Record finish reasons on generation spans

Author: nagkumar91

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

@@ -1618,6 +1618,20 @@ def _get_attributes_from_generation_span_data(
         if hasattr(span_data, "data_source_id"):
             yield GEN_AI_DATA_SOURCE_ID, span_data.data_source_id
 
+        finish_reasons: list[Any] = []
+        if span_data.output:
+            for part in span_data.output:
+                if isinstance(part, dict):
+                    fr = part.get("finish_reason") or part.get("stop_reason")
+                else:
+                    fr = getattr(part, "finish_reason", None)
+                if fr:
+                    finish_reasons.append(
+                        fr if isinstance(fr, str) else str(fr)
+                    )
+        if finish_reasons:
+            yield GEN_AI_RESPONSE_FINISH_REASONS, finish_reasons
+
         # Usage information
         if span_data.usage:
             usage = span_data.usage

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

@@ -272,6 +272,7 @@ def test_attribute_builders(processor_setup):
     assert gen_attrs[ServerAttributes.SERVER_PORT] == 443
     assert gen_attrs[sp.GEN_AI_USAGE_INPUT_TOKENS] == 10
     assert gen_attrs[sp.GEN_AI_USAGE_OUTPUT_TOKENS] == 3
+    assert gen_attrs[sp.GEN_AI_RESPONSE_FINISH_REASONS] == ["stop"]
     assert json.loads(gen_attrs[sp.GEN_AI_INPUT_MESSAGES])[0]["role"] == "user"
     assert (
         json.loads(gen_attrs[sp.GEN_AI_OUTPUT_MESSAGES])[0]["role"]
@@ -306,6 +307,7 @@ def __init__(self) -> None:
     )
     assert response_attrs[sp.GEN_AI_RESPONSE_ID] == "resp-1"
     assert response_attrs[sp.GEN_AI_RESPONSE_MODEL] == "gpt-4o"
+    assert response_attrs[sp.GEN_AI_RESPONSE_FINISH_REASONS] == ["stop"]
     assert response_attrs[sp.GEN_AI_USAGE_INPUT_TOKENS] == 7
     assert response_attrs[sp.GEN_AI_USAGE_OUTPUT_TOKENS] == 2
     assert response_attrs[sp.GEN_AI_OUTPUT_TYPE] == sp.GenAIOutputType.TEXT