I wanted to know if there is any way to monitor cloud firestore security rules changes. For example I want to know which user / service account changed the rules and at what time.
The Cloud Audit log service logs only admin related activities but nothing related to security rule changes.
firebaser here
No audit trail is currently kept for changes to Firestore security rules. It's a valid feature request though, and might even be integrated into the exiting version history for rules. I recommend you file a feature request.