Hey Lemmy!
Exactly as the title says.
I'm a user, not a server admin, so this is about deleting messages I've sent rather than cleaning old messages on a server. Ideally I'm looking for a script which I can run on a timer once a day, and each time it runs, it will delete all my messages, or my messages in some specified rooms, that are older than say two weeks. Basically an automated finger that presses the delete button repeatedly.
I know about m.room.retention but I don't want to have to set it for every room. And it doesn't seem to be reliable; it doesn't work in a matrix.org test room I set up with one minute retention. Even when I cleared the cache.
The closest I've found is this branch, but as this issue mentioned, it purges all messages rather than only messages older than X time.
If no one has a better script, I'll write one myself or fork the above script. But in case anyone here's already gone to the trouble... I won't have to learn the Matrix API :)
Edit 1:
I did make the script, but it's slow; each message deletion sent to matrix.org has to wait about 4 seconds due to rate limiting. I send a lot of messages per day, so it's barely an acceptable solution.
The whole concept also feels awkwardly inefficient because I have to send a request for each message, rather than the server and clients running their own timers.
I moved to Delta Chat for now, for its disappearing messages.
I found some nice comparison tables of instant messaging services that could be of use:
not sure about standard, but privacyguides.org has some nice resources for getting started. I recommend their "threat model" resource in particular; it shows you what direction you should work towards depending on your privacy goals.
Privacy Guides has an Android page as well.