title: xAuth on OAuth2 client_id vs client_key?
body: <p>I'm familiar with OAuth 1.0 and xAuth flow for twitter API. Now I'm implementing OAuth 2.0 and xAuth flow on my own product (web and native mobile app). Reading upon the xAuth flow on twitter api docs, it says that I should include <code>consumer_key</code> and <code>consumer_secret</code> (that are given once developer registers the app with twitter) when requesting for authorization token. xAuth skips this step and goes directly for <code>access_token</code> request.</p>
  
  <p>In OAuth 2.0 there is no such thing as <code>client_key</code> which should be sent to <code>authorize</code> endpoint. Instead you have to provide <code>client_id</code>. Can anyone confirm that it's analogy to <code>client_key</code> in OAuth 1.0? If so - should I send the <code>client_id</code> and <code>client_secret</code> along with <code>oauth_*</code> and <code>x_auth*</code> parameters to <code>access_token</code> endpoint? Maybe I'm completely misunderstanding something here? Any explanation is much appreciated!</p>