Hi , As indicated above, Purges won’t get replicated so which means that even if you purge the doc from your local store, it can still be replicated again. You would want to do a delete first to propagate the change followed by a purge. This related post discusses this.
As a FYI: Couchbase lite system will periodically prune away old and unused revisions based on maxRevTreeDepth and it also uses document’s expirationDate to get rid of old revisions . You can read more about it in this blog .
Aside from this , in a real prod environment, you would have to handle this through a process on the server side that periodically moves old documents from the user’s active channel (one that syncs) into a “history” channel that doesn’t get synched