I think a useful node to have would be one which takes as input information from the current workflow run and compares it to a previous workflow run. Basically an easy way to tell “did something change?”
I think n8n would be great to use to get alerts from things online that don’t support alerts on their own, but it turns out knowing whether anything has changed is a big part of that. Even something ‘straightforward’ like sending an alert when an RSS feed includes a given search term would end up triggering endlessly so long as the term remains in the feed.
I imagine it looking and working similar to the “IF” node’s “string” condition. Perhaps one could even select whether it would compare to “Last run”, “Any time in last x runs” or “any time in last x days”.
Hope that this makes sense and is in the appropriate forum.