rails_sinatra.rb

# http://robots.thoughtbot.com/how-to-share-a-session-between-sinatra-and-rails
# wanna do this
get '/dashboard' do
  if session[:user_id].present?
    redirect to('/')
  else
    # set up and render dashboard
  end
end

# then
# Rack::Builder

# config.ru
map '/api' do
  run MySinatraApp.new
end

map '/' do
  run MyRailsApp::Application.new
end

#or we can load sinatra apps with in rails
MyRailsApp::Application.routes.draw do
  mount MySinatraApp.new => '/api'
end