diff --git a/src/connection/protocol.ts b/src/connection/protocol.ts
index 718a789..b753602 100644
--- a/src/connection/protocol.ts
+++ b/src/connection/protocol.ts
@@ -29,6 +29,8 @@ export type BackendMessageType =
   | 'create_pty'
   | 'kill_pty'
   | 'resize'
+  | 'ensure_pty'
+  | 'request_replay'
   | 'list_directories'
   | 'list_sessions';
 
diff --git a/src/main.ts b/src/main.ts
index 007ac36..514c4bd 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -81,13 +81,16 @@ class ClaudeCliProxy {
         case 'create_pty':
           this.handleCreatePty(msg.payload as CreatePtyPayload);
           break;
+        case 'ensure_pty':
+          this.handleEnsurePty(msg.payload as CreatePtyPayload);
+          break;
         case 'kill_pty':
           this.handleKillPty(msg.payload as KillPtyPayload);
           break;
         case 'resize':
           this.handleResize(msg.payload as ResizePayload);
           break;
-        case 'request_replay' as any: {
+        case 'request_replay': {
           const { chatId } = msg.payload as { chatId: string };
           const replay = this.pty.getReplayBuffer(chatId);
           if (replay) {
@@ -116,23 +119,15 @@ class ClaudeCliProxy {
     const activePtys = new Set(this.pty.listPtys());
     const chatIds = new Set(payload.chats.map((c) => c.id));
 
+    // Send replay + pty_ready for already running PTYs
+    // PTYs for new chats will be created via ensure_pty from frontend
     for (const chat of payload.chats) {
       if (activePtys.has(chat.id)) {
-        // PTY exists — send replay + ready
         const replay = this.pty.getReplayBuffer(chat.id);
         if (replay) {
           this.ws.sendBinary(encodeBinaryFrame(DIR_PTY_OUTPUT, chat.id, replay));
         }
         this.ws.send({ type: 'pty_ready', payload: { chatId: chat.id } });
-      } else if (chat.workDir) {
-        // PTY not running — create it
-        this.handleCreatePty({
-          chatId: chat.id,
-          dir: chat.workDir,
-          resumeSessionId: chat.sessionId ?? undefined,
-          cols: chat.cols ?? 120,
-          rows: chat.rows ?? 40,
-        });
       }
     }
 
@@ -166,6 +161,21 @@ class ClaudeCliProxy {
     this.ws.send({ type: 'pty_ready', payload: { chatId: payload.chatId } });
   }
 
+  private handleEnsurePty(payload: CreatePtyPayload): void {
+    if (this.pty.hasPty(payload.chatId)) {
+      // PTY already exists — resize to match client, send replay + ready
+      this.pty.resizePty(payload.chatId, payload.cols, payload.rows);
+      const replay = this.pty.getReplayBuffer(payload.chatId);
+      if (replay) {
+        this.ws.sendBinary(encodeBinaryFrame(DIR_PTY_OUTPUT, payload.chatId, replay));
+      }
+      this.ws.send({ type: 'pty_ready', payload: { chatId: payload.chatId } });
+    } else {
+      // PTY doesn't exist — create with client's dimensions
+      this.handleCreatePty(payload);
+    }
+  }
+
   private handleKillPty(payload: KillPtyPayload): void {
     this.pty.killPty(payload.chatId);
     this.ws.send({ type: 'pty_closed', payload: { chatId: payload.chatId, exitCode: 0 } });