Home Docs Claude Developer Platform 10 Nov 2026

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sdk changedmanage-claude/opentelemetry/sdk

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Recorded here 10 Nov 2026 04:37 UTC

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From line 256 where the diff opens

First seen 14 Oct 2026 this site's first read of the page

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### Identify your end users

The whole hunk

from line 256, old and new numbered

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from line 256

256256 defer provider.Shutdown(ctx)

257257 otel.SetTracerProvider(provider)

258258 // OpenTelemetry for Go doesn't register a propagator by default, so

259 // register the W3C trace context propagator.

260 otel.SetTextMapPropagator(propagation.TraceContext{})

259 // register the W3C trace context and baggage propagators.

260 otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{}))

261261

262262 client := anthropic.NewClient()

263263

from line 279

279279 import com.anthropic.client.okhttp.AnthropicOkHttpClient;

280280 import com.anthropic.models.messages.MessageCreateParams;

281281 import com.anthropic.models.messages.Model;

282 import io.opentelemetry.api.baggage.propagation.W3CBaggagePropagator;

282283 import io.opentelemetry.api.trace.propagation.W3CTraceContextPropagator;

283284 import io.opentelemetry.context.propagation.ContextPropagators;

285 import io.opentelemetry.context.propagation.TextMapPropagator;

284286 import io.opentelemetry.exporter.logging.LoggingSpanExporter;

285287 import io.opentelemetry.sdk.OpenTelemetrySdk;

286288 import io.opentelemetry.sdk.trace.SdkTracerProvider;

from line 296

294296 OpenTelemetrySdk.builder()

295297 .setTracerProvider(tracerProvider)

296298 // OpenTelemetry for Java doesn't register a propagator when you build

297 // it in code, so register the W3C trace context propagator.

298 .setPropagators(ContextPropagators.create(W3CTraceContextPropagator.getInstance()))

299 // it in code, so register the W3C trace context and baggage propagators.

300 .setPropagators(ContextPropagators.create(TextMapPropagator.composite(

301 W3CTraceContextPropagator.getInstance(), W3CBaggagePropagator.getInstance())))

299302 .buildAndRegisterGlobal();

300303

301304 var client = AnthropicOkHttpClient.fromEnv();

from line 317

314317 ```php PHP

315318 use Anthropic\Client;

316319 use Anthropic\Messages\Model;

320 use OpenTelemetry\API\Baggage\Propagation\BaggagePropagator;

317321 use OpenTelemetry\API\Trace\Propagation\TraceContextPropagator;

322 use OpenTelemetry\Context\Propagation\MultiTextMapPropagator;

318323 use OpenTelemetry\SDK\Sdk;

319324 use OpenTelemetry\SDK\Trace\SpanExporter\ConsoleSpanExporterFactory;

320325 use OpenTelemetry\SDK\Trace\SpanProcessor\SimpleSpanProcessor;

from line 332

327332 Sdk::builder()

328333 ->setTracerProvider($tracerProvider)

329334 // OpenTelemetry for PHP doesn't register a propagator when you build

330 // it in code, so register the W3C trace context propagator.

331 ->setPropagator(TraceContextPropagator::getInstance())

335 // it in code, so register the W3C trace context and baggage propagators.

336 ->setPropagator(new MultiTextMapPropagator([

337 TraceContextPropagator::getInstance(),

338 BaggagePropagator::getInstance(),

339 ]))

332340 ->buildAndRegisterGlobal();

333341

334342 $client = new Client();

from line 602

594602

595603## Trace context and baggage

596604

597With each request, the SDK uses your application’s propagator to send the trace context to the API in headers such as `traceparent`. If that propagator also writes baggage, the SDK sends your baggage too. To send the trace context without baggage, register only the W3C trace context propagator.

605With each request, the SDK uses your application’s propagator to send the trace context to the API in headers such as `traceparent`. If that propagator also writes baggage, the SDK sends your baggage too, which is how you can [identify your end users](https://platform.claude.com/docs/en/manage-claude/opentelemetry/sdk#identify-your-end-users). To send the trace context without baggage, register only the W3C trace context propagator.

598606

599607To stop the SDK from sending these headers, for example when your HTTP client instrumentation already sends them, turn off the SDK’s propagation:

600608

from line 676

668676</CodeGroup>

669677

670678While the SDK calls an [MCP tool](https://platform.claude.com/docs/en/agents-and-tools/mcp-connector#client-side-mcp-helpers), the SDK’s tool span is the current span. Some MCP client libraries send the trace context to the MCP server in `_meta`, so a server that reads it can add its spans to your trace under that tool span. The Python `mcp` package from version 2.0 and the C# `ModelContextProtocol` package do this. The TypeScript, Go, Java, Ruby, and PHP MCP SDKs don’t do it on their own.

679

680### Identify your end users

681

682[Baggage](https://opentelemetry.io/docs/concepts/signals/baggage/) is a set of key-value pairs that a request carries in its W3C `baggage` header. To set the [`user.id`](https://platform.claude.com/docs/en/api/opentelemetry/spans#user.id) attribute on the API spans for a request, send the request with a `user.id` baggage entry set to your end user’s ID. Use an opaque ID, not an email address: to protect user privacy, the API drops any `user.id` that contains one.

683

684<CodeGroup>

685 ```bash cURL

686 curl https://api.anthropic.com/v1/messages \

687 -H "x-api-key: $ANTHROPIC_API_KEY" \

688 -H "anthropic-version: 2026-10-21" \

689 -H "content-type: application/json" \

690 -H "baggage: user.id=4f2a" \

691 -d '{

692 "model": "claude-opus-5-5",

693 "max_tokens": 1024,

694 "messages": [

695 {"role": "user", "content": "Hello, Claude"}

696 ]

697 }'

698 ```

699

700 ```bash CLI

701 ANTHROPIC_CUSTOM_HEADERS="baggage: user.id=4f2a" ant messages create \

702 --model claude-opus-5-5 \

703 --max-tokens 1024 \

704 --message '{role: user, content: "Hello, Claude"}'

705 ```

706

707 ```python Python

708 from opentelemetry import baggage, context

709

710 client = Anthropic()

711

712 token = context.attach(baggage.set_baggage("user.id", "4f2a"))

713 try:

714 message = client.messages.create(

715 model="claude-opus-5-5",

716 max_tokens=1024,

717 messages=[{"role": "user", "content": "Hello, Claude"}],

718 )

719 finally:

720 context.detach(token)

721 ```

722

723 ```typescript TypeScript

724 import { context, propagation } from "@opentelemetry/api";

725

726 const client = new Anthropic();

727

728 const userBaggage = propagation.createBaggage({ "user.id": { value: "4f2a" } });

729 const message = await context.with(propagation.setBaggage(context.active(), userBaggage), () =>

730 client.messages.create({

731 model: "claude-opus-5-5",

732 max_tokens: 1024,

733 messages: [{ role: "user", content: "Hello, Claude" }]

734 })

735 );

736 ```

737

738 ```csharp C#

739 using System.Diagnostics;

740 // ...

741 // Register this source with AddSource on your tracer provider, so that it records the activity.

742 ActivitySource source = new("MyApp");

743 AnthropicClient client = new();

744

745 // The SDK sends the current activity's baggage.

746 using var activity = source.StartActivity("chat");

747 activity?.SetBaggage("user.id", "4f2a");

748 var message = await client.Messages.Create(new MessageCreateParams

749 {

750 Model = Model.ClaudeOpus5_5,

751 MaxTokens = 1024,

752 Messages = [new UserMessageParam { Content = "Hello, Claude" }],

753 });

754 ```

755

756 ```go Go

757 client := anthropic.NewClient()

758

759 member, _ := baggage.NewMember("user.id", "4f2a")

760 userBaggage, _ := baggage.New(member)

761 ctx := baggage.ContextWithBaggage(context.Background(), userBaggage)

762 message, err := client.Messages.New(ctx, anthropic.MessageNewParams{

763 Model: anthropic.ModelClaudeOpus5_5,

764 MaxTokens: 1024,

765 Messages: []anthropic.MessageParam{

766 anthropic.NewUserMessage(anthropic.NewTextBlock("Hello, Claude")),

767 },

768 })

769 ```

770

771 ```java Java

772 import io.opentelemetry.api.baggage.Baggage;

773

774 void main() {

775 var client = AnthropicOkHttpClient.fromEnv();

776

777 try (var scope = Baggage.current().toBuilder().put("user.id", "4f2a").build().makeCurrent()) {

778 var message = client.messages().create(MessageCreateParams.builder()

779 .model(Model.CLAUDE_OPUS_5_5)

780 .maxTokens(1024)

781 .addUserMessage("Hello, Claude")

782 .build());

783 }

784 }

785 ```

786

787 ```php PHP

788 use OpenTelemetry\API\Baggage\Baggage;

789

790 $client = new Client();

791

792 $scope = Baggage::getBuilder()->set('user.id', '4f2a')->build()->activate();

793 try {

794 $message = $client->messages->create(

795 maxTokens: 1024,

796 messages: [['role' => 'user', 'content' => 'Hello, Claude']],

797 model: Model::CLAUDE_OPUS_5_5,

798 );

799 } finally {

800 $scope->detach();

801 }

802 ```

803

804 ```ruby Ruby

805 require "opentelemetry/sdk"

806

807 client = Anthropic::Client.new

808

809 OpenTelemetry::Context.with_current(OpenTelemetry::Baggage.set_value("user.id", "4f2a")) do

810 client.messages.create(

811 model: Anthropic::Model::CLAUDE_OPUS_5_5,

812 max_tokens: 1024,

813 messages: [{role: "user", content: "Hello, Claude"}]

814 )

815 end

816 ```

817</CodeGroup>

671818

672819## Troubleshooting

673820

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