Support codex responses API

tests/test_core_flow.py

@@ -11,7 +11,7 @@ from unittest import mock
 from aituner.cli import main as cli_main
 from aituner.http_client import _auth_headers, _openai_url, _should_bypass_proxy
 from aituner.job import append_job, build_trial_job
-from aituner.llm import build_prompt, parse_proposal_text
+from aituner.llm import _extract_response_text, build_prompt, parse_proposal_text
 from aituner.search import ThresholdProbe, binary_search_max_feasible
 from aituner.slo import RequestOutcome, evaluate_request, summarize_evaluations
 from aituner.spec import (
@@ -242,6 +242,7 @@ class CoreFlowTests(unittest.TestCase):
                         "",
                         "[model_providers.ipads]",
                         'base_url = "http://codex.example/v1"',
+                        'wire_api = "responses"',
                     ]
                 ),
                 encoding="utf-8",
@@ -250,8 +251,24 @@ class CoreFlowTests(unittest.TestCase):
                 endpoint = LLMEndpointSpec.from_dict({"provider": "codex", "model": "gpt-5.4"})
             self.assertEqual(endpoint.provider, "codex")
             self.assertEqual(endpoint.base_url, "http://codex.example/v1")
+            self.assertEqual(endpoint.wire_api, "responses")
             self.assertEqual(endpoint.api_key_env, "OPENAI_API_KEY")
 
+    def test_extract_response_text_supports_responses_api_output(self) -> None:
+        text = _extract_response_text(
+            {
+                "output": [
+                    {
+                        "type": "message",
+                        "content": [
+                            {"type": "output_text", "text": '{"diagnosis":"ok"}'}
+                        ],
+                    }
+                ]
+            }
+        )
+        self.assertEqual(text, '{"diagnosis":"ok"}')
+
     def test_auth_headers_load_bailian_key_from_dotenv(self) -> None:
         with tempfile.TemporaryDirectory() as tmp:
             tmp_path = Path(tmp)