Loan Management System

A full-stack application for managing loans, including user onboarding, loan creation, and EMI calculations.

Features

• User registration with validation (PAN, Aadhar, GSTIN, UDYAM)
• Loan creation with EMI calculations
• Loan ledger view
• CSV export of loan schedule
• Responsive UI using Material-UI

Tech Stack

• Frontend: React.js (Vite)
• Backend: Node.js, Express
• Database: MongoDB
• UI Library: Material-UI

Prerequisites

• Node.js (v14 or higher)
• MongoDB (local or Atlas URI)
• npm or yarn

Installation & Setup

1. Clone the repository

git clone https://github.com/CRYPTOcoderAS/LMS-BE

2. Backend Setup

npm install

Create a .env file in the server directory:

PORT=5000
MONGODB_URI=

Start the server:

npm start

3. Frontend Setup

cd client
npm install
npm run dev

The application will be available at http://localhost:5173

API Endpoints & Testing

1. Create User

curl -X POST http://localhost:5000/api/users \
-H "Content-Type: application/json" \
-d '{
  "name": "John Doe",
  "dob": "1990-01-01",
  "pan": "ABCDE1234F",
  "aadhaar": "123456789012",
  "gstin": "27AAPFU0939F1ZV",
  "udyam": "UDYAM-MH-02-0000001"
}'

2. Create Loan

curl -X POST http://localhost:5000/api/loans \
-H "Content-Type: application/json" \
-d '{
  "userId": "USER_ID_FROM_PREVIOUS_RESPONSE",
  "disbursementDate": "2024-03-15",
  "amount": 1000000,
  "interestRate": 12,
  "tenure": 3
}'

3. Get Loan Details

curl http://localhost:5000/api/loans/LOAN_ID

4. Download Loan Ledger

curl -O -J http://localhost:5000/api/loans/LOAN_ID/download

Data Validation Rules

PAN Format

• 5 alphabets + 4 numbers + 1 alphabet
• Example: ABCDE1234F

Aadhaar Format

• 12 digits
• Example: 123456789012

GSTIN Format

• 2 digits + 5 alphabets + 4 digits + 1 alphabet + 1 digit/alphabet + Z + 1 digit/alphabet
• Example: 27AAPFU0939F1ZV

UDYAM Format

• UDYAM-XX-DD-XXXXXXX
• Example: UDYAM-MH-02-0000001

Sample Data for Testing

User Data

{
  "name": "John Doe",
  "dob": "1990-01-01",
  "pan": "ABCDE1234F",
  "aadhaar": "123456789012",
  "gstin": "27AAPFU0939F1ZV",
  "udyam": "UDYAM-MH-02-0000001"
}

Loan Data

{
  "userId": "{userId}",
  "disbursementDate": "2024-03-15",
  "amount": 100000,
  "interestRate": 12,
  "tenure": 2
}

Error Handling

The API returns appropriate HTTP status codes:

• 200: Success
• 201: Created
• 400: Bad Request (validation errors)
• 404: Not Found
• 500: Server Error

Development

To run in development mode with hot reloading:

Backend:

npm run dev  # if nodemon is configured

Frontend:

cd client
npm run dev

Production Build

Frontend:

cd client
npm run build

The build files will be in the dist directory.

License

This project is licensed under the MIT License - see the LICENSE file for details