Koa minimal example

const Koa = require('koa');
const app = new Koa();

app.use(async ctx => {
  ctx.body = {status: 'success'};
});

app.listen(8080);

To install (see this previous post for a guide on installing NodeJS & NPM):

npm install --save koa
node index.js

Then go to http://localhost:8080/ to see the test page.