Build a Storage-Agnostic GraphQL Gateway in Python (FastAPI + Pydantic + Supabase + Firebase)
🧠 Role & Perspective: Act as a backend architect building a modular GraphQL API gateway in Python 3.11+, using FastAPI, Strawberry, Pydantic v2, and Poetry.
🎯 Goal: Develop a GraphQL API that:
Authenticates users via Supabase JWT
Aggregates data from Supabase, Redis, Firebase (Firestore), and future backends
Uses Pydantic models for all data contracts
Implements adapter-based storage architecture with pluggable NoSQL and SQL connectors
Returns GraphQL responses only (REST optional but not required)
🛠 Constraints: Language: Python 3.11+
Runtime: FastAPI
Package Manager: Poetry
Models: Pydantic v2
Auth: Supabase JWT via middleware
API Format: GraphQL using Strawberry (or Ariadne)
Persistence Layer: Abstracted adapter pattern for:
Supabase (SQL)
Redis (cache)
Firebase/Firestore (NoSQL)
Future DBs like MongoDB, DynamoDB
All adapters must conform to the same interface (AbstractStorageAdapter)
Async throughout
🔁 Chain of Execution: Project Bootstrapping
Scaffold via Poetry
Setup FastAPI + Strawberry + Pydantic v2
Install adapters: Supabase, Firestore, Redis
Authentication
Middleware to verify Supabase JWT
Attach user claims to request context
GraphQL Schema
Define all query/mutation types via Strawberry
Types must be backed by Pydantic models
Adapter Layer
Define AbstractStorageAdapter (interface)
Implement:
SupabaseAdapter
RedisAdapter
FirestoreAdapter
Allow runtime selection via config or DI
Models
Define all IO schemas using Pydantic v2
Use .model_validate() and .model_dump() consistently
Resolvers
Authenticate via request context
Query data through selected adapter only
Return GraphQL Pydantic-wrapped response
Testing
Use Pytest
Mock Supabase/Firebase/Redis clients
Add edge case coverage for: timeout, adapter failover, data mismatch
DevOps
Dockerfile + docker-compose.yml
.env config system to pick storage engine
Firebase key file via volume or secret mount
💡 GraphQL Query Example graphql Copy Edit query { user(id: "abc123") { id fullName email recentActivity { timestamp action } } } Edge-Case Coverage Firebase document not found
Redis cache miss or failure
Supabase downtime
Switching from SQL → NoSQL with no code refactor
JWT expired or missing roles
Reusable For: Cross-service GraphQL API orchestration
Serverless-compatible APIs
Real estate, SaaS, AI dashboards, mobile backends
Firebase + Supabase hybrid stack