diff --git a/agent/transports/codex.py b/agent/transports/codex.py
index ea78c97b9f6..c362173696a 100644
--- a/agent/transports/codex.py
+++ b/agent/transports/codex.py
@@ -67,9 +67,9 @@ class ResponsesApiTransport(ProviderTransport):
         """Classify the current Responses endpoint from transport params."""
         from agent.codex_responses_adapter import _classify_responses_issuer
         return _classify_responses_issuer(
-            is_xai_responses=bool(params.get("is_xai_responses")),
-            is_github_responses=bool(params.get("is_github_responses")),
-            is_codex_backend=bool(params.get("is_codex_backend")),
+            is_xai_responses=params.get("is_xai_responses") is True,
+            is_github_responses=params.get("is_github_responses") is True,
+            is_codex_backend=params.get("is_codex_backend") is True,
             base_url=params.get("base_url"),
         )
 
@@ -80,8 +80,8 @@ class ResponsesApiTransport(ProviderTransport):
         self._last_issuer_kind = issuer
         return _chat_messages_to_responses_input(
             messages,
-            is_xai_responses=bool(kwargs.get("is_xai_responses")),
-            is_github_responses=bool(kwargs.get("is_github_responses")),
+            is_xai_responses=kwargs.get("is_xai_responses") is True,
+            is_github_responses=kwargs.get("is_github_responses") is True,
             replay_encrypted_reasoning=bool(
                 kwargs.get("replay_encrypted_reasoning", True)
             ),
@@ -138,9 +138,9 @@ class ResponsesApiTransport(ProviderTransport):
         if not instructions:
             instructions = DEFAULT_AGENT_IDENTITY
 
-        is_github_responses = params.get("is_github_responses", False)
-        is_codex_backend = params.get("is_codex_backend", False)
-        is_xai_responses = params.get("is_xai_responses", False)
+        is_github_responses = params.get("is_github_responses") is True
+        is_codex_backend = params.get("is_codex_backend") is True
+        is_xai_responses = params.get("is_xai_responses") is True
         replay_encrypted_reasoning = bool(
             params.get("replay_encrypted_reasoning", True)
         )
diff --git a/tests/agent/test_auxiliary_client.py b/tests/agent/test_auxiliary_client.py
index d4bab973a9e..95bc4e6f1b5 100644
--- a/tests/agent/test_auxiliary_client.py
+++ b/tests/agent/test_auxiliary_client.py
@@ -4109,7 +4109,7 @@ class TestCodexAdapterGithubResponsesMessageIdDrop:
                     {
                         "type": "message",
                         "role": "assistant",
-                        "status": "completed",
+                        "status": "in_progress",
                         "content": [{"type": "output_text", "text": "pong"}],
                         "id": "msg_short_but_connection_scoped",
                         "phase": "final_answer",
@@ -4127,6 +4127,8 @@ class TestCodexAdapterGithubResponsesMessageIdDrop:
         )
         assert "id" not in message_item
         assert message_item["phase"] == "final_answer"
+        assert message_item["status"] == "in_progress"
+        assert message_item["content"] == [{"type": "output_text", "text": "pong"}]
 
     def test_keeps_message_id_for_codex_backend_host(self):
         adapter, captured = self._build_adapter(
diff --git a/tests/agent/transports/test_codex_transport.py b/tests/agent/transports/test_codex_transport.py
index 6116d3978fb..84a269feef8 100644
--- a/tests/agent/transports/test_codex_transport.py
+++ b/tests/agent/transports/test_codex_transport.py
@@ -138,7 +138,7 @@ class TestCodexBuildKwargs:
                     {
                         "type": "message",
                         "role": "assistant",
-                        "status": "completed",
+                        "status": "in_progress",
                         "content": [{"type": "output_text", "text": "pong"}],
                         "id": "msg_short_but_connection_scoped",
                         "phase": "final_answer",
@@ -153,6 +153,33 @@ class TestCodexBuildKwargs:
         message_item = next(item for item in kw["input"] if item.get("type") == "message")
         assert "id" not in message_item
         assert message_item["phase"] == "final_answer"
+        assert message_item["status"] == "in_progress"
+        assert message_item["content"] == [{"type": "output_text", "text": "pong"}]
+
+    def test_github_responses_requires_literal_true(self, transport):
+        messages = [
+            {
+                "role": "assistant",
+                "content": "pong",
+                "codex_message_items": [
+                    {
+                        "type": "message",
+                        "role": "assistant",
+                        "status": "completed",
+                        "content": [{"type": "output_text", "text": "pong"}],
+                        "id": "msg_short_id",
+                    }
+                ],
+            },
+        ]
+
+        kw = transport.build_kwargs(
+            model="gpt-5.5", messages=messages, tools=[],
+            is_github_responses="false",
+        )
+
+        message_item = next(item for item in kw["input"] if item.get("type") == "message")
+        assert message_item["id"] == "msg_short_id"
 
     def test_non_github_responses_keeps_message_item_id_end_to_end(self, transport):
         messages = [