💰 Expense Management API

A robust and secure API for managing personal expenses, built with Node.js, Express.js, and TypeScript. This project provides a full suite of features, including user authentication, CRUD operations for expenses, and advanced filtering capabilities.

🚀 Features

• User Authentication: Secure user registration and login using JWT (JSON Web Tokens).
• User Profile: Retrieve user details via a protected route.
• Expense Management: Full CRUD (Create, Read, Update, Delete) functionality for expenses.
• Expense Filtering: Easily filter expenses by specific time periods: last week, last month, last quarter, and a custom date range.
• Database: Uses Prisma ORM with PostgreSQL (NeonDB) for a type-safe and efficient data layer.
• Category Seeding: Automatically seeds a predefined list of expense categories into the database upon server startup.

🛠️ Tech Stack

• Backend: Node.js, Express.js, TypeScript
• Database: PostgreSQL (NeonDB) with Prisma ORM
• Authentication: JWT
• Package Manager: Yarn

💻 Setup and Installation

1. Clone the repository:

git clone https://github.com/Dipit12/Expense-TrackerAPI-Backend-Assignment.git

2. Install dependencies:

yarn install

3. Environment Variables:

Create a .env file in the root directory and add the following variables. Replace the placeholder values with your actual database connection string and a strong JWT secret.

PORT = "the port where you want to run the application"
DATABASE_URL="your_database_connection_string"
SALT_KEY="your_very_strong_secret"

4. Run Prisma Migrations:

To set up your database schema, run the following command:

npx prisma migrate dev

5. Start the server:

yarn dev

The API will now be running at http://localhost:3000 (or your configured port).

🗺️ API Endpoints

All endpoints are prefixed with /api/v1.

➡️ Health Check

• GET /api/v1/healthCheck
  • Description: Checks if the API is up and running.
  • Response: API is up and running

➡️ Authentication

• POST /api/v1/auth/signup

  • Description: Registers a new user.
  • Body: { "userName":"user name","email": "user@example.com", "password": "password123" }

• POST /api/v1/auth/login

  • Description: Authenticates a user and returns a JWT token.
  • Body: { "email": "user@example.com", "password": "password123" }

• GET /api/v1/auth/profile

  • Description: Retrieves the authenticated user's profile. This is a protected route.
  • Headers: Authorization: Bearer <JWT_token>

➡️ Expense Management

All expense management routes require a JWT token in the Authorization header.

• POST /api/v1/expenses

  • Description: Adds a new expense for the authenticated user.
  • Headers: Authorization: Bearer <JWT_token>
  • Body: { "amount": 50.75, "description": "Coffee", "date": "2025-09-18", "categoryId": 1 }

• GET /api/v1/expenses

  • Description: Retrieves all expenses for the authenticated user.
  • Headers: Authorization: Bearer <JWT_token>

• GET /api/v1/expenses/:id

  • Description: Retrieves a specific expense by ID.
  • Headers: Authorization: Bearer <JWT_token>
  • URL Param: :id (ID of the expense)

• PUT /api/v1/expenses/:id

  • Description: Updates an existing expense.
  • Headers: Authorization: Bearer <JWT_token>
  • URL Param: :id (ID of the expense)
  • Body: { "amount": 60.50 } (partial update)

• DELETE /api/v1/expenses/:id

  • Description: Deletes an expense.
  • Headers: Authorization: Bearer <JWT_token>
  • URL Param: :id (ID of the expense)

➡️ Expense Filtering

These routes also require a JWT token.

• GET /api/v1/expenses/filter/week

  • Description: Retrieves all expenses from the last 7 days.
  • Headers: Authorization: Bearer <JWT_token>

• GET /api/v1/expenses/filter/month

  • Description: Retrieves all expenses from the last 30 days.
  • Headers: Authorization: Bearer <JWT_token>

• GET /api/v1/expenses/filter/quarter

  • Description: Retrieves all expenses from the last 90 days.
  • Headers: Authorization: Bearer <JWT_token>

• GET /api/v1/expenses/filter/custom

  • Description: Retrieves expenses within a custom date range.
  • Headers: Authorization: Bearer <JWT_token>
  • Query Params: ?startDate=YYYY-MM-DD&endDate=YYYY-MM-DD
  • Example: /api/v1/expenses/filter/custom?startDate=2025-09-01&endDate=2025-09-30