sanity.js

import {
    createClient,
    createCurrentUserHook,
} from "next-sanity";
import imageUrlBuilder from '@sanity/image-url'
export const config = {
    /*
    Find your projectID and dataset in `sanity.json` in your studio project.
    these are considered "public", but you can use environment variables
    if you want differ between local dev and production

    https://nestjs.org/docs/basic-features/environment-variables
   */
  dataset: process.env.NEXT_PUBLIC_SANITY_DATASET || "production",
  projectId: process.env.NEXT_PUBLIC_SANITY_PROJECT_ID,
  apiVersion: "2021-03-25",
  /*
  Set useCdn to `false` if your application require the freshest possible
  data always (potentially slightly slower and a bit more expensive).
  Authenticesed request (like preview) will always bypass the CDN.
  */
 useCdn: process.env.NODE_ENV === "production",
}
// set up the client for fetching data in the getProps page function
export const sanityClient = createClient(config);

/* 
  Set up a helper function for generating Image URLs with only the asset
  reference dta in your documents.
  Red more: https://www.sanity.io/docs/image-url
*/
const builder = imageUrlBuilder(sanityClient)
export const urlFor = (source) => builder.image(source);

// helper function for using the current logged in user account
export const useCurrentUser = createCurrentUserHook(config);