Hey @CendioOssman, nice to see you here! I’m still regularly using novnc, thanks a lot for your work!
restic will automatically cache snapshot and index files and the files from the data/ subdir which only contains metadata. When you run prune to remove data from the repo, it is also removed from the local cache (either on the next run of restic or directly during prune, depending on where you run it). The cache only contains data which is still present in the repo, so there’s no stale data.
However, there’s no process to delete data from the cache which is still in the repo, but hasn’t been accessed for some time. So if you, for example, use a command like find or ls to check if some file is in the backup, it’ll download most of the metadata files from the repo, and those files will stay in the cache.
You can just delete the cache if it grows too large, restic will rebuild it. If some metadata is needed, it’ll download and save the whole file containing the metadata to the cache.
I’ve seen cache sizes varying from 3-10% of the whole repository size.
I hope this helps a bit!