schon/storefront/plugins/apollo.ts

import { from, ApolloLink } from '@apollo/client/core';
import { onError } from '@apollo/client/link/error';
import { setContext } from '@apollo/client/link/context';
import { provideApolloClient } from '@vue/apollo-composable';
import createUploadLink from "apollo-upload-client/createUploadLink.mjs";
import { useAppConfig } from '~/composables/config';

export default defineNuxtPlugin((nuxtApp) => {
  const runtime = useRuntimeConfig();
  const { $apollo } = nuxtApp as any;

  const errorLink = onError((err) => {
    nuxtApp.callHook('apollo:error', err);
  });

  const authLink = setContext(async (_, { headers }) => {
    const localeCookie = useCookie(useAppConfig().COOKIES_LOCALE_KEY);
    const token = useCookie(useAppConfig().COOKIES_ACCESS_TOKEN_KEY);

    const hdrs: Record<string,string> = {
      ...headers,
      'Accept-Language': localeCookie.value || 'en-gb'
    };

    if (token.value) {
      hdrs['X-SCHON-AUTH'] = `Bearer ${token.value}`;
    }

    return { headers: hdrs };
  });

  const customLink = new ApolloLink((operation, forward) => {
    return forward(operation).map((data) => {
      return data;
    });
  });

  const httpLink = createUploadLink({
    uri: `https://api.${runtime.public.schonBaseDomain}/graphql/`
  });

  $apollo.defaultClient.setLink(from([
    errorLink,
    authLink,
    customLink,
    httpLink,
  ]));

  provideApolloClient($apollo.defaultClient);
});