Initial load and store

_app.js

import App, {Container} from 'next/app'
import React from 'react'

const isServer = typeof window === 'undefined'
const clientStore = isServer ? null : {}

// mock of your actual data fetching solution
async function someFetch() {
	return {}
}

export default class MyApp extends App {
	static async getInitialProps ({ Component, router, ctx }) {
		let pageProps = {}

		let appData = clientStore ? clientStore.appData : await someFetch()

		if (Component.getInitialProps) {
			pageProps = await Component.getInitialProps(ctx)
		}

		return {appData, pageProps}
	}

	constructor(props) {
		super(props)

		if(clientStore && !clientStore.appData) {
			clientStore.appData = props.appData
		}
	}

	render () {
		const {Component, pageProps} = this.props
		return <Container>
			<Component {...pageProps} />
		</Container>
	}
}