Next.js Supabase V3 (#463)

Version 3 of the kit:
- Radix UI replaced with Base UI (using the Shadcn UI patterns)
- next-intl replaces react-i18next
- enhanceAction deprecated; usage moved to next-safe-action
- main layout now wrapped with [locale] path segment
- Teams only mode
- Layout updates
- Zod v4
- Next.js 16.2
- Typescript 6
- All other dependencies updated
- Removed deprecated Edge CSRF
- Dynamic Github Action runner

docs/development/external-marketing-website.mdoc

@@ -0,0 +1,210 @@
+---
+status: "published"
+label: "External Marketing Website"
+title: "External Marketing Website in the Next.js Supabase Turbo Starter Kit"
+description: "Configure Makerkit to redirect marketing pages to an external website built with Framer, Webflow, or WordPress."
+order: 9
+---
+
+Redirect Makerkit's marketing pages to an external website by configuring the `proxy.ts` middleware. This lets you use Framer, Webflow, or WordPress for your marketing site while keeping Makerkit for your SaaS application.
+
+{% sequence title="External Marketing Website Setup" description="Configure redirects to your external marketing site" %}
+
+[Understand the architecture](#when-to-use-an-external-marketing-website)
+
+[Configure the middleware](#configuring-the-middleware)
+
+[Handle subpaths and assets](#handling-subpaths-and-assets)
+
+[Verify the redirects](#verify-the-redirects)
+
+{% /sequence %}
+
+## When to Use an External Marketing Website
+
+Use an external marketing website when:
+
+- **Marketing team independence**: Your marketing team needs to update content without developer involvement
+- **Design flexibility**: You want visual builders like Framer or Webflow for landing pages
+- **Content management**: WordPress or a headless CMS better fits your content workflow
+- **A/B testing**: Your marketing tools integrate better with external platforms
+
+Keep marketing pages in Makerkit when:
+
+- You want a unified codebase and deployment
+- Your team is comfortable with React and Tailwind
+- You need tight integration between marketing and app features
+
+## Configuring the Middleware
+
+{% alert type="default" title="Next.js 16+" %}
+In Next.js 16+, Makerkit uses `proxy.ts` for middleware. Prior versions used `middleware.ts`.
+{% /alert %}
+
+Edit `apps/web/proxy.ts` to redirect marketing pages:
+
+```typescript {% title="apps/web/proxy.ts" %}
+import type { NextRequest } from 'next/server';
+import { NextResponse } from 'next/server';
+
+const EXTERNAL_MARKETING_URL = 'https://your-marketing-site.com';
+
+const MARKETING_PAGES = [
+  '/',
+  '/pricing',
+  '/faq',
+  '/contact',
+  '/about',
+  '/blog',
+  '/privacy-policy',
+  '/terms-of-service',
+  '/cookie-policy',
+];
+
+export function proxy(req: NextRequest) {
+  if (isMarketingPage(req)) {
+    const redirectUrl = new URL(
+      req.nextUrl.pathname,
+      EXTERNAL_MARKETING_URL
+    );
+
+    // Preserve query parameters
+    redirectUrl.search = req.nextUrl.search;
+
+    return NextResponse.redirect(redirectUrl, { status: 301 });
+  }
+
+  // Continue with existing middleware logic
+  return NextResponse.next();
+}
+
+function isMarketingPage(req: NextRequest): boolean {
+  const pathname = req.nextUrl.pathname;
+
+  return MARKETING_PAGES.some((page) => {
+    if (page === '/') {
+      return pathname === '/';
+    }
+    return pathname === page || pathname.startsWith(`${page}/`);
+  });
+}
+```
+
+### Configuration Options
+
+| Option | Description |
+|--------|-------------|
+| `EXTERNAL_MARKETING_URL` | Your external marketing site's base URL |
+| `MARKETING_PAGES` | Array of paths to redirect |
+| Status code `301` | Permanent redirect (SEO-friendly) |
+| Status code `302` | Temporary redirect (for testing) |
+
+## Handling Subpaths and Assets
+
+### Blog Posts with Dynamic Paths
+
+If your blog uses dynamic paths like `/blog/post-slug`, handle them separately:
+
+```typescript
+const MARKETING_PAGES = [
+  // ... other pages
+];
+
+const MARKETING_PREFIXES = [
+  '/blog',
+  '/resources',
+  '/case-studies',
+];
+
+function isMarketingPage(req: NextRequest): boolean {
+  const pathname = req.nextUrl.pathname;
+
+  // Check exact matches
+  if (MARKETING_PAGES.includes(pathname)) {
+    return true;
+  }
+
+  // Check prefix matches
+  return MARKETING_PREFIXES.some((prefix) =>
+    pathname.startsWith(prefix)
+  );
+}
+```
+
+### Excluding Application Routes
+
+Keep certain routes in Makerkit even if they share a marketing prefix:
+
+```typescript
+const APP_ROUTES = [
+  '/blog/admin',  // Blog admin panel stays in Makerkit
+  '/pricing/checkout',  // Checkout flow stays in Makerkit
+];
+
+function isMarketingPage(req: NextRequest): boolean {
+  const pathname = req.nextUrl.pathname;
+
+  // Never redirect app routes
+  if (APP_ROUTES.some((route) => pathname.startsWith(route))) {
+    return false;
+  }
+
+  // ... rest of the logic
+}
+```
+
+## Verify the Redirects
+
+After configuring, verify redirects work correctly:
+
+```bash
+# Start the development server
+pnpm run dev
+
+# Test a redirect (should return 301)
+curl -I http://localhost:3000/pricing
+```
+
+Expected output:
+
+```
+HTTP/1.1 301 Moved Permanently
+Location: https://your-marketing-site.com/pricing
+```
+
+### Common Issues
+
+**Redirect loops**: Ensure your external site doesn't redirect back to Makerkit.
+
+**Missing query parameters**: The example code preserves query params. Verify UTM parameters pass through correctly.
+
+**Asset requests**: Don't redirect asset paths like `/images/` or `/_next/`. The middleware should only match page routes.
+
+## Environment-Based Configuration
+
+Use environment variables for different environments:
+
+```typescript {% title="apps/web/proxy.ts" %}
+const EXTERNAL_MARKETING_URL = process.env.EXTERNAL_MARKETING_URL;
+
+export function proxy(req: NextRequest) {
+  // Only redirect if external URL is configured
+  if (!EXTERNAL_MARKETING_URL) {
+    return NextResponse.next();
+  }
+
+  // ... redirect logic
+}
+```
+
+```bash {% title=".env.production" %}
+EXTERNAL_MARKETING_URL=https://your-marketing-site.com
+```
+
+This lets you keep marketing pages in Makerkit during development while redirecting in production.
+
+## Related Resources
+
+- [Marketing Pages](/docs/next-supabase-turbo/development/marketing-pages) for customizing built-in marketing pages
+- [SEO Configuration](/docs/next-supabase-turbo/development/seo) for sitemap and meta tag setup
+- [Legal Pages](/docs/next-supabase-turbo/development/legal-pages) for privacy policy and terms pages