diff --git a/python/sglang/api.py b/python/sglang/api.py
index 3a2f747be..9405606b7 100644
--- a/python/sglang/api.py
+++ b/python/sglang/api.py
@@ -78,6 +78,7 @@ def gen(
     choices: Optional[List[str]] = None,
     choices_method: Optional[ChoicesSamplingMethod] = None,
     regex: Optional[str] = None,
+    json_schema: Optional[str] = None,
 ):
     """Call the model to generate. See the meaning of the arguments in docs/en/sampling_params.md"""
 
@@ -114,6 +115,7 @@ def gen(
         return_text_in_logprobs,
         dtype,
         regex,
+        json_schema,
     )
 
 
diff --git a/python/sglang/lang/interpreter.py b/python/sglang/lang/interpreter.py
index 306d280c7..91f48456a 100644
--- a/python/sglang/lang/interpreter.py
+++ b/python/sglang/lang/interpreter.py
@@ -673,6 +673,7 @@ class StreamExecutor:
             "return_text_in_logprobs",
             "dtype",
             "regex",
+            "json_schema",
         ]:
             value = getattr(sampling_params, item, None)
             if value is not None:
diff --git a/python/sglang/lang/ir.py b/python/sglang/lang/ir.py
index 199a7ac7a..99a3e8e68 100644
--- a/python/sglang/lang/ir.py
+++ b/python/sglang/lang/ir.py
@@ -30,6 +30,7 @@ class SglSamplingParams:
     logprob_start_len: Optional[int] = (None,)
     top_logprobs_num: Optional[int] = (None,)
     return_text_in_logprobs: Optional[bool] = (None,)
+    json_schema: Optional[str] = None
 
     # for constrained generation, not included in to_xxx_kwargs
     dtype: Optional[str] = None
@@ -51,6 +52,7 @@ class SglSamplingParams:
             self.logprob_start_len,
             self.top_logprobs_num,
             self.return_text_in_logprobs,
+            self.json_schema,
         )
 
     def to_openai_kwargs(self):
@@ -121,6 +123,7 @@ class SglSamplingParams:
             "presence_penalty": self.presence_penalty,
             "ignore_eos": self.ignore_eos,
             "regex": self.regex,
+            "json_schema": self.json_schema,
         }
 
 
@@ -425,6 +428,7 @@ class SglGen(SglExpr):
         return_text_in_logprobs: Optional[bool] = None,
         dtype: Optional[type] = None,
         regex: Optional[str] = None,
+        json_schema: Optional[str] = None,
     ):
         """Call the model to generate. See the meaning of the arguments in docs/en/sampling_params.md"""
         super().__init__()
@@ -446,6 +450,7 @@ class SglGen(SglExpr):
             return_text_in_logprobs=return_text_in_logprobs,
             dtype=dtype,
             regex=regex,
+            json_schema=json_schema,
         )
 
     def __repr__(self):