's'

app/api/vip/check-by-email/route.ts

@@ -35,6 +35,8 @@ type RecoveryResult = {
   source?: string;
 };
 
+const inflightEmailChecks = new Map<string, Promise<PayjsVipEmailResult | null>>();
+
 const PAYJS_CHECK_BY_EMAIL_TIMEOUT =
   Number(process.env.PAYJSAPI_CHECK_BY_EMAIL_TIMEOUT) || 20000;
 const PAYJS_CHECK_BY_EMAIL_RETRIES =
@@ -62,6 +64,13 @@ async function checkVipByEmailFromPayjsapi(
   password: string,
   userId?: string
 ): Promise<PayjsVipEmailResult | null> {
+  const inflightKey = `${email}::${userId || ""}`;
+  const existed = inflightEmailChecks.get(inflightKey);
+  if (existed) {
+    return existed;
+  }
+
+  const task = (async () => {
   const payConfig = getPaymentConfig();
   const primaryUrl = resolvePayApiUrl(request);
   const localUrl = getLocalPayApiUrl();
@@ -125,6 +134,14 @@ async function checkVipByEmailFromPayjsapi(
     }
   }
   return null;
+  })();
+
+  inflightEmailChecks.set(inflightKey, task);
+  try {
+    return await task;
+  } finally {
+    inflightEmailChecks.delete(inflightKey);
+  }
 }
 
 async function loginPocketBaseUser(