When installing SharePoint Framework solutions, SharePoint shows you the URLs of external scripts used by the solution. But it doesn't show all of them.
Many articles about building SharePoint Framework solutions mention uploading your files to a CDN. But are you sure you actually need one?
Interested in the SharePoint Framework? Join me at Microsoft Ignite 2017!
Now that you can build SharePoint Framework solutions for both SharePoint online and on-premises, you need to decide which one you want to target.