title: How to handle API callbacks in ASP.NET MVC (Helloworks API in my case)
body: <p>As per their documentation from link <a href="https://docs.helloworks.com/v3/reference#callbacks" rel="nofollow noreferrer">https://docs.helloworks.com/v3/reference#callbacks</a></p>
  
  <p>"With the HelloWorks API you can use callbacks to be notified about certain events. Currently we support a callback to be registered when a step is started, the cancellation of a workflow, and the completion of a workflow.</p>
  
  <p>The callback URL will be called according to the following:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>curl -X POST https://your.domain.com/some/path
       -H "X-HelloWorks-Signature: {signature}"
       -H "Content-Type: application/json"
       -d "{payload}</code></pre>
  </div>
  </div>
  </p>
  
  <p>I am not able to figure out how can I handle the callback in ASP.NET MVC 4.0. The callback returns data on JSON format. Once I receive the data, I can format it as per my need and can save to database. But how can I get the data in my controller? Guidance from experts on APIs are highly appreciated. Thanks in advance.</p>