Firebase Platform AI Skill Guide (Claude)

Overview & Engine Architecture

Firebase sits on a Google Cloud project: Auth, Firestore / Realtime Database, Storage, Cloud Functions, Hosting, and FCM. Client config is public; authorization is Security Rules + ID tokens, not obscurity. The Admin SDK bypasses Rules and must stay server-only. Agents write Rules first, test with the Emulator Suite, never set FIREBASE_AUTH_EMULATOR_HOST in production, and remember the Firestore emulator does not enforce composite indexes.