FinQuest Backend API

A Node.js/Express backend API for managing financial transactions with PostgreSQL database.

Features

• ✅ Add new transactions
• ✅ Retrieve transactions by user
• ✅ PostgreSQL database with Prisma ORM
• ✅ Railway deployment ready
• ✅ Input validation and error handling
• ✅ CORS enabled for frontend integration

Tech Stack

• Runtime: Node.js
• Framework: Express.js
• Database: PostgreSQL
• ORM: Prisma
• Deployment: Railway

API Endpoints

Health Check

GET /

Returns server status.

Add Transaction

POST /transactions

Request Body:

{
  "amount": 100.50,
  "type": "Grocery shopping",
  "category": "Food",
  "subcategory": "Groceries", // optional
  "comments": "Weekly grocery shopping", // optional
  "date": "2024-01-15T10:30:00Z", // optional, defaults to current date
  "userId": 1
}

Response:

{
  "message": "Transaction added successfully",
  "transaction": {
    "id": 1,
    "amount": 100.50,
    "type": "Grocery shopping",
    "category": "Food",
    "subcategory": "Groceries",
    "comments": "Weekly grocery shopping",
    "date": "2024-01-15T10:30:00Z",
    "userId": 1,
    "createdAt": "2024-01-15T10:30:00Z",
    "updatedAt": "2024-01-15T10:30:00Z"
  }
}

Get Transactions

GET /transactions?userId=1

Response:

{
  "transactions": [
    {
      "id": 1,
      "amount": 100.50,
      "type": "Grocery shopping",
      "category": "Food",
      "subcategory": "Groceries",
      "comments": "Weekly grocery shopping",
      "date": "2024-01-15T10:30:00Z",
      "userId": 1,
      "createdAt": "2024-01-15T10:30:00Z",
      "updatedAt": "2024-01-15T10:30:00Z"
    }
  ],
  "count": 1
}

Local Development

Prerequisites

• Node.js (v18 or higher)
• npm or yarn
• PostgreSQL database

Setup

1. Clone and install dependencies:

npm install

2. Set up environment variables: Create a .env file in the root directory:

DATABASE_URL="postgresql://username:password@localhost:5432/finquest"
PORT=3000
NODE_ENV=development

3. Set up the database:

# Generate Prisma client
npm run db:generate

# Push schema to database (for development)
npm run db:push

# Or run migrations (for production)
npm run db:migrate

4. Start the development server:

npm run dev

The server will start on http://localhost:3000

Railway Deployment

Prerequisites

• Railway account
• GitHub repository with this code

Deployment Steps

1. Connect to Railway:

   • Go to Railway
   • Connect your GitHub repository
   • Create a new project

2. Add PostgreSQL Database:

   • In your Railway project, click "New"
   • Select "Database" → "PostgreSQL"
   • Railway will automatically set the DATABASE_URL environment variable

3. Deploy the Application:

   • Railway will automatically detect the Node.js app
   • The start script in package.json will be used
   • Railway will install dependencies and start the server

4. Set up the Database:

   • After deployment, run database migrations:

   # Connect to Railway shell or use Railway CLI
   npx prisma db push

Environment Variables for Railway

Railway will automatically set:

• DATABASE_URL (from PostgreSQL service)
• PORT (Railway sets this automatically)

Custom Domain (Optional)

• In Railway dashboard, go to your service
• Click "Settings" → "Domains"
• Add your custom domain

Testing the API

Using curl

Health Check:

curl http://localhost:3000/

Add Transaction:

curl -X POST http://localhost:3000/transactions \
  -H "Content-Type: application/json" \
  -d '{
    "amount": 100.50,
    "type": "Grocery shopping",
    "category": "Food",
    "subcategory": "Groceries",
    "comments": "Weekly grocery shopping",
    "userId": 1
  }'

Get Transactions:

curl "http://localhost:3000/transactions?userId=1"

Using Postman or similar tools

Import these requests:

1. Health Check:

   • Method: GET
   • URL: http://localhost:3000/

2. Add Transaction:

   • Method: POST
   • URL: http://localhost:3000/transactions
   • Headers: Content-Type: application/json
   • Body (raw JSON):

   {
     "amount": 100.50,
     "type": "Grocery shopping",
     "category": "Food",
     "subcategory": "Groceries",
     "comments": "Weekly grocery shopping",
     "userId": 1
   }

3. Get Transactions:

   • Method: GET
   • URL: http://localhost:3000/transactions?userId=1

Database Schema

The Transaction model includes:

• id: Auto-incrementing primary key
• amount: Decimal field for transaction amount
• type: Text description of the transaction
• category: Transaction category (e.g., Food, Transport, etc.)
• subcategory: Optional subcategory for more detailed classification
• comments: Optional additional notes or comments
• date: Transaction date (defaults to current date)
• userId: User identifier (for future user system)
• createdAt: Timestamp when record was created
• updatedAt: Timestamp when record was last updated

Error Handling

The API includes comprehensive error handling:

• 400 Bad Request: Missing required fields or invalid data
• 500 Internal Server Error: Database or server errors

All errors return JSON responses with error details.

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Test thoroughly
5. Submit a pull request

License

ISC License