title: asp net web api Authentication token expiration?
body: <p>I am client of an asp net web API application which uses token based authentication. The token structure is as follows:</p>
  
  <pre><code>{
      access_token: "…",
      token_type: "bearer",
      expires_in: 3599
  }
  </code></pre>
  
  <p>obviously it is set to expire, and I am currently asking for a new token with every request, which i believe not to be a good practice since every API request is actually 2, one for authentication and another for the actual request. So am trying to implement some caching of the token, but i do not know what exactly the <code>expires_in</code> field means, is it seconds, miliseconds?</p>