diff --git a/tools/bridge_server.py b/tools/bridge_server.py
index 6829799..9fe5d87 100644
--- a/tools/bridge_server.py
+++ b/tools/bridge_server.py
@@ -27,7 +27,7 @@ import platform
 import sys
 
 PROTOCOL_VERSION = 1
-SERVER_BUILD = 8  # 2026-07-29: start/stop_notify 10s 超时 + connect subscribe 选项（OTA 净连接）
+SERVER_BUILD = 9  # 2026-07-29: StreamReader limit 64KiB→4MiB（OTA 144KB 请求行根因修复）
 
 EPD_SERVICE_UUID = "13187b10-eba9-a3ba-044e-83d3217d9a38"
 EPD_CHAR_UUID = "4b646063-6264-f3a7-8941-e65356ea82fe"
@@ -279,7 +279,9 @@ async def main():
     ap.add_argument("--port", type=int, default=8971)
     args = ap.parse_args()
     server = BridgeServer()
-    srv = await asyncio.start_server(server.handle, args.host, args.port)
+    # limit: OTA 镜像请求 ~145KB(hex)，远超默认 64KiB —— 必须显式放大（2026-07-29 根因）
+    srv = await asyncio.start_server(server.handle, args.host, args.port,
+                                     limit=4 * 1024 * 1024)
     print(f"[bridge] listening on {args.host}:{args.port} "
           f"(protocol v{PROTOCOL_VERSION}, platform {platform.system()})", flush=True)
     async with srv: