With Postman, you’ll create a POST request, set the URL to and set the body to be “Raw” and “JSON”. You can either use a graphical tool such as Postman (free download) or the command line curl tool (may be installed with your operating system already). You can try the GET routes in a browser, but for the POST route you’ll need something else. So in this case, we’re using app.get('/', (req, res) =>. In Express, each route is serviced by a function that expects a req (request) and res (response) object… to tell Express when to invoke that function we pass it and a URL path as parameters to a function on the Express application object that corresponds to the HTTP verb to use. This route is served on the / URL, and the code looks like this: Routes are functions that tell Express what to do when a HTTP request with a matching URL pattern is received by the server. If none was set, we declared this up top to default to 3000.

The last line of code ( app.listen) tells Express to listen for HTTP requests on the port that we set in our environment variable. I then tell Express we want to use its JSON body parsing functionality (this will take the body of incoming POST requests and turn it into a JavaScript object for us): I get the port number that Express will listen on from an environment variable, and set up an empty JavaScript object to represent the “database”. The video provides a complete run through of how the code in server.js works, so here’s a summary… Setting up an Express Serverįirst up, I require Express and initialize it.

Our API will include functionality to set a key to a value, retrieve the value stored at a given key, and ask the database for information about things like the number of keys in use.

Express server