title: System.IdentityModel.Tokens.JwtSecurityToken custom properties
body: <p>My AuthServer is currently using the following code to generate a JwtSecurityToken:</p>
  
  <pre><code>var token = new JwtSecurityToken(_issuer, audienceId, data.Identity.Claims, issued.Value.UtcDateTime, expires.Value.UtcDateTime, signingKey);
  var handler = new JwtSecurityTokenHandler();
  var jwt = handler.WriteToken(token);
  </code></pre>
  
  <p>The payload looks like this:</p>
  
  <pre><code>{
    "unique_name": "myUserName",
    "sub": "myUserName",
    "role": "API_User",
    "iss": "Automation",
    "aud": "099153c2625149bc8ecb3e85e03f0022",
    "exp": 1486056731,
    "nbf": 1483464731
  }
  </code></pre>
  
  <p>I would like to add some custom fields/properties within the token payload, such as ProfilePicURL, so that the payload can look something like this:</p>
  
  <pre><code>{
    "unique_name": "myUserName",
    "sub": "myUserName",
    "role": "API_User",
    "iss": "Automation",
    "aud": "099153c2625149bc8ecb3e85e03f0022",
    "exp": 1486056731,
    "nbf": 1483464731,
    "profilePicture": "http://url/user.jpg"
  }
  </code></pre>
  
  <p>How do I go about adding these custom properties and ensuring that the token contains them?</p>