What is the lifetime of a Transcript URL?

I'm in the process of implementing the API within my product and as part of the workflow I'm going to GET Transcript URLs once we have the webhook fire with the 'recap_summary' state. All good.

However, does anyone know the lifetime of these URLs? Presumably the call log in Dialpad is infinite, so presumably as long as the call is never deleted from the call log, the URL will always be valid?