Permanent link

How it works

Nothing in HTTP expires a URL. Permanence is the absence of an expiry check. It is convenient and easy to forward forever. Pair it with revocation and access logs if the file matters.

A documentation file stays at one URL for two years. A leaked internal build uses the same pattern and is still downloading 14 months later. They add expiry on build links and leave the public manual permanent.

How it differs

Permanent is not private. A permanent public URL is a published file.

Search engines index permanent public links.

Do not use them for customer data.

On the ticket

• The practical close is a log line: time, actor, byte count, result.
• Without that line the transfer is a story.
• With it, the next person can see whether this door did what the ticket claimed.
• If the path is shared, say so in the partner profile so a later change does not silently pick a different limit, key, or region.
• On a real ticket, write down the door, the byte count, and the clock.
• For permanent link, that means naming the host or bucket, the expected size, and the time the other side must have a complete file.
• A progress bar is not that record.
• A 200 response that arrives before the complete call is not that record.
• If a retry is allowed, say how many and whether it resumes.
• If a person must approve the send, name the person.
• Partners who receive permanent link files should match on hash or size before they import.
• A same-length corrupt file passes a size check and fails a hash.
• Keep the published hash off the only channel an attacker can edit, or treat it as a corruption check rather than a substitution check.
• When the path changes, new key, new region, new cap, update the profile the same day so the next run does not use a stale limit.