[BUG]: Bedrock agent tracing bug when there's a Knowledge base trace involved #17153
Description
Tracer Version(s)
4.6.4
Python Version(s)
3.11
Pip Version(s)
26.0.1
Bug Report
When a bedrock trace includes a knowledge base observation type, there is an error. Replace this line in bedrock_agents.py with the code below seems to fix it:
output_value = output_chunk.get("retrievedReferences", {}).get("text", "")
retrieved = output_chunk.get("retrievedReferences", [])
if isinstance(retrieved, list):
output_value = retrieved[0].get("content", {}).get("text", "") if retrieved else ""
else:
output_value = retrieved.get("text", "")
Reproduction Code
def invoke_bedrock_agent(conversation_id: str, user_text: str) -> str:
agent_id = os.environ["BEDROCK_AGENT_ID"]
agent_alias_id = os.environ["BEDROCK_AGENT_ALIAS_ID"]
with tracer.start_as_current_span("bedrock.invoke_agent") as span:
span.set_attribute("llm.provider", "aws_bedrock")
span.set_attribute("bedrock.agent_id", agent_id)
span.set_attribute("bedrock.agent_alias_id", agent_alias_id)
span.set_attribute("bedrock.session_id", conversation_id)
span.set_attribute("input.text", user_text[:1000])
response = bedrock.invoke_agent(
agentId=agent_id,
agentAliasId=agent_alias_id,
sessionId=conversation_id,
inputText=user_text,
enableTrace=True,
)
chunks = []
raw_trace_events = []
for event in response["completion"]:
chunk = event.get("chunk")
if chunk and chunk.get("bytes"):
chunks.append(chunk["bytes"].decode("utf-8"))
output_text = "".join(chunks)
return output_text
Error Logs
Error translating Bedrock traces
Traceback (most recent call last):
File "/Users/user/Projects/cap-ai-utils/.venv/lib/python3.11/site-packages/ddtrace/contrib/internal/botocore/services/bedrock_agents.py", line 39, in iter
self._dd_integration.translate_bedrock_traces(traces, self._dd_span)
File "/Users/user/Projects/cap-ai-utils/.venv/lib/python3.11/site-packages/ddtrace/llmobs/_integrations/bedrock.py", line 176, in translate_bedrock_traces
translated_span_event, finished = translate_bedrock_trace(
^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/user/Projects/cap-ai-utils/.venv/lib/python3.11/site-packages/ddtrace/llmobs/_integrations/bedrock_agents.py", line 522, in translate_bedrock_trace
translated_span_event, finished = translation_method(trace, root_span, current_active_span_event, trace_step_id)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/user/Projects/cap-ai-utils/.venv/lib/python3.11/site-packages/ddtrace/llmobs/_integrations/bedrock_agents.py", line 225, in _translate_orchestration_trace
return _observation_span(observation, root_span, current_active_span), True
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/user/Projects/cap-ai-utils/.venv/lib/python3.11/site-packages/ddtrace/llmobs/_integrations/bedrock_agents.py", line 479, in _observation_span
output_value = output_chunk.get("retrievedReferences", {}).get("text", "")
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'list' object has no attribute 'get'
ERROR:ddtrace.contrib.internal.botocore.services.bedrock_agents:Error translating Bedrock traces
Traceback (most recent call last):
File "/Users/user/Projects/cap-ai-utils/.venv/lib/python3.11/site-packages/ddtrace/contrib/internal/botocore/services/bedrock_agents.py", line 39, in iter
self._dd_integration.translate_bedrock_traces(traces, self._dd_span)
File "/Users/user/Projects/cap-ai-utils/.venv/lib/python3.11/site-packages/ddtrace/llmobs/_integrations/bedrock.py", line 176, in translate_bedrock_traces
translated_span_event, finished = translate_bedrock_trace(
^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/user/Projects/cap-ai-utils/.venv/lib/python3.11/site-packages/ddtrace/llmobs/_integrations/bedrock_agents.py", line 522, in translate_bedrock_trace
translated_span_event, finished = translation_method(trace, root_span, current_active_span_event, trace_step_id)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/user/Projects/cap-ai-utils/.venv/lib/python3.11/site-packages/ddtrace/llmobs/_integrations/bedrock_agents.py", line 225, in _translate_orchestration_trace
return _observation_span(observation, root_span, current_active_span), True
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/user/Projects/cap-ai-utils/.venv/lib/python3.11/site-packages/ddtrace/llmobs/_integrations/bedrock_agents.py", line 479, in _observation_span
output_value = output_chunk.get("retrievedReferences", {}).get("text", "")
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'list' object has no attribute 'get'
Libraries in Use
annotated-doc==0.0.4
annotated-types==0.7.0
anyio==4.13.0
attrs==26.1.0
autopep8==2.3.2
bedrock-agentcore==1.3.0
bedrock-agentcore-starter-toolkit==0.2.10
boto3==1.42.76
botocore==1.42.76
braintrust==0.10.0
bytecode==0.17.0
certifi==2026.2.25
cffi==2.0.0
chardet==5.2.0
charset-normalizer==3.4.6
chevron==0.14.0
click==8.3.1
cryptography==46.0.5
ddtrace==4.6.4
docstring-parser==0.17.0
envier==0.6.1
exceptiongroup==1.3.1
fastapi==0.135.2
gitdb==4.0.12
gitpython==3.1.46
googleapis-common-protos==1.73.0
h11==0.16.0
httpcore==1.0.9
httpx==0.28.1
httpx-sse==0.4.3
idna==3.11
importlib-metadata==8.7.1
jinja2==3.1.6
jmespath==1.1.0
jsonschema==4.26.0
jsonschema-path==0.3.4
jsonschema-specifications==2025.9.1
lazy-object-proxy==1.12.0
markdown-it-py==4.0.0
markupsafe==3.0.3
mcp==1.26.0
mdurl==0.1.2
openapi-schema-validator==0.6.3
openapi-spec-validator==0.7.2
opentelemetry-api==1.40.0
opentelemetry-exporter-otlp-proto-common==1.40.0
opentelemetry-exporter-otlp-proto-http==1.40.0
opentelemetry-proto==1.40.0
opentelemetry-sdk==1.40.0
opentelemetry-semantic-conventions==0.61b0
packaging==26.0
pathable==0.4.4
prance==25.4.8.0
prompt-toolkit==3.0.52
protobuf==6.33.6
py-openapi-schema-to-json-schema==0.0.3
pycodestyle==2.14.0
pycparser==3.0
pydantic==2.12.5
pydantic-core==2.41.5
pydantic-settings==2.12.0
pygments==2.19.2
pyjwt==2.11.0
python-dateutil==2.9.0.post0
python-dotenv==1.2.2
python-multipart==0.0.22
python-slugify==8.0.4
pyyaml==6.0.3
questionary==2.1.1
referencing==0.37.0
requests==2.33.0
rfc3339-validator==0.1.4
rich==14.3.2
rpds-py==0.30.0
ruamel-yaml==0.19.1
s3transfer==0.16.0
shellingham==1.5.4
six==1.17.0
smmap==5.0.3
sse-starlette==3.2.0
sseclient-py==1.9.0
starlette==1.0.0
text-unidecode==1.3
toml==0.10.2
tqdm==4.67.3
typer==0.23.1
typing-extensions==4.15.0
typing-inspection==0.4.2
urllib3==2.6.3
uvicorn==0.42.0
wcwidth==0.6.0
websockets==16.0
wrapt==2.1.2
zipp==3.23.0
Operating System
Darwin Kernel Version 24.1.0