Sinatra Example

    begin
      require 'sinatra'
      require 'omniauth'
      require 'openid/store/filesystem'
      require 'omniauth-twitter'

    rescue LoadError
      require 'rubygems'
      require 'sinatra'
      require 'omniauth'
      require 'openid/store/filesystem'
      require 'omniauth-twitter'
    end
    
    use Rack::Session::Cookie
    use OmniAuth::Builder do
      provider :open_id, OpenID::Store::Filesystem.new('/tmp')
      provider :twitter, 'consumerkey', 'consumersecret'
    end

    get '/' do
      <<-HTML
      <a href='/auth/twitter'>Sign in with Twitter</a>
      
      <form action='/auth/open_id' method='post'>
        <input type='text' name='identifier'/>
        <input type='submit' value='Sign in with OpenID'/>
      </form>
      HTML
    end
    
    post '/auth/:name/callback' do
      auth = request.env['omniauth.auth']
      # do whatever you want with the information!
    end