fix(agent): treat Codex reasoning items as thinking-only

run_agent.py

@@ -3297,6 +3297,16 @@ class AIAgent:
         rd = msg.get("reasoning_details")
         if isinstance(rd, list) and rd:
             return True
+        # Codex Responses stores encrypted reasoning state under a separate
+        # assistant-message key. Treat only real reasoning items as
+        # thinking-only; empty/junk lists should fall through to the generic
+        # empty-turn handling instead of being dropped here.
+        codex_items = msg.get("codex_reasoning_items")
+        if isinstance(codex_items, list):
+            return any(
+                isinstance(item, dict) and item.get("type") == "reasoning"
+                for item in codex_items
+            )
         return False
 
     @staticmethod

tests/run_agent/test_thinking_only_sanitizer.py

@@ -104,6 +104,38 @@ class TestIsThinkingOnlyAssistant:
         }
         assert AIAgent._is_thinking_only_assistant(msg)
 
+    def test_codex_reasoning_items_list_form_detected(self):
+        msg = {
+            "role": "assistant",
+            "content": "",
+            "codex_reasoning_items": [
+                {"type": "reasoning", "id": "rs_123", "encrypted_content": "enc_blob"}
+            ],
+        }
+        assert AIAgent._is_thinking_only_assistant(msg)
+
+    def test_codex_reasoning_items_with_visible_text_is_not_thinking_only(self):
+        msg = {
+            "role": "assistant",
+            "content": "Visible answer",
+            "codex_reasoning_items": [
+                {"type": "reasoning", "id": "rs_123", "encrypted_content": "enc_blob"}
+            ],
+        }
+        assert not AIAgent._is_thinking_only_assistant(msg)
+
+    def test_empty_codex_reasoning_items_list_is_not_thinking_only(self):
+        msg = {"role": "assistant", "content": "", "codex_reasoning_items": []}
+        assert not AIAgent._is_thinking_only_assistant(msg)
+
+    def test_non_reasoning_codex_items_are_not_thinking_only(self):
+        msg = {
+            "role": "assistant",
+            "content": "",
+            "codex_reasoning_items": [None, "x", {"type": "other"}],
+        }
+        assert not AIAgent._is_thinking_only_assistant(msg)
+
     def test_user_message_never_thinking_only(self):
         assert not AIAgent._is_thinking_only_assistant({"role": "user", "content": ""})