title: How to identify whether http request is from browser or from proxy server (or server)?
body: <p>I have a server that takes http request and return json data. How does my server know if the http request is from a client browser and not from a server?  especially if traffic may proxy from a client to another server and make a call to my server.</p>
  
  <p>I know i can check the http header to know user-agent, remote-addr..etc but it is not secure.  People can fake the http request header.  </p>
  
  <p>What other tricks I can do to identify the incoming request?</p>