Propagate request model to agent spans

Author: nagkumar91

instrumentation-genai/opentelemetry-instrumentation-openai-agents-v2/src/opentelemetry/instrumentation/openai_agents/span_processor.py

@@ -1099,12 +1099,6 @@ def _update_agent_aggregate(
         self, span: Span[Any], payload: ContentPayload
     ) -> None:
         """Accumulate child span content for parent agent span."""
-        if not (
-            payload.input_messages
-            or payload.output_messages
-            or payload.system_instructions
-        ):
-            return
         agent_id = self._find_agent_parent_span_id(span.parent_id)
         if not agent_id:
             return
@@ -1114,6 +1108,7 @@ def _update_agent_aggregate(
                 "input_messages": [],
                 "output_messages": [],
                 "system_instructions": [],
+                "request_model": None,
             },
         )
         if payload.input_messages:
@@ -1129,6 +1124,14 @@ def _update_agent_aggregate(
                 entry["system_instructions"], payload.system_instructions
             )
 
+        if not entry.get("request_model"):
+            model = getattr(span.span_data, "model", None)
+            if not model:
+                response_obj = getattr(span.span_data, "response", None)
+                model = getattr(response_obj, "model", None)
+            if model:
+                entry["request_model"] = model
+
     def _infer_output_type(self, span_data: Any) -> str:
         """Infer gen_ai.output.type for multiple span kinds."""
         if _is_instance_of(span_data, FunctionSpanData):
@@ -1311,6 +1314,7 @@ def on_span_start(self, span: Span[Any]) -> None:
                 "input_messages": [],
                 "output_messages": [],
                 "system_instructions": [],
+                "request_model": None,
             }
 
         parent_span = (
@@ -1801,6 +1805,8 @@ def _get_attributes_from_agent_span_data(
             yield GEN_AI_AGENT_DESCRIPTION, description
 
         model = getattr(span_data, "model", None)
+        if not model and agent_content:
+            model = agent_content.get("request_model")
         if model:
             yield GEN_AI_REQUEST_MODEL, model
 

instrumentation-genai/opentelemetry-instrumentation-openai-agents-v2/tests/test_z_span_processor_unit.py

@@ -326,6 +326,27 @@ def __init__(self) -> None:
     assert agent_attrs[sp.GEN_AI_REQUEST_MODEL] == "model-x"
     assert agent_attrs[sp.GEN_AI_OUTPUT_TYPE] == sp.GenAIOutputType.TEXT
 
+    # Fallback to aggregated model when span data lacks it
+    agent_span_no_model = AgentSpanData(
+        name="helper-2",
+        output_type="json",
+        description="desc",
+        agent_id="agent-456",
+        operation="invoke_agent",
+    )
+    agent_content = {
+        "input_messages": [],
+        "output_messages": [],
+        "system_instructions": [],
+        "request_model": "gpt-fallback",
+    }
+    agent_attrs_fallback = _collect(
+        processor._get_attributes_from_agent_span_data(
+            agent_span_no_model, agent_content
+        )
+    )
+    assert agent_attrs_fallback[sp.GEN_AI_REQUEST_MODEL] == "gpt-fallback"
+
     function_span = FunctionSpanData(name="lookup_weather")
     function_span.tool_type = "extension"
     function_span.call_id = "call-42"