Adding support for events & shared state in durable workflows.

2026-06-16 21:04:09 +08:00 · 2026-02-17 14:41:11 -08:00
parent b62b1f2191
commit 8ffe7e6092
32 changed files with 2128 additions and 96 deletions
@@ -0,0 +1,29 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFrameworks>net10.0</TargetFrameworks>
+    <OutputType>Exe</OutputType>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <AssemblyName>WorkflowEvents</AssemblyName>
+    <RootNamespace>WorkflowEvents</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>
@@ -0,0 +1,122 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using Microsoft.Agents.AI.Workflows;
+
+namespace WorkflowEvents;
+
+// ═══════════════════════════════════════════════════════════════════════════════
+// Custom event types - callers observe these via WatchStreamAsync
+// ═══════════════════════════════════════════════════════════════════════════════
+
+internal sealed class OrderLookupStartedEvent(string orderId) : WorkflowEvent(orderId)
+{
+    public string OrderId { get; } = orderId;
+}
+
+internal sealed class OrderFoundEvent(string customerName) : WorkflowEvent(customerName)
+{
+    public string CustomerName { get; } = customerName;
+}
+
+internal sealed class CancellationProgressEvent(int percentComplete, string status) : WorkflowEvent(status)
+{
+    public int PercentComplete { get; } = percentComplete;
+    public string Status { get; } = status;
+}
+
+internal sealed class OrderCancelledEvent() : WorkflowEvent("Order cancelled");
+
+internal sealed class EmailSentEvent(string email) : WorkflowEvent(email)
+{
+    public string Email { get; } = email;
+}
+
+// ═══════════════════════════════════════════════════════════════════════════════
+// Domain models
+// ═══════════════════════════════════════════════════════════════════════════════
+
+internal sealed record Order(string Id, DateTime OrderDate, bool IsCancelled, string? CancelReason, Customer Customer);
+
+internal sealed record Customer(string Name, string Email);
+
+// ═══════════════════════════════════════════════════════════════════════════════
+// Executors - emit events via IWorkflowContext.AddEventAsync
+// ═══════════════════════════════════════════════════════════════════════════════
+
+/// <summary>
+/// Looks up an order by ID, emitting progress events.
+/// </summary>
+internal sealed class OrderLookup() : Executor<string, Order>("OrderLookup")
+{
+    public override async ValueTask<Order> HandleAsync(
+        string message,
+        IWorkflowContext context,
+        CancellationToken cancellationToken = default)
+    {
+        await context.AddEventAsync(new OrderLookupStartedEvent(message), cancellationToken);
+
+        // Simulate database lookup
+        await Task.Delay(TimeSpan.FromSeconds(1), cancellationToken);
+
+        Order order = new(
+            Id: message,
+            OrderDate: DateTime.UtcNow.AddDays(-1),
+            IsCancelled: false,
+            CancelReason: "Customer requested cancellation",
+            Customer: new Customer(Name: "Jerry", Email: "jerry@example.com"));
+
+        await context.AddEventAsync(new OrderFoundEvent(order.Customer.Name), cancellationToken);
+
+        return order;
+    }
+}
+
+/// <summary>
+/// Cancels an order, emitting progress events during the multi-step process.
+/// </summary>
+internal sealed class OrderCancel() : Executor<Order, Order>("OrderCancel")
+{
+    public override async ValueTask<Order> HandleAsync(
+        Order message,
+        IWorkflowContext context,
+        CancellationToken cancellationToken = default)
+    {
+        await context.AddEventAsync(new CancellationProgressEvent(0, "Starting cancellation"), cancellationToken);
+
+        // Simulate a multi-step cancellation process
+        await Task.Delay(TimeSpan.FromMilliseconds(500), cancellationToken);
+        await context.AddEventAsync(new CancellationProgressEvent(33, "Contacting payment provider"), cancellationToken);
+
+        await Task.Delay(TimeSpan.FromMilliseconds(500), cancellationToken);
+        await context.AddEventAsync(new CancellationProgressEvent(66, "Processing refund"), cancellationToken);
+
+        await Task.Delay(TimeSpan.FromMilliseconds(500), cancellationToken);
+
+        Order cancelledOrder = message with { IsCancelled = true };
+        await context.AddEventAsync(new CancellationProgressEvent(100, "Complete"), cancellationToken);
+        await context.AddEventAsync(new OrderCancelledEvent(), cancellationToken);
+
+        return cancelledOrder;
+    }
+}
+
+/// <summary>
+/// Sends a cancellation confirmation email, emitting an event on completion.
+/// </summary>
+internal sealed class SendEmail() : Executor<Order, string>("SendEmail")
+{
+    public override async ValueTask<string> HandleAsync(
+        Order message,
+        IWorkflowContext context,
+        CancellationToken cancellationToken = default)
+    {
+        // Simulate sending email
+        await Task.Delay(TimeSpan.FromMilliseconds(500), cancellationToken);
+
+        string result = $"Cancellation email sent for order {message.Id} to {message.Customer.Email}.";
+
+        await context.AddEventAsync(new EmailSentEvent(message.Customer.Email), cancellationToken);
+
+        return result;
+    }
+}
@@ -0,0 +1,138 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+// ═══════════════════════════════════════════════════════════════════════════════
+// SAMPLE: Workflow Events and Streaming
+// ═══════════════════════════════════════════════════════════════════════════════
+//
+// This sample demonstrates how to use IWorkflowContext event methods in executors
+// and stream events from the caller side:
+//
+// 1. AddEventAsync     - Emit custom events that callers can observe in real-time
+// 2. StreamAsync       - Start a workflow and obtain a streaming handle
+// 3. WatchStreamAsync  - Observe events as they occur (custom, framework, and terminal)
+//
+// The sample uses IWorkflowClient.StreamAsync to start a workflow and
+// WatchStreamAsync to observe events as they occur in real-time.
+//
+// Workflow: OrderLookup -> OrderCancel -> SendEmail
+// ═══════════════════════════════════════════════════════════════════════════════
+
+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 WorkflowEvents;
+
+// 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 and build workflow
+OrderLookup orderLookup = new();
+OrderCancel orderCancel = new();
+SendEmail sendEmail = new();
+
+Workflow cancelOrder = new WorkflowBuilder(orderLookup)
+    .WithName("CancelOrder")
+    .WithDescription("Cancel an order and notify the customer")
+    .AddEdge(orderLookup, orderCancel)
+    .AddEdge(orderCancel, sendEmail)
+    .Build();
+
+// Configure host with durable workflow support
+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("Workflow Events Demo - Enter order ID (or 'exit'):");
+
+while (true)
+{
+    Console.Write("> ");
+    string? input = Console.ReadLine();
+    if (string.IsNullOrWhiteSpace(input) || input.Equals("exit", StringComparison.OrdinalIgnoreCase))
+    {
+        break;
+    }
+
+    try
+    {
+        await RunWorkflowWithStreamingAsync(input, cancelOrder, workflowClient);
+    }
+    catch (Exception ex)
+    {
+        Console.WriteLine($"Error: {ex.Message}");
+    }
+
+    Console.WriteLine();
+}
+
+await host.StopAsync();
+
+// Runs a workflow and streams events as they occur
+static async Task RunWorkflowWithStreamingAsync(string orderId, Workflow workflow, IWorkflowClient client)
+{
+    // StreamAsync starts the workflow and returns a streaming handle for observing events
+    IStreamingWorkflowRun run = await client.StreamAsync(workflow, orderId);
+    Console.WriteLine($"Started run: {run.RunId}");
+
+    // WatchStreamAsync yields events as they're emitted by executors
+    await foreach (WorkflowEvent evt in run.WatchStreamAsync())
+    {
+        Console.WriteLine($"  New event received at {DateTime.Now:HH:mm:ss.ffff} ({evt.GetType().Name})");
+
+        switch (evt)
+        {
+            // Custom domain events (emitted via AddEventAsync)
+            case OrderLookupStartedEvent e:
+                WriteColored($"    [Lookup] Looking up order {e.OrderId}", ConsoleColor.Cyan);
+                break;
+            case OrderFoundEvent e:
+                WriteColored($"    [Lookup] Found: {e.CustomerName}", ConsoleColor.Cyan);
+                break;
+            case CancellationProgressEvent e:
+                WriteColored($"    [Cancel] {e.PercentComplete}% - {e.Status}", ConsoleColor.Yellow);
+                break;
+            case OrderCancelledEvent:
+                WriteColored("    [Cancel] Done", ConsoleColor.Yellow);
+                break;
+            case EmailSentEvent e:
+                WriteColored($"    [Email] Sent to {e.Email}", ConsoleColor.Magenta);
+                break;
+
+            case WorkflowOutputEvent e:
+                WriteColored($"    [Output] {e.SourceId}", ConsoleColor.DarkGray);
+                break;
+
+            // Workflow completion
+            case DurableWorkflowCompletedEvent e:
+                WriteColored($"  Completed: {e.Result}", ConsoleColor.Green);
+                break;
+            case DurableWorkflowFailedEvent e:
+                WriteColored($"  Failed: {e.ErrorMessage}", ConsoleColor.Red);
+                break;
+        }
+    }
+}
+
+static void WriteColored(string message, ConsoleColor color)
+{
+    Console.ForegroundColor = color;
+    Console.WriteLine(message);
+    Console.ResetColor();
+}
@@ -0,0 +1,127 @@
+# Workflow Events Sample
+
+This sample demonstrates how to use workflow events and streaming in durable workflows.
+
+## What it demonstrates
+
+1. **Custom Events** (`AddEventAsync`) — Executors emit domain-specific events during execution
+2. **Event Streaming** (`StreamAsync` / `WatchStreamAsync`) — Callers observe events in real-time as the workflow progresses
+3. **Framework Events** — Automatic `ExecutorInvokedEvent`, `ExecutorCompletedEvent`, and `WorkflowOutputEvent` events emitted by the framework
+
+## Emitting Custom Events
+
+Executors can emit custom domain events during execution using the `IWorkflowContext` instance passed to `HandleAsync`. These events are streamed to callers in real-time via `WatchStreamAsync`.
+
+### Defining a custom event
+
+Create a class that inherits from `WorkflowEvent`. Pass any data payload to the base constructor:
+
+```csharp
+public class CancellationProgressEvent(int percentComplete, string status) : WorkflowEvent(status)
+{
+    public int PercentComplete { get; } = percentComplete;
+    public string Status { get; } = status;
+}
+```
+
+### Emitting the event from an executor
+
+Call `AddEventAsync` on the `IWorkflowContext` inside your executor's `HandleAsync` method:
+
+```csharp
+public override async ValueTask<Order> HandleAsync(
+    Order message,
+    IWorkflowContext context,
+    CancellationToken cancellationToken = default)
+{
+    await context.AddEventAsync(new CancellationProgressEvent(33, "Processing refund"), cancellationToken);
+    // ... rest of the executor logic
+}
+```
+
+### Observing events from the caller
+
+Use `StreamAsync` to start the workflow and `WatchStreamAsync` to observe events. Pattern match on your custom event types:
+
+```csharp
+IStreamingWorkflowRun run = await workflowClient.StreamAsync(workflow, input);
+
+await foreach (WorkflowEvent evt in run.WatchStreamAsync())
+{
+    switch (evt)
+    {
+        case CancellationProgressEvent e:
+            Console.WriteLine($"{e.PercentComplete}% - {e.Status}");
+            break;
+    }
+}
+```
+
+## Workflow Structure
+
+```
+OrderLookup → OrderCancel → SendEmail
+```
+
+Each executor emits custom events during execution:
+- `OrderLookup` emits `OrderLookupStartedEvent` and `OrderFoundEvent`
+- `OrderCancel` emits `CancellationProgressEvent` (with percentage) and `OrderCancelledEvent`
+- `SendEmail` emits `EmailSentEvent`
+
+## Prerequisites
+
+- [Durable Task Scheduler](https://learn.microsoft.com/azure/azure-functions/durable/durable-task-scheduler) running locally or in Azure
+- Set the `DURABLE_TASK_SCHEDULER_CONNECTION_STRING` environment variable (defaults to local emulator)
+
+## Environment Setup
+
+See the [README.md](../../README.md) file in the parent directory for more information on how to configure the environment, including how to install and run common sample dependencies.
+
+## Running the sample
+
+```bash
+dotnet run
+```
+
+Enter an order ID at the prompt to start a workflow and watch events stream in real-time:
+
+```text
+> order-42
+Started run: b6ba4d19...
+  New event received at 13:27:41.4956 (ExecutorInvokedEvent)
+  New event received at 13:27:41.5019 (OrderLookupStartedEvent)
+    [Lookup] Looking up order order-42
+  New event received at 13:27:41.5025 (OrderFoundEvent)
+    [Lookup] Found: Jerry
+  New event received at 13:27:41.5026 (ExecutorCompletedEvent)
+  New event received at 13:27:41.5026 (WorkflowOutputEvent)
+    [Output] OrderLookup
+  New event received at 13:27:43.0772 (ExecutorInvokedEvent)
+  New event received at 13:27:43.0773 (CancellationProgressEvent)
+    [Cancel] 0% - Starting cancellation
+  New event received at 13:27:43.0775 (CancellationProgressEvent)
+    [Cancel] 33% - Contacting payment provider
+  New event received at 13:27:43.0776 (CancellationProgressEvent)
+    [Cancel] 66% - Processing refund
+  New event received at 13:27:43.0777 (CancellationProgressEvent)
+    [Cancel] 100% - Complete
+  New event received at 13:27:43.0779 (OrderCancelledEvent)
+    [Cancel] Done
+  New event received at 13:27:43.0780 (ExecutorCompletedEvent)
+  New event received at 13:27:43.0780 (WorkflowOutputEvent)
+    [Output] OrderCancel
+  New event received at 13:27:43.6610 (ExecutorInvokedEvent)
+  New event received at 13:27:43.6611 (EmailSentEvent)
+    [Email] Sent to jerry@example.com
+  New event received at 13:27:43.6613 (ExecutorCompletedEvent)
+  New event received at 13:27:43.6613 (WorkflowOutputEvent)
+    [Output] SendEmail
+  New event received at 13:27:43.6619 (DurableWorkflowCompletedEvent)
+  Completed: Cancellation email sent for order order-42 to jerry@example.com.
+```
+
+### Viewing Workflows in the DTS Dashboard
+
+After running a workflow, you can navigate to the Durable Task Scheduler (DTS) dashboard to inspect the workflow execution and events.
+
+If you are using the DTS emulator, the dashboard is available at `http://localhost:8082`.
@@ -0,0 +1,29 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFrameworks>net10.0</TargetFrameworks>
+    <OutputType>Exe</OutputType>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <AssemblyName>WorkflowSharedState</AssemblyName>
+    <RootNamespace>WorkflowSharedState</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>
@@ -0,0 +1,185 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using Microsoft.Agents.AI.Workflows;
+
+namespace WorkflowSharedState;
+
+// ═══════════════════════════════════════════════════════════════════════════════
+// Domain models
+// ═══════════════════════════════════════════════════════════════════════════════
+
+/// <summary>
+/// The primary order data passed through the pipeline via return values.
+/// </summary>
+internal sealed record OrderDetails(string OrderId, string CustomerName, decimal Amount, DateTime OrderDate);
+
+/// <summary>
+/// Cross-cutting audit trail accumulated in shared state across executors.
+/// Each executor appends its step name and timestamp. This data does not flow
+/// through return values — it lives only in shared state.
+/// </summary>
+internal sealed record AuditEntry(string Step, string Timestamp, string Detail);
+
+// ═══════════════════════════════════════════════════════════════════════════════
+// Executors
+// ═══════════════════════════════════════════════════════════════════════════════
+
+/// <summary>
+/// Validates the order and writes the initial audit entry and tax rate to shared state.
+/// The order details are returned as the executor output (normal message flow),
+/// while the audit trail and tax rate are stored in shared state (side-channel).
+/// If the order ID starts with "INVALID", the executor halts the workflow early
+/// using <see cref="IWorkflowContext.RequestHaltAsync"/>.
+/// </summary>
+internal sealed class ValidateOrder() : Executor<string, OrderDetails>("ValidateOrder")
+{
+    public override async ValueTask<OrderDetails> HandleAsync(
+        string message,
+        IWorkflowContext context,
+        CancellationToken cancellationToken = default)
+    {
+        await Task.Delay(TimeSpan.FromMilliseconds(200), cancellationToken);
+
+        // Halt the workflow early if the order ID is invalid.
+        // No downstream executors will run after this.
+        if (message.StartsWith("INVALID", StringComparison.OrdinalIgnoreCase))
+        {
+            await context.YieldOutputAsync($"Order '{message}' failed validation. Halting workflow.", cancellationToken);
+            await context.RequestHaltAsync();
+            return new OrderDetails(message, "Unknown", 0, DateTime.UtcNow);
+        }
+
+        OrderDetails details = new(message, "Jerry", 249.99m, DateTime.UtcNow);
+
+        // Store the tax rate in shared state — downstream ProcessPayment reads it
+        // without needing it in the message chain.
+        await context.QueueStateUpdateAsync("taxRate", 0.085m, cancellationToken: cancellationToken);
+        Console.WriteLine("    Wrote to shared state: taxRate = 8.5%");
+
+        // Start the audit trail in shared state
+        AuditEntry audit = new("ValidateOrder", DateTime.UtcNow.ToString("o"), $"Validated order {message}");
+        await context.QueueStateUpdateAsync("audit:validate", audit, cancellationToken: cancellationToken);
+        Console.WriteLine("    Wrote to shared state: audit:validate");
+
+        await context.YieldOutputAsync($"Order '{message}' validated. Customer: {details.CustomerName}, Amount: {details.Amount:C}", cancellationToken);
+
+        return details;
+    }
+}
+
+/// <summary>
+/// Enriches the order with shipping information.
+/// Reads the audit trail from shared state and appends its own entry.
+/// Uses ReadOrInitStateAsync to lazily initialize a shipping tier.
+/// Demonstrates custom scopes by writing shipping details under the "shipping" scope.
+/// </summary>
+internal sealed class EnrichOrder() : Executor<OrderDetails, OrderDetails>("EnrichOrder")
+{
+    public override async ValueTask<OrderDetails> HandleAsync(
+        OrderDetails message,
+        IWorkflowContext context,
+        CancellationToken cancellationToken = default)
+    {
+        await Task.Delay(TimeSpan.FromMilliseconds(200), cancellationToken);
+
+        // Use ReadOrInitStateAsync — only initializes if no value exists yet
+        string shippingTier = await context.ReadOrInitStateAsync(
+            "shippingTier",
+            () => "Express",
+            cancellationToken: cancellationToken);
+        Console.WriteLine($"    Read from shared state: shippingTier = {shippingTier}");
+
+        // Write shipping details under a custom "shipping" scope.
+        // Scoped keys are isolated from the default namespace, so "carrier" here
+        // won't collide with a "carrier" key in the default scope.
+        await context.QueueStateUpdateAsync("carrier", "Contoso Express", scopeName: "shipping", cancellationToken: cancellationToken);
+        await context.QueueStateUpdateAsync("estimatedDays", 2, scopeName: "shipping", cancellationToken: cancellationToken);
+        Console.WriteLine("    Wrote to shared state: shipping:carrier = Contoso Express");
+        Console.WriteLine("    Wrote to shared state: shipping:estimatedDays = 2");
+
+        // Verify we can read the audit entry from the previous step
+        AuditEntry? previousAudit = await context.ReadStateAsync<AuditEntry>("audit:validate", cancellationToken: cancellationToken);
+        string auditStatus = previousAudit is not null ? $"(previous step: {previousAudit.Step})" : "(no prior audit)";
+        Console.WriteLine($"    Read from shared state: audit:validate {auditStatus}");
+
+        // Append our own audit entry
+        AuditEntry audit = new("EnrichOrder", DateTime.UtcNow.ToString("o"), $"Enriched with {shippingTier} shipping {auditStatus}");
+        await context.QueueStateUpdateAsync("audit:enrich", audit, cancellationToken: cancellationToken);
+        Console.WriteLine("    Wrote to shared state: audit:enrich");
+
+        await context.YieldOutputAsync($"Order enriched. Shipping: {shippingTier} {auditStatus}", cancellationToken);
+
+        return message;
+    }
+}
+
+/// <summary>
+/// Processes payment using the tax rate from shared state (written by ValidateOrder).
+/// The tax rate is side-channel data — it doesn't flow through return values.
+/// </summary>
+internal sealed class ProcessPayment() : Executor<OrderDetails, string>("ProcessPayment")
+{
+    public override async ValueTask<string> HandleAsync(
+        OrderDetails message,
+        IWorkflowContext context,
+        CancellationToken cancellationToken = default)
+    {
+        await Task.Delay(TimeSpan.FromMilliseconds(300), cancellationToken);
+
+        // Read tax rate written by ValidateOrder — not available in the message chain
+        decimal taxRate = await context.ReadOrInitStateAsync("taxRate", () => 0.0m, cancellationToken: cancellationToken);
+        Console.WriteLine($"    Read from shared state: taxRate = {taxRate:P1}");
+
+        decimal tax = message.Amount * taxRate;
+        decimal total = message.Amount + tax;
+        string paymentRef = $"PAY-{Guid.NewGuid():N}"[..16];
+
+        // Append audit entry
+        AuditEntry audit = new("ProcessPayment", DateTime.UtcNow.ToString("o"), $"Charged {total:C} (tax: {tax:C})");
+        await context.QueueStateUpdateAsync("audit:payment", audit, cancellationToken: cancellationToken);
+        Console.WriteLine("    Wrote to shared state: audit:payment");
+
+        await context.YieldOutputAsync($"Payment processed. Total: {total:C} (tax: {tax:C}). Ref: {paymentRef}", cancellationToken);
+
+        return paymentRef;
+    }
+}
+
+/// <summary>
+/// Generates the final invoice by reading the full audit trail from shared state.
+/// Demonstrates reading multiple state entries written by different executors
+/// and clearing a scope with <see cref="IWorkflowContext.QueueClearScopeAsync(string?, CancellationToken)"/>.
+/// </summary>
+internal sealed class GenerateInvoice() : Executor<string, string>("GenerateInvoice")
+{
+    public override async ValueTask<string> HandleAsync(
+        string message,
+        IWorkflowContext context,
+        CancellationToken cancellationToken = default)
+    {
+        await Task.Delay(TimeSpan.FromMilliseconds(100), cancellationToken);
+
+        // Read the full audit trail from shared state — each step wrote its own entry
+        AuditEntry? validateAudit = await context.ReadStateAsync<AuditEntry>("audit:validate", cancellationToken: cancellationToken);
+        AuditEntry? enrichAudit = await context.ReadStateAsync<AuditEntry>("audit:enrich", cancellationToken: cancellationToken);
+        AuditEntry? paymentAudit = await context.ReadStateAsync<AuditEntry>("audit:payment", cancellationToken: cancellationToken);
+        int auditCount = new[] { validateAudit, enrichAudit, paymentAudit }.Count(a => a is not null);
+        Console.WriteLine($"    Read from shared state: {auditCount} audit entries");
+
+        // Clear the "shipping" scope — no longer needed after invoice generation.
+        // This removes all keys under that scope (carrier, estimatedDays).
+        await context.QueueClearScopeAsync("shipping", cancellationToken);
+        Console.WriteLine("    Cleared shared state scope: shipping");
+
+        string auditSummary = string.Join(" → ", new[]
+        {
+            validateAudit?.Step, enrichAudit?.Step, paymentAudit?.Step
+        }.Where(s => s is not null));
+
+        string invoice = $"Invoice complete. Payment: {message}. Audit trail: [{auditSummary}]";
+
+        await context.YieldOutputAsync(invoice, cancellationToken);
+
+        return invoice;
+    }
+}
@@ -0,0 +1,117 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+// ═══════════════════════════════════════════════════════════════════════════════
+// SAMPLE: Shared State During Workflow Execution
+// ═══════════════════════════════════════════════════════════════════════════════
+//
+// This sample demonstrates how executors in a durable workflow can share state
+// via IWorkflowContext. State is persisted across supersteps and survives
+// process restarts because the orchestration passes it to each activity.
+//
+// Key concepts:
+//   1. QueueStateUpdateAsync  - Write a value to shared state
+//   2. ReadStateAsync         - Read a value written by a previous executor
+//   3. ReadOrInitStateAsync   - Read or lazily initialize a state value
+//   4. QueueClearScopeAsync   - Clear all entries under a scope
+//   5. RequestHaltAsync       - Stop the workflow early (e.g., validation failure)
+//
+// Workflow: ValidateOrder -> EnrichOrder -> ProcessPayment -> GenerateInvoice
+//
+// Return values carry primary business data through the pipeline (OrderDetails,
+// payment ref). Shared state carries side-channel data that doesn't belong in
+// the message chain: a tax rate (set by ValidateOrder, read by ProcessPayment)
+// and an audit trail (each executor appends its own entry).
+// ═══════════════════════════════════════════════════════════════════════════════
+
+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 WorkflowSharedState;
+
+// 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
+ValidateOrder validateOrder = new();
+EnrichOrder enrichOrder = new();
+ProcessPayment processPayment = new();
+GenerateInvoice generateInvoice = new();
+
+// Build the workflow: ValidateOrder -> EnrichOrder -> ProcessPayment -> GenerateInvoice
+Workflow orderPipeline = new WorkflowBuilder(validateOrder)
+    .WithName("OrderPipeline")
+    .WithDescription("Order processing pipeline with shared state across executors")
+    .AddEdge(validateOrder, enrichOrder)
+    .AddEdge(enrichOrder, processPayment)
+    .AddEdge(processPayment, generateInvoice)
+    .Build();
+
+// Configure host with durable workflow support
+IHost host = Host.CreateDefaultBuilder(args)
+    .ConfigureLogging(logging => logging.SetMinimumLevel(LogLevel.Warning))
+    .ConfigureServices(services =>
+    {
+        services.ConfigureDurableWorkflows(
+            workflowOptions => workflowOptions.AddWorkflow(orderPipeline),
+            workerBuilder: builder => builder.UseDurableTaskScheduler(dtsConnectionString),
+            clientBuilder: builder => builder.UseDurableTaskScheduler(dtsConnectionString));
+    })
+    .Build();
+
+await host.StartAsync();
+
+IWorkflowClient workflowClient = host.Services.GetRequiredService<IWorkflowClient>();
+
+Console.WriteLine("Shared State Workflow Demo");
+Console.WriteLine("Workflow: ValidateOrder -> EnrichOrder -> ProcessPayment -> GenerateInvoice");
+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
+    {
+        // Start the workflow and stream events to see shared state in action
+        IStreamingWorkflowRun run = await workflowClient.StreamAsync(orderPipeline, input);
+        Console.WriteLine($"Started run: {run.RunId}");
+
+        await foreach (WorkflowEvent evt in run.WatchStreamAsync())
+        {
+            switch (evt)
+            {
+                case WorkflowOutputEvent e:
+                    Console.WriteLine($"  [Output] {e.SourceId}: {e.Data}");
+                    break;
+
+                case DurableWorkflowCompletedEvent e:
+                    Console.WriteLine($"  Completed: {e.Result}");
+                    break;
+
+                case DurableWorkflowFailedEvent e:
+                    Console.WriteLine($"  Failed: {e.ErrorMessage}");
+                    break;
+            }
+        }
+    }
+    catch (Exception ex)
+    {
+        Console.WriteLine($"Error: {ex.Message}");
+    }
+
+    Console.WriteLine();
+}
+
+await host.StopAsync();
@@ -0,0 +1,68 @@
+# Shared State Workflow Sample
+
+This sample demonstrates how executors in a durable workflow can share state via `IWorkflowContext`. State written by one executor is accessible to all downstream executors, persisted across supersteps, and survives process restarts.
+
+## Key Concepts Demonstrated
+
+- Writing state with `QueueStateUpdateAsync` — executors store data for downstream executors
+- Reading state with `ReadStateAsync` — executors access data written by earlier executors
+- Lazy initialization with `ReadOrInitStateAsync` — initialize state only if not already present
+- Custom scopes with `scopeName` — partition state into isolated namespaces (e.g., `"shipping"`)
+- Clearing scopes with `QueueClearScopeAsync` — remove all entries under a scope when no longer needed
+- Early termination with `RequestHaltAsync` — halt the workflow when validation fails
+- State persistence across supersteps — the orchestration passes shared state to each activity
+- Event streaming with `IStreamingWorkflowRun` — observe executor progress in real time
+
+## Workflow
+
+**OrderPipeline**: `ValidateOrder` → `EnrichOrder` → `ProcessPayment` → `GenerateInvoice`
+
+Return values carry primary business data through the pipeline (`OrderDetails` → `OrderDetails` → payment ref → invoice string). Shared state carries side-channel data that doesn't belong in the message chain:
+
+| Executor | Returns (message flow) | Reads from State | Writes to State |
+|----------|----------------------|-----------------|-----------------|
+| **ValidateOrder** | `OrderDetails` | — | `taxRate`, `audit:validate` |
+| **EnrichOrder** | `OrderDetails` (pass-through) | `audit:validate` | `shippingTier`, `audit:enrich`, `shipping:carrier`, `shipping:estimatedDays` |
+| **ProcessPayment** | payment ref string | `taxRate` | `audit:payment` |
+| **GenerateInvoice** | invoice string | `audit:validate`, `audit:enrich`, `audit:payment` | clears `shipping` scope |
+
+> **Note:** `EnrichOrder` writes `carrier` and `estimatedDays` under the `"shipping"` scope using `scopeName: "shipping"`. Scoped keys are isolated from the default namespace, so a key like `"carrier"` in the `"shipping"` scope won't collide with a `"carrier"` key in the default scope.
+
+## Environment Setup
+
+See the [README.md](../../README.md) file in the parent directory for more information on how to configure the environment, including how to install and run common sample dependencies.
+
+## Running the Sample
+
+```bash
+dotnet run
+```
+
+Enter an order ID when prompted. The workflow will process the order through all four executors, streaming events as they occur:
+
+```text
+> ORD-001
+Started run: abc123
+    Wrote to shared state: taxRate = 8.5%
+    Wrote to shared state: audit:validate
+  [Output] ValidateOrder: Order 'ORD-001' validated. Customer: Jerry, Amount: $249.99
+    Read from shared state: shippingTier = Express
+    Wrote to shared state: shipping:carrier = Contoso Express
+    Wrote to shared state: shipping:estimatedDays = 2
+    Read from shared state: audit:validate (previous step: ValidateOrder)
+    Wrote to shared state: audit:enrich
+  [Output] EnrichOrder: Order enriched. Shipping: Express (previous step: ValidateOrder)
+    Read from shared state: taxRate = 8.5%
+    Wrote to shared state: audit:payment
+  [Output] ProcessPayment: Payment processed. Total: $271.24 (tax: $21.25). Ref: PAY-abc123def456
+    Read from shared state: 3 audit entries
+    Cleared shared state scope: shipping
+  [Output] GenerateInvoice: Invoice complete. Payment: "PAY-abc123def456". Audit trail: [ValidateOrder → EnrichOrder → ProcessPayment]
+  Completed: Invoice complete. Payment: "PAY-abc123def456". Audit trail: [ValidateOrder → EnrichOrder → ProcessPayment]
+```
+
+### Viewing Workflows in the DTS Dashboard
+
+After running a workflow, you can navigate to the Durable Task Scheduler (DTS) dashboard to inspect the shared state being passed between activities.
+
+If you are using the DTS emulator, the dashboard is available at `http://localhost:8082`.