This is an experimental protoc plugin that generates Firebase Rules for Cloud Firestore based on Google's Protocol Buffer format. This allows you to easily validate your data in a platform independent manner.
@talamaska Bolt was a project to generate rules for the Firebase Realtime Database. This project generates rules for Cloud Firestore / Cloud Storage which both use a different (newer) rules language.
Except that it is based on protobuf 2 or 3, what else this has in addition? How it is different from Bolt?