[Responses] Fix empty-prompt routing for token-first chat encoders (kimi_k3, inkling) (#35486)

Co-authored-by: Xinyuan Tong <115166877+JustinTong0323@users.noreply.github.com> Co-authored-by: Xinyuan Tong <xinyuantong.cs@gmail.com>
2026-09-11 01:06:20 +00:00
parent 9df72e8f5a
commit ad7f57c9ea
4 changed files with 62 additions and 26 deletions
@@ -622,6 +622,36 @@ class MultimodalRequestTestCase(CustomTestCase):
        )
        self.assertEqual(captured["adapted_request"].modalities, ["image"])

+    def test_multimodal_token_first_specs_route_through_prompt_ids(self):
+        """Bug regression: token-first encoders leave prompt == "" with
+        non-empty prompt_ids; forwarding the empty text 400s in
+        _tokenize_texts, so the multimodal branch must forward prompt_ids."""
+        for spec in ("inkling", "kimi_k3"):
+            with self.subTest(spec=spec):
+                serving = make_serving(is_multimodal=True)
+                serving.chat_encoding_spec = spec
+                serving._process_messages = Mock(
+                    return_value=MessageProcessingResult(
+                        prompt="",
+                        prompt_ids=[4, 5, 6],
+                        image_data=None,
+                        audio_data=None,
+                        video_data=None,
+                        modalities=[],
+                        stop=[],
+                    )
+                )
+                request = ResponsesRequest(model="x", input="hi", store=False)
+
+                _, request_prompts, engine_prompts, _ = asyncio.run(
+                    serving._make_request(
+                        request, None, serving.tokenizer_manager.tokenizer
+                    )
+                )
+
+                self.assertEqual(engine_prompts, [[4, 5, 6]])
+                self.assertEqual(request_prompts, [[4, 5, 6]])
+

 class OutputItemsTestCase(CustomTestCase):
    def setUp(self):