Migrate middleware.ts to proxy.ts for Next.js 16 and fix build errors

Next.js 16 renamed middleware to proxy. Merged session-based auth and
API key auth into a single proxy.ts. Also fixed: auth route handler
exports, missing card component, Button asChild type errors, signIn
return type, Drizzle eq() type narrowing, and useSearchParams suspense
boundary.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

next-env.d.ts

@@ -1,6 +1,6 @@
 /// <reference types="next" />
 /// <reference types="next/image-types/global" />
-import "./.next/dev/types/routes.d.ts";
+import "./.next/types/routes.d.ts";
 
 // NOTE: This file should not be edited
 // see https://nextjs.org/docs/app/api-reference/config/typescript for more information.

src/app/(public)/login/page.tsx

@@ -1,6 +1,6 @@
 "use client";
 
-import { useState, useEffect } from "react";
+import { useState, useEffect, Suspense } from "react";
 import Link from "next/link";
 import { useSearchParams } from "next/navigation";
 import { signIn } from "next-auth/react";
@@ -13,6 +13,14 @@ import { AlertCircle } from "lucide-react";
 import { toast } from "sonner";
 
 export default function LoginPage() {
+  return (
+    <Suspense>
+      <LoginPageContent />
+    </Suspense>
+  );
+}
+
+function LoginPageContent() {
   const [email, setEmail] = useState("");
   const [password, setPassword] = useState("");
   const [isLoading, setIsLoading] = useState(false);
@@ -36,15 +44,11 @@ export default function LoginPage() {
     setError(null);
     setIsLoading(true);
     try {
-      const result = await signIn("credentials", {
+      await signIn("credentials", {
         email,
         password,
         redirectTo: "/app",
       });
-      // If signIn returns with ok: false, it means auth failed
-      if (result && !result.ok) {
-        setError("Invalid email or password");
-      }
     } catch {
       setError("An error occurred. Please try again.");
     } finally {

src/app/(public)/navbar.tsx

@@ -2,8 +2,9 @@
 
 import Link from "next/link";
 import { useSession } from "next-auth/react";
-import { Button } from "@/components/ui/button";
+import { buttonVariants } from "@/components/ui/button";
 import { ChartColumn } from "lucide-react";
+import { cn } from "@/lib/utils";
 
 export function Navbar() {
   const { data: session } = useSession();
@@ -19,17 +20,26 @@ export function Navbar() {
         </div>
         <div className="flex items-center gap-3">
           {session ? (
-            <Button size="sm" className="font-mono text-xs" asChild>
-              <Link href="/app">Go to App</Link>
-            </Button>
+            <Link
+              href="/app"
+              className={cn(buttonVariants({ size: "sm" }), "font-mono text-xs")}
+            >
+              Go to App
+            </Link>
           ) : (
             <>
-              <Button variant="ghost" size="sm" className="font-mono text-xs" asChild>
-                <Link href="/login">Log in</Link>
-              </Button>
-              <Button size="sm" className="font-mono text-xs" asChild>
-                <Link href="/register">Get Started</Link>
-              </Button>
+              <Link
+                href="/login"
+                className={cn(buttonVariants({ variant: "ghost", size: "sm" }), "font-mono text-xs")}
+              >
+                Log in
+              </Link>
+              <Link
+                href="/register"
+                className={cn(buttonVariants({ size: "sm" }), "font-mono text-xs")}
+              >
+                Get Started
+              </Link>
             </>
           )}
         </div>

src/app/(public)/page.tsx

@@ -1,5 +1,6 @@
 import Link from "next/link";
-import { Button } from "@/components/ui/button";
+import { buttonVariants } from "@/components/ui/button";
+import { cn } from "@/lib/utils";
 import { Navbar } from "./navbar";
 import {
   ChartColumn,
@@ -36,19 +37,18 @@ export default function LandingPage() {
             keyboard-driven workspace.
           </p>
           <div className="flex items-center justify-center gap-3">
-            <Button size="lg" className="font-mono text-sm gap-2" asChild>
-              <Link href="/register">
+            <Link
+              href="/register"
+              className={cn(buttonVariants({ size: "lg" }), "font-mono text-sm gap-2")}
+            >
               Start Annotating <ArrowRight className="w-4 h-4" />
             </Link>
-            </Button>
-            <Button
-              size="lg"
-              variant="outline"
-              className="font-mono text-sm"
-              asChild
+            <Link
+              href="/app"
+              className={cn(buttonVariants({ size: "lg", variant: "outline" }), "font-mono text-sm")}
             >
-              <Link href="/app">Try Demo</Link>
-            </Button>
+              Try Demo
+            </Link>
           </div>
         </div>
       </section>
@@ -162,11 +162,12 @@ export default function LandingPage() {
         <p className="text-muted-foreground text-sm mb-6">
           No credit card required. Start annotating charts in seconds.
         </p>
-        <Button size="lg" className="font-mono text-sm gap-2" asChild>
-          <Link href="/register">
+        <Link
+          href="/register"
+          className={cn(buttonVariants({ size: "lg" }), "font-mono text-sm gap-2")}
+        >
           Create Free Account <ArrowRight className="w-4 h-4" />
         </Link>
-        </Button>
       </section>
 
       {/* Footer */}

src/app/api/auth/[...nextauth]/route.ts

@@ -1 +1,2 @@
-export { GET, POST } from "@/auth";
+import { handlers } from "@/auth";
+export const { GET, POST } = handlers;

src/components/ui/card.tsx

@@ -0,0 +1,79 @@
+import * as React from "react"
+
+import { cn } from "@/lib/utils"
+
+const Card = React.forwardRef<
+  HTMLDivElement,
+  React.HTMLAttributes<HTMLDivElement>
+>(({ className, ...props }, ref) => (
+  <div
+    ref={ref}
+    className={cn(
+      "rounded-lg border bg-card text-card-foreground shadow-sm",
+      className
+    )}
+    {...props}
+  />
+))
+Card.displayName = "Card"
+
+const CardHeader = React.forwardRef<
+  HTMLDivElement,
+  React.HTMLAttributes<HTMLDivElement>
+>(({ className, ...props }, ref) => (
+  <div
+    ref={ref}
+    className={cn("flex flex-col space-y-1.5 p-6", className)}
+    {...props}
+  />
+))
+CardHeader.displayName = "CardHeader"
+
+const CardTitle = React.forwardRef<
+  HTMLDivElement,
+  React.HTMLAttributes<HTMLDivElement>
+>(({ className, ...props }, ref) => (
+  <div
+    ref={ref}
+    className={cn(
+      "text-2xl font-semibold leading-none tracking-tight",
+      className
+    )}
+    {...props}
+  />
+))
+CardTitle.displayName = "CardTitle"
+
+const CardDescription = React.forwardRef<
+  HTMLDivElement,
+  React.HTMLAttributes<HTMLDivElement>
+>(({ className, ...props }, ref) => (
+  <div
+    ref={ref}
+    className={cn("text-sm text-muted-foreground", className)}
+    {...props}
+  />
+))
+CardDescription.displayName = "CardDescription"
+
+const CardContent = React.forwardRef<
+  HTMLDivElement,
+  React.HTMLAttributes<HTMLDivElement>
+>(({ className, ...props }, ref) => (
+  <div ref={ref} className={cn("p-6 pt-0", className)} {...props} />
+))
+CardContent.displayName = "CardContent"
+
+const CardFooter = React.forwardRef<
+  HTMLDivElement,
+  React.HTMLAttributes<HTMLDivElement>
+>(({ className, ...props }, ref) => (
+  <div
+    ref={ref}
+    className={cn("flex items-center p-6 pt-0", className)}
+    {...props}
+  />
+))
+CardFooter.displayName = "CardFooter"
+
+export { Card, CardHeader, CardFooter, CardTitle, CardDescription, CardContent }

src/lib/auth.ts

@@ -1,6 +1,10 @@
 import { auth } from "@/auth";
 
-export async function getAuthUser() {
+export type AuthUser = { id: string; name?: string | null; email?: string | null; image?: string | null };
+
+export async function getAuthUser(): Promise<AuthUser | null> {
   const session = await auth();
-  return session?.user ?? null;
+  const user = session?.user;
+  if (!user?.id) return null;
+  return user as AuthUser;
 }

src/middleware.ts

@@ -1,44 +0,0 @@
-import { auth } from "@/auth";
-import { NextResponse } from "next/server";
-
-export const middleware = auth((req) => {
-  const { pathname } = req.nextUrl;
-  const isAuthenticated = !!req.auth;
-
-  // Protect /api/* except /api/auth/* and /api/health
-  if (pathname.startsWith("/api/")) {
-    const isAuthRoute = pathname.startsWith("/api/auth/");
-    const isHealthRoute = pathname === "/api/health";
-
-    if (!isAuthRoute && !isHealthRoute && !isAuthenticated) {
-      return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
-    }
-
-    return NextResponse.next();
-  }
-
-  // Redirect authenticated users away from /login and /register
-  if (isAuthenticated && (pathname === "/login" || pathname === "/register")) {
-    return NextResponse.redirect(new URL("/app", req.nextUrl.origin));
-  }
-
-  // Protect /app/* routes — redirect unauthenticated users to /login
-  if (pathname.startsWith("/app") && !isAuthenticated) {
-    return NextResponse.redirect(new URL("/login", req.nextUrl.origin));
-  }
-
-  return NextResponse.next();
-});
-
-export const config = {
-  matcher: [
-    /*
-     * Match all request paths except:
-     * - _next/static  (static files)
-     * - _next/image   (image optimisation)
-     * - favicon.ico / favicon.png / favicon.svg
-     * - public assets (top-level files that are not pages)
-     */
-    "/((?!_next/static|_next/image|favicon\\.ico|favicon\\.png|favicon\\.svg).*)",
-  ],
-};

src/proxy.ts

@@ -1,42 +1,53 @@
+import { auth } from "@/auth";
 import { NextResponse } from "next/server";
-import type { NextRequest } from "next/server";
 
-export function proxy(request: NextRequest) {
-  const { pathname } = request.nextUrl;
+export const proxy = auth((req) => {
+  const { pathname } = req.nextUrl;
+  const isAuthenticated = !!req.auth;
 
-  // Skip auth check for the health endpoint
-  if (pathname === "/api/health") {
-    return NextResponse.next();
-  }
+  // Protect /api/* except /api/auth/* and /api/health
+  if (pathname.startsWith("/api/")) {
+    const isAuthRoute = pathname.startsWith("/api/auth/");
+    const isHealthRoute = pathname === "/api/health";
 
+    if (!isAuthRoute && !isHealthRoute && !isAuthenticated) {
+      // Allow external clients with a valid API key
       const apiKey = process.env.API_KEY;
-
-  // If API_KEY is not configured, skip auth check (fail-open for development)
-  if (!apiKey) {
-    console.warn(
-      "Warning: API_KEY environment variable is not set. API authentication is disabled."
-    );
+      if (apiKey) {
+        const requestApiKey = req.headers.get("X-API-Key");
+        if (requestApiKey === apiKey) {
           return NextResponse.next();
         }
-
-  const requestApiKey = request.headers.get("X-API-Key");
-
-  // Allow same-origin browser requests (UI -> /api/*) without exposing API_KEY to client JS.
-  // Keep API key auth for non-browser/external clients.
-  const fetchSite = request.headers.get("sec-fetch-site");
-  const isSameOriginBrowserRequest = fetchSite === "same-origin";
-
-  if (isSameOriginBrowserRequest) {
-    return NextResponse.next();
       }
 
-  if (!requestApiKey || requestApiKey !== apiKey) {
       return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
     }
 
     return NextResponse.next();
-}
+  }
+
+  // Redirect authenticated users away from /login and /register
+  if (isAuthenticated && (pathname === "/login" || pathname === "/register")) {
+    return NextResponse.redirect(new URL("/app", req.nextUrl.origin));
+  }
+
+  // Protect /app/* routes — redirect unauthenticated users to /login
+  if (pathname.startsWith("/app") && !isAuthenticated) {
+    return NextResponse.redirect(new URL("/login", req.nextUrl.origin));
+  }
+
+  return NextResponse.next();
+});
 
 export const config = {
-  matcher: ["/api/:path*"],
+  matcher: [
+    /*
+     * Match all request paths except:
+     * - _next/static  (static files)
+     * - _next/image   (image optimisation)
+     * - favicon.ico / favicon.png / favicon.svg
+     * - public assets (top-level files that are not pages)
+     */
+    "/((?!_next/static|_next/image|favicon\\.ico|favicon\\.png|favicon\\.svg).*)",
+  ],
 };