Overview

This is a backend service for managing user accounts and transactions, including recurring payments.

Features

• User Registration and Authentication:

  • POST /auth/signup - Register a new user
  • POST /auth/signin - Sign in a user
  • POST /auth/signout - Sign out a user

• Account Management:

  • GET /api/accounts - View all user's account details and balances
  • POST /api/accounts - Create new user's account
  • GET /api/accounts/{id}/history - View specific account transaction history

• Transaction:

  • POST /api/send - Send funds from one account to another
  • POST /api/withdraw - Withdraw funds from an account
  • Note: Transactions (send and withdraw) are processed x seconds after the endpoint is hit. The value of 'x' can be adjusted in the '.env' file.

• Recurring Payments:

  • GET /api/recurring-payments - Retrieve all recurring payments
  • PUT /api/recurring-payments{id} - Set up or update recurring payments

Tech Stack

• Node.js with TypeScript
• Fastify for the API server
• Prisma as the ORM
• PostgreSQL for the database
• SuperTokens for authentication
• Swagger for API documentation

Getting Started

Prerequisites

• Node.js (v20 or later)
• PostgreSQL (v14 or later)

Installation

1. Clone the Repository:

   git clone https://github.com/andregit1/payment-system.git
   cd payment-system

2. Install Dependencies:

   npm install

3. Set Up Environment Variables: Create a .env file in the project root with the following content:

   DATABASE_URL="postgresql://root:123123123@localhost:5432/concreteai_dev?schema=public"  # for local
   DATABASE_URL="postgresql://root:123123123@db:5432/concreteai_dev?schema=public"         # with Docker
   

4. Set Up the Database: Run the following command to apply database migrations:

   npx prisma migrate dev

5. Start the Server:

   npm run dev

   The API server should now be running at http://localhost:3001.

Seed Data (Optional)

To seed the database with initial data, add the following to your package.json:

"prisma": {
  "seed": "ts-node-dev prisma/seed.ts"
}

Then, run the seed command:

npx prisma db seed

API Documentation

API documentation is available at http://localhost:3001/documentation when the server is running.

Demo Video Link: swagger-authorized-demo

Accessing Authorized API Documentation

1. Open the Swagger UI: Navigate to http://localhost:3001/documentation in your browser to access the API documentation.

2. Sign Up and Sign In:

   • Use the POST /auth/signup endpoint to create a new user account.
   • Use the POST /auth/signin endpoint to sign in and obtain an access token from the response.

3. Authorize with the Token:

   • Copy the st-access-token value from the response header of the POST /auth/signin request.
   • Click the Authorize button in the Swagger UI (usually located in the top right corner).
   • Paste the token value into the authorization dialog and click Authorize.
   • Click Close to exit the authorization dialog.

Now, you can use the Swagger UI to test the endpoints with the provided authorization.

Running in Development with Docker

To run the application using Docker:

1. Build the Docker Images:

   docker compose build

2. Start the Docker Containers:

   docker compose up -d

3. Access the Docker Container:

   docker compose exec app sh

4. Stop the Docker Containers:

   docker compose down

Recurring Payment Cron Job

A cron job is set up to handle recurring payments, currently scheduled to run at midnight every day.

// src/app.ts
// Schedule recurring payments processing
processRecurringPaymentsTask('0 0 * * *'); // Daily at midnight

This job checks for any recurring payments that need to be processed and executes the required transactions accordingly.

Schema Definition

Here's an overview of the data relations:

• User:

  • Each User has a unique supertokensId (which mimics the SuperTokens user_id for authentication and matches the relationship data table), username, email, and password.
  • A User can have multiple PaymentAccounts.

• PaymentAccount:

  • Each PaymentAccount belongs to a User.
  • It has a unique accountNumber, accountType, and balance.
  • A PaymentAccount can have multiple, Transaction records as the sender or recipient, and RecurringPayment records as the sender or recipient.
  • The PaymentAccount entity represents accounts in the payload, distinct from userId, as it holds balance information and related data.

• Transaction:

  • Each Transaction involves a senderAccount and recipientAccount.
  • It records the amount, currency, timestamp, status, and optional address.

• RecurringPayment:

  • Each RecurringPayment involves a senderAccount and recipientAccount.
  • It records the amount, currency, interval, next payment date, and status.

Troubleshooting

Running Locally

• Ensure that PostgreSQL is installed and running on your local machine.
• Verify that the DATABASE_URL in your .env file is correctly configured for your local setup.

Using Docker

• Make sure the PostgreSQL service on your local machine is shut down before running the application in Docker. Docker will manage the PostgreSQL instance, and having two instances running simultaneously can cause conflicts.

Future Development

• Currency Conversion:
  • If transactions involve different currencies, they must be converted to the recipient's currency before processing. Future development will include support for real-time currency conversion to handle such scenarios seamlessly.