Solidus (Spree) render API serializers outside the API

products_controller.rb

# app/controllers/products_controller.rb
class ProductsController < Spree::ProductsController

  helper Spree::Api::ApiHelpers

  def index
    @searcher = build_searcher(params.merge(include_images: true))
    @products = @searcher.retrieve_products

    json = Rabl.render(nil, 'spree/api/products/index.v1',  {
        format: :json,
        locals: => {
            products:  @products,
        },
        :scope  => view_context  
      }
    )
    
    render json 
  end
end

rabl_init.rb

# config/initializers/rabl_init.rb
require 'rabl'
Rabl.configure do |config|
  # hack to be able to use json serializers defined in the solidus api outside solidus api
  solidus_api_gem = Bundler.load.specs.find{|s| s.name == "solidus_api" }
  config.view_paths += [ solidus_api_gem.full_gem_path + "/app/views/"]
end

please note the code the API serializers have not really been conceived to be used outside the API.
Serializers rely A LOT on helpers available in the API controllers and views which makes it VERY difficult to use outside the API.
I finally decided to write my own serializers.