diff --git a/assets/js/pay-vip.js b/assets/js/pay-vip.js
index c78ecd90..78f64be3 100644
--- a/assets/js/pay-vip.js
+++ b/assets/js/pay-vip.js
@@ -11,10 +11,44 @@
     if (window.location.protocol === "https:" && siteUrl.substring(0, 5) === "http:") {
       siteUrl = "https:" + siteUrl.substring(5);
     }
-    if (aksrt.restUrl) {
-      return String(aksrt.restUrl).replace(/\/$/, "");
+    var raw = aksrt.apiUrl || aksrt.restUrl || aksrt.rest_url || "";
+    if (raw) {
+      return String(raw).replace(/\/$/, "");
     }
-    return siteUrl.replace(/\/$/, "") + "/wp-json/aksrt/v1";
+    return siteUrl.replace(/\/$/, "") + "/index.php?rest_route=/aksrt/v1";
+  }
+
+  /**
+   * Join REST root + path [+ query].
+   * Pretty:  /wp-json/aksrt/v1/pay/vip/modal?vip_level=1
+   * Plain:   index.php?rest_route=/aksrt/v1/pay/vip/modal&vip_level=1
+   * Never put a second "?" after rest_route= (that 404s).
+   */
+  function restUrl(path, query) {
+    path = String(path || "");
+    if (path.charAt(0) !== "/") path = "/" + path;
+    var base = restBase();
+    var qstr = "";
+    if (query && typeof query === "object") {
+      var parts = [];
+      Object.keys(query).forEach(function (k) {
+        if (query[k] === undefined || query[k] === null) return;
+        parts.push(encodeURIComponent(k) + "=" + encodeURIComponent(String(query[k])));
+      });
+      qstr = parts.join("&");
+    } else if (typeof query === "string" && query) {
+      qstr = query.replace(/^\?/, "");
+    }
+
+    if (base.indexOf("rest_route=") !== -1) {
+      var url = base + path;
+      if (qstr) url += "&" + qstr;
+      return url;
+    }
+
+    var pretty = base + path;
+    if (qstr) pretty += (pretty.indexOf("?") >= 0 ? "&" : "?") + qstr;
+    return pretty;
   }
 
   function nonceHeaders() {
@@ -24,14 +58,28 @@
   }
 
   function api(path, options) {
+    var opts = Object.assign({}, options || {});
+    var query = opts.query;
+    if (Object.prototype.hasOwnProperty.call(opts, "query")) {
+      delete opts.query;
+    }
+    var onlyPath = String(path || "");
+    var inlineQ = null;
+    var qi = onlyPath.indexOf("?");
+    if (qi >= 0) {
+      inlineQ = onlyPath.slice(qi + 1);
+      onlyPath = onlyPath.slice(0, qi);
+    }
+    var url = restUrl(onlyPath, query || inlineQ);
+
     var merged = Object.assign(
       {
         credentials: "same-origin",
         headers: Object.assign({ "Content-Type": "application/json" }, nonceHeaders()),
       },
-      options || {}
+      opts
     );
-    return fetch(restBase() + path, merged).then(function (r) {
+    return fetch(url, merged).then(function (r) {
       return r
         .json()
         .catch(function () {
@@ -42,7 +90,6 @@
         });
     });
   }
-
   function ensureModalShell() {
     var el = document.getElementById("modal_pay_uservip");
     if (el) return el;
@@ -210,7 +257,7 @@
     if (body) body.innerHTML = '<div class="text-center padding-20 muted-2-color">加载中…</div>';
     openModal();
 
-    api("/pay/vip/modal?vip_level=" + encodeURIComponent(String(level)))
+    api("/pay/vip/modal", { query: { vip_level: level } })
       .then(function (r) {
         loading = false;
         if (r.status === 401) {