diff --git a/cypher-executor/src/routes/portal.ts b/cypher-executor/src/routes/portal.ts
index 5fa1148..d839da5 100644
--- a/cypher-executor/src/routes/portal.ts
+++ b/cypher-executor/src/routes/portal.ts
@@ -746,6 +746,64 @@ portalRouter.post('/portal/admin/libraries', (c) =>
   }),
 );
 
+// POST /portal/daemon/libraries — 小幫手（daemon）連線精靈時把看守資料夾的庫報上來自動登記。
+// t159（2026-07-31 leo prod 實走揪出）：daemon registerLibraries（arcrun-tray main.go:505，t52）
+// 一直在打這個端點，但 cypher 從來沒有它 ⇒ 404 被 daemon「失敗不擋連線」靜默吞掉
+// ⇒ portal_library 登記簿永遠空 ⇒ portal「庫目錄管理」空（資料同步倒是全正常——
+// triplet records 的 library slot 都在，病只在登記簿沒人寫）。
+// 契約照 daemon 既有呼叫：body {email, password, libraries:[{name, display_name}]}。
+// 帳密驗證＝與 /portal/session 同一套（daemon 只在精靈那一刻拿到帳密，不存）。
+// 冪等：已登記（同 name）跳過——重跑精靈不堆重複。
+portalRouter.post('/portal/daemon/libraries', (c) =>
+  run(c, async () => {
+    const body = await c.req.json().catch(() => null);
+    const email = String(body?.email ?? '').trim().toLowerCase();
+    const password = String(body?.password ?? '');
+    if (!email || !password) return c.json({ error: 'email 與 password 必填' }, 400);
+    const items = Array.isArray(body?.libraries) ? body.libraries : [];
+    if (items.length === 0) return c.json({ success: true, registered: [], skipped: [] });
+
+    // 帳密驗證（沿用 /portal/session 的鎖定與驗證機制）
+    if (await isLocked(c.env, email)) return c.json({ error: '登入失敗次數過多，請稍後再試' }, 429);
+    const recordId = await findUserRecordId(c.env, email);
+    const rec = recordId ? await getRecordById(c.env, recordId) : null;
+    if (!rec || (rec.values.status ?? '') !== 'active'
+      || !(await verifyPassword(password, rec.values.password_hash ?? ''))) {
+      await recordLoginFail(c.env, email);
+      return c.json({ error: 'email 或密碼錯誤' }, 401);
+    }
+    await clearLoginFail(c.env, email);
+
+    const seeded = await ensurePortalTemplates(c.env);
+    if (seeded.errors.length > 0) {
+      return c.json({ error: `portal templates seed 失敗：${seeded.errors.join('; ')}` }, 502);
+    }
+    const existing = await listRecordsByTemplate(c.env, LIBRARY_TEMPLATE);
+    const have = new Set(existing.map((l) => l.values.name ?? ''));
+    const ns = portalNamespace(c.env);
+    const registered: string[] = [];
+    const skipped: string[] = [];
+    for (const it of items) {
+      const name = String(it?.name ?? '').trim();
+      const displayName = String(it?.display_name ?? '').trim() || name;
+      if (!isValidLibraryName(name) || name === '*') { skipped.push(name || '(空)'); continue; }
+      if (have.has(name)) { skipped.push(name); continue; }
+      const res = await kbdbFetch(c.env, '/records', {
+        method: 'POST',
+        body: JSON.stringify({
+          template: LIBRARY_TEMPLATE,
+          owner_id: ns,
+          values: { name, display_name: displayName, description: '', status: 'active' },
+        }),
+      });
+      if (!res.ok) throw new KbdbError(`POST /records（portal_library，daemon 登記）→ ${res.status}`);
+      have.add(name);
+      registered.push(name);
+    }
+    return c.json({ success: true, registered, skipped });
+  }),
+);
+
 // PATCH /portal/admin/libraries/:id — 改 display_name/description/status（停用庫＝翻 status slot）。
 portalRouter.patch('/portal/admin/libraries/:id', (c) =>
   run(c, async () => {