OpenTelemetry

OpenTelemetry: Distributed Tracing for Durable Chat

Overview

This sample shows how to configure distributed tracing for Temporalio.Extensions.AI, producing a complete span hierarchy from the external ChatAsync call through the Temporal protocol layers down to the LLM activity. It also demonstrates the DurableAIPlugin — the plugin-based registration path — as an alternative to AddDurableAI().

• Full span hierarchy: durable_chat.send → UpdateWorkflow:Chat → RunActivity:GetResponse → durable_chat.turn
• conversation.id attribute on both the send and turn spans — filter an entire session in one query
• Four ActivitySource names must be registered with the tracer provider
• TracingInterceptor propagates the W3C traceparent header across gRPC boundaries
• Plugin registration path: AddWorkerPlugin(new DurableAIPlugin(...)) as an alternative to AddDurableAI()

Span Hierarchy

durable_chat.send  (conversation.id = <id>)
  └─ UpdateWorkflow:Chat                     ← Temporal SDK protocol span
       └─ RunActivity:GetResponse            ← Temporal SDK protocol span
            └─ durable_chat.turn            ← library semantic span
                   conversation.id, gen_ai.usage.input_tokens,
                   gen_ai.usage.output_tokens

Highlights

• Four sources, not one. DurableChatTelemetry.ActivitySourceName covers library semantic spans; the three TracingInterceptor sources cover Temporal protocol spans. Omitting any one of them produces gaps in your trace.

  builder.Services
      .AddOpenTelemetry()
      .WithTracing(tracing => tracing
          .AddSource(DurableChatTelemetry.ActivitySourceName)
          .AddSource(TracingInterceptor.ClientSource.Name)
          .AddSource(TracingInterceptor.WorkflowsSource.Name)
          .AddSource(TracingInterceptor.ActivitiesSource.Name)
          .AddConsoleExporter());

• TracingInterceptor is required for connected traces. Without it, Temporal's internal gRPC calls break the distributed trace and the library spans appear disconnected from the protocol spans in your backend.

• conversation.id makes session filtering practical. Both the client-side durable_chat.send span and the worker-side durable_chat.turn span carry conversation.id, so a single attribute filter surfaces every span for a session across all service instances.

• DurableAIPlugin is the plugin entry point. Gated by [Experimental("TAI001")], it is equivalent to AddDurableAI() and follows the canonical Temporal AI Partner Ecosystem integration pattern. Suppress TAI001 with #pragma warning disable TAI001.

Getting Started

Prerequisites

• .NET 10 SDK or later
• A local Temporal server: temporal server start-dev
• An OpenAI-compatible API key

Configure API credentials

dotnet user-secrets set "OPENAI_API_KEY" "sk-..." --project samples/MEAI/OpenTelemetry
dotnet user-secrets set "OPENAI_API_BASE_URL" "https://api.openai.com/v1" --project samples/MEAI/OpenTelemetry

Run

dotnet run --project samples/MEAI/OpenTelemetry/DurableOpenTelemetry.csproj

Expected Output

Span data is written to the console by AddConsoleExporter(). Look for entries like:

Activity.DisplayName: durable_chat.send
    conversation.id: otel-demo-<guid>
Activity.DisplayName: durable_chat.turn
    conversation.id: otel-demo-<guid>
    gen_ai.usage.input_tokens: 42
    gen_ai.usage.output_tokens: 18

Filter by conversation.id = otel-demo-<guid> to see all spans for the session.