chore: import upstream snapshot with attribution

dotnet/samples/03-workflows/Observability/ApplicationInsights/ApplicationInsights.csproj

@@ -0,0 +1,24 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFrameworks>net10.0</TargetFrameworks>
+
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Azure.Monitor.OpenTelemetry.Exporter" />
+    <PackageReference Include="OpenTelemetry" />
+  </ItemGroup>
+
+  <ItemGroup Condition="!$([MSBuild]::IsTargetFrameworkCompatible($(TargetFramework), 'net10.0'))">
+    <PackageReference Include="System.Diagnostics.DiagnosticSource" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\..\..\src\Microsoft.Agents.AI.Workflows\Microsoft.Agents.AI.Workflows.csproj" />
+  </ItemGroup>
+
+</Project>

dotnet/samples/03-workflows/Observability/ApplicationInsights/Program.cs

@@ -0,0 +1,118 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.Diagnostics;
+using Azure.Monitor.OpenTelemetry.Exporter;
+using Microsoft.Agents.AI.Workflows;
+using OpenTelemetry;
+using OpenTelemetry.Resources;
+using OpenTelemetry.Trace;
+
+namespace WorkflowObservabilitySample;
+
+/// <summary>
+/// This sample shows how to enable observability in a workflow and send the traces
+/// to be visualized in Application Insights.
+///
+/// In this example, we create a simple text processing pipeline that:
+/// 1. Takes input text and converts it to uppercase using an UppercaseExecutor
+/// 2. Takes the uppercase text and reverses it using a ReverseTextExecutor
+///
+/// The executors are connected sequentially, so data flows from one to the next in order.
+/// For input "Hello, World!", the workflow produces "!DLROW ,OLLEH".
+/// </summary>
+public static class Program
+{
+    private const string SourceName = "Workflow.ApplicationInsightsSample";
+    private static readonly ActivitySource s_activitySource = new(SourceName);
+
+    private static async Task Main()
+    {
+        var applicationInsightsConnectionString = Environment.GetEnvironmentVariable("APPLICATIONINSIGHTS_CONNECTION_STRING") ?? throw new InvalidOperationException("APPLICATIONINSIGHTS_CONNECTION_STRING is not set.");
+
+        var resourceBuilder = ResourceBuilder
+            .CreateDefault()
+            .AddService("WorkflowSample");
+
+        using var traceProvider = Sdk.CreateTracerProviderBuilder()
+            .SetResourceBuilder(resourceBuilder)
+            .AddSource(SourceName)
+            // The following source is only required if not specifying
+            // the `activitySource` in the WithOpenTelemetry call below
+            .AddSource("Microsoft.Agents.AI.Workflows*")
+            .AddAzureMonitorTraceExporter(options => options.ConnectionString = applicationInsightsConnectionString)
+            .Build();
+
+        // Start a root activity for the application
+        using var activity = s_activitySource.StartActivity("main");
+        Console.WriteLine($"Operation/Trace ID: {Activity.Current?.TraceId}");
+
+        // Create the executors
+        UppercaseExecutor uppercase = new();
+        ReverseTextExecutor reverse = new();
+
+        // Build the workflow by connecting executors sequentially
+        var workflow = new WorkflowBuilder(uppercase)
+            .AddEdge(uppercase, reverse)
+            .WithOpenTelemetry(
+                // Set `EnableSensitiveData` to true to include message content in traces
+                configure: cfg => cfg.EnableSensitiveData = true,
+                activitySource: s_activitySource)
+            .Build();
+
+        // Execute the workflow with input data
+        Run run = await InProcessExecution.RunAsync(workflow, "Hello, World!");
+        foreach (WorkflowEvent evt in run.NewEvents)
+        {
+            if (evt is ExecutorCompletedEvent executorComplete)
+            {
+                Console.WriteLine($"{executorComplete.ExecutorId}: {executorComplete.Data}");
+            }
+            else if (evt is WorkflowErrorEvent workflowError)
+            {
+                Console.ForegroundColor = ConsoleColor.Red;
+                Console.Error.WriteLine(workflowError.Exception?.ToString() ?? "Unknown workflow error occurred.");
+                Console.ResetColor();
+            }
+            else if (evt is ExecutorFailedEvent executorFailed)
+            {
+                Console.ForegroundColor = ConsoleColor.Red;
+                Console.Error.WriteLine($"Executor '{executorFailed.ExecutorId}' failed with {(executorFailed.Data == null ? "unknown error" : $"exception {executorFailed.Data}")}.");
+                Console.ResetColor();
+            }
+        }
+    }
+}
+
+/// <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) =>
+        message.ToUpperInvariant(); // The return value will be sent as a message along an edge to subsequent executors
+}
+
+/// <summary>
+/// Second executor: reverses the input text and completes the workflow.
+/// </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)
+        => new(message.Reverse().ToArray());
+}

dotnet/samples/03-workflows/Observability/AspireDashboard/AspireDashboard.csproj

@@ -0,0 +1,25 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFrameworks>net10.0</TargetFrameworks>
+
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="OpenTelemetry" />
+    <PackageReference Include="OpenTelemetry.Exporter.Console" />
+    <PackageReference Include="OpenTelemetry.Exporter.OpenTelemetryProtocol" />
+  </ItemGroup>
+
+  <ItemGroup Condition="!$([MSBuild]::IsTargetFrameworkCompatible($(TargetFramework), 'net10.0'))">
+    <PackageReference Include="System.Diagnostics.DiagnosticSource" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\..\..\src\Microsoft.Agents.AI.Workflows\Microsoft.Agents.AI.Workflows.csproj" />
+  </ItemGroup>
+
+</Project>

dotnet/samples/03-workflows/Observability/AspireDashboard/Program.cs

@@ -0,0 +1,120 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.Diagnostics;
+using Microsoft.Agents.AI.Workflows;
+using OpenTelemetry;
+using OpenTelemetry.Logs;
+using OpenTelemetry.Metrics;
+using OpenTelemetry.Resources;
+using OpenTelemetry.Trace;
+
+namespace WorkflowObservabilitySample;
+
+/// <summary>
+/// This sample shows how to enable observability in a workflow and send the traces
+/// to be visualized in Aspire Dashboard.
+///
+/// In this example, we create a simple text processing pipeline that:
+/// 1. Takes input text and converts it to uppercase using an UppercaseExecutor
+/// 2. Takes the uppercase text and reverses it using a ReverseTextExecutor
+///
+/// The executors are connected sequentially, so data flows from one to the next in order.
+/// For input "Hello, World!", the workflow produces "!DLROW ,OLLEH".
+/// </summary>
+public static class Program
+{
+    private const string SourceName = "Workflow.Sample";
+    private static readonly ActivitySource s_activitySource = new(SourceName);
+
+    private static async Task Main()
+    {
+        // Configure OpenTelemetry for Aspire dashboard
+        var otlpEndpoint = Environment.GetEnvironmentVariable("OTEL_EXPORTER_OTLP_ENDPOINT") ?? "http://localhost:4317";
+
+        var resourceBuilder = ResourceBuilder
+            .CreateDefault()
+            .AddService("WorkflowSample");
+
+        using var traceProvider = Sdk.CreateTracerProviderBuilder()
+            .SetResourceBuilder(resourceBuilder)
+            .AddSource(SourceName)
+            // The following source is only required if not specifying
+            // the `activitySource` in the WithOpenTelemetry call below
+            .AddSource("Microsoft.Agents.AI.Workflows*")
+            .AddOtlpExporter(options => options.Endpoint = new Uri(otlpEndpoint))
+            .Build();
+
+        // Start a root activity for the application
+        using var activity = s_activitySource.StartActivity("main");
+        Console.WriteLine($"Operation/Trace ID: {Activity.Current?.TraceId}");
+
+        // Create the executors
+        UppercaseExecutor uppercase = new();
+        ReverseTextExecutor reverse = new();
+
+        // Build the workflow by connecting executors sequentially
+        var workflow = new WorkflowBuilder(uppercase)
+            .AddEdge(uppercase, reverse)
+            .WithOpenTelemetry(
+                // Set `EnableSensitiveData` to true to include message content in traces
+                configure: cfg => cfg.EnableSensitiveData = true,
+                activitySource: s_activitySource)
+            .Build();
+
+        // Execute the workflow with input data
+        await using Run run = await InProcessExecution.RunAsync(workflow, "Hello, World!");
+        foreach (WorkflowEvent evt in run.NewEvents)
+        {
+            if (evt is ExecutorCompletedEvent executorComplete)
+            {
+                Console.WriteLine($"{executorComplete.ExecutorId}: {executorComplete.Data}");
+            }
+            else if (evt is WorkflowErrorEvent workflowError)
+            {
+                Console.ForegroundColor = ConsoleColor.Red;
+                Console.Error.WriteLine(workflowError.Exception?.ToString() ?? "Unknown workflow error occurred.");
+                Console.ResetColor();
+            }
+            else if (evt is ExecutorFailedEvent executorFailed)
+            {
+                Console.ForegroundColor = ConsoleColor.Red;
+                Console.Error.WriteLine($"Executor '{executorFailed.ExecutorId}' failed with {(executorFailed.Data == null ? "unknown error" : $"exception {executorFailed.Data}")}.");
+                Console.ResetColor();
+            }
+        }
+    }
+}
+
+/// <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) =>
+        message.ToUpperInvariant(); // The return value will be sent as a message along an edge to subsequent executors
+}
+
+/// <summary>
+/// Second executor: reverses the input text and completes the workflow.
+/// </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)
+        => new(message.Reverse().ToArray());
+}

dotnet/samples/03-workflows/Observability/WorkflowAsAnAgent/Program.cs

@@ -0,0 +1,135 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.Diagnostics;
+using Azure.AI.Projects;
+using Azure.Identity;
+using Azure.Monitor.OpenTelemetry.Exporter;
+using Microsoft.Agents.AI;
+using Microsoft.Agents.AI.Workflows;
+using Microsoft.Extensions.AI;
+using OpenTelemetry;
+using OpenTelemetry.Resources;
+using OpenTelemetry.Trace;
+
+namespace WorkflowAsAnAgentObservabilitySample;
+
+/// <summary>
+/// This sample shows how to enable OpenTelemetry observability for workflows when
+/// using them as <see cref="AIAgent"/>s.
+///
+/// In this example, we create a workflow that uses two language agents to process
+/// input concurrently, one that responds in French and another that responds in English.
+///
+/// You will interact with the workflow in an interactive loop, sending messages and receiving
+/// streaming responses from the workflow as if it were an agent who responds in both languages.
+///
+/// OpenTelemetry observability is enabled at multiple levels:
+/// 1. At the chat client level, capturing telemetry for interactions with the Azure OpenAI service.
+/// 2. At the agent level, capturing telemetry for agent operations.
+/// 3. At the workflow level, capturing telemetry for workflow execution.
+///
+/// Traces will be sent to an Aspire dashboard via an OTLP endpoint, and optionally to
+/// Azure Monitor if an Application Insights connection string is provided.
+///
+/// Learn how to set up an Aspire dashboard here:
+/// https://learn.microsoft.com/en-us/dotnet/aspire/fundamentals/dashboard/standalone?tabs=bash
+/// </summary>
+/// <remarks>
+/// Pre-requisites:
+/// - Foundational samples should be completed first.
+/// - This sample uses concurrent processing.
+/// - An Azure OpenAI endpoint and deployment name.
+/// - An Application Insights resource for telemetry (optional).
+/// </remarks>
+public static class Program
+{
+    private const string SourceName = "Workflow.ApplicationInsightsSample";
+    private static readonly ActivitySource s_activitySource = new(SourceName);
+
+    private static async Task Main()
+    {
+        // Set up observability
+        var applicationInsightsConnectionString = Environment.GetEnvironmentVariable("APPLICATIONINSIGHTS_CONNECTION_STRING");
+        var otlpEndpoint = Environment.GetEnvironmentVariable("OTEL_EXPORTER_OTLP_ENDPOINT") ?? "http://localhost:4317";
+
+        var resourceBuilder = ResourceBuilder
+            .CreateDefault()
+            .AddService("WorkflowSample");
+
+        var traceProviderBuilder = Sdk.CreateTracerProviderBuilder()
+            .SetResourceBuilder(resourceBuilder)
+            .AddSource("Microsoft.Agents.AI.*") // Agent Framework telemetry
+            .AddSource("Microsoft.Extensions.AI.*") // Extensions AI telemetry
+            .AddSource(SourceName);
+
+        traceProviderBuilder.AddOtlpExporter(options => options.Endpoint = new Uri(otlpEndpoint));
+        if (!string.IsNullOrWhiteSpace(applicationInsightsConnectionString))
+        {
+            traceProviderBuilder.AddAzureMonitorTraceExporter(options => options.ConnectionString = applicationInsightsConnectionString);
+        }
+
+        using var traceProvider = traceProviderBuilder.Build();
+
+        // Set up the Azure AI Foundry client
+        var endpoint = Environment.GetEnvironmentVariable("FOUNDRY_PROJECT_ENDPOINT") ?? throw new InvalidOperationException("FOUNDRY_PROJECT_ENDPOINT is not set.");
+        var deploymentName = Environment.GetEnvironmentVariable("FOUNDRY_MODEL") ?? "gpt-5.4-mini";
+        AIProjectClient aiProjectClient = new(new Uri(endpoint), new DefaultAzureCredential());
+
+        // Start a root activity for the application
+        using var activity = s_activitySource.StartActivity("main");
+        Console.WriteLine($"Operation/Trace ID: {Activity.Current?.TraceId}");
+
+        // Create the workflow and turn it into an agent with OpenTelemetry instrumentation
+        var workflow = WorkflowHelper.GetWorkflow(aiProjectClient, deploymentName, SourceName);
+        var agent = new OpenTelemetryAgent(workflow.AsAIAgent("workflow-agent", "Workflow Agent"), SourceName)
+        {
+            EnableSensitiveData = true  // enable sensitive data at the agent level such as prompts and responses
+        };
+        var session = await agent.CreateSessionAsync();
+
+        // Start an interactive loop to interact with the workflow as if it were an agent
+        while (true)
+        {
+            Console.WriteLine();
+            Console.Write("User (or 'exit' to quit): ");
+            string? input = Console.ReadLine();
+            if (string.IsNullOrWhiteSpace(input) || input.Equals("exit", StringComparison.OrdinalIgnoreCase))
+            {
+                break;
+            }
+
+            await ProcessInputAsync(agent, session, input);
+        }
+
+        // Helper method to process user input and display streaming responses. To display
+        // multiple interleaved responses correctly, we buffer updates by message ID and
+        // re-render all messages on each update.
+        static async Task ProcessInputAsync(AIAgent agent, AgentSession? session, string input)
+        {
+            Dictionary<string, List<AgentResponseUpdate>> buffer = [];
+            await foreach (AgentResponseUpdate update in agent.RunStreamingAsync(input, session))
+            {
+                if (update.MessageId is null || string.IsNullOrEmpty(update.Text))
+                {
+                    // skip updates that don't have a message ID or text
+                    continue;
+                }
+                Console.Clear();
+
+                if (!buffer.TryGetValue(update.MessageId, out List<AgentResponseUpdate>? value))
+                {
+                    value = [];
+                    buffer[update.MessageId] = value;
+                }
+                value.Add(update);
+
+                foreach (var (messageId, segments) in buffer)
+                {
+                    string combinedText = string.Concat(segments);
+                    Console.WriteLine($"{segments[0].AuthorName}: {combinedText}");
+                    Console.WriteLine();
+                }
+            }
+        }
+    }
+}

dotnet/samples/03-workflows/Observability/WorkflowAsAnAgent/WorkflowAsAnAgentObservability.csproj

@@ -0,0 +1,31 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFrameworks>net10.0</TargetFrameworks>
+
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Azure.Identity" />
+    <PackageReference Include="Azure.Monitor.OpenTelemetry.Exporter" />
+    <PackageReference Include="OpenTelemetry" />
+    <PackageReference Include="OpenTelemetry.Exporter.OpenTelemetryProtocol" />
+  </ItemGroup>
+
+  <ItemGroup Condition="!$([MSBuild]::IsTargetFrameworkCompatible($(TargetFramework), 'net10.0'))">
+    <PackageReference Include="System.Diagnostics.DiagnosticSource" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\..\..\src\Microsoft.Agents.AI.Foundry\Microsoft.Agents.AI.Foundry.csproj" />
+    <ProjectReference Include="..\..\..\..\src\Microsoft.Agents.AI.Workflows\Microsoft.Agents.AI.Workflows.csproj" />
+    <ProjectReference Include="..\..\..\..\src\Microsoft.Agents.AI.Workflows.Generators\Microsoft.Agents.AI.Workflows.Generators.csproj"
+                      OutputItemType="Analyzer"
+                      ReferenceOutputAssembly="false" />
+    <ProjectReference Include="..\..\..\..\src\Microsoft.Agents.AI\Microsoft.Agents.AI.csproj" />
+  </ItemGroup>
+
+</Project>

dotnet/samples/03-workflows/Observability/WorkflowAsAnAgent/WorkflowHelper.cs

@@ -0,0 +1,113 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using Azure.AI.Projects;
+using Microsoft.Agents.AI;
+using Microsoft.Agents.AI.Workflows;
+using Microsoft.Extensions.AI;
+
+namespace WorkflowAsAnAgentObservabilitySample;
+
+internal static partial class WorkflowHelper
+{
+    /// <summary>
+    /// Creates a workflow that uses two language agents to process input concurrently.
+    /// </summary>
+    /// <param name="client">The AI project client to use for the agents</param>
+    /// <param name="model">The model deployment name</param>
+    /// <param name="sourceName">The source name for OpenTelemetry instrumentation</param>
+    /// <returns>A workflow that processes input using two language agents</returns>
+    internal static Workflow GetWorkflow(AIProjectClient client, string model, string sourceName)
+    {
+        // Create executors
+        var startExecutor = new ConcurrentStartExecutor();
+        var aggregationExecutor = new ConcurrentAggregationExecutor();
+        AIAgent frenchAgent = GetLanguageAgent("French", client, model, sourceName);
+        AIAgent englishAgent = GetLanguageAgent("English", client, model, sourceName);
+
+        // Build the workflow by adding executors and connecting them
+        return new WorkflowBuilder(startExecutor)
+            .AddFanOutEdge(startExecutor, [frenchAgent, englishAgent])
+            .AddFanInBarrierEdge([frenchAgent, englishAgent], aggregationExecutor)
+            .WithOutputFrom(aggregationExecutor)
+            .Build();
+    }
+
+    /// <summary>
+    /// Creates a language agent for the specified target language.
+    /// </summary>
+    /// <param name="targetLanguage">The target language for translation</param>
+    /// <param name="client">The AI project client to use for the agent</param>
+    /// <param name="model">The model deployment name</param>
+    /// <param name="sourceName">The source name for OpenTelemetry instrumentation</param>
+    /// <returns>An AIAgent configured for the specified language</returns>
+    private static AIAgent GetLanguageAgent(string targetLanguage, AIProjectClient client, string model, string sourceName) =>
+        client.AsAIAgent(
+            model: model,
+            instructions: $"You're a helpful assistant who always responds in {targetLanguage}.",
+            name: $"{targetLanguage}Agent",
+            clientFactory: c => c.AsBuilder()
+                .UseOpenTelemetry(sourceName: sourceName, configure: cfg => cfg.EnableSensitiveData = true)
+                .Build()
+        )
+        .AsBuilder()
+        .UseOpenTelemetry(sourceName, configure: (cfg) => cfg.EnableSensitiveData = true)   // enable telemetry at the agent level
+        .Build();
+
+    /// <summary>
+    /// Executor that starts the concurrent processing by sending messages to the agents.
+    /// </summary>
+    [SendsMessage(typeof(List<ChatMessage>))]
+    [SendsMessage(typeof(TurnToken))]
+    private sealed partial class ConcurrentStartExecutor()
+        : Executor("ConcurrentStartExecutor", declareCrossRunShareable: true), IResettableExecutor
+    {
+        [MessageHandler]
+        internal ValueTask RouteMessages(IEnumerable<ChatMessage> messages, IWorkflowContext context, CancellationToken cancellationToken)
+        {
+            List<ChatMessage> payload = messages as List<ChatMessage> ?? messages.ToList();
+            return context.SendMessageAsync(payload, cancellationToken: cancellationToken);
+        }
+
+        [MessageHandler]
+        internal ValueTask RouteTurnTokenAsync(TurnToken token, IWorkflowContext context, CancellationToken cancellationToken)
+        {
+            return context.SendMessageAsync(token, cancellationToken: cancellationToken);
+        }
+
+        public ValueTask ResetAsync() => default;
+    }
+
+    /// <summary>
+    /// Executor that aggregates the results from the concurrent agents.
+    /// </summary>
+    [YieldsOutput(typeof(string))]
+    private sealed partial class ConcurrentAggregationExecutor() :
+        Executor<List<ChatMessage>>("ConcurrentAggregationExecutor"), IResettableExecutor
+    {
+        private readonly List<ChatMessage> _messages = [];
+
+        /// <summary>
+        /// Handles incoming messages from the agents and aggregates their responses.
+        /// </summary>
+        /// <param name="message">The message from the agent</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>
+        public override async ValueTask HandleAsync(List<ChatMessage> message, IWorkflowContext context, CancellationToken cancellationToken = default)
+        {
+            this._messages.AddRange(message);
+
+            if (this._messages.Count == 2)
+            {
+                var formattedMessages = string.Join(Environment.NewLine, this._messages.Select(m => $"{m.Text}"));
+                await context.YieldOutputAsync(formattedMessages, cancellationToken);
+            }
+        }
+
+        public ValueTask ResetAsync()
+        {
+            this._messages.Clear();
+            return default;
+        }
+    }
+}