[Frontend] Apply request header overrides to chat completions (#35001)

Co-authored-by: Ye (Charlotte) Qi <ye.charlotte.qi@gmail.com>

python/sglang/srt/entrypoints/openai/serving_chat.py

@@ -61,6 +61,7 @@ from sglang.srt.entrypoints.openai.utils import (
     should_include_usage,
     to_openai_style_logprobs,
 )
+from sglang.srt.entrypoints.request_headers import apply_header_overrides
 from sglang.srt.environ import envs
 from sglang.srt.function_call.core_types import ToolCallItem
 from sglang.srt.function_call.function_call_parser import FunctionCallParser
@@ -1037,6 +1038,11 @@ class OpenAIServingChat(OpenAIServingBase):
             return_prompt_token_ids=request.return_prompt_token_ids
             or request.return_token_ids,
         )
+        if (
+            raw_request is not None
+            and envs.SGLANG_ENABLE_REQUEST_HEADER_OVERRIDES.get()
+        ):
+            apply_header_overrides(adapted_request, raw_request.headers)
 
         return adapted_request, request
 

test/registered/unit/entrypoints/openai/test_serving_chat.py

@@ -32,6 +32,7 @@ from sglang.srt.entrypoints.openai.serving_chat import (
     OpenAIServingChat,
     normalize_tool_content,
 )
+from sglang.srt.environ import envs
 from sglang.srt.function_call.kimik3_format import TOOLS_CLOSE
 from sglang.srt.managers.io_struct import GenerateReqInput
 from sglang.srt.parser.template_detection import ReasoningToggleConfig
@@ -100,6 +101,7 @@ class _MockTokenizerManager:
                     "prompt_tokens": 10,
                     "completion_tokens": 5,
                     "cached_tokens": 0,
+                    "weight_version": "test-version",
                     "finish_reason": {"type": "stop", "matched": None},
                     "output_token_logprobs": [(0.1, 1, "Test"), (0.2, 2, "response")],
                     "output_top_logprobs": None,
@@ -109,6 +111,7 @@ class _MockTokenizerManager:
 
         self.generate_request = Mock(return_value=_mock_generate())
         self.create_abort_task = Mock()
+        self.request_logger = Mock(log_requests=False, log_requests_level=0)
 
     def config_value(self, name: str):
         """The manager's overlay accessor: no control-plane update recorded."""
@@ -287,6 +290,53 @@ class ServingChatTestCase(unittest.TestCase):
             self.assertEqual(adapted.session_id, "session-1")
             self.assertEqual(processed, self.basic_req)
 
+    def test_chat_applies_pd_header_overrides(self):
+        request = ChatCompletionRequest(
+            model="x",
+            messages=[{"role": "user", "content": "Hi?"}],
+            rid="body-rid",
+            routed_dp_rank=3,
+            disagg_prefill_dp_rank=4,
+            priority=5,
+        )
+        self.fastapi_request.headers = {
+            "x-override-rid": "header-rid",
+            "x-override-bootstrap-host": "header-host",
+            "x-override-bootstrap-port": "8998",
+            "x-override-bootstrap-room": "456",
+            "x-override-conversation-id": "conversation-1",
+            "x-override-routed-dp-rank": "6",
+            "x-override-disagg-prefill-dp-rank": "7",
+            "x-override-priority": "8",
+        }
+        body = request.model_dump()
+
+        processed_messages = MessageProcessingResult(
+            "Test prompt", [1, 2, 3], None, None, [], [], None
+        )
+        with (
+            envs.SGLANG_ENABLE_REQUEST_HEADER_OVERRIDES.override(True),
+            patch.object(
+                self.chat, "_process_messages", return_value=processed_messages
+            ),
+        ):
+            response = get_or_create_event_loop().run_until_complete(
+                self.chat.handle_request(request, self.fastapi_request)
+            )
+
+        self.assertEqual(response.choices[0].message.content, "Test response")
+        adapted_request = self.tm.generate_request.call_args.args[0]
+        self.assertEqual(adapted_request.bootstrap_room, 456)
+        self.assertEqual(adapted_request.bootstrap_host, "header-host")
+        self.assertEqual(adapted_request.bootstrap_port, 8998)
+        self.assertEqual(adapted_request.rid, "header-rid")
+        self.assertEqual(adapted_request.conversation_id, "conversation-1")
+        self.assertEqual(adapted_request.routed_dp_rank, 6)
+        self.assertEqual(adapted_request.disagg_prefill_dp_rank, 7)
+        self.assertEqual(adapted_request.priority, 8)
+        self.assertEqual(request.model_dump(), body)
+        self.assertFalse(hasattr(request, "conversation_id"))
+
     def test_convert_to_internal_request_rejects_stream_token_ids(self):
         for field in ("return_prompt_token_ids", "return_token_ids"):
             req = ChatCompletionRequest(