Expense Tracker Backend

Backend API for the Expense Tracker application. This service handles user authentication, profile management, expenses, incomes, budgets, and MongoDB persistence for the frontend app.

Frontend repository: https://github.com/devMonkRahul/Expense-Tracker-Frontend

Features

• User registration and login
• JWT-based protected routes
• Profile fetch and profile update endpoints
• Income CRUD with date-based filtering and pagination
• Expense CRUD with date-based filtering and pagination
• Budget CRUD
• MongoDB persistence with Mongoose
• Security middleware with helmet, cors, and request logging via morgan

Tech Stack

• Node.js
• Express.js
• MongoDB
• Mongoose
• JWT Authentication
• Docker and Docker Compose

Project Structure

.
├── app.js
├── Dockerfile
├── docker-compose.yaml
├── server
│   ├── config
│   ├── constants.js
│   ├── controllers
│   ├── middlewares
│   ├── models
│   ├── routes
│   └── utils
└── logs

API Overview

Base URL: http://localhost:4000

Health and Logs

• GET / - Server health check
• GET /logs - Returns the last 100 access log lines

User Routes

• POST /api/v1/user/register
• POST /api/v1/user/login
• GET /api/v1/user/profile
• PATCH /api/v1/user/profile/update
• PATCH /api/v1/user/profile/changePassword
• GET /api/v1/user/validate/username/:username
• GET /api/v1/user/validate/email/:email

Transaction Routes

• POST /api/v1/transaction/addIncome
• GET /api/v1/transaction/getIncomes
• PATCH /api/v1/transaction/editIncome/:incomeId
• DELETE /api/v1/transaction/deleteIncome/:incomeId
• POST /api/v1/transaction/addExpense
• GET /api/v1/transaction/getExpenses
• PATCH /api/v1/transaction/editExpense/:expenseId
• DELETE /api/v1/transaction/deleteExpense/:expenseId

Budget Routes

• POST /api/v1/budget/addBudget
• GET /api/v1/budget/getBudgets
• GET /api/v1/budget/getBudget/:budgetId
• PATCH /api/v1/budget/updateBudget/:budgetId
• DELETE /api/v1/budget/deleteBudget/:budgetId

Most application routes require an Authorization header in the format Bearer <token>.

Environment Variables

Create a .env file in the project root. You can copy the example file:

cp .env.example .env

Required variables:

PORT=4000
MONGODB_URI=mongodb://localhost:27017/expense-tracker
ACCESS_TOKEN_SECRET=replace-with-a-strong-secret
ACCESS_TOKEN_EXPIRY=1d

Run Locally

Prerequisites

• Node.js 20 or newer
• npm
• MongoDB running locally or a MongoDB Atlas connection string

Setup

1. Clone the repository:

git clone https://github.com/devMonkRahul/Expense-Tracker-Backend.git
cd Expense-Tracker-Backend

2. Install dependencies:

npm install

3. Create your environment file:

cp .env.example .env

4. Update MONGODB_URI and ACCESS_TOKEN_SECRET in .env.

5. Start the development server:

npm run dev

The API will be available at http://localhost:4000.

Run With Docker

Using Docker Compose

This project includes a docker-compose.yaml that starts:

• mongodb on port 27017
• expense-tracker-backend on port 4000

Run:

docker compose up --build

To stop the services:

docker compose down

To stop and remove the MongoDB volume as well:

docker compose down -v

Using Docker Only

Build the image:

docker build -t expense-tracker-backend .

Run the container:

docker run -p 4000:4000 \
  -e PORT=4000 \
  -e MONGODB_URI=mongodb://host.docker.internal:27017/expense-tracker \
  -e ACCESS_TOKEN_SECRET=replace-with-a-strong-secret \
  -e ACCESS_TOKEN_EXPIRY=1d \
  expense-tracker-backend

If you are running Docker on Linux and host.docker.internal is unavailable, replace it with a reachable MongoDB host or use Docker Compose.

Frontend Integration

Frontend repository: https://github.com/devMonkRahul/Expense-Tracker-Frontend

For local integration:

• Start this backend on http://localhost:4000
• Start the frontend separately
• Point the frontend API configuration to this backend URL

The backend CORS configuration already allows:

• http://localhost:5173
• http://localhost:5174
• https://expense-tracker.therahul.xyz
• https://expense-tracker-mu-wheat.vercel.app

Scripts

• npm run dev - Start the app with nodemon
• npm start - Start the app in production mode

Notes

• Access logs are written to logs/access.log
• The Docker image runs the app as a non-root user
• Docker Compose uses a MongoDB named volume for persistence