Loan Management API

Description:

This Loan Management API handles loan applications, repayment schedules, and tracking for users. The API provides secure authentication via JWT, allows users to manage their loans, and enables administrators to oversee transactions. The project demonstrates expertise in API development, authentication, database design, and follows best practices for scalability, security, and maintainability.

Technologies Used:

• Django REST Framework (DRF): For building the API endpoints
• PostgreSQL: As the primary relational database
• JWT Authentication: For securing API endpoints with token-based auth
• Swagger & OpenAPI: For API documentation and visualization
• Python-dateutil: For advanced date manipulation
• Django-environ: For environment variable management
• Django CORS headers: For cross-origin resource sharing

Key Features:

1. JWT Authentication: Secure endpoints with access and refresh tokens
2. User Management: Register, login, and profile management
3. Loan Application & Lifecycle: Apply, approve/reject, and track loans
4. Repayment Schedule: Automatic generation of payment schedules with interest calculation
5. Loan Repayment Tracking: Process payments and update loan balances
6. Role-Based Access Control: Different permissions for regular users and admins
7. CORS Support: Cross-origin resource sharing for frontend integration

API Endpoints

Authentication

• POST /api/auth/register/: Register a new user
• POST /api/auth/login/: User login with JWT token response
• POST /api/auth/logout/: Logout and blacklist user token
• POST /api/token/refresh/: Refresh an expired access token
• GET /api/auth/user/: Get authenticated user's profile

Loans

• GET /api/loans/: List all loans for the authenticated user
• POST /api/loans/: Apply for a new loan
• GET /api/loans/{loan_id}/: Get details of a specific loan
• GET /api/loans/{loan_id}/approve/: Approve a loan (admin function)
• GET /api/loans/{loan_id}/reject/: Reject a loan (admin function)
• GET /api/loans/{loan_id}/schedule/: Get the repayment schedule for a loan

Repayments

• POST /api/repayments/{loan_id}/: Make a repayment towards a loan

Setup and Installation

Prerequisites

• Python 3.8+
• PostgreSQL database
• Git

Running with Docker

Ensure you have Docker installed, if not follow their installation guide Docker Installation

1. Build Docker Image:

docker build -t loan-service .

2. Run Docker Image:

The project will run at localhost:8000, add the -d tag to run in the background.

docker run --name loan-service -p 8000:8000 loan-service

3. View all running images

docker ps

4. Add an admin password

docker exec -it loan-service python manage.py changepassword admin

Access the admin page at http://127.0.0.1:8000/admin or localhost:8000/admin

• username: admin
• password: (Your set password from the above command)

5. Stop Docker Image:

docker stop loan-service

Manual Setup

1. Clone the Repository

git clone https://github.com/BlacAc3/loan-api.git
cd loan-api

2. Set Up Virtual Environment

python -m venv venv
source venv/bin/activate   # On Windows: venv\Scripts\activate

3. Install Dependencies

pip install -r requirements.txt

4. Create Environment File

Create a .env file with the following variables:

SECRET_KEY=your_secret_key
DATABASE_URL=postgres://username:password@localhost:5432/loan_db

5. Run Migrations

python manage.py migrate

6. Create a Superuser (Admin)

python manage.py createsuperuser

7. Run the Development Server

python manage.py runserver

Access the API at http://127.0.0.1:8000/ or localhost:8000.

Running Tests

python manage.py test

API Documentation

For detailed API documentation, please refer to:

• OpenAPI YAML file
• SwaggerHub API Visualization

License

This project is licensed under the MIT License. See the LICENSE file for details.