diff --git a/webui/src/hooks/__tests__/useMessage.test.ts b/webui/src/hooks/__tests__/useMessage.test.ts
new file mode 100644
index 00000000..85b2ed25
--- /dev/null
+++ b/webui/src/hooks/__tests__/useMessage.test.ts
@@ -0,0 +1,18 @@
+/**
+ * #1145：路由守卫在 app.runWithContext() 中第一次调用 useAuth() → useMessage()。
+ * 此时创建的 discrete app 会从外层应用查找 n-message-provider，message 为 undefined，
+ * 登录成功后 message.success 抛错，跳转不执行。
+ */
+import { describe, expect, it } from 'vitest';
+import { createApp } from 'vue';
+import { useMessage } from '@/hooks/useMessage';
+
+describe('useMessage', () => {
+  it('should return a working message API when first called inside app.runWithContext', () => {
+    const app = createApp({});
+
+    const message = app.runWithContext(() => useMessage());
+
+    expect(typeof message?.success).toBe('function');
+  });
+});
diff --git a/webui/src/hooks/useMessage.ts b/webui/src/hooks/useMessage.ts
index bad2151f..008ca9e0 100644
--- a/webui/src/hooks/useMessage.ts
+++ b/webui/src/hooks/useMessage.ts
@@ -1,6 +1,5 @@
 import { createDiscreteApi } from 'naive-ui';
 import type { GlobalThemeOverrides } from 'naive-ui';
-import { createSharedComposable } from '@vueuse/core';
 
 // Soft Ink toast：反色墨条 —— 所有类型同一深底，语义色只出现在图标上。
 // （组件级 token 可以用 CSS 变量；只有 common 必须是字面量）
@@ -27,9 +26,12 @@ const toastTheme: GlobalThemeOverrides = {
   },
 };
 
-export const useMessage = createSharedComposable(() => {
-  const { message } = createDiscreteApi(['message'], {
-    configProviderProps: { themeOverrides: toastTheme },
-  });
-  return message;
+// 在模块加载时创建：首次调用若发生在路由守卫的 app.runWithContext() 中，
+// discrete app 会从外层应用查找 n-message-provider 而失败（#1145）。
+const { message } = createDiscreteApi(['message'], {
+  configProviderProps: { themeOverrides: toastTheme },
 });
+
+export function useMessage() {
+  return message;
+}