Creating streaming variants of the Kratos middleware allows us to use the functionality with all endpoints right away, and we're making a technical bet that any unified middleware interface Kratos adopts will be similar to a streaming interface or they will adopt a dual interface similar to grpc itself. Either way, these implementations hopefully will be able to be contributed with minimal modification once streaming middleware is supported upstream.

Reference implementation (validation): https://github.com/project-kessel/relations-api/pull/116/files - compare to original Kratos implementation: https://github.com/go-kratos/kratos/blob/main/middleware/validate/validate.go