fix: default reasoning context for codex proxy Responses API (#380)

* fix: set langgraph and codex proxy runtime defaults

* fix: address runtime default review feedback

* fix: drop langgraph dev env defaults per maintainer review

langgraph dev patches DATABASE_URI/REDIS_URI itself via patch_environment,
so the reported KeyError cannot come from this flow; the env defaults added
here were unnecessary. Scope the PR back to the codex proxy reasoning
context fix only.

---------

Co-authored-by: Xi Zhang <106144707+X-iZhang@users.noreply.github.com>

EvoScientist/llm/models.py

@@ -728,6 +728,13 @@ def get_chat_model(
         elif _responses_api_setting == "true":
             kwargs["use_responses_api"] = True
 
+    if _is_openai_proxy and kwargs.get("use_responses_api") is True:
+        reasoning = kwargs.setdefault("reasoning", {})
+        if isinstance(reasoning, dict):
+            reasoning = dict(reasoning)
+            reasoning.setdefault("context", "all_turns")
+            kwargs["reasoning"] = reasoning
+
     if _uses_native_deepseek:
         chat_model = EvoChatDeepSeek(model=model_id, **kwargs)
     else:

tests/test_llm.py

@@ -2672,7 +2672,11 @@ class TestAutoConfig:
         assert call_kwargs["base_url"] == "http://127.0.0.1:8000/codex/v1"
         assert call_kwargs["api_key"] == "ccproxy-oauth"
         # ccproxy uses the Responses API, so reasoning configuration is valid.
-        assert call_kwargs["reasoning"] == {"effort": "high", "summary": "auto"}
+        assert call_kwargs["reasoning"] == {
+            "effort": "high",
+            "summary": "auto",
+            "context": "all_turns",
+        }
         # Proxy mode: Responses API (bypasses format chain), streaming ON
         assert call_kwargs["use_responses_api"] is True
         assert "streaming" not in call_kwargs
@@ -2729,6 +2733,7 @@ class TestAutoConfig:
         assert headers["User-Agent"].startswith("codex_cli_rs/0.144.1")
         mock_installed_version.assert_called_once_with()
         assert mock_init.call_args[1]["reasoning"]["effort"] == "xhigh"
+        assert mock_init.call_args[1]["reasoning"]["context"] == "all_turns"
 
     @patch("EvoScientist.llm.models.init_chat_model")
     def test_openai_ccproxy_codex_client_version_env(self, mock_init, monkeypatch):
@@ -2802,6 +2807,66 @@ class TestAutoConfig:
         assert headers["version"] == "9.9.9"
         assert headers["User-Agent"].startswith("codex_cli_rs/9.9.9")
 
+    @patch("EvoScientist.llm.models.init_chat_model")
+    def test_openai_ccproxy_codex_reasoning_context_respects_caller(
+        self, mock_init, monkeypatch
+    ):
+        """Caller-supplied reasoning.context is not overridden."""
+        mock_init.return_value = "mock_model"
+        monkeypatch.setenv("OPENAI_BASE_URL", "http://127.0.0.1:8000/codex/v1")
+        monkeypatch.setenv("OPENAI_API_KEY", "ccproxy-oauth")
+        reasoning = {"effort": "low", "context": "previous_response_id"}
+
+        get_chat_model(
+            "gpt-5.5",
+            provider="openai",
+            reasoning=reasoning,
+        )
+
+        assert mock_init.call_args[1]["reasoning"] == {
+            "effort": "low",
+            "context": "previous_response_id",
+        }
+        assert mock_init.call_args[1]["reasoning"] is not reasoning
+        assert reasoning == {"effort": "low", "context": "previous_response_id"}
+
+    @patch("EvoScientist.llm.models.init_chat_model")
+    def test_openai_ccproxy_codex_reasoning_context_requires_responses_api(
+        self, mock_init, monkeypatch
+    ):
+        """Responses-only reasoning.context is not sent when Chat Completions is forced."""
+        mock_init.return_value = "mock_model"
+        monkeypatch.setenv("OPENAI_BASE_URL", "http://127.0.0.1:8000/codex/v1")
+        monkeypatch.setenv("OPENAI_API_KEY", "ccproxy-oauth")
+        monkeypatch.delenv("EVOSCIENTIST_USE_RESPONSES_API", raising=False)
+
+        get_chat_model(
+            "gpt-5.5",
+            provider="openai",
+            use_responses_api=False,
+            reasoning={"effort": "low"},
+        )
+
+        call_kwargs = mock_init.call_args[1]
+        assert call_kwargs["use_responses_api"] is False
+        assert call_kwargs["reasoning"] == {"effort": "low"}
+
+    @patch("EvoScientist.llm.models.init_chat_model")
+    def test_openai_ccproxy_codex_env_false_drops_reasoning(
+        self, mock_init, monkeypatch
+    ):
+        """The global Chat Completions override still removes reasoning entirely."""
+        mock_init.return_value = "mock_model"
+        monkeypatch.setenv("OPENAI_BASE_URL", "http://127.0.0.1:8000/codex/v1")
+        monkeypatch.setenv("OPENAI_API_KEY", "ccproxy-oauth")
+        monkeypatch.setenv("EVOSCIENTIST_USE_RESPONSES_API", "false")
+
+        get_chat_model("gpt-5.5", provider="openai")
+
+        call_kwargs = mock_init.call_args[1]
+        assert call_kwargs["use_responses_api"] is False
+        assert "reasoning" not in call_kwargs
+
     @patch("EvoScientist.llm.models.init_chat_model")
     def test_openai_ccproxy_codex_none_headers(self, mock_init, monkeypatch):
         """An explicit default_headers=None is normalized before gap-filling."""