[BUG] OpenTelemetry traces not using parent span context

[Jasonlin1198]

Checks

• I have updated to the lastest minor and patch version of Strands
• I have checked the documentation and this is not expected behavior
• I have searched ./issues and there are no duplicates of my issue

Strands Version

0.1.8

Python Version

3.10

Operating System

macOS 15.5

Installation Method

other

Steps to Reproduce

Setup:

• Python Lambda deployed with Dockerfile on ARM64
• ADOT Python Lambda Layer: arn:aws:lambda:us-west-2:901920570463:layer:aws-otel-python-arm64-ver-1-32-0:2
• CDK Lambda property set to tracing: Tracing.ACTIVE

extensions:
  sigv4auth:
    service: xray
    region: ${env:AWS_REGION}

receivers:
  otlp:
    protocols:
      # Strands Agents SDK uses Http OTLP exporter
      # https://github.com/strands-agents/sdk-python/blob/d8ce2d5e69322211b281567eb0da99e0ba47b574/src/strands/telemetry/tracer.py#L38
      http:
        endpoint: 'localhost:4318'

exporters:
  otlphttp:
    compression: gzip
    traces_endpoint: https://xray.${env:AWS_REGION}.amazonaws.com/v1/traces
    auth:
      authenticator: sigv4auth

service:
  extensions: [sigv4auth]
  pipelines:
    traces:
      receivers: [otlp]
      exporters: [otlphttp]

# Instantiate Tracer
tracer = get_tracer(service_name="JvlinStrandsAgents", otlp_endpoint="http://localhost:4318/")

AWS X-Ray trace service map:

Expected Behavior

Expecting Lambda Context, Lambda Function to be the only nodes as Strands Agents SDK runs internally within the Lambda Function itself.

The Strands Agents SDK created spans should be within the Invocation span parent.

Actual Behavior

Current tracer implementation:

def _start_span(
    self,
    span_name: str,
    parent_span: Optional[Span] = None,
    attributes: Optional[Dict[str, AttributeValue]] = None,
) -> Optional[Span]:
    """Generic helper method to start a span with common attributes.

    Args:
        span_name: Name of the span to create
        parent_span: Optional parent span to link this span to
        attributes: Dictionary of attributes to set on the span

    Returns:
        The created span, or None if tracing is not enabled
    """
    if self.tracer is None:
        return None

    context = trace_api.set_span_in_context(parent_span) if parent_span else None
    span = self.tracer.start_span(name=span_name, context=context)

    # Set start time as a common attribute
    span.set_attribute("gen_ai.event.start_time", datetime.now(timezone.utc).isoformat())

    # Add all provided attributes
    if attributes:
        self._set_attributes(span, attributes)

    return span

To be modified so that existing span context coming from outside of the Strands Agents SDK is used.

Additional Context

No response

Possible Solution

No response

Related Issues

No response