title: accessing facebook private messages using access token using Facebook API
body: <p>We have angularJs &amp; C# web aplication.
  We are planning to use our facebook page to handle our customer issues and complaints.
  We will show facebook visitor posts in our website so our representative notice it and reply on same. (may be new comment or reply existing)</p>
  
  <p>Our representative ask customer to send private message and then user initiate message to us and then we can see that message in our website and reply to that message through our website.
  By this way we will able to sort out problems of our customer through our application.</p>
  
  <pre><code>public static FacebookClient GetClientApplicationAccessToken(FacebookClient client)
  {
      dynamic accessToken = client.Get("oauth/access_token", new
      {
          client_id = "my_ApplicationId",
          client_secret = "my_AppSecretKey",
          grant_type = "client_credentials"
      });
      client.AccessToken = accessToken.access_token;
      return client;
  }
  
  
  public static dynamic GetFacebookPosts(string pageId)
  {
      var client = new FacebookClient();
      GetClientApplicationAccessToken(client);
      dynamic postObject = client.Get("/" + pageId + "/feed?fields=message,from,created_time,full_picture");
      dynamic postJson = JsonConvert.DeserializeObject(posts);
      return postJson;
  }
  </code></pre>
  
  <p>By this access token we are able to fetch Facebook post, but not possible when we try to fetch conversation between Our Facebook page &amp; our customers through private messages.</p>
  
  <pre><code>dynamic postdaObject = newclient.Get("me?fields=conversations{messages{created_time,message}}");
  </code></pre>
  
  <p>I think when we use access token from above method i.e.GetClientApplicationAccessToken() it is not working. but if I replace hard coded user access token then it's working. As our application end user will see Facebook messages and will reply to them, it does not require FaceBook Login button. We need some permanent access token by which we can fetch private messages from Facebook without any login button. Kindly help me to solve this issue. </p>