diff --git a/lib/openai/OpenAIResult.ts b/lib/openai/OpenAIResult.ts
index 3f9db214..f7dfaa69 100644
--- a/lib/openai/OpenAIResult.ts
+++ b/lib/openai/OpenAIResult.ts
@@ -1,6 +1,6 @@
 import { createParser, ParsedEvent, ReconnectInterval } from "eventsource-parser";
-import { checkOpenaiApiKeys } from "~/lib/openai/openai";
-import { sample } from "../../utils/fp";
+import { formatResult } from "~/lib/openai/formatResult";
+import { selectApiKey } from "~/lib/openai/selectApiKey";
 
 // TODO: maybe chat with video?
 export type ChatGPTAgent = "user" | "system" | "assistant";
@@ -22,38 +22,17 @@ export interface OpenAIStreamPayload {
   n: number;
 }
 
-function formatResult(result: any) {
-  const answer = result.choices[0].message?.content || "";
-  if (answer.startsWith("\n\n")) {
-    return answer.substring(2);
-  }
-  return answer;
-}
-
-function selectApiKey(apiKey: string | undefined) {
-  if (apiKey && checkOpenaiApiKeys(apiKey)) {
-    const userApiKeys = apiKey.split(",");
-    return sample(userApiKeys);
-  }
-
-  // don't need to validate anymore, already verified in middleware?
-  const myApiKeyList = process.env.OPENAI_API_KEY;
-  const luckyApiKey = sample(myApiKeyList?.split(","));
-  return luckyApiKey || "";
-}
-
 export async function OpenAIResult(
   payload: OpenAIStreamPayload,
-  apiKey?: string
+  apiKey: string
 ) {
   const encoder = new TextEncoder();
   const decoder = new TextDecoder();
-  const openai_api_key = selectApiKey(apiKey);
 
   const res = await fetch("https://api.openai.com/v1/chat/completions", {
     headers: {
       "Content-Type": "application/json",
-      Authorization: `Bearer ${openai_api_key ?? ""}`,
+      Authorization: `Bearer ${apiKey ?? ""}`,
     },
     method: "POST",
     body: JSON.stringify(payload),
diff --git a/lib/openai/formatResult.ts b/lib/openai/formatResult.ts
new file mode 100644
index 00000000..904d9fc0
--- /dev/null
+++ b/lib/openai/formatResult.ts
@@ -0,0 +1,7 @@
+export function formatResult(result: any) {
+  const answer = result.choices[0].message?.content || "";
+  if (answer.startsWith("\n\n")) {
+    return answer.substring(2);
+  }
+  return answer;
+}
diff --git a/lib/openai/selectApiKey.ts b/lib/openai/selectApiKey.ts
new file mode 100644
index 00000000..379e9cdb
--- /dev/null
+++ b/lib/openai/selectApiKey.ts
@@ -0,0 +1,23 @@
+import { activateLicenseKey } from "~/lib/lemon";
+import { checkOpenaiApiKeys } from "~/lib/openai/openai";
+import { sample } from "~/utils/fp";
+
+export async function selectApiKey(apiKey: string | undefined) {
+  if (apiKey) {
+    if (checkOpenaiApiKeys(apiKey)) {
+      const userApiKeys = apiKey.split(",");
+      return sample(userApiKeys);
+    }
+
+    // user is using validated licenseKey
+    const activated = await activateLicenseKey(apiKey);
+    if (!activated) {
+      throw new Error("licenseKey is not validated!");
+    }
+  }
+
+  // don't need to validate anymore, already verified in middleware?
+  const myApiKeyList = process.env.OPENAI_API_KEY;
+  const luckyApiKey = sample(myApiKeyList?.split(","));
+  return luckyApiKey || "";
+}
diff --git a/pages/api/summarize.ts b/pages/api/summarize.ts
index caa0de7f..3bf06e3d 100644
--- a/pages/api/summarize.ts
+++ b/pages/api/summarize.ts
@@ -1,10 +1,15 @@
 import { Redis } from "@upstash/redis";
 import type { NextFetchEvent, NextRequest } from "next/server";
 import { NextResponse } from "next/server";
+import { activateLicenseKey } from "~/lib/lemon";
+import { selectApiKey } from "~/lib/openai/selectApiKey";
 import { fetchSubtitle } from "../../lib/bilibili";
 import { isDev } from "../../utils/env";
 import { OpenAIResult } from "../../lib/openai/OpenAIResult";
-import { getChunckedTranscripts, getSummaryPrompt } from "../../lib/openai/prompt";
+import {
+  getChunckedTranscripts,
+  getSummaryPrompt,
+} from "../../lib/openai/prompt";
 
 export const config = {
   runtime: "edge",
@@ -57,7 +62,8 @@ export default async function handler(
       n: 1,
     };
 
-    const result = await OpenAIResult(payload, apiKey);
+    const openaiApiKey = await selectApiKey(apiKey);
+    const result = await OpenAIResult(payload, openaiApiKey);
     // TODO: add better logging when dev or prod
     console.log("result", result);
     const redis = Redis.fromEnv();