
About
Firebase gives you a complete backend in minutes - auth, database,
name: firebase description: Firebase gives you a complete backend in minutes - auth, database, storage, functions, hosting. But the ease of setup hides real complexity. Security rules are your last line of defense, and they're often wrong. risk: unknown source: vibeship-spawner-skills (Apache 2.0) date_added: 2026-02-27
Firebase
Firebase gives you a complete backend in minutes - auth, database, storage, functions, hosting. But the ease of setup hides real complexity. Security rules are your last line of defense, and they're often wrong. Firestore queries are limited, and you learn this after you've designed your data model.
This skill covers Firebase Authentication, Firestore, Realtime Database, Cloud Functions, Cloud Storage, and Firebase Hosting. Key insight: Firebase is optimized for read-heavy, denormalized data. If you're thinking relationally, you're thinking wrong.
2025 lesson: Firestore pricing can surprise you. Reads are cheap until they're not. A poorly designed listener can cost more than a dedicated database. Plan your data model for your query patterns, not your data relationships.
Principles
- Design data for queries, not relationships
- Security rules are mandatory, not optional
- Denormalize aggressively - duplication is cheap, joins are expensive
- Batch writes and transactions for consistency
- Use offline persistence wisely - it's not free
- Cloud Functions for what clients shouldn't do
- Environment-based config, never hardcode keys in client
Capabilities
- firebase-auth
- firestore
- firebase-realtime-database
- firebase-cloud-functions
- firebase-storage
- firebase-hosting
- firebase-security-rules
- firebase-admin-sdk
- firebase-emulators
Scope
- general-backend-architecture -> backend
- payment-processing -> stripe
- email-sending -> email
- advanced-auth-flows -> authentication-oauth
- kubernetes-deployment -> devops
Tooling
Core
- firebase - When: Client-side SDK Note: Modular SDK - tree-shakeable
- firebase-admin - When: Server-side / Cloud Functions Note: Full access, bypasses security rules
- firebase-functions - When: Cloud Functions v2 Note: v2 functions are recommended
Testing
- @firebase/rules-unit-testing - When: Testing security rules Note: Essential - rules bugs are security bugs
- firebase-tools - When: Emulator suite Note: Local development without hitting production
Frameworks
- reactfire - When: React + Firebase Note: Hooks-based, handles subscriptions
- vuefire - When: Vue + Firebase Note: Vue-specific bindings
- angularfire - When: Angular + Firebase Note: Official Angular bindings
Patterns
Modular SDK Import
Import only what you need for smaller bundles
When to use: Client-side Firebase usage
MODULAR IMPORTS:
""" Firebase v9+ uses modular SDK. Import only what you need. This enables tree-shaking and smaller bundles. """
// WRONG: v8-compat style (larger bundle) import firebase from 'firebase/compat/app'; import 'firebase/compat/firestore'; const db = firebase.firestore();
// RIGHT: v9+ modular (tree-shakeable) import { initializeApp } from 'firebase/app'; import { getFirestore, collection, doc, getDoc } from 'firebase/firestore';
const app = initializeApp(firebaseConfig); const db = getFirestore(app);
// Get a document const docRef = doc(db, 'users', 'userId'); const docSnap = await getDoc(docRef);
if (docSnap.exists()) { console.log(docSnap.data()); }
// Query with constraints import { query, where, orderBy, limit } from 'firebase/firestore';
const q = query( collection(db, 'posts'), where('published', '==', true), orderBy('createdAt', 'desc'), limit(10) );
Security Rules Design
Secure your data with proper rules from day one
When to use: Any Firestore database
FIRESTORE SECURITY RULES:
""" Rules are your last line of defense. Every read and write goes through them. Get them wrong, and your data is exposed. """
rules_version = '2'; service cloud.firestore { match /databases/{database}/documents {
// Helper functions
function isSignedIn() {
return request.auth != null;
}
function isOwner(userId) {
return request.auth.uid == userId;
}
function isAdmin() {
return request.auth.token.admin == true;
}
// Users collection
match /users/{userId} {
// Anyone can read public profile
allow read: if true;
// Only owner can write their own data
allow write: if isOwner(userId);
// Private subcollection
match /private/{document=**} {
allow read, write: if isOwner(userId);
}
}
// Posts collection
match /posts/{postId} {
// Anyone can read published posts
allow read: if resource.data.published == true
|| isOwner(resource.data.authorId);
// Only authenticated users can create
allow create: if isSignedIn()
&& request.resource.data.authorId == request.auth.uid;
// Only author can update/d

