ECONNREFUSED when making GET request in app, but API returns JSON successfully

Try this (inserting the full path url) in the get method:

request
  .get('http://localhost:3000/api/getStudents')
  .set('Accept', 'application/json')
  .end(function(err, res) {
    if (err) {
      console.log("There's been an error: getting students.");
      console.log(err);
    } else {
      return res;
    }
  });

Check out the documentation for CORS for an example of using absolute urls:

https://visionmedia.github.io/superagent/#cors