.NET: Add durable workflow support (#4436)

* .NET: [Feature Branch] Add basic durable workflow support (#3648) * Add basic durable workflow support. * PR feedback fixes * Add conditional edge sample. * PR feedback fixes. * Minor cleanup. * Minor cleanup * Minor formatting improvements. * Improve comments/documentation on the execution flow. * .NET: [Feature Branch] Add Azure Functions hosting support for durable workflows (#3935) * Adding azure functions workflow support. * - PR feedback fixes. - Add example to demonstrate complex Object as payload. * rename instanceId to runId. * Use custom ITaskOrchestrator to run orchestrator function. * .NET: [Feature Branch] Adding support for events & shared state in durable workflows (#4020) * Adding support for events & shared state in durable workflows. * PR feedback fixes * PR feedback fixes. * Add YieldOutputAsync calls to 05_WorkflowEvents sample executors The integration test asserts that WorkflowOutputEvent is found in the stream, but the sample executors only used AddEventAsync for custom events and never called YieldOutputAsync. Since WorkflowOutputEvent is only emitted via explicit YieldOutputAsync calls, the assertion would fail. Added YieldOutputAsync to each executor to match the test expectation and demonstrate the API in the sample. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Fix deserialization to use shared serializer options. * PR feedback updates. * Sample cleanup * PR feedback fixes * Addressing PR review feedback for DurableStreamingWorkflowRun - Use -1 instead of 0 for taskId in TaskFailedException when task ID is not relevant. - Add [NotNullWhen(true)] to TryParseWorkflowResult out parameter following .NET TryXXX conventions. --------- Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * .NET: [Feature Branch] Add nested sub-workflow support for durable workflows (#4190) * .NET: [Feature Branch] Add nested sub-workflow support for durable workflows * fix readme path * Switch Orchestration output from string to DurableWorkflowResult. * PR feedback fixes * Minor cleanup based on PR feedback. * .NET: [Feature Branch] Add Human In the Loop support for durable workflows (#4358) * Add Azure Functions HITL workflow sample Add 06_WorkflowHITL Azure Functions sample demonstrating Human-in-the-Loop workflow support with HTTP endpoints for status checking and approval responses. The sample includes: - ExpenseReimbursement workflow with RequestPort for manager approval - Custom HTTP endpoint to check workflow status and pending approvals - Custom HTTP endpoint to send approval responses via RaiseEventAsync - demo.http file with step-by-step interaction examples * PR feedback fixes * Minor comment cleanup * Minor comment clReverted the `!context.IsReplaying` guards on `PendingEvents.Add`/`RemoveAll` and `SetCustomStatus` in `ExecuteRequestPortAsync`. The guards broke fan-out scenarios where parallel RequestPorts need to be discoverable after replay. `SetCustomStatus` is idempotent metadata that doesn't affect replay determinism.eanup * fix for PR feedback * PR feedback updates * Improvements to samples * Improvements to README * Update samples to use parallel request ports. * Unit tests * Introduce local variables to improve readability of Workflows.Workflows access patter * Use GitHub-style callouts and add PowerShell command variants in HITL sample README * Add changelog entries for durable workflow support (#4436) Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Bump Microsoft.DurableTask.Worker to 1.19.1 to fix version downgrade Microsoft.Azure.Functions.Worker.Extensions.DurableTask 1.13.1 requires Microsoft.DurableTask.Worker >= 1.19.1 via its transitive dependency on Microsoft.DurableTask.Worker.Grpc 1.19.1. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Fix broken markdown links in durable workflow sample READMEs - Create Workflow/README.md with environment setup docs - Fix ../README.md -> ../../README.md in ConsoleApps 01, 02, 03, 08 - Fix SubWorkflows relative path (3 levels -> 4 levels up) - Fix dead Durable Task Scheduler URL Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Fix build errors from main merge: Throw conflict, ExecuteAsync rename, GetNewSessionAsync rename - Remove InjectSharedThrow from DurableTask csproj (uses Workflows' internal Throw via InternalsVisibleTo) - Update ExecuteAsync -> ExecuteCoreAsync with WorkflowTelemetryContext.Disabled - Update GetNewSessionAsync -> CreateSessionAsync Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Move durable workflow samples to 04-hosting/DurableWorkflows Aligns with main branch sample reorganization where durable samples live under 04-hosting/ (alongside DurableAgents/). - Move samples/Durable/Workflow/ -> samples/04-hosting/DurableWorkflows/ - Add Directory.Build.props matching DurableAgents pattern - Update slnx project paths - Update integration test sample paths - Update README cd paths and cross-references Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Fix build errors: remove duplicate base class members, update renamed APIs - Remove duplicate OutputLog, WriteInputAsync, CreateTestTimeoutCts, etc. from ConsoleAppSamplesValidation (already in SamplesValidationBase) - Update AddFanInEdge -> AddFanInBarrierEdge in workflow samples - Update GetNewSessionAsync -> CreateSessionAsync in workflow samples - Update SourceId -> ExecutorId (obsolete) in workflow samples Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Fix dotnet format issues: add UTF-8 BOM and remove unused using - Add UTF-8 BOM to 20 .cs files across DurableTask, AzureFunctions, unit tests, and workflow samples - Remove unnecessary using directive in 07_SubWorkflows/Executors.cs Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Fix typo PaymentProcesser -> PaymentProcessor and garbled arrows in README Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Fix GetExecutorName to handle agent names with underscores Split on last underscore instead of first, and validate that the suffix is a 32-char hex string (sanitized GUID) before stripping it. This prevents truncation of agent names like 'my_agent' when the executor ID is 'my_agent_<guid>'. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Align DurableTask.Client.AzureManaged to 1.19.1 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Bump DurableTask and Azure Functions extension package versions - DurableTask.* packages: 1.19.1 -> 1.22.0 - Functions.Worker.Extensions.DurableTask: 1.13.1 -> 1.16.0 - Functions.Worker.Extensions.DurableTask.AzureManaged: 1.0.1 -> 1.5.0 (telemetry bug fix) Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Bump DurableTask SDK packages to 1.22.0 - DurableTask.Client: 1.19.1 -> 1.22.0 - DurableTask.Client.AzureManaged: 1.19.1 -> 1.22.0 - DurableTask.Worker: 1.19.1 -> 1.22.0 - DurableTask.Worker.AzureManaged: 1.19.1 -> 1.22.0 - Azure Functions extensions kept at original versions (1.13.1/1.0.1) due to host-side DurableTask.Core 3.7.0 incompatibility with newer extensions Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Update Microsoft.Azure.Functions.Worker.Extensions.DurableTask to "1.16.0" * Add the local.settings.json files to the sample which were previously ignored. This aligns with our other samples. * Increase timeout for tests as CI has them failing transiently. * increaset timeout value for azure functions integration tests. * Add YieldsOutput(string) to workflow shared state sample executors ValidateOrder and EnrichOrder call YieldOutputAsync with string messages, but only their TOutput (OrderDetails) was in the allowed yield types. This caused TargetInvocationException in the WorkflowSharedState sample validation integration test. * Downgrade the durable packages to 1.18.0 * Downgrading Worker.Extensions.DurableTask to 1.12.1 --------- Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
2026-06-16 21:04:09 +08:00 · 2026-03-16 23:00:50 +00:00
parent 0fdcfd0f4c
commit cbcdb2d29e
123 changed files with 12611 additions and 603 deletions
@@ -21,6 +21,15 @@ internal sealed class BuiltInFunctionExecutor : IFunctionExecutor
    {
        ArgumentNullException.ThrowIfNull(context);

+        // Orchestration triggers use a different input binding mechanism than other triggers.
+        // The encoded orchestrator state is retrieved via BindInputAsync on the orchestration trigger binding,
+        // not through IFunctionInputBindingFeature. Handle this case first to avoid unnecessary binding work.
+        if (context.FunctionDefinition.EntryPoint == BuiltInFunctions.RunWorkflowOrchestrationFunctionEntryPoint)
+        {
+            await ExecuteOrchestrationAsync(context);
+            return;
+        }
+
        // Acquire the input binding feature (fail fast if missing rather than null-forgiving operator).
        IFunctionInputBindingFeature? functionInputBindingFeature = context.Features.Get<IFunctionInputBindingFeature>() ??
            throw new InvalidOperationException("Function input binding feature is not available on the current context.");
@@ -57,11 +66,67 @@ internal sealed class BuiltInFunctionExecutor : IFunctionExecutor

        if (durableTaskClient is null)
        {
-            // This is not expected to happen since all built-in functions are
-            // expected to have a Durable Task client binding.
+            // This is not expected to happen since all built-in functions (other than orchestration triggers)
+            // are expected to have a Durable Task client binding.
            throw new InvalidOperationException($"Durable Task client binding is missing for the invocation {context.InvocationId}.");
        }

+        if (context.FunctionDefinition.EntryPoint == BuiltInFunctions.RunWorkflowOrchestrationHttpFunctionEntryPoint)
+        {
+            if (httpRequestData == null)
+            {
+                throw new InvalidOperationException($"HTTP request data binding is missing for the invocation {context.InvocationId}.");
+            }
+
+            context.GetInvocationResult().Value = await BuiltInFunctions.RunWorkflowOrchestrationHttpTriggerAsync(
+                httpRequestData,
+                durableTaskClient,
+                context);
+            return;
+        }
+
+        if (context.FunctionDefinition.EntryPoint == BuiltInFunctions.GetWorkflowStatusHttpFunctionEntryPoint)
+        {
+            if (httpRequestData == null)
+            {
+                throw new InvalidOperationException($"HTTP request data binding is missing for the invocation {context.InvocationId}.");
+            }
+
+            context.GetInvocationResult().Value = await BuiltInFunctions.GetWorkflowStatusAsync(
+                httpRequestData,
+                durableTaskClient,
+                context);
+            return;
+        }
+
+        if (context.FunctionDefinition.EntryPoint == BuiltInFunctions.RespondToWorkflowHttpFunctionEntryPoint)
+        {
+            if (httpRequestData == null)
+            {
+                throw new InvalidOperationException($"HTTP request data binding is missing for the invocation {context.InvocationId}.");
+            }
+
+            context.GetInvocationResult().Value = await BuiltInFunctions.RespondToWorkflowAsync(
+                httpRequestData,
+                durableTaskClient,
+                context);
+            return;
+        }
+
+        if (context.FunctionDefinition.EntryPoint == BuiltInFunctions.InvokeWorkflowActivityFunctionEntryPoint)
+        {
+            if (encodedEntityRequest is null)
+            {
+                throw new InvalidOperationException($"Activity trigger input binding is missing for the invocation {context.InvocationId}.");
+            }
+
+            context.GetInvocationResult().Value = await BuiltInFunctions.InvokeWorkflowActivityAsync(
+                encodedEntityRequest,
+                durableTaskClient,
+                context);
+            return;
+        }
+
        if (context.FunctionDefinition.EntryPoint == BuiltInFunctions.RunAgentHttpFunctionEntryPoint)
        {
            if (httpRequestData == null)
@@ -70,9 +135,9 @@ internal sealed class BuiltInFunctionExecutor : IFunctionExecutor
            }

            context.GetInvocationResult().Value = await BuiltInFunctions.RunAgentHttpAsync(
-                   httpRequestData,
-                   durableTaskClient,
-                   context);
+                httpRequestData,
+                durableTaskClient,
+                context);
            return;
        }

@@ -104,4 +169,32 @@ internal sealed class BuiltInFunctionExecutor : IFunctionExecutor

        throw new InvalidOperationException($"Unsupported function entry point '{context.FunctionDefinition.EntryPoint}' for invocation {context.InvocationId}.");
    }
+
+    private static async ValueTask ExecuteOrchestrationAsync(FunctionContext context)
+    {
+        BindingMetadata? orchestrationBinding = null;
+        foreach (BindingMetadata binding in context.FunctionDefinition.InputBindings.Values)
+        {
+            if (string.Equals(binding.Type, "orchestrationTrigger", StringComparison.OrdinalIgnoreCase))
+            {
+                orchestrationBinding = binding;
+                break;
+            }
+        }
+
+        if (orchestrationBinding is null)
+        {
+            throw new InvalidOperationException($"Orchestration trigger binding is missing for the invocation {context.InvocationId}.");
+        }
+
+        InputBindingData<object> triggerInputData = await context.BindInputAsync<object>(orchestrationBinding);
+        if (triggerInputData?.Value is not string encodedOrchestratorState)
+        {
+            throw new InvalidOperationException($"Orchestration history state was either missing from the input or not a string value for invocation {context.InvocationId}.");
+        }
+
+        context.GetInvocationResult().Value = BuiltInFunctions.RunWorkflowOrchestration(
+            encodedOrchestratorState,
+            context);
+    }
 }
@@ -1,11 +1,14 @@
 // Copyright (c) Microsoft. All rights reserved.

 using System.Net;
+using System.Text.Json;
 using System.Text.Json.Serialization;
 using Microsoft.Agents.AI.DurableTask;
+using Microsoft.Agents.AI.DurableTask.Workflows;
 using Microsoft.Azure.Functions.Worker;
 using Microsoft.Azure.Functions.Worker.Extensions.Mcp;
 using Microsoft.Azure.Functions.Worker.Http;
+using Microsoft.DurableTask;
 using Microsoft.DurableTask.Client;
 using Microsoft.DurableTask.Worker.Grpc;
 using Microsoft.Extensions.AI;
@@ -21,6 +24,203 @@ internal static class BuiltInFunctions
    internal static readonly string RunAgentHttpFunctionEntryPoint = $"{typeof(BuiltInFunctions).FullName!}.{nameof(RunAgentHttpAsync)}";
    internal static readonly string RunAgentEntityFunctionEntryPoint = $"{typeof(BuiltInFunctions).FullName!}.{nameof(InvokeAgentAsync)}";
    internal static readonly string RunAgentMcpToolFunctionEntryPoint = $"{typeof(BuiltInFunctions).FullName!}.{nameof(RunMcpToolAsync)}";
+    internal static readonly string RunWorkflowOrchestrationHttpFunctionEntryPoint = $"{typeof(BuiltInFunctions).FullName!}.{nameof(RunWorkflowOrchestrationHttpTriggerAsync)}";
+    internal static readonly string RunWorkflowOrchestrationFunctionEntryPoint = $"{typeof(BuiltInFunctions).FullName!}.{nameof(RunWorkflowOrchestration)}";
+    internal static readonly string InvokeWorkflowActivityFunctionEntryPoint = $"{typeof(BuiltInFunctions).FullName!}.{nameof(InvokeWorkflowActivityAsync)}";
+    internal static readonly string GetWorkflowStatusHttpFunctionEntryPoint = $"{typeof(BuiltInFunctions).FullName!}.{nameof(GetWorkflowStatusAsync)}";
+    internal static readonly string RespondToWorkflowHttpFunctionEntryPoint = $"{typeof(BuiltInFunctions).FullName!}.{nameof(RespondToWorkflowAsync)}";
+
+#pragma warning disable IL3000 // Avoid accessing Assembly file path when publishing as a single file - Azure Functions does not use single-file publishing
+    internal static readonly string ScriptFile = Path.GetFileName(typeof(BuiltInFunctions).Assembly.Location);
+#pragma warning restore IL3000
+
+    /// <summary>
+    /// Starts a workflow orchestration in response to an HTTP request.
+    /// The workflow name is derived from the function name by stripping the <see cref="HttpPrefix"/>.
+    /// Callers can optionally provide a custom run ID via the <c>runId</c> query string parameter
+    /// (e.g., <c>/api/workflows/MyWorkflow/run?runId=my-id</c>). If not provided, one is auto-generated.
+    /// </summary>
+    public static async Task<HttpResponseData> RunWorkflowOrchestrationHttpTriggerAsync(
+        [HttpTrigger] HttpRequestData req,
+        [DurableClient] DurableTaskClient client,
+        FunctionContext context)
+    {
+        string workflowName = context.FunctionDefinition.Name.Replace(HttpPrefix, string.Empty);
+        string orchestrationFunctionName = WorkflowNamingHelper.ToOrchestrationFunctionName(workflowName);
+        string? inputMessage = await req.ReadAsStringAsync();
+
+        if (string.IsNullOrEmpty(inputMessage))
+        {
+            return await CreateErrorResponseAsync(req, context, HttpStatusCode.BadRequest, "Workflow input cannot be empty.");
+        }
+
+        DurableWorkflowInput<string> orchestrationInput = new() { Input = inputMessage };
+
+        // Allow users to provide a custom run ID via query string; otherwise, auto-generate one.
+        string? instanceId = req.Query["runId"];
+        StartOrchestrationOptions? options = instanceId is not null ? new StartOrchestrationOptions(instanceId) : null;
+        string resolvedInstanceId = await client.ScheduleNewOrchestrationInstanceAsync(orchestrationFunctionName, orchestrationInput, options);
+
+        HttpResponseData response = req.CreateResponse(HttpStatusCode.Accepted);
+        await response.WriteStringAsync($"Workflow orchestration started for {workflowName}. Orchestration runId: {resolvedInstanceId}");
+        return response;
+    }
+
+    /// <summary>
+    /// Returns the workflow status including any pending HITL requests.
+    /// The run ID is extracted from the route parameter <c>{runId}</c>.
+    /// </summary>
+    public static async Task<HttpResponseData> GetWorkflowStatusAsync(
+        [HttpTrigger] HttpRequestData req,
+        [DurableClient] DurableTaskClient client,
+        FunctionContext context)
+    {
+        string? runId = context.BindingContext.BindingData.TryGetValue("runId", out object? value) ? value?.ToString() : null;
+        if (string.IsNullOrEmpty(runId))
+        {
+            return await CreateErrorResponseAsync(req, context, HttpStatusCode.BadRequest, "Run ID is required.");
+        }
+
+        OrchestrationMetadata? metadata = await client.GetInstanceAsync(runId, getInputsAndOutputs: true);
+        if (metadata is null)
+        {
+            return await CreateErrorResponseAsync(req, context, HttpStatusCode.NotFound, $"Workflow run '{runId}' not found.");
+        }
+
+        // Parse HITL inputs the workflow is waiting for from the durable workflow status
+        List<PendingRequestPortStatus>? waitingForInput = null;
+        if (DurableWorkflowLiveStatus.TryParse(metadata.SerializedCustomStatus, out DurableWorkflowLiveStatus liveStatus)
+            && liveStatus.PendingEvents.Count > 0)
+        {
+            waitingForInput = liveStatus.PendingEvents;
+        }
+
+        HttpResponseData response = req.CreateResponse(HttpStatusCode.OK);
+        await response.WriteAsJsonAsync(new
+        {
+            runId,
+            status = metadata.RuntimeStatus.ToString(),
+            waitingForInput = waitingForInput?.Select(p => new { eventName = p.EventName, input = JsonDocument.Parse(p.Input).RootElement })
+        });
+        return response;
+    }
+
+    /// <summary>
+    /// Sends a response to a pending RequestPort, resuming the workflow.
+    /// Expects a JSON body: <c>{ "eventName": "...", "response": { ... } }</c>.
+    /// </summary>
+    public static async Task<HttpResponseData> RespondToWorkflowAsync(
+        [HttpTrigger] HttpRequestData req,
+        [DurableClient] DurableTaskClient client,
+        FunctionContext context)
+    {
+        string? runId = context.BindingContext.BindingData.TryGetValue("runId", out object? value) ? value?.ToString() : null;
+        if (string.IsNullOrEmpty(runId))
+        {
+            return await CreateErrorResponseAsync(req, context, HttpStatusCode.BadRequest, "Run ID is required.");
+        }
+
+        WorkflowRespondRequest? request;
+        try
+        {
+            request = await req.ReadFromJsonAsync<WorkflowRespondRequest>(context.CancellationToken);
+        }
+        catch (JsonException)
+        {
+            return await CreateErrorResponseAsync(req, context, HttpStatusCode.BadRequest, "Request body is not valid JSON.");
+        }
+
+        if (request is null || string.IsNullOrEmpty(request.EventName)
+            || request.Response.ValueKind == JsonValueKind.Undefined)
+        {
+            return await CreateErrorResponseAsync(req, context, HttpStatusCode.BadRequest, "Body must contain a non-empty 'eventName' and a 'response' property.");
+        }
+
+        // Verify the orchestration exists and is in a valid state
+        OrchestrationMetadata? metadata = await client.GetInstanceAsync(runId, getInputsAndOutputs: true);
+        if (metadata is null)
+        {
+            return await CreateErrorResponseAsync(req, context, HttpStatusCode.NotFound, $"Workflow run '{runId}' not found.");
+        }
+
+        if (metadata.RuntimeStatus is OrchestrationRuntimeStatus.Completed
+            or OrchestrationRuntimeStatus.Failed
+            or OrchestrationRuntimeStatus.Terminated)
+        {
+            return await CreateErrorResponseAsync(req, context, HttpStatusCode.BadRequest,
+                $"Workflow run '{runId}' is in terminal state '{metadata.RuntimeStatus}'.");
+        }
+
+        // Verify the workflow is waiting for the specified event.
+        // If status can't be parsed (e.g., not yet set during early execution), allow the event through —
+        // Durable Task safely queues it until the orchestration reaches WaitForExternalEvent.
+        bool eventValidated = false;
+        if (DurableWorkflowLiveStatus.TryParse(metadata.SerializedCustomStatus, out DurableWorkflowLiveStatus liveStatus))
+        {
+            if (!liveStatus.PendingEvents.Exists(p => string.Equals(p.EventName, request.EventName, StringComparison.Ordinal)))
+            {
+                return await CreateErrorResponseAsync(req, context, HttpStatusCode.BadRequest,
+                    $"Workflow is not waiting for event '{request.EventName}'.");
+            }
+
+            eventValidated = true;
+        }
+
+        // Raise the external event to unblock the orchestration's WaitForExternalEvent call
+        await client.RaiseEventAsync(runId, request.EventName, request.Response.GetRawText());
+
+        HttpResponseData response = req.CreateResponse(HttpStatusCode.Accepted);
+        await response.WriteAsJsonAsync(new
+        {
+            message = eventValidated
+                ? "Response sent to workflow."
+                : "Response sent to workflow. Event could not be validated against pending requests.",
+            runId,
+            eventName = request.EventName,
+            validated = eventValidated,
+        });
+        return response;
+    }
+
+    /// <summary>
+    /// Executes a workflow activity by looking up the registered executor and delegating to it.
+    /// The executor name is derived from the activity function name via <see cref="WorkflowNamingHelper"/>.
+    /// </summary>
+    public static Task<string> InvokeWorkflowActivityAsync(
+        [ActivityTrigger] string input,
+        [DurableClient] DurableTaskClient durableTaskClient,
+        FunctionContext functionContext)
+    {
+        ArgumentNullException.ThrowIfNull(input);
+        ArgumentNullException.ThrowIfNull(durableTaskClient);
+        ArgumentNullException.ThrowIfNull(functionContext);
+
+        string activityFunctionName = functionContext.FunctionDefinition.Name;
+        string executorName = WorkflowNamingHelper.ToWorkflowName(activityFunctionName);
+
+        DurableOptions durableOptions = functionContext.InstanceServices.GetRequiredService<DurableOptions>();
+        if (!durableOptions.Workflows.Executors.TryGetExecutor(executorName, out ExecutorRegistration? registration))
+        {
+            throw new InvalidOperationException($"Executor '{executorName}' not found in workflow options.");
+        }
+
+        return DurableActivityExecutor.ExecuteAsync(registration.Binding, input, functionContext.CancellationToken);
+    }
+
+    /// <summary>
+    /// Runs a workflow orchestration by delegating to <see cref="WorkflowOrchestrator"/>
+    /// via <see cref="GrpcOrchestrationRunner"/>.
+    /// </summary>
+    public static string RunWorkflowOrchestration(
+        string encodedOrchestratorRequest,
+        FunctionContext functionContext)
+    {
+        ArgumentNullException.ThrowIfNull(encodedOrchestratorRequest);
+        ArgumentNullException.ThrowIfNull(functionContext);
+
+        WorkflowOrchestrator orchestrator = new(functionContext.InstanceServices);
+        return GrpcOrchestrationRunner.LoadAndRun(encodedOrchestratorRequest, orchestrator, functionContext.InstanceServices);
+    }

    // Exposed as an entity trigger via AgentFunctionsProvider
    public static Task<string> InvokeAgentAsync(
@@ -332,6 +532,15 @@ internal static class BuiltInFunctions
        [property: JsonPropertyName("status")] int Status,
        [property: JsonPropertyName("thread_id")] string ThreadId);

+    /// <summary>
+    /// Represents a request to respond to a pending RequestPort in a workflow.
+    /// </summary>
+    /// <param name="EventName">The name of the event to raise (the RequestPort ID).</param>
+    /// <param name="Response">The response payload to send to the workflow.</param>
+    private sealed record WorkflowRespondRequest(
+        [property: JsonPropertyName("eventName")] string? EventName,
+        [property: JsonPropertyName("response")] JsonElement Response);
+
    /// <summary>
    /// A service provider that combines the original service provider with an additional DurableTaskClient instance.
    /// </summary>
@@ -1,6 +1,10 @@
 # Release History

-## <version>
+## [Unreleased]
+
+- Added Azure Functions hosting support for durable workflows ([#4436](https://github.com/microsoft/agent-framework/pull/4436))
+
+## v1.0.0-preview.251219.1

 - Addressed incompatibility issue with `Microsoft.Azure.Functions.Worker.Extensions.DurableTask` >= 1.11.0 ([#2759](https://github.com/microsoft/agent-framework/pull/2759))

@@ -1,6 +1,5 @@
 // Copyright (c) Microsoft. All rights reserved.

-using Microsoft.Agents.AI.DurableTask;
 using Microsoft.Azure.Functions.Worker.Core.FunctionMetadata;
 using Microsoft.Extensions.Logging;

@@ -17,10 +16,6 @@ internal sealed class DurableAgentFunctionMetadataTransformer : IFunctionMetadat
    private readonly IServiceProvider _serviceProvider;
    private readonly IFunctionsAgentOptionsProvider _functionsAgentOptionsProvider;

-#pragma warning disable IL3000 // Avoid accessing Assembly file path when publishing as a single file - Azure Functions does not use single-file publishing
-    private static readonly string s_builtInFunctionsScriptFile = Path.GetFileName(typeof(BuiltInFunctions).Assembly.Location);
-#pragma warning restore IL3000
-
    public DurableAgentFunctionMetadataTransformer(
        IReadOnlyDictionary<string, Func<IServiceProvider, AIAgent>> agents,
        ILogger<DurableAgentFunctionMetadataTransformer> logger,
@@ -45,14 +40,14 @@ internal sealed class DurableAgentFunctionMetadataTransformer : IFunctionMetadat

            this._logger.LogRegisteringTriggerForAgent(agentName, "entity");

-            original.Add(CreateAgentTrigger(agentName));
+            original.Add(FunctionMetadataFactory.CreateEntityTrigger(agentName));

            if (this._functionsAgentOptionsProvider.TryGet(agentName, out FunctionsAgentOptions? agentTriggerOptions))
            {
                if (agentTriggerOptions.HttpTrigger.IsEnabled)
                {
                    this._logger.LogRegisteringTriggerForAgent(agentName, "http");
-                    original.Add(CreateHttpTrigger(agentName, $"agents/{agentName}/run"));
+                    original.Add(FunctionMetadataFactory.CreateHttpTrigger(agentName, $"agents/{agentName}/run", BuiltInFunctions.RunAgentHttpFunctionEntryPoint));
                }

                if (agentTriggerOptions.McpToolTrigger.IsEnabled)
@@ -65,39 +60,6 @@ internal sealed class DurableAgentFunctionMetadataTransformer : IFunctionMetadat
        }
    }

-    private static DefaultFunctionMetadata CreateAgentTrigger(string name)
-    {
-        return new DefaultFunctionMetadata()
-        {
-            Name = AgentSessionId.ToEntityName(name),
-            Language = "dotnet-isolated",
-            RawBindings =
-            [
-                """{"name":"encodedEntityRequest","type":"entityTrigger","direction":"In"}""",
-                """{"name":"client","type":"durableClient","direction":"In"}"""
-            ],
-            EntryPoint = BuiltInFunctions.RunAgentEntityFunctionEntryPoint,
-            ScriptFile = s_builtInFunctionsScriptFile,
-        };
-    }
-
-    private static DefaultFunctionMetadata CreateHttpTrigger(string name, string route)
-    {
-        return new DefaultFunctionMetadata()
-        {
-            Name = $"{BuiltInFunctions.HttpPrefix}{name}",
-            Language = "dotnet-isolated",
-            RawBindings =
-            [
-                $"{{\"name\":\"req\",\"type\":\"httpTrigger\",\"direction\":\"In\",\"authLevel\":\"function\",\"methods\": [\"post\"],\"route\":\"{route}\"}}",
-                "{\"name\":\"$return\",\"type\":\"http\",\"direction\":\"Out\"}",
-                "{\"name\":\"client\",\"type\":\"durableClient\",\"direction\":\"In\"}"
-            ],
-            EntryPoint = BuiltInFunctions.RunAgentHttpFunctionEntryPoint,
-            ScriptFile = s_builtInFunctionsScriptFile,
-        };
-    }
-
    private static DefaultFunctionMetadata CreateMcpToolTrigger(string agentName, string? description)
    {
        return new DefaultFunctionMetadata
@@ -112,7 +74,7 @@ internal sealed class DurableAgentFunctionMetadataTransformer : IFunctionMetadat
                """{"name":"client","type":"durableClient","direction":"In"}"""
            ],
            EntryPoint = BuiltInFunctions.RunAgentMcpToolFunctionEntryPoint,
-            ScriptFile = s_builtInFunctionsScriptFile,
+            ScriptFile = BuiltInFunctions.ScriptFile,
        };
    }
 }
@@ -0,0 +1,101 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using Microsoft.Agents.AI.DurableTask;
+using Microsoft.Azure.Functions.Worker.Core.FunctionMetadata;
+
+namespace Microsoft.Agents.AI.Hosting.AzureFunctions;
+
+/// <summary>
+/// Provides factory methods for creating common <see cref="DefaultFunctionMetadata"/> instances
+/// used by function metadata transformers.
+/// </summary>
+internal static class FunctionMetadataFactory
+{
+    /// <summary>
+    /// Creates function metadata for an entity trigger function.
+    /// </summary>
+    /// <param name="name">The base name used to derive the entity function name.</param>
+    /// <returns>A <see cref="DefaultFunctionMetadata"/> configured for an entity trigger.</returns>
+    internal static DefaultFunctionMetadata CreateEntityTrigger(string name)
+    {
+        return new DefaultFunctionMetadata()
+        {
+            Name = AgentSessionId.ToEntityName(name),
+            Language = "dotnet-isolated",
+            RawBindings =
+            [
+                """{"name":"encodedEntityRequest","type":"entityTrigger","direction":"In"}""",
+                """{"name":"client","type":"durableClient","direction":"In"}"""
+            ],
+            EntryPoint = BuiltInFunctions.RunAgentEntityFunctionEntryPoint,
+            ScriptFile = BuiltInFunctions.ScriptFile,
+        };
+    }
+
+    /// <summary>
+    /// Creates function metadata for an HTTP trigger function.
+    /// </summary>
+    /// <param name="name">The base name used to derive the HTTP function name.</param>
+    /// <param name="route">The HTTP route for the trigger.</param>
+    /// <param name="entryPoint">The entry point method for the HTTP trigger.</param>
+    /// <param name="methods">The allowed HTTP methods as a JSON array fragment (e.g., <c>"\"get\""</c>). Defaults to POST.</param>
+    /// <returns>A <see cref="DefaultFunctionMetadata"/> configured for an HTTP trigger.</returns>
+    internal static DefaultFunctionMetadata CreateHttpTrigger(string name, string route, string entryPoint, string methods = "\"post\"")
+    {
+        return new DefaultFunctionMetadata()
+        {
+            Name = $"{BuiltInFunctions.HttpPrefix}{name}",
+            Language = "dotnet-isolated",
+            RawBindings =
+            [
+                $"{{\"name\":\"req\",\"type\":\"httpTrigger\",\"direction\":\"In\",\"authLevel\":\"function\",\"methods\": [{methods}],\"route\":\"{route}\"}}",
+                "{\"name\":\"$return\",\"type\":\"http\",\"direction\":\"Out\"}",
+                "{\"name\":\"client\",\"type\":\"durableClient\",\"direction\":\"In\"}"
+            ],
+            EntryPoint = entryPoint,
+            ScriptFile = BuiltInFunctions.ScriptFile,
+        };
+    }
+
+    /// <summary>
+    /// Creates function metadata for an activity trigger function.
+    /// </summary>
+    /// <param name="functionName">The name of the activity function.</param>
+    /// <returns>A <see cref="DefaultFunctionMetadata"/> configured for an activity trigger.</returns>
+    internal static DefaultFunctionMetadata CreateActivityTrigger(string functionName)
+    {
+        return new DefaultFunctionMetadata()
+        {
+            Name = functionName,
+            Language = "dotnet-isolated",
+            RawBindings =
+            [
+                """{"name":"input","type":"activityTrigger","direction":"In","dataType":"String"}""",
+                """{"name":"durableTaskClient","type":"durableClient","direction":"In"}"""
+            ],
+            EntryPoint = BuiltInFunctions.InvokeWorkflowActivityFunctionEntryPoint,
+            ScriptFile = BuiltInFunctions.ScriptFile,
+        };
+    }
+
+    /// <summary>
+    /// Creates function metadata for an orchestration trigger function.
+    /// </summary>
+    /// <param name="functionName">The name of the orchestration function.</param>
+    /// <param name="entryPoint">The entry point method for the orchestration trigger.</param>
+    /// <returns>A <see cref="DefaultFunctionMetadata"/> configured for an orchestration trigger.</returns>
+    internal static DefaultFunctionMetadata CreateOrchestrationTrigger(string functionName, string entryPoint)
+    {
+        return new DefaultFunctionMetadata()
+        {
+            Name = functionName,
+            Language = "dotnet-isolated",
+            RawBindings =
+            [
+                """{"name":"context","type":"orchestrationTrigger","direction":"In"}"""
+            ],
+            EntryPoint = entryPoint,
+            ScriptFile = BuiltInFunctions.ScriptFile,
+        };
+    }
+}
@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft. All rights reserved.

 using Microsoft.Agents.AI.DurableTask;
+using Microsoft.Agents.AI.DurableTask.Workflows;
 using Microsoft.Azure.Functions.Worker.Builder;
 using Microsoft.Azure.Functions.Worker.Core.FunctionMetadata;
 using Microsoft.Extensions.DependencyInjection;
@@ -43,4 +44,90 @@ public static class FunctionsApplicationBuilderExtensions

        return builder;
    }
+
+    /// <summary>
+    /// Configures durable options for the functions application, allowing customization of Durable Task framework
+    /// settings.
+    /// </summary>
+    /// <remarks>This method ensures that a single shared <see cref="DurableOptions"/> instance is used across all
+    /// configuration calls. If any workflows have been added, it configures the necessary orchestrations and registers
+    /// required middleware.</remarks>
+    /// <param name="builder">The functions application builder to configure. Cannot be null.</param>
+    /// <param name="configure">An action that configures the <see cref="DurableOptions"/> instance. Cannot be null.</param>
+    /// <returns>The updated <see cref="FunctionsApplicationBuilder"/> instance, enabling method chaining.</returns>
+    public static FunctionsApplicationBuilder ConfigureDurableOptions(
+        this FunctionsApplicationBuilder builder,
+        Action<DurableOptions> configure)
+    {
+        ArgumentNullException.ThrowIfNull(builder);
+        ArgumentNullException.ThrowIfNull(configure);
+
+        // Ensure FunctionsDurableOptions is registered BEFORE the core extension creates a plain DurableOptions
+        FunctionsDurableOptions sharedOptions = GetOrCreateSharedOptions(builder.Services);
+
+        builder.Services.ConfigureDurableOptions(configure);
+
+        if (sharedOptions.Workflows.Workflows.Count > 0)
+        {
+            builder.Services.TryAddEnumerable(ServiceDescriptor.Singleton<IFunctionMetadataTransformer, DurableWorkflowsFunctionMetadataTransformer>());
+        }
+
+        EnsureMiddlewareRegistered(builder);
+
+        return builder;
+    }
+
+    /// <summary>
+    /// Configures durable workflow support for the specified Azure Functions application builder.
+    /// </summary>
+    /// <param name="builder">The <see cref="FunctionsApplicationBuilder"/> instance to configure for durable workflows.</param>
+    /// <param name="configure">An action that configures the <see cref="DurableWorkflowOptions"/>, allowing customization of durable workflow behavior.</param>
+    /// <returns>The updated <see cref="FunctionsApplicationBuilder"/> instance, enabling method chaining.</returns>
+    public static FunctionsApplicationBuilder ConfigureDurableWorkflows(
+         this FunctionsApplicationBuilder builder,
+         Action<DurableWorkflowOptions> configure)
+    {
+        ArgumentNullException.ThrowIfNull(configure);
+
+        return builder.ConfigureDurableOptions(options => configure(options.Workflows));
+    }
+
+    private static void EnsureMiddlewareRegistered(FunctionsApplicationBuilder builder)
+    {
+        // Guard against registering the middleware filter multiple times in the pipeline.
+        if (builder.Services.Any(d => d.ServiceType == typeof(BuiltInFunctionExecutor)))
+        {
+            return;
+        }
+
+        builder.UseWhen<BuiltInFunctionExecutionMiddleware>(static context =>
+            string.Equals(context.FunctionDefinition.EntryPoint, BuiltInFunctions.RunAgentHttpFunctionEntryPoint, StringComparison.Ordinal) ||
+            string.Equals(context.FunctionDefinition.EntryPoint, BuiltInFunctions.RunAgentEntityFunctionEntryPoint, StringComparison.Ordinal) ||
+            string.Equals(context.FunctionDefinition.EntryPoint, BuiltInFunctions.RunWorkflowOrchestrationHttpFunctionEntryPoint, StringComparison.Ordinal) ||
+            string.Equals(context.FunctionDefinition.EntryPoint, BuiltInFunctions.RunWorkflowOrchestrationFunctionEntryPoint, StringComparison.Ordinal) ||
+            string.Equals(context.FunctionDefinition.EntryPoint, BuiltInFunctions.InvokeWorkflowActivityFunctionEntryPoint, StringComparison.Ordinal) ||
+            string.Equals(context.FunctionDefinition.EntryPoint, BuiltInFunctions.GetWorkflowStatusHttpFunctionEntryPoint, StringComparison.Ordinal) ||
+            string.Equals(context.FunctionDefinition.EntryPoint, BuiltInFunctions.RespondToWorkflowHttpFunctionEntryPoint, StringComparison.Ordinal)
+        );
+        builder.Services.TryAddSingleton<BuiltInFunctionExecutor>();
+    }
+
+    /// <summary>
+    /// Gets or creates a shared <see cref="DurableOptions"/> instance from the service collection.
+    /// </summary>
+    private static FunctionsDurableOptions GetOrCreateSharedOptions(IServiceCollection services)
+    {
+        ServiceDescriptor? existingDescriptor = services.FirstOrDefault(
+            d => d.ServiceType == typeof(DurableOptions) && d.ImplementationInstance is not null);
+
+        if (existingDescriptor?.ImplementationInstance is FunctionsDurableOptions existing)
+        {
+            return existing;
+        }
+
+        FunctionsDurableOptions options = new();
+        services.AddSingleton<DurableOptions>(options);
+        services.AddSingleton(options);
+        return options;
+    }
 }
@@ -0,0 +1,29 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using Microsoft.Agents.AI.DurableTask;
+
+namespace Microsoft.Agents.AI.Hosting.AzureFunctions;
+
+/// <summary>
+/// Provides Azure Functions–specific configuration for durable workflows.
+/// </summary>
+internal sealed class FunctionsDurableOptions : DurableOptions
+{
+    private readonly HashSet<string> _statusEndpointWorkflows = new(StringComparer.OrdinalIgnoreCase);
+
+    /// <summary>
+    /// Enables the status HTTP endpoint for the specified workflow.
+    /// </summary>
+    internal void EnableStatusEndpoint(string workflowName)
+    {
+        this._statusEndpointWorkflows.Add(workflowName);
+    }
+
+    /// <summary>
+    /// Returns whether the status endpoint is enabled for the specified workflow.
+    /// </summary>
+    internal bool IsStatusEndpointEnabled(string workflowName)
+    {
+        return this._statusEndpointWorkflows.Contains(workflowName);
+    }
+}
@@ -17,4 +17,16 @@ internal static partial class Logs
        Level = LogLevel.Information,
        Message = "Registering {TriggerType} function for agent '{AgentName}'")]
    public static partial void LogRegisteringTriggerForAgent(this ILogger logger, string agentName, string triggerType);
+
+    [LoggerMessage(
+        EventId = 102,
+        Level = LogLevel.Information,
+        Message = "Registering {TriggerType} trigger function '{FunctionName}' for workflow '{WorkflowKey}'")]
+    public static partial void LogRegisteringWorkflowTrigger(this ILogger logger, string workflowKey, string functionName, string triggerType);
+
+    [LoggerMessage(
+        EventId = 103,
+        Level = LogLevel.Information,
+        Message = "Function metadata transformation complete. Added {AddedCount} workflow function(s). Total function count: {TotalCount}")]
+    public static partial void LogTransformationComplete(this ILogger logger, int addedCount, int totalCount);
 }
@@ -4,7 +4,8 @@
    <TargetFrameworks>$(TargetFrameworksCore)</TargetFrameworks>
    <ImplicitUsings>enable</ImplicitUsings>
    <!-- CA2007: This rule should generally be suppressed in Durable Task libraries. Also, this is not library code. -->
-    <NoWarn>$(NoWarn);CA2007</NoWarn>
+    <!-- AD0001: Temporary workaround for Microsoft.DurableTask.Analyzers v0.2.0 bug (ArgumentNullException on 'node'). Remove when upgrading to a fixed analyzer version. -->
+    <NoWarn>$(NoWarn);CA2007;AD0001</NoWarn>
  </PropertyGroup>

  <Import Project="$(RepoRoot)/dotnet/nuget/nuget-package.props" />
@@ -0,0 +1,30 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using Microsoft.Agents.AI.DurableTask.Workflows;
+using Microsoft.Agents.AI.Workflows;
+
+namespace Microsoft.Agents.AI.Hosting.AzureFunctions;
+
+/// <summary>
+/// Extension methods for <see cref="DurableWorkflowOptions"/> to configure Azure Functions HTTP trigger options.
+/// </summary>
+public static class DurableWorkflowOptionsExtensions
+{
+    /// <summary>
+    /// Adds a workflow and optionally exposes a status HTTP endpoint for querying pending HITL requests.
+    /// </summary>
+    /// <param name="options">The workflow options to add the workflow to.</param>
+    /// <param name="workflow">The workflow instance to add.</param>
+    /// <param name="exposeStatusEndpoint">If <see langword="true"/>, a GET endpoint is generated at <c>workflows/{name}/status/{runId}</c>.</param>
+    public static void AddWorkflow(this DurableWorkflowOptions options, Workflow workflow, bool exposeStatusEndpoint)
+    {
+        ArgumentNullException.ThrowIfNull(options);
+
+        options.AddWorkflow(workflow);
+
+        if (exposeStatusEndpoint && options.ParentOptions is FunctionsDurableOptions functionsOptions)
+        {
+            functionsOptions.EnableStatusEndpoint(workflow.Name!);
+        }
+    }
+}
@@ -0,0 +1,152 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using Microsoft.Agents.AI.DurableTask;
+using Microsoft.Agents.AI.DurableTask.Workflows;
+using Microsoft.Agents.AI.Workflows;
+using Microsoft.Azure.Functions.Worker.Core.FunctionMetadata;
+using Microsoft.Extensions.Logging;
+
+namespace Microsoft.Agents.AI.Hosting.AzureFunctions;
+
+/// <summary>
+/// Transforms function metadata by dynamically registering Azure Functions triggers
+/// for each configured durable workflow and its executors.
+/// </summary>
+/// <remarks>
+/// For each workflow, this transformer registers:
+/// <list type="bullet">
+///   <item><description>An HTTP trigger function to start the workflow orchestration via HTTP.</description></item>
+///   <item><description>An orchestration trigger function to run the workflow orchestration.</description></item>
+///   <item><description>An activity trigger function for each non-agent executor in the workflow.</description></item>
+///   <item><description>An entity trigger function for each AI agent executor in the workflow.</description></item>
+/// </list>
+/// When multiple workflows share the same executor, the corresponding function is registered only once.
+/// </remarks>
+internal sealed class DurableWorkflowsFunctionMetadataTransformer : IFunctionMetadataTransformer
+{
+    private readonly ILogger<DurableWorkflowsFunctionMetadataTransformer> _logger;
+    private readonly FunctionsDurableOptions _options;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="DurableWorkflowsFunctionMetadataTransformer"/> class.
+    /// </summary>
+    /// <param name="logger">The logger instance for diagnostic output.</param>
+    /// <param name="durableOptions">The durable options containing workflow configurations.</param>
+    public DurableWorkflowsFunctionMetadataTransformer(
+        ILogger<DurableWorkflowsFunctionMetadataTransformer> logger,
+        FunctionsDurableOptions durableOptions)
+    {
+        this._logger = logger ?? throw new ArgumentNullException(nameof(logger));
+        ArgumentNullException.ThrowIfNull(durableOptions);
+        this._options = durableOptions;
+    }
+
+    /// <inheritdoc />
+    public string Name => nameof(DurableWorkflowsFunctionMetadataTransformer);
+
+    /// <inheritdoc />
+    public void Transform(IList<IFunctionMetadata> original)
+    {
+        int initialCount = original.Count;
+        this._logger.LogTransformingFunctionMetadata(initialCount);
+
+        // Track registered function names to avoid duplicates when workflows share executors.
+        HashSet<string> registeredFunctions = [];
+
+        DurableWorkflowOptions workflowOptions = this._options.Workflows;
+        foreach (var workflow in workflowOptions.Workflows)
+        {
+            string httpFunctionName = $"{BuiltInFunctions.HttpPrefix}{workflow.Key}";
+
+            if (this._logger.IsEnabled(LogLevel.Information))
+            {
+                this._logger.LogInformation("Registering durable workflow functions for workflow '{WorkflowKey}' with HTTP trigger function name '{HttpFunctionName}'", workflow.Key, httpFunctionName);
+            }
+
+            // Register an orchestration function for the workflow.
+            string orchestrationFunctionName = WorkflowNamingHelper.ToOrchestrationFunctionName(workflow.Key);
+            if (registeredFunctions.Add(orchestrationFunctionName))
+            {
+                this._logger.LogRegisteringWorkflowTrigger(workflow.Key, orchestrationFunctionName, "orchestration");
+                original.Add(FunctionMetadataFactory.CreateOrchestrationTrigger(
+                    orchestrationFunctionName,
+                    BuiltInFunctions.RunWorkflowOrchestrationFunctionEntryPoint));
+            }
+
+            // Register an HTTP trigger so users can start this workflow via HTTP.
+            if (registeredFunctions.Add(httpFunctionName))
+            {
+                this._logger.LogRegisteringWorkflowTrigger(workflow.Key, httpFunctionName, "http");
+                original.Add(FunctionMetadataFactory.CreateHttpTrigger(
+                    workflow.Key,
+                    $"workflows/{workflow.Key}/run",
+                    BuiltInFunctions.RunWorkflowOrchestrationHttpFunctionEntryPoint));
+            }
+
+            // Register a status endpoint if opted in via AddWorkflow(exposeStatusEndpoint: true).
+            if (this._options.IsStatusEndpointEnabled(workflow.Key))
+            {
+                string statusFunctionName = $"{BuiltInFunctions.HttpPrefix}{workflow.Key}-status";
+                if (registeredFunctions.Add(statusFunctionName))
+                {
+                    this._logger.LogRegisteringWorkflowTrigger(workflow.Key, statusFunctionName, "http-status");
+                    original.Add(FunctionMetadataFactory.CreateHttpTrigger(
+                        $"{workflow.Key}-status",
+                        $"workflows/{workflow.Key}/status/{{runId}}",
+                        BuiltInFunctions.GetWorkflowStatusHttpFunctionEntryPoint,
+                        methods: "\"get\""));
+                }
+            }
+
+            // Register a respond endpoint when the workflow contains RequestPort nodes.
+            bool hasRequestPorts = workflow.Value.ReflectExecutors().Values.Any(b => b is RequestPortBinding);
+            if (hasRequestPorts)
+            {
+                string respondFunctionName = $"{BuiltInFunctions.HttpPrefix}{workflow.Key}-respond";
+                if (registeredFunctions.Add(respondFunctionName))
+                {
+                    this._logger.LogRegisteringWorkflowTrigger(workflow.Key, respondFunctionName, "http-respond");
+                    original.Add(FunctionMetadataFactory.CreateHttpTrigger(
+                        $"{workflow.Key}-respond",
+                        $"workflows/{workflow.Key}/respond/{{runId}}",
+                        BuiltInFunctions.RespondToWorkflowHttpFunctionEntryPoint));
+                }
+            }
+
+            // Register activity or entity functions for each executor in the workflow.
+            // ReflectExecutors() returns all executors across the graph; no need to manually traverse edges.
+            foreach (KeyValuePair<string, ExecutorBinding> entry in workflow.Value.ReflectExecutors())
+            {
+                // Sub-workflow and RequestPort bindings use specialized dispatch, not activities.
+                if (entry.Value is SubworkflowBinding or RequestPortBinding)
+                {
+                    continue;
+                }
+
+                string executorName = WorkflowNamingHelper.GetExecutorName(entry.Key);
+
+                // AI agent executors are backed by durable entities; other executors use activity triggers.
+                if (entry.Value is AIAgentBinding)
+                {
+                    string entityName = AgentSessionId.ToEntityName(executorName);
+                    if (registeredFunctions.Add(entityName))
+                    {
+                        this._logger.LogRegisteringWorkflowTrigger(workflow.Key, entityName, "entity");
+                        original.Add(FunctionMetadataFactory.CreateEntityTrigger(executorName));
+                    }
+                }
+                else
+                {
+                    string functionName = WorkflowNamingHelper.ToOrchestrationFunctionName(executorName);
+                    if (registeredFunctions.Add(functionName))
+                    {
+                        this._logger.LogRegisteringWorkflowTrigger(workflow.Key, functionName, "activity");
+                        original.Add(FunctionMetadataFactory.CreateActivityTrigger(functionName));
+                    }
+                }
+            }
+        }
+
+        this._logger.LogTransformationComplete(original.Count - initialCount, original.Count);
+    }
+}
@@ -0,0 +1,51 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using Microsoft.Agents.AI.DurableTask.Workflows;
+using Microsoft.DurableTask;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+
+namespace Microsoft.Agents.AI.Hosting.AzureFunctions;
+
+/// <summary>
+/// A custom <see cref="ITaskOrchestrator"/> implementation that delegates workflow orchestration
+/// execution to the <see cref="DurableWorkflowRunner"/>.
+/// </summary>
+internal sealed class WorkflowOrchestrator : ITaskOrchestrator
+{
+    private readonly IServiceProvider _serviceProvider;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="WorkflowOrchestrator"/> class.
+    /// </summary>
+    /// <param name="serviceProvider">The service provider used to resolve workflow dependencies.</param>
+    public WorkflowOrchestrator(IServiceProvider serviceProvider)
+    {
+        this._serviceProvider = serviceProvider ?? throw new ArgumentNullException(nameof(serviceProvider));
+    }
+
+    /// <inheritdoc />
+    public Type InputType => typeof(DurableWorkflowInput<object>);
+
+    /// <inheritdoc />
+    public Type OutputType => typeof(DurableWorkflowResult);
+
+    /// <inheritdoc />
+    public async Task<object?> RunAsync(TaskOrchestrationContext context, object? input)
+    {
+        ArgumentNullException.ThrowIfNull(context);
+
+        DurableWorkflowRunner runner = this._serviceProvider.GetRequiredService<DurableWorkflowRunner>();
+        ILogger logger = context.CreateReplaySafeLogger(context.Name);
+
+        DurableWorkflowInput<object> workflowInput = input switch
+        {
+            DurableWorkflowInput<object> existing => existing,
+            _ => new DurableWorkflowInput<object> { Input = input! }
+        };
+
+        // ConfigureAwait(true) is required to preserve the orchestration context
+        // across awaits, which the Durable Task framework uses for replay.
+        return await runner.RunWorkflowOrchestrationAsync(context, workflowInput, logger).ConfigureAwait(true);
+    }
+}