:/ it is not as easy as I though , I added spree.*, but it didn't work when the engine is not mounted on root, the helper seems to be working, it creates the route with the namespace, but when I go to that route I got a 404 error , the problem is with devise and how they handle the omniauth path_prefix config, this config is set by devise to always point to /users/auth/:provider, you can see what I'm talking about in [this method](https://github.com/plataformatec/devise/blob/master/lib/devise/rails/routes.rb#L386-L406) from the devise source