const res = await fetch('https://nodejs.org/api/documentation.json');

if (res.ok) {

const data = await res.json();

console.log(data);

}

The implementation is based upon [undici](https://undici.nodejs.org), an HTTP/1.1 client

written from scratch for Node.js. You can figure out which version of `undici` is bundled

in your Node.js process reading the `process.versions.undici` property.

You can use a custom dispatcher to dispatch requests passing it in fetch's options object.

The dispatcher must be compatible with `undici`'s

[`Dispatcher` class](https://undici.nodejs.org/#/docs/api/Dispatcher.md).

fetch(url, { dispatcher: new MyAgent() });

It is possible to change the global dispatcher in Node.js installing `undici` and using

the `setGlobalDispatcher()` method. Calling this method will affect both `undici` and

Node.js.

import { setGlobalDispatcher } from 'undici';

setGlobalDispatcher(new MyAgent());

The following globals are available to use with `fetch`:

* [`FormData`](https://nodejs.org/api/globals.html#class-formdata)

* [`Headers`](https://nodejs.org/api/globals.html#class-headers)

* [`Request`](https://nodejs.org/api/globals.html#request)

* [`Response`](https://nodejs.org/api/globals.html#response).