Let's assume I created a rails app passing the --api flag.
I want one or two routes that are full rails, with extra middleware, that inherit from ActionController::Base to serve the javascript single page application or whatever, etc.
I can presumably put them into a Rails engine and have the rest of the app use the api controllers and less middleware.
What would I need to do to configure a Rails Engine to handle the root route like a full rails app while the main app was api only? Are there alternative configurations that may be worth considering?