diff --git a/app/composables/useAuth.ts b/app/composables/useAuth.ts
index a11bca6..7d95bcd 100644
--- a/app/composables/useAuth.ts
+++ b/app/composables/useAuth.ts
@@ -1,5 +1,15 @@
 import type { ZitadelAuth } from "@kuns/zitadel-auth";
 
+/** API call failure carrying the HTTP status (401 = authenticated but not authorized). */
+export class ApiError extends Error {
+  constructor(
+    message: string,
+    public status: number,
+  ) {
+    super(message);
+  }
+}
+
 // Access the bootstrap-provided Zitadel auth instance + a small JSON helper for /api calls.
 // By the time any component mounts, the plugin has gated auth, so `auth` is authenticated.
 // `auth.fetch` auto-attaches the Bearer access token.
@@ -16,7 +26,7 @@ export function useAuth() {
       } catch {
         // non-JSON error body
       }
-      throw new Error(message);
+      throw new ApiError(message, res.status);
     }
     if (res.status === 204) return undefined as T;
     return (await res.json()) as T;
diff --git a/app/pages/index.vue b/app/pages/index.vue
index 88138c6..819fc54 100644
--- a/app/pages/index.vue
+++ b/app/pages/index.vue
@@ -1,7 +1,10 @@
 <script setup lang="ts">
+import { ApiError } from "~/composables/useAuth";
+
 interface List {
   id: string;
   name: string;
+  ownerId?: string | null;
 }
 interface Task {
   id: string;
@@ -10,6 +13,7 @@ interface Task {
   description: string | null;
   source: string;
   consumed: boolean;
+  ownerId?: string | null;
   createdAt: string;
 }
 
@@ -22,6 +26,21 @@ const loadingLists = ref(true);
 const loadingTasks = ref(false);
 const error = ref<string | null>(null);
 
+// Authenticated but the token lacks the required Zitadel project role → API answers 401.
+const missingRole = ref(false);
+
+// Defense-in-depth: the server already scopes every query by the token's sub; additionally
+// hide anything not owned by the current user. Absent ownerId = legacy (pre-multi-user) row.
+const mine = (x: { ownerId?: string | null }) => !x.ownerId || x.ownerId === auth.user?.sub;
+
+function handleApiError(e: unknown) {
+  if (e instanceof ApiError && e.status === 401) {
+    missingRole.value = true;
+  } else {
+    error.value = (e as Error).message;
+  }
+}
+
 const title = ref("");
 const description = ref("");
 const showNote = ref(false);
@@ -43,12 +62,12 @@ async function refreshLists() {
   loadingLists.value = true;
   error.value = null;
   try {
-    lists.value = await api<List[]>("/lists");
+    lists.value = (await api<List[]>("/lists")).filter(mine);
     if (lists.value.length && !lists.value.some((l) => l.id === selectedId.value)) {
       await selectList(lists.value[0]!.id);
     }
   } catch (e) {
-    error.value = (e as Error).message;
+    handleApiError(e);
   } finally {
     loadingLists.value = false;
   }
@@ -66,9 +85,9 @@ async function refreshTasks() {
   loadingTasks.value = true;
   error.value = null;
   try {
-    tasks.value = await api<Task[]>(`/lists/${selectedId.value}/tasks`);
+    tasks.value = (await api<Task[]>(`/lists/${selectedId.value}/tasks`)).filter(mine);
   } catch (e) {
-    error.value = (e as Error).message;
+    handleApiError(e);
   } finally {
     loadingTasks.value = false;
   }
@@ -95,7 +114,7 @@ async function addTask() {
     showNote.value = false;
     titleInput.value?.focus();
   } catch (e) {
-    error.value = (e as Error).message;
+    handleApiError(e);
   } finally {
     adding.value = false;
   }
@@ -135,7 +154,19 @@ onMounted(() => {
     <main class="content">
       <p v-if="error" class="error" role="alert">{{ error }}</p>
 
-      <template v-if="loadingLists">
+      <template v-if="missingRole">
+        <div class="empty">
+          <p class="empty-mark">⚠</p>
+          <p class="empty-title">No access yet</p>
+          <p class="muted">
+            You're signed in, but your account is missing the “user” role for ClaudeDo.
+            Ask the admin to grant it in Zitadel, then sign in again.
+          </p>
+          <button class="link" @click="auth.logout()">Sign out</button>
+        </div>
+      </template>
+
+      <template v-else-if="loadingLists">
         <p class="muted">Loading lists…</p>
       </template>
 
@@ -172,7 +203,7 @@ onMounted(() => {
       </template>
     </main>
 
-    <footer v-if="lists.length" class="dock">
+    <footer v-if="lists.length && !missingRole" class="dock">
       <button
         v-if="lists.length > 1"
         class="list-pill"