What’s your ideal TTL for idempotency keys?

Double charging because of a timed out response is a quick way to lose customer trust. Using idempotency keys is definitely the right fix here.

We usually keep key cached for 24 hours in Redis long enough to cover slow retries or script re-runs, but short enough to keep storage lightweight.

If a request comes in after that it's treated as fresh. Curious if you've seen high storage overhead keeping those keys around longer?