Is it possible to validate (using FluentValidation) a request sent via the service gateway (Gateway.Send)? If not, what is the logic behind the design decision?
Fluent Validation is executed in a Request Filter that writes the error directly to the Response Stream and closes it, whereas internally a gateway executes a service directly (i.e. by passing the Request Filters).
How would I go about validating a request sent via the service gateway?
You can always substitute the Service Gateway with your own, but I’ve just added support for Service Gateway Request/Response filters + we’re now validating Request DTO’s by default in this commit.
This change is available from v4.0.61 that’s now available on MyGet.