title: Getting last added item in Firebase using REST API
body: <p>how can I get the last added item in Firebase using rest api? I understand that firebase support filter as stated here 
  <code>https://firebase.google.com/docs/database/rest/retrieve-data#section-rest-filtering</code> but I cannot find how to do it.</p>
  
  <p>When I access the api endpoint <code>https://&lt;firebaseproject&gt;.firebaseio.com/messages.json?shallow=true</code> I got this data:</p>
  
  <pre><code>{
    "-KgclTDbCWnm5pxV7efg" : true,
    "-KgclglfW7bxGSeX6rlg" : true,
    "-Kgclo4-fQzWu095vELL" : true,
    "-Kgcm-R-GTJR670Co9kl" : true
  }
  </code></pre>