diff --git a/.github/workflows/cd.yml b/.github/workflows/cd.yml
index de280a1..51ea357 100644
--- a/.github/workflows/cd.yml
+++ b/.github/workflows/cd.yml
@@ -90,4 +90,4 @@ jobs:
           echo "❌ Health check failed. Rolling back..."
           docker rm -f node-app-$TARGET_COLOR || true
           exit 1
-          EOF
\ No newline at end of file
+          EOF
diff --git a/public/client-test.html b/public/client-test.html
index bbe90a3..4545170 100644
--- a/public/client-test.html
+++ b/public/client-test.html
@@ -2,84 +2,97 @@
 <html lang="en">
 <head>
   <meta charset="UTF-8" />
-  <title>Socket.IO 채팅</title>
+  <title>Socket.IO 채팅 (JWT 토큰 입력)</title>
   <script src="https://cdn.socket.io/4.6.1/socket.io.min.js"></script>
 </head>
 <body>
-  <h2>실시간 채팅</h2>
+  <h2>실시간 채팅 (JWT 인증)</h2>
 
   <div>
-    <label for="senderIdInput">사용자 ID 입력:</label>
-    <input type="text" id="senderIdInput" placeholder="사용자 ID를 입력하세요" />
-    <button id="joinBtn">채팅방 입장</button>
+    <label for="tokenInput">JWT 토큰 입력:</label>
+    <input type="text" id="tokenInput" placeholder="JWT 토큰을 입력하세요" style="width: 400px;" />
+    <button id="connectBtn">서버 연결 및 채팅방 입장</button>
   </div>
-  
-  <div id="chatroom" style="display:none;">
+
+  <div id="chatroom" style="display:none; margin-top: 20px;">
     <div id="messages" style="border:1px solid #ccc; height:300px; overflow-y:scroll; margin-bottom:10px; padding:5px;"></div>
 
     <input type="text" id="messageInput" placeholder="메시지 입력 (최대 255자)" maxlength="255" style="width:60%;" />
     <input type="file" id="imageInput" accept="image/*" />
     <button id="sendBtn">전송</button>
   </div>
-  
+
   <script>
-    // 서버 소켓 연결 (URL 바꾸기)
-    const socket = io('http://localhost:3000');
+    let socket = null;
     const chatroomId = '1'; // 실제 채팅방 아이디 동적으로 받아야 함
 
-    let senderId = null;
+    const tokenInput = document.getElementById('tokenInput');
+    const connectBtn = document.getElementById('connectBtn');
 
-    const joinBtn = document.getElementById('joinBtn');
-    const senderIdInput = document.getElementById('senderIdInput');
     const chatroomDiv = document.getElementById('chatroom');
-
     const messagesDiv = document.getElementById('messages');
     const messageInput = document.getElementById('messageInput');
     const imageInput = document.getElementById('imageInput');
     const sendBtn = document.getElementById('sendBtn');
 
-    joinBtn.addEventListener('click', () => {
-      const inputVal = senderIdInput.value.trim();
-      if (!inputVal) {
-        alert('사용자 ID를 입력해주세요.');
+    connectBtn.addEventListener('click', () => {
+      const token = tokenInput.value.trim();
+      if (!token) {
+        alert('JWT 토큰을 입력해주세요.');
         return;
       }
-      senderId = inputVal;
 
-      // 채팅방 입장
-      socket.emit('join', chatroomId);
-
-      // UI 변경
-      senderIdInput.disabled = true;
-      joinBtn.disabled = true;
-      chatroomDiv.style.display = 'block';
-    });
-
-    // 메시지 받기
-    socket.on('chat message', (msg) => {
-      const div = document.createElement('div');
-      div.style.borderBottom = '1px solid #eee';
-      div.style.padding = '5px';
-
-      let content = `<b>사용자 ${msg.senderId}:</b> ${msg.content || ''}`;
-      if (msg.imageUrl) {
-        content += `<br><img src="${msg.imageUrl}" alt="이미지" style="max-width:200px; max-height:200px;" />`;
+      // 기존 연결 있으면 끊기
+      if (socket) {
+        socket.disconnect();
       }
-      div.innerHTML = content;
-
-      messagesDiv.appendChild(div);
-      messagesDiv.scrollTop = messagesDiv.scrollHeight;
-    });
 
-    // 에러 받기
-    socket.on('error', (err) => {
-      alert('에러: ' + err.message);
+      // 소켓 연결 (토큰을 auth에 담아 보냄)
+      socket = io('http://localhost:3000', {
+        auth: {
+          token: token,
+        }
+      });
+
+      socket.on('connect', () => {
+        console.log('서버 연결됨, 채팅방 입장');
+        socket.emit('join', chatroomId);
+
+        chatroomDiv.style.display = 'block';
+        tokenInput.disabled = true;
+        connectBtn.disabled = true;
+      });
+
+      socket.on('chat message', (msg) => {
+        const div = document.createElement('div');
+        div.style.borderBottom = '1px solid #eee';
+        div.style.padding = '5px';
+
+        let content = `<b>사용자 ${msg.senderId}:</b> ${msg.content || ''}`;
+        if (msg.imageUrl) {
+          content += `<br><img src="${msg.imageUrl}" alt="이미지" style="max-width:200px; max-height:200px;" />`;
+        }
+        div.innerHTML = content;
+
+        messagesDiv.appendChild(div);
+        messagesDiv.scrollTop = messagesDiv.scrollHeight;
+      });
+
+      socket.on('error', (err) => {
+        alert('에러: ' + err.message);
+      });
+
+      socket.on('disconnect', () => {
+        alert('서버 연결이 끊겼습니다.');
+        chatroomDiv.style.display = 'none';
+        tokenInput.disabled = false;
+        connectBtn.disabled = false;
+      });
     });
 
-    // 전송 버튼 클릭
     sendBtn.addEventListener('click', () => {
-      if (!senderId) {
-        alert('먼저 사용자 ID를 입력하고 채팅방에 입장하세요.');
+      if (!socket || !socket.connected) {
+        alert('서버에 연결되어 있지 않습니다.');
         return;
       }
 
@@ -102,7 +115,6 @@ <h2>실시간 채팅</h2>
 
           socket.emit('chat message', {
             chatroomId,
-            senderId,
             content,
             imageBase64: base64Image,
           });
@@ -111,7 +123,6 @@ <h2>실시간 채팅</h2>
       } else {
         socket.emit('chat message', {
           chatroomId,
-          senderId,
           content,
         });
       }
diff --git a/src/chat/dto/chatroom.dto.js b/src/chat/dto/chatroom.dto.js
index 84841b2..bb2a656 100644
--- a/src/chat/dto/chatroom.dto.js
+++ b/src/chat/dto/chatroom.dto.js
@@ -21,7 +21,9 @@ export class ChatroomListResponseDto {
     this.artist_profile_image = room.artist.profileImage;
     this.request_id = room.request.id;
     this.request_title = room.request.commission.title;
-    this.last_message = room.chatMessages[0]?.content || null;
+    // 이미지가 있으면 이미지 URL, 없으면 텍스트 content
+    const lastMsg = room.chatMessages[0];
+    this.last_message = lastMsg?.imageUrl || lastMsg?.content || null;
     this.last_message_time = room.chatMessages[0]?.createdAt || null;
     this.has_unread = unreadCount;
   }
diff --git a/src/chat/repository/chat.repository.js b/src/chat/repository/chat.repository.js
index 1132868..f119503 100644
--- a/src/chat/repository/chat.repository.js
+++ b/src/chat/repository/chat.repository.js
@@ -48,20 +48,27 @@ export const ChatRepository = {
   },
 
   async markAsRead(accountId, messageId) {
-    return await prisma.chatMessageRead.upsert({
+    const existing = await prisma.chatMessageRead.findFirst({
       where: {
-        messageId_accountId: {
-          messageId: BigInt(messageId),
-          accountId: BigInt(accountId),
-        },
-      },
-      update: { read: true },
-      create: {
         messageId: BigInt(messageId),
         accountId: BigInt(accountId),
-        read: true,
       },
     });
+
+    if (existing) {
+      return await prisma.chatMessageRead.update({
+        where: { id: existing.id },
+        data: { read: true },
+      });
+    } else {
+      return await prisma.chatMessageRead.create({
+        data: {
+          messageId: BigInt(messageId),
+          accountId: BigInt(accountId),
+          read: true,
+        },
+      });
+    }
   },
 
   async isMessageRead(accountId, messageId) {
diff --git a/src/chat/repository/chatroom.repository.js b/src/chat/repository/chatroom.repository.js
index 3d66e4b..b0a1e36 100644
--- a/src/chat/repository/chatroom.repository.js
+++ b/src/chat/repository/chatroom.repository.js
@@ -23,7 +23,8 @@ export const ChatroomRepository = {
   },
 
   async findChatroomsByUser(consumerId) {
-    return prisma.chatroom.findMany({
+    // 1. 채팅방 기본 정보 + 마지막 메시지(내용, 생성시간, id) 조회
+    const chatrooms = await prisma.chatroom.findMany({
       where: { consumerId },
       include: {
         artist: {
@@ -38,7 +39,7 @@ export const ChatroomRepository = {
             id: true,
             commission: {
               select: {
-                title: true
+                title: true,
               }
             }
           }
@@ -47,12 +48,46 @@ export const ChatroomRepository = {
           orderBy: { createdAt: "desc" },
           take: 1,
           select: {
+            id: true,
             content: true,
-            createdAt: true
+            createdAt: true,
           }
         }
       }
     });
+
+    // 2. 마지막 메시지 ID 목록 수집
+    const messageIds = chatrooms
+      .map(room => room.chatMessages[0]?.id)
+      .filter(Boolean); // null 제외
+
+    if (messageIds.length === 0) {
+      return chatrooms;
+    }
+
+    // 3. 메시지 ID로 이미지 URL 조회
+    const images = await prisma.image.findMany({
+      where: {
+        target: "chat_messages",
+        targetId: { in: messageIds },
+      },
+    });
+
+    // 4. 이미지 URL 매핑 (messageId -> imageUrl)
+    const imageMap = {};
+    images.forEach(img => {
+      imageMap[img.targetId.toString()] = img.imageUrl;
+    });
+
+    // 5. 채팅방 객체에 이미지 URL 병합
+    chatrooms.forEach(room => {
+      const msg = room.chatMessages[0];
+      if (msg) {
+        msg.imageUrl = imageMap[msg.id.toString()] || null;
+      }
+    });
+
+    return chatrooms;
   },
 
   async softDeleteChatrooms(chatroomIds, userType, userId) {
diff --git a/src/chat/socket/socket.js b/src/chat/socket/socket.js
index 3d37e47..54e0842 100644
--- a/src/chat/socket/socket.js
+++ b/src/chat/socket/socket.js
@@ -31,7 +31,8 @@ export default function setupSocket(server) {
 
     // 채팅방 join
     socket.on("join", async (chatroomId) => {
-      socket.join(chatroomId);
+      const room = String(chatroomId);
+      socket.join(room);
       console.log(`User ${socket.user.userId} joined chatroom ${chatroomId}`);
 
       try {
@@ -70,7 +71,8 @@ export default function setupSocket(server) {
     });
 
     // 메시지 수신
-    socket.on("chat message", async ({ chatroomId, senderId, content, imageBase64 }) => {
+    socket.on("chat message", async ({ chatroomId, content, imageBase64 }) => {
+      const room = String(chatroomId);
       try {
         if (content && content.length > 255) {
           socket.emit("error", { message: "메시지 길이는 255자를 초과할 수 없습니다." });
@@ -81,19 +83,18 @@ export default function setupSocket(server) {
 
         // 이미지 처리
         if (imageBase64) {
-          const buffer = Buffer.from(imageBase64, 'base64');
-          imageUrl = await uploadToS3({
-            buffer,
-            folderName: "messages",
-            extension: "png"
-          });
+          const base64Data = imageBase64.replace(/^data:image\/\w+;base64,/, '');
+          const buffer = Buffer.from(base64Data, 'base64');
+          console.log("Buffer length:", buffer.length);
+          console.log("Is Buffer:", Buffer.isBuffer(buffer));
+          imageUrl = await uploadToS3(buffer, "messages", "png");
         }
 
         // 메시지 저장
         const savedMessage = await prisma.chatMessage.create({
           data: {
             chatroomId: BigInt(chatroomId),
-            senderId: BigInt(senderId),
+            senderId: BigInt(socket.user.accountId),
             content,
           },
         });
@@ -119,7 +120,7 @@ export default function setupSocket(server) {
           createdAt: savedMessage.createdAt,
         }));
 
-        io.to(chatroomId).emit("chat message", safeMessage);
+        io.to(room).emit("chat message", safeMessage);
 
       } catch (err) {
         console.error("Socket message error:", err);
diff --git a/src/common/swagger/chat.json b/src/common/swagger/chat.json
index 6fb579b..be9eb95 100644
--- a/src/common/swagger/chat.json
+++ b/src/common/swagger/chat.json
@@ -34,14 +34,17 @@
                   "type": "object",
                   "properties": {
                     "resultType": { "type": "string", "example": "SUCCESS" },
-                    "error": { "type": "object", "nullable": true },
+                    "error": { "type": "object", "nullable": true, "example": null },
                     "success": {
                       "type": "object",
                       "properties": {
-                        "id": { "type": "integer", "example": 10 },
-                        "consumerId": { "type": "integer", "example": 1 },
-                        "artistId": { "type": "integer", "example": 2 },
-                        "requestId": { "type": "integer", "example": 3 }
+                        "id": { "type": "string", "example": "1" },
+                        "consumerId": { "type": "string", "example": "1" },
+                        "artistId": { "type": "string", "example": "1" },
+                        "requestId": { "type": "string", "example": "1" },
+                        "hiddenArtist": { "type": "boolean", "example": false },
+                        "hiddenConsumer": { "type": "boolean", "example": false },
+                        "createdAt": { "type": "string", "format": "date-time", "example": "2025-08-07T15:35:42.375Z" }
                       }
                     }
                   }
