Creating an API

Your web server is pretty limited for now, handling only one route and always returning the same string. Let’s create your own little API by publishing some data in JSON format.

Enabling AJAX requests

Authorizing cross-origin requests on your server is mandatory to accept AJAX calls from clients. Enabling CORS on an Express web server is done by the following code:

// Enable CORS (see https://enable-cors.org/server_expressjs.html)
app.use((req, res, next) => {
  res.header("Access-Control-Allow-Origin", "*");
  res.header(
    "Access-Control-Allow-Headers",
    "Origin, X-Requested-With, Content-Type, Accept"
  );
  next();
});