Ensure AWS SDK instrumentation works >= 3.1046.0

[mydea]

Summary

The vendored @opentelemetry/instrumentation-aws-sdk (AwsInstrumentation, used by awsIntegration in @sentry/aws-serverless) silently produces no spans for applications using @aws-sdk/* client packages at version 3.1046.0 or newer (published 2026-05-14 onwards). All AWS service spans (S3, DynamoDB, SQS, SNS, Lambda, Kinesis, etc.) are missing — there is no error, the instrumentation simply never attaches.

Root cause

AwsInstrumentation creates spans by patching the AWS SDK v3 middleware plumbing. Its init() registers patches for:

• @aws-sdk/middleware-stack and @smithy/middleware-stack → wraps constructStack, which wraps the stack's resolve to start the span (this is the span-creation entry point)
• @aws-sdk/smithy-client and @smithy/smithy-client → wraps Client.prototype.send to attach the client config (used for the region attribute)

Starting with @aws-sdk/client-*@3.1046.0, AWS SDK JS v3 migrated to schema-based serialization and consolidated the middleware stack and smithy client into @smithy/core. The clients no longer depend on (or require) @smithy/middleware-stack or @smithy/smithy-client.

Because the modules the instrumentation hooks are no longer in the require graph, the require-in-the-middle hooks never fire, constructStack is never wrapped, and no spans are created.

When it was introduced

Bisecting @aws-sdk/client-s3 dependency metadata:

Version	@smithy/middleware-stack	@smithy/smithy-client	@smithy/core	Instrumented?
3.1045.0 (2026-05-07)	^4.2.14	^4.12.13	^3.23.17	✅ yes
3.1046.0 (2026-05-14)	— (removed)	— (removed)	^3.24.1	❌ no

So the regression is in the SDK side and affects @aws-sdk/* >= 3.1046.0, correlating with @smithy/core >= 3.24.x.

Reproduction

const Sentry = require('@sentry/aws-serverless');
Sentry.init({ dsn: '...', tracesSampleRate: 1.0 });

const { DynamoDBClient, PutItemCommand } = require('@aws-sdk/client-dynamodb'); // >= 3.1046.0
const client = new DynamoDBClient({ region: 'us-east-1' });

await Sentry.startSpan({ name: 'tx' }, async () => {
 await client.send(new PutItemCommand({ TableName: 't', Item: { id: { S: 'x' } } }));
});
// => the transaction contains NO `DynamoDB.PutItem` span

With @aws-sdk/*@3.1045.0 (or 3.1041.0) the same code produces the expected span. Verified locally while writing the integration tests in #21543 — pinning the test clients to 3.1041.0 produces spans; 3.1068.0 produces none. Only @smithy/core, @smithy/types, @smithy/signature-v4, and @smithy/node-http-handler are loaded for the newer clients (none of which the instrumentation patches).

Suggested fix

Add patching for the new @smithy/core schema-client mechanism — i.e. wrap constructStack / the middleware-resolve path wherever it now lives inside @smithy/core (and confirm how the client config is now exposed for the region attribute). This needs investigation into the new @smithy/core API surface.

Worth also checking whether upstream @opentelemetry/instrumentation-aws-sdk has already addressed this, so we can mirror their approach when we streamline the vendored instrumentation.

Notes

• This is why the integration tests added in test(aws-serverless): Add integration coverage for aws-sdk service instrumentation #21543 pin @aws-sdk/client-* to 3.1041.0 — the newer clients are not instrumented, so tests against them would assert against empty span lists.
• Related: Streamline @opentelemetry/instrumentation-aws-sdk #20944 (streamlining the vendored aws-sdk instrumentation).

[linear-code]

JS-2775

[github-actions]

A PR closing this issue has just been released 🚀

This issue was referenced by PR #21548, which was included in the 10.59.0 release.