I am currenty trying to write my first ever stack exchange application and was using the SE Jaavascript SDK v 2.0 for this purpose. I am stuck on the point of authenticating the user. I followed the steps mentioned [here][1] I am able to complete the call to SE.init successfully, However, when I call SE.authenticate, I get a login window where-in I login using my StackExchange account. At this point, I get an error that says **Unexpected domain on proxy URL**. I would like to point out that I am using a cloud-based IDE at nitrous.io and hence I can test-run this application within the preview URL provided by them. In my case, I access the preview URL as follows : > http://cybertron-nodejs-11139.apse1.actionbox.io:3000/files/index.html Here is my code snippet for the JS file that contains all the initialization and authentication logic: $(document).ready(function() { SE.init({clientId: 1880, key: '396D79cbzmt3w*Pf)E7AUw((', // Used for cross domain communication, it will be validated channelUrl: 'http://cybertron-nodejs-11139.apse1.actionbox.io:3000/files/blank.html', // Called when all initialization is finished complete: function(data) { console.log(data) $('#login-button') .removeAttr('disabled') .text('Run Example With Version '+data.version); } }); $("#login-button").click(function() { SE.authenticate({ success: function(data) { alert( 'User Authorized with account id = ' + data.networkUsers[0].account_id + ', got access token = ' + data.accessToken ); }, error: function(data) { alert('An error occurred:\n' + data.errorName + '\n' + data.errorMessage); }, networkUsers: true }); }); [1]: http://api.stackexchange.com/docs/js-lib