Subscription Management Backend

A scalable, production-ready backend built with FastAPI, PostgreSQL, SQLAlchemy, Redis, and Celery to manage user subscriptions and plan lifecycles.

Deployed Demo

Access the live API at: http://ec2-13-201-98-2.ap-south-1.compute.amazonaws.com

Note: If you get a "connection refused" error, ensure you are accessing the API via http and not https.

API Documentation

For detailed API endpoints and schemas, visit the interactive Swagger docs at: http://ec2-13-201-98-2.ap-south-1.compute.amazonaws.com/docs

Features

• JWT Authentication (Login/Signup)
• Role-Based Access Control (Admin/User)
• Create, Update, Cancel Subscriptions
• Subscription Expiry handled by Celery Beat
• Admin-only Plan Management (Create/Update/Delete Plans)
• Full Test Suite with pytest and httpx
• Retry Logic on DB Failures (tenacity)
• Async support throughout
• Modular, maintainable project structure

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Tech Stack

• FastAPI - Async API framework
• PostgreSQL - Main relational database
• SQLAlchemy - Async ORM
• Alembic - DB migrations
• Pydantic - Schema validation
• Celery + Redis - Background tasks & task queue
• Docker - Containerization
• Pytest - Testing framework

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Project Structure

app/
├── auth/               # JWT Auth handlers & dependencies
├── models/             # SQLAlchemy models
├── schemas/            # Pydantic schemas
├── routers/            # FastAPI routers
├── services/           # Business logic
├── tasks/              # Celery tasks (e.g. subscription expiry)
├── utils/              # Helpers like retry logic
├── database.py         # Async engine and session
├── main.py             # Entry point
celery_worker.py        # Celery worker instance
alembic/                # DB migrations
tests/                  # Tests

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Running Tests

pytest

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Setup Instructions

# Clone the repo
$ git clone https://github.com/CodeWithDevesh/Subscription-Service
$ cd Subscription-Service

# Setup virtual environment
$ python -m venv .venv
$ source .venv/bin/activate
$ pip install -r requirements.txt

# Run DB migrations
$ alembic upgrade head

# Start Redis server (Docker recommended)
$ docker run -p 6379:6379 redis

# Start FastAPI app
$ uvicorn app.main:app --reload

# Start Celery worker
$ celery -A celery_worker.celery_app worker --loglevel=info

# Start Celery beat for periodic tasks
$ celery -A celery_worker.celery_app beat --loglevel=info

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Future Improvements

• Rate Limiting (slowapi)
• Swagger Auth for /docs
• Subscription emails (welcome, renewal, expiry notifications)

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