Next.js

Hydration

Jotai has support for hydration of atoms with useHydrateAtoms. The documentation for the hook can be seen here.

Sync with router

It's possible to sync Jotai with the router. You can achieve this with atomWithHash:

const pageAtom = atomWithHash('page', 1, {
  replaceState: true,
  subscribe: (callback) => {
    Router.events.on('routeChangeComplete', callback)
    window.addEventListener('hashchange', callback)
    return () => {
      Router.events.off('routeChangeComplete', callback)
      window.removeEventListener('hashchange', callback)
    }
  },
})

This way you have full control over what router event you want to subscribe to.

You can't return promises in server side rendering

It's important to note that you can't return promises with SSR - However, it's possible to guard against it inside the atom definition.

If possible use useHydrateAtoms to hydrate values from the server.

const postData = atom((get) => {
  const id = get(postId)
  if (isSSR || prefetchedPostData[id]) {
    return prefetchedPostData[id] || EMPTY_POST_DATA
  }
  return fetchData(id) // returns a promise
})

Provider

Because of the nature of SSR, your app can have more instances existing in JS memory in the same time. You need to wrap your app inside a Provider (view more details in the Core section) so that each instance has its own state and will not interfere with previous values from a default store (provider-less mode).

Examples

Clock

HN Posts

Next.js repo

npx create-next-app --example with-jotai with-jotai-app
# or
yarn create next-app --example with-jotai with-jotai-app

Here's a link.