Koins Wallet API

A professional-grade fintech backend application for wallet management, featuring secure transactions, real-time notifications via RabbitMQ, and seamless payment integration with Paystack.

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Getting Started

Prerequisites

Ensure you have the following installed:

• Java 21 (LTS)
• Maven 3.9+
• Docker & Docker Compose (Recommended for infrastructure)
• PostgreSQL 15+
• RabbitMQ

Setup Instructions

1. Clone the Repository

git clone <repository-url>
cd wallet

2. Infrastructure Setup (Recommended)

The easiest way to start the required services (PostgreSQL & RabbitMQ) is using Docker:

docker-compose up -d postgres rabbitmq

3. Configure Environment Variables

Create a .env file in the root directory with the following configurations:

# Database
DB_URL=<your-database-url>
DB_USERNAME=<your-database-username>
DB_PASSWORD=<your-database-password>

# Security
JWT_SECRET=<your-jwt-secret>
JWT_EXPIRATION=<token-expiration-ms>

# Mail
MAIL_HOST=<smtp-host>
MAIL_PORT=<smtp-port>
MAIL_USERNAME=<smtp-username>
MAIL_PASSWORD=<smtp-password>

# Paystack
PAYSTACK_SECRET_KEY=<your-paystack-secret-key>

4. Run the Application

./mvnw spring-boot:run

The server will start at http://localhost:8080.

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Database Configuration

The application uses PostgreSQL as its primary data store.

• Database Name: koins_db
• Dialect: PostgreSQLDialect
• Hibernate Strategy: update (auto-creates tables on startup)

To manually set up the database:

1. Create the database.
2. Update the DB_URL in your .env or application.yml.

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Environment Variables

Variable	Description
DB_URL	PostgreSQL Connection URL
DB_USERNAME	Database Username
DB_PASSWORD	Database Password
JWT_SECRET	Secret key for JWT signing
JWT_EXPIRATION	JWT Token validity (ms)
MAIL_HOST	SMTP Server Host
MAIL_PORT	SMTP Server Port
MAIL_USERNAME	SMTP Username
MAIL_PASSWORD	SMTP App Password
PAYSTACK_SECRET_KEY	Paystack Secret API Key

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API Documentation

Interactive API documentation is provided via Swagger UI. Once the application is running, you can access it at:

Swagger UI

You can also download the raw OpenAPI specification:

• JSON: http://localhost:8080/v3/api-docs

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Tech Stack

• Framework: Spring Boot 3.4.3
• Language: Java 21
• Security: Spring Security & JWT
• Messaging: RabbitMQ
• Database: PostgreSQL / Spring Data JPA
• API Docs: SpringDoc OpenAPI
• Integrations: Paystack API