fix(api): forward extra_body.chat_template_kwargs on /v1/messages

lightllm/server/api_anthropic.py

@@ -76,6 +76,17 @@ def _anthropic_to_chat_request(anthropic_body: Dict[str, Any]) -> Tuple[Dict[str
         if "max_tokens" in anthropic_body:
             openai_dict["max_tokens"] = anthropic_body["max_tokens"]
 
+    # Forward LightLLM-specific fields nested under ``extra_body`` (OpenAI SDK
+    # convention) so clients hitting /v1/messages can reach ChatCompletionRequest
+    # options Anthropic's own schema does not expose — notably chat_template_kwargs
+    # for models with optional thinking modes (Qwen3, DeepSeek). Fields already
+    # produced by the Anthropic->OpenAI translation take precedence; unknown keys
+    # are silently dropped by Pydantic (extra='ignore').
+    extra_body = anthropic_body.get("extra_body")
+    if isinstance(extra_body, dict):
+        for k, v in extra_body.items():
+            openai_dict.setdefault(k, v)
+
     _UNKNOWN_FIELDS = {"extra_body", "metadata", "anthropic_version", "cache_control"}
     for key in list(openai_dict.keys()):
         if key in _UNKNOWN_FIELDS:

test/test_api/test_anthropic_extra_body.py

@@ -0,0 +1,75 @@
+"""Unit test for Anthropic -> OpenAI request translation with extra_body.
+
+Verifies that ``extra_body.chat_template_kwargs`` (and other backend-specific
+fields nested under ``extra_body`` per OpenAI SDK convention) survive the
+/v1/messages request translation, so clients can opt out of model-default
+thinking modes on engines that expose the toggle through
+ChatCompletionRequest.chat_template_kwargs.
+
+No server required — calls the pure translation helper directly.
+"""
+
+import pytest
+
+pytest.importorskip("litellm")
+
+from lightllm.server.api_anthropic import _anthropic_to_chat_request
+
+
+def _base_body():
+    return {
+        "model": "test-model",
+        "max_tokens": 32,
+        "messages": [{"role": "user", "content": "hi"}],
+    }
+
+
+def test_extra_body_chat_template_kwargs_forwarded():
+    body = _base_body()
+    body["extra_body"] = {"chat_template_kwargs": {"enable_thinking": False}}
+
+    chat_dict, _ = _anthropic_to_chat_request(body)
+
+    assert chat_dict.get("chat_template_kwargs") == {"enable_thinking": False}
+    assert "extra_body" not in chat_dict
+
+
+def test_extra_body_multiple_fields_forwarded():
+    body = _base_body()
+    body["extra_body"] = {
+        "chat_template_kwargs": {"enable_thinking": False},
+        "do_sample": False,
+        "top_k": 5,
+    }
+
+    chat_dict, _ = _anthropic_to_chat_request(body)
+
+    assert chat_dict.get("chat_template_kwargs") == {"enable_thinking": False}
+    assert chat_dict.get("do_sample") is False
+    assert chat_dict.get("top_k") == 5
+
+
+def test_top_level_openai_field_beats_extra_body_duplicate():
+    # If a field ends up in openai_dict via the Anthropic->OpenAI translation
+    # AND the same key appears in extra_body, the translation path wins.
+    body = _base_body()
+    body["temperature"] = 0.1  # translated by litellm -> openai_dict["temperature"] = 0.1
+    body["extra_body"] = {"temperature": 0.9}
+
+    chat_dict, _ = _anthropic_to_chat_request(body)
+
+    assert chat_dict.get("temperature") == 0.1
+
+
+def test_missing_extra_body_is_noop():
+    body = _base_body()
+    chat_dict, _ = _anthropic_to_chat_request(body)
+    assert "extra_body" not in chat_dict
+    assert "chat_template_kwargs" not in chat_dict
+
+
+def test_non_dict_extra_body_is_ignored():
+    body = _base_body()
+    body["extra_body"] = "not-a-dict"
+    chat_dict, _ = _anthropic_to_chat_request(body)
+    assert "extra_body" not in chat_dict