Node.js Example

import { defineEnv, z } from 'nviron';

export const env = defineEnv({
  // Server Configuration
  NODE_ENV: z.enum(['development', 'production', 'test']),
  PORT: z.coerce.number().int().positive().default(3000),
  HOST: z.string().default('0.0.0.0'),
  
  // Database
  DATABASE_URL: z.string().url().startsWith('postgresql://'),
  DATABASE_POOL_MIN: z.coerce.number().int().min(0).default(2),
  DATABASE_POOL_MAX: z.coerce.number().int().min(1).default(10),
  
  // Redis
  REDIS_HOST: z.string().default('localhost'),
  REDIS_PORT: z.coerce.number().int().default(6379),
  REDIS_PASSWORD: z.string().optional(),
  
  // Security
  JWT_SECRET: z.string().min(32),
  JWT_EXPIRES_IN: z.string().default('7d'),
  SESSION_SECRET: z.string().min(32),
  BCRYPT_ROUNDS: z.coerce.number().int().min(10).max(15).default(12),
  
  // CORS
  CORS_ORIGIN: z.string().transform((val) => val.split(',')),
  CORS_CREDENTIALS: z.coerce.boolean().default(true),
  
  // Rate Limiting
  RATE_LIMIT_WINDOW_MS: z.coerce.number().default(900000), // 15 minutes
  RATE_LIMIT_MAX_REQUESTS: z.coerce.number().default(100),
  
  // External APIs
  SENDGRID_API_KEY: z.string().startsWith('SG.'),
  AWS_ACCESS_KEY_ID: z.string().length(20),
  AWS_SECRET_ACCESS_KEY: z.string().length(40),
  AWS_REGION: z.string().default('us-east-1'),
  AWS_S3_BUCKET: z.string(),
  
  // Logging
  LOG_LEVEL: z.enum(['debug', 'info', 'warn', 'error']).default('info'),
  LOG_FORMAT: z.enum(['json', 'pretty']).default('json'),
});

import express from 'express';
import cors from 'cors';
import { env } from './env';

const app = express();

// CORS configuration
app.use(cors({
  origin: env.CORS_ORIGIN,
  credentials: env.CORS_CREDENTIALS,
}));

app.use(express.json());

// Health check
app.get('/health', (req, res) => {
  res.json({
    status: 'ok',
    environment: env.NODE_ENV,
    timestamp: new Date().toISOString(),
  });
});

// Start server
app.listen(env.PORT, env.HOST, () => {
  console.log(`🚀 Server running on ${env.HOST}:${env.PORT}`);
  console.log(`📊 Environment: ${env.NODE_ENV}`);
  console.log(`💾 Database: ${env.DATABASE_URL.split('@')[1]}`);
});

# Server
NODE_ENV=development
PORT=3000
HOST=0.0.0.0

# Database
DATABASE_URL=postgresql://user:password@localhost:5432/mydb
DATABASE_POOL_MIN=2
DATABASE_POOL_MAX=10

# Redis
REDIS_HOST=localhost
REDIS_PORT=6379
REDIS_PASSWORD=

# Security
JWT_SECRET=your-jwt-secret-min-32-characters-long
JWT_EXPIRES_IN=7d
SESSION_SECRET=your-session-secret-min-32-characters
BCRYPT_ROUNDS=12

# CORS
CORS_ORIGIN=http://localhost:3000,http://localhost:5173
CORS_CREDENTIALS=true

# Rate Limiting
RATE_LIMIT_WINDOW_MS=900000
RATE_LIMIT_MAX_REQUESTS=100

# External APIs
SENDGRID_API_KEY=SG.your-sendgrid-api-key
AWS_ACCESS_KEY_ID=AKIAIOSFODNN7EXAMPLE
AWS_SECRET_ACCESS_KEY=wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY
AWS_REGION=us-east-1
AWS_S3_BUCKET=my-s3-bucket

# Logging
LOG_LEVEL=info
LOG_FORMAT=json