firebase_skill

Overview

This skill packages opinionated Firebase patterns for Firestore, Authentication, Storage, real-time listeners, and security rules. It emphasizes security-first, spec-driven setup with emulators and TypeScript-ready code. The guidance focuses on denormalized data models, offline support, and scalable access patterns.

How this skill works

It provides initialization snippets for the modular Firebase SDK, emulator wiring for local development, and reusable CRUD and realtime listener functions. It includes data modeling recommendations (when to denormalize, use subcollections, and maintain aggregation counters) plus security rule templates and unit test examples for rules. Cloud Functions, offline persistence, and common auth flows are covered to integrate backend logic and client sync.

When to use it

• Building web or mobile apps that need realtime sync and offline support
• When you want a security-first Firestore schema with rules and tests
• Starting a TypeScript React or Node project with Firebase emulators
• When you need patterns for denormalization, pagination, and counters
• If you require file uploads gated by Storage rules and auth

Best practices

• Design data for access patterns: denormalize read-essential fields and use subcollections for unbounded lists
• Keep security rules as the canonical server-side validation and write unit tests with the rules-unit-testing SDK
• Use emulators for Firestore, Auth, and Storage during development and CI
• Store aggregated counters in parent documents and update them via Cloud Functions to avoid heavy reads
• Enable multi-tab IndexedDB persistence for reliable offline behavior and surface metadata to detect pending writes

Example use cases

• Social feed: denormalized posts with comments as a subcollection and a like counter updated by functions
• Chat app: messages in subcollections, realtime listeners for inbox updates, and messageCount aggregations
• E-commerce: orders with embedded bounded items, denormalized user email for display, and secure storage for receipts
• Admin panel: rules that allow admin tokens to delete content while preventing users from changing ownership
• Offline-first PWA: enable IndexedDB persistence and sync local writes when connectivity returns