How to get the count of Users Unread Posts

Hi,

According to your post, my understanding is that you want to get the unread or not viewed post by a user.

There is no directly way to get the unread or viewed post, however, we can get the feed of microblog posts that mention the current user using Social API as below.

http:////_api/social.feed/my/mentionfeed/clearunreadmentioncount

Or gets the count of unread mentions for the current user:

http:////_api/social.feed/my/unreadmentioncount

For more details, you can refer to the article below.

http://msdn.microsoft.com/en-us/library/office/dn155789(v=office.15).aspx#bk_myMentionFeedClearUnreadMentionCount