diff --git a/src/api/toolchain_routes.py b/src/api/toolchain_routes.py
index 666708a..20e58e8 100644
--- a/src/api/toolchain_routes.py
+++ b/src/api/toolchain_routes.py
@@ -400,6 +400,8 @@ async def _handle_issues(payload: Dict[str, Any]) -> None:
 
 async def _handle_issue_comment(payload: Dict[str, Any]) -> None:
     """处理 issue_comment 事件：CI 失败关键词 → 通知 PR 作者。"""
+    # DEBUG: log full payload for investigation
+    logger.info("issue_comment FULL PAYLOAD: %s", json.dumps(payload, ensure_ascii=False)[:3000])
     comment = payload.get("comment")
     if not comment or not isinstance(comment, dict):
         logger.warning("issue_comment event missing comment field, skipping")