FastAPI and Firebase Comparison

Compare Firebase with FastAPI + Supabase for development effort, cost, and security.

Here’s a concise comparison of Firebase vs. FastAPI + Supabase for your residential data app, focusing on development effort, cost, and security:

---

1. Development Effort

Criteria	Firebase	FastAPI + Supabase
Backend Code	Minimal (Firestore rules, Cloud Functions)	Moderate (write FastAPI routes, SQL)
Auth	Built-in (LINE, Google, etc.)	LINE Login + Supabase Auth (or JWT)
Database	NoSQL (Firestore) – schema-less	PostgreSQL (SQL) – structured
Offline Support	Automatic (Firestore SDK)	Manual (Android Room + sync logic)
APIs	Client directly accesses Firestore	Define explicit REST/GraphQL APIs

Winner:

• Firebase for speed, FastAPI+Supabase for control.

---

2. Cost (Low User Count)

Criteria	Firebase	FastAPI + Supabase
Backend Hosting	Free tier (pay per read/write)	Free (Render, Fly.io) or ~$5/mo VPS
Database	~$0.06/100K reads, $0.18/100K writes	Supabase free tier (500MB DB)
Auth	Free <50K MAU	Free (Supabase Auth or LINE Login)
Bandwidth	Paid after 10GB/day	Often included in VPS

Winner:

• Tie (both cheap for small-scale), but Firebase scales expensively.

---

3. Security

Criteria	Firebase	FastAPI + Supabase
Auth	Google-managed (OAuth, MFA)	Supabase Auth or custom JWT
Database Rules	Firestore security rules (declarative)	PostgreSQL row-level security (SQL)
API Security	N/A (client talks directly to DB)	FastAPI middleware (explicit checks)
Attack Surface	Larger (client-side queries)	Smaller (only exposed APIs)

Winner:

• FastAPI+Supabase (more control), but Firebase is secure if rules are strict.

---

When to Choose Which?

Firebase is better if:

• You want to ship fast (no backend code).
• Your app is simple CRUD (no complex queries).
• You’re okay with vendor lock-in.

FastAPI + Supabase is better if:

• You need SQL (e.g., time-series analytics).
• You want control over APIs and security.
• You plan to self-host later.

---

Example Tradeoffs

• Firebase:

  // Client-side code (less secure)
  db.collection("readings").where("userId", "==", firebase.auth().currentUser.uid);

  • ✅ 1 hour to set up
  • ❌ Hard to audit who accessed data.

• FastAPI+Supabase:

  # Server-side control
  @app.get("/readings")
  async def get_readings(user: User = Depends(get_current_user)):
      return db.query(Readings).filter(Readings.user_id == user.id)

  • ✅ Audit-ready
  • ❌ 1-2 days to build.

---

Final Recommendation

• Prototype Phase: Use Firebase (launch in days).
• Production with Scalability: FastAPI + Supabase (long-term flexibility).