QuickPay API 💳

QuickPay API is a backend wallet and payment system built using FastAPI and SQLAlchemy.
It simulates the core backend functionality of a digital payment platform, focusing on authentication, wallet management, and transaction handling.

This project was built as a backend-focused portfolio project to practice real-world API development, database modeling, and authentication workflows.

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Features

• JWT-based authentication
• Secure password hashing using bcrypt
• User registration & login
• Automatic wallet creation for users
• Add money to wallet
• Transaction history tracking
• Proper database relationships (User ↔ Wallet ↔ Transactions)
• Environment-based configuration for secrets

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🛠 Tech Stack

• Python
• FastAPI
• SQLAlchemy (ORM)
• SQLite (development database)
• Pydantic
• JWT (JSON Web Tokens)

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Project Structure

QuickPay-API/
│
├── app/
│ ├── api/
│ │ ├── auth_routes.py
│ │ └── wallet_routes.py
│ ├── auth.py
│ ├── config.py
│ ├── database.py
│ ├── models.py
│ ├── schemas.py
│ └── main.py
│
├── .gitignore
├── sample.env
└── README.md

Setup & Run Locally

Clone the repository

git clone https://github.com/TejasBLD/QuickPay-API.git
cd QuickPay-API

Create a virtual environment

python -m venv venv
venv\Scripts\activate   # Windows

Install dependencies

pip install -r requirements.txt

Run the application

uvicorn app.main:app --reload

Authentication Flow

1.Register a new user
2.Login to receive a JWT access token
3.Use the token in request via the header:

Authorization: Bearer <access_token>

4.Access protected wallet and transaction endpoints

API ENDPOINTS

Authentication

1.POST /api/auth/register — Register a new user
2.POST /api/auth/login — Login and get JWT token
3.GET /api/auth/me — Get current authenticated user

Wallet

1.GET /api/wallet — Get wallet details
2.GET /api/wallet/balance — Get wallet balance
3.POST /api/wallet/add-money — Add money to wallet

Transactions

1.POST/api/transaction-Allows P2P transactions
2.GET/api/transaction/history-Provides transaction history of the individual in descending order

Learning outcome

1.Implemented JWT authentication in FastAPI
2.Designed relational database models using SQLAlchemy
3.Built secure password handling using bcrypt
4.Managed environment variables securely using .env
5.Handled real-world ORM bugs and schema mismatches
6.Designed business logic beyond basic CRUD APIs 

Currently working on:

1.Transaction rollback handling
2.Alembic database migrations
3.Role-based access control (Admin/User)
4.Unit & integration testing
5.Rate limiting and security hardening