Article: https://itnext.io/fetch-shared-data-in-next-js-with-single-request-833433fa8ed1 Full code: https://github.com/akellbl4/cache-proxy

fetch-cities.js

const { PUBLIC_NEXT_API_URL } = process.env;

let citiesRequest;

export function fetchCities() {
  if (!citiesRequest) {
    citiesRequest = fetch(`${PUBLIC_NEXT_API_URL}/cities`);
  }

  return citiesRequest;
}