title: Web API 2 RegisterExternal Account with existing access token
body: <p>Using the Facebook iOS SDK I have received an access_token for the user of my iOS application which allows me to view their basic profile information. I would like to use that token to register &amp; login users against my existing web application. </p>
  
  <p>I don't want the user to navigate to the <code>account/ExternalLogins</code> URL and be redirected from there in a WebView as at this point I already have the access token that provides. What I don't understand is how I can make use of the <code>Acccount/RegisterExternal</code> or <code>Account/AddExternalLogin</code> methods and provide them with this existing token and a username/email to register a new user. All of my attempts have been met with <code>400</code> or <code>500</code> errors. </p>
  
  <p>I've checked a lot of stack overflow answers and blog posts but they seem to roll-your-own or modify existing methods in the <code>AccountController</code>. But I don't see why doing either of these things are necessary when it looks like everything is already there for you. I'm just not sure how I can make use of it! </p>
  
  <p>Any help would be greatly appreciated. </p>
  
  <p><strong>Edit:</strong> 
  I ended up using <a href="http://codetrixstudio.com/mvc-web-api-facebook-sdk/" rel="noreferrer">this custom solution by codetrix</a>. It's not what I originally wanted but it was simple to include and works so far. If anyone is able to answer the original question then please do. </p>