API level validations with Grape

api_level_validations_with_grape.rb

require 'grape'

module Blog 
  class Web < Grape::API
    
    ...
    
    desc "Create post comment"
    params do
      requires :id, type: Integer
      requires :comment, type: Hash do
        requires :text, type: String
      end
    end
    post '/api/v0/posts/:id/comments/' do
      context = UseCases::Comments::Create::Base.perform(params)

      status 409 if context.status.conflict?
      status 201 if context.status.created?

      context.data
    end
    
    ...
    
  end
end