Securing Your Next.js Application

Security should never be an afterthought. In this guide, we'll cover everything you need to know about securing your Next.js application.

Authentication with NextAuth.js

NextAuth.js provides a complete authentication solution:

``typescript
import NextAuth from "next-auth"
import GithubProvider from "next-auth/providers/github"

export default NextAuth({
providers: [
GithubProvider({
clientId: process.env.GITHUB_ID,
clientSecret: process.env.GITHUB_SECRET,
}),
],
})
`

API Route Protection

Always validate and sanitize input in your API routes:

`typescript
export async function POST(req: Request) {
const body = await req.json()

// Validate input with Zod
const parsed = schema.safeParse(body)
if (!parsed.success) {
return Response.json({ error: "Invalid input" }, { status: 400 })
}

// Process request...
}
`

Security Headers

Configure security headers in next.config.js:

`javascript
const securityHeaders = [
{ key: "X-Frame-Options", value: "DENY" },
{ key: "X-Content-Type-Options", value: "nosniff" },
{ key: "Referrer-Policy", value: "origin-when-cross-origin" },
]
``

Best Practices

1. Never expose sensitive data in client-side code
2. Use environment variables for secrets
3. Implement rate limiting
4. Enable CORS properly
5. Regular security audits

Conclusion

Security is a continuous process. Stay updated with the latest best practices!