Host Open Notebook at /opennotebook with wildcard subdomain support

Add /opennotebook route embedding Open Notebook via iframe with space-aware
nav breadcrumb. Middleware detects subdomain (e.g. cca.rnotes.online) and sets
rnotes-space cookie. /ai redirects to /opennotebook. Traefik wildcard router
at priority 100 catches *.rnotes.online subdomains.

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

docker-compose.yml

@@ -21,6 +21,11 @@ services:
       - "traefik.http.routers.rnotes.entrypoints=web"
       - "traefik.http.routers.rnotes.priority=130"
       - "traefik.http.services.rnotes.loadbalancer.server.port=3000"
+      # Wildcard subdomain routing (e.g. cca.rnotes.online)
+      - "traefik.http.routers.rnotes-wildcard.rule=HostRegexp(`{sub:[a-z0-9-]+}.rnotes.online`)"
+      - "traefik.http.routers.rnotes-wildcard.entrypoints=web"
+      - "traefik.http.routers.rnotes-wildcard.priority=100"
+      - "traefik.http.routers.rnotes-wildcard.service=rnotes"
     networks:
       - traefik-public
       - rnotes-internal

src/app/ai/page.tsx

@@ -1,48 +1,5 @@
-'use client';
-
-import Link from 'next/link';
-import { OpenNotebookEmbed } from '@/components/OpenNotebookEmbed';
-import { UserMenu } from '@/components/UserMenu';
-import { SearchBar } from '@/components/SearchBar';
+import { redirect } from 'next/navigation';
 
 export default function AIPage() {
-  return (
-    <div className="h-screen flex flex-col bg-[#0a0a0a]">
-      <nav className="border-b border-slate-800 px-4 md:px-6 py-4 flex-shrink-0">
-        <div className="max-w-6xl mx-auto flex items-center justify-between">
-          <div className="flex items-center gap-3">
-            <Link href="/" className="flex-shrink-0">
-              <div className="w-8 h-8 rounded-lg bg-gradient-to-br from-amber-400 to-orange-500 flex items-center justify-center text-sm font-bold text-black">
-                rN
-              </div>
-            </Link>
-            <span className="text-slate-600 hidden sm:inline">/</span>
-            <span className="text-white font-semibold">AI Notebook</span>
-          </div>
-          <div className="flex items-center gap-2 md:gap-4">
-            <div className="hidden md:block w-64">
-              <SearchBar />
-            </div>
-            <Link
-              href="/notebooks"
-              className="text-sm text-slate-400 hover:text-white transition-colors hidden sm:inline"
-            >
-              Notebooks
-            </Link>
-            <Link
-              href="/demo"
-              className="text-sm text-slate-400 hover:text-white transition-colors hidden sm:inline"
-            >
-              Demo
-            </Link>
-            <UserMenu />
-          </div>
-        </div>
-      </nav>
-
-      <main className="flex-1 min-h-0">
-        <OpenNotebookEmbed className="h-full rounded-none border-0" />
-      </main>
-    </div>
-  );
+  redirect('/opennotebook');
 }

src/app/opennotebook/page.tsx

@@ -0,0 +1,57 @@
+'use client';
+
+import Link from 'next/link';
+import { OpenNotebookEmbed } from '@/components/OpenNotebookEmbed';
+import { UserMenu } from '@/components/UserMenu';
+import { SearchBar } from '@/components/SearchBar';
+import { useSpaceContext } from '@/lib/space-context';
+
+export default function OpenNotebookPage() {
+  const space = useSpaceContext();
+
+  return (
+    <div className="h-screen flex flex-col bg-[#0a0a0a]">
+      <nav className="border-b border-slate-800 px-4 md:px-6 py-4 flex-shrink-0">
+        <div className="max-w-6xl mx-auto flex items-center justify-between">
+          <div className="flex items-center gap-3">
+            <Link href="/" className="flex-shrink-0">
+              <div className="w-8 h-8 rounded-lg bg-gradient-to-br from-amber-400 to-orange-500 flex items-center justify-center text-sm font-bold text-black">
+                rN
+              </div>
+            </Link>
+            <span className="text-slate-600 hidden sm:inline">/</span>
+            {space && (
+              <>
+                <span className="text-amber-400 font-medium">{space}</span>
+                <span className="text-slate-600 hidden sm:inline">/</span>
+              </>
+            )}
+            <span className="text-white font-semibold">Open Notebook</span>
+          </div>
+          <div className="flex items-center gap-2 md:gap-4">
+            <div className="hidden md:block w-64">
+              <SearchBar />
+            </div>
+            <Link
+              href="/notebooks"
+              className="text-sm text-slate-400 hover:text-white transition-colors hidden sm:inline"
+            >
+              Notebooks
+            </Link>
+            <Link
+              href="/demo"
+              className="text-sm text-slate-400 hover:text-white transition-colors hidden sm:inline"
+            >
+              Demo
+            </Link>
+            <UserMenu />
+          </div>
+        </div>
+      </nav>
+
+      <main className="flex-1 min-h-0">
+        <OpenNotebookEmbed className="h-full rounded-none border-0" />
+      </main>
+    </div>
+  );
+}

src/lib/space-context.ts

@@ -0,0 +1,36 @@
+'use client';
+
+import { useSyncExternalStore } from 'react';
+
+function getCookie(name: string): string | null {
+  if (typeof document === 'undefined') return null;
+  const match = document.cookie.match(new RegExp(`(?:^|; )${name}=([^;]*)`));
+  return match ? decodeURIComponent(match[1]) : null;
+}
+
+function subscribe(callback: () => void) {
+  // Re-check on visibility change (covers navigation)
+  document.addEventListener('visibilitychange', callback);
+  return () => document.removeEventListener('visibilitychange', callback);
+}
+
+function getSnapshot(): string | null {
+  return getCookie('rnotes-space');
+}
+
+function getServerSnapshot(): string | null {
+  return null;
+}
+
+export function useSpaceContext(): string | null {
+  return useSyncExternalStore(subscribe, getSnapshot, getServerSnapshot);
+}
+
+export function getSpaceFromHeaders(headers: Headers): string | null {
+  const host = headers.get('host') || '';
+  const match = host.match(/^([a-z0-9-]+)\.rnotes\.online$/);
+  if (match && !['www', 'opennotebook', 'api'].includes(match[1])) {
+    return match[1];
+  }
+  return null;
+}

src/middleware.ts

@@ -0,0 +1,27 @@
+import { NextResponse } from 'next/server';
+import type { NextRequest } from 'next/server';
+
+const RESERVED_SUBDOMAINS = new Set(['www', 'opennotebook', 'api']);
+
+export function middleware(request: NextRequest) {
+  const host = request.headers.get('host') || '';
+  const match = host.match(/^([a-z0-9-]+)\.rnotes\.online$/);
+
+  if (match && !RESERVED_SUBDOMAINS.has(match[1])) {
+    const space = match[1];
+    const response = NextResponse.next();
+    response.cookies.set('rnotes-space', space, {
+      path: '/',
+      httpOnly: false,
+      sameSite: 'lax',
+      secure: true,
+    });
+    return response;
+  }
+
+  return NextResponse.next();
+}
+
+export const config = {
+  matcher: ['/((?!_next/static|_next/image|favicon.ico|icon.svg).*)'],
+};