OpenTelemetry AWS Lambda Layer Not Propagating Parent Span ID in TypeScript Lambdas

[nirvana620]

Describe the Bug
OpenTelemetry auto-instrumentation for AWS Lambda is not correctly propagating parent span IDs when using the AWS Lambda Layer (otel-nodejs) in a TypeScript-based Lambda.

• JavaScript Lambdas work correctly.
• TypeScript Lambdas drop parent spans, causing traces to appear disconnected in the tracing backend.

What did you expect to see?

• The parent span ID should be propagated correctly.
• Traces should be connected to the parent spans.

What did you see instead?

• No parent span ID is retained.
• The trace appears disconnected in the tracing backend.

This is a single lambda invocation with no parent ID and every span is seperated.

Timestamp (Local)	Level	Service	span_id	trace_id	Message
Mar 12 4:37:55.769 PM	ok	hasEligibleMacAddressHandler	36b4fac9cbc266b5	67531b345b422befaa60232c084627f2	dns.lookup
Mar 12 4:37:55.750 PM	ok	hasEligibleMacAddressHandler	3885f329e9bebb07	2c3d9bfa77566d65f5c38f5da7d93a4a	200 GET http://localhost:2773/secretsmanager/get?secretId=qa/account-vehicle-service
Mar 12 4:37:54.410 PM	ok	hasEligibleMacAddressHandler	52b262ff58a7ea20	cf72478ab8a4685ee978993d68836472	tcp.connect
Mar 12 4:37:54.410 PM	ok	hasEligibleMacAddressHandler	65e34bc896c4cf37	a07d26a6688312bcfeba166c529a1789	dns.lookup
Mar 12 4:37:54.170 PM	ok	hasEligibleMacAddressHandler	31c1c10fdb703664	b1c852b61f035eebdfd3a0e270344b61	tcp.connect
Mar 12 4:37:54.170 PM	ok	hasEligibleMacAddressHandler	dff7c0e0a8f2980e	e7a3992157fa443137799f0e1a6e3cf5	dns.lookup

What version of collector/language SDK version did you use?

• Lambda Layer (OTel Node.js):
  • arn:aws:lambda:us-east-2:184161586896:layer:opentelemetry-nodejs-0_12_0:1
• Lambda Layer (OTel Collector):
  • arn:aws:lambda:us-east-2:184161586896:layer:opentelemetry-collector-amd64-0_13_0:1

What language layer did you use?
nodejs

Additional context
If I manually propagate a parent trace through the lambda we'll be able to preserve the parent ID and trace continuity, I expect the lambda layer to autoinstrument the parent ID.

` // Extract traceparent from headers
const headers = event.headers || {};
const traceparentHeader = headers['traceparent'];

// Propagate traceparent if available
let ctx = context.active();
if (traceparentHeader) {
ctx = propagation.extract(ctx, { traceparent: traceparentHeader });
}
`
This forces a parent span and connects the traces, but shouldn't be necessary if the OpenTelemetry AWS Lambda layer is functioning correctly.

We've ruled out

• lambda layer configuration
• node versioning
• layer version
• secretsmanager lambda layer
• custom logging packages
• potential async issues

Questions for Maintainers

• Is this a known issue with OpenTelemetry auto-instrumentation in TypeScript-based AWS Lambdas?
• Is there a recommended workaround to ensure traces remain linked without requiring manual propagation?
• Could ESBuild bundling or Lambda execution order interfere with OpenTelemetry’s automatic instrumentation?

[serkan-ozal]

Hi @nirvana620,

As far as I see from your example (listed spans), there is no AWS Lambda invocation span for the TypeScript Lambda. So it thinks me that your Lambda handler is not auto instrumented (wrapped) and it might be caused by ESBuild.

So, can you be sure that when you build your TypeScript Lambda with ESBuild, the handler name you set to Lambda configuration points to the valid point in the built/generated JS file by the ESBuild?