Adding Verification only to rails app with Authy, Twillio and Devise

Im building out a dispatch app with Rails 5, Ruby 2.4.0 and want to incorporate Twillio for SMS Authy (only for phone verification) and Devise for user authentication.

My question is following the Twillio tutorial Twillio Authy verification tutroial Do I want to create a custom devise registrations controller for this workflow or is it better to create a custom user controller to handle this?

As my app sits now an "owner" a class of User is created through a nested form on the account create action. Im just not sure that if I will hit the user controller on a create user through my account controller..?

This my be a garbage question, but im really lost here not sure how to proceed.

Baking the SMS verification into the standard Devise flow seems like an excellent idea instead of duplicating the functionality. Fortunately its pretty easy:

class TwillioRegistrationsController < Devise::RegistrationsController

  def create
    super do |user|
      authy = Authy::API.register_user(
        email: user.email,
        cellphone: user.phone_number,
        country_code: user.country_code
      )
      user.update(authy_id: authy.id)
    end
  end

  protected

  def after_sign_up_path_for(resource)
    "users/verify"
  end
end

Devise lets you "tap" into the flow of almost all the controller methods by yielding. Devise::RegistrationsController#create yields the resource after it has been saved which is the perfect place to put the twillio logic.

You then need to permit the additional parameters in devise and customize the form with additional fields.

class ApplicationController < ActionController::Base
  def configure_permitted_parameters
     devise_parameter_sanitizer.permit(:sign_up, keys: [:phone_number, :country_code])
  end
end

Note that you still need to setup a controller to handle verifications, but you can do that by following the tutorial.