I really enjoy the fluent validation feature of ServiceStack, it keeps my service code clean and readable. However like explained and questioned in these posts: Override http status code from validator and ServiceStack - Validation and Database Access there is a big difference between validation and verification.
The suggested way to work with verification in the above posts is to make use of request filters, but that doesn't seem nearly as clean as writing business logic using a fluent syntax.
Is there by any chance any work to get a Fluent Verification feature? Or if not, any suggestions of how I should build one? Or a deeper explanation why I should not build one?
I like the idea of separating the validation (ensuring correct format), verification (ensuring business rule appliance) and the service code and at the same time providing my users with sensible and good http status codes.
The Validators are also injected with any dependencies so you could also use them in the FluentValidation lambdas similar to the AddressValidator example in the docs.
Don't see any benefit to add anything different, you can do simple typed validation using FluentValidation, more complex validation inside Service impl or add custom logic in Request Filters which you can genericize by having Request DTO's implement a shared interface.