fix(openai-agents): serialize complex output types to JSON for AttributeValue compatibility

Handle edge cases where FunctionCallOutput and ResponseCustomToolCallOutputParam contain complex output types (lists, dicts) that don't match AttributeValue type. Serialize these to JSON strings while preserving None and string values.

Author: codefromthecrypt

python/instrumentation/openinference-instrumentation-openai-agents/pyproject.toml

@@ -84,6 +84,12 @@ module = [
   "agents.*",
 ]
 
+# openai library types differ between v1.99.9 (py39) and v2.7.2 (py313-latest),
+# causing type ignores to be unused in one version but required in the other.
+[[tool.mypy.overrides]]
+module = "tests.test_span_attribute_helpers"
+warn_unused_ignores = false
+
 [tool.ruff]
 line-length = 100
 target-version = "py38"

python/instrumentation/openinference-instrumentation-openai-agents/src/openinference/instrumentation/openai_agents/_processor.py

@@ -361,8 +361,14 @@ def _get_attributes_from_response_custom_tool_call_output_param(
     yield f"{prefix}{MessageAttributes.MESSAGE_ROLE}", "tool"
     if (call_id := obj.get("call_id")) is not None:
         yield f"{prefix}{MessageAttributes.MESSAGE_TOOL_CALL_ID}", call_id
-    if (output := obj.get("output")) is not None:
-        yield f"{prefix}{MessageAttributes.MESSAGE_CONTENT}", output
+    if "output" in obj:
+        output = obj["output"]
+        if output is not None:
+            if isinstance(output, str):
+                output_value = output
+            else:
+                output_value = safe_json_dumps(output)
+            yield f"{prefix}{MessageAttributes.MESSAGE_CONTENT}", output_value
 
 
 def _get_attributes_from_function_call_output(
@@ -371,7 +377,13 @@ def _get_attributes_from_function_call_output(
 ) -> Iterator[tuple[str, AttributeValue]]:
     yield f"{prefix}{MESSAGE_ROLE}", "tool"
     yield f"{prefix}{MESSAGE_TOOL_CALL_ID}", obj["call_id"]
-    yield f"{prefix}{MESSAGE_CONTENT}", obj["output"]
+    output = obj["output"]
+    if output is not None:
+        if isinstance(output, str):
+            output_value = output
+        else:
+            output_value = safe_json_dumps(output)
+        yield f"{prefix}{MESSAGE_CONTENT}", output_value
 
 
 def _get_attributes_from_generation_span_data(

python/instrumentation/openinference-instrumentation-openai-agents/tests/test_span_attribute_helpers.py

@@ -38,6 +38,9 @@
     ResponseUsage,
     Tool,
 )
+from openai.types.responses.response_custom_tool_call_output_param import (
+    ResponseCustomToolCallOutputParam,
+)
 from openai.types.responses.response_function_web_search_param import ActionSearch
 from openai.types.responses.response_input_item_param import (
     ComputerCallOutput,
@@ -265,6 +268,51 @@
             },
             id="item_reference",
         ),
+        pytest.param(
+            [
+                ResponseCustomToolCallOutputParam(
+                    type="custom_tool_call_output",
+                    call_id="custom-123",
+                    output="simple result",
+                )
+            ],
+            {
+                "llm.input_messages.1.message.content": "simple result",
+                "llm.input_messages.1.message.role": "tool",
+                "llm.input_messages.1.message.tool_call_id": "custom-123",
+            },
+            id="custom_tool_call_output_string",
+        ),
+        pytest.param(
+            [
+                ResponseCustomToolCallOutputParam(
+                    type="custom_tool_call_output",
+                    call_id="custom-123",
+                    output=["item1", "item2"],  # type: ignore[typeddict-item,list-item]
+                )
+            ],
+            {
+                "llm.input_messages.1.message.content": '["item1", "item2"]',
+                "llm.input_messages.1.message.role": "tool",
+                "llm.input_messages.1.message.tool_call_id": "custom-123",
+            },
+            id="custom_tool_call_output_list",
+        ),
+        pytest.param(
+            [
+                ResponseCustomToolCallOutputParam(
+                    type="custom_tool_call_output",
+                    call_id="custom-123",
+                    output={"status": "success", "data": 42},  # type: ignore
+                )
+            ],
+            {
+                "llm.input_messages.1.message.content": '{"status": "success", "data": 42}',
+                "llm.input_messages.1.message.role": "tool",
+                "llm.input_messages.1.message.tool_call_id": "custom-123",
+            },
+            id="custom_tool_call_output_dict",
+        ),
     ],
 )
 def test_get_attributes_from_input(
@@ -421,12 +469,35 @@ def test_get_attributes_from_response_function_tool_call_param(
                 "output": None,
             },
             {
-                "message.content": None,
                 "message.role": "tool",
                 "message.tool_call_id": "123",
             },
             id="none_output",
         ),
+        pytest.param(
+            {
+                "call_id": "123",
+                "output": [{"type": "text", "text": "result"}],
+            },
+            {
+                "message.content": '[{"type": "text", "text": "result"}]',
+                "message.role": "tool",
+                "message.tool_call_id": "123",
+            },
+            id="list_output",
+        ),
+        pytest.param(
+            {
+                "call_id": "123",
+                "output": {"result": "success", "value": 42},
+            },
+            {
+                "message.content": '{"result": "success", "value": 42}',
+                "message.role": "tool",
+                "message.tool_call_id": "123",
+            },
+            id="dict_output",
+        ),
     ],
 )
 def test_get_attributes_from_function_call_output(