diff --git a/includes/auth.php b/includes/auth.php
new file mode 100644
index 0000000..7462649
--- /dev/null
+++ b/includes/auth.php
@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+require_once __DIR__ . '/config.php';
+
+function isLoggedIn(): bool
+{
+    return isset($_SESSION['user']);
+}
+
+function requireLogin(): void
+{
+    if (!isLoggedIn()) {
+        header('Location: login.php');
+        exit;
+    }
+}
\ No newline at end of file