diff --git a/js/api.js b/js/api.js
index b56fed8..ad6711a 100644
--- a/js/api.js
+++ b/js/api.js
@@ -901,7 +901,17 @@ async function apiFetch(path, options = {}) {
   const token = getToken();
   const headers = { 'Content-Type': 'application/json', ...(options.headers || {}) };
   if (token) headers['Authorization'] = `Bearer ${token}`;
-  const res = await fetch(path, { ...options, headers });
+  // Auto-stringify plain object bodies so callers can pass `{ body: { ... } }`
+  // like LS.post does. Strings / FormData / Blob / URLSearchParams pass through.
+  const opts = { ...options, headers };
+  if (opts.body && typeof opts.body === 'object'
+      && !(opts.body instanceof FormData)
+      && !(opts.body instanceof Blob)
+      && !(opts.body instanceof URLSearchParams)
+      && !(opts.body instanceof ArrayBuffer)) {
+    opts.body = JSON.stringify(opts.body);
+  }
+  const res = await fetch(path, opts);
   if (res.status === 401) {
     removeToken(); removeUser();
     window.location.href = '/login';