diff --git a/server/ai/client.js b/server/ai/client.js
index fce9cee..28ae2c8 100644
--- a/server/ai/client.js
+++ b/server/ai/client.js
@@ -1,12 +1,18 @@
 // DeepSeek API 客户端
 const DEEPSEEK_API_KEY = process.env.DEEPSEEK_API_KEY || '';
 
-async function callDeepSeek(messages, temperature = 0.1) {
+function sanitizeUserId(username) {
+  return username.replace(/[^a-zA-Z0-9\-_]/g, '_').substring(0, 64) || 'anon';
+}
+
+async function callDeepSeek(messages, temperature = 0.1, userId = '') {
   console.log('🤖 调用 DeepSeek...');
-  const res = await fetch('https://api.deepseek.com/chat/completions', {
+  var body = { model: 'deepseek-v4-flash', messages: messages, temperature: temperature, stream: false };
+  if (userId) body.user_id = sanitizeUserId(userId);
+  var res = await fetch('https://api.deepseek.com/chat/completions', {
     method: 'POST',
-    headers: { 'Content-Type': 'application/json', 'Authorization': `Bearer ${DEEPSEEK_API_KEY}` },
-    body: JSON.stringify({ model: 'deepseek-v4-flash', messages, temperature, stream: false })
+    headers: { 'Content-Type': 'application/json', 'Authorization': 'Bearer ' + DEEPSEEK_API_KEY },
+    body: JSON.stringify(body)
   });
   const data = await res.json();
   if (!data.choices || !data.choices[0]) {
diff --git a/server/handlers.js b/server/handlers.js
index 3c32f31..5189fff 100644
--- a/server/handlers.js
+++ b/server/handlers.js
@@ -170,7 +170,7 @@ function handleAIResult(aiResult, roomId, username, originalText, attachments) {
   if (aiResult.action === 'query') {
     const purchaseData = db.prepare('SELECT item, amount, payment_method, status FROM purchases WHERE room_id = ? ORDER BY created_at DESC').all(roomId).map(p => p.item + ' ' + p.amount + ' ' + (p.payment_method||'') + ' ' + p.status).join('\n');
     const summaryPrompt = '\u6839\u636e\u4ee5\u4e0b\u91c7\u8d2d\u8bb0\u5f55\uff0c\u7528\u81ea\u7136\u8bed\u8a00\u56de\u7b54\u7528\u6237\u67e5\u8be2"' + originalText + '"' + '\u3002\u91c7\u8d2d\u8bb0\u5f55\uff1a\n' + (purchaseData || '\u6682\u65e0\u8bb0\u5f55');
-    callDeepSeekForSummary(summaryPrompt).then(reply => { storeAndBroadcastText(roomId, '\u5c0f\u8d22', reply); addToHistory(roomId, 'assistant', reply); });
+    callDeepSeekForSummary(summaryPrompt, username).then(reply => { storeAndBroadcastText(roomId, '小财', reply); addToHistory(roomId, 'assistant', reply); });
     return;
   }
 
@@ -181,13 +181,13 @@ function handleAIResult(aiResult, roomId, username, originalText, attachments) {
   }
 }
 
-async function callDeepSeekForSummary(prompt) {
+async function callDeepSeekForSummary(prompt, userId) {
   const { callDeepSeek } = require('./ai/client');
   const messages = [
-    { role: 'system', content: '\u4f60\u662f\u4e00\u4e2a\u8d22\u52a1\u52a9\u624b\uff0c\u8bf7\u6839\u636e\u91c7\u8d2d\u8bb0\u5f55\u751f\u6210\u7b80\u6d01\u56de\u590d\u3002' },
+    { role: 'system', content: '你是一个财务助手，请根据采购记录生成简洁回复。' },
     { role: 'user', content: prompt }
   ];
-  return callDeepSeek(messages, 0.3);
+  return callDeepSeek(messages, 0.3, userId);
 }
 
 module.exports = {
diff --git a/server/routes/messages.js b/server/routes/messages.js
index 4945ab4..e6488f0 100644
--- a/server/routes/messages.js
+++ b/server/routes/messages.js
@@ -63,7 +63,7 @@ async function analyzeWithDeepSeek(text, historyMessages, username, isAdmin, roo
     ...historyMessages.slice(-30),
     { role: 'user', content: `${username}: ${text}` }
   ];
-  const content = await callDeepSeek(messages, 0.1);
+  const content = await callDeepSeek(messages, 0.1, username);
   console.log('🤖 AI 返回:', content);
   try {
     const parsed = JSON.parse(content.replace(/```json|```/g, '').trim());