diff --git a/public/js/umami-share.js b/public/js/umami-share.js
new file mode 100644
index 0000000..4e090c9
--- /dev/null
+++ b/public/js/umami-share.js
@@ -0,0 +1,47 @@
+(function (global) {
+  const cacheKey = 'umami-share-cache';
+  const cacheTTL = 3600_000; // 1h
+
+  async function fetchShareData(baseUrl, shareId) {
+    const cached = localStorage.getItem(cacheKey);
+    if (cached) {
+      try {
+        const parsed = JSON.parse(cached);
+        if (Date.now() - parsed.timestamp < cacheTTL) {
+          return parsed.value;
+        }
+      } catch {
+        localStorage.removeItem(cacheKey);
+      }
+    }
+    const res = await fetch(`${baseUrl}/api/share/${shareId}`);
+    if (!res.ok) {
+      throw new Error('获取 Umami 分享信息失败');
+    }
+    const data = await res.json();
+    localStorage.setItem(cacheKey, JSON.stringify({ timestamp: Date.now(), value: data }));
+    return data;
+  }
+
+  /**
+   * 获取 Umami 分享数据（websiteId、token）。
+   * 在缓存 TTL 内复用；并用全局 Promise 避免并发请求。
+   * @param {string} baseUrl
+   * @param {string} shareId
+   * @returns {Promise<{websiteId: string, token: string}>}
+   */
+  global.getUmamiShareData = function (baseUrl, shareId) {
+    if (!global.__umamiSharePromise) {
+      global.__umamiSharePromise = fetchShareData(baseUrl, shareId).catch((err) => {
+        delete global.__umamiSharePromise;
+        throw err;
+      });
+    }
+    return global.__umamiSharePromise;
+  };
+
+  global.clearUmamiShareCache = function () {
+    localStorage.removeItem(cacheKey);
+    delete global.__umamiSharePromise;
+  };
+})(window);
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