diff --git a/src/lib/auth.ts b/src/lib/auth.ts
new file mode 100644
index 0000000..0673a9f
--- /dev/null
+++ b/src/lib/auth.ts
@@ -0,0 +1,26 @@
+import { cookies } from 'next/headers';
+
+const SESSION_COOKIE = 'admin_session';
+const SESSION_SECRET = 'marines-agen-secret-2024';
+
+export function createSession(): void {
+  const cookieStore = cookies();
+  cookieStore.set(SESSION_COOKIE, SESSION_SECRET, {
+    httpOnly: true,
+    secure: process.env.NODE_ENV === 'production',
+    sameSite: 'lax',
+    maxAge: 60 * 60 * 8, // 8 hours
+    path: '/',
+  });
+}
+
+export function destroySession(): void {
+  const cookieStore = cookies();
+  cookieStore.delete(SESSION_COOKIE);
+}
+
+export function isAuthenticated(): boolean {
+  const cookieStore = cookies();
+  const session = cookieStore.get(SESSION_COOKIE);
+  return session?.value === SESSION_SECRET;
+}