How do you implement media previews and downloads in the portal?

How do you implement media previews and downloads in the portal?

A completed result needs more than a filename. The portal must retrieve the correct artifact and explain failures without exposing private storage.

Resolve the current artifact

Use the job’s confirmed result reference and request authorized access from the backend. Keep stable storage identifiers separate from temporary URLs. Show a preview only for a ready artifact and provide a useful state while access is being obtained.

Exercise playback and expiration

Test the generated file in the target browser, including audio, dimensions, and seeking where supported. If an access URL expires, request a fresh authorized URL rather than marking the underlying file missing. Handle deleted artifacts and storage errors distinctly. Verify that a second account cannot obtain the same private download by changing identifiers. Keep preview and download tied to the correct revision so a newly edited script does not imply the old video has changed.