Edge Side Includes (ESI)

Edge Side Includes (or ESI for short) is a way to dynamically assemble content on a website. The content is injected by the server.

ESI uses the HTML tag <esi:include …> and is implemented by some content delivery networks (CDN) .

You can find more information on the Wikipedia page: Edge Side Includes .

Using Cloudflare

If your website uses the Cloudflare CDN , you can support ESI using https://github.com/xtuc/esi-cf-workers .

Deploy a Cloudflare Worker

From the Cloudflare dashboard or using wrangler create the following Worker:

import { withESI } from "esi-cf-workers"

export default {
  async fetch(request, env, ctx) {
    const res = await fetch(request)
    return withESI(res)
  },
};