diff --git a/index.html b/index.html
index 23082cc..5ad901c 100644
--- a/index.html
+++ b/index.html
@@ -4,6 +4,29 @@
 <head>
     <meta charset="UTF-8">
     <meta name="robots" content="noindex, nofollow">
+    <!-- Auth Gate -->
+    <script>
+    (function () {
+        var apiKey = localStorage.getItem('posimai_api_key') || '';
+        var token  = localStorage.getItem('posimai_token') || '';
+        if (!apiKey && !token) {
+            location.href = 'https://posimai.soar-enrich.com/login?redirect=' + encodeURIComponent(location.href);
+            return;
+        }
+        if (token && !apiKey) {
+            fetch('https://api.soar-enrich.com/brain/api/auth/session/verify', {
+                headers: { 'Authorization': 'Bearer ' + token }
+            }).then(function (r) { return r.json(); }).then(function (d) {
+                if (!d.ok) {
+                    localStorage.removeItem('posimai_token');
+                    location.href = 'https://posimai.soar-enrich.com/login?redirect=' + encodeURIComponent(location.href);
+                } else if (!d.purchased) {
+                    location.href = 'https://store.posimai.soar-enrich.com/index-c.html';
+                }
+            }).catch(function () { /* オフライン時は通す */ });
+        }
+    })();
+    </script>
     <meta name="viewport" content="width=device-width, initial-scale=1.0, viewport-fit=cover">
     <meta name="description" content="ITエンジニア・デザイナーの学習を加速するイベント情報">
     <title>Posimai Tech Events</title>
