as `required`. If at some point you wish to stop writing or sending a required field, it will be problematic to change the field to an optional field – old readers will consider messages without this field to be incomplete and may reject or drop them unintentionally. You should consider writing application-specific custom validation routines for your buffers instead. Some engineers at Google have come to the conclusion that using `required` does more harm than good; they prefer to use only `optional` and `repeated`. However, this view is not universal.