refactor: Added `@smithy/smithy-client` `send` subscriber with AWS Bedrock Middleware by amychisholm03 · Pull Request #3864 · newrelic/node-newrelic

amychisholm03 · 2026-03-25T19:17:41Z

Description

This PR migrates the AWS Bedrock instrumentation from the shim-based (monkey-patching) architecture to the subscriber-based architecture.

A standalone bedrock middleware module (lib/subscribers/aws-sdk-v3/bedrock.js) exports an init/middleware/config object that creates segments, sets tracing context, and records LLM events for Bedrock API calls. The SmithyClientSendSubscriber in lib/subscribers/smithy-client/send.js uses a middlewareByClient dispatch map to register this bedrock middleware (plus common header/attribute middleware) when it detects a BedrockRuntime client.

To avoid double instrumentation during us refactoring the other AWS middlewares, the subscriber skips clients not in middlewareByClient, and the old shim in lib/instrumentation/aws-sdk/v3/smithy-client.js skips clients that the subscriber handles. This lets bedrock use the new subscriber path while all other AWS services (SNS, SQS, DynamoDB, Lambda) continue using the existing shim path.

Note: @aws-sdk/smithy-client just exports @smithy/smithy-client, so we only need to subscribe to the later.

How to Test

npm run versioned aws-sdk-v3

Related Issues

Closes #3839

Additional Info

To migrate another service (e.g., SNS, SQS, DynamoDB, Lambda):

Create a middleware config module in lib/subscribers/aws-sdk-v3/<service>.js exporting { init, middleware, config } — use bedrock.js as the template
Import it in send.js and add the client name to the middlewareByClient map (e.g., SNS: [snsMiddlewareConfig])
Add the client name to subscriberHandledClients in lib/instrumentation/aws-sdk/v3/smithy-client.js, so the old shim skips it
Once all services are migrated, the old shim and subscriberHandledClients set can be removed entirely

codecov · 2026-03-25T21:10:03Z

Codecov Report

❌ Patch coverage is 96.67250% with 19 lines in your changes missing coverage. Please review.
✅ Project coverage is 97.69%. Comparing base (83adcc4) to head (7dbd716).

Files with missing lines	Patch %	Lines
...ib/subscribers/aws-sdk/middleware/bedrock/index.js	95.91%	15 Missing ⚠️
lib/subscribers/aws-sdk/send.js	97.10%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3864      +/-   ##
==========================================
- Coverage   97.82%   97.69%   -0.13%     
==========================================
  Files         471      473       +2     
  Lines       58670    58830     +160     
  Branches        1        1              
==========================================
+ Hits        57391    57472      +81     
- Misses       1279     1358      +79

Flag	Coverage Δ
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jsumners-nr

I have not looked at the code yet. I want address organization first. I understand the thinking behind lib/subscribers/smithy-client/ and lib/subscribers/aws-sdk-v3/. But I think that will lead to some difficulty in understanding where things are when reviewing things in the future.

I'd like to suggest we organize things as so:

lib/subscribers/aws-sdk/
lib/subscribers/aws-sdk/v3/
lib/subscribers/aws-sdk/v3/bedrock.js
lib/subscribers/aws-sdk/smithy-client/

bizob2828 · 2026-03-26T13:19:48Z

I have not looked at the code yet. I want address organization first. I understand the thinking behind lib/subscribers/smithy-client/ and lib/subscribers/aws-sdk-v3/. But I think that will lead to some difficulty in understanding where things are when reviewing things in the future.

I'd like to suggest we organize things as so:

lib/subscribers/aws-sdk/

lib/subscribers/aws-sdk/v3/

lib/subscribers/aws-sdk/v3/bedrock.js

lib/subscribers/aws-sdk/smithy-client/

technically the only subscriber is smithy-client. The rest are middleware/helpers.

jsumners-nr · 2026-03-26T13:31:14Z

I have not looked at the code yet. I want address organization first. I understand the thinking behind lib/subscribers/smithy-client/ and lib/subscribers/aws-sdk-v3/. But I think that will lead to some difficulty in understanding where things are when reviewing things in the future.
I'd like to suggest we organize things as so:

lib/subscribers/aws-sdk/

lib/subscribers/aws-sdk/v3/

lib/subscribers/aws-sdk/v3/bedrock.js

lib/subscribers/aws-sdk/smithy-client/

technically the only subscriber is smithy-client. The rest are middleware/helpers.

Do you disagree with my suggestion?

bizob2828 · 2026-03-26T14:03:27Z

I have not looked at the code yet. I want address organization first. I understand the thinking behind lib/subscribers/smithy-client/ and lib/subscribers/aws-sdk-v3/. But I think that will lead to some difficulty in understanding where things are when reviewing things in the future.
I'd like to suggest we organize things as so:

lib/subscribers/aws-sdk/

lib/subscribers/aws-sdk/v3/

lib/subscribers/aws-sdk/v3/bedrock.js

lib/subscribers/aws-sdk/smithy-client/

technically the only subscriber is smithy-client. The rest are middleware/helpers.

Do you disagree with my suggestion?

Not really. Looking at the current code, I could see the structure as this:

lib/subscribers/aws-sdk - config.js, smithy-client.js
lib/subsribers/aws-sdk/middleware- common, dynamodb, lambda, sns, sqs
lib/subscribers/aws-sdk/middleware/bedrock - index.js(current middleware), converse-stream-handler.js, stream-handler.js

Not wedded to this but that's my take on it. No need for v3 as we will not be supporting v2. Put all the middleware in a middleware folder. Expand bedrock to a folder as there are helpers for instrumenting streams.

bizob2828 · 2026-03-26T14:05:11Z

lib/subscribers/aws-sdk/config.js

+    },
+    {
+      channelName: 'nr_send',
+      module: { name: '@smithy/smithy-client', versionRange: '>=1.0.0 <4.0.0', filePath: 'dist-es/index.js' },


is @aws-sdk/smithy-client no longer valid? We were instrumenting that before

Like I said in my PR description, @aws-sdk/smithy-client is like a 3-liner package that just exports @smithy/smithy-client, so we only need to subscribe to the later.

Does it do so across all versions of these libraries that we support?

For npm run versioned aws-sdk-v3 it appears so.

I'll test more versions with AGENT_PATH="$(pwd)" ./node_modules/.bin/versioned-tests --patch --print pretty -i 100 --all --strict test/versioned/aws-sdk-v3

According to our tests:

node-newrelic/test/versioned/aws-sdk-v3/package.json

Line 11 in 83adcc4

{"name": "@aws-sdk/smithy-client", "minSupported": "3.47.0", "minAgentVersion": "8.7.1"},

The minimum version of @aws-sdk/smithy-client we support is 3.47.0. That version's manifest does not reference @smithy/smithy-client:

https://npmx.dev/package-code/@aws-sdk/smithy-client/v/3.47.0/package.json#L21-L25

At least for @aws-sdk/client-bedrock-runtime >=3.474.0, it does not have @aws-sdk/smithy-client as a dependency, only @smithy/smithy-client. Now with other @aws-sdk/* packages, there may be older versions that used @aws-sdk/smithy-client and adding the subscriber config for that could be addressed in that future PR.

Are you saying that the subscriber implementation only works with @aws-sdk/* >= v3.474.0?

No, the smithy client subscriber should instrument Client.send (or _Client.send depending on version) for @smithy/smithy-client: >=1, but it is only being tested currently with the AWS Bedrock middleware which is @aws-sdk/client-bedrock-runtime versions >=3.474.

Okay, I can't see any direct dependents of 3.47 that we are concerned with. So maybe this isn't a problem.

test/unit/instrumentation/aws-sdk/converse-stream-handler.test.js

test/unit/instrumentation/aws-sdk/stream-handler.test.js

amychisholm03 · 2026-03-26T14:57:29Z

I have not looked at the code yet. I want address organization first. I understand the thinking behind lib/subscribers/smithy-client/ and lib/subscribers/aws-sdk-v3/. But I think that will lead to some difficulty in understanding where things are when reviewing things in the future.
I'd like to suggest we organize things as so:

lib/subscribers/aws-sdk/

lib/subscribers/aws-sdk/v3/

lib/subscribers/aws-sdk/v3/bedrock.js

lib/subscribers/aws-sdk/smithy-client/

technically the only subscriber is smithy-client. The rest are middleware/helpers.

Do you disagree with my suggestion?

Not really. Looking at the current code, I could see the structure as this:

lib/subscribers/aws-sdk - config.js, smithy-client.js

lib/subsribers/aws-sdk/middleware- common, dynamodb, lambda, sns, sqs

lib/subscribers/aws-sdk/middleware/bedrock - index.js(current middleware), converse-stream-handler.js, stream-handler.js

Not wedded to this but that's my take on it. No need for v3 as we will not be supporting v2. Put all the middleware in a middleware folder. Expand bedrock to a folder as there are helpers for instrumenting streams.

Makes sense - I did aws-sdk-v3 to maintain parity with versioned test folder names. Also, I thought it may be confusing if @smithy/smithy-client was in a folder that wasn't smithy, but I could always add comments.

… integration

lib/subscribers/aws-sdk/config.js

lib/subscribers/aws-sdk/middleware/bedrock/index.js

bizob2828 · 2026-03-27T18:52:06Z

lib/subscribers/aws-sdk/middleware/bedrock/index.js

+
+    // Enter the segment's context so downstream middleware (e.g. HTTP outbound)
+    // creates child segments under this bedrock segment.
+    agent.tracer.setSegment({ segment })


you want to avoid manually setting the context. This wrapped middleware should follow our standard processes where you bind the original next function to the context via agent.tracer.bindFunction(next, ctx, true).apply(this, arguments) and then run your afterHookstuff. also by passing intrue`. it will start the function and touch it

github-project-automation bot added this to Node.js Engineering Board Mar 25, 2026

newrelic-node-agent-team moved this to Needs PR Review in Node.js Engineering Board Mar 25, 2026

amychisholm03 force-pushed the NR-3839/aws-bedrock-migration branch from f34d803 to 61a01a7 Compare March 25, 2026 20:32

amychisholm03 changed the title ~~refactor: @smithy/smithy-client send subscriber with AWS Bedrock Middleware~~ refactor: Added @smithy/smithy-client send subscriber with AWS Bedrock Middleware Mar 25, 2026

amychisholm03 marked this pull request as ready for review March 25, 2026 22:15

jsumners-nr requested changes Mar 26, 2026

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bizob2828 reviewed Mar 26, 2026

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amychisholm03 added 2 commits March 26, 2026 08:13

@smithy/smithy-client send subscriber with AWS Bedrock Middleware…

862ecb4

… integration

fix unit tests

3321397

amychisholm03 force-pushed the NR-3839/aws-bedrock-migration branch from 4058bca to 9a98df1 Compare March 26, 2026 15:13

Fix organization

bc42729

amychisholm03 force-pushed the NR-3839/aws-bedrock-migration branch from f7a7ad5 to bc42729 Compare March 26, 2026 16:01

jsumners-nr reviewed Mar 26, 2026

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Address PR feedback for middleware/bedrock/index.js

7dbd716

amychisholm03 requested a review from bizob2828 March 26, 2026 20:39

bizob2828 reviewed Mar 27, 2026

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Use bindFunction

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