From cc3418e069f39511d1f11702aa5de9c3fcb0f033 Mon Sep 17 00:00:00 2001
From: Alex Fournier <afournier@nvidia.com>
Date: Mon, 17 Aug 2026 10:17:52 -0700
Subject: [PATCH] fix(openai): complete sparse response normalization

Signed-off-by: Alex Fournier <afournier@nvidia.com>
---
 agent/transports/chat_completions.py          | 21 +++++--
 .../agent/transports/test_chat_completions.py | 59 +++++++++++++++++--
 2 files changed, 70 insertions(+), 10 deletions(-)

diff --git a/agent/transports/chat_completions.py b/agent/transports/chat_completions.py
index c62bcdf607..b628e22bac 100644
--- a/agent/transports/chat_completions.py
+++ b/agent/transports/chat_completions.py
@@ -756,9 +756,9 @@ class ChatCompletionsTransport(ProviderTransport):
         preserved for downstream replay.
         """
         choice = response.choices[0]
-        msg = choice.message
+        msg = getattr(choice, "message", None)
         # Poolside returns integer finish_reason (e.g. 24) instead of string
-        _fr = choice.finish_reason
+        _fr = getattr(choice, "finish_reason", None)
         if isinstance(_fr, int):
             _fr = str(_fr)
         finish_reason = _fr or "stop"
@@ -768,6 +768,13 @@ class ChatCompletionsTransport(ProviderTransport):
         if message_tool_calls:
             tool_calls = []
             for tc in message_tool_calls:
+                tc_function = getattr(tc, "function", None)
+                function_name = getattr(tc_function, "name", None)
+                # Match Relay's codec: skip absent function/name fields, but
+                # preserve an explicit blank name for Hermes's recovery path.
+                if tc_function is None or function_name is None:
+                    continue
+                function_arguments = getattr(tc_function, "arguments", None)
                 # Preserve provider-specific extras on the tool call.
                 # Gemini 3 thinking models attach extra_content with
                 # thought_signature — without replay on the next turn the API
@@ -790,9 +797,13 @@ class ChatCompletionsTransport(ProviderTransport):
                     tc_provider_data["extra_content"] = extra
                 tool_calls.append(
                     ToolCall(
-                        id=tc.id,
-                        name=tc.function.name,
-                        arguments=tc.function.arguments,
+                        id=getattr(tc, "id", None),
+                        name=function_name,
+                        arguments=(
+                            function_arguments
+                            if function_arguments is not None
+                            else "{}"
+                        ),
                         provider_data=tc_provider_data or None,
                     )
                 )
diff --git a/tests/agent/transports/test_chat_completions.py b/tests/agent/transports/test_chat_completions.py
index d8b9dcce5d..64910d93bb 100644
--- a/tests/agent/transports/test_chat_completions.py
+++ b/tests/agent/transports/test_chat_completions.py
@@ -18,12 +18,46 @@ def transport():
 
 
 class TestChatCompletionsBasic:
-    def test_normalize_response_allows_missing_optional_message_fields(self, transport):
+    @pytest.mark.parametrize(
+        "choice",
+        [SimpleNamespace(message=SimpleNamespace()), SimpleNamespace()],
+    )
+    def test_normalize_response_allows_missing_optional_message_fields(
+        self, transport, choice
+    ):
+        response = SimpleNamespace(choices=[choice], usage=None)
+
+        normalized = transport.normalize_response(response)
+
+        assert normalized.content is None
+        assert normalized.tool_calls is None
+        assert normalized.finish_reason == "stop"
+
+    def test_normalize_response_allows_sparse_tool_call_fields(self, transport):
         response = SimpleNamespace(
             choices=[
                 SimpleNamespace(
-                    message=SimpleNamespace(),
-                    finish_reason="stop",
+                    message=SimpleNamespace(
+                        tool_calls=[
+                            SimpleNamespace(
+                                function=SimpleNamespace(arguments='{"city":"Paris"}')
+                            ),
+                            SimpleNamespace(),
+                            SimpleNamespace(
+                                id="call-3",
+                                function=SimpleNamespace(name="lookup"),
+                            ),
+                            SimpleNamespace(
+                                id="call-4",
+                                function=SimpleNamespace(name="", arguments="{}"),
+                            ),
+                            SimpleNamespace(
+                                function=SimpleNamespace(
+                                    name="weather", arguments="{}"
+                                )
+                            ),
+                        ]
+                    )
                 )
             ],
             usage=None,
@@ -31,8 +65,23 @@ class TestChatCompletionsBasic:
 
         normalized = transport.normalize_response(response)
 
-        assert normalized.content is None
-        assert normalized.tool_calls is None
+        assert normalized.finish_reason == "stop"
+        assert normalized.tool_calls is not None
+        assert [tool.id for tool in normalized.tool_calls] == [
+            "call-3",
+            "call-4",
+            None,
+        ]
+        assert [tool.name for tool in normalized.tool_calls] == [
+            "lookup",
+            "",
+            "weather",
+        ]
+        assert [tool.arguments for tool in normalized.tool_calls] == [
+            "{}",
+            "{}",
+            "{}",
+        ]
 
     @pytest.mark.parametrize("provider", ["nous", "openrouter"])
     def test_gpt56_ultra_uses_max_wire_effort(self, transport, provider):