Filestack’s CDN caches Filestack URLs the first time they are accessed, such as in the case of storage aliases or transformations. The cached copy of any unique Filestack URL will live for 30 days – it will then be re-cached only when it is requested again.
If desired, you can bypass the cache (retrieve a file directly from its storage location) by adding the /cache=false/ task to your URL:
https://cdn.filestackcontent.com/cache=false/HANDLE
If you would like to explicitly control how long the file stays cached, you may specify an expiry in seconds:
https://cdn.filestackcontent.com/cache=expiry:value/HANDLE