controller.rb

op = ::Admin::Client::Create.(params)
 render_client(op.profile)

incoming_contract.rb

class Admin::IncomingContact::Create < BaseOperation
  attr_reader :client, :car, :case

  CarContract = Class.new(Admin::Car::Create.contract) do
    property :client_id, readable: false

    validation :validate_client, inherit: true do
      optional(:client_id).maybe(:int?)
    end
  end

  contract do
    property :client, form: Admin::Client::Create.contract
    property :car,    form: CarContract
    property :case,   form: Admin::Case::Create.contract

    validation do
      required(:client).filled
      required(:car).filled
      required(:case).filled
    end
  end

  def setup_model!(params = {})
    @client = UserFabric.build_client
    @car = ::Car.new(client: @client)
    @case = ::Case.new(car: @car)

    self.model = OpenStruct.new(car: @car, case: @case, client: { user: @client.user, profile: @client })
  end

  def process_without_exception(params)
    validate(params)
    contract.save
  end

end

op.rb

class Admin::Client::Create < BaseOperation
  attr_reader :profile

  contract do
    include Reform::Form::Composition

    properties :name, :surname, :zc_comment, on: :profile do
      validation do
        required(:name).filled(:str?)
        required(:surname).filled(:str?)
        optional(:zc_comment).maybe(:str?)
      end
    end
    properties :phone, :email, on: :user do
      required(:phone).filled(:str?)
      optional(:email).maybe(:str?)
    end
  end

  def process_without_exception(params)
    @profile = Profile::Client.new
    @profile.user = User.new

    validate(params, user: @profile.user, profile: @profile)
    contract.save
  end

end