Payment Processing API

This project is an asynchronous payment processing API built with FastAPI. It handles payment transactions in the background, integrates with external services (for loyalty and notifications), and uses separate databases for user balances and payment records.

Features

• Asynchronous Processing: Uses FastAPI with background tasks for non-blocking operations.
• Database Separation: Maintains user (wallet) data and payment records in separate databases.
• Reliable Transactions: Implements custom retry logic and explicit transaction management.
• External Service Integration: Communicates with external APIs for loyalty rewards and notifications.

Database Initialization

Before starting the application, initialize the databases if they do not exist. The database initialization script is located at app/utils/db/init.py.

To run the initialization script, execute:

python -m app.utils.db.init

Running the Application

To run the application using uvicorn:

uvicorn app.main:app --host $HOST --port $PORT --reload

Alternatively, you can run it via:

python -m app.main

Running External Services

Loyalty Service

python -m app.services.loyalty

or using uvicorn:

uvicorn app.services.loyalty:app --host 0.0.0.0 --port 8001 --reload

Notification Service

python -m app.services.notification

or using uvicorn:

uvicorn app.services.notification:app --host 0.0.0.0 --port 8002 --reload

Below is an example command for running a PostgreSQL database in Docker:

docker run --name test-pg-15 -p 5432:5432 -e POSTGRES_USER=testuser -e POSTGRES_PASSWORD=testpass -e POSTGRES_DB=test -d postgres:15