Download the example or clone the repo:

curl https://codeload.github.com/zeit/next.js/tar.gz/master | tar -xz --strip=2 next.js-master/examples/with-sw-precache
cd with-sw-precache

Install it and run:

npm install
npm run build
npm start

Deploy it to the cloud with now (download)

now

You'll often want your Service Worker to be registered at the root level to give it access to your whole application.

This example shows how this can be achieved alongside sw-precache (via the webpack plugin).