We take advantage of the new Node.js features like `async/await` from ES2017 and the awesome `yarn` package-manager to create modern JSON APIs with Koa v2. Make sure you have at least Node.js 7.6.x installed. The `ctx` (context) variable encapsulates a _Request_ and _Response_ object, they are similar to what we already know about the `req` and `res` objects from the Express.js framework, but it is more expressive and easy to understand thanks to its _getters, _setters_ and some shortcuts. It also parses the response content and sets the `Content-Type` header based on the type of its body property. Finally, we can manually set the response headers and status code. The HTTP client from the video is [wuzz](https://github.com/asciimoo/wuzz).