fix(proxy/memory): harden _extract_tool_calls against malformed choices and blocks

headroom/proxy/memory_handler.py

@@ -1056,17 +1056,30 @@ def _extract_tool_calls(
         if provider == "anthropic":
             content = response.get("content", [])
             if isinstance(content, list):
-                return [block for block in content if block.get("type") == "tool_use"]
+                return [
+                    block
+                    for block in content
+                    if isinstance(block, dict) and block.get("type") == "tool_use"
+                ]
             return []
 
         elif provider == "openai":
-            # Chat Completions format: choices[0].message.tool_calls
-            choices = response.get("choices", [])
-            if choices:
-                message = choices[0].get("message", {})
-                tc_list = list(message.get("tool_calls", []) or [])
-                if tc_list:
-                    return tc_list
+            # Chat Completions format: choices[0].message.tool_calls. Guard the
+            # first choice for dict-ness the way the sibling
+            # CCRResponseHandler._extract_assistant_message already does: an
+            # OpenAI-compatible gateway can send `choices: [null]` on a
+            # content-filtered / usage-only response, and this runs from
+            # has_memory_tool_calls, which is called outside the try that wraps
+            # the rest of memory handling — so an unguarded `choices[0].get` here
+            # would surface AttributeError to the request handler.
+            choices = response.get("choices")
+            first = choices[0] if isinstance(choices, list) and choices else None
+            if isinstance(first, dict):
+                message = first.get("message")
+                if isinstance(message, dict):
+                    tc_list = list(message.get("tool_calls", []) or [])
+                    if tc_list:
+                        return tc_list
 
             # Responses API format: output[] with type=function_call
             output = response.get("output", [])

tests/test_memory_handler_null_function.py

@@ -34,3 +34,32 @@ def test_has_memory_tool_calls_survives_null_function():
 def test_has_memory_tool_calls_all_null_functions_is_false():
     response = _openai_response([{"id": "c1", "type": "function", "function": None}])
     assert _handler.has_memory_tool_calls(response, "openai") is False
+
+
+def test_extract_tool_calls_survives_null_choice_element():
+    # An OpenAI-compatible gateway can send `choices: [null]` on a
+    # content-filtered / usage-only response. `choices[0].get(...)` on the null
+    # element would raise AttributeError; detection must treat it as no tool
+    # calls, matching the sibling guard in CCRResponseHandler.
+    for choices in ([None], ["not-a-dict"], [{"message": None}]):
+        response = {"choices": choices}
+        assert _handler._extract_tool_calls(response, "openai") == []
+        assert _handler.has_memory_tool_calls(response, "openai") is False
+
+
+def test_extract_tool_calls_falls_through_to_responses_output():
+    # A null first choice must not shadow a Responses-API `output[]` payload in
+    # the same response; the function_call there is still detected.
+    response = {
+        "choices": [None],
+        "output": [{"type": "function_call", "name": "memory_save", "arguments": "{}"}],
+    }
+    assert _handler.has_memory_tool_calls(response, "openai") is True
+
+
+def test_extract_tool_calls_survives_non_dict_anthropic_block():
+    # A reconstructed Anthropic response may carry a null content block; the
+    # `block.get("type")` filter must skip it instead of raising.
+    response = {"content": [None, {"type": "tool_use", "id": "t1", "name": "memory_save"}]}
+    calls = _handler._extract_tool_calls(response, "anthropic")
+    assert [c["id"] for c in calls] == ["t1"]