apollo-client.js

import { ApolloClient, createHttpLink, InMemoryCache } from "@apollo/client";
import { setContext } from '@apollo/client/link/context'
import { API_URL } from "./config";

const httpLink = createHttpLink({
  uri: API_URL,
})

const authLink = setContext((_, { headers }) => {
  // get the authentication token from local storage if it exists
  const token = localStorage.getItem('authtoken');
  // return the headers to the context so httpLink can read them
  return {
    headers: {
      ...headers,
      authorization: token ? `JWT ${token}`: '',
    },
  }
})

const client = new ApolloClient({
  link: authLink.concat(httpLink),
  cache: new InMemoryCache(),
})

export default client