Is there any configuration code that I have to add in the application Bootstrapper to enable FluentValidation in Nancy?
Following the example from https://github.com
Are you using one of the Bootstrapper packages (autofac, ninject, unity, windsor, structuremap)? If you are then you need to inherit from the bootstrapper type, override ConfigureApplicationContainer and register the type in the container. If you are using the default bootstrapper then it should wire itself up
With out next release, 0.12, it will wired up automatically no matter what bootstrapper you are using