diff --git a/app.py b/app.py
index 65cd993..109bea0 100644
--- a/app.py
+++ b/app.py
@@ -2,7 +2,7 @@
 import os
 import vertexai
 import logging
-from fastapi import FastAPI
+from fastapi import FastAPI, HTTPException
 from fastapi.responses import StreamingResponse
 from fastapi.staticfiles import StaticFiles
 from pydantic import BaseModel
@@ -18,16 +18,15 @@ SESSION_CACHE = LRUCache(15)
 logging.basicConfig(format='%(levelname)s:%(message)s', level=logging.DEBUG)
 
 
-def generate():
-  vertexai.init(project=PROJECT_ID, location="us-central1")
-  model = GenerativeModel(
-    "gemini-1.5-flash-001",
-    # system_instruction=[textsi_1]
-  )
+def generate(model: str, instruction: str):
+    vertexai.init(project=PROJECT_ID, location="us-central1")
+    session = GenerativeModel(
+      model,
+      system_instruction=[instruction]
+    )
 
-  return model.start_chat()
+    return session.start_chat()
 
-# textsi_1 = """你要用中文回答一个德语刚入门的新手的回答，先用德语回答然后在用中文解释这个回答并给出建议"""
 
 generation_config = {
     "max_output_tokens": 1024,
@@ -73,6 +72,24 @@ app = FastAPI(
 )
 
 
+class SessionRequest(BaseModel):
+    instruction: str = "你现在是一只喜爱 Lisp 并且喜欢用 Eamcs 编辑的狐狸，\
+回答问题时尽量使用符合 Lisp 哲学例如递归等概念进行回答。"
+    session_uuid: str
+    model: str = 'gemini-1.5-flash-001'
+
+
+@app.post("/generate_session")
+async def generate_session(request: SessionRequest):
+    if SESSION_CACHE.get(request.session_uuid):
+      raise HTTPException(500)
+
+    model = generate(request.model, request.instruction)
+
+    SESSION_CACHE[request.session_uuid] = model
+    logging.info(f"Buid new session: {request.session_uuid}")
+
+
 class ChatRequest(BaseModel):
     prompt: str
     session_uuid: str
@@ -80,13 +97,10 @@ class ChatRequest(BaseModel):
 
 @app.post("/generate_text_stream")
 async def generate_text(request: ChatRequest):
-    if model := SESSION_CACHE.get(request.session_uuid):
-        return StreamingResponse(stream_chat(model, request.prompt),media_type="text/plain")
+    if session := SESSION_CACHE.get(request.session_uuid):
+        return StreamingResponse(stream_chat(session, request.prompt), media_type="text/plain")
 
-    model = generate()
+    raise HTTPException(404)
 
-    SESSION_CACHE[request.session_uuid] = model
-    logging.info(f"Buid new session: {request.session_uuid}")
-    return StreamingResponse(stream_chat(model, request.prompt),media_type="text/plain")
 
 app.mount("/", StaticFiles(directory="static", html=True), name="static")
diff --git a/static/script.js b/static/script.js
index 79562a8..73447cc 100644
--- a/static/script.js
+++ b/static/script.js
@@ -43,6 +43,43 @@ async function sendMessage() {
   hideTypingIndicator();
 }
 
+async function generateSession() {
+  try {
+    const response = await fetch("./generate_session", {
+      method: "POST",
+      headers: {
+        "Content-Type": "application/json",
+      },
+      body: JSON.stringify({ session_uuid }),
+    });
+
+    if (!response.ok) {
+      console.error("Error:", response.statusText);
+      return "Error occurred while generating response.";
+    }
+
+    const reader = response.body.getReader();
+    const decoder = new TextDecoder();
+    let isFinished = false;
+    let generatedTextContent = "";
+
+    while (!isFinished) {
+      const { done, value } = await reader.read();
+      if (done) {
+        isFinished = true;
+        break;
+      }
+      generatedTextContent += decoder.decode(value, {stream: true});
+    }
+
+    return generatedTextContent;
+  } catch (error) {
+    console.error("Error:", error);
+    return "An error occurred.";
+  }
+}
+
+
 async function generateText(prompt) {
   try {
     const response = await fetch("./generate_text_stream", {
@@ -116,3 +153,4 @@ function handleKeyPress(event) {
 }
 
 window.onload = () => addMessage("This session is: " + session_uuid, 'bot');
+generateSession()