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Environment Variables Reference

All configuration is managed through environment variables defined in a .env file.

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Server Configuration

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PORT

The port number where the Express server will listen. 
PORT=3005
  • Type: Number
  • Default: 3005 (src/index.ts:4)
  • Required: No

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Database Configuration

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DATABASE_URL

PostgreSQL connection string used by Sequelize ORM. 
DATABASE_URL=postgresql://username:password@host:port/database
  • Type: String (PostgreSQL connection URI)
  • Required: Yes
  • Used in: src/config/db.ts:5
  • Format: postgresql://[user]:[password]@[host]:[port]/[database]
DATABASE_URL=postgresql://cognit_user:password@localhost:5432/cognit_dev
Never commit your DATABASE_URL to version control. This contains sensitive credentials.

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JWT Authentication

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JWT_SECRET

Secret key used to sign and verify JSON Web Tokens for user authentication. 
JWT_SECRET=your-super-secret-key-minimum-32-characters-recommended
  • Type: String
  • Required: Yes
  • Used in:
    • src/utils/jwt.ts:4 - Token generation
    • src/middleware/auth.ts:31 - Token verification
  • Token Expiration: 30 days (src/utils/jwt.ts:5)
Generate a secure random string for production:
node -e "console.log(require('crypto').randomBytes(32).toString('hex'))"

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Email Configuration (Nodemailer)

The application uses Nodemailer for sending emails (account confirmation, password reset, etc.).

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EMAIL_HOST

SMTP server hostname. 
EMAIL_HOST=smtp.gmail.com
  • Type: String
  • Required: Yes
  • Used in: src/config/nodemailer.ts:16

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EMAIL_PORT

SMTP server port number. 
EMAIL_PORT=587
  • Type: Number
  • Required: Yes
  • Used in: src/config/nodemailer.ts:17
  • Common values:
    • 587 - TLS/STARTTLS (recommended)
    • 465 - SSL
    • 25 - Unencrypted (not recommended)

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EMAIL_USER

SMTP authentication username (usually your email address). 
EMAIL_USER=your-email@gmail.com
  • Type: String
  • Required: Yes
  • Used in: src/config/nodemailer.ts:19

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EMAIL_PASS

SMTP authentication password or app-specific password. 
EMAIL_PASS=your-app-specific-password
  • Type: String
  • Required: Yes
  • Used in: src/config/nodemailer.ts:20
For Gmail, you must use an App Password, not your regular password.
EMAIL_HOST=smtp.gmail.com
EMAIL_PORT=587
EMAIL_USER=your-email@gmail.com
EMAIL_PASS=app-specific-password

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FRONTEND_URL

The URL of your frontend application, used in email links and CORS configuration. 
FRONTEND_URL=http://localhost:5175
  • Type: String (URL)
  • Required: Yes
  • Used in: Email templates for confirmation and password reset links

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CORS Configuration

Cross-Origin Resource Sharing (CORS) is configured in src/server.ts.

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Current Configuration

app.use(cors({
    origin: ['https://cognit.website', 'http://localhost:5175'],
    credentials: true,
}));
Source: src/server.ts:27-30

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Configuration Options

OptionValueDescription
originArray of URLsAllowed origins for cross-origin requests
credentialstrueAllows cookies and authentication headers

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Customizing CORS

To allow additional origins, modify the origin array: 
app.use(cors({
    origin: [
        'https://cognit.website',
        'https://app.cognit.website',
        'http://localhost:5175',
        'http://localhost:3000'
    ],
    credentials: true,
}));
Never use origin: '*' with credentials: true - browsers will reject the requests for security reasons.

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Dynamic CORS (Environment-based)

For better flexibility, use environment variables: 
const allowedOrigins = process.env.FRONTEND_URL 
  ? [process.env.FRONTEND_URL, 'https://cognit.website']
  : ['http://localhost:5175'];

app.use(cors({
    origin: allowedOrigins,
    credentials: true,
}));

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Rate Limiting Configuration

Rate limiting prevents abuse by limiting the number of requests from a single IP.

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Current Configuration

import { rateLimit } from 'express-rate-limit'

export const limiter = rateLimit({
    windowMs: 60 * 1000,      // 1 minute
    limit: 5,                  // 5 requests per window
    message: {"error": "Max limit requests"}
})
Source: src/config/limiter.ts:1-7

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Configuration Options

OptionValueDescription
windowMs60000 (1 minute)Time window for rate limiting
limit5Maximum requests per window
messageCustom JSONResponse when limit exceeded

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Where It’s Applied

The rate limiter is currently applied to all authentication routes: 
router.use(limiter)  // src/routes/authRouter.ts:10
This means all /api/auth/* endpoints are limited to 5 requests per minute.

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Customizing Rate Limits

export const limiter = rateLimit({
    windowMs: 15 * 60 * 1000,  // 15 minutes
    limit: 100,                 // 100 requests per 15 min
    message: {"error": "Too many requests, please try again later"}
})
Consider different rate limits for different endpoint types:
  • Authentication (login, register): Strict (5-10 req/15min)
  • Read operations: Moderate (100 req/15min)
  • Write operations: Moderate (50 req/15min)

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Database Connection Configuration

Sequelize ORM manages the database connection.

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Current Configuration

import { Sequelize } from "sequelize-typescript";
import dotenv from 'dotenv'
dotenv.config()

export const db = new Sequelize(process.env.DATABASE_URL, {
    models: [__dirname + '/../models/**/*'],
    logging: false
})
Source: src/config/db.ts:1-8

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Configuration Options

OptionValueDescription
Connection Stringprocess.env.DATABASE_URLPostgreSQL connection URI
models[__dirname + '/../models/**/*']Path to model files
loggingfalseDisable SQL query logging

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Enable SQL Logging (Development)

For debugging, enable SQL query logging: 
export const db = new Sequelize(process.env.DATABASE_URL, {
    models: [__dirname + '/../models/**/*'],
    logging: process.env.NODE_ENV === 'development' ? console.log : false
})

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Connection Pool Configuration

For production, configure connection pooling: 
export const db = new Sequelize(process.env.DATABASE_URL, {
    models: [__dirname + '/../models/**/*'],
    logging: false,
    pool: {
        max: 10,        // Maximum connections
        min: 2,         // Minimum connections
        acquire: 30000, // Max time to get connection (ms)
        idle: 10000     // Max idle time before release (ms)
    }
})

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Security Configuration

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Helmet (Security Headers)

Helmet sets various HTTP headers for security. 
app.use(helmet());
Source: src/server.ts:26 Helmet automatically enables:
  • Content-Security-Policy
  • X-DNS-Prefetch-Control
  • X-Frame-Options
  • X-Content-Type-Options
  • And more…

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Authentication Middleware

JWT authentication is handled by the authenticate middleware: 
export const authenticate = async (req: Request, res: Response, next: NextFunction) => {
    const bearer = req.headers.authorization
    // Validates Bearer token format
    // Verifies JWT with JWT_SECRET
    // Attaches user to request object
}
Source: src/middleware/auth.ts:14-42 Protected routes use this middleware: 
router.get("/user", authenticate, AuthController.getUserAuthenticated)

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Complete Configuration Example

# Server
PORT=3005
NODE_ENV=development

# Database
DATABASE_URL=postgresql://cognit_user:secure_password@localhost:5432/cognit_dev

# Authentication
JWT_SECRET=a1b2c3d4e5f6g7h8i9j0k1l2m3n4o5p6q7r8s9t0u1v2w3x4y5z6

# Email
EMAIL_HOST=smtp.gmail.com
EMAIL_PORT=587
EMAIL_USER=cognit@gmail.com
EMAIL_PASS=app-specific-password-here

# Frontend
FRONTEND_URL=http://localhost:5175

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Next Steps

Deployment

Learn how to deploy to production

API Reference

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