Interesting @reagent -- so something like this?

```ruby
def method_missing(method, *args, &block)
  if respond_to?(method)
    main_app.send(method, *args)
  else
    super
  end
end

def respond_to?(symbol, include_all=false)
  super &&
    %w(_path _url).any?{ |ending| method.to_s.end_with?(ending) } &&
    main_app.respond_to?(method)
end
```