example1.rb

Create = Dry::Validation.Form do
  key(:organization_id).required
  key(:code).required

  rule(:unique_code_organization) do
    !Code.exists?(code: value(:code), organization_id: value(:organization_id))
  end
  
  configure do
    option :market_repo, WheelsApp.instance["repositories.market"]
  end
end

example2.rb

Create = Dry::Validation.Form do
  key(:organization_id).required
  key(:code).required(:uniq?)

  rule(:unique_code_organization) do
    !Code.exists?(code: value(:code), organization_id: value(:organization_id))
  end
  
  configure do
    option :market_repo, WheelsApp.instance["repositories.market"]
    
    def uniq?(code)
      !Code.exists?(code: code, organization_id: value(:organization_id))      
    end
  end
end