NeoFinTech (MERN Boot Sprint 01)

Author: Paul Sattaur
Stack: MongoDB, Express, React, Node.js

A full-stack fintech demo app built as part of the MERN Boot Sprint. This repository contains both the backend (Express + Mongoose) and frontend (React + Vite) codebases.

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🏃 Running Locally

# Backend
cd backend
npm install
npm run dev

API runs at: http://localhost:5000
Frontend (coming soon) runs at: http://localhost:5173

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⚙️ Environment Variables

Create a .env file in /backend with:

PORT=5000
MONGO_URI=mongodb://localhost:27017/NeoFinTech
JWT_SECRET=superscretkey

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🧠 API Documentation

Base URL

http://localhost:5000/api

Endpoints Overview

👤 User Routes

Method	Endpoint	Description	Body Example
POST	/users/register	Registers a new user	{ "name": "Paul", "email": "paul@example.com", "password": "secret123" }
GET	/users	Returns all users	N/A

💳 Transaction Routes

Method	Endpoint	Description	Body Example
POST	/transactions	Creates a new transaction	{ "userId": "ObjectId_of_User", "type": "credit", "amount": 250, "category": "Salary" }
GET	/transactions	Lists all transactions	N/A

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⚙️ Validation Rules

• userId → must be a valid ObjectId referencing an existing user.
• type → "credit" or "debit".
• amount → must be a positive number.
• category → required string.
• Server will respond with 400 Bad Request for invalid or missing fields.

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🧩 Error Handling

All routes use centralized middleware for error reporting:

app.use((err, req, res, next) => {
  console.error("Error:", err.message);
  res.status(500).json({ error: err.message });
});

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🧪 Testing with Postman

1. Start backend:

   cd backend
   npm run dev

2. In Postman:

   • Register User → POST → http://localhost:5000/api/users/register
   • List Users → GET → http://localhost:5000/api/users
   • Add Transaction → POST → http://localhost:5000/api/transactions
   • List Transactions → GET → http://localhost:5000/api/transactions

3. Verify saved data using MongoDB Compass at NeoFinTech.users and NeoFinTech.transactions.