title: TypeError: Converting circular structure to JSON in nodejs
body: <p>I am using request package for node.js</p>
  <p><strong>Code :</strong></p>
  <pre><code> var formData = ({first_name:firstname,last_name:lastname,user_name:username, email:email,password:password});
  
    request.post({url:'http://localhost:8081/register', JSON: formData}, function(err, connection, body) {
  
  exports.Register = function(req, res) {
      res.header(&quot;Access-Control-Allow-Origin&quot;, &quot;*&quot;);
      console.log(&quot;Request data &quot; +JSON.stringify(req));
  </code></pre>
  <p>Here I am getting this error :</p>
  <blockquote>
  <p>TypeError: Converting circular structure to JSON</p>
  </blockquote>
  <p>Can anybody tell me what is the problem</p>