Do you have that code posted somewhere by chance? I would be interested in browsing through it!

Not right now, no. It's fairly simple (login to Bluesky, read RSS, save item IDs to a text file, post if there are any new feed items, close program then systemd timers run this every N minutes) + pretty specific to AEMET and their formats.

If there is interest I guess I could spend some hours to make it a bit more generic and publish the source.