fix(copilot): mark native image requests as vision

Co-authored-by: dhabibi <9087935+dhabibi@users.noreply.github.com>

run_agent.py

@@ -5258,7 +5258,39 @@ class AIAgent:
             logger.debug("Dead connection check error: %s", exc)
         return False
 
-    def _create_request_openai_client(self, *, reason: str) -> Any:
+    @staticmethod
+    def _api_kwargs_have_image_parts(api_kwargs: dict) -> bool:
+        """Return True when the outbound request still contains native image parts."""
+        if not isinstance(api_kwargs, dict):
+            return False
+        candidates = []
+        messages = api_kwargs.get("messages")
+        if isinstance(messages, list):
+            candidates.extend(messages)
+        # Responses API payloads use `input`; after conversion, image parts can
+        # still be present there instead of in `messages`.
+        response_input = api_kwargs.get("input")
+        if isinstance(response_input, list):
+            candidates.extend(response_input)
+
+        def _contains_image(value: Any) -> bool:
+            if isinstance(value, dict):
+                ptype = value.get("type")
+                if ptype in {"image_url", "input_image"}:
+                    return True
+                return any(_contains_image(v) for v in value.values())
+            if isinstance(value, list):
+                return any(_contains_image(v) for v in value)
+            return False
+
+        return any(_contains_image(item) for item in candidates)
+
+    def _copilot_headers_for_request(self, *, is_vision: bool) -> dict:
+        from hermes_cli.copilot_auth import copilot_request_headers
+
+        return copilot_request_headers(is_agent_turn=True, is_vision=is_vision)
+
+    def _create_request_openai_client(self, *, reason: str, api_kwargs: Optional[dict] = None) -> Any:
         from unittest.mock import Mock
 
         primary_client = self._ensure_primary_openai_client(reason=reason)
@@ -5266,6 +5298,11 @@ class AIAgent:
             return primary_client
         with self._openai_client_lock():
             request_kwargs = dict(self._client_kwargs)
+        if (
+            base_url_host_matches(str(request_kwargs.get("base_url", "")), "api.githubcopilot.com")
+            and self._api_kwargs_have_image_parts(api_kwargs or {})
+        ):
+            request_kwargs["default_headers"] = self._copilot_headers_for_request(is_vision=True)
         return self._create_openai_client(request_kwargs, reason=reason, shared=False)
 
     def _close_request_openai_client(self, client: Any, *, reason: str) -> None:
@@ -5808,7 +5845,10 @@ class AIAgent:
         def _call():
             try:
                 if self.api_mode == "codex_responses":
-                    request_client_holder["client"] = self._create_request_openai_client(reason="codex_stream_request")
+                    request_client_holder["client"] = self._create_request_openai_client(
+                        reason="codex_stream_request",
+                        api_kwargs=api_kwargs,
+                    )
                     result["response"] = self._run_codex_stream(
                         api_kwargs,
                         client=request_client_holder["client"],
@@ -5840,7 +5880,10 @@ class AIAgent:
                         raise
                     result["response"] = normalize_converse_response(raw_response)
                 else:
-                    request_client_holder["client"] = self._create_request_openai_client(reason="chat_completion_request")
+                    request_client_holder["client"] = self._create_request_openai_client(
+                        reason="chat_completion_request",
+                        api_kwargs=api_kwargs,
+                    )
                     result["response"] = request_client_holder["client"].chat.completions.create(**api_kwargs)
             except Exception as e:
                 result["error"] = e
@@ -6183,7 +6226,8 @@ class AIAgent:
                 ),
             }
             request_client_holder["client"] = self._create_request_openai_client(
-                reason="chat_completion_stream_request"
+                reason="chat_completion_stream_request",
+                api_kwargs=stream_kwargs,
             )
             # Reset stale-stream timer so the detector measures from this
             # attempt's start, not a previous attempt's last chunk.

tests/run_agent/test_copilot_native_vision_headers.py

@@ -0,0 +1,96 @@
+from unittest.mock import MagicMock, patch
+
+from run_agent import AIAgent
+
+
+def _make_copilot_agent():
+    with patch("run_agent.OpenAI") as mock_openai:
+        mock_openai.return_value = MagicMock()
+        agent = AIAgent(
+            api_key="gh-token",
+            base_url="https://api.githubcopilot.com",
+            provider="copilot",
+            model="gpt-5.4",
+            quiet_mode=True,
+            skip_context_files=True,
+            skip_memory=True,
+        )
+    return agent
+
+
+def test_request_client_adds_copilot_vision_header_for_native_image_payload():
+    agent = _make_copilot_agent()
+    built_kwargs = []
+
+    def fake_create(kwargs, *, reason, shared):
+        built_kwargs.append(dict(kwargs))
+        return MagicMock()
+
+    api_kwargs = {
+        "model": "gpt-5.4",
+        "messages": [
+            {
+                "role": "user",
+                "content": [
+                    {"type": "text", "text": "What is in this image?"},
+                    {"type": "image_url", "image_url": {"url": "data:image/png;base64,abc"}},
+                ],
+            }
+        ],
+    }
+
+    agent.client = object()
+    with patch.object(agent, "_is_openai_client_closed", return_value=False), patch.object(
+        agent, "_create_openai_client", side_effect=fake_create
+    ):
+        agent._create_request_openai_client(reason="test", api_kwargs=api_kwargs)
+
+    headers = built_kwargs[-1]["default_headers"]
+    assert headers["Copilot-Vision-Request"] == "true"
+
+
+def test_request_client_leaves_copilot_text_requests_without_vision_header():
+    agent = _make_copilot_agent()
+    built_kwargs = []
+
+    def fake_create(kwargs, *, reason, shared):
+        built_kwargs.append(dict(kwargs))
+        return MagicMock()
+
+    api_kwargs = {"model": "gpt-5.4", "messages": [{"role": "user", "content": "hello"}]}
+
+    agent.client = object()
+    with patch.object(agent, "_is_openai_client_closed", return_value=False), patch.object(
+        agent, "_create_openai_client", side_effect=fake_create
+    ):
+        agent._create_request_openai_client(reason="test", api_kwargs=api_kwargs)
+
+    headers = built_kwargs[-1]["default_headers"]
+    assert "Copilot-Vision-Request" not in headers
+
+
+def test_request_client_does_not_add_vision_header_after_non_vision_fallback():
+    agent = _make_copilot_agent()
+    built_kwargs = []
+
+    def fake_create(kwargs, *, reason, shared):
+        built_kwargs.append(dict(kwargs))
+        return MagicMock()
+
+    # This is the shape after _prepare_messages_for_non_vision_model has
+    # replaced image parts with text, so Copilot should not get the vision route.
+    api_kwargs = {
+        "model": "gpt-5.4",
+        "messages": [
+            {"role": "user", "content": "[user image: a dog]\n\nWhat is in this image?"}
+        ],
+    }
+
+    agent.client = object()
+    with patch.object(agent, "_is_openai_client_closed", return_value=False), patch.object(
+        agent, "_create_openai_client", side_effect=fake_create
+    ):
+        agent._create_request_openai_client(reason="test", api_kwargs=api_kwargs)
+
+    headers = built_kwargs[-1]["default_headers"]
+    assert "Copilot-Vision-Request" not in headers