title: How to allow cross site origin requests in Google App Engine?
body: <p>I have a simple API made with Express that is returning json. The Express server is running on Google App Engine. I'm using cors (<a href="https://www.npmjs.com/package/cors" rel="nofollow noreferrer">https://www.npmjs.com/package/cors</a>) to enable ALL CORS-requests, but I still get "No 'Access-Control-Allow-Origin' header is present on the requested resource." when doing AJAX requests from a SPA application.</p>
  
  <p><code>app.use(cors())</code> </p>
  
  <p>Default settings for above according to the documentation is: 
  <code>
  { "origin": "*", 
  "methods": "GET,HEAD,PUT,PATCH,POST,DELETE", 
  "preflightContinue": false, 
  "optionsSuccessStatus": 204 
  }
  </code></p>
  
  <p>That should be enough since I'm only doing a simple GET-request from my SPA.</p>
  
  <p>Any ideas?</p>