Koa JavaScript

import Koa from 'koa';
import Router from '@koa/router';

const GIF = Buffer.from('R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw==', 'base64');

const app = new Koa();
const router = new Router();

router.get('/pixel.gif', (ctx) => {
  ctx.type = 'image/gif';
  ctx.set('Cache-Control', 'no-store');
  ctx.body = GIF;
});

app.use(router.routes()).listen(8080);