📙 Use it as Library

For those cases in which you want to add Edge-Resizer capabilities to your existing worker, required with npm or yarn

npm i -D edge-resizer
yarn add -D edge-resizer

It's up to you where to have Edge-Resizer's router handle the request, but when you do, make sure you instance it with the proper ROUTE_PREFIX (it should have a leading slash. In this scenario there's no route normalization involved).

Parameters to the handle method are pretty generic: the ubiquitous Request, and an object the waitUntil method. The latter would be the event if using service-worker format, and context when using module format.

Example: Format Service-Worker

import {ResizerRouter} from 'edge-resizer'

addEventListener('fetch', async (event: FetchEvent) => {
  const  resizeRouter=new ResizerRouter({ ROUTE_PREFIX: '/thumbnails' })
  event.respondWith(resizeRouter.handle(event.request, event))

Example: Format Modules

If your worker is using the module format:

import {ResizerRouter} from 'edge-resizer'

export default {
    fetch:(request, env, context) => {
        const resizeRouter=new ResizerRouter({ ROUTE_PREFIX: env.ROUTE_PREFIX || '/thumbnails' })
        return resizeRouter.handle(request, context)


In the examples above, both the FetchEvent found in classic ServiceWorker format, as well as the context objet as seen in Module format implement the waitUntil method, which is the only enforced interface contract.


In the examples above, eventhough resizeRouter is a full blown itty-router instance, it has a catch-all handler already declared (and it just forwards the request). Therefore don't expect it to handle additional routes.