.NET: [Feature Branch] Add basic durable workflow support

dotnet/agent-framework-dotnet.slnx

@@ -47,6 +47,11 @@
     <Project Path="samples/Durable/Agents/ConsoleApps/06_LongRunningTools/06_LongRunningTools.csproj" />
     <Project Path="samples/Durable/Agents/ConsoleApps/07_ReliableStreaming/07_ReliableStreaming.csproj" />
   </Folder>
+  <Folder Name="/Samples/Durable/Workflows/">
+    <Project Path="samples/Durable/Workflow/ConsoleApps/01_SequentialWorkflow/01_SequentialWorkflow.csproj" />
+    <Project Path="samples/Durable/Workflow/ConsoleApps/02_ConcurrentWorkflow/02_ConcurrentWorkflow.csproj" />
+    <Project Path="samples/Durable/Workflow/ConsoleApps/03_ConditionalEdges/03_ConditionalEdges.csproj" />
+  </Folder>
   <Folder Name="/Samples/GettingStarted/">
     <File Path="samples/GettingStarted/README.md" />
   </Folder>

dotnet/samples/Durable/Workflow/ConsoleApps/01_SequentialWorkflow/01_SequentialWorkflow.csproj

@@ -0,0 +1,29 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFrameworks>net10.0</TargetFrameworks>
+    <OutputType>Exe</OutputType>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <AssemblyName>SequentialWorkflow</AssemblyName>
+    <RootNamespace>SequentialWorkflow</RootNamespace>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Azure.Identity" />
+    <PackageReference Include="Microsoft.DurableTask.Client.AzureManaged" />
+    <PackageReference Include="Microsoft.DurableTask.Worker.AzureManaged" />
+    <PackageReference Include="Microsoft.Extensions.Hosting" />
+  </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" />
+    <ProjectReference Include="..\..\..\..\..\src\Microsoft.Agents.AI.OpenAI\Microsoft.Agents.AI.OpenAI.csproj" />
+  </ItemGroup>
+</Project>

dotnet/samples/Durable/Workflow/ConsoleApps/01_SequentialWorkflow/OrderCancelExecutors.cs

@@ -0,0 +1,107 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using Microsoft.Agents.AI.Workflows;
+
+namespace SequentialWorkflow;
+
+/// <summary>
+/// Looks up an order by its ID and return an Order object.
+/// </summary>
+internal sealed class OrderLookup() : Executor<string, Order>("OrderLookup")
+{
+    public override async ValueTask<Order> HandleAsync(
+        string message,
+        IWorkflowContext context,
+        CancellationToken cancellationToken = default)
+    {
+        Console.WriteLine();
+        Console.ForegroundColor = ConsoleColor.Magenta;
+        Console.WriteLine("┌─────────────────────────────────────────────────────────────────┐");
+        Console.WriteLine($"│ [Activity] OrderLookup: Starting lookup for order '{message}'");
+        Console.ResetColor();
+
+        // Simulate database lookup with delay
+        await Task.Delay(TimeSpan.FromMicroseconds(100), cancellationToken);
+
+        Order order = new(
+            Id: message,
+            OrderDate: DateTime.UtcNow.AddDays(-1),
+            IsCancelled: false,
+            Customer: new Customer(Name: "Jerry", Email: "jerry@example.com"));
+
+        Console.ForegroundColor = ConsoleColor.Magenta;
+        Console.WriteLine($"│ [Activity] OrderLookup: Found order '{message}' for customer '{order.Customer.Name}'");
+        Console.WriteLine("└─────────────────────────────────────────────────────────────────┘");
+        Console.ResetColor();
+
+        return order;
+    }
+}
+
+/// <summary>
+/// Cancels an order.
+/// </summary>
+internal sealed class OrderCancel() : Executor<Order, Order>("OrderCancel")
+{
+    public override async ValueTask<Order> HandleAsync(
+        Order message,
+        IWorkflowContext context,
+        CancellationToken cancellationToken = default)
+    {
+        // Log that this activity is executing (not replaying)
+        Console.WriteLine();
+        Console.ForegroundColor = ConsoleColor.Yellow;
+        Console.WriteLine("┌─────────────────────────────────────────────────────────────────┐");
+        Console.WriteLine($"│ [Activity] OrderCancel: Starting cancellation for order '{message.Id}'");
+        Console.ResetColor();
+
+        // Simulate a slow cancellation process (e.g., calling external payment system)
+        for (int i = 1; i <= 3; i++)
+        {
+            await Task.Delay(TimeSpan.FromMilliseconds(100), cancellationToken);
+            Console.ForegroundColor = ConsoleColor.DarkYellow;
+            Console.WriteLine("│ [Activity] OrderCancel: Processing...");
+            Console.ResetColor();
+        }
+
+        Order cancelledOrder = message with { IsCancelled = true };
+
+        Console.ForegroundColor = ConsoleColor.Yellow;
+        Console.WriteLine($"│ [Activity] OrderCancel: ✓ Order '{cancelledOrder.Id}' has been cancelled");
+        Console.WriteLine("└─────────────────────────────────────────────────────────────────┘");
+        Console.ResetColor();
+
+        return cancelledOrder;
+    }
+}
+
+/// <summary>
+/// Sends a cancellation confirmation email to the customer.
+/// </summary>
+internal sealed class SendEmail() : Executor<Order, string>("SendEmail")
+{
+    public override ValueTask<string> HandleAsync(
+        Order message,
+        IWorkflowContext context,
+        CancellationToken cancellationToken = default)
+    {
+        Console.WriteLine();
+        Console.ForegroundColor = ConsoleColor.Cyan;
+        Console.WriteLine("┌─────────────────────────────────────────────────────────────────┐");
+        Console.WriteLine($"│ [Activity] SendEmail: Sending email to '{message.Customer.Email}'...");
+        Console.ResetColor();
+
+        string result = $"Cancellation email sent for order {message.Id} to {message.Customer.Email}.";
+
+        Console.ForegroundColor = ConsoleColor.Cyan;
+        Console.WriteLine("│ [Activity] SendEmail: ✓ Email sent successfully!");
+        Console.WriteLine("└─────────────────────────────────────────────────────────────────┘");
+        Console.ResetColor();
+
+        return ValueTask.FromResult(result);
+    }
+}
+
+internal sealed record Order(string Id, DateTime OrderDate, bool IsCancelled, Customer Customer);
+
+internal sealed record Customer(string Name, string Email);

dotnet/samples/Durable/Workflow/ConsoleApps/01_SequentialWorkflow/Program.cs

@@ -0,0 +1,91 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+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 SequentialWorkflow;
+
+// Get DTS connection string from environment variable
+string dtsConnectionString = Environment.GetEnvironmentVariable("DURABLE_TASK_SCHEDULER_CONNECTION_STRING")
+    ?? "Endpoint=http://localhost:8080;TaskHub=default;Authentication=None";
+
+// Define executors for the workflow
+OrderLookup orderLookup = new();
+OrderCancel orderCancel = new();
+SendEmail sendEmail = new();
+
+// Build the CancelOrder workflow: OrderLookup -> OrderCancel -> SendEmail
+Workflow cancelOrder = new WorkflowBuilder(orderLookup)
+    .WithName("CancelOrder")
+    .WithDescription("Cancel an order and notify the customer")
+    .AddEdge(orderLookup, orderCancel)
+    .AddEdge(orderCancel, sendEmail)
+    .Build();
+
+IHost host = Host.CreateDefaultBuilder(args)
+.ConfigureLogging(logging => logging.SetMinimumLevel(LogLevel.Warning))
+.ConfigureServices(services =>
+{
+    services.ConfigureDurableWorkflows(
+        workflowOptions => workflowOptions.AddWorkflow(cancelOrder),
+        workerBuilder: builder => builder.UseDurableTaskScheduler(dtsConnectionString),
+        clientBuilder: builder => builder.UseDurableTaskScheduler(dtsConnectionString));
+})
+.Build();
+
+await host.StartAsync();
+
+IWorkflowClient workflowClient = host.Services.GetRequiredService<IWorkflowClient>();
+
+Console.WriteLine("Durable Workflow Sample");
+Console.WriteLine("Workflow: OrderLookup -> OrderCancel -> SendEmail");
+Console.WriteLine();
+Console.WriteLine("Enter an order ID (or 'exit'):");
+
+while (true)
+{
+    Console.Write("> ");
+    string? input = Console.ReadLine();
+    if (string.IsNullOrWhiteSpace(input) || input.Equals("exit", StringComparison.OrdinalIgnoreCase))
+    {
+        break;
+    }
+
+    try
+    {
+        await StartNewWorkflowAsync(input, cancelOrder, workflowClient);
+    }
+    catch (Exception ex)
+    {
+        Console.WriteLine($"Error: {ex.Message}");
+    }
+
+    Console.WriteLine();
+}
+
+await host.StopAsync();
+
+// Start a new workflow using IWorkflowClient (no DurableTaskClient needed)
+static async Task StartNewWorkflowAsync(string orderId, Workflow workflow, IWorkflowClient client)
+{
+    Console.WriteLine($"Starting workflow for order '{orderId}'...");
+
+    // RunAsync returns IWorkflowRun, cast to IAwaitableWorkflowRun for completion waiting
+    IAwaitableWorkflowRun run = (IAwaitableWorkflowRun)await client.RunAsync(workflow, orderId);
+    Console.WriteLine($"Run ID: {run.RunId}");
+
+    try
+    {
+        Console.WriteLine("Waiting for workflow to complete...");
+        string? result = await run.WaitForCompletionAsync<string>();
+        Console.WriteLine($"Workflow completed. {result}");
+    }
+    catch (InvalidOperationException ex)
+    {
+        Console.WriteLine($"Failed: {ex.Message}");
+    }
+}

dotnet/samples/Durable/Workflow/ConsoleApps/01_SequentialWorkflow/README.md

@@ -0,0 +1,83 @@
+# Sequential Workflow Sample
+
+This sample demonstrates how to run a sequential workflow as a durable orchestration from a console application using the Durable Task Framework. It showcases the **durability** aspect - if the process crashes mid-execution, the workflow automatically resumes without re-executing completed activities.
+
+## Key Concepts Demonstrated
+
+- Building a sequential workflow with the `WorkflowBuilder` API
+- Using `ConfigureDurableWorkflows` to register workflows with dependency injection
+- Running workflows with `IWorkflowClient`
+- **Durability**: Automatic resume of interrupted workflows
+- **Activity caching**: Completed activities are not re-executed on replay
+
+## Overview
+
+The sample implements an order cancellation workflow with three executors:
+
+```
+OrderLookup --> OrderCancel --> SendEmail
+```
+
+| Executor | Description |
+|----------|-------------|
+| OrderLookup | Looks up an order by ID |
+| OrderCancel | Marks the order as cancelled |
+| SendEmail | Sends a cancellation confirmation email |
+
+## Durability Demonstration
+
+The key feature of Durable Task Framework is **durability**:
+
+- **Activity results are persisted**: When an activity completes, its result is saved
+- **Orchestrations replay**: On restart, the orchestration replays from the beginning
+- **Completed activities skip execution**: The framework uses cached results
+- **Automatic resume**: The worker automatically picks up pending work on startup
+
+### Try It Yourself
+
+> **Tip:** To give yourself more time to stop the application during `OrderCancel`, consider increasing the loop iteration count or `Task.Delay` duration in the `OrderCancel` executor in `OrderCancelExecutors.cs`.
+
+1. Start the application and enter an order ID (e.g., `12345`)
+2. Wait for `OrderLookup` to complete, then stop the app (Ctrl+C) during `OrderCancel`
+3. Restart the application
+4. Observe:
+   - `OrderLookup` is **NOT** re-executed (result was cached)
+   - `OrderCancel` **restarts** (it didn't complete before the interruption)
+   - `SendEmail` runs after `OrderCancel` completes
+
+## Environment Setup
+
+See the [README.md](../README.md) file in the parent directory for information on configuring the environment, including how to install and run the Durable Task Scheduler.
+
+## Running the Sample
+
+```bash
+cd dotnet/samples/Durable/Workflow/ConsoleApps/01_SequentialWorkflow
+dotnet run --framework net10.0
+```
+
+### Sample Output
+
+```text
+Durable Workflow Sample
+Workflow: OrderLookup -> OrderCancel -> SendEmail
+
+Enter an order ID (or 'exit'):
+> 12345
+Starting workflow for order: 12345
+Run ID: abc123...
+
+[OrderLookup] Looking up order '12345'...
+[OrderLookup] Found order for customer 'Jerry'
+
+[OrderCancel] Cancelling order '12345'...
+[OrderCancel] Order cancelled successfully
+
+[SendEmail] Sending email to 'jerry@example.com'...
+[SendEmail] Email sent successfully
+
+Workflow completed!
+
+> exit
+```
+

dotnet/samples/Durable/Workflow/ConsoleApps/02_ConcurrentWorkflow/02_ConcurrentWorkflow.csproj

@@ -0,0 +1,30 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFrameworks>net10.0</TargetFrameworks>
+    <OutputType>Exe</OutputType>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <AssemblyName>WorkflowConcurrency</AssemblyName>
+    <RootNamespace>WorkflowConcurrency</RootNamespace>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Azure.Identity" />
+    <PackageReference Include="Microsoft.DurableTask.Client.AzureManaged" />
+    <PackageReference Include="Microsoft.DurableTask.Worker.AzureManaged" />
+    <PackageReference Include="Microsoft.Extensions.Hosting" />
+    <PackageReference Include="Azure.AI.OpenAI" />
+  </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" />
+    <ProjectReference Include="..\..\..\..\..\src\Microsoft.Agents.AI.OpenAI\Microsoft.Agents.AI.OpenAI.csproj" />
+  </ItemGroup>
+</Project>