diff --git a/src/app_controller.py b/src/app_controller.py
index 61b8dde..8ad31ea 100644
--- a/src/app_controller.py
+++ b/src/app_controller.py
@@ -138,6 +138,7 @@ class AppController:
   self.active_tickets: List[Dict[str, Any]] = []
   self.mma_streams: Dict[str, str] = {}
   self._worker_status: Dict[str, str] = {}  # stream_id -> "running" | "completed" | "failed" | "killed"
+  self.MAX_STREAM_SIZE: int = 10 * 1024  # 10KB max per stream
   self._pending_patch_text: Optional[str] = None
   self._pending_patch_files: List[str] = []
   self._show_patch_modal: bool = False
@@ -401,6 +402,8 @@ class AppController:
        if stream_id not in self.mma_streams: self.mma_streams[stream_id] = ""
        if stream_id not in self._worker_status: self._worker_status[stream_id] = "running"
        self.mma_streams[stream_id] += text
+       if len(self.mma_streams[stream_id]) > self.MAX_STREAM_SIZE:
+        self.mma_streams[stream_id] = self.mma_streams[stream_id][-self.MAX_STREAM_SIZE:]
       else:
        self.mma_streams[stream_id] = text
        if stream_id in self._worker_status and self._worker_status[stream_id] == "running":