Google Firebase

Overview

Firebase provides app backend services — Firestore database, Auth, Storage, Cloud Functions, and more — with REST APIs for each. Auth uses the project’s API key (a request to a non-existent project returns 404, verified — the REST API is alive).

Quick Start

Firestore REST (replace PROJECT_ID, YOUR_KEY):

curl "https://firestore.googleapis.com/v1/projects/PROJECT_ID/databases/(default)/documents" \
  -H "Authorization: Bearer YOUR_TOKEN"

{ "documents": [] }

Note: the API key pattern is ?key=YOUR_KEY for some services, Bearer OAuth token for others — see each service’s docs.

Authentication

• API key: Firebase console → Project settings → Web API Key.
• For user-scoped data, use Firebase Auth tokens (Bearer).
• Missing project returns 404 (verified) — not a “service down” signal.

Rate Limits & Notes

• Free tier (Spark plan): generous quotas per service (Firestore 20k writes/day, etc.); paid plans scale.
• Services with REST APIs: Firestore, Realtime Database, Auth, Storage, Remote Config, FCM.
• REST is useful for server-side access; SDKs are recommended for clients.
• This is a BaaS — the “API” is your project’s data, so no global demo data exists.

FAQ

Is Firebase free? Spark plan is free with quotas; usage beyond is billed.

How do I get a key? Firebase console → Project settings → Web API Key.

Why 404 on Firestore? A wrong/nonexistent project ID returns 404 (verified) — check your project.