How to Secure an AI-Generated Website: A Practical Guide for Vibe Coders

You're shipping fast. Cursor is generating your API routes. v0 is spitting out beautiful components. Replit is deploying your Next.js app to production in minutes. The velocity is incredible—but somewhere in that rush, security often gets left behind.

Here's the thing: AI tools are amazing at generating functional code, but they're not security experts. They'll give you a working authentication flow, but they might forget the security headers. They'll set up your Supabase connection, but they might expose your environment variables. They'll create your API endpoints, but they might skip rate limiting.

This isn't about fear-mongering. It's about being practical. You're building real products that real people will use. A few simple security checks can save you from the kind of headaches that kill momentum.

Quick Answer: How to Secure Your AI-Generated Website

To secure an AI-generated website, focus on four critical areas: enforce HTTPS everywhere, configure security headers (CSP, HSTS, X-Frame-Options), secure your cookies with HttpOnly and Secure flags, and validate all user input. Most AI-generated code works but often misses these configuration details.

Common pitfalls include missing Content-Security-Policy headers, insecure cookie settings, exposed environment variables in client-side code, and API endpoints without rate limiting. The good news? These are all fixable with simple configuration changes, not complete rewrites.

Start by running a security scan to identify what's missing, then work through the checklist systematically. Most issues take less than 10 minutes to fix.

Core Security Risks in AI-Generated Applications

AI code generators excel at structure and functionality. They're less reliable when it comes to security configuration. Here are the specific risks you'll encounter:

Missing Security Headers

Security headers are HTTP response headers that tell browsers how to handle your site. AI tools rarely add these by default, but they're critical for preventing common attacks.

Content-Security-Policy (CSP) prevents cross-site scripting (XSS) attacks by controlling which resources can be loaded. Without it, malicious scripts injected into your site can execute freely. A basic CSP might look like: Content-Security-Policy: default-src 'self'; script-src 'self' 'unsafe-inline'.

Strict-Transport-Security (HSTS) forces browsers to use HTTPS for all future requests. This prevents man-in-the-middle attacks and ensures encrypted connections. Set it to: Strict-Transport-Security: max-age=31536000; includeSubDomains.

X-Frame-Options prevents clickjacking by blocking your site from being embedded in frames. Use X-Frame-Options: DENY or X-Frame-Options: SAMEORIGIN depending on your needs.

X-Content-Type-Options stops browsers from MIME-sniffing, which can lead to XSS vulnerabilities. Simply add: X-Content-Type-Options: nosniff.

Referrer-Policy controls how much referrer information is sent with requests. Use Referrer-Policy: strict-origin-when-cross-origin for a good balance of privacy and functionality.

Insecure Cookie Configurations

Cookies are how you maintain user sessions. Get them wrong, and attackers can hijack user accounts.

AI-generated authentication code often creates cookies without the proper security flags. Your session cookies need three things: Secure (only sent over HTTPS), HttpOnly (not accessible via JavaScript), and SameSite (prevents CSRF attacks).

In Next.js with Supabase, you might see cookies set without these flags. Check your authentication middleware and ensure cookies are configured correctly. A secure cookie looks like: Set-Cookie: session=abc123; Secure; HttpOnly; SameSite=Strict.

Exposed Environment Variables

This is a classic mistake. AI tools will generate code that uses environment variables, but they don't always distinguish between server-side and client-side usage.

In Next.js, anything prefixed with NEXT_PUBLIC_ gets exposed to the browser. If your AI assistant generated code that puts your Supabase service key in a NEXT_PUBLIC_ variable, it's visible to anyone who inspects your JavaScript bundle.

Keep sensitive keys server-side only. Use environment variables without the NEXT_PUBLIC_ prefix for API routes and server components. For client-side access, create API endpoints that proxy requests with proper authentication.

Weak Authentication Implementations

AI tools generate authentication flows that work, but they might miss important security considerations.

Common issues include missing password complexity requirements, no rate limiting on login attempts, weak session management, and missing multi-factor authentication options. While MFA might be overkill for an MVP, rate limiting is essential from day one.

If you're using Supabase Auth, you get a lot of this for free. But if your AI generated a custom auth solution, you'll need to add these protections manually.

Missing Rate Limiting

API endpoints without rate limiting are open invitations for abuse. Attackers can hammer your endpoints, causing downtime or running up your infrastructure costs.

AI-generated API routes in Next.js often skip rate limiting entirely. A simple solution is to add rate limiting middleware. For Vercel deployments, you can use their edge middleware or a library like @upstash/ratelimit.

Start with conservative limits: maybe 10 requests per minute for authentication endpoints, 100 per minute for general API calls. You can adjust based on actual usage patterns.

CORS Misconfigurations

Cross-Origin Resource Sharing (CORS) controls which domains can make requests to your API. Get it wrong, and you either block legitimate requests or allow unauthorized access.

AI tools often generate overly permissive CORS configurations like Access-Control-Allow-Origin: *, which allows any website to make requests to your API. This is fine for public APIs, but dangerous for authenticated endpoints.

For authenticated APIs, specify exact origins: Access-Control-Allow-Origin: https://yourdomain.com. Use credentials carefully: if you set Access-Control-Allow-Credentials: true, you must specify exact origins, not wildcards.

Debug Information Leakage

Development tools and error pages can leak sensitive information. AI-generated error handling might expose stack traces, database connection strings, or internal API structures.

In production, never expose detailed error messages to users. Log errors server-side with full details, but return generic messages to clients. In Next.js, use environment-based error handling: detailed errors in development, sanitized errors in production.

Check for exposed debug endpoints. Some frameworks expose /debug or /_next/webpack-hmr routes that shouldn't be accessible in production. Make sure these are disabled or protected.

Insecure API Endpoints

AI tools generate RESTful APIs quickly, but they don't always add proper authorization checks.

Every API endpoint that modifies data or returns sensitive information needs authorization. Don't trust client-side checks—verify permissions server-side. In Next.js API routes, check authentication and authorization before processing requests.

Common mistakes include endpoints that check authentication but not authorization (users can access other users' data), endpoints that trust user-provided IDs without verification, and endpoints that expose more data than necessary.

Practical Security Checklist for AI-Generated Apps

Here's a step-by-step checklist you can follow after deploying your AI-generated code:

HTTPS Enforcement

For Vercel deployments, HTTPS is automatic. For other hosts, configure redirects in your server settings or use middleware.

Security Headers Configuration

In Next.js, add these in your next.config.ts or use middleware. For Vercel, you can configure headers in vercel.json.

Cookie Security Flags

Check your authentication library's configuration. Supabase handles this automatically, but custom solutions need manual configuration.

Environment Variable Management

Run a build and inspect the generated JavaScript bundles. Search for API keys, database URLs, or other sensitive strings.

Input Validation

If you're using an ORM like Prisma or Supabase's client, you get some protection automatically. But still validate inputs for business logic constraints.

Authentication Best Practices

Supabase Auth handles most of this, but verify your implementation matches best practices.

Rate Limiting Implementation

Start conservative. You can always increase limits, but it's harder to decrease them without breaking existing integrations.

Error Handling

In Next.js, use environment variables to control error verbosity. Never expose internal error details to end users.

Common Myths About AI-Generated Code Security

Let's debunk some misconceptions that might be holding you back from proper security practices.

Myth: "AI Code is Inherently Insecure"

Reality: AI-generated code isn't inherently insecure—it's often incomplete. The code works, but it's missing security configurations that experienced developers add automatically.

The issue isn't the AI's capability; it's that security is contextual. An AI can't know your specific threat model or compliance requirements. It generates functional code, and you add the security layer.

Think of it like building a house. The AI gives you the structure and plumbing. You still need to add the locks and security system.

Myth: "My Hosting Provider Handles Security"

Reality: Security is a shared responsibility. Your hosting provider (Vercel, AWS, etc.) secures the infrastructure. You're responsible for application-level security.

They handle DDoS protection, network security, and infrastructure updates. You handle authentication, authorization, input validation, and secure coding practices.

It's like renting an apartment. The landlord maintains the building's security system, but you still need to lock your door and not leave your keys under the mat.

Myth: "I'm Too Small to Be Targeted"

Reality: Most attacks are automated. Attackers use bots to scan the entire internet for common vulnerabilities. Your size doesn't matter—your vulnerabilities do.

Automated scanners look for missing security headers, exposed endpoints, and default configurations. They don't care if you're a solo founder or a Fortune 500 company. If you're vulnerable, you'll be found.

The good news? Automated attacks are also easy to defend against. Basic security measures stop most automated threats.

How to Quickly Validate Your Website's Security

You don't need to be a security expert to check if your site has basic protections. Here's how to validate security without deep technical knowledge.

Manual Header Checks

Open your browser's developer tools, go to the Network tab, and inspect any response. Look for security headers in the response headers section. You should see Content-Security-Policy, Strict-Transport-Security, X-Frame-Options, and others.

If headers are missing, that's your first fix. Most can be added in minutes through your hosting configuration or Next.js middleware.

Cookie Inspection

In developer tools, go to the Application tab (Chrome) or Storage tab (Firefox) and check your cookies. Session cookies should have Secure and HttpOnly flags checked. If they don't, your authentication setup needs adjustment.

Environment Variable Audit

Build your Next.js app and search the generated JavaScript files for sensitive strings. If you find API keys, database URLs, or other secrets, they're exposed to users. Move them server-side immediately.

Automated Security Scanning

Manual checks are good for understanding, but automated tools are faster and more thorough. Security scanners can check dozens of configurations in seconds and provide actionable reports.

Look for tools that check security headers, TLS configuration, cookie security, and common misconfigurations. The best tools give you specific recommendations with code examples for your stack.

Getting Started with Security Validation

If you've built your site with AI tools, the fastest way to identify security gaps is to run an automated scan. These tools surface misconfigurations you might miss during manual review.

ZDELab provides free security scans that check the common issues we've discussed: missing security headers, insecure cookie configurations, TLS/SSL problems, exposed authentication endpoints, and more. It's designed for developers who want quick, actionable feedback without security expertise.

The scan checks your site's HTTP responses, analyzes security headers, validates cookie settings, tests HTTPS enforcement, and identifies potential security misconfigurations. You get a detailed report with specific findings and recommendations tailored to your tech stack.

It's not about preventing attacks—it's about surfacing risks so you can fix them. Think of it as a code review for your security configuration. Run a scan, review the findings, and work through the checklist. Most issues take minutes to fix.

Frequently Asked Questions

Is AI-generated code secure?

AI-generated code is functional but often incomplete from a security perspective. The code works, but it typically misses security configurations like headers, cookie flags, and rate limiting. These are easy to add once you know what's missing.

How do I check if my website is secure?

Start with automated security scanning tools that check for common misconfigurations. Then verify security headers are present, cookies have proper flags, environment variables aren't exposed, and API endpoints have rate limiting. Most issues are configuration problems, not code flaws.

What security headers do I need?

At minimum, you need Content-Security-Policy, Strict-Transport-Security, X-Frame-Options, X-Content-Type-Options, and Referrer-Policy. These prevent common attacks like XSS, clickjacking, and man-in-the-middle attacks. Each header serves a specific purpose and takes minutes to configure.

How do I secure cookies in Next.js?

Use the Secure, HttpOnly, and SameSite flags. In Next.js with Supabase, this is handled automatically. For custom solutions, configure your cookie settings in your authentication middleware. Never set session cookies without these flags in production.

Do I need rate limiting for my API?

Yes, especially for authentication endpoints and any endpoints that modify data. Without rate limiting, attackers can abuse your API, causing downtime or excessive costs. Start with conservative limits (10 requests per minute for auth, 100 for general APIs) and adjust based on usage.

Can I trust my hosting provider's security?

Your hosting provider secures the infrastructure, but you're responsible for application security. They handle network security and DDoS protection. You handle authentication, input validation, and secure coding practices. It's a shared responsibility model.

How often should I scan my website for security issues?

Scan after major deployments, when adding new features, and at least monthly for ongoing projects. Security isn't a one-time check—it's an ongoing process. Automated scanning makes this practical without requiring security expertise.

Start Securing Your AI-Generated Website Today

You've built something fast. Now make it secure. The good news? Most security issues in AI-generated code are configuration problems that take minutes to fix.

Start with a free security scan to identify what's missing. Then work through the checklist systematically. You don't need to be a security expert—you just need to know what to check.

Run a free security scan and get a detailed report of your site's security configuration. It takes less than a minute, and you'll have actionable recommendations within seconds.