grape api example

cities_api.rb

# app/controllers/api/v1/cities_api.rb

class Api::V1::CitiesAPI < Api::V1::BaseAPI
  resource :cities do
    params do
      optional :term, :type => String
    end

    get '/' do
      cities = ::City.ordered_by_name_asc
      cities = cities.unscoped.by_name(params[:term]) if params[:term].present?

      present :cities, cities, :with => ::Api::V1::CityEntity
    end
  end
end