Example implement for heroku info APP_NAME. Requires rest-client and nokogiri.

heroku-api-client-example.rb

require 'rest_client'
require 'nokogiri'

resource = RestClient::Resource.new('https://api.heroku.com', 'USERNAME', 'PASSWORD')
args = [:get, nil, {
          'X-Heroku-API-Version' => '2',
          'User-Agent'           => 'my heroku client/1.0',
          'X-Ruby-Version'       => RUBY_VERSION,
          'X-Ruby-Platform'      => RUBY_PLATFORM
        }].compact
doc = Nokogiri::XML(resource['apps/APP_NAME'].send(*args))
puts doc