diff --git a/python/sglang/srt/managers/io_struct.py b/python/sglang/srt/managers/io_struct.py
index 8e53df335..f5279eb8d 100644
--- a/python/sglang/srt/managers/io_struct.py
+++ b/python/sglang/srt/managers/io_struct.py
@@ -53,6 +53,8 @@ class GenerateReqInput:
     # The modalities of the image data [image, multi-images, video]
     modalities: Optional[List[str]] = None
 
+    is_single: bool = True
+
     def post_init(self):
         if (self.text is None and self.input_ids is None) or (
             self.text is not None and self.input_ids is not None
@@ -194,6 +196,8 @@ class EmbeddingReqInput:
     # Dummy sampling params for compatibility
     sampling_params: Union[List[Dict], Dict] = None
 
+    is_single: bool = True
+
     def post_init(self):
         if (self.text is None and self.input_ids is None) or (
             self.text is not None and self.input_ids is not None