send json file and save his server and return

I have this code

 <form class="new_estimate" id="new_estimate" action="/" accept-charset="UTF-8" method="post"><input name="utf8" type="hidden" value="&#x2713;" /><input type="hidden" name="authenticity_token" value="33mVvXpmjyFryaM6IlgRYl8Qx3YMCw9EQzmK4YBZ7TaSvwD/o/hAsOg5hdLLMAxOKMUAro+pgd288KJNUwHNQg==" />
<div class="field">
  <input placeholder="Enter your email address" class="form-control" type="text" name="estimate[email]" id="estimate_email" />
  <div class="checkbox">
    <input name="estimate[subscribe]" type="hidden" value="0" /><input type="checkbox" value="1" checked="checked" name="estimate[subscribe]" id="estimate_subscribe" />
    <label for="estimate_subscribe">
      Receive useful information about building apps in your inbox. No spam. Ever.
    </label>
  </div>
</div>
<textarea hidden="hidden" ng-bind="featureList | json" name="estimate[feature_list]" id="estimate_feature_list">
</textarea>
  <div class="actions">
  <input type="submit" name="commit" value="Save Estimate" class="btn btn-
  success btn-lg" data-disable-with="Save Estimate" />
  </div>
     </form></div>
   <![CDATA[window.gon={}; gon.estimateId={};]]>

How me save json file in server and return him link with user_id?(in link use estimateId) For example link to list http://ift.tt/2uodFr2 and save list http://example.com/ + gon.estimateId +/list