app.rb

# Bits and pieces from my large, multi-file Sinatra app.. just to show structure

# -----

# Main base Sinatra app setup
module Cio
  class App < Sinatra::Base     
    configure do      
      # Set global vars
      set :root, APP_ROOT
      set :environment, ENV['environment'] || environment
      set :secret, ENV['secret']
      
      # Connect to database
      MongoMapper.connection = Mongo::Connection.new(hostname)
      MongoMapper.database = "#{dbname}-#{environment}"
    end    
  end
end

# Load plugins, models, controllers, and helpers
(Dir[APP_ROOT + "/plugins/*.rb"] + Dir[APP_ROOT + "/app/models/*.rb"] + Dir[APP_ROOT + "/app/controllers/*.rb"]).each { |f| require f; puts f }

# Attach helpers and register plugins
module Cio
  class App
    helpers Cio::Helpers
    register Sinatra::SessionAuth
  end
end

example_api_controller.rb

# Root level and "controller-less" methods and webapp actions

module Cio
  class App
    API_PREFIX = "/api/v1"

    get "#{API_PREFIX}/users/?" do
      [..]
    end

    post "#{API_PREFIX}/users/:id" do
      [..]
    end
  end
end

helpers.rb

module Cio
  module Helpers
    [..]
  end
end