Event-Driven by
Default.

import { NextResponse } from 'next/server';
import type { NextRequest } from 'next/server';

export async function middleware(req: NextRequest) {
  const url = req.nextUrl;
  
  // Get hostname (e.g., 'swadeshibookstore.com')
  const hostname = req.headers.get('host');
  
  // Exclude API, assets, and system routes
  if (url.pathname.startsWith('/_next') || 
      url.pathname.startsWith('/api')) {
    return NextResponse.next();
  }

  // Rewrite to dynamic tenant route
  // -> app/[tenant]/page.tsx
  return NextResponse.rewrite(
    new URL(`/${hostname}${url.pathname}`, req.url)
  );
}