cross domain localstorage with javascript

Question

We have a javascript api.js which is hosted on domain api.abc.com. It manages the local storage.

We included this javascript in our websites at abc.com and login.abc

Answer 1

As noticed in your post the localStorage (sessionStorage too) won't be stored on the storage related to the domain api.abc.com. If this was the case, by using CDN version of a library using localStorage you would have to share storage with all the other websites using this library.

One good solution could be to use an iframe with postMessage as explained in the following stack overflow: use localStorage across subdomains