Environment Variables और next.config

.env                 # defaults for all environments (can be committed if no secrets)
.env.development     # only for npm run dev
.env.production      # only for next build / next start
.env.local           # YOUR secrets – overrides the above – never commit
.env.example         # template for teammates (committed, fake values)

# .env.local
DB_PASSWORD=Str0ng#Pass
SESSION_SECRET=ZmJ4b3Y5c2VjcmV0LWtleS1jaGFuZ2UtbWUtMTIzNDU2
SITE_URL=https://edusite.in
NEXT_PUBLIC_WHATSAPP=919000000000

// lib/site.js  (EduSite) — read on the server
export const site = {
  name: 'EduSite',
  url: process.env.SITE_URL || 'http://localhost:3000',
  // …
}

// lib/db.js
password: process.env.DB_PASSWORD     // undefined in the browser – safe

// components/WhatsAppButton.jsx — Client Component
'use client'
export default function WhatsAppButton() {
  const number = process.env.NEXT_PUBLIC_WHATSAPP   // replaced with "919000000000" at build
  return (
    <a href={`https://wa.me/${number}?text=Hi, I want course details`}
       target="_blank" rel="noopener" className="btn">
      💬 Chat on WhatsApp
    </a>
  )
}

// next.config.mjs  (EduSite)
/** @type {import('next').NextConfig} */
const nextConfig = {
  // Simple permanent redirects (no code needed)
  async redirects() {
    return [{ source: '/home', destination: '/', permanent: true }]
  },
  images: {
    qualities: [75, 90],          // quality values the site uses
  },
}

export default nextConfig

const nextConfig = {
  reactStrictMode: true,
  poweredByHeader: false,                      // hide "X-Powered-By: Next.js"
  trailingSlash: false,                        // /about not /about/
  output: 'standalone',                        // small server bundle for VPS/Docker
  async rewrites() {
    return [{ source: '/docs/:path*', destination: 'https://docs.example.com/:path*' }]
  },
  async headers() {
    return [{
      source: '/(.*)',
      headers: [
        { key: 'X-Content-Type-Options', value: 'nosniff' },
        { key: 'Referrer-Policy', value: 'strict-origin-when-cross-origin' },
        { key: 'Permissions-Policy', value: 'camera=(), microphone=()' },
      ],
    }]
  },
}