Authorization determines what an identified user may access or do. In an AI web application, it can restrict protected routes, limit messages, and prevent one user from reading another user’s data. Authentication establishes identity; being signed in does not by itself grant every permission. section 9.3
Apply checks where each protected action occurs:
- Protect the chat route with Next.js middleware and Clerk’s `auth.protect()`. An index-page redirect can guide users to sign-in, but route protection is the access check. section 9.3.1
- Limit authenticated users to 10 AI messages per day with Upstash Redis in the example configuration; adjust quotas to reflect model costs and expected usage. section 9.3.1
- Grant access to chat histories only to roles or individuals that need it. Keep any impersonation temporary, narrowly scoped, and logged. section 9.5
- Enforce authorization on vector search and storage operations so shared data cannot leak across users; user-based namespaces and metadata filters provide logical isolation. section 11.2.1
Listing 9.3 Configuring Clerk middleware
import { clerkMiddleware, createRouteMatcher } from "@clerk/nextjs/server"; #1
const isProtectedRoute =
createRouteMatcher(["/chat(.*)"]); #2
export default clerkMiddleware(async (auth, req) => {
if (isProtectedRoute(req)) await auth.protect();
const corsResponse = handleCORS(req);
if (corsResponse instanceof NextResponse) {
return corsResponse;
}
const rateLimitResponse = rateLimit(req);
if (rateLimitResponse instanceof NextResponse) {
return rateLimitResponse;
}
return NextResponse.next();
});
export const config = {
matcher: [
// Skip Next.js internals and all static files, unless found in search params
'/((?!_next|[^?]*\\.(?:html?|css|js(?!on)
|jpe?g|webp|png|gif|svg|ttf|woff2?|
ico|csv|docx?|xlsx?|zip|webmanifest)).*)',
// Always run for API routes
'/(api|trpc)(.*)',
]
};
The middleware example uses `createRouteMatcher(["/chat(.*)"])` to identify the protected route and calls `auth.protect()` before continuing through other request checks. section 9.3.1
For a stricter data boundary, dedicated vector databases per user or tenant provide physical separation at greater cost and operational complexity. Authorization remains necessary on vector operations either way. section 11.2.1
