diff --git a/app/[locale]/login/page.tsx b/app/[locale]/login/page.tsx
index 920eee4..67a9a04 100644
--- a/app/[locale]/login/page.tsx
+++ b/app/[locale]/login/page.tsx
@@ -1,8 +1,10 @@
 import type { Metadata } from "next";
+import { Suspense } from "react";
 import { setRequestLocale, getTranslations } from "next-intl/server";
 import { hasLocale } from "next-intl";
 import { notFound } from "next/navigation";
 import { SignInButton } from "@/app/components/SignInButton";
+import { LoginErrorNotice } from "@/app/components/LoginErrorNotice";
 import { routing } from "@/i18n/routing";
 
 // SEO: 登录页不参与 index（搜索引擎不需要收录登录入口）
@@ -30,11 +32,20 @@ export default async function LoginPage({ params }: Props) {
           <h1 className="text-3xl font-bold">{t("heading")}</h1>
           <p className="text-muted-foreground">{t("subheading")}</p>
         </div>
+        <Suspense fallback={null}>
+          <LoginErrorNotice
+            messages={{
+              discord_canary: t("errorDiscordCanary"),
+              generic: t("errorGeneric"),
+            }}
+          />
+        </Suspense>
         <div className="flex flex-col items-center gap-3">
           <SignInButton provider="github" label={t("github")} />
-          {/* Discord 登录暂时下线：后端 provider 已就绪，但新用户"验证邮箱→建号"
-              流程（OTP wiring）还没做完，先不对外暴露以免分叉账号。做完后取消注释即可。 */}
-          {/* <SignInButton provider="discord" label={t("discord")} /> */}
+          {/* Discord 登录灰度中：后端按 Discord id 白名单放行（auth.discord.allowlist），
+              名单外的人点了会被回调弹回 /login?error=discord_canary。GA（OTP wiring 完成、
+              清空白名单）后此按钮即对所有人开放。 */}
+          <SignInButton provider="discord" label={t("discord")} />
         </div>
       </div>
     </div>
diff --git a/app/components/LoginErrorNotice.tsx b/app/components/LoginErrorNotice.tsx
new file mode 100644
index 0000000..bc3d3d0
--- /dev/null
+++ b/app/components/LoginErrorNotice.tsx
@@ -0,0 +1,25 @@
+"use client";
+
+import { useSearchParams } from "next/navigation";
+
+// 登录页顶端的错误提示。后端 OAuth 回调失败会 302 到 /login?error=xxx。
+// 用 useSearchParams（客户端读 query）而非 server 读 searchParams，避免整页退回
+// 动态渲染（登录页要保持 SSG，见 CLAUDE.md 路由分类约束）。父级用 <Suspense> 包裹。
+// 文案由 server 端 getTranslations 取好后作为 prop 传入，省一套 client i18n provider。
+export function LoginErrorNotice({
+  messages,
+}: {
+  messages: Record<string, string>;
+}) {
+  const error = useSearchParams().get("error");
+  if (!error) return null;
+  const msg = messages[error] ?? messages.generic;
+  return (
+    <div
+      role="alert"
+      className="w-full rounded-md border border-amber-300 bg-amber-50 px-4 py-3 text-sm text-amber-900 dark:border-amber-800 dark:bg-amber-950 dark:text-amber-200"
+    >
+      {msg}
+    </div>
+  );
+}
diff --git a/generated/doc-contributors.json b/generated/doc-contributors.json
index 822d731..af4a834 100644
--- a/generated/doc-contributors.json
+++ b/generated/doc-contributors.json
@@ -1,6 +1,6 @@
 {
   "repo": "InvolutionHell/involutionhell",
-  "generatedAt": "2026-05-24T18:19:10.363Z",
+  "generatedAt": "2026-07-24T13:55:10.610Z",
   "docsDir": "content/docs",
   "totalDocs": 144,
   "results": [
@@ -2196,9 +2196,9 @@
           "githubId": "123258594",
           "contributions": 2,
           "lastContributedAt": "2025-09-29T10:32:11.000Z",
-          "login": "PenghaoJiang",
+          "login": "OvOhao",
           "avatarUrl": "https://avatars.githubusercontent.com/u/123258594?v=4",
-          "htmlUrl": "https://github.com/PenghaoJiang"
+          "htmlUrl": "https://github.com/OvOhao"
         },
         {
           "githubId": "41898282",
@@ -2816,9 +2816,9 @@
           "githubId": "76551253",
           "contributions": 1,
           "lastContributedAt": "2025-10-06T00:30:18.000Z",
-          "login": "840691168",
+          "login": "YangLiu-Lewis",
           "avatarUrl": "https://avatars.githubusercontent.com/u/76551253?v=4",
-          "htmlUrl": "https://github.com/840691168"
+          "htmlUrl": "https://github.com/YangLiu-Lewis"
         }
       ]
     },
diff --git a/messages/en.json b/messages/en.json
index 2d7148b..484d1d1 100644
--- a/messages/en.json
+++ b/messages/en.json
@@ -70,7 +70,9 @@
     "heading": "Sign In",
     "subheading": "Sign in to access protected pages",
     "github": "Sign in with GitHub",
-    "discord": "Sign in with Discord"
+    "discord": "Sign in with Discord",
+    "errorDiscordCanary": "Discord sign-in is in limited testing and not open yet — stay tuned!",
+    "errorGeneric": "Sign-in didn't complete. Please try again."
   },
   "settings": {
     "theme": {
diff --git a/messages/zh.json b/messages/zh.json
index 7b935f7..7355d94 100644
--- a/messages/zh.json
+++ b/messages/zh.json
@@ -70,7 +70,9 @@
     "heading": "登录",
     "subheading": "请登录以访问受保护的页面",
     "github": "用 GitHub 登录",
-    "discord": "用 Discord 登录"
+    "discord": "用 Discord 登录",
+    "errorDiscordCanary": "Discord 登录正在灰度测试中，暂未对外开放，敬请期待～",
+    "errorGeneric": "登录未完成，请重试。"
   },
   "settings": {
     "theme": {