title: CORS header ‘Access-Control-Allow-Origin’ missing in servant
body: <p>using the <code>run</code> from <code>Network.Wai.Handler.Warp</code> function to server rest api</p>
  
  <pre><code>run :: Port -&gt; Application -&gt; IO ()
  </code></pre>
  
  <p>but while doing <code>post</code> request, getting an error <code>CORS header ‘Access-Control-Allow-Origin’</code>.
  any idea how to overcome this in servant/haskell</p>