All content here is taken from Discord. Messages are cached internally until Discord deems the contents invalid, either by:
The sitemap is cached for six hours. People will be able to find the message IDs of previously served messages this way, but they will not be able to use the service to get the contents of these messages. The bot leaving your server does not invalidate the cache until it is regenerated, unless the program is restarted in between those six hours.
Updates to this policy will be announced in the Discord server linked on the main page.