The js-cookie library manages browser cookies easily. Cookies.set('name', 'value', {expires: 7}) creates a 7-day cookie. Use the secure and httponly options for sensitive cookies that should not be accessible to JavaScript.
Cookies with jQuery Cookie
// Install
npm install js-cookie
import Cookies from 'js-cookie';
Cookies.set('theme', 'dark', { expires: 7 });
Cookies.get('theme'); // 'dark'
Cookies.remove('theme');