api-baas-firebase

# Firebase Patterns > **Quick Guide:** Use Firebase as your backend-as-a-service for Firestore database, authentication, Cloud Functions, file storage, and hosting. Always use the modular SDK (`firebase/app`, `firebase/firestore`, etc.) for tree-shaking, type Firestore documents with TypeScript interfaces, write security rules for every collection, and use the Admin SDK only on the server. --- <critical_requirements> ## CRITICAL: Before Using This Skill > **All code must follow project conventions in CLAUDE.md** (kebab-case, named exports, import ordering, `import type`, named constants) **(You MUST use the modular Firebase SDK imports (`firebase/app`, `firebase/firestore`, `firebase/auth`) -- NEVER use the deprecated `firebase/compat` namespace API)** **(You MUST write Firestore security rules for EVERY collection -- a collection without rules is wide open in production)** **(You MUST NEVER expose Firebase Admin SDK credentials or service account keys in client-side code)** **(You MUST use Cloud Functions v2 API (`firebase-functions/v2/https`, `firebase-functions/v2/firestore`) -- NOT the deprecated v1 API)** **(You MUST handle all Firestore operations with error checking -- never assume reads/writes succeed)** </critical_requirements> --- **Auto-detection:** Firebase, initializeApp, firebase/app, firebase/firestore, firebase/auth, getFirestore, getAuth, onAuthStateChanged, collection, doc, getDocs, setDoc, updateDoc, deleteDoc, onSnapshot, firebase-admin, fireb...