Add OpenTelemetry observability instrumentation to DurableTask workflows

- Add centralized DurableTaskInstrumentation class with shared ActivitySource
- Add workflow.run span to DurableWorkflowRunner (emitted after superstep loop to avoid replay semantics)
- Add edge_group.process spans to DurableDirectEdgeRouter and DurableFanOutEdgeRouter
- Add message.send span to DurableWorkflowContext
- Add TraceContext propagation support to DurableWorkflowContext
- Add 09_Observability sample for durable workflows with Azure Monitor + OTLP export
- Update CHANGELOG.md

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

dotnet/agent-framework-dotnet.slnx

@@ -54,6 +54,7 @@
     <Project Path="samples/Durable/Workflow/ConsoleApps/04_WorkflowAndAgents/04_WorkflowAndAgents.csproj" />
     <Project Path="samples/Durable/Workflow/ConsoleApps/05_WorkflowEvents/05_WorkflowEvents.csproj" />
     <Project Path="samples/Durable/Workflow/ConsoleApps/06_WorkflowSharedState/06_WorkflowSharedState.csproj" />
+    <Project Path="samples/Durable/Workflow/ConsoleApps/09_Observability/09_Observability.csproj" />
   </Folder>
   <Folder Name="/Samples/Durable/Workflows/AzureFunctions/">
     <Project Path="samples/Durable/Workflow/AzureFunctions/01_SequentialWorkflow/01_SequentialWorkflow.csproj" />
@@ -409,7 +410,6 @@
     <Project Path="src/Microsoft.Agents.AI.Abstractions/Microsoft.Agents.AI.Abstractions.csproj" />
     <Project Path="src/Microsoft.Agents.AI.AGUI/Microsoft.Agents.AI.AGUI.csproj" />
     <Project Path="src/Microsoft.Agents.AI.Anthropic/Microsoft.Agents.AI.Anthropic.csproj" />
-    <Project Path="src/Microsoft.Agents.AI.GitHub.Copilot/Microsoft.Agents.AI.GitHub.Copilot.csproj" />
     <Project Path="src/Microsoft.Agents.AI.AzureAI.Persistent/Microsoft.Agents.AI.AzureAI.Persistent.csproj" />
     <Project Path="src/Microsoft.Agents.AI.AzureAI/Microsoft.Agents.AI.AzureAI.csproj" />
     <Project Path="src/Microsoft.Agents.AI.CopilotStudio/Microsoft.Agents.AI.CopilotStudio.csproj" />
@@ -417,6 +417,7 @@
     <Project Path="src/Microsoft.Agents.AI.Declarative/Microsoft.Agents.AI.Declarative.csproj" />
     <Project Path="src/Microsoft.Agents.AI.DevUI/Microsoft.Agents.AI.DevUI.csproj" />
     <Project Path="src/Microsoft.Agents.AI.DurableTask/Microsoft.Agents.AI.DurableTask.csproj" />
+    <Project Path="src/Microsoft.Agents.AI.GitHub.Copilot/Microsoft.Agents.AI.GitHub.Copilot.csproj" />
     <Project Path="src/Microsoft.Agents.AI.Hosting.A2A.AspNetCore/Microsoft.Agents.AI.Hosting.A2A.AspNetCore.csproj" />
     <Project Path="src/Microsoft.Agents.AI.Hosting.A2A/Microsoft.Agents.AI.Hosting.A2A.csproj" />
     <Project Path="src/Microsoft.Agents.AI.Hosting.AGUI.AspNetCore/Microsoft.Agents.AI.Hosting.AGUI.AspNetCore.csproj" />
@@ -428,8 +429,8 @@
     <Project Path="src/Microsoft.Agents.AI.Purview/Microsoft.Agents.AI.Purview.csproj" />
     <Project Path="src/Microsoft.Agents.AI.Workflows.Declarative.AzureAI/Microsoft.Agents.AI.Workflows.Declarative.AzureAI.csproj" />
     <Project Path="src/Microsoft.Agents.AI.Workflows.Declarative/Microsoft.Agents.AI.Workflows.Declarative.csproj" />
-    <Project Path="src/Microsoft.Agents.AI.Workflows/Microsoft.Agents.AI.Workflows.csproj" />
     <Project Path="src/Microsoft.Agents.AI.Workflows.Generators/Microsoft.Agents.AI.Workflows.Generators.csproj" />
+    <Project Path="src/Microsoft.Agents.AI.Workflows/Microsoft.Agents.AI.Workflows.csproj" />
     <Project Path="src/Microsoft.Agents.AI/Microsoft.Agents.AI.csproj" />
   </Folder>
   <Folder Name="/Tests/" />
@@ -439,8 +440,8 @@
     <Project Path="tests/AzureAI.IntegrationTests/AzureAI.IntegrationTests.csproj" />
     <Project Path="tests/AzureAIAgentsPersistent.IntegrationTests/AzureAIAgentsPersistent.IntegrationTests.csproj" />
     <Project Path="tests/CopilotStudio.IntegrationTests/CopilotStudio.IntegrationTests.csproj" />
-    <Project Path="tests/Microsoft.Agents.AI.GitHub.Copilot.IntegrationTests/Microsoft.Agents.AI.GitHub.Copilot.IntegrationTests.csproj" />
     <Project Path="tests/Microsoft.Agents.AI.DurableTask.IntegrationTests/Microsoft.Agents.AI.DurableTask.IntegrationTests.csproj" />
+    <Project Path="tests/Microsoft.Agents.AI.GitHub.Copilot.IntegrationTests/Microsoft.Agents.AI.GitHub.Copilot.IntegrationTests.csproj" />
     <Project Path="tests/Microsoft.Agents.AI.Hosting.AGUI.AspNetCore.IntegrationTests/Microsoft.Agents.AI.Hosting.AGUI.AspNetCore.IntegrationTests.csproj" />
     <Project Path="tests/Microsoft.Agents.AI.Hosting.AzureFunctions.IntegrationTests/Microsoft.Agents.AI.Hosting.AzureFunctions.IntegrationTests.csproj" />
     <Project Path="tests/Microsoft.Agents.AI.Mem0.IntegrationTests/Microsoft.Agents.AI.Mem0.IntegrationTests.csproj" />
@@ -454,13 +455,13 @@
     <Project Path="tests/Microsoft.Agents.AI.Abstractions.UnitTests/Microsoft.Agents.AI.Abstractions.UnitTests.csproj" />
     <Project Path="tests/Microsoft.Agents.AI.AGUI.UnitTests/Microsoft.Agents.AI.AGUI.UnitTests.csproj" />
     <Project Path="tests/Microsoft.Agents.AI.Anthropic.UnitTests/Microsoft.Agents.AI.Anthropic.UnitTests.csproj" />
-    <Project Path="tests/Microsoft.Agents.AI.GitHub.Copilot.UnitTests/Microsoft.Agents.AI.GitHub.Copilot.UnitTests.csproj" />
     <Project Path="tests/Microsoft.Agents.AI.AzureAI.Persistent.UnitTests/Microsoft.Agents.AI.AzureAI.Persistent.UnitTests.csproj" />
     <Project Path="tests/Microsoft.Agents.AI.AzureAI.UnitTests/Microsoft.Agents.AI.AzureAI.UnitTests.csproj" />
     <Project Path="tests/Microsoft.Agents.AI.CosmosNoSql.UnitTests/Microsoft.Agents.AI.CosmosNoSql.UnitTests.csproj" />
     <Project Path="tests/Microsoft.Agents.AI.Declarative.UnitTests/Microsoft.Agents.AI.Declarative.UnitTests.csproj" />
     <Project Path="tests/Microsoft.Agents.AI.DevUI.UnitTests/Microsoft.Agents.AI.DevUI.UnitTests.csproj" />
     <Project Path="tests/Microsoft.Agents.AI.DurableTask.UnitTests/Microsoft.Agents.AI.DurableTask.UnitTests.csproj" />
+    <Project Path="tests/Microsoft.Agents.AI.GitHub.Copilot.UnitTests/Microsoft.Agents.AI.GitHub.Copilot.UnitTests.csproj" />
     <Project Path="tests/Microsoft.Agents.AI.Hosting.A2A.UnitTests/Microsoft.Agents.AI.Hosting.A2A.UnitTests.csproj" />
     <Project Path="tests/Microsoft.Agents.AI.Hosting.AGUI.AspNetCore.UnitTests/Microsoft.Agents.AI.Hosting.AGUI.AspNetCore.UnitTests.csproj" />
     <Project Path="tests/Microsoft.Agents.AI.Hosting.AzureFunctions.UnitTests/Microsoft.Agents.AI.Hosting.AzureFunctions.UnitTests.csproj" />

dotnet/samples/Durable/Workflow/ConsoleApps/09_Observability/09_Observability.csproj

@@ -0,0 +1,35 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFrameworks>net10.0</TargetFrameworks>
+    <OutputType>Exe</OutputType>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <AssemblyName>DurableWorkflowObservability</AssemblyName>
+    <RootNamespace>DurableWorkflowObservability</RootNamespace>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Azure.Identity" />
+    <PackageReference Include="Azure.Monitor.OpenTelemetry.Exporter" />
+    <PackageReference Include="Microsoft.DurableTask.Client.AzureManaged" />
+    <PackageReference Include="Microsoft.DurableTask.Worker.AzureManaged" />
+    <PackageReference Include="Microsoft.Extensions.Hosting" />
+    <PackageReference Include="OpenTelemetry" />
+    <PackageReference Include="OpenTelemetry.Exporter.OpenTelemetryProtocol" />
+  </ItemGroup>
+
+  <ItemGroup Condition="!$([MSBuild]::IsTargetFrameworkCompatible($(TargetFramework), 'net10.0'))">
+    <PackageReference Include="System.Diagnostics.DiagnosticSource" />
+  </ItemGroup>
+
+  <!-- Local projects that should be switched to package references when using the sample outside of this MAF repo -->
+  <!--
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Agents.AI.DurableTask" />
+    <PackageReference Include="Microsoft.Agents.AI.Workflows" />
+  </ItemGroup>
+  -->
+  <ItemGroup>
+    <ProjectReference Include="..\..\..\..\..\src\Microsoft.Agents.AI.DurableTask\Microsoft.Agents.AI.DurableTask.csproj" />
+  </ItemGroup>
+</Project>

dotnet/samples/Durable/Workflow/ConsoleApps/09_Observability/Program.cs

@@ -0,0 +1,140 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+// This sample demonstrates how to enable OpenTelemetry observability for durable workflows.
+// Traces are sent to an Aspire Dashboard via OTLP, and optionally to Azure Monitor
+// if an Application Insights connection string is provided.
+//
+// The workflow is a simple text processing pipeline:
+//   UppercaseExecutor -> ReverseTextExecutor
+//
+// For input "Hello, World!", the workflow produces "!DLROW ,OLLEH".
+//
+// OpenTelemetry captures traces at the workflow level (executor dispatch, edge routing)
+// and at the Durable Task level (orchestration replay, activity execution).
+//
+// Learn how to set up an Aspire dashboard here:
+// https://learn.microsoft.com/en-us/dotnet/aspire/fundamentals/dashboard/standalone?tabs=bash
+
+using System.Diagnostics;
+using Azure.Monitor.OpenTelemetry.Exporter;
+using DurableWorkflowObservability;
+using Microsoft.Agents.AI.DurableTask;
+using Microsoft.Agents.AI.DurableTask.Workflows;
+using Microsoft.Agents.AI.Workflows;
+using Microsoft.DurableTask.Client.AzureManaged;
+using Microsoft.DurableTask.Worker.AzureManaged;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+using OpenTelemetry;
+using OpenTelemetry.Resources;
+using OpenTelemetry.Trace;
+
+// ── Configuration ────────────────────────────────────────────────────────────
+string sourceName = "DurableWorkflow.ObservabilitySample";
+ActivitySource activitySource = new(sourceName);
+
+string dtsConnectionString = Environment.GetEnvironmentVariable("DURABLE_TASK_SCHEDULER_CONNECTION_STRING")
+    ?? "Endpoint=http://localhost:8080;TaskHub=default;Authentication=None";
+string? applicationInsightsConnectionString = Environment.GetEnvironmentVariable("APPLICATIONINSIGHTS_CONNECTION_STRING");
+string otlpEndpoint = Environment.GetEnvironmentVariable("OTLP_ENDPOINT") ?? "http://localhost:4317";
+
+// ── OpenTelemetry Setup ──────────────────────────────────────────────────────
+ResourceBuilder resourceBuilder = ResourceBuilder
+    .CreateDefault()
+    .AddService("DurableWorkflowObservabilitySample");
+
+TracerProviderBuilder traceProviderBuilder = Sdk.CreateTracerProviderBuilder()
+    .SetResourceBuilder(resourceBuilder)
+    .AddSource("Microsoft.Agents.AI.Workflows*") // Workflow-level telemetry (executors, edges)
+    .AddSource("Microsoft.Agents.AI.DurableTask*") // Durable workflow telemetry (orchestration, dispatch, routing)
+    .AddSource(sourceName)                        // Application-level telemetry
+    .AddOtlpExporter(options => options.Endpoint = new Uri(otlpEndpoint));
+
+// Optionally add Azure Monitor exporter if connection string is provided
+if (!string.IsNullOrWhiteSpace(applicationInsightsConnectionString))
+{
+    traceProviderBuilder.AddAzureMonitorTraceExporter(
+        options => options.ConnectionString = applicationInsightsConnectionString);
+}
+
+using TracerProvider? traceProvider = traceProviderBuilder.Build();
+
+// Start a root activity so all workflow spans are correlated under one trace
+using Activity? rootActivity = activitySource.StartActivity("main");
+Console.WriteLine($"Operation/Trace ID: {Activity.Current?.TraceId}");
+
+// ── Define executors and build the workflow ──────────────────────────────────
+UppercaseExecutor uppercase = new();
+ReverseTextExecutor reverse = new();
+
+Workflow textProcessing = new WorkflowBuilder(uppercase)
+    .WithName("TextProcessing")
+    .WithDescription("Convert text to uppercase then reverse it")
+    .AddEdge(uppercase, reverse)
+    .Build();
+
+// ── Configure the host with durable workflow support ─────────────────────────
+IHost host = Host.CreateDefaultBuilder(args)
+    .ConfigureLogging(logging => logging.SetMinimumLevel(LogLevel.Warning))
+    .ConfigureServices(services =>
+    {
+        services.ConfigureDurableWorkflows(
+            workflowOptions => workflowOptions.AddWorkflow(textProcessing),
+            workerBuilder: builder => builder.UseDurableTaskScheduler(dtsConnectionString),
+            clientBuilder: builder => builder.UseDurableTaskScheduler(dtsConnectionString));
+    })
+    .Build();
+
+await host.StartAsync();
+
+IWorkflowClient workflowClient = host.Services.GetRequiredService<IWorkflowClient>();
+
+// ── Interactive loop ─────────────────────────────────────────────────────────
+Console.WriteLine();
+Console.WriteLine("Durable Workflow Observability Sample");
+Console.WriteLine("Workflow: UppercaseExecutor -> ReverseTextExecutor");
+Console.WriteLine("Traces are exported via OTLP to: " + otlpEndpoint);
+if (!string.IsNullOrWhiteSpace(applicationInsightsConnectionString))
+{
+    Console.WriteLine("Traces are also exported to Azure Monitor (Application Insights).");
+}
+
+Console.WriteLine();
+Console.WriteLine("Enter text to process (or 'exit' to quit):");
+
+while (true)
+{
+    Console.Write("> ");
+    string? input = Console.ReadLine();
+    if (string.IsNullOrWhiteSpace(input) || input.Equals("exit", StringComparison.OrdinalIgnoreCase))
+    {
+        break;
+    }
+
+    try
+    {
+        // Create a child activity for each workflow invocation
+        using Activity? invocationActivity = activitySource.StartActivity("ProcessText");
+        invocationActivity?.SetTag("input.text", input);
+
+        Console.WriteLine($"Starting workflow for input: \"{input}\"...");
+
+        IAwaitableWorkflowRun run = (IAwaitableWorkflowRun)await workflowClient.RunAsync(textProcessing, input);
+        Console.WriteLine($"Run ID: {run.RunId}");
+
+        Console.WriteLine("Waiting for workflow to complete...");
+        string? result = await run.WaitForCompletionAsync<string>();
+
+        invocationActivity?.SetTag("output.text", result);
+        Console.WriteLine($"Result: {result}");
+    }
+    catch (Exception ex)
+    {
+        Console.WriteLine($"Error: {ex.Message}");
+    }
+
+    Console.WriteLine();
+}
+
+await host.StopAsync();

dotnet/samples/Durable/Workflow/ConsoleApps/09_Observability/README.md

@@ -0,0 +1,100 @@
+# Observability Sample
+
+This sample demonstrates how to enable **OpenTelemetry observability** for durable workflows. It shows how to capture and export traces from workflow execution, including executor dispatch, edge routing, and Durable Task orchestration replays.
+
+## Key Concepts Demonstrated
+
+- Configuring OpenTelemetry tracing for durable workflows
+- Subscribing to `Microsoft.Agents.AI.Workflows*` activity sources for workflow-level telemetry
+- Exporting traces via OTLP (for Aspire Dashboard)
+- Optionally exporting traces to Azure Monitor (Application Insights)
+- Correlating all workflow spans under a single trace ID
+
+## Overview
+
+The sample implements a simple text processing pipeline that runs as a durable workflow:
+
+```
+UppercaseExecutor --> ReverseTextExecutor
+```
+
+| Executor | Description |
+|----------|-------------|
+| UppercaseExecutor | Converts input text to uppercase |
+| ReverseTextExecutor | Reverses the text |
+
+For input `"Hello, World!"`, the workflow produces `"!DLROW ,OLLEH"`.
+
+## Observability Setup
+
+The sample configures OpenTelemetry to capture traces from:
+
+1. **Workflow-level telemetry** (`Microsoft.Agents.AI.Workflows*`): Captures executor execution, edge routing, and workflow lifecycle events.
+2. **Durable workflow telemetry** (`Microsoft.Agents.AI.DurableTask*`): Captures durable orchestration lifecycle, executor dispatch, and edge routing within the durable execution environment.
+3. **Application-level telemetry**: Custom spans for each workflow invocation with input/output tags.
+
+Traces are exported to:
+
+- **Aspire Dashboard** (default): Via OTLP exporter to `http://localhost:4317`
+- **Azure Monitor** (optional): If `APPLICATIONINSIGHTS_CONNECTION_STRING` is set
+
+## Environment Setup
+
+See the [README.md](../README.md) file in the parent directory for information on configuring the Durable Task Scheduler.
+
+### Aspire Dashboard
+
+To visualize traces, start an Aspire Dashboard:
+
+```bash
+docker run --rm -it -d -p 18888:18888 -p 4317:18889 --name aspire-dashboard mcr.microsoft.com/dotnet/aspire-dashboard:9.0
+```
+
+Then open `http://localhost:18888` in your browser.
+
+Learn more: [Aspire Dashboard Standalone](https://learn.microsoft.com/en-us/dotnet/aspire/fundamentals/dashboard/standalone?tabs=bash)
+
+## Environment Variables
+
+| Variable | Required | Description |
+|----------|----------|-------------|
+| `DURABLE_TASK_SCHEDULER_CONNECTION_STRING` | No | Connection string for the Durable Task Scheduler. Defaults to local emulator. |
+| `OTLP_ENDPOINT` | No | OTLP exporter endpoint. Defaults to `http://localhost:4317`. |
+| `APPLICATIONINSIGHTS_CONNECTION_STRING` | No | Application Insights connection string. If set, traces are also sent to Azure Monitor. |
+
+## Running the Sample
+
+```bash
+cd dotnet/samples/Durable/Workflow/ConsoleApps/09_Observability
+dotnet run --framework net10.0
+```
+
+### Sample Output
+
+```text
+Operation/Trace ID: abc123def456...
+
+Durable Workflow Observability Sample
+Workflow: UppercaseExecutor -> ReverseTextExecutor
+Traces are exported via OTLP to: http://localhost:4317
+
+Enter text to process (or 'exit' to quit):
+> Hello, World!
+Starting workflow for input: "Hello, World!"...
+Run ID: xyz789...
+Waiting for workflow to complete...
+  [UppercaseExecutor] Processing: "Hello, World!"
+  [UppercaseExecutor] Result: "HELLO, WORLD!"
+  [ReverseTextExecutor] Processing: "HELLO, WORLD!"
+  [ReverseTextExecutor] Result: "!DLROW ,OLLEH"
+Result: !DLROW ,OLLEH
+
+> exit
+```
+
+After running, open the Aspire Dashboard to view the trace. You will see spans for:
+
+- The root `main` activity
+- Individual `ProcessText` activities for each invocation
+- Workflow executor spans (UppercaseExecutor, ReverseTextExecutor)
+- Edge routing spans between executors

dotnet/samples/Durable/Workflow/ConsoleApps/09_Observability/TextProcessingExecutors.cs

@@ -0,0 +1,59 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using Microsoft.Agents.AI.Workflows;
+
+namespace DurableWorkflowObservability;
+
+/// <summary>
+/// First executor: converts input text to uppercase.
+/// </summary>
+internal sealed class UppercaseExecutor() : Executor<string, string>("UppercaseExecutor")
+{
+    /// <summary>
+    /// Processes the input message by converting it to uppercase.
+    /// </summary>
+    /// <param name="message">The input text to convert</param>
+    /// <param name="context">Workflow context for accessing workflow services and adding events</param>
+    /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests.
+    /// The default is <see cref="CancellationToken.None"/>.</param>
+    /// <returns>The input text converted to uppercase</returns>
+    public override async ValueTask<string> HandleAsync(string message, IWorkflowContext context, CancellationToken cancellationToken = default)
+    {
+        Console.WriteLine($"  [UppercaseExecutor] Processing: \"{message}\"");
+
+        // Simulate some processing time
+        await Task.Delay(TimeSpan.FromMilliseconds(100), cancellationToken);
+
+        string result = message.ToUpperInvariant();
+        Console.WriteLine($"  [UppercaseExecutor] Result: \"{result}\"");
+
+        return result;
+    }
+}
+
+/// <summary>
+/// Second executor: reverses the input text.
+/// </summary>
+internal sealed class ReverseTextExecutor() : Executor<string, string>("ReverseTextExecutor")
+{
+    /// <summary>
+    /// Processes the input message by reversing the text.
+    /// </summary>
+    /// <param name="message">The input text to reverse</param>
+    /// <param name="context">Workflow context for accessing workflow services and adding events</param>
+    /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests.
+    /// The default is <see cref="CancellationToken.None"/>.</param>
+    /// <returns>The input text reversed</returns>
+    public override async ValueTask<string> HandleAsync(string message, IWorkflowContext context, CancellationToken cancellationToken = default)
+    {
+        Console.WriteLine($"  [ReverseTextExecutor] Processing: \"{message}\"");
+
+        // Simulate some processing time
+        await Task.Delay(TimeSpan.FromMilliseconds(100), cancellationToken);
+
+        string result = new(message.Reverse().ToArray());
+        Console.WriteLine($"  [ReverseTextExecutor] Result: \"{result}\"");
+
+        return result;
+    }
+}

dotnet/src/Microsoft.Agents.AI.DurableTask/Workflows/DurableExecutorDispatcher.cs

@@ -43,6 +43,9 @@ internal static class DurableExecutorDispatcher
     {
         logger.LogDispatchingExecutor(executorInfo.ExecutorId, executorInfo.IsAgenticExecutor);
 
+        // Note: executor.process telemetry is emitted by core Executor.ExecuteAsync inside the
+        // activity worker. We don't duplicate it here because orchestration replay semantics
+        // make wrapping spans unreliable (context.IsReplaying is true at method entry).
         if (executorInfo.IsAgenticExecutor)
         {
             return await ExecuteAgentAsync(context, executorInfo, logger, envelope.Message).ConfigureAwait(true);

dotnet/src/Microsoft.Agents.AI.DurableTask/Workflows/DurableRunStatus.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft. All rights reserved.
+// Copyright (c) Microsoft. All rights reserved.
 
 namespace Microsoft.Agents.AI.DurableTask.Workflows;
 

dotnet/src/Microsoft.Agents.AI.DurableTask/Workflows/DurableWorkflowContext.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft. All rights reserved.
+// Copyright (c) Microsoft. All rights reserved.
 
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
@@ -33,10 +33,12 @@ internal sealed class DurableWorkflowContext : IWorkflowContext
     /// </summary>
     /// <param name="initialState">The shared state passed from the orchestration.</param>
     /// <param name="executor">The executor running in this context.</param>
-    internal DurableWorkflowContext(Dictionary<string, string>? initialState, Executor executor)
+    /// <param name="traceContext">Optional trace context for correlation.</param>
+    internal DurableWorkflowContext(Dictionary<string, string>? initialState, Executor executor, IReadOnlyDictionary<string, string>? traceContext = null)
     {
         this._executor = executor;
         this._initialState = initialState ?? [];
+        this.TraceContext = traceContext;
     }
 
     /// <summary>
@@ -87,6 +89,8 @@ internal sealed class DurableWorkflowContext : IWorkflowContext
     {
         if (message is not null)
         {
+            using Activity? activity = DurableWorkflowInstrumentation.ActivitySource.StartActivity("message.send", ActivityKind.Producer);
+
             Type messageType = message.GetType();
             this.SentMessages.Add(new TypedPayload
             {
@@ -269,7 +273,7 @@ internal sealed class DurableWorkflowContext : IWorkflowContext
     }
 
     /// <inheritdoc/>
-    public IReadOnlyDictionary<string, string>? TraceContext => null;
+    public IReadOnlyDictionary<string, string>? TraceContext { get; }
 
     /// <inheritdoc/>
     public bool ConcurrentRunsEnabled => false;

dotnet/src/Microsoft.Agents.AI.DurableTask/Workflows/DurableWorkflowInstrumentation.cs

@@ -0,0 +1,16 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.Diagnostics;
+
+namespace Microsoft.Agents.AI.DurableTask.Workflows;
+
+/// <summary>
+/// Provides centralized OpenTelemetry instrumentation for durable workflow execution.
+/// </summary>
+internal static class DurableWorkflowInstrumentation
+{
+    /// <summary>
+    /// The shared <see cref="ActivitySource"/> used by all durable workflow components.
+    /// </summary>
+    internal static readonly ActivitySource ActivitySource = new("Microsoft.Agents.AI.DurableTask.Workflows");
+}

dotnet/src/Microsoft.Agents.AI.DurableTask/Workflows/DurableWorkflowRunner.cs

@@ -44,6 +44,7 @@
 //  Superstep 5 — loop exits (no pending messages)
 //    GetFinalResult returns resultE
 
+using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
 using System.Text.Json;
 using Microsoft.Agents.AI.DurableTask.Workflows.EdgeRouters;
@@ -115,7 +116,23 @@ internal sealed class DurableWorkflowRunner
         // Extract input - the start executor determines the expected input type from its own InputTypes
         object input = workflowInput.Input;
 
-        return await RunSuperstepLoopAsync(context, workflow, edgeMap, input, logger).ConfigureAwait(true);
+        string result = await RunSuperstepLoopAsync(context, workflow, edgeMap, input, logger).ConfigureAwait(true);
+
+        // Emit the workflow.run span after the superstep loop completes.
+        // Durable Task orchestrations replay the method from the top, where context.IsReplaying
+        // is true. It only transitions to false during forward progress (after all cached activity
+        // results are replayed). By emitting here — after RunSuperstepLoopAsync — we are guaranteed
+        // to be in non-replay mode, so the span is always captured exactly once.
+        if (!context.IsReplaying)
+        {
+            using Activity? activity = DurableWorkflowInstrumentation.ActivitySource.StartActivity("workflow.run");
+            activity?.SetTag("workflow.id", workflow.StartExecutorId)
+                .SetTag("workflow.name", workflowName)
+                .SetTag("run.id", instanceId)
+                .AddEvent(new ActivityEvent("workflow.completed"));
+        }
+
+        return result;
     }
 
     private Workflow GetWorkflowOrThrow(string orchestrationName)

dotnet/src/Microsoft.Agents.AI.DurableTask/Workflows/EdgeRouters/DurableDirectEdgeRouter.cs

@@ -29,6 +29,7 @@
 //  Enqueue to
 //  D's queue
 
+using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
 using System.Text.Json;
 using Microsoft.Extensions.Logging;
@@ -84,6 +85,12 @@ internal sealed class DurableDirectEdgeRouter : IDurableEdgeRouter
         Dictionary<string, Queue<DurableMessageEnvelope>> messageQueues,
         ILogger logger)
     {
+        using Activity? activity = DurableWorkflowInstrumentation.ActivitySource.StartActivity("edge_group.process");
+        activity?
+            .SetTag("edge_group.type", nameof(DurableDirectEdgeRouter))
+            .SetTag("message.source_id", this._sourceId)
+            .SetTag("message.target_id", this._sinkId);
+
         if (this._condition is not null)
         {
             try
@@ -92,17 +99,23 @@ internal sealed class DurableDirectEdgeRouter : IDurableEdgeRouter
                 if (!this._condition(messageObj))
                 {
                     logger.LogEdgeConditionFalse(this._sourceId, this._sinkId);
+                    activity?.SetTag("edge_group.delivered", false)
+                        .SetTag("edge_group.delivery_status", "dropped condition false");
                     return;
                 }
             }
             catch (Exception ex)
             {
                 logger.LogEdgeConditionEvaluationFailed(ex, this._sourceId, this._sinkId);
+                activity?.SetTag("edge_group.delivered", false)
+                    .SetTag("edge_group.delivery_status", "exception");
                 return;
             }
         }
 
         logger.LogEdgeRoutingMessage(this._sourceId, this._sinkId);
+        activity?.SetTag("edge_group.delivered", true)
+            .SetTag("edge_group.delivery_status", "delivered");
         EnqueueMessage(messageQueues, this._sinkId, envelope);
     }
 

dotnet/src/Microsoft.Agents.AI.DurableTask/Workflows/EdgeRouters/DurableFanOutEdgeRouter.cs

@@ -19,6 +19,7 @@
 //  Each DirectRouter independently evaluates its condition,
 //  so resultB always reaches C, but only reaches D if NeedsReview is true.
 
+using System.Diagnostics;
 using Microsoft.Extensions.Logging;
 
 namespace Microsoft.Agents.AI.DurableTask.Workflows.EdgeRouters;
@@ -54,6 +55,11 @@ internal sealed class DurableFanOutEdgeRouter : IDurableEdgeRouter
         Dictionary<string, Queue<DurableMessageEnvelope>> messageQueues,
         ILogger logger)
     {
+        using Activity? activity = DurableWorkflowInstrumentation.ActivitySource.StartActivity("edge_group.process");
+        activity?
+            .SetTag("edge_group.type", nameof(DurableFanOutEdgeRouter))
+            .SetTag("message.source_id", this._sourceId);
+
         if (logger.IsEnabled(LogLevel.Debug))
         {
             logger.LogDebug("Fan-Out from {Source}: routing to {Count} targets", this._sourceId, this._targetRouters.Count);