diff --git a/python/sglang/lang/chat_template.py b/python/sglang/lang/chat_template.py
index 9dc817818..45f5825ce 100644
--- a/python/sglang/lang/chat_template.py
+++ b/python/sglang/lang/chat_template.py
@@ -232,9 +232,15 @@ register_chat_template(
         name="c4ai-command-r",
         default_system_prompt=None,
         role_prefix_and_suffix={
-            "system": ("<|START_OF_TURN_TOKEN|><|SYSTEM_TOKEN|>", "<|END_OF_TURN_TOKEN|>"),
+            "system": (
+                "<|START_OF_TURN_TOKEN|><|SYSTEM_TOKEN|>",
+                "<|END_OF_TURN_TOKEN|>",
+            ),
             "user": ("<|START_OF_TURN_TOKEN|><|USER_TOKEN|>", "<|END_OF_TURN_TOKEN|>"),
-            "assistant": ("<|START_OF_TURN_TOKEN|><|CHATBOT_TOKEN|>", "<|END_OF_TURN_TOKEN|>"),
+            "assistant": (
+                "<|START_OF_TURN_TOKEN|><|CHATBOT_TOKEN|>",
+                "<|END_OF_TURN_TOKEN|>",
+            ),
         },
         style=ChatTemplateStyle.PLAIN,
     )
diff --git a/python/sglang/lang/interpreter.py b/python/sglang/lang/interpreter.py
index 87d85de30..ebc65a0e0 100644
--- a/python/sglang/lang/interpreter.py
+++ b/python/sglang/lang/interpreter.py
@@ -1,6 +1,7 @@
 """The interpreter that executes SGL programs"""
 
 import asyncio
+import contextvars
 import multiprocessing
 import queue
 import threading
@@ -9,7 +10,6 @@ from concurrent.futures import ThreadPoolExecutor
 from contextlib import contextmanager
 from typing import Any, Callable, Dict, List, Optional, Union
 
-import contextvars
 import tqdm
 
 from sglang.global_config import global_config
@@ -222,7 +222,10 @@ class StreamExecutor:
 
             def _run_worker_in_context():
                 self._thread_worker_func()
-            self.worker = threading.Thread(target=contextvars.copy_context().run, args=(_run_worker_in_context, ))
+
+            self.worker = threading.Thread(
+                target=contextvars.copy_context().run, args=(_run_worker_in_context,)
+            )
             self.worker.start()
 
         # For streaming
@@ -265,12 +268,11 @@ class StreamExecutor:
         self,
         number: int,
         position_ids_offset: Optional[List[int]] = None,
-        copy: bool = False,
     ):
-        if number > 1 or copy:
+        if number > 1:
             self.submit(SglCommitLazy())
-            self.sync()
 
+        self.sync()
         number = int(number)
 
         exes = [
@@ -656,16 +658,15 @@ class ProgramState:
         self,
         number: int = 1,
         position_ids_offset: Optional[List[int]] = None,
-        copy: bool = False,
     ):
-        stream_executors = self.stream_executor.fork(number, position_ids_offset, copy)
+        stream_executors = self.stream_executor.fork(number, position_ids_offset)
         states = [ProgramState(x) for x in stream_executors]
         state_group = ProgramStateGroup(states, self)
         return state_group
 
     @contextmanager
     def copy(self, position_ids_offset: Optional[List[int]] = None):
-        state_group = self.fork(1, position_ids_offset, True)
+        state_group = self.fork(1, position_ids_offset)
         try:
             yield state_group[0]
         finally:
diff --git a/python/sglang/srt/managers/detokenizer_manager.py b/python/sglang/srt/managers/detokenizer_manager.py
index 595355425..436d91525 100644
--- a/python/sglang/srt/managers/detokenizer_manager.py
+++ b/python/sglang/srt/managers/detokenizer_manager.py
@@ -42,7 +42,9 @@ class DetokenizerManager:
                 output_strs = self.tokenizer.batch_decode(
                     output_tokens,
                     skip_special_tokens=recv_obj.skip_special_tokens[0],
-                    spaces_between_special_tokens=recv_obj.spaces_between_special_tokens[0],
+                    spaces_between_special_tokens=recv_obj.spaces_between_special_tokens[
+                        0
+                    ],
                 )
 
                 # Trim stop str