Merge branch 'main' into feature-harness

dotnet/agent-framework-dotnet.slnx

@@ -169,10 +169,10 @@
     <Project Path="samples/02-agents/AgentsWithFoundry/Agent_Step25_ToolboxServerSideTools/Agent_Step25_ToolboxServerSideTools.csproj" />
   </Folder>
   <Folder Name="/Samples/02-agents/Evaluation/">
-    <Project Path="samples/02-agents/Evaluation/Evaluation_SimpleEval/Evaluation_SimpleEval.csproj" />
     <Project Path="samples/02-agents/Evaluation/Evaluation_CustomEvals/Evaluation_CustomEvals.csproj" />
     <Project Path="samples/02-agents/Evaluation/Evaluation_ExpectedOutputs/Evaluation_ExpectedOutputs.csproj" />
     <Project Path="samples/02-agents/Evaluation/Evaluation_Multimodal/Evaluation_Multimodal.csproj" />
+    <Project Path="samples/02-agents/Evaluation/Evaluation_SimpleEval/Evaluation_SimpleEval.csproj" />
   </Folder>
   <Folder Name="/Samples/02-agents/AgentWithMemory/">
     <File Path="samples/02-agents/AgentWithMemory/README.md" />
@@ -232,6 +232,7 @@
     <Project Path="samples/03-workflows/Declarative/HostedWorkflow/HostedWorkflow.csproj" />
     <Project Path="samples/03-workflows/Declarative/InputArguments/InputArguments.csproj" />
     <Project Path="samples/03-workflows/Declarative/InvokeFunctionTool/InvokeFunctionTool.csproj" />
+    <Project Path="samples/03-workflows/Declarative/InvokeHttpRequest/InvokeHttpRequest.csproj" />
     <Project Path="samples/03-workflows/Declarative/InvokeMcpTool/InvokeMcpTool.csproj" />
     <Project Path="samples/03-workflows/Declarative/Marketing/Marketing.csproj" />
     <Project Path="samples/03-workflows/Declarative/StudentTeacher/StudentTeacher.csproj" />
@@ -353,17 +354,17 @@
     <File Path="samples/02-agents/A2A/README.md" />
     <Project Path="samples/02-agents/A2A/A2AAgent_AsFunctionTools/A2AAgent_AsFunctionTools.csproj" />
     <Project Path="samples/02-agents/A2A/A2AAgent_PollingForTaskCompletion/A2AAgent_PollingForTaskCompletion.csproj" />
-    <Project Path="samples/02-agents/A2A/A2AAgent_StreamReconnection/A2AAgent_StreamReconnection.csproj" />
     <Project Path="samples/02-agents/A2A/A2AAgent_ProtocolSelection/A2AAgent_ProtocolSelection.csproj" />
+    <Project Path="samples/02-agents/A2A/A2AAgent_StreamReconnection/A2AAgent_StreamReconnection.csproj" />
   </Folder>  
   <Folder Name="/Samples/05-end-to-end/">
     <Project Path="samples/05-end-to-end/AgentWithPurview/AgentWithPurview.csproj" />
     <Project Path="samples/05-end-to-end/M365Agent/M365Agent.csproj" />
   </Folder>
   <Folder Name="/Samples/05-end-to-end/Evaluation/">
+    <Project Path="samples/05-end-to-end/Evaluation/Evaluation_ConversationSplits/Evaluation_ConversationSplits.csproj" />
     <Project Path="samples/05-end-to-end/Evaluation/Evaluation_FoundryQuality/Evaluation_FoundryQuality.csproj" />
     <Project Path="samples/05-end-to-end/Evaluation/Evaluation_MixedProviders/Evaluation_MixedProviders.csproj" />
-    <Project Path="samples/05-end-to-end/Evaluation/Evaluation_ConversationSplits/Evaluation_ConversationSplits.csproj" />
   </Folder>
   <Folder Name="/Samples/05-end-to-end/A2AClientServer/">
     <File Path="samples/05-end-to-end/A2AClientServer/README.md" />
@@ -549,8 +550,8 @@
     <Project Path="src/Microsoft.Agents.AI.Declarative/Microsoft.Agents.AI.Declarative.csproj" />
     <Project Path="src/Microsoft.Agents.AI.DevUI/Microsoft.Agents.AI.DevUI.csproj" />
     <Project Path="src/Microsoft.Agents.AI.DurableTask/Microsoft.Agents.AI.DurableTask.csproj" />
-    <Project Path="src/Microsoft.Agents.AI.Foundry/Microsoft.Agents.AI.Foundry.csproj" />
     <Project Path="src/Microsoft.Agents.AI.Foundry.Hosting/Microsoft.Agents.AI.Foundry.Hosting.csproj" />
+    <Project Path="src/Microsoft.Agents.AI.Foundry/Microsoft.Agents.AI.Foundry.csproj" />
     <Project Path="src/Microsoft.Agents.AI.GitHub.Copilot/Microsoft.Agents.AI.GitHub.Copilot.csproj" />
     <Project Path="src/Microsoft.Agents.AI.Hosting.A2A.AspNetCore/Microsoft.Agents.AI.Hosting.A2A.AspNetCore.csproj" />
     <Project Path="src/Microsoft.Agents.AI.Hosting.A2A/Microsoft.Agents.AI.Hosting.A2A.csproj" />

dotnet/samples/02-agents/AgentSkills/SubprocessScriptRunner.cs

@@ -5,16 +5,16 @@
 // This is provided for demonstration purposes only.
 
 using System.Diagnostics;
+using System.Text.Json;
 using Microsoft.Agents.AI;
-using Microsoft.Extensions.AI;
 
 /// <summary>
 /// Executes file-based skill scripts as local subprocesses.
 /// </summary>
 /// <remarks>
-/// This runner uses the script's absolute path, converts the arguments
-/// to CLI flags, and returns captured output. It is intended for
-/// demonstration purposes only.
+/// This runner uses the script's absolute path and converts the arguments
+/// to CLI arguments. When the LLM sends a JSON array, each element is used
+/// as a positional argument. It is intended for demonstration purposes only.
 /// </remarks>
 internal static class SubprocessScriptRunner
 {
@@ -24,7 +24,8 @@ internal static class SubprocessScriptRunner
     public static async Task<object?> RunAsync(
         AgentFileSkill skill,
         AgentFileSkillScript script,
-        AIFunctionArguments arguments,
+        JsonElement? arguments,
+        IServiceProvider? serviceProvider,
         CancellationToken cancellationToken)
     {
         if (!File.Exists(script.FullPath))
@@ -61,24 +62,27 @@ internal static class SubprocessScriptRunner
             startInfo.FileName = script.FullPath;
         }
 
-        if (arguments is not null)
+        if (arguments is { ValueKind: JsonValueKind.Array } json)
         {
-            foreach (var (key, value) in arguments)
+            // Positional CLI arguments
+            foreach (var element in json.EnumerateArray())
             {
-                if (value is bool boolValue)
+                if (element.ValueKind != JsonValueKind.String)
                 {
-                    if (boolValue)
-                    {
-                        startInfo.ArgumentList.Add(NormalizeKey(key));
-                    }
-                }
-                else if (value is not null)
-                {
-                    startInfo.ArgumentList.Add(NormalizeKey(key));
-                    startInfo.ArgumentList.Add(value.ToString()!);
+                    throw new InvalidOperationException(
+                        $"File-based skill scripts only accept string CLI arguments but received a JSON element of kind '{element.ValueKind}'. " +
+                        "All array elements must be JSON strings.");
                 }
+
+                startInfo.ArgumentList.Add(element.GetString()!);
             }
         }
+        else if (arguments is not null && arguments.Value.ValueKind != JsonValueKind.Null && arguments.Value.ValueKind != JsonValueKind.Undefined)
+        {
+            throw new InvalidOperationException(
+                $"Expected a JSON array of CLI arguments but received {arguments.Value.ValueKind}. " +
+                "File-based skill scripts expect positional arguments as a JSON array of strings.");
+        }
 
         Process? process = null;
         try
@@ -128,10 +132,4 @@ internal static class SubprocessScriptRunner
             process?.Dispose();
         }
     }
-
-    /// <summary>
-    /// Normalizes a parameter key to a consistent --flag format.
-    /// Models may return keys with or without leading dashes (e.g., "value" vs "--value").
-    /// </summary>
-    private static string NormalizeKey(string key) => "--" + key.TrimStart('-');
 }

dotnet/samples/03-workflows/Declarative/InvokeHttpRequest/InvokeHttpRequest.csproj

@@ -0,0 +1,38 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFrameworks>net10.0</TargetFrameworks>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <InjectIsExternalInitOnLegacy>true</InjectIsExternalInitOnLegacy>
+    <InjectSharedFoundryAgents>true</InjectSharedFoundryAgents>
+    <InjectSharedWorkflowsExecution>true</InjectSharedWorkflowsExecution>
+    <InjectSharedWorkflowsSettings>true</InjectSharedWorkflowsSettings>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.Configuration" />
+    <PackageReference Include="Microsoft.Extensions.Configuration.Binder" />
+    <PackageReference Include="Microsoft.Extensions.Configuration.EnvironmentVariables" />
+    <PackageReference Include="Microsoft.Extensions.Configuration.Json" />
+    <PackageReference Include="Microsoft.Extensions.Configuration.UserSecrets" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" />
+    <PackageReference Include="Microsoft.Extensions.Logging" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\..\..\src\Microsoft.Agents.AI.Workflows.Declarative\Microsoft.Agents.AI.Workflows.Declarative.csproj" />
+    <ProjectReference Include="..\..\..\..\src\Microsoft.Agents.AI.Workflows.Declarative.Foundry\Microsoft.Agents.AI.Workflows.Declarative.Foundry.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <None Include="InvokeHttpRequest.yaml">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </None>
+  </ItemGroup>
+
+</Project>

dotnet/samples/03-workflows/Declarative/InvokeHttpRequest/InvokeHttpRequest.yaml

@@ -0,0 +1,76 @@
+#
+# This workflow demonstrates using HttpRequestAction to call a REST API directly
+# from the workflow without going through an AI agent first.
+#
+# HttpRequestAction allows workflows to:
+# - Fetch data from external HTTP endpoints
+# - Store the parsed response in workflow variables for later use
+# - Add the response body to the conversation so a downstream agent can
+#   answer questions based on it
+#
+# This sample fetches public metadata for the dotnet/runtime repository from
+# the GitHub REST API (no authentication required) and uses an agent to
+# answer follow-up questions about it.
+#
+# Example input:
+# How many subscribers does the repository have?
+#
+kind: Workflow
+trigger:
+
+  kind: OnConversationStart
+  id: workflow_invoke_http_request_demo
+  actions:
+
+    # Capture the original user message for input to the follow-up agent.
+    - kind: SetVariable
+      id: set_user_message
+      variable: Local.InputMessage
+      value: =System.LastMessage
+
+    # Set the repository org/name used to form the request URL.
+    - kind: SetVariable
+      id: set_repo_name
+      variable: Local.RepoName
+      value: microsoft/agent-framework
+
+    # Invoke the GitHub repo API. The response body is parsed into Local.RepoInfo
+    # and also added to the conversation (via conversationId) so the agent below
+    # can answer questions based on it.
+    - kind: HttpRequestAction
+      id: fetch_repo_info
+      conversationId: =System.ConversationId
+      method: GET
+      url: =Concatenate("https://api.github.com/repos/", Local.RepoName)
+      headers:
+        Accept: application/vnd.github+json
+        User-Agent: agent-framework-sample
+      response: Local.RepoInfo
+
+    # Display a confirmation message showing key fields from the parsed response.
+    - kind: SendMessage
+      id: show_repo_summary
+      message: "Fetched repo: visibility={Local.RepoInfo.visibility}, description={Local.RepoInfo.description}"
+
+    # Use the agent to summarize the repo using the conversation context.
+    - kind: InvokeAzureAgent
+      id: summarize_repo
+      conversationId: =System.ConversationId
+      agent:
+        name: GitHubRepoInfoAgent
+      input:
+        messages: =UserMessage("Please provide a brief summary of this GitHub repository based on the data already in the conversation.")
+      output:
+        autoSend: true
+        messages: Local.AgentResponse
+
+    # Allow the user to ask follow-up questions about the repo in a loop.
+    - kind: InvokeAzureAgent
+      id: invoke_followup
+      conversationId: =System.ConversationId
+      agent:
+        name: GitHubRepoInfoAgent
+      input:
+        messages: =Local.InputMessage
+        externalLoop:
+          when: =Upper(System.LastMessage.Text) <> "EXIT"

dotnet/samples/03-workflows/Declarative/InvokeHttpRequest/Program.cs

@@ -0,0 +1,95 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using Azure.AI.Projects;
+using Azure.AI.Projects.Agents;
+using Azure.Identity;
+using Microsoft.Agents.AI.Workflows.Declarative;
+using Microsoft.Extensions.Configuration;
+using Shared.Foundry;
+using Shared.Workflows;
+
+namespace Demo.Workflows.Declarative.InvokeHttpRequest;
+
+/// <summary>
+/// Demonstrates a workflow that uses HttpRequestAction to call a REST API
+/// directly from the workflow.
+/// </summary>
+/// <remarks>
+/// <para>
+/// The HttpRequestAction allows workflows to issue HTTP requests and:
+/// </para>
+/// <list type="bullet">
+/// <item>Fetch data from external REST endpoints</item>
+/// <item>Store the parsed response in workflow variables</item>
+/// <item>Add the response body to the conversation so an agent can answer
+///       questions based on it</item>
+/// </list>
+/// <para>
+/// This sample fetches public metadata for the dotnet/runtime repository from
+/// the GitHub REST API (no authentication required) and uses a Foundry agent
+/// to answer follow-up questions about it. Type "EXIT" to end the conversation.
+/// </para>
+/// <para>
+/// See the README.md file in the parent folder (../README.md) for detailed
+/// information about the configuration required to run this sample.
+/// </para>
+/// </remarks>
+internal sealed class Program
+{
+    public static async Task Main(string[] args)
+    {
+        // Initialize configuration
+        IConfiguration configuration = Application.InitializeConfig();
+        Uri foundryEndpoint = new(configuration.GetValue(Application.Settings.FoundryEndpoint));
+
+        // Ensure sample agent exists in Foundry. The agent has no tools - it answers
+        // questions about the GitHub repository using only the JSON data that the
+        // HttpRequestAction adds to the conversation.
+        await CreateAgentAsync(foundryEndpoint, configuration);
+
+        // Get input from command line or console
+        string workflowInput = Application.GetInput(args);
+
+        // The default HttpRequestHandler is sufficient for this sample because the
+        // GitHub REST endpoint used here does not require authentication. For
+        // authenticated endpoints, supply a custom Func<HttpRequestInfo, ..., HttpClient?>
+        // to DefaultHttpRequestHandler so each request can be routed through a
+        // pre-configured (cached) HttpClient with the appropriate credentials.
+        await using DefaultHttpRequestHandler httpRequestHandler = new();
+
+        // Create the workflow factory with the HTTP request handler
+        WorkflowFactory workflowFactory = new("InvokeHttpRequest.yaml", foundryEndpoint)
+        {
+            HttpRequestHandler = httpRequestHandler
+        };
+
+        // Execute the workflow
+        WorkflowRunner runner = new() { UseJsonCheckpoints = true };
+        await runner.ExecuteAsync(workflowFactory.CreateWorkflow, workflowInput);
+    }
+
+    private static async Task CreateAgentAsync(Uri foundryEndpoint, IConfiguration configuration)
+    {
+        // WARNING: DefaultAzureCredential is convenient for development but requires careful consideration in production.
+        AIProjectClient aiProjectClient = new(foundryEndpoint, new DefaultAzureCredential());
+
+        await aiProjectClient.CreateAgentAsync(
+            agentName: "GitHubRepoInfoAgent",
+            agentDefinition: DefineAgent(configuration),
+            agentDescription: "Answers questions about a GitHub repository using HTTP response data in the conversation");
+    }
+
+    private static DeclarativeAgentDefinition DefineAgent(IConfiguration configuration)
+    {
+        return new DeclarativeAgentDefinition(configuration.GetValue(Application.Settings.FoundryModel))
+        {
+            Instructions =
+                """
+                Answer the user's questions about the GitHub repository using only the
+                JSON data already present in the conversation history.
+                If the answer is not contained in the conversation, say so plainly
+                rather than guessing. Be concise and helpful.
+                """
+        };
+    }
+}

dotnet/src/Microsoft.Agents.AI.Workflows.Declarative/DeclarativeWorkflowOptions.cs

@@ -26,6 +26,12 @@ public sealed class DeclarativeWorkflowOptions(ResponseAgentProvider agentProvid
     /// </summary>
     public IMcpToolHandler? McpToolHandler { get; init; }
 
+    /// <summary>
+    /// Gets or sets the HTTP request handler for executing <c>HttpRequestAction</c> actions within workflows.
+    /// If not set, HTTP request actions will fail with an appropriate error message.
+    /// </summary>
+    public IHttpRequestHandler? HttpRequestHandler { get; init; }
+
     /// <summary>
     /// Defines the configuration settings for the workflow.
     /// </summary>

dotnet/src/Microsoft.Agents.AI.Workflows.Declarative/DefaultHttpRequestHandler.cs

@@ -0,0 +1,289 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net.Http;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Microsoft.Agents.AI.Workflows.Declarative;
+
+/// <summary>
+/// Default implementation of <see cref="IHttpRequestHandler"/> built on <see cref="HttpClient"/>.
+/// </summary>
+/// <remarks>
+/// <para>
+/// This handler supports per-request authentication via an optional <c>httpClientProvider</c> callback that
+/// returns a pre-configured <see cref="HttpClient"/> for a given request (e.g. authenticated, custom handler).
+/// When the provider returns <see langword="null"/>, or no provider is supplied, a shared internal <see cref="HttpClient"/>
+/// is used.
+/// </para>
+/// <para>
+/// The handler applies the per-request <see cref="HttpRequestInfo.Timeout"/> using a linked <see cref="CancellationTokenSource"/>
+/// so it does not mutate <see cref="HttpClient.Timeout"/> on shared instances.
+/// </para>
+/// </remarks>
+public sealed class DefaultHttpRequestHandler : IHttpRequestHandler, IAsyncDisposable
+{
+    private readonly Func<HttpRequestInfo, CancellationToken, Task<HttpClient?>>? _httpClientProvider;
+    private readonly Lazy<HttpClient> _ownedHttpClient;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="DefaultHttpRequestHandler"/> class that uses an
+    /// internally owned <see cref="HttpClient"/> for all requests. The internal client is disposed
+    /// when <see cref="DisposeAsync"/> is called.
+    /// </summary>
+    public DefaultHttpRequestHandler()
+        : this(httpClientProvider: null)
+    {
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="DefaultHttpRequestHandler"/> class that uses the
+    /// supplied <see cref="HttpClient"/> for all requests.
+    /// </summary>
+    /// <param name="httpClient">
+    /// The <see cref="HttpClient"/> to use for all requests. The caller retains ownership of this
+    /// instance; it is not disposed by <see cref="DisposeAsync"/>.
+    /// </param>
+    /// <exception cref="ArgumentNullException"><paramref name="httpClient"/> is <see langword="null"/>.</exception>
+    public DefaultHttpRequestHandler(HttpClient httpClient)
+        : this(CreateSingleClientProvider(httpClient))
+    {
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="DefaultHttpRequestHandler"/> class that selects
+    /// an <see cref="HttpClient"/> per request via a caller-supplied callback — for example, to route
+    /// different URLs through differently authenticated clients.
+    /// </summary>
+    /// <param name="httpClientProvider">
+    /// An optional callback invoked for each request. The callback receives the <see cref="HttpRequestInfo"/>
+    /// and should return a pre-configured <see cref="HttpClient"/> (e.g. with authentication or a custom
+    /// transport). Return <see langword="null"/> to fall back to the handler's shared internal
+    /// <see cref="HttpClient"/>.
+    /// </param>
+    /// <remarks>
+    /// <para>
+    /// <b>Ownership</b>: the caller is solely responsible for the lifetime of clients returned by this
+    /// callback. <see cref="DefaultHttpRequestHandler"/> will <b>not</b> dispose provider-returned
+    /// clients; only the handler's internally owned fallback client is disposed by <see cref="DisposeAsync"/>.
+    /// </para>
+    /// <para>
+    /// <b>Reuse</b>: callers are expected to cache and reuse clients (for example, keyed by base URL or
+    /// auth scope) across requests. Returning a newly allocated <see cref="HttpClient"/> on every
+    /// invocation will leak sockets and handler resources.
+    /// </para>
+    /// </remarks>
+    public DefaultHttpRequestHandler(Func<HttpRequestInfo, CancellationToken, Task<HttpClient?>>? httpClientProvider)
+    {
+        this._httpClientProvider = httpClientProvider;
+        this._ownedHttpClient = new Lazy<HttpClient>(() => new HttpClient(), LazyThreadSafetyMode.ExecutionAndPublication);
+    }
+
+    private static Func<HttpRequestInfo, CancellationToken, Task<HttpClient?>> CreateSingleClientProvider(HttpClient httpClient)
+    {
+        if (httpClient is null)
+        {
+            throw new ArgumentNullException(nameof(httpClient));
+        }
+
+        return (_, _) => Task.FromResult<HttpClient?>(httpClient);
+    }
+
+    /// <inheritdoc/>
+    public async Task<HttpRequestResult> SendAsync(HttpRequestInfo request, CancellationToken cancellationToken = default)
+    {
+        if (request is null)
+        {
+            throw new ArgumentNullException(nameof(request));
+        }
+
+        if (string.IsNullOrWhiteSpace(request.Url))
+        {
+            throw new ArgumentException("Request URL must be provided.", nameof(request));
+        }
+
+        if (string.IsNullOrWhiteSpace(request.Method))
+        {
+            throw new ArgumentException("Request method must be provided.", nameof(request));
+        }
+
+        HttpClient? providedClient = null;
+        if (this._httpClientProvider is not null)
+        {
+            providedClient = await this._httpClientProvider(request, cancellationToken).ConfigureAwait(false);
+        }
+
+        HttpClient client = providedClient ?? this._ownedHttpClient.Value;
+
+        using HttpRequestMessage httpRequest = BuildHttpRequestMessage(request);
+
+        using CancellationTokenSource? timeoutCts = request.Timeout is { } timeout && timeout > TimeSpan.Zero
+            ? CancellationTokenSource.CreateLinkedTokenSource(cancellationToken)
+            : null;
+
+        timeoutCts?.CancelAfter(request.Timeout!.Value);
+
+        CancellationToken effectiveToken = timeoutCts?.Token ?? cancellationToken;
+
+        using HttpResponseMessage httpResponse = await client
+            .SendAsync(httpRequest, HttpCompletionOption.ResponseContentRead, effectiveToken)
+            .ConfigureAwait(false);
+
+        string? body = httpResponse.Content is null
+            ? null
+#if NET
+            : await httpResponse.Content.ReadAsStringAsync(effectiveToken).ConfigureAwait(false);
+#else
+            : await httpResponse.Content.ReadAsStringAsync().ConfigureAwait(false);
+#endif
+
+        Dictionary<string, IReadOnlyList<string>> headers = new(StringComparer.OrdinalIgnoreCase);
+        AppendHeaders(headers, httpResponse.Headers);
+        if (httpResponse.Content is not null)
+        {
+            AppendHeaders(headers, httpResponse.Content.Headers);
+        }
+
+        return new HttpRequestResult
+        {
+            StatusCode = (int)httpResponse.StatusCode,
+            IsSuccessStatusCode = httpResponse.IsSuccessStatusCode,
+            Body = body,
+            Headers = headers,
+        };
+    }
+
+    /// <inheritdoc/>
+    public ValueTask DisposeAsync()
+    {
+        if (this._ownedHttpClient.IsValueCreated)
+        {
+            this._ownedHttpClient.Value.Dispose();
+        }
+
+        return default;
+    }
+
+    private static HttpRequestMessage BuildHttpRequestMessage(HttpRequestInfo request)
+    {
+        HttpMethod method = ResolveMethod(request.Method);
+        string requestUri = ResolveRequestUri(request);
+        HttpRequestMessage httpRequest = new(method, requestUri);
+
+        if (request.Body is not null)
+        {
+            string contentType = string.IsNullOrWhiteSpace(request.BodyContentType)
+                ? "text/plain"
+                : request.BodyContentType!;
+
+            httpRequest.Content = new StringContent(request.Body, Encoding.UTF8);
+            // Replace the default content-type header (including charset) with the declared type.
+            httpRequest.Content.Headers.Remove("Content-Type");
+            httpRequest.Content.Headers.TryAddWithoutValidation("Content-Type", contentType);
+        }
+
+        if (request.Headers is not null)
+        {
+            foreach (KeyValuePair<string, string> header in request.Headers)
+            {
+                if (string.IsNullOrEmpty(header.Key))
+                {
+                    continue;
+                }
+
+                // Content-* headers belong on HttpContent; all others belong on the request.
+                if (header.Key.StartsWith("Content-", StringComparison.OrdinalIgnoreCase) && httpRequest.Content is not null)
+                {
+                    httpRequest.Content.Headers.Remove(header.Key);
+                    httpRequest.Content.Headers.TryAddWithoutValidation(header.Key, header.Value);
+                    continue;
+                }
+
+                if (!httpRequest.Headers.TryAddWithoutValidation(header.Key, header.Value))
+                {
+                    httpRequest.Content?.Headers.TryAddWithoutValidation(header.Key, header.Value);
+                }
+            }
+        }
+
+        return httpRequest;
+    }
+
+    private static HttpMethod ResolveMethod(string method)
+    {
+        string normalized = method.Trim().ToUpperInvariant();
+        return normalized switch
+        {
+            "GET" => HttpMethod.Get,
+            "POST" => HttpMethod.Post,
+            "PUT" => HttpMethod.Put,
+            "DELETE" => HttpMethod.Delete,
+#if NET
+            "PATCH" => HttpMethod.Patch,
+#else
+            "PATCH" => new HttpMethod("PATCH"),
+#endif
+            _ => new HttpMethod(normalized),
+        };
+    }
+
+    private static string ResolveRequestUri(HttpRequestInfo request)
+    {
+        string baseUrl = request.Url;
+        if (request.QueryParameters is null || request.QueryParameters.Count == 0)
+        {
+            return baseUrl;
+        }
+
+        StringBuilder queryBuilder = new();
+        foreach (KeyValuePair<string, string> parameter in request.QueryParameters)
+        {
+            if (string.IsNullOrEmpty(parameter.Key))
+            {
+                continue;
+            }
+
+            if (queryBuilder.Length > 0)
+            {
+                queryBuilder.Append('&');
+            }
+
+            queryBuilder.Append(Uri.EscapeDataString(parameter.Key))
+                .Append('=')
+                .Append(Uri.EscapeDataString(parameter.Value ?? string.Empty));
+        }
+
+        if (queryBuilder.Length == 0)
+        {
+            return baseUrl;
+        }
+
+        char separator = baseUrl.Contains('?') ? '&' : '?';
+        return string.Concat(baseUrl, separator.ToString(), queryBuilder.ToString());
+    }
+
+    private static void AppendHeaders(
+        Dictionary<string, IReadOnlyList<string>> target,
+        System.Net.Http.Headers.HttpHeaders source)
+    {
+        foreach (KeyValuePair<string, IEnumerable<string>> header in source)
+        {
+            string[] values = header.Value.ToArray();
+
+            if (target.TryGetValue(header.Key, out IReadOnlyList<string>? existing))
+            {
+                List<string> combined = new(existing);
+                combined.AddRange(values);
+                target[header.Key] = combined;
+            }
+            else
+            {
+                target[header.Key] = values;
+            }
+        }
+    }
+}

dotnet/src/Microsoft.Agents.AI.Workflows.Declarative/Extensions/ChatMessageExtensions.cs

@@ -16,6 +16,60 @@ internal static class ChatMessageExtensions
     public static RecordValue ToRecord(this ChatMessage message) =>
         FormulaValue.NewRecordFromFields(message.GetMessageFields());
 
+    /// <summary>
+    /// Merges the user-authored <paramref name="input"/> with the round-tripped
+    /// <paramref name="inputMessage"/> returned by <c>AgentProvider.CreateMessageAsync</c>
+    /// to produce the value stored in <c>System.LastMessage</c>.
+    /// </summary>
+    /// <remarks>
+    /// The agent service often strips or alters <see cref="TextContent"/> on round-trip,
+    /// while replacing inline media (<see cref="DataContent"/>, <see cref="UriContent"/>)
+    /// with server-side references (typically <see cref="HostedFileContent"/>).
+    /// We want both: the original text (so <c>=System.LastMessage.Text</c> works) and
+    /// the server's media references (so subsequent actions don't re-upload large blobs).
+    /// <para>
+    /// Strategy: keep <paramref name="inputMessage"/> as the base — it has the server-generated
+    /// <see cref="ChatMessage.MessageId"/> and any provider-augmented metadata, and is forward-
+    /// compatible with new properties added on <see cref="ChatMessage"/> in the abstractions
+    /// layer. Only the <see cref="ChatMessage.Contents"/> list is mutated to substitute
+    /// original <see cref="TextContent"/> items in place (and append any extras the round-trip
+    /// dropped). Non-text content items returned by the service are left untouched so
+    /// server-side references survive.
+    /// </para>
+    /// </remarks>
+    public static ChatMessage MergeForLastMessage(this ChatMessage input, ChatMessage? inputMessage)
+    {
+        if (inputMessage is null)
+        {
+            return input;
+        }
+
+        // Build a queue of the original text items, in order. Fall back to ChatMessage.Text
+        // if the input has no explicit TextContent entries.
+        Queue<TextContent> originalTexts = new(input.Contents.OfType<TextContent>());
+        if (originalTexts.Count == 0 && !string.IsNullOrEmpty(input.Text))
+        {
+            originalTexts.Enqueue(new TextContent(input.Text));
+        }
+
+        // Replace TextContent items in inputMessage.Contents with the originals, in order.
+        for (int i = 0; i < inputMessage.Contents.Count && originalTexts.Count > 0; i++)
+        {
+            if (inputMessage.Contents[i] is TextContent)
+            {
+                inputMessage.Contents[i] = originalTexts.Dequeue();
+            }
+        }
+
+        // Append any remaining original text items that the round-trip dropped entirely.
+        while (originalTexts.Count > 0)
+        {
+            inputMessage.Contents.Add(originalTexts.Dequeue());
+        }
+
+        return inputMessage;
+    }
+
     public static TableValue ToTable(this IEnumerable<ChatMessage> messages) =>
         FormulaValue.NewTable(TypeSchema.Message.RecordType, messages.Select(message => message.ToRecord()));
 

dotnet/src/Microsoft.Agents.AI.Workflows.Declarative/IHttpRequestHandler.cs

@@ -0,0 +1,103 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Microsoft.Agents.AI.Workflows.Declarative;
+
+/// <summary>
+/// Defines the contract for executing HTTP requests emitted by <c>HttpRequestAction</c> within declarative workflows.
+/// </summary>
+/// <remarks>
+/// This interface allows the HTTP request dispatch to be abstracted, enabling different implementations
+/// for local development, hosted workflows, authenticated scenarios, and testing.
+/// </remarks>
+public interface IHttpRequestHandler
+{
+    /// <summary>
+    /// Sends an HTTP request and returns the response.
+    /// </summary>
+    /// <param name="request">The HTTP request to send.</param>
+    /// <param name="cancellationToken">A token to observe cancellation.</param>
+    /// <returns>The <see cref="HttpRequestResult"/> describing the HTTP response.</returns>
+    Task<HttpRequestResult> SendAsync(
+        HttpRequestInfo request,
+        CancellationToken cancellationToken = default);
+}
+
+/// <summary>
+/// Describes an HTTP request to be sent by an <see cref="IHttpRequestHandler"/>.
+/// </summary>
+[SuppressMessage("Design", "CA1056:URI-like properties should not be strings", Justification = "URL is carried as a string to preserve the declarative expression result and to avoid forcing handler implementations to construct a Uri eagerly.")]
+public sealed class HttpRequestInfo
+{
+    /// <summary>
+    /// Gets the HTTP method to use (GET, POST, PUT, PATCH, DELETE).
+    /// </summary>
+    public string Method { get; init; } = "GET";
+
+    /// <summary>
+    /// Gets the absolute URL to send the request to.
+    /// </summary>
+    public string Url { get; init; } = string.Empty;
+
+    /// <summary>
+    /// Gets the headers to include on the request, excluding the <c>Content-Type</c> header (which is supplied via <see cref="BodyContentType"/>).
+    /// </summary>
+    public IReadOnlyDictionary<string, string>? Headers { get; init; }
+
+    /// <summary>
+    /// Gets the <c>Content-Type</c> of the request body, or <see langword="null"/> if no body is sent.
+    /// </summary>
+    public string? BodyContentType { get; init; }
+
+    /// <summary>
+    /// Gets the serialized request body, or <see langword="null"/> if no body is sent.
+    /// </summary>
+    public string? Body { get; init; }
+
+    /// <summary>
+    /// Gets the maximum amount of time to wait for the request to complete, or <see langword="null"/> to use the handler default.
+    /// </summary>
+    public TimeSpan? Timeout { get; init; }
+
+    /// <summary>
+    /// Gets the query parameters to append to the request URL, with values already formatted as strings.
+    /// </summary>
+    public IReadOnlyDictionary<string, string>? QueryParameters { get; init; }
+
+    /// <summary>
+    /// Gets the name of the declared remote connection, or <see langword="null"/> if no connection is declared.
+    /// This maps to the Foundry project connection Id and is only used when running in foundry service.
+    /// </summary>
+    public string? ConnectionName { get; init; }
+}
+
+/// <summary>
+/// Represents the result of an HTTP request executed by an <see cref="IHttpRequestHandler"/>.
+/// </summary>
+public sealed class HttpRequestResult
+{
+    /// <summary>
+    /// Gets the HTTP status code returned by the server.
+    /// </summary>
+    public int StatusCode { get; init; }
+
+    /// <summary>
+    /// Gets a value indicating whether the status code is in the range 200-299.
+    /// </summary>
+    public bool IsSuccessStatusCode { get; init; }
+
+    /// <summary>
+    /// Gets the response body, or <see langword="null"/> if no body was returned.
+    /// </summary>
+    public string? Body { get; init; }
+
+    /// <summary>
+    /// Gets the response headers keyed by header name. Each header may have multiple values.
+    /// </summary>
+    public IReadOnlyDictionary<string, IReadOnlyList<string>>? Headers { get; init; }
+}

dotnet/src/Microsoft.Agents.AI.Workflows.Declarative/Interpreter/DeclarativeWorkflowExecutor.cs

@@ -43,7 +43,11 @@ internal sealed class DeclarativeWorkflowExecutor<TInput>(
         await declarativeContext.QueueConversationUpdateAsync(conversationId, isExternal: true, cancellationToken).ConfigureAwait(false);
 
         ChatMessage inputMessage = await options.AgentProvider.CreateMessageAsync(conversationId, input, cancellationToken).ConfigureAwait(false);
-        await declarativeContext.SetLastMessageAsync(inputMessage).ConfigureAwait(false);
+
+        // Use the original input for System.LastMessage to ensure Text is preserved (the
+        // service may strip text on round-trip), but substitute server-side media references
+        // (e.g., HostedFileContent) so subsequent actions don't re-upload large blobs.
+        await declarativeContext.SetLastMessageAsync(input.MergeForLastMessage(inputMessage)).ConfigureAwait(false);
 
         await context.SendResultMessageAsync(this.Id, cancellationToken).ConfigureAwait(false);
     }

dotnet/src/Microsoft.Agents.AI.Workflows.Declarative/Interpreter/WorkflowActionVisitor.cs

@@ -529,6 +529,18 @@ internal sealed class WorkflowActionVisitor : DialogActionVisitor
         this._workflowModel.AddNode(new DelegateActionExecutor(postId, this._workflowState, action.CompleteAsync), action.ParentId);
     }
 
+    protected override void Visit(HttpRequestAction item)
+    {
+        this.Trace(item);
+
+        if (this._workflowOptions.HttpRequestHandler is null)
+        {
+            throw new DeclarativeModelException("HTTP request handler not configured. Set HttpRequestHandler in DeclarativeWorkflowOptions to use HttpRequestAction actions.");
+        }
+
+        this.ContinueWith(new HttpRequestExecutor(item, this._workflowOptions.HttpRequestHandler, this._workflowOptions.AgentProvider, this._workflowState));
+    }
+
     #region Not supported
 
     protected override void Visit(AnswerQuestionWithAI item) => this.NotSupported(item);
@@ -573,8 +585,6 @@ internal sealed class WorkflowActionVisitor : DialogActionVisitor
 
     protected override void Visit(GetConversationMembers item) => this.NotSupported(item);
 
-    protected override void Visit(HttpRequestAction item) => this.NotSupported(item);
-
     protected override void Visit(RecognizeIntent item) => this.NotSupported(item);
 
     protected override void Visit(TransferConversation item) => this.NotSupported(item);

dotnet/src/Microsoft.Agents.AI.Workflows.Declarative/Kit/RootExecutor.cs

@@ -58,7 +58,6 @@ public abstract class RootExecutor<TInput> : Executor<TInput>, IResettableExecut
     public override async ValueTask HandleAsync(TInput message, IWorkflowContext context, CancellationToken cancellationToken)
     {
         DeclarativeWorkflowContext declarativeContext = new(context, this._state);
-        await this.ExecuteAsync(message, declarativeContext, cancellationToken).ConfigureAwait(false);
 
         ChatMessage input = (this._inputTransform ?? DefaultInputTransform).Invoke(message);
 
@@ -69,7 +68,13 @@ public abstract class RootExecutor<TInput> : Executor<TInput>, IResettableExecut
         await declarativeContext.QueueConversationUpdateAsync(this._conversationId, isExternal: true, cancellationToken).ConfigureAwait(false);
 
         ChatMessage inputMessage = await this._agentProvider.CreateMessageAsync(this._conversationId, input, cancellationToken).ConfigureAwait(false);
-        await declarativeContext.SetLastMessageAsync(inputMessage).ConfigureAwait(false);
+
+        // Use the original input for System.LastMessage to ensure Text is preserved (the
+        // service may strip text on round-trip), but substitute server-side media references
+        // (e.g., HostedFileContent) so subsequent actions don't re-upload large blobs.
+        await declarativeContext.SetLastMessageAsync(input.MergeForLastMessage(inputMessage)).ConfigureAwait(false);
+
+        await this.ExecuteAsync(message, declarativeContext, cancellationToken).ConfigureAwait(false);
 
         await declarativeContext.SendResultMessageAsync(this.Id, cancellationToken).ConfigureAwait(false);
     }

dotnet/src/Microsoft.Agents.AI.Workflows.Declarative/ObjectModel/HttpRequestExecutor.cs

@@ -0,0 +1,346 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using System.Collections.Generic;
+using System.Text.Json;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Agents.AI.Workflows.Declarative.Extensions;
+using Microsoft.Agents.AI.Workflows.Declarative.Interpreter;
+using Microsoft.Agents.AI.Workflows.Declarative.Kit;
+using Microsoft.Agents.AI.Workflows.Declarative.PowerFx;
+using Microsoft.Agents.ObjectModel;
+using Microsoft.Extensions.AI;
+using Microsoft.PowerFx.Types;
+using Microsoft.Shared.Diagnostics;
+
+namespace Microsoft.Agents.AI.Workflows.Declarative.ObjectModel;
+
+/// <summary>
+/// Executor for the <see cref="HttpRequestAction"/> action.
+/// Dispatches the request through the configured <see cref="IHttpRequestHandler"/> and assigns
+/// the response body and headers to the declared property paths.
+/// </summary>
+internal sealed class HttpRequestExecutor(
+    HttpRequestAction model,
+    IHttpRequestHandler httpRequestHandler,
+    ResponseAgentProvider agentProvider,
+    WorkflowFormulaState state) :
+    DeclarativeActionExecutor<HttpRequestAction>(model, state)
+{
+    /// <inheritdoc/>
+    protected override async ValueTask<object?> ExecuteAsync(IWorkflowContext context, CancellationToken cancellationToken = default)
+    {
+        string method = this.GetMethod();
+        string url = this.GetUrl();
+        Dictionary<string, string>? headers = this.GetHeaders();
+        Dictionary<string, string>? queryParameters = this.GetQueryParameters();
+        (string? body, string? contentType) = this.GetBody();
+        TimeSpan? timeout = this.GetTimeout();
+        string? conversationId = this.GetConversationId();
+        string? connectionName = this.GetConnectionName();
+
+        HttpRequestInfo requestInfo = new()
+        {
+            Method = method,
+            Url = url,
+            Headers = headers,
+            QueryParameters = queryParameters,
+            Body = body,
+            BodyContentType = contentType,
+            Timeout = timeout,
+            ConnectionName = connectionName,
+        };
+
+        HttpRequestResult result;
+        try
+        {
+            result = await httpRequestHandler.SendAsync(requestInfo, cancellationToken).ConfigureAwait(false);
+        }
+        catch (OperationCanceledException) when (!cancellationToken.IsCancellationRequested)
+        {
+            throw this.Exception($"HTTP request to '{url}' timed out.");
+        }
+        catch (Exception exception) when (exception is not DeclarativeActionException)
+        {
+            throw this.Exception($"HTTP request to '{url}' failed: {exception.Message}", exception);
+        }
+
+        if (result.IsSuccessStatusCode)
+        {
+            await this.AssignResponseAsync(context, result.Body).ConfigureAwait(false);
+            await this.AssignResponseHeadersAsync(context, result.Headers).ConfigureAwait(false);
+            await this.AddResponseToConversationAsync(conversationId, result.Body, cancellationToken).ConfigureAwait(false);
+            return default;
+        }
+
+        // Non-success status code - throw.
+        // Also publish response headers for diagnostic purposes.
+        await this.AssignResponseHeadersAsync(context, result.Headers).ConfigureAwait(false);
+
+        string bodyPreview = FormatBodyForDiagnostics(result.Body);
+        string message = bodyPreview.Length == 0
+            ? $"HTTP request to '{url}' failed with status code {result.StatusCode}."
+            : $"HTTP request to '{url}' failed with status code {result.StatusCode}. Body: '{bodyPreview}'";
+
+        throw this.Exception(message);
+    }
+
+    // Response bodies can echo secrets (tokens, PII) and may be very large (multi-MB HTML error pages).
+    // Exception messages are often logged and persisted, so we clip the body to bound both exposure
+    // and message size. Full bodies are still available via the success path (assigned to Response).
+    private const int MaxBodyDiagnosticLength = 256;
+    private const string BodyTruncationSuffix = " \u2026 [truncated]";
+
+    private static string FormatBodyForDiagnostics(string? body)
+    {
+        if (string.IsNullOrEmpty(body))
+        {
+            return string.Empty;
+        }
+
+        int sourceLen = body!.Length;
+        bool truncated = sourceLen > MaxBodyDiagnosticLength;
+        int copyLen = truncated ? MaxBodyDiagnosticLength : sourceLen;
+        int finalLen = copyLen + (truncated ? BodyTruncationSuffix.Length : 0);
+
+        // Size the buffer for the final string so we only allocate once for the chars
+        // and once for the string itself. For a 10 KB error body we touch 256 chars instead of 10,000.
+        char[] buffer = new char[finalLen];
+        for (int i = 0; i < copyLen; i++)
+        {
+            char c = body[i];
+            buffer[i] = c is '\r' or '\n' or '\t' ? ' ' : c;
+        }
+
+        if (truncated)
+        {
+            BodyTruncationSuffix.CopyTo(0, buffer, copyLen, BodyTruncationSuffix.Length);
+        }
+
+        return new string(buffer);
+    }
+
+    private async ValueTask AddResponseToConversationAsync(string? conversationId, string? responseBody, CancellationToken cancellationToken)
+    {
+        if (conversationId is null || string.IsNullOrEmpty(responseBody))
+        {
+            return;
+        }
+
+        ChatMessage message = new(ChatRole.Assistant, responseBody);
+        await agentProvider.CreateMessageAsync(conversationId, message, cancellationToken).ConfigureAwait(false);
+    }
+
+    private async ValueTask AssignResponseAsync(IWorkflowContext context, string? responseBody)
+    {
+        if (this.Model.Response is not { Path: { } responsePath })
+        {
+            return;
+        }
+
+        await this.AssignAsync(responsePath, ParseResponseBody(responseBody), context).ConfigureAwait(false);
+    }
+
+    private async ValueTask AssignResponseHeadersAsync(IWorkflowContext context, IReadOnlyDictionary<string, IReadOnlyList<string>>? responseHeaders)
+    {
+        if (this.Model.ResponseHeaders is not { Path: { } headersPath })
+        {
+            return;
+        }
+
+        if (responseHeaders is null || responseHeaders.Count == 0)
+        {
+            await this.AssignAsync(headersPath, FormulaValue.NewBlank(), context).ConfigureAwait(false);
+            return;
+        }
+
+        // Flatten multi-value headers by joining with commas (standard HTTP header folding).
+        Dictionary<string, object?> flattened = new(StringComparer.OrdinalIgnoreCase);
+        foreach (KeyValuePair<string, IReadOnlyList<string>> header in responseHeaders)
+        {
+            flattened[header.Key] = string.Join(",", header.Value);
+        }
+
+        await this.AssignAsync(headersPath, flattened.ToFormula(), context).ConfigureAwait(false);
+    }
+
+    private static FormulaValue ParseResponseBody(string? responseBody)
+    {
+        if (string.IsNullOrEmpty(responseBody))
+        {
+            return FormulaValue.NewBlank();
+        }
+
+        // Attempt to parse as JSON so records/tables are exposed naturally to the workflow.
+        try
+        {
+            using JsonDocument jsonDocument = JsonDocument.Parse(responseBody);
+
+            object? parsedValue = jsonDocument.RootElement.ValueKind switch
+            {
+                JsonValueKind.Object => jsonDocument.ParseRecord(VariableType.RecordType),
+                JsonValueKind.Array => jsonDocument.ParseList(jsonDocument.RootElement.GetListTypeFromJson()),
+                JsonValueKind.String => jsonDocument.RootElement.GetString(),
+                JsonValueKind.Number => jsonDocument.RootElement.TryGetInt64(out long l)
+                    ? l
+                    : jsonDocument.RootElement.GetDouble(),
+                JsonValueKind.True => true,
+                JsonValueKind.False => false,
+                JsonValueKind.Null => null,
+                _ => responseBody,
+            };
+
+            return parsedValue.ToFormula();
+        }
+        catch (JsonException)
+        {
+            // Not valid JSON — return the raw string.
+            return FormulaValue.New(responseBody);
+        }
+    }
+
+    private string GetMethod()
+    {
+        EnumExpression<HttpMethodTypeWrapper>? methodExpression = this.Model.Method;
+        if (methodExpression is null)
+        {
+            return "GET";
+        }
+
+        HttpMethodTypeWrapper wrapper = this.Evaluator.GetValue(methodExpression).Value;
+        return !string.IsNullOrEmpty(wrapper.UnknownValue) ? wrapper.UnknownValue! : wrapper.Value.ToString().ToUpperInvariant();
+    }
+
+    private string GetUrl() =>
+        this.Evaluator.GetValue(
+            Throw.IfNull(
+                this.Model.Url,
+                $"{nameof(this.Model)}.{nameof(this.Model.Url)}")).Value;
+
+    private Dictionary<string, string>? GetHeaders()
+    {
+        if (this.Model.Headers is null || this.Model.Headers.Count == 0)
+        {
+            return null;
+        }
+
+        Dictionary<string, string> result = new(StringComparer.OrdinalIgnoreCase);
+        foreach (KeyValuePair<string, StringExpression> header in this.Model.Headers)
+        {
+            string value = this.Evaluator.GetValue(header.Value).Value;
+            if (!string.IsNullOrEmpty(value))
+            {
+                result[header.Key] = value;
+            }
+        }
+
+        return result.Count == 0 ? null : result;
+    }
+
+    private (string? Body, string? ContentType) GetBody()
+    {
+        switch (this.Model.Body)
+        {
+            case null:
+            case NoRequestContent:
+                return (null, null);
+
+            case JsonRequestContent jsonContent when jsonContent.Content is not null:
+            {
+                FormulaValue formula = this.Evaluator.GetValue(jsonContent.Content).Value.ToFormula();
+                string json = formula.ToJson().ToJsonString();
+                return (json, "application/json");
+            }
+
+            case RawRequestContent rawContent:
+            {
+                string? content = rawContent.Content is null
+                        ? null
+                        : this.Evaluator.GetValue(rawContent.Content).Value;
+
+                string? contentType = rawContent.ContentType is null
+                        ? null
+                        : this.Evaluator.GetValue(rawContent.ContentType).Value;
+
+                return (content, string.IsNullOrEmpty(contentType) ? null : contentType);
+            }
+
+            default:
+                return (null, null);
+        }
+    }
+
+    private TimeSpan? GetTimeout()
+    {
+        if (this.Model.RequestTimeoutInMilliseconds is null || this.Model.RequestTimeoutInMillisecondsIsDefaultValue)
+        {
+            return null;
+        }
+
+        long value = this.Evaluator.GetValue(this.Model.RequestTimeoutInMilliseconds).Value;
+        return value > 0 ? TimeSpan.FromMilliseconds(value) : null;
+    }
+
+    private Dictionary<string, string>? GetQueryParameters()
+    {
+        if (this.Model.QueryParameters is null || this.Model.QueryParameters.Count == 0)
+        {
+            return null;
+        }
+
+        Dictionary<string, string> result = new(StringComparer.Ordinal);
+        foreach (KeyValuePair<string, ValueExpression> parameter in this.Model.QueryParameters)
+        {
+            if (string.IsNullOrEmpty(parameter.Key) || parameter.Value is null)
+            {
+                continue;
+            }
+
+            object? rawValue = this.Evaluator.GetValue(parameter.Value).Value.ToObject();
+            string? formatted = FormatQueryValue(rawValue);
+            if (formatted is not null)
+            {
+                result[parameter.Key] = formatted;
+            }
+        }
+
+        return result.Count == 0 ? null : result;
+    }
+
+    private static string? FormatQueryValue(object? value) =>
+        value switch
+        {
+            null => null,
+            string s => s,
+            bool b => b ? "true" : "false",
+            IFormattable formattable => formattable.ToString(null, System.Globalization.CultureInfo.InvariantCulture),
+            _ => value.ToString(),
+        };
+
+    private string? GetConversationId()
+    {
+        if (this.Model.ConversationId is null)
+        {
+            return null;
+        }
+
+        string value = this.Evaluator.GetValue(this.Model.ConversationId).Value;
+        return value.Length == 0 ? null : value;
+    }
+
+    private string? GetConnectionName()
+    {
+        RemoteConnection? connection = this.Model.Connection;
+        if (connection is null)
+        {
+            return null;
+        }
+
+        string? name = connection.Name is null
+            ? null
+            : this.Evaluator.GetValue(connection.Name).Value;
+
+        return string.IsNullOrEmpty(name) ? null : name;
+    }
+}

dotnet/src/Microsoft.Agents.AI/CompatibilitySuppressions.xml

@@ -1,6 +1,20 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!-- https://learn.microsoft.com/dotnet/fundamentals/package-validation/diagnostic-ids -->
 <Suppressions xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Microsoft.Agents.AI.AgentFileSkillScriptRunner.BeginInvoke(Microsoft.Agents.AI.AgentFileSkill,Microsoft.Agents.AI.AgentFileSkillScript,Microsoft.Extensions.AI.AIFunctionArguments,System.Threading.CancellationToken,System.AsyncCallback,System.Object)</Target>
+    <Left>lib/net10.0/Microsoft.Agents.AI.dll</Left>
+    <Right>lib/net10.0/Microsoft.Agents.AI.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Microsoft.Agents.AI.AgentFileSkillScriptRunner.Invoke(Microsoft.Agents.AI.AgentFileSkill,Microsoft.Agents.AI.AgentFileSkillScript,Microsoft.Extensions.AI.AIFunctionArguments,System.Threading.CancellationToken)</Target>
+    <Left>lib/net10.0/Microsoft.Agents.AI.dll</Left>
+    <Right>lib/net10.0/Microsoft.Agents.AI.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>M:Microsoft.Agents.AI.AgentInlineSkill.#ctor(Microsoft.Agents.AI.AgentSkillFrontmatter,System.String)</Target>
@@ -29,6 +43,13 @@
     <Right>lib/net10.0/Microsoft.Agents.AI.dll</Right>
     <IsBaselineSuppression>true</IsBaselineSuppression>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Microsoft.Agents.AI.AgentSkillScript.RunAsync(Microsoft.Agents.AI.AgentSkill,Microsoft.Extensions.AI.AIFunctionArguments,System.Threading.CancellationToken)</Target>
+    <Left>lib/net10.0/Microsoft.Agents.AI.dll</Left>
+    <Right>lib/net10.0/Microsoft.Agents.AI.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>M:Microsoft.Agents.AI.AgentSkillsProvider.#ctor(Microsoft.Agents.AI.AgentInlineSkill[])</Target>
@@ -43,6 +64,20 @@
     <Right>lib/net10.0/Microsoft.Agents.AI.dll</Right>
     <IsBaselineSuppression>true</IsBaselineSuppression>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Microsoft.Agents.AI.AgentFileSkillScriptRunner.BeginInvoke(Microsoft.Agents.AI.AgentFileSkill,Microsoft.Agents.AI.AgentFileSkillScript,Microsoft.Extensions.AI.AIFunctionArguments,System.Threading.CancellationToken,System.AsyncCallback,System.Object)</Target>
+    <Left>lib/net472/Microsoft.Agents.AI.dll</Left>
+    <Right>lib/net472/Microsoft.Agents.AI.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Microsoft.Agents.AI.AgentFileSkillScriptRunner.Invoke(Microsoft.Agents.AI.AgentFileSkill,Microsoft.Agents.AI.AgentFileSkillScript,Microsoft.Extensions.AI.AIFunctionArguments,System.Threading.CancellationToken)</Target>
+    <Left>lib/net472/Microsoft.Agents.AI.dll</Left>
+    <Right>lib/net472/Microsoft.Agents.AI.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>M:Microsoft.Agents.AI.AgentInlineSkill.#ctor(Microsoft.Agents.AI.AgentSkillFrontmatter,System.String)</Target>
@@ -71,6 +106,13 @@
     <Right>lib/net472/Microsoft.Agents.AI.dll</Right>
     <IsBaselineSuppression>true</IsBaselineSuppression>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Microsoft.Agents.AI.AgentSkillScript.RunAsync(Microsoft.Agents.AI.AgentSkill,Microsoft.Extensions.AI.AIFunctionArguments,System.Threading.CancellationToken)</Target>
+    <Left>lib/net472/Microsoft.Agents.AI.dll</Left>
+    <Right>lib/net472/Microsoft.Agents.AI.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>M:Microsoft.Agents.AI.AgentSkillsProvider.#ctor(Microsoft.Agents.AI.AgentInlineSkill[])</Target>
@@ -85,6 +127,20 @@
     <Right>lib/net472/Microsoft.Agents.AI.dll</Right>
     <IsBaselineSuppression>true</IsBaselineSuppression>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Microsoft.Agents.AI.AgentFileSkillScriptRunner.BeginInvoke(Microsoft.Agents.AI.AgentFileSkill,Microsoft.Agents.AI.AgentFileSkillScript,Microsoft.Extensions.AI.AIFunctionArguments,System.Threading.CancellationToken,System.AsyncCallback,System.Object)</Target>
+    <Left>lib/net8.0/Microsoft.Agents.AI.dll</Left>
+    <Right>lib/net8.0/Microsoft.Agents.AI.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Microsoft.Agents.AI.AgentFileSkillScriptRunner.Invoke(Microsoft.Agents.AI.AgentFileSkill,Microsoft.Agents.AI.AgentFileSkillScript,Microsoft.Extensions.AI.AIFunctionArguments,System.Threading.CancellationToken)</Target>
+    <Left>lib/net8.0/Microsoft.Agents.AI.dll</Left>
+    <Right>lib/net8.0/Microsoft.Agents.AI.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>M:Microsoft.Agents.AI.AgentInlineSkill.#ctor(Microsoft.Agents.AI.AgentSkillFrontmatter,System.String)</Target>
@@ -113,6 +169,13 @@
     <Right>lib/net8.0/Microsoft.Agents.AI.dll</Right>
     <IsBaselineSuppression>true</IsBaselineSuppression>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Microsoft.Agents.AI.AgentSkillScript.RunAsync(Microsoft.Agents.AI.AgentSkill,Microsoft.Extensions.AI.AIFunctionArguments,System.Threading.CancellationToken)</Target>
+    <Left>lib/net8.0/Microsoft.Agents.AI.dll</Left>
+    <Right>lib/net8.0/Microsoft.Agents.AI.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>M:Microsoft.Agents.AI.AgentSkillsProvider.#ctor(Microsoft.Agents.AI.AgentInlineSkill[])</Target>
@@ -127,6 +190,20 @@
     <Right>lib/net8.0/Microsoft.Agents.AI.dll</Right>
     <IsBaselineSuppression>true</IsBaselineSuppression>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Microsoft.Agents.AI.AgentFileSkillScriptRunner.BeginInvoke(Microsoft.Agents.AI.AgentFileSkill,Microsoft.Agents.AI.AgentFileSkillScript,Microsoft.Extensions.AI.AIFunctionArguments,System.Threading.CancellationToken,System.AsyncCallback,System.Object)</Target>
+    <Left>lib/net9.0/Microsoft.Agents.AI.dll</Left>
+    <Right>lib/net9.0/Microsoft.Agents.AI.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Microsoft.Agents.AI.AgentFileSkillScriptRunner.Invoke(Microsoft.Agents.AI.AgentFileSkill,Microsoft.Agents.AI.AgentFileSkillScript,Microsoft.Extensions.AI.AIFunctionArguments,System.Threading.CancellationToken)</Target>
+    <Left>lib/net9.0/Microsoft.Agents.AI.dll</Left>
+    <Right>lib/net9.0/Microsoft.Agents.AI.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>M:Microsoft.Agents.AI.AgentInlineSkill.#ctor(Microsoft.Agents.AI.AgentSkillFrontmatter,System.String)</Target>
@@ -155,6 +232,13 @@
     <Right>lib/net9.0/Microsoft.Agents.AI.dll</Right>
     <IsBaselineSuppression>true</IsBaselineSuppression>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Microsoft.Agents.AI.AgentSkillScript.RunAsync(Microsoft.Agents.AI.AgentSkill,Microsoft.Extensions.AI.AIFunctionArguments,System.Threading.CancellationToken)</Target>
+    <Left>lib/net9.0/Microsoft.Agents.AI.dll</Left>
+    <Right>lib/net9.0/Microsoft.Agents.AI.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>M:Microsoft.Agents.AI.AgentSkillsProvider.#ctor(Microsoft.Agents.AI.AgentInlineSkill[])</Target>
@@ -169,6 +253,20 @@
     <Right>lib/net9.0/Microsoft.Agents.AI.dll</Right>
     <IsBaselineSuppression>true</IsBaselineSuppression>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Microsoft.Agents.AI.AgentFileSkillScriptRunner.BeginInvoke(Microsoft.Agents.AI.AgentFileSkill,Microsoft.Agents.AI.AgentFileSkillScript,Microsoft.Extensions.AI.AIFunctionArguments,System.Threading.CancellationToken,System.AsyncCallback,System.Object)</Target>
+    <Left>lib/netstandard2.0/Microsoft.Agents.AI.dll</Left>
+    <Right>lib/netstandard2.0/Microsoft.Agents.AI.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Microsoft.Agents.AI.AgentFileSkillScriptRunner.Invoke(Microsoft.Agents.AI.AgentFileSkill,Microsoft.Agents.AI.AgentFileSkillScript,Microsoft.Extensions.AI.AIFunctionArguments,System.Threading.CancellationToken)</Target>
+    <Left>lib/netstandard2.0/Microsoft.Agents.AI.dll</Left>
+    <Right>lib/netstandard2.0/Microsoft.Agents.AI.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>M:Microsoft.Agents.AI.AgentInlineSkill.#ctor(Microsoft.Agents.AI.AgentSkillFrontmatter,System.String)</Target>
@@ -197,6 +295,13 @@
     <Right>lib/netstandard2.0/Microsoft.Agents.AI.dll</Right>
     <IsBaselineSuppression>true</IsBaselineSuppression>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Microsoft.Agents.AI.AgentSkillScript.RunAsync(Microsoft.Agents.AI.AgentSkill,Microsoft.Extensions.AI.AIFunctionArguments,System.Threading.CancellationToken)</Target>
+    <Left>lib/netstandard2.0/Microsoft.Agents.AI.dll</Left>
+    <Right>lib/netstandard2.0/Microsoft.Agents.AI.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>M:Microsoft.Agents.AI.AgentSkillsProvider.#ctor(Microsoft.Agents.AI.AgentInlineSkill[])</Target>
@@ -211,4 +316,39 @@
     <Right>lib/netstandard2.0/Microsoft.Agents.AI.dll</Right>
     <IsBaselineSuppression>true</IsBaselineSuppression>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0005</DiagnosticId>
+    <Target>M:Microsoft.Agents.AI.AgentSkillScript.RunAsync(Microsoft.Agents.AI.AgentSkill,System.Nullable{System.Text.Json.JsonElement},System.IServiceProvider,System.Threading.CancellationToken)</Target>
+    <Left>lib/net10.0/Microsoft.Agents.AI.dll</Left>
+    <Right>lib/net10.0/Microsoft.Agents.AI.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0005</DiagnosticId>
+    <Target>M:Microsoft.Agents.AI.AgentSkillScript.RunAsync(Microsoft.Agents.AI.AgentSkill,System.Nullable{System.Text.Json.JsonElement},System.IServiceProvider,System.Threading.CancellationToken)</Target>
+    <Left>lib/net472/Microsoft.Agents.AI.dll</Left>
+    <Right>lib/net472/Microsoft.Agents.AI.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0005</DiagnosticId>
+    <Target>M:Microsoft.Agents.AI.AgentSkillScript.RunAsync(Microsoft.Agents.AI.AgentSkill,System.Nullable{System.Text.Json.JsonElement},System.IServiceProvider,System.Threading.CancellationToken)</Target>
+    <Left>lib/net8.0/Microsoft.Agents.AI.dll</Left>
+    <Right>lib/net8.0/Microsoft.Agents.AI.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0005</DiagnosticId>
+    <Target>M:Microsoft.Agents.AI.AgentSkillScript.RunAsync(Microsoft.Agents.AI.AgentSkill,System.Nullable{System.Text.Json.JsonElement},System.IServiceProvider,System.Threading.CancellationToken)</Target>
+    <Left>lib/net9.0/Microsoft.Agents.AI.dll</Left>
+    <Right>lib/net9.0/Microsoft.Agents.AI.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0005</DiagnosticId>
+    <Target>M:Microsoft.Agents.AI.AgentSkillScript.RunAsync(Microsoft.Agents.AI.AgentSkill,System.Nullable{System.Text.Json.JsonElement},System.IServiceProvider,System.Threading.CancellationToken)</Target>
+    <Left>lib/netstandard2.0/Microsoft.Agents.AI.dll</Left>
+    <Right>lib/netstandard2.0/Microsoft.Agents.AI.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
 </Suppressions>

dotnet/src/Microsoft.Agents.AI/Skills/AgentSkill.cs

@@ -35,7 +35,8 @@ public abstract class AgentSkill
     /// Gets the full skill content.
     /// </summary>
     /// <remarks>
-    /// For file-based skills this is the raw SKILL.md file content.
+    /// For file-based skills this is the raw SKILL.md file content, optionally
+    /// augmented with a synthesized scripts block when scripts are present.
     /// For code-defined skills this is a synthesized XML document
     /// containing name, description, and body (instructions, resources, scripts).
     /// </remarks>

dotnet/src/Microsoft.Agents.AI/Skills/AgentSkillScript.cs

@@ -1,10 +1,10 @@
 // Copyright (c) Microsoft. All rights reserved.
 
+using System;
 using System.Diagnostics.CodeAnalysis;
 using System.Text.Json;
 using System.Threading;
 using System.Threading.Tasks;
-using Microsoft.Extensions.AI;
 using Microsoft.Shared.DiagnosticIds;
 using Microsoft.Shared.Diagnostics;
 
@@ -46,8 +46,9 @@ public abstract class AgentSkillScript
     /// Runs the script with the given arguments.
     /// </summary>
     /// <param name="skill">The skill that owns this script.</param>
-    /// <param name="arguments">Arguments for script execution.</param>
+    /// <param name="arguments">Raw JSON arguments for script execution, preserving the original format (object or array) sent by the caller.</param>
+    /// <param name="serviceProvider">Optional service provider for dependency injection.</param>
     /// <param name="cancellationToken">Cancellation token.</param>
     /// <returns>The script execution result.</returns>
-    public abstract Task<object?> RunAsync(AgentSkill skill, AIFunctionArguments arguments, CancellationToken cancellationToken = default);
+    public abstract Task<object?> RunAsync(AgentSkill skill, JsonElement? arguments, IServiceProvider? serviceProvider, CancellationToken cancellationToken = default);
 }

dotnet/src/Microsoft.Agents.AI/Skills/AgentSkillsProvider.cs

@@ -6,6 +6,7 @@ using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Security;
 using System.Text;
+using System.Text.Json;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Extensions.AI;
@@ -243,7 +244,7 @@ public sealed partial class AgentSkillsProvider : AIContextProvider
         }
 
         AIFunction scriptFunction = AIFunctionFactory.Create(
-            (string skillName, string scriptName, IDictionary<string, object?>? arguments = null, IServiceProvider? serviceProvider = null, CancellationToken cancellationToken = default) =>
+            (string skillName, string scriptName, JsonElement? arguments = null, IServiceProvider? serviceProvider = null, CancellationToken cancellationToken = default) =>
                 this.RunSkillScriptAsync(skills, skillName, scriptName, arguments, serviceProvider, cancellationToken),
             name: "run_skill_script",
             description: "Runs a script associated with a skill.");
@@ -340,7 +341,7 @@ public sealed partial class AgentSkillsProvider : AIContextProvider
         }
     }
 
-    private async Task<object?> RunSkillScriptAsync(IList<AgentSkill> skills, string skillName, string scriptName, IDictionary<string, object?>? arguments = null, IServiceProvider? serviceProvider = null, CancellationToken cancellationToken = default)
+    private async Task<object?> RunSkillScriptAsync(IList<AgentSkill> skills, string skillName, string scriptName, JsonElement? arguments = null, IServiceProvider? serviceProvider = null, CancellationToken cancellationToken = default)
     {
         if (string.IsNullOrWhiteSpace(skillName))
         {
@@ -366,7 +367,7 @@ public sealed partial class AgentSkillsProvider : AIContextProvider
 
         try
         {
-            return await script.RunAsync(skill, new AIFunctionArguments(arguments) { Services = serviceProvider }, cancellationToken).ConfigureAwait(false);
+            return await script.RunAsync(skill, arguments, serviceProvider, cancellationToken).ConfigureAwait(false);
         }
         catch (Exception ex)
         {

dotnet/src/Microsoft.Agents.AI/Skills/File/AgentFileSkill.cs

@@ -15,6 +15,8 @@ public sealed class AgentFileSkill : AgentSkill
 {
     private readonly IReadOnlyList<AgentSkillResource> _resources;
     private readonly IReadOnlyList<AgentSkillScript> _scripts;
+    private readonly string _originalContent;
+    private string? _content;
 
     /// <summary>
     /// Initializes a new instance of the <see cref="AgentFileSkill"/> class.
@@ -32,7 +34,7 @@ public sealed class AgentFileSkill : AgentSkill
         IReadOnlyList<AgentSkillScript>? scripts = null)
     {
         this.Frontmatter = Throw.IfNull(frontmatter);
-        this.Content = Throw.IfNull(content);
+        this._originalContent = Throw.IfNull(content);
         this.Path = Throw.IfNullOrWhitespace(path);
         this._resources = resources ?? [];
         this._scripts = scripts ?? [];
@@ -42,7 +44,18 @@ public sealed class AgentFileSkill : AgentSkill
     public override AgentSkillFrontmatter Frontmatter { get; }
 
     /// <inheritdoc/>
-    public override string Content { get; }
+    /// <remarks>
+    /// Returns the raw SKILL.md content. When the skill has scripts, a
+    /// <c>&lt;scripts&gt;&lt;script name="..."&gt;&lt;parameters_schema&gt;...&lt;/parameters_schema&gt;&lt;/script&gt;&lt;/scripts&gt;</c>
+    /// block is appended with a per-script entry describing the expected argument format.
+    /// The result is cached after the first access.
+    /// </remarks>
+    public override string Content
+    {
+        get => this._content ??= this._scripts is { Count: > 0 }
+            ? this._originalContent + AgentInlineSkillContentBuilder.BuildScriptsBlock(this._scripts)
+            : this._originalContent;
+    }
 
     /// <summary>
     /// Gets the directory path where the skill was discovered.

dotnet/src/Microsoft.Agents.AI/Skills/File/AgentFileSkillScript.cs

@@ -2,9 +2,9 @@
 
 using System;
 using System.Diagnostics.CodeAnalysis;
+using System.Text.Json;
 using System.Threading;
 using System.Threading.Tasks;
-using Microsoft.Extensions.AI;
 using Microsoft.Shared.DiagnosticIds;
 using Microsoft.Shared.Diagnostics;
 
@@ -16,6 +16,11 @@ namespace Microsoft.Agents.AI;
 [Experimental(DiagnosticIds.Experiments.AgentsAIExperiments)]
 public sealed class AgentFileSkillScript : AgentSkillScript
 {
+    /// <summary>
+    /// Cached JSON schema element describing the expected argument format: a string array of CLI arguments.
+    /// </summary>
+    private static readonly JsonElement s_defaultSchema = CreateDefaultSchema();
+
     private readonly AgentFileSkillScriptRunner? _runner;
 
     /// <summary>
@@ -37,7 +42,14 @@ public sealed class AgentFileSkillScript : AgentSkillScript
     public string FullPath { get; }
 
     /// <inheritdoc/>
-    public override async Task<object?> RunAsync(AgentSkill skill, AIFunctionArguments arguments, CancellationToken cancellationToken = default)
+    /// <remarks>
+    /// Returns a fixed schema describing a string array of CLI arguments:
+    /// <c>{"type":"array","items":{"type":"string"}}</c>.
+    /// </remarks>
+    public override JsonElement? ParametersSchema => s_defaultSchema;
+
+    /// <inheritdoc/>
+    public override async Task<object?> RunAsync(AgentSkill skill, JsonElement? arguments, IServiceProvider? serviceProvider, CancellationToken cancellationToken = default)
     {
         if (skill is not AgentFileSkill fileSkill)
         {
@@ -51,6 +63,12 @@ public sealed class AgentFileSkillScript : AgentSkillScript
                 $"Supply a script runner when constructing {nameof(AgentFileSkillsSource)} to enable script execution.");
         }
 
-        return await this._runner(fileSkill, this, arguments, cancellationToken).ConfigureAwait(false);
+        return await this._runner(fileSkill, this, arguments, serviceProvider, cancellationToken).ConfigureAwait(false);
+    }
+
+    private static JsonElement CreateDefaultSchema()
+    {
+        using JsonDocument document = JsonDocument.Parse("""{"type":"array","items":{"type":"string"}}""");
+        return document.RootElement.Clone();
     }
 }

dotnet/src/Microsoft.Agents.AI/Skills/File/AgentFileSkillScriptRunner.cs

@@ -1,9 +1,10 @@
 // Copyright (c) Microsoft. All rights reserved.
 
+using System;
 using System.Diagnostics.CodeAnalysis;
+using System.Text.Json;
 using System.Threading;
 using System.Threading.Tasks;
-using Microsoft.Extensions.AI;
 using Microsoft.Shared.DiagnosticIds;
 
 namespace Microsoft.Agents.AI;
@@ -13,15 +14,19 @@ namespace Microsoft.Agents.AI;
 /// </summary>
 /// <remarks>
 /// Implementations determine the execution strategy (e.g., local subprocess, hosted code execution environment).
+/// The <paramref name="arguments"/> parameter preserves the raw JSON sent by the caller, in the shape
+/// described by <see cref="AgentFileSkillScript.ParametersSchema"/>.
 /// </remarks>
 /// <param name="skill">The skill that owns the script.</param>
 /// <param name="script">The file-based script to run.</param>
-/// <param name="arguments">Optional arguments for the script, provided by the agent/LLM.</param>
+/// <param name="arguments">Raw JSON arguments for the script, in the shape described by <see cref="AgentFileSkillScript.ParametersSchema"/>.</param>
+/// <param name="serviceProvider">Optional service provider for dependency injection.</param>
 /// <param name="cancellationToken">Cancellation token.</param>
 /// <returns>The script execution result.</returns>
 [Experimental(DiagnosticIds.Experiments.AgentsAIExperiments)]
 public delegate Task<object?> AgentFileSkillScriptRunner(
     AgentFileSkill skill,
     AgentFileSkillScript script,
-    AIFunctionArguments arguments,
+    JsonElement? arguments,
+    IServiceProvider? serviceProvider,
     CancellationToken cancellationToken);

dotnet/src/Microsoft.Agents.AI/Skills/Programmatic/AgentInlineSkillContentBuilder.cs

@@ -59,36 +59,60 @@ internal static class AgentInlineSkillContentBuilder
 
         if (scripts is { Count: > 0 })
         {
-            sb.Append("\n\n<scripts>\n");
-            foreach (var script in scripts)
-            {
-                var parametersSchema = script.ParametersSchema;
-
-                if (script.Description is null && parametersSchema is null)
-                {
-                    sb.Append($"  <script name=\"{EscapeXmlString(script.Name)}\"/>\n");
-                }
-                else
-                {
-                    sb.Append(script.Description is not null
-                        ? $"  <script name=\"{EscapeXmlString(script.Name)}\" description=\"{EscapeXmlString(script.Description)}\">\n"
-                        : $"  <script name=\"{EscapeXmlString(script.Name)}\">\n");
-
-                    if (parametersSchema is not null)
-                    {
-                        sb.Append($"    <parameters_schema>{EscapeXmlString(parametersSchema.Value.GetRawText(), preserveQuotes: true)}</parameters_schema>\n");
-                    }
-
-                    sb.Append("  </script>\n");
-                }
-            }
-
-            sb.Append("</scripts>");
+            sb.Append('\n');
+            sb.Append(BuildScriptsBlock(scripts));
         }
 
         return sb.ToString();
     }
 
+    /// <summary>
+    /// Builds a <c>&lt;scripts&gt;...&lt;/scripts&gt;</c> XML block for the given scripts.
+    /// Each script is emitted as a <c>&lt;script name="..."&gt;</c> element with optional
+    /// <c>description</c> attribute and <c>&lt;parameters_schema&gt;</c> child element.
+    /// </summary>
+    /// <param name="scripts">The scripts to include in the block.</param>
+    /// <returns>An XML string starting with <c>\n&lt;scripts&gt;</c>, or an empty string if the list is empty.</returns>
+    public static string BuildScriptsBlock(IReadOnlyList<AgentSkillScript> scripts)
+    {
+        _ = Throw.IfNull(scripts);
+
+        if (scripts.Count == 0)
+        {
+            return string.Empty;
+        }
+
+        var sb = new StringBuilder();
+        sb.Append("\n<scripts>\n");
+
+        foreach (var script in scripts)
+        {
+            var parametersSchema = script.ParametersSchema;
+
+            if (script.Description is null && parametersSchema is null)
+            {
+                sb.Append($"  <script name=\"{EscapeXmlString(script.Name)}\"/>\n");
+            }
+            else
+            {
+                sb.Append(script.Description is not null
+                    ? $"  <script name=\"{EscapeXmlString(script.Name)}\" description=\"{EscapeXmlString(script.Description)}\">\n"
+                    : $"  <script name=\"{EscapeXmlString(script.Name)}\">\n");
+
+                if (parametersSchema is not null)
+                {
+                    sb.Append($"    <parameters_schema>{EscapeXmlString(parametersSchema.Value.GetRawText(), preserveQuotes: true)}</parameters_schema>\n");
+                }
+
+                sb.Append("  </script>\n");
+            }
+        }
+
+        sb.Append("</scripts>");
+
+        return sb.ToString();
+    }
+
     /// <summary>
     /// Escapes XML special characters: always escapes <c>&amp;</c>, <c>&lt;</c>, <c>&gt;</c>,
     /// <c>&quot;</c>, and <c>&apos;</c>. When <paramref name="preserveQuotes"/> is <see langword="true"/>,

dotnet/src/Microsoft.Agents.AI/Skills/Programmatic/AgentInlineSkillScript.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft. All rights reserved.
 
 using System;
+using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Reflection;
 using System.Text.Json;
@@ -67,8 +68,42 @@ internal sealed class AgentInlineSkillScript : AgentSkillScript
     public override JsonElement? ParametersSchema => this._function.JsonSchema;
 
     /// <inheritdoc/>
-    public override async Task<object?> RunAsync(AgentSkill skill, AIFunctionArguments arguments, CancellationToken cancellationToken = default)
+    public override async Task<object?> RunAsync(AgentSkill skill, JsonElement? arguments, IServiceProvider? serviceProvider, CancellationToken cancellationToken = default)
     {
-        return await this._function.InvokeAsync(arguments, cancellationToken).ConfigureAwait(false);
+        var funcArgs = ConvertToFunctionArguments(arguments);
+        funcArgs.Services = serviceProvider;
+
+        return await this._function.InvokeAsync(funcArgs, cancellationToken).ConfigureAwait(false);
+    }
+
+    /// <summary>
+    /// Converts a raw <see cref="JsonElement"/> to <see cref="AIFunctionArguments"/> for delegate invocation.
+    /// </summary>
+    /// <exception cref="InvalidOperationException">
+    /// Thrown when <paramref name="arguments"/> is provided but is not a JSON object.
+    /// Inline skill scripts expect arguments as a JSON object whose properties map to the delegate's parameters.
+    /// </exception>
+    private static AIFunctionArguments ConvertToFunctionArguments(JsonElement? arguments)
+    {
+        if (arguments is null ||
+            arguments.Value.ValueKind == JsonValueKind.Null ||
+            arguments.Value.ValueKind == JsonValueKind.Undefined)
+        {
+            return [];
+        }
+
+        if (arguments.Value.ValueKind != JsonValueKind.Object)
+        {
+            throw new InvalidOperationException(
+                $"Inline skill scripts expect arguments as a JSON object but received a JSON element of kind '{arguments.Value.ValueKind}'.");
+        }
+
+        var dict = new Dictionary<string, object?>();
+        foreach (var property in arguments.Value.EnumerateObject())
+        {
+            dict[property.Name] = property.Value;
+        }
+
+        return new AIFunctionArguments(dict);
     }
 }

dotnet/src/Shared/Workflows/Execution/WorkflowFactory.cs

@@ -25,6 +25,9 @@ internal sealed class WorkflowFactory(string workflowFile, Uri foundryEndpoint)
     // Assign to provide MCP tool capabilities
     public IMcpToolHandler? McpToolHandler { get; init; }
 
+    // Assign to enable HttpRequestAction support
+    public IHttpRequestHandler? HttpRequestHandler { get; init; }
+
     /// <summary>
     /// Create the workflow from the declarative YAML.  Includes definition of the
     /// <see cref="DeclarativeWorkflowOptions" /> and the associated <see cref="ResponseAgentProvider"/>.
@@ -46,6 +49,7 @@ internal sealed class WorkflowFactory(string workflowFile, Uri foundryEndpoint)
                 ConversationId = this.ConversationId,
                 LoggerFactory = this.LoggerFactory,
                 McpToolHandler = this.McpToolHandler,
+                HttpRequestHandler = this.HttpRequestHandler,
             };
 
         string workflowPath = Path.Combine(AppContext.BaseDirectory, workflowFile);

dotnet/src/Shared/Workflows/Execution/WorkflowRunner.cs

@@ -162,7 +162,10 @@ internal sealed class WorkflowRunner
 
                 case RequestInfoEvent requestInfo:
                     Debug.WriteLine($"REQUEST #{requestInfo.Request.RequestId}");
-                    externalResponse = requestInfo.Request;
+                    if (response is null || !string.Equals(requestInfo.Request.RequestId, response.RequestId, StringComparison.Ordinal))
+                    {
+                        externalResponse = requestInfo.Request;
+                    }
                     break;
 
                 case ConversationUpdateEvent invokeEvent:

dotnet/tests/Microsoft.Agents.AI.UnitTests/AgentSkills/AgentClassSkillTests.cs

@@ -8,7 +8,6 @@ using System.Reflection;
 using System.Text.Json;
 using System.Threading;
 using System.Threading.Tasks;
-using Microsoft.Extensions.AI;
 using Microsoft.Extensions.DependencyInjection;
 
 namespace Microsoft.Agents.AI.UnitTests.AgentSkills;
@@ -128,8 +127,9 @@ public sealed class AgentClassSkillTests
         // Act — script with custom type deserialization
         var script = skill.Scripts![0];
         var inputJson = JsonSerializer.SerializeToElement(new LookupRequest { Query = "test", MaxResults = 5 }, jso);
-        var args = new AIFunctionArguments { ["request"] = inputJson };
-        var scriptResult = await script.RunAsync(skill, args, CancellationToken.None);
+        using var argsDoc = JsonDocument.Parse($$"""{ "request": {{inputJson.GetRawText()}} }""");
+        var args = argsDoc.RootElement;
+        var scriptResult = await script.RunAsync(skill, args, null, CancellationToken.None);
 
         // Assert
         Assert.NotNull(scriptResult);
@@ -173,12 +173,14 @@ public sealed class AgentClassSkillTests
 
         // Act & Assert — static method
         var doWorkScript = skill.Scripts!.First(s => s.Name == "do-work");
-        var doWorkResult = await doWorkScript.RunAsync(skill, new AIFunctionArguments { ["input"] = "hello" }, CancellationToken.None);
+        using var doWorkDoc = JsonDocument.Parse("""{"input":"hello"}""");
+        var doWorkResult = await doWorkScript.RunAsync(skill, doWorkDoc.RootElement, null, CancellationToken.None);
         Assert.Equal("HELLO", doWorkResult?.ToString());
 
         // Act & Assert — instance method
         var appendScript = skill.Scripts!.First(s => s.Name == "append");
-        var appendResult = await appendScript.RunAsync(skill, new AIFunctionArguments { ["input"] = "test" }, CancellationToken.None);
+        using var appendDoc = JsonDocument.Parse("""{"input":"test"}""");
+        var appendResult = await appendScript.RunAsync(skill, appendDoc.RootElement, null, CancellationToken.None);
         Assert.Equal("test-suffix", appendResult?.ToString());
     }
 
@@ -367,7 +369,7 @@ public sealed class AgentClassSkillTests
         // Act & Assert — all scripts produce values
         foreach (var script in skill.Scripts!)
         {
-            var result = await script.RunAsync(skill, new AIFunctionArguments(), CancellationToken.None);
+            var result = await script.RunAsync(skill, null, null, CancellationToken.None);
             Assert.NotNull(result);
         }
     }
@@ -382,8 +384,9 @@ public sealed class AgentClassSkillTests
         // Act & Assert — script with custom JSO
         var script = skill.Scripts![0];
         var inputJson = JsonSerializer.SerializeToElement(new LookupRequest { Query = "test", MaxResults = 3 }, jso);
-        var args = new AIFunctionArguments { ["request"] = inputJson };
-        var scriptResult = await script.RunAsync(skill, args, CancellationToken.None);
+        using var argsDoc = JsonDocument.Parse($$"""{ "request": {{inputJson.GetRawText()}} }""");
+        var args = argsDoc.RootElement;
+        var scriptResult = await script.RunAsync(skill, args, null, CancellationToken.None);
         Assert.NotNull(scriptResult);
         Assert.Contains("test", scriptResult!.ToString()!);
         Assert.Contains("3", scriptResult!.ToString()!);
@@ -497,8 +500,9 @@ public sealed class AgentClassSkillTests
         var script = skill.Scripts!.First(s => s.Name == "Lookup");
         var jso = SkillTestJsonContext.Default.Options;
         var inputJson = JsonSerializer.SerializeToElement(new LookupRequest { Query = "fallback", MaxResults = 7 }, jso);
-        var args = new AIFunctionArguments { ["request"] = inputJson };
-        var result = await script.RunAsync(skill, args, CancellationToken.None);
+        using var argsDoc = JsonDocument.Parse($$"""{ "request": {{inputJson.GetRawText()}} }""");
+        var args = argsDoc.RootElement;
+        var result = await script.RunAsync(skill, args, null, CancellationToken.None);
 
         // Assert
         Assert.NotNull(result);
@@ -531,8 +535,9 @@ public sealed class AgentClassSkillTests
         var script = skill.Scripts!.First(s => s.Name == "Lookup");
         var jso = SkillTestJsonContext.Default.Options;
         var inputJson = JsonSerializer.SerializeToElement(new LookupRequest { Query = "explicit", MaxResults = 2 }, jso);
-        var args = new AIFunctionArguments { ["request"] = inputJson };
-        var result = await script.RunAsync(skill, args, CancellationToken.None);
+        using var argsDoc = JsonDocument.Parse($$"""{ "request": {{inputJson.GetRawText()}} }""");
+        var args = argsDoc.RootElement;
+        var result = await script.RunAsync(skill, args, null, CancellationToken.None);
 
         // Assert
         Assert.NotNull(result);

dotnet/tests/Microsoft.Agents.AI.UnitTests/AgentSkills/AgentFileSkillScriptTests.cs

@@ -1,9 +1,9 @@
 // Copyright (c) Microsoft. All rights reserved.
 
 using System;
+using System.Text.Json;
 using System.Threading;
 using System.Threading.Tasks;
-using Microsoft.Extensions.AI;
 
 namespace Microsoft.Agents.AI.UnitTests.AgentSkills;
 
@@ -16,13 +16,13 @@ public sealed class AgentFileSkillScriptTests
     public async Task RunAsync_SkillIsNotAgentFileSkill_ThrowsInvalidOperationExceptionAsync()
     {
         // Arrange
-        static Task<object?> RunnerAsync(AgentFileSkill s, AgentFileSkillScript sc, AIFunctionArguments a, CancellationToken ct) => Task.FromResult<object?>("result");
+        static Task<object?> RunnerAsync(AgentFileSkill s, AgentFileSkillScript sc, JsonElement? a, IServiceProvider? sp, CancellationToken ct) => Task.FromResult<object?>("result");
         var script = CreateScript("test-script", "/path/to/script.py", RunnerAsync);
         var nonFileSkill = new TestAgentSkill("my-skill", "A skill", "Instructions.");
 
         // Act & Assert
         await Assert.ThrowsAsync<InvalidOperationException>(
-            () => script.RunAsync(nonFileSkill, new AIFunctionArguments(), CancellationToken.None));
+            () => script.RunAsync(nonFileSkill, null, null, CancellationToken.None));
     }
 
     [Fact]
@@ -30,7 +30,7 @@ public sealed class AgentFileSkillScriptTests
     {
         // Arrange
         var runnerCalled = false;
-        Task<object?> runnerAsync(AgentFileSkill skill, AgentFileSkillScript scriptArg, AIFunctionArguments args, CancellationToken ct)
+        Task<object?> runnerAsync(AgentFileSkill skill, AgentFileSkillScript scriptArg, JsonElement? args, IServiceProvider? sp, CancellationToken ct)
         {
             runnerCalled = true;
             return Task.FromResult<object?>("executed");
@@ -42,7 +42,7 @@ public sealed class AgentFileSkillScriptTests
             "/skills/my-skill");
 
         // Act
-        var result = await script.RunAsync(fileSkill, new AIFunctionArguments(), CancellationToken.None);
+        var result = await script.RunAsync(fileSkill, null, null, CancellationToken.None);
 
         // Assert
         Assert.True(runnerCalled);
@@ -55,7 +55,7 @@ public sealed class AgentFileSkillScriptTests
         // Arrange
         AgentFileSkill? capturedSkill = null;
         AgentFileSkillScript? capturedScript = null;
-        Task<object?> runnerAsync(AgentFileSkill skill, AgentFileSkillScript scriptArg, AIFunctionArguments args, CancellationToken ct)
+        Task<object?> runnerAsync(AgentFileSkill skill, AgentFileSkillScript scriptArg, JsonElement? args, IServiceProvider? sp, CancellationToken ct)
         {
             capturedSkill = skill;
             capturedScript = scriptArg;
@@ -68,7 +68,7 @@ public sealed class AgentFileSkillScriptTests
             "/skills/owner-skill");
 
         // Act
-        await script.RunAsync(fileSkill, new AIFunctionArguments(), CancellationToken.None);
+        await script.RunAsync(fileSkill, null, null, CancellationToken.None);
 
         // Assert
         Assert.Same(fileSkill, capturedSkill);
@@ -79,7 +79,7 @@ public sealed class AgentFileSkillScriptTests
     public void Script_HasCorrectNameAndPath()
     {
         // Arrange & Act
-        static Task<object?> RunnerAsync(AgentFileSkill s, AgentFileSkillScript sc, AIFunctionArguments a, CancellationToken ct) => Task.FromResult<object?>(null);
+        static Task<object?> RunnerAsync(AgentFileSkill s, AgentFileSkillScript sc, JsonElement? a, IServiceProvider? sp, CancellationToken ct) => Task.FromResult<object?>(null);
         var script = CreateScript("my-script", "/path/to/my-script.py", RunnerAsync);
 
         // Assert
@@ -87,10 +87,173 @@ public sealed class AgentFileSkillScriptTests
         Assert.Equal("/path/to/my-script.py", script.FullPath);
     }
 
+    [Fact]
+    public void ParametersSchema_ReturnsExpectedArraySchema()
+    {
+        // Arrange
+        static Task<object?> RunnerAsync(AgentFileSkill s, AgentFileSkillScript sc, JsonElement? a, IServiceProvider? sp, CancellationToken ct) => Task.FromResult<object?>(null);
+        var script = CreateScript("my-script", "/path/to/script.py", RunnerAsync);
+
+        // Act
+        var schema = script.ParametersSchema;
+
+        // Assert
+        Assert.NotNull(schema);
+        var raw = schema!.Value.GetRawText();
+        Assert.Contains("\"type\":\"array\"", raw);
+        Assert.Contains("\"items\":{\"type\":\"string\"}", raw);
+    }
+
+    [Fact]
+    public void Content_WithScripts_AppendsPerScriptEntries()
+    {
+        // Arrange
+        static Task<object?> RunnerAsync(AgentFileSkill s, AgentFileSkillScript sc, JsonElement? a, IServiceProvider? sp, CancellationToken ct) => Task.FromResult<object?>(null);
+        var script1 = CreateScript("build", "/scripts/build.sh", RunnerAsync);
+        var script2 = CreateScript("deploy", "/scripts/deploy.sh", RunnerAsync);
+        var fileSkill = new AgentFileSkill(
+            new AgentSkillFrontmatter("my-skill", "A skill"),
+            "Original content",
+            "/skills/my-skill",
+            scripts: [script1, script2]);
+
+        // Act
+        var content = fileSkill.Content;
+
+        // Assert — content starts with original and appends per-script entries
+        Assert.StartsWith("Original content", content);
+        Assert.Contains("<scripts>", content);
+        Assert.Contains("<script name=\"build\">", content);
+        Assert.Contains("<script name=\"deploy\">", content);
+        Assert.Contains("<parameters_schema>", content);
+        Assert.Contains("</scripts>", content);
+    }
+
+    [Fact]
+    public void Content_WithoutScripts_ReturnsOriginalContent()
+    {
+        // Arrange
+        var fileSkill = new AgentFileSkill(
+            new AgentSkillFrontmatter("my-skill", "A skill"),
+            "Original content only",
+            "/skills/my-skill");
+
+        // Act
+        var content = fileSkill.Content;
+
+        // Assert
+        Assert.Equal("Original content only", content);
+    }
+
+    [Fact]
+    public void Content_WithScripts_IsCached()
+    {
+        // Arrange
+        static Task<object?> RunnerAsync(AgentFileSkill s, AgentFileSkillScript sc, JsonElement? a, IServiceProvider? sp, CancellationToken ct) => Task.FromResult<object?>(null);
+        var script = CreateScript("test", "/scripts/test.sh", RunnerAsync);
+        var fileSkill = new AgentFileSkill(
+            new AgentSkillFrontmatter("my-skill", "A skill"),
+            "Content",
+            "/skills/my-skill",
+            scripts: [script]);
+
+        // Act
+        var content1 = fileSkill.Content;
+        var content2 = fileSkill.Content;
+
+        // Assert
+        Assert.Same(content1, content2);
+    }
+
+    [Fact]
+    public async Task RunAsync_ForwardsJsonArrayArgumentsToRunnerAsync()
+    {
+        // Arrange
+        JsonElement? capturedArgs = null;
+        Task<object?> runnerAsync(AgentFileSkill skill, AgentFileSkillScript scriptArg, JsonElement? args, IServiceProvider? sp, CancellationToken ct)
+        {
+            capturedArgs = args;
+            return Task.FromResult<object?>("done");
+        }
+        var script = CreateScript("array-test", "/scripts/test.sh", runnerAsync);
+        var fileSkill = new AgentFileSkill(
+            new AgentSkillFrontmatter("my-skill", "A skill"),
+            "Content",
+            "/skills/my-skill");
+        using var arrayArgsDoc = JsonDocument.Parse("""["arg1","arg2","arg3"]""");
+        var arrayArgs = arrayArgsDoc.RootElement;
+
+        // Act
+        await script.RunAsync(fileSkill, arrayArgs, null, CancellationToken.None);
+
+        // Assert — the raw JSON array is forwarded unchanged
+        Assert.NotNull(capturedArgs);
+        Assert.Equal(JsonValueKind.Array, capturedArgs!.Value.ValueKind);
+        Assert.Equal("""["arg1","arg2","arg3"]""", capturedArgs.Value.GetRawText());
+    }
+
+    [Fact]
+    public async Task RunAsync_ForwardsServiceProviderToRunnerAsync()
+    {
+        // Arrange
+        IServiceProvider? capturedProvider = null;
+        Task<object?> runnerAsync(AgentFileSkill skill, AgentFileSkillScript scriptArg, JsonElement? args, IServiceProvider? sp, CancellationToken ct)
+        {
+            capturedProvider = sp;
+            return Task.FromResult<object?>("done");
+        }
+        var script = CreateScript("sp-test", "/scripts/test.sh", runnerAsync);
+        var fileSkill = new AgentFileSkill(
+            new AgentSkillFrontmatter("my-skill", "A skill"),
+            "Content",
+            "/skills/my-skill");
+        var mockProvider = new TestServiceProvider();
+
+        // Act
+        await script.RunAsync(fileSkill, null, mockProvider, CancellationToken.None);
+
+        // Assert
+        Assert.Same(mockProvider, capturedProvider);
+    }
+
+    [Fact]
+    public async Task RunAsync_NoRunner_ThrowsInvalidOperationExceptionAsync()
+    {
+        // Arrange — create script without a runner
+        var script = CreateScript("no-runner", "/scripts/test.sh", runner: null);
+        var fileSkill = new AgentFileSkill(
+            new AgentSkillFrontmatter("my-skill", "A skill"),
+            "Content",
+            "/skills/my-skill");
+
+        // Act & Assert
+        await Assert.ThrowsAsync<InvalidOperationException>(
+            () => script.RunAsync(fileSkill, null, null, CancellationToken.None));
+    }
+
+    [Fact]
+    public void Content_WithScripts_ContainsDefaultParametersSchema()
+    {
+        // Arrange
+        static Task<object?> RunnerAsync(AgentFileSkill s, AgentFileSkillScript sc, JsonElement? a, IServiceProvider? sp, CancellationToken ct) => Task.FromResult<object?>(null);
+        var script = CreateScript("test", "/scripts/test.sh", RunnerAsync);
+        var fileSkill = new AgentFileSkill(
+            new AgentSkillFrontmatter("my-skill", "A skill"),
+            "Original content",
+            "/skills/my-skill",
+            scripts: [script]);
+
+        // Act
+        var content = fileSkill.Content;
+
+        // Assert — the appended block contains the actual default schema from AgentFileSkillScript
+        Assert.Contains("""{"type":"array","items":{"type":"string"}}""", content);
+    }
+
     /// <summary>
     /// Helper to create an <see cref="AgentFileSkillScript"/> via reflection since the constructor is internal.
     /// </summary>
-    private static AgentFileSkillScript CreateScript(string name, string fullPath, AgentFileSkillScriptRunner executor)
+    private static AgentFileSkillScript CreateScript(string name, string fullPath, AgentFileSkillScriptRunner? runner)
     {
         var ctor = typeof(AgentFileSkillScript).GetConstructor(
             System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance,
@@ -98,6 +261,14 @@ public sealed class AgentFileSkillScriptTests
             [typeof(string), typeof(string), typeof(AgentFileSkillScriptRunner)],
             null) ?? throw new InvalidOperationException("Could not find internal constructor.");
 
-        return (AgentFileSkillScript)ctor.Invoke([name, fullPath, executor]);
+        return (AgentFileSkillScript)ctor.Invoke([name, fullPath, runner]);
+    }
+
+    /// <summary>
+    /// Minimal <see cref="IServiceProvider"/> for testing service forwarding.
+    /// </summary>
+    private sealed class TestServiceProvider : IServiceProvider
+    {
+        public object? GetService(Type serviceType) => null;
     }
 }

dotnet/tests/Microsoft.Agents.AI.UnitTests/AgentSkills/AgentFileSkillsSourceScriptTests.cs

@@ -3,9 +3,9 @@
 using System;
 using System.IO;
 using System.Linq;
+using System.Text.Json;
 using System.Threading;
 using System.Threading.Tasks;
-using Microsoft.Extensions.AI;
 
 namespace Microsoft.Agents.AI.UnitTests.AgentSkills;
 
@@ -15,7 +15,7 @@ namespace Microsoft.Agents.AI.UnitTests.AgentSkills;
 public sealed class AgentFileSkillsSourceScriptTests : IDisposable
 {
     private static readonly string[] s_rubyExtension = new[] { ".rb" };
-    private static readonly AgentFileSkillScriptRunner s_noOpExecutor = (skill, script, args, ct) => Task.FromResult<object?>(null);
+    private static readonly AgentFileSkillScriptRunner s_noOpExecutor = (skill, script, args, sp, ct) => Task.FromResult<object?>(null);
 
     private readonly string _testRoot;
 
@@ -139,7 +139,7 @@ public sealed class AgentFileSkillsSourceScriptTests : IDisposable
         var executorCalled = false;
         var source = new AgentFileSkillsSource(
             this._testRoot,
-            (skill, script, args, ct) =>
+            (skill, script, args, sp, ct) =>
             {
                 executorCalled = true;
                 Assert.Equal("exec-skill", skill.Frontmatter.Name);
@@ -150,7 +150,7 @@ public sealed class AgentFileSkillsSourceScriptTests : IDisposable
 
         // Act
         var skills = await source.GetSkillsAsync(CancellationToken.None);
-        var scriptResult = await skills[0].Scripts![0].RunAsync(skills[0], new AIFunctionArguments(), CancellationToken.None);
+        var scriptResult = await skills[0].Scripts![0].RunAsync(skills[0], null, null, CancellationToken.None);
 
         // Assert
         Assert.True(executorCalled);
@@ -178,7 +178,7 @@ public sealed class AgentFileSkillsSourceScriptTests : IDisposable
         var script = skills[0].Scripts![0];
 
         // Assert — running the script throws because no runner was provided
-        await Assert.ThrowsAsync<InvalidOperationException>(() => script.RunAsync(skills[0], new AIFunctionArguments(), CancellationToken.None));
+        await Assert.ThrowsAsync<InvalidOperationException>(() => script.RunAsync(skills[0], null, null, CancellationToken.None));
     }
 
     [Fact]
@@ -204,10 +204,10 @@ public sealed class AgentFileSkillsSourceScriptTests : IDisposable
     {
         // Arrange
         CreateSkillWithScript(this._testRoot, "args-skill", "Args test", "Body.", "scripts/test.py", "print('ok')");
-        AIFunctionArguments? capturedArgs = null;
+        JsonElement? capturedArgs = null;
         var source = new AgentFileSkillsSource(
             this._testRoot,
-            (skill, script, args, ct) =>
+            (skill, script, args, sp, ct) =>
             {
                 capturedArgs = args;
                 return Task.FromResult<object?>("done");
@@ -215,17 +215,15 @@ public sealed class AgentFileSkillsSourceScriptTests : IDisposable
 
         // Act
         var skills = await source.GetSkillsAsync(CancellationToken.None);
-        var arguments = new AIFunctionArguments
-        {
-            ["value"] = 26.2,
-            ["factor"] = 1.60934
-        };
-        await skills[0].Scripts![0].RunAsync(skills[0], arguments, CancellationToken.None);
+        using var argumentsDoc = JsonDocument.Parse("""{"value":26.2,"factor":1.60934}""");
+        var arguments = argumentsDoc.RootElement;
+        await skills[0].Scripts![0].RunAsync(skills[0], arguments, null, CancellationToken.None);
 
         // Assert
         Assert.NotNull(capturedArgs);
-        Assert.Equal(26.2, capturedArgs["value"]);
-        Assert.Equal(1.60934, capturedArgs["factor"]);
+        Assert.Equal(JsonValueKind.Object, capturedArgs!.Value.ValueKind);
+        Assert.Equal(26.2, capturedArgs.Value.GetProperty("value").GetDouble());
+        Assert.Equal(1.60934, capturedArgs.Value.GetProperty("factor").GetDouble());
     }
 
     [Fact]

dotnet/tests/Microsoft.Agents.AI.UnitTests/AgentSkills/AgentInlineSkillScriptTests.cs

@@ -5,7 +5,6 @@ using System.Reflection;
 using System.Text.Json;
 using System.Threading;
 using System.Threading.Tasks;
-using Microsoft.Extensions.AI;
 
 namespace Microsoft.Agents.AI.UnitTests.AgentSkills;
 
@@ -22,7 +21,7 @@ public sealed class AgentInlineSkillScriptTests
         var skill = new AgentInlineSkill("test-skill", "Test.", "Instructions.");
 
         // Act
-        var result = await script.RunAsync(skill, new AIFunctionArguments(), CancellationToken.None);
+        var result = await script.RunAsync(skill, null, null, CancellationToken.None);
 
         // Assert
         Assert.Equal("hello", result?.ToString());
@@ -34,10 +33,11 @@ public sealed class AgentInlineSkillScriptTests
         // Arrange
         var script = new AgentInlineSkillScript("add", (int a, int b) => a + b);
         var skill = new AgentInlineSkill("calc-skill", "Calc.", "Instructions.");
-        var args = new AIFunctionArguments { ["a"] = 3, ["b"] = 7 };
+        using var argsDoc = JsonDocument.Parse("""{"a":3,"b":7}""");
+        var args = argsDoc.RootElement;
 
         // Act
-        var result = await script.RunAsync(skill, args, CancellationToken.None);
+        var result = await script.RunAsync(skill, args, null, CancellationToken.None);
 
         // Assert
         Assert.Equal(10, int.Parse(result?.ToString()!));
@@ -129,10 +129,11 @@ public sealed class AgentInlineSkillScriptTests
         }, serializerOptions: jso);
         var skill = new AgentInlineSkill("test-skill", "Test.", "Instructions.");
         var inputJson = JsonSerializer.SerializeToElement(new LookupRequest { Query = "test", MaxResults = 5 }, jso);
-        var args = new AIFunctionArguments { ["request"] = inputJson };
+        using var argsDoc = JsonDocument.Parse($$"""{ "request": {{inputJson.GetRawText()}} }""");
+        var args = argsDoc.RootElement;
 
         // Act
-        var result = await script.RunAsync(skill, args, CancellationToken.None);
+        var result = await script.RunAsync(skill, args, null, CancellationToken.None);
 
         // Assert — the custom input type was deserialized and the response was produced
         Assert.NotNull(result);
@@ -145,10 +146,11 @@ public sealed class AgentInlineSkillScriptTests
         // Arrange
         var script = new AgentInlineSkillScript("echo", (string message) => message);
         var skill = new AgentInlineSkill("test-skill", "Test.", "Instructions.");
-        var args = new AIFunctionArguments { ["message"] = "hello world" };
+        using var argsDoc = JsonDocument.Parse("""{"message":"hello world"}""");
+        var args = argsDoc.RootElement;
 
         // Act
-        var result = await script.RunAsync(skill, args, CancellationToken.None);
+        var result = await script.RunAsync(skill, args, null, CancellationToken.None);
 
         // Assert
         Assert.Equal("hello world", result?.ToString());
@@ -175,10 +177,11 @@ public sealed class AgentInlineSkillScriptTests
         var method = typeof(AgentInlineSkillScriptTests).GetMethod(nameof(StaticScriptHelper), BindingFlags.NonPublic | BindingFlags.Static)!;
         var script = new AgentInlineSkillScript("static-method-script", method, target: null);
         var skill = new AgentInlineSkill("test-skill", "Test.", "Instructions.");
-        var args = new AIFunctionArguments { ["input"] = "hello" };
+        using var argsDoc = JsonDocument.Parse("""{"input":"hello"}""");
+        var args = argsDoc.RootElement;
 
         // Act
-        var result = await script.RunAsync(skill, args, CancellationToken.None);
+        var result = await script.RunAsync(skill, args, null, CancellationToken.None);
 
         // Assert
         Assert.Equal("HELLO", result?.ToString());
@@ -191,10 +194,11 @@ public sealed class AgentInlineSkillScriptTests
         var method = typeof(AgentInlineSkillScriptTests).GetMethod(nameof(InstanceScriptHelper), BindingFlags.NonPublic | BindingFlags.Instance)!;
         var script = new AgentInlineSkillScript("instance-method-script", method, target: this);
         var skill = new AgentInlineSkill("test-skill", "Test.", "Instructions.");
-        var args = new AIFunctionArguments { ["input"] = "test" };
+        using var argsDoc2 = JsonDocument.Parse("""{"input":"test"}""");
+        var args2 = argsDoc2.RootElement;
 
         // Act
-        var result = await script.RunAsync(skill, args, CancellationToken.None);
+        var result = await script.RunAsync(skill, args2, null, CancellationToken.None);
 
         // Assert
         Assert.Equal("test-suffix", result?.ToString());
@@ -223,7 +227,63 @@ public sealed class AgentInlineSkillScriptTests
         Assert.Contains("input", schema!.Value.GetRawText());
     }
 
+    [Fact]
+    public async Task RunAsync_WithNonObjectArguments_ThrowsInvalidOperationExceptionAsync()
+    {
+        // Arrange — inline scripts require a JSON object for arguments
+        var script = new AgentInlineSkillScript("noop", () => "ok");
+        var skill = new AgentInlineSkill("test-skill", "Test.", "Instructions.");
+        using var arrayArgsDoc = JsonDocument.Parse("""["a","b"]""");
+        var arrayArgs = arrayArgsDoc.RootElement;
+
+        // Act & Assert — non-object JSON should fail fast rather than silently dropping arguments
+        await Assert.ThrowsAsync<InvalidOperationException>(
+            () => script.RunAsync(skill, arrayArgs, null, CancellationToken.None));
+    }
+
+    [Fact]
+    public async Task RunAsync_WithNullArguments_TreatsAsNoArgumentsAsync()
+    {
+        // Arrange — a parameterless delegate should succeed when given null arguments
+        var script = new AgentInlineSkillScript("noop", () => "ok");
+        var skill = new AgentInlineSkill("test-skill", "Test.", "Instructions.");
+
+        // Act
+        var result = await script.RunAsync(skill, null, null, CancellationToken.None);
+
+        // Assert
+        Assert.Equal("ok", result?.ToString());
+    }
+
+    [Fact]
+    public async Task RunAsync_ServiceProviderIsForwardedAsync()
+    {
+        // Arrange — delegate that resolves a service from the IServiceProvider
+        IServiceProvider? capturedProvider = null;
+        var script = new AgentInlineSkillScript("svc-test", (IServiceProvider sp) =>
+        {
+            capturedProvider = sp;
+            return "done";
+        });
+        var skill = new AgentInlineSkill("test-skill", "Test.", "Instructions.");
+        var mockProvider = new TestServiceProvider();
+
+        // Act
+        await script.RunAsync(skill, null, mockProvider, CancellationToken.None);
+
+        // Assert
+        Assert.Same(mockProvider, capturedProvider);
+    }
+
     private static string StaticScriptHelper(string input) => input.ToUpperInvariant();
 
     private string InstanceScriptHelper(string input) => input + "-suffix";
+
+    /// <summary>
+    /// Minimal <see cref="IServiceProvider"/> for testing service forwarding.
+    /// </summary>
+    private sealed class TestServiceProvider : IServiceProvider
+    {
+        public object? GetService(Type serviceType) => null;
+    }
 }

dotnet/tests/Microsoft.Agents.AI.UnitTests/AgentSkills/AgentInlineSkillTests.cs

@@ -433,10 +433,11 @@ public sealed class AgentInlineSkillTests
             TotalCount = request.MaxResults,
         });
         var inputJson = JsonSerializer.SerializeToElement(new LookupRequest { Query = "test", MaxResults = 3 }, jso);
-        var args = new AIFunctionArguments { ["request"] = inputJson };
+        using var argsDoc = JsonDocument.Parse($$"""{ "request": {{inputJson.GetRawText()}} }""");
+        var args = argsDoc.RootElement;
 
         // Act
-        var result = await skill.Scripts![0].RunAsync(skill, args, CancellationToken.None);
+        var result = await skill.Scripts![0].RunAsync(skill, args, null, CancellationToken.None);
 
         // Assert — the custom input was deserialized via skill-level JSO and response was produced
         Assert.NotNull(result);
@@ -456,10 +457,11 @@ public sealed class AgentInlineSkillTests
             TotalCount = request.MaxResults,
         }, serializerOptions: scriptJso);
         var inputJson = JsonSerializer.SerializeToElement(new LookupRequest { Query = "override", MaxResults = 7 }, scriptJso);
-        var args = new AIFunctionArguments { ["request"] = inputJson };
+        using var argsDoc = JsonDocument.Parse($$"""{ "request": {{inputJson.GetRawText()}} }""");
+        var args = argsDoc.RootElement;
 
         // Act
-        var result = await skill.Scripts![0].RunAsync(skill, args, CancellationToken.None);
+        var result = await skill.Scripts![0].RunAsync(skill, args, null, CancellationToken.None);
 
         // Assert — per-script JSO takes effect and custom types are properly marshaled
         Assert.NotNull(result);

dotnet/tests/Microsoft.Agents.AI.UnitTests/AgentSkills/AgentSkillsProviderTests.cs

@@ -4,6 +4,7 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Text.Json;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Extensions.AI;
@@ -15,7 +16,7 @@ namespace Microsoft.Agents.AI.UnitTests.AgentSkills;
 /// </summary>
 public sealed class AgentSkillsProviderTests : IDisposable
 {
-    private static readonly AgentFileSkillScriptRunner s_noOpExecutor = (skill, script, args, ct) => Task.FromResult<object?>(null);
+    private static readonly AgentFileSkillScriptRunner s_noOpExecutor = (skill, script, args, sp, ct) => Task.FromResult<object?>(null);
     private readonly string _testRoot;
     private readonly TestAIAgent _agent = new();
 
@@ -462,7 +463,7 @@ public sealed class AgentSkillsProviderTests : IDisposable
         // Act — call UseFileScriptRunner AFTER UseFileSkill (the bug scenario)
         var provider = new AgentSkillsProviderBuilder()
             .UseFileSkill(this._testRoot)
-            .UseFileScriptRunner((skill, script, args, ct) =>
+            .UseFileScriptRunner((skill, script, args, sp, ct) =>
             {
                 executorCalled = true;
                 return Task.FromResult<object?>("executed");
@@ -487,6 +488,62 @@ public sealed class AgentSkillsProviderTests : IDisposable
         Assert.True(executorCalled);
     }
 
+    [Fact]
+    public async Task RunSkillScript_ForwardsJsonArgumentsAndServiceProviderToRunnerAsync()
+    {
+        // Arrange — create a skill with a script file
+        string skillDir = Path.Combine(this._testRoot, "fwd-skill");
+        Directory.CreateDirectory(Path.Combine(skillDir, "scripts"));
+        File.WriteAllText(
+            Path.Combine(skillDir, "SKILL.md"),
+            "---\nname: fwd-skill\ndescription: Forwarding test\n---\nBody.");
+        File.WriteAllText(
+            Path.Combine(skillDir, "scripts", "run.py"),
+            "print('ok')");
+
+        JsonElement? capturedArgs = null;
+        IServiceProvider? capturedServiceProvider = null;
+
+        var provider = new AgentSkillsProviderBuilder()
+            .UseFileSkill(this._testRoot)
+            .UseFileScriptRunner((skill, script, args, sp, ct) =>
+            {
+                capturedArgs = args;
+                capturedServiceProvider = sp;
+                return Task.FromResult<object?>("executed");
+            })
+            .Build();
+
+        var mockServiceProvider = new TestServiceProvider();
+        var invokingContext = new AIContextProvider.InvokingContext(this._agent, session: null, new AIContext());
+        var result = await provider.InvokingAsync(invokingContext, CancellationToken.None);
+        var runScriptTool = result.Tools!.First(t => t.Name == "run_skill_script") as AIFunction;
+
+        // Act — invoke with JsonElement arguments and a service provider
+        using var argsJsonDoc = JsonDocument.Parse("""["arg1","arg2"]""");
+        var argsJson = argsJsonDoc.RootElement;
+        await runScriptTool!.InvokeAsync(new AIFunctionArguments(new Dictionary<string, object?>
+        {
+            ["skillName"] = "fwd-skill",
+            ["scriptName"] = "scripts/run.py",
+            ["arguments"] = argsJson,
+        })
+        {
+            Services = mockServiceProvider,
+        });
+
+        // Assert — JsonElement arguments and service provider are forwarded to the runner
+        Assert.NotNull(capturedArgs);
+        Assert.Equal(JsonValueKind.Array, capturedArgs!.Value.ValueKind);
+        Assert.Equal("""["arg1","arg2"]""", capturedArgs.Value.GetRawText());
+        Assert.Same(mockServiceProvider, capturedServiceProvider);
+    }
+
+    private sealed class TestServiceProvider : IServiceProvider
+    {
+        public object? GetService(Type serviceType) => null;
+    }
+
     private static void CreateSkillIn(string root, string name, string description, string body)
     {
         string skillDir = Path.Combine(root, name);

dotnet/tests/Microsoft.Agents.AI.UnitTests/AgentSkills/FileAgentSkillLoaderTests.cs

@@ -15,7 +15,7 @@ public sealed class FileAgentSkillLoaderTests : IDisposable
     private static readonly string[] s_customExtensions = [".custom"];
     private static readonly string[] s_validExtensions = [".md", ".json", ".custom"];
     private static readonly string[] s_mixedValidInvalidExtensions = [".md", "json"];
-    private static readonly AgentFileSkillScriptRunner s_noOpExecutor = (skill, script, args, ct) => Task.FromResult<object?>(null);
+    private static readonly AgentFileSkillScriptRunner s_noOpExecutor = (skill, script, args, sp, ct) => Task.FromResult<object?>(null);
 
     private readonly string _testRoot;
 

dotnet/tests/Microsoft.Agents.AI.Workflows.Declarative.IntegrationTests/Framework/IntegrationTest.cs

@@ -60,10 +60,20 @@ public abstract class IntegrationTest : IDisposable
 
     protected async ValueTask<DeclarativeWorkflowOptions> CreateOptionsAsync(bool externalConversation = false, params IEnumerable<AIFunction> functionTools)
     {
-        return await this.CreateOptionsAsync(externalConversation, mcpToolProvider: null, functionTools).ConfigureAwait(false);
+        return await this.CreateOptionsAsync(externalConversation, mcpToolProvider: null, httpRequestHandler: null, functionTools).ConfigureAwait(false);
     }
 
     protected async ValueTask<DeclarativeWorkflowOptions> CreateOptionsAsync(bool externalConversation, IMcpToolHandler? mcpToolProvider, params IEnumerable<AIFunction> functionTools)
+    {
+        return await this.CreateOptionsAsync(externalConversation, mcpToolProvider, httpRequestHandler: null, functionTools).ConfigureAwait(false);
+    }
+
+    protected async ValueTask<DeclarativeWorkflowOptions> CreateOptionsAsync(bool externalConversation, IHttpRequestHandler? httpRequestHandler, params IEnumerable<AIFunction> functionTools)
+    {
+        return await this.CreateOptionsAsync(externalConversation, mcpToolProvider: null, httpRequestHandler, functionTools).ConfigureAwait(false);
+    }
+
+    protected async ValueTask<DeclarativeWorkflowOptions> CreateOptionsAsync(bool externalConversation, IMcpToolHandler? mcpToolProvider, IHttpRequestHandler? httpRequestHandler, params IEnumerable<AIFunction> functionTools)
     {
         AzureAgentProvider agentProvider =
             new(this.TestEndpoint, TestAzureCliCredentials.CreateAzureCliCredential())
@@ -82,7 +92,8 @@ public abstract class IntegrationTest : IDisposable
             {
                 ConversationId = conversationId,
                 LoggerFactory = this.Output,
-                McpToolHandler = mcpToolProvider
+                McpToolHandler = mcpToolProvider,
+                HttpRequestHandler = httpRequestHandler,
             };
     }
 

dotnet/tests/Microsoft.Agents.AI.Workflows.Declarative.IntegrationTests/InvokeToolWorkflowTest.cs

@@ -45,6 +45,15 @@ public sealed class InvokeToolWorkflowTest(ITestOutputHelper output) : Integrati
 
     #endregion
 
+    #region InvokeHttpRequest Tests
+
+    [RetryTheory(3, 5000)]
+    [InlineData("HttpRequest.yaml", "visibility: public")]
+    public Task ValidateHttpRequestAsync(string workflowFileName, string? expectedResultContains) =>
+        this.RunHttpRequestTestAsync(workflowFileName, expectedResultContains);
+
+    #endregion
+
     #region InvokeFunctionTool Test Helpers
 
     /// <summary>
@@ -250,6 +259,40 @@ public sealed class InvokeToolWorkflowTest(ITestOutputHelper output) : Integrati
 
     #endregion
 
+    #region InvokeHttpRequest Test Helpers
+
+    /// <summary>
+    /// Runs an HttpRequestAction workflow test with the specified configuration.
+    /// </summary>
+    private async Task RunHttpRequestTestAsync(
+        string workflowFileName,
+        string? expectedResultContains = null)
+    {
+        // Arrange
+        string workflowPath = GetWorkflowPath(workflowFileName);
+        await using DefaultHttpRequestHandler httpRequestHandler = new();
+        DeclarativeWorkflowOptions workflowOptions = await this.CreateOptionsAsync(
+            externalConversation: false,
+            httpRequestHandler: httpRequestHandler);
+
+        Workflow workflow = DeclarativeWorkflowBuilder.Build<string>(workflowPath, workflowOptions);
+        WorkflowHarness harness = new(workflow, runId: Path.GetFileNameWithoutExtension(workflowPath));
+
+        // Act
+        WorkflowEvents workflowEvents = await harness.RunWorkflowAsync("start").ConfigureAwait(false);
+
+        // Assert - Verify executor and action events
+        AssertWorkflowEventsEmitted(workflowEvents);
+
+        // Assert - Verify expected result if specified
+        if (expectedResultContains is not null)
+        {
+            AssertResultContains(workflowEvents, expectedResultContains);
+        }
+    }
+
+    #endregion
+
     #region Shared Helpers
 
     private static void AssertWorkflowEventsEmitted(WorkflowEvents workflowEvents)

dotnet/tests/Microsoft.Agents.AI.Workflows.Declarative.IntegrationTests/Workflows/HttpRequest.yaml

@@ -0,0 +1,32 @@
+#
+# This workflow tests invoking HttpRequestAction end-to-end.
+# Uses the public GitHub API (unauthenticated) to fetch repo metadata.
+#
+kind: Workflow
+trigger:
+
+  kind: OnConversationStart
+  id: workflow_http_request_test
+  actions:
+
+    # Set the repo owner used to form the request URL.
+    - kind: SetVariable
+      id: set_repo_owner
+      variable: Local.RepoOwner
+      value: dotnet
+
+    # Invoke the GitHub repo API.
+    - kind: HttpRequestAction
+      id: fetch_repo_info
+      conversationId: =System.ConversationId
+      method: GET
+      url: =Concatenate("https://api.github.com/repos/", Local.RepoOwner, "/runtime")
+      headers:
+        Accept: application/vnd.github+json
+        User-Agent: agent-framework-integration-test
+      response: Local.RepoInfo
+
+    # Surface the Repo visibility field from the parsed JSON response.
+    - kind: SendMessage
+      id: show_visibility
+      message: "visibility: {Local.RepoInfo.visibility}"

dotnet/tests/Microsoft.Agents.AI.Workflows.Declarative.UnitTests/DeclarativeWorkflowTest.cs

@@ -181,6 +181,7 @@ public sealed class DeclarativeWorkflowTest(ITestOutputHelper output) : Workflow
     [InlineData("ResetVariable.yaml", 2, "clear_var")]
     [InlineData("MixedScopes.yaml", 2, "activity_input")]
     [InlineData("CaseInsensitive.yaml", 6, "end_when_match")]
+    [InlineData("HttpRequest.yaml", 1, "http_request")]
     public async Task ExecuteActionAsync(string workflowFile, int expectedCount, string expectedId)
     {
         await this.RunWorkflowAsync(workflowFile);
@@ -200,7 +201,6 @@ public sealed class DeclarativeWorkflowTest(ITestOutputHelper output) : Workflow
     [InlineData(typeof(EmitEvent.Builder))]
     [InlineData(typeof(GetActivityMembers.Builder))]
     [InlineData(typeof(GetConversationMembers.Builder))]
-    [InlineData(typeof(HttpRequestAction.Builder))]
     [InlineData(typeof(InvokeAIBuilderModelAction.Builder))]
     [InlineData(typeof(InvokeConnectorAction.Builder))]
     [InlineData(typeof(InvokeCustomModelAction.Builder))]
@@ -266,6 +266,7 @@ public sealed class DeclarativeWorkflowTest(ITestOutputHelper output) : Workflow
     [InlineData("SendActivity.yaml", "activity_input")]
     [InlineData("SetVariable.yaml", "set_var")]
     [InlineData("SetTextVariable.yaml", "set_text")]
+    [InlineData("HttpRequest.yaml", "http_request")]
     public async Task CancelRunAsync(string workflowPath, string expectedExecutedId)
     {
         // Arrange
@@ -374,7 +375,12 @@ public sealed class DeclarativeWorkflowTest(ITestOutputHelper output) : Workflow
     {
         using StreamReader yamlReader = File.OpenText(Path.Combine("Workflows", workflowPath));
         Mock<ResponseAgentProvider> mockAgentProvider = CreateMockProvider($"{workflowInput}");
-        DeclarativeWorkflowOptions workflowContext = new(mockAgentProvider.Object) { LoggerFactory = this.Output };
+        DeclarativeWorkflowOptions workflowContext =
+            new(mockAgentProvider.Object)
+            {
+                LoggerFactory = this.Output,
+                HttpRequestHandler = CreateMockHttpRequestHandler().Object,
+            };
         return DeclarativeWorkflowBuilder.Build<TInput>(yamlReader, workflowContext);
     }
 
@@ -385,4 +391,18 @@ public sealed class DeclarativeWorkflowTest(ITestOutputHelper output) : Workflow
         mockAgentProvider.Setup(provider => provider.CreateMessageAsync(It.IsAny<string>(), It.IsAny<ChatMessage>(), It.IsAny<CancellationToken>())).Returns(Task.FromResult(new ChatMessage(ChatRole.Assistant, input)));
         return mockAgentProvider;
     }
+
+    private static Mock<IHttpRequestHandler> CreateMockHttpRequestHandler()
+    {
+        Mock<IHttpRequestHandler> mockHandler = new(MockBehavior.Loose);
+        mockHandler
+            .Setup(handler => handler.SendAsync(It.IsAny<HttpRequestInfo>(), It.IsAny<CancellationToken>()))
+            .Returns(() => Task.FromResult(new HttpRequestResult
+            {
+                StatusCode = 200,
+                IsSuccessStatusCode = true,
+                Body = "{\"ok\":true}",
+            }));
+        return mockHandler;
+    }
 }

dotnet/tests/Microsoft.Agents.AI.Workflows.Declarative.UnitTests/DefaultHttpRequestHandlerTests.cs

@@ -0,0 +1,510 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using System.Collections.Generic;
+using System.Net;
+using System.Net.Http;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using FluentAssertions;
+
+namespace Microsoft.Agents.AI.Workflows.Declarative.UnitTests;
+
+/// <summary>
+/// Unit tests for <see cref="DefaultHttpRequestHandler"/>.
+/// </summary>
+public sealed class DefaultHttpRequestHandlerTests
+{
+    private static readonly string[] s_setCookieValues = ["a=1", "b=2"];
+
+    private const string TestUrl = "https://api.example.test/resource";
+
+    #region Constructor Tests
+
+    [Fact]
+    public async Task ConstructorWithNoParametersCreatesInstanceAsync()
+    {
+        // Act
+        await using DefaultHttpRequestHandler handler = new();
+
+        // Assert
+        handler.Should().NotBeNull();
+    }
+
+    [Fact]
+    public async Task ConstructorWithNullProviderCreatesInstanceAsync()
+    {
+        // Act
+        await using DefaultHttpRequestHandler handler = new(httpClientProvider: null);
+
+        // Assert
+        handler.Should().NotBeNull();
+    }
+
+    [Fact]
+    public void ConstructorWithNullHttpClientThrows()
+    {
+        // Act
+        Action act = () => _ = new DefaultHttpRequestHandler((HttpClient)null!);
+
+        // Assert
+        act.Should().Throw<ArgumentNullException>();
+    }
+
+    [Fact]
+    public async Task ConstructorWithHttpClientUsesSuppliedClientForAllRequestsAsync()
+    {
+        // Arrange
+        TestHttpMessageHandler messageHandler = new((req, _) =>
+            Task.FromResult(new HttpResponseMessage(HttpStatusCode.OK)
+            {
+                Content = new StringContent("ok", Encoding.UTF8, "text/plain"),
+            }));
+        using HttpClient suppliedClient = new(messageHandler);
+        await using DefaultHttpRequestHandler handler = new(suppliedClient);
+        HttpRequestInfo request = new() { Method = "GET", Url = TestUrl };
+
+        // Act
+        HttpRequestResult result = await handler.SendAsync(request);
+
+        // Assert - the supplied HttpClient's underlying handler saw the request
+        messageHandler.LastRequest.Should().NotBeNull();
+        messageHandler.LastRequest!.RequestUri!.ToString().Should().Be(TestUrl);
+        result.Body.Should().Be("ok");
+    }
+
+    [Fact]
+    public async Task DisposeAsyncDoesNotDisposeCallerSuppliedHttpClientAsync()
+    {
+        // Arrange
+        TestHttpMessageHandler messageHandler = new((req, _) =>
+            Task.FromResult(new HttpResponseMessage(HttpStatusCode.OK)));
+        using HttpClient suppliedClient = new(messageHandler);
+
+        // Act
+        DefaultHttpRequestHandler handler = new(suppliedClient);
+        await handler.DisposeAsync();
+
+        // Assert - supplied client remains usable (not disposed)
+        Func<Task> act = async () => await suppliedClient.GetAsync(new Uri(TestUrl));
+        await act.Should().NotThrowAsync<ObjectDisposedException>();
+    }
+
+    #endregion
+
+    #region Argument Validation Tests
+
+    [Fact]
+    public async Task SendAsyncWithNullRequestThrowsAsync()
+    {
+        // Arrange
+        await using DefaultHttpRequestHandler handler = new();
+
+        // Act
+        Func<Task> act = async () => await handler.SendAsync(null!);
+
+        // Assert
+        await act.Should().ThrowAsync<ArgumentNullException>();
+    }
+
+    [Fact]
+    public async Task SendAsyncWithEmptyUrlThrowsAsync()
+    {
+        // Arrange
+        await using DefaultHttpRequestHandler handler = new();
+        HttpRequestInfo request = new() { Method = "GET", Url = "" };
+
+        // Act
+        Func<Task> act = async () => await handler.SendAsync(request);
+
+        // Assert
+        await act.Should().ThrowAsync<ArgumentException>();
+    }
+
+    [Fact]
+    public async Task SendAsyncWithEmptyMethodThrowsAsync()
+    {
+        // Arrange
+        await using DefaultHttpRequestHandler handler = new();
+        HttpRequestInfo request = new() { Method = "", Url = TestUrl };
+
+        // Act
+        Func<Task> act = async () => await handler.SendAsync(request);
+
+        // Assert
+        await act.Should().ThrowAsync<ArgumentException>();
+    }
+
+    #endregion
+
+    #region Send Behavior Tests
+
+    [Fact]
+    public async Task SendAsyncUsesProvidedHttpClientAsync()
+    {
+        // Arrange
+        TestHttpMessageHandler messageHandler = new((req, _) =>
+            Task.FromResult(new HttpResponseMessage(HttpStatusCode.OK)
+            {
+                Content = new StringContent("hello", Encoding.UTF8, "text/plain"),
+            }));
+
+        await using DefaultHttpRequestHandler handler = new((_, _) => Task.FromResult<HttpClient?>(new HttpClient(messageHandler)));
+
+        HttpRequestInfo request = new() { Method = "GET", Url = TestUrl };
+
+        // Act
+        HttpRequestResult result = await handler.SendAsync(request);
+
+        // Assert
+        messageHandler.LastRequest.Should().NotBeNull();
+        messageHandler.LastRequest!.Method.Should().Be(HttpMethod.Get);
+        messageHandler.LastRequest.RequestUri!.ToString().Should().Be(TestUrl);
+        result.StatusCode.Should().Be(200);
+        result.IsSuccessStatusCode.Should().BeTrue();
+        result.Body.Should().Be("hello");
+    }
+
+    [Fact]
+    public async Task SendAsyncMapsAllKnownMethodsAsync()
+    {
+        // Arrange
+        TestHttpMessageHandler messageHandler = new((req, _) =>
+            Task.FromResult(new HttpResponseMessage(HttpStatusCode.OK)));
+
+        await using DefaultHttpRequestHandler handler = new((_, _) => Task.FromResult<HttpClient?>(new HttpClient(messageHandler)));
+
+        foreach (string method in new[] { "GET", "POST", "PUT", "PATCH", "DELETE", "CUSTOM" })
+        {
+            HttpRequestInfo request = new() { Method = method, Url = TestUrl };
+
+            // Act
+            await handler.SendAsync(request);
+
+            // Assert
+            messageHandler.LastRequest!.Method.Method.Should().Be(method);
+        }
+    }
+
+    [Fact]
+    public async Task SendAsyncNormalizesWhitespaceAroundCustomMethodAsync()
+    {
+        // Arrange
+        TestHttpMessageHandler messageHandler = new((req, _) =>
+            Task.FromResult(new HttpResponseMessage(HttpStatusCode.OK)));
+        await using DefaultHttpRequestHandler handler = new((_, _) => Task.FromResult<HttpClient?>(new HttpClient(messageHandler)));
+        HttpRequestInfo request = new() { Method = "  custom  ", Url = TestUrl };
+
+        // Act
+        await handler.SendAsync(request);
+
+        // Assert - fallback path should apply the same Trim/ToUpperInvariant normalization.
+        messageHandler.LastRequest!.Method.Method.Should().Be("CUSTOM");
+    }
+
+    [Fact]
+    public async Task SendAsyncAppliesBodyAndContentTypeAsync()
+    {
+        // Arrange
+        TestHttpMessageHandler messageHandler = new((req, _) =>
+            Task.FromResult(new HttpResponseMessage(HttpStatusCode.OK)));
+
+        await using DefaultHttpRequestHandler handler = new((_, _) => Task.FromResult<HttpClient?>(new HttpClient(messageHandler)));
+
+        HttpRequestInfo request = new()
+        {
+            Method = "POST",
+            Url = TestUrl,
+            Body = "{\"hello\":\"world\"}",
+            BodyContentType = "application/json",
+        };
+
+        // Act
+        await handler.SendAsync(request);
+
+        // Assert
+        messageHandler.LastRequestBody.Should().Be("{\"hello\":\"world\"}");
+        messageHandler.LastRequestContentType.Should().Be("application/json");
+    }
+
+    [Fact]
+    public async Task SendAsyncAppliesRequestHeadersAsync()
+    {
+        // Arrange
+        TestHttpMessageHandler messageHandler = new((req, _) =>
+            Task.FromResult(new HttpResponseMessage(HttpStatusCode.OK)));
+
+        await using DefaultHttpRequestHandler handler = new((_, _) => Task.FromResult<HttpClient?>(new HttpClient(messageHandler)));
+
+        HttpRequestInfo request = new()
+        {
+            Method = "GET",
+            Url = TestUrl,
+            Headers = new Dictionary<string, string>
+            {
+                ["Authorization"] = "Bearer secret",
+                ["Accept"] = "application/json",
+            },
+        };
+
+        // Act
+        await handler.SendAsync(request);
+
+        // Assert
+        messageHandler.LastRequest!.Headers.Authorization!.ToString().Should().Be("Bearer secret");
+        messageHandler.LastRequest.Headers.Accept.Should().Contain(mediaType => mediaType.MediaType == "application/json");
+    }
+
+    [Fact]
+    public async Task SendAsyncRoutesContentHeadersToBodyAsync()
+    {
+        // Arrange
+        TestHttpMessageHandler messageHandler = new((req, _) =>
+            Task.FromResult(new HttpResponseMessage(HttpStatusCode.OK)));
+
+        await using DefaultHttpRequestHandler handler = new((_, _) => Task.FromResult<HttpClient?>(new HttpClient(messageHandler)));
+
+        HttpRequestInfo request = new()
+        {
+            Method = "POST",
+            Url = TestUrl,
+            Body = "raw",
+            BodyContentType = "text/plain",
+            Headers = new Dictionary<string, string>
+            {
+                ["Content-Language"] = "en-US",
+            },
+        };
+
+        // Act
+        await handler.SendAsync(request);
+
+        // Assert
+        messageHandler.LastRequest!.Content!.Headers.ContentLanguage.Should().Contain("en-US");
+    }
+
+    [Fact]
+    public async Task SendAsyncCapturesResponseHeadersAsync()
+    {
+        // Arrange
+        TestHttpMessageHandler messageHandler = new((req, _) =>
+        {
+#pragma warning disable CA2025
+            HttpResponseMessage response = new(HttpStatusCode.OK)
+            {
+                Content = new StringContent("ok", Encoding.UTF8, "text/plain"),
+            };
+            response.Headers.Add("X-Request-Id", "request-1");
+            response.Headers.Add("Set-Cookie", s_setCookieValues);
+            return Task.FromResult(response);
+#pragma warning restore CA2025
+        });
+
+        await using DefaultHttpRequestHandler handler = new((_, _) => Task.FromResult<HttpClient?>(new HttpClient(messageHandler)));
+
+        HttpRequestInfo request = new() { Method = "GET", Url = TestUrl };
+
+        // Act
+        HttpRequestResult result = await handler.SendAsync(request);
+
+        // Assert
+        result.Headers.Should().NotBeNull();
+        result.Headers!.Should().ContainKey("X-Request-Id");
+        result.Headers!["Set-Cookie"].Should().BeEquivalentTo(s_setCookieValues);
+        // Content headers also flattened in.
+        result.Headers!.Should().ContainKey("Content-Type");
+    }
+
+    [Fact]
+    public async Task SendAsyncReturnsFailureStatusWithoutThrowingAsync()
+    {
+        // Arrange
+        TestHttpMessageHandler messageHandler = new((req, _) =>
+            Task.FromResult(new HttpResponseMessage(HttpStatusCode.BadRequest)
+            {
+                Content = new StringContent("bad request", Encoding.UTF8, "text/plain"),
+            }));
+
+        await using DefaultHttpRequestHandler handler = new((_, _) => Task.FromResult<HttpClient?>(new HttpClient(messageHandler)));
+
+        HttpRequestInfo request = new() { Method = "GET", Url = TestUrl };
+
+        // Act
+        HttpRequestResult result = await handler.SendAsync(request);
+
+        // Assert
+        result.IsSuccessStatusCode.Should().BeFalse();
+        result.StatusCode.Should().Be(400);
+        result.Body.Should().Be("bad request");
+    }
+
+    [Fact]
+    public async Task SendAsyncTimeoutCancelsRequestAsync()
+    {
+        // Arrange
+        TestHttpMessageHandler messageHandler = new(async (req, ct) =>
+        {
+            await Task.Delay(TimeSpan.FromSeconds(5), ct).ConfigureAwait(false);
+            return new HttpResponseMessage(HttpStatusCode.OK);
+        });
+
+        await using DefaultHttpRequestHandler handler = new((_, _) => Task.FromResult<HttpClient?>(new HttpClient(messageHandler)));
+
+        HttpRequestInfo request = new()
+        {
+            Method = "GET",
+            Url = TestUrl,
+            Timeout = TimeSpan.FromMilliseconds(50),
+        };
+
+        // Act
+        Func<Task> act = async () => await handler.SendAsync(request);
+
+        // Assert
+        await act.Should().ThrowAsync<OperationCanceledException>();
+    }
+
+    [Fact]
+    public async Task SendAsyncFallsBackToOwnedClientWhenProviderReturnsNullAsync()
+    {
+        // Arrange
+        int providerCallCount = 0;
+        await using DefaultHttpRequestHandler handler = new((_, _) =>
+        {
+            providerCallCount++;
+            return Task.FromResult<HttpClient?>(null);
+        });
+
+        HttpRequestInfo request = new() { Method = "GET", Url = "http://127.0.0.1:1/" };
+
+        // Act - owned client will attempt real network and fail, but provider path should have been consulted first.
+        Func<Task> act = async () => await handler.SendAsync(request);
+
+        // Assert
+        await act.Should().ThrowAsync<Exception>();
+        providerCallCount.Should().Be(1);
+    }
+
+    #endregion
+
+    #region DisposeAsync
+
+    [Fact]
+    public async Task DisposeAsyncCompletesAsync()
+    {
+        // Arrange
+        DefaultHttpRequestHandler handler = new();
+
+        // Act
+        Func<Task> act = async () => await handler.DisposeAsync();
+
+        // Assert
+        await act.Should().NotThrowAsync();
+    }
+
+    [Fact]
+    public async Task DisposeAsyncCalledMultipleTimesSucceedsAsync()
+    {
+        // Arrange
+        DefaultHttpRequestHandler handler = new();
+
+        // Act
+        await handler.DisposeAsync();
+        Func<Task> second = async () => await handler.DisposeAsync();
+
+        // Assert
+        await second.Should().NotThrowAsync();
+    }
+
+    #endregion
+
+    #region Query Parameters and Connection Tests
+
+    [Fact]
+    public async Task QueryParametersAreAppendedToUrlAsync()
+    {
+        // Arrange
+        TestHttpMessageHandler fake = new(static (req, _) =>
+            Task.FromResult(new HttpResponseMessage(HttpStatusCode.OK) { Content = new StringContent(string.Empty) }));
+        await using DefaultHttpRequestHandler handler = new((_, _) => Task.FromResult<HttpClient?>(new HttpClient(fake)));
+
+        HttpRequestInfo info = new()
+        {
+            Method = "GET",
+            Url = TestUrl,
+            QueryParameters = new Dictionary<string, string>
+            {
+                ["filter"] = "active items",
+                ["ids"] = "1,2,3",
+            },
+        };
+
+        // Act
+        await handler.SendAsync(info);
+
+        // Assert
+        fake.LastRequest.Should().NotBeNull();
+        string? query = fake.LastRequest!.RequestUri!.Query;
+        query.Should().Contain("filter=active%20items");
+        query.Should().Contain("ids=1%2C2%2C3");
+    }
+
+    [Fact]
+    public async Task QueryParametersPreserveExistingQueryStringAsync()
+    {
+        // Arrange
+        TestHttpMessageHandler fake = new(static (req, _) =>
+            Task.FromResult(new HttpResponseMessage(HttpStatusCode.OK) { Content = new StringContent(string.Empty) }));
+        await using DefaultHttpRequestHandler handler = new((_, _) => Task.FromResult<HttpClient?>(new HttpClient(fake)));
+
+        HttpRequestInfo info = new()
+        {
+            Method = "GET",
+            Url = TestUrl + "?existing=yes",
+            QueryParameters = new Dictionary<string, string>
+            {
+                ["added"] = "true",
+            },
+        };
+
+        // Act
+        await handler.SendAsync(info);
+
+        // Assert
+        fake.LastRequest!.RequestUri!.Query.Should().Be("?existing=yes&added=true");
+    }
+
+    #endregion
+
+    private sealed class TestHttpMessageHandler : HttpMessageHandler
+    {
+        private readonly Func<HttpRequestMessage, CancellationToken, Task<HttpResponseMessage>> _responseFactory;
+
+        public TestHttpMessageHandler(Func<HttpRequestMessage, CancellationToken, Task<HttpResponseMessage>> responseFactory)
+        {
+            this._responseFactory = responseFactory;
+        }
+
+        public HttpRequestMessage? LastRequest { get; private set; }
+
+        public string? LastRequestBody { get; private set; }
+
+        public string? LastRequestContentType { get; private set; }
+
+        protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
+        {
+            this.LastRequest = request;
+            if (request.Content is not null)
+            {
+#if NET
+                this.LastRequestBody = await request.Content.ReadAsStringAsync(cancellationToken).ConfigureAwait(false);
+#else
+                this.LastRequestBody = await request.Content.ReadAsStringAsync().ConfigureAwait(false);
+#endif
+                this.LastRequestContentType = request.Content.Headers.ContentType?.MediaType;
+            }
+            return await this._responseFactory(request, cancellationToken).ConfigureAwait(false);
+        }
+    }
+}

dotnet/tests/Microsoft.Agents.AI.Workflows.Declarative.UnitTests/Extensions/ChatMessageExtensionsTests.cs

@@ -769,4 +769,165 @@ public sealed class ChatMessageExtensionsTests
                 break;
         }
     }
+
+    [Fact]
+    public void MergeForLastMessageReturnsInputWhenInputMessageIsNull()
+    {
+        // Arrange
+        ChatMessage input = new(ChatRole.User, "hello") { MessageId = "local" };
+
+        // Act
+        ChatMessage result = input.MergeForLastMessage(null);
+
+        // Assert
+        Assert.Same(input, result);
+    }
+
+    [Fact]
+    public void MergeForLastMessageReturnsSameInstanceAsRoundTripped()
+    {
+        // Arrange: returning the round-tripped instance keeps the merge forward-compatible
+        // with future ChatMessage properties (e.g., new metadata fields) without explicit copies.
+        ChatMessage input = new(ChatRole.User, "original");
+        ChatMessage roundTripped = new(ChatRole.User, "stripped") { MessageId = "server" };
+
+        // Act
+        ChatMessage result = input.MergeForLastMessage(roundTripped);
+
+        // Assert
+        Assert.Same(roundTripped, result);
+    }
+
+    [Fact]
+    public void MergeForLastMessagePrefersOriginalTextOverRoundTrippedText()
+    {
+        // Arrange
+        ChatMessage input = new(ChatRole.User, "original text");
+        ChatMessage roundTripped = new(ChatRole.User, "stripped") { MessageId = "server-id" };
+
+        // Act
+        ChatMessage result = input.MergeForLastMessage(roundTripped);
+
+        // Assert
+        Assert.Equal("server-id", result.MessageId);
+        Assert.Equal("original text", result.Text);
+        TextContent text = Assert.IsType<TextContent>(Assert.Single(result.Contents));
+        Assert.Equal("original text", text.Text);
+    }
+
+    [Fact]
+    public void MergeForLastMessageReplacesTextInPlaceAndKeepsServerMedia()
+    {
+        // Arrange
+        HostedFileContent serverRef = new("file-abc");
+        ChatMessage input = new(ChatRole.User, [new TextContent("look at this:"), new DataContent("data:image/jpeg;base64,QUJD", "image/jpeg")]);
+        ChatMessage roundTripped = new(ChatRole.User, [new TextContent("stripped"), serverRef]) { MessageId = "server-id" };
+
+        // Act
+        ChatMessage result = input.MergeForLastMessage(roundTripped);
+
+        // Assert: server's text slot is replaced with original text; server's media reference is preserved.
+        Assert.Equal("server-id", result.MessageId);
+        Assert.Collection(result.Contents,
+            c => Assert.Equal("look at this:", Assert.IsType<TextContent>(c).Text),
+            c => Assert.Same(serverRef, c));
+    }
+
+    [Fact]
+    public void MergeForLastMessageAppendsOriginalTextWhenRoundTripHasNoTextSlot()
+    {
+        // Arrange: round-tripped message has only media (no text slot to replace).
+        HostedFileContent serverRef = new("file-1");
+        ChatMessage input = new(ChatRole.User, [new TextContent("middle"), new DataContent("data:image/jpeg;base64,QUE=", "image/jpeg")]);
+        ChatMessage roundTripped = new(ChatRole.User, [serverRef]) { MessageId = "id" };
+
+        // Act
+        ChatMessage result = input.MergeForLastMessage(roundTripped);
+
+        // Assert: media kept; original text appended at end.
+        Assert.Collection(result.Contents,
+            c => Assert.Same(serverRef, c),
+            c => Assert.Equal("middle", Assert.IsType<TextContent>(c).Text));
+    }
+
+    [Fact]
+    public void MergeForLastMessageReplacesMultipleTextSlotsInOrder()
+    {
+        // Arrange: input has two text items; round-tripped has two text slots interleaved with media.
+        HostedFileContent firstRef = new("file-1");
+        HostedFileContent secondRef = new("file-2");
+        ChatMessage input = new(ChatRole.User, [new TextContent("first"), new TextContent("second")]);
+        ChatMessage roundTripped = new(ChatRole.User, [firstRef, new TextContent("a"), secondRef, new TextContent("b")]) { MessageId = "id" };
+
+        // Act
+        ChatMessage result = input.MergeForLastMessage(roundTripped);
+
+        // Assert
+        Assert.Collection(result.Contents,
+            c => Assert.Same(firstRef, c),
+            c => Assert.Equal("first", Assert.IsType<TextContent>(c).Text),
+            c => Assert.Same(secondRef, c),
+            c => Assert.Equal("second", Assert.IsType<TextContent>(c).Text));
+    }
+
+    [Fact]
+    public void MergeForLastMessageFallsBackToInputTextWhenInputHasNoTextContent()
+    {
+        // Arrange: ChatMessage(role, "string") populates Text but no explicit TextContent
+        // when Contents is initially empty in some construction paths. Verify we still
+        // recover the original Text via input.Text.
+        ChatMessage input = new(ChatRole.User, "fallback text");
+        ChatMessage roundTripped = new(ChatRole.User, [new TextContent("stripped")]) { MessageId = "id" };
+
+        // Act
+        ChatMessage result = input.MergeForLastMessage(roundTripped);
+
+        // Assert
+        Assert.Equal("fallback text", Assert.IsType<TextContent>(Assert.Single(result.Contents)).Text);
+    }
+
+    [Fact]
+    public void MergeForLastMessagePreservesServerAuthoredProperties()
+    {
+        // Arrange: server (round-trip) is authoritative for metadata. Returning the
+        // round-tripped instance means any future ChatMessage property is automatically
+        // preserved without code changes here.
+        ChatMessage input = new(ChatRole.User, "hi")
+        {
+            AuthorName = "client-side",
+            AdditionalProperties = new AdditionalPropertiesDictionary { ["client"] = "value" },
+        };
+        ChatMessage roundTripped = new(ChatRole.User, [new TextContent("stripped")])
+        {
+            MessageId = "server",
+            AuthorName = "server-side",
+            AdditionalProperties = new AdditionalPropertiesDictionary { ["server"] = "value" },
+        };
+
+        // Act
+        ChatMessage result = input.MergeForLastMessage(roundTripped);
+
+        // Assert
+        Assert.Equal("server", result.MessageId);
+        Assert.Equal("server-side", result.AuthorName);
+        Assert.NotNull(result.AdditionalProperties);
+        Assert.True(result.AdditionalProperties.ContainsKey("server"));
+        Assert.False(result.AdditionalProperties.ContainsKey("client"));
+    }
+
+    [Fact]
+    public void MergeForLastMessageHandlesEmptyInputContents()
+    {
+        // Arrange
+        ChatMessage input = new(ChatRole.User, new List<AIContent>());
+        HostedFileContent serverRef = new("file-only");
+        ChatMessage roundTripped = new(ChatRole.User, [serverRef]) { MessageId = "id" };
+
+        // Act
+        ChatMessage result = input.MergeForLastMessage(roundTripped);
+
+        // Assert: nothing to splice; round-tripped returned unchanged.
+        Assert.Same(roundTripped, result);
+        Assert.Equal("file-only", Assert.IsType<HostedFileContent>(Assert.Single(result.Contents)).FileId);
+    }
 }

dotnet/tests/Microsoft.Agents.AI.Workflows.Declarative.UnitTests/ObjectModel/HttpRequestExecutorTest.cs

@@ -0,0 +1,759 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Agents.AI.Workflows.Declarative.ObjectModel;
+using Microsoft.Agents.AI.Workflows.Declarative.PowerFx;
+using Microsoft.Agents.ObjectModel;
+using Microsoft.Extensions.AI;
+using Microsoft.PowerFx.Types;
+using Moq;
+
+namespace Microsoft.Agents.AI.Workflows.Declarative.UnitTests.ObjectModel;
+
+/// <summary>
+/// Tests for <see cref="HttpRequestExecutor"/>.
+/// </summary>
+public sealed class HttpRequestExecutorTest(ITestOutputHelper output) : WorkflowActionExecutorTest(output)
+{
+    private const string TestUrl = "https://api.example.com/data";
+
+    private readonly Mock<ResponseAgentProvider> _agentProvider = new(MockBehavior.Loose);
+
+    [Fact]
+    public void InvalidModel()
+    {
+        // Arrange
+        Mock<IHttpRequestHandler> mockHandler = new();
+
+        // Act & Assert
+        Assert.Throws<DeclarativeModelException>(() => new HttpRequestExecutor(
+            new HttpRequestAction(),
+            mockHandler.Object,
+            this._agentProvider.Object,
+            this.State));
+    }
+
+    [Fact]
+    public void HttpRequestIsDiscreteAction()
+    {
+        // Arrange
+        Mock<IHttpRequestHandler> mockHandler = new();
+        HttpRequestAction model = this.CreateModel(
+            displayName: nameof(HttpRequestIsDiscreteAction),
+            url: TestUrl,
+            method: HttpMethodType.Get);
+        HttpRequestExecutor action = new(model, mockHandler.Object, this._agentProvider.Object, this.State);
+
+        // Act & Assert — IsDiscreteAction should be true for HttpRequest (single-step action).
+        VerifyIsDiscrete(action, isDiscrete: true);
+    }
+
+    [Fact]
+    public async Task HttpGetReturnsJsonObjectAsync()
+    {
+        // Arrange
+        this.State.InitializeSystem();
+        const string ResponseVar = "Result";
+        HttpRequestAction model = this.CreateModel(
+            displayName: nameof(HttpGetReturnsJsonObjectAsync),
+            url: TestUrl,
+            method: HttpMethodType.Get,
+            responseVariable: ResponseVar);
+
+        MockHttpRequestHandler handler = new(HttpRequestResult("{\"key\":\"value\",\"number\":42}"));
+        HttpRequestExecutor action = new(model, handler.Object, this._agentProvider.Object, this.State);
+
+        // Act
+        await this.ExecuteAsync(action);
+
+        // Assert
+        VerifyModel(model, action);
+        Assert.IsType<RecordValue>(this.State.Get(ResponseVar), exactMatch: false);
+        handler.VerifySent(info => info.Method == "GET" && info.Url == TestUrl);
+    }
+
+    [Fact]
+    public async Task HttpGetReturnsPlainStringAsync()
+    {
+        // Arrange
+        this.State.InitializeSystem();
+        const string ResponseVar = "Result";
+        HttpRequestAction model = this.CreateModel(
+            displayName: nameof(HttpGetReturnsPlainStringAsync),
+            url: TestUrl,
+            method: HttpMethodType.Get,
+            responseVariable: ResponseVar);
+
+        MockHttpRequestHandler handler = new(HttpRequestResult("not-json content"));
+        HttpRequestExecutor action = new(model, handler.Object, this._agentProvider.Object, this.State);
+
+        // Act
+        await this.ExecuteAsync(action);
+
+        // Assert
+        VerifyModel(model, action);
+        this.VerifyState(ResponseVar, FormulaValue.New("not-json content"));
+    }
+
+    [Fact]
+    public async Task HttpGetWithEmptyBodyYieldsBlankAsync()
+    {
+        // Arrange
+        this.State.InitializeSystem();
+        const string ResponseVar = "Result";
+        HttpRequestAction model = this.CreateModel(
+            displayName: nameof(HttpGetWithEmptyBodyYieldsBlankAsync),
+            url: TestUrl,
+            method: HttpMethodType.Get,
+            responseVariable: ResponseVar);
+
+        MockHttpRequestHandler handler = new(HttpRequestResult(null));
+        HttpRequestExecutor action = new(model, handler.Object, this._agentProvider.Object, this.State);
+
+        // Act
+        await this.ExecuteAsync(action);
+
+        // Assert
+        VerifyModel(model, action);
+        this.VerifyUndefined(ResponseVar);
+    }
+
+    [Fact]
+    public async Task HttpGetForwardsHeadersAsync()
+    {
+        // Arrange
+        this.State.InitializeSystem();
+        HttpRequestAction model = this.CreateModel(
+            displayName: nameof(HttpGetForwardsHeadersAsync),
+            url: TestUrl,
+            method: HttpMethodType.Get,
+            headers: new Dictionary<string, string>
+            {
+                ["Authorization"] = "Bearer token",
+                ["Accept"] = "application/json",
+            });
+
+        MockHttpRequestHandler handler = new(HttpRequestResult("{}"));
+        HttpRequestExecutor action = new(model, handler.Object, this._agentProvider.Object, this.State);
+
+        // Act
+        await this.ExecuteAsync(action);
+
+        // Assert
+        VerifyModel(model, action);
+        handler.VerifySent(info =>
+            info.Headers?["Authorization"] == "Bearer token" &&
+            info.Headers?["Accept"] == "application/json");
+    }
+
+    [Fact]
+    public async Task HttpPostWithJsonBodyAsync()
+    {
+        // Arrange
+        this.State.InitializeSystem();
+        HttpRequestAction model = this.CreateModel(
+            displayName: nameof(HttpPostWithJsonBodyAsync),
+            url: TestUrl,
+            method: HttpMethodType.Post,
+            jsonBody: new StringDataValue("hello"));
+
+        MockHttpRequestHandler handler = new(HttpRequestResult("{}"));
+        HttpRequestExecutor action = new(model, handler.Object, this._agentProvider.Object, this.State);
+
+        // Act
+        await this.ExecuteAsync(action);
+
+        // Assert
+        VerifyModel(model, action);
+        handler.VerifySent(info =>
+            info.Method == "POST" &&
+            info.BodyContentType == "application/json" &&
+            info.Body == "\"hello\"");
+    }
+
+    [Fact]
+    public async Task HttpPostWithRawBodyAsync()
+    {
+        // Arrange
+        this.State.InitializeSystem();
+        HttpRequestAction model = this.CreateModel(
+            displayName: nameof(HttpPostWithRawBodyAsync),
+            url: TestUrl,
+            method: HttpMethodType.Post,
+            rawBody: "raw body content",
+            rawContentType: "text/plain");
+
+        MockHttpRequestHandler handler = new(HttpRequestResult(""));
+        HttpRequestExecutor action = new(model, handler.Object, this._agentProvider.Object, this.State);
+
+        // Act
+        await this.ExecuteAsync(action);
+
+        // Assert
+        VerifyModel(model, action);
+        handler.VerifySent(info =>
+            info.BodyContentType == "text/plain" &&
+            info.Body == "raw body content");
+    }
+
+    [Fact]
+    public async Task HttpRequestRaisesOnErrorByDefaultAsync()
+    {
+        // Arrange
+        this.State.InitializeSystem();
+        HttpRequestAction model = this.CreateModel(
+            displayName: nameof(HttpRequestRaisesOnErrorByDefaultAsync),
+            url: TestUrl,
+            method: HttpMethodType.Get);
+
+        MockHttpRequestHandler handler = new(HttpRequestResult("server error", statusCode: 500, isSuccess: false));
+        HttpRequestExecutor action = new(model, handler.Object, this._agentProvider.Object, this.State);
+
+        // Act & Assert
+        await Assert.ThrowsAsync<DeclarativeActionException>(() => this.ExecuteAsync(action));
+    }
+
+    [Fact]
+    public async Task HttpRequestFailureExceptionTruncatesLongBodyAsync()
+    {
+        // Arrange
+        this.State.InitializeSystem();
+        HttpRequestAction model = this.CreateModel(
+            displayName: nameof(HttpRequestFailureExceptionTruncatesLongBodyAsync),
+            url: TestUrl,
+            method: HttpMethodType.Get);
+
+        string longBody = new('x', 10_000);
+        MockHttpRequestHandler handler = new(HttpRequestResult(longBody, statusCode: 500, isSuccess: false));
+        HttpRequestExecutor action = new(model, handler.Object, this._agentProvider.Object, this.State);
+
+        // Act
+        DeclarativeActionException exception =
+            await Assert.ThrowsAsync<DeclarativeActionException>(() => this.ExecuteAsync(action));
+
+        // Assert - message contains status and truncation marker, bounded in length, never the full body.
+        Assert.Contains("500", exception.Message);
+        Assert.Contains("[truncated]", exception.Message);
+        Assert.DoesNotContain(longBody, exception.Message);
+        Assert.True(exception.Message.Length < 512, $"Exception message too long: {exception.Message.Length} chars.");
+    }
+
+    [Fact]
+    public async Task HttpRequestFailureExceptionOmitsEmptyBodyAsync()
+    {
+        // Arrange
+        this.State.InitializeSystem();
+        HttpRequestAction model = this.CreateModel(
+            displayName: nameof(HttpRequestFailureExceptionOmitsEmptyBodyAsync),
+            url: TestUrl,
+            method: HttpMethodType.Get);
+
+        MockHttpRequestHandler handler = new(HttpRequestResult(body: null, statusCode: 404, isSuccess: false));
+        HttpRequestExecutor action = new(model, handler.Object, this._agentProvider.Object, this.State);
+
+        // Act
+        DeclarativeActionException exception =
+            await Assert.ThrowsAsync<DeclarativeActionException>(() => this.ExecuteAsync(action));
+
+        // Assert - status present, no stray "Body: ''" noise.
+        Assert.Contains("404", exception.Message);
+        Assert.DoesNotContain("Body:", exception.Message);
+    }
+
+    [Fact]
+    public async Task HttpRequestFailureExceptionSanitizesControlCharsAsync()
+    {
+        // Arrange
+        this.State.InitializeSystem();
+        HttpRequestAction model = this.CreateModel(
+            displayName: nameof(HttpRequestFailureExceptionSanitizesControlCharsAsync),
+            url: TestUrl,
+            method: HttpMethodType.Get);
+
+        MockHttpRequestHandler handler = new(HttpRequestResult("line1\r\nline2\tend", statusCode: 400, isSuccess: false));
+        HttpRequestExecutor action = new(model, handler.Object, this._agentProvider.Object, this.State);
+
+        // Act
+        DeclarativeActionException exception =
+            await Assert.ThrowsAsync<DeclarativeActionException>(() => this.ExecuteAsync(action));
+
+        // Assert - CR/LF/TAB collapsed to spaces so the message stays on one line.
+        Assert.DoesNotContain("\r", exception.Message);
+        Assert.DoesNotContain("\n", exception.Message);
+        Assert.DoesNotContain("\t", exception.Message);
+        Assert.Contains("line1", exception.Message);
+        Assert.Contains("line2", exception.Message);
+    }
+
+    [Fact]
+    public async Task HttpRequestPassesTimeoutToHandlerAsync()
+    {
+        // Arrange
+        this.State.InitializeSystem();
+        HttpRequestAction model = this.CreateModel(
+            displayName: nameof(HttpRequestPassesTimeoutToHandlerAsync),
+            url: TestUrl,
+            method: HttpMethodType.Get,
+            timeoutMilliseconds: 1500);
+
+        MockHttpRequestHandler handler = new(HttpRequestResult("{}"));
+        HttpRequestExecutor action = new(model, handler.Object, this._agentProvider.Object, this.State);
+
+        // Act
+        await this.ExecuteAsync(action);
+
+        // Assert
+        VerifyModel(model, action);
+        handler.VerifySent(info =>
+            info.Timeout is not null &&
+            info.Timeout.Value == TimeSpan.FromMilliseconds(1500));
+    }
+
+    [Fact]
+    public async Task HttpRequestTimeoutRaisesDeclarativeExceptionAsync()
+    {
+        // Arrange
+        this.State.InitializeSystem();
+        HttpRequestAction model = this.CreateModel(
+            displayName: nameof(HttpRequestTimeoutRaisesDeclarativeExceptionAsync),
+            url: TestUrl,
+            method: HttpMethodType.Get);
+
+        MockHttpRequestHandler handler = new(
+            HttpRequestResult("{}"),
+            throwOnSend: new OperationCanceledException());
+        HttpRequestExecutor action = new(model, handler.Object, this._agentProvider.Object, this.State);
+
+        // Act & Assert
+        await Assert.ThrowsAsync<DeclarativeActionException>(() => this.ExecuteAsync(action));
+    }
+
+    [Fact]
+    public async Task HttpRequestTransportFailureRaisesDeclarativeExceptionAsync()
+    {
+        // Arrange
+        this.State.InitializeSystem();
+        HttpRequestAction model = this.CreateModel(
+            displayName: nameof(HttpRequestTransportFailureRaisesDeclarativeExceptionAsync),
+            url: TestUrl,
+            method: HttpMethodType.Get);
+
+        MockHttpRequestHandler handler = new(
+            HttpRequestResult("{}"),
+            throwOnSend: new InvalidOperationException("transport failure"));
+        HttpRequestExecutor action = new(model, handler.Object, this._agentProvider.Object, this.State);
+
+        // Act & Assert
+        await Assert.ThrowsAsync<DeclarativeActionException>(() => this.ExecuteAsync(action));
+    }
+
+    [Fact]
+    public async Task HttpRequestStoresResponseHeadersAsync()
+    {
+        // Arrange
+        this.State.InitializeSystem();
+        const string HeaderVar = "Headers";
+        HttpRequestAction model = this.CreateModel(
+            displayName: nameof(HttpRequestStoresResponseHeadersAsync),
+            url: TestUrl,
+            method: HttpMethodType.Get,
+            responseHeadersVariable: HeaderVar);
+
+        Dictionary<string, IReadOnlyList<string>> responseHeaders = new(StringComparer.OrdinalIgnoreCase)
+        {
+            ["X-Request-Id"] = ["abc-123"],
+            ["Set-Cookie"] = ["a=1", "b=2"],
+        };
+        MockHttpRequestHandler handler = new(HttpRequestResult("{}", headers: responseHeaders));
+        HttpRequestExecutor action = new(model, handler.Object, this._agentProvider.Object, this.State);
+
+        // Act
+        await this.ExecuteAsync(action);
+
+        // Assert
+        VerifyModel(model, action);
+        FormulaValue storedHeaders = this.State.Get(HeaderVar);
+        Assert.IsType<RecordValue>(storedHeaders, exactMatch: false);
+    }
+
+    [Fact]
+    public async Task HttpRequestForwardsQueryParametersAsync()
+    {
+        // Arrange
+        this.State.InitializeSystem();
+        HttpRequestAction model = this.CreateModel(
+            displayName: nameof(HttpRequestForwardsQueryParametersAsync),
+            url: TestUrl,
+            method: HttpMethodType.Get,
+            queryParameters: new Dictionary<string, DataValue>
+            {
+                ["filter"] = StringDataValue.Create("active"),
+                ["limit"] = NumberDataValue.Create(10),
+                ["includeDeleted"] = BooleanDataValue.Create(false),
+            });
+
+        MockHttpRequestHandler handler = new(HttpRequestResult("{}"));
+        HttpRequestExecutor action = new(model, handler.Object, this._agentProvider.Object, this.State);
+
+        // Act
+        await this.ExecuteAsync(action);
+
+        // Assert
+        VerifyModel(model, action);
+        handler.VerifySent(info =>
+            info.QueryParameters?.Count == 3 &&
+            info.QueryParameters["filter"] == "active" &&
+            info.QueryParameters["limit"] == "10" &&
+            info.QueryParameters["includeDeleted"] == "false");
+    }
+
+    [Fact]
+    public async Task HttpRequestAddsResponseToConversationAsync()
+    {
+        // Arrange
+        this.State.InitializeSystem();
+        const string ConversationId = "conv-12345";
+        const string ResponseBody = "response-text";
+
+        this._agentProvider
+            .Setup(p => p.CreateMessageAsync(It.IsAny<string>(), It.IsAny<ChatMessage>(), It.IsAny<CancellationToken>()))
+            .Returns<string, ChatMessage, CancellationToken>((_, message, _) => Task.FromResult(message));
+
+        HttpRequestAction model = this.CreateModel(
+            displayName: nameof(HttpRequestAddsResponseToConversationAsync),
+            url: TestUrl,
+            method: HttpMethodType.Get,
+            conversationId: ConversationId);
+
+        MockHttpRequestHandler handler = new(HttpRequestResult(ResponseBody));
+        HttpRequestExecutor action = new(model, handler.Object, this._agentProvider.Object, this.State);
+
+        // Act
+        await this.ExecuteAsync(action);
+
+        // Assert
+        VerifyModel(model, action);
+        this._agentProvider.Verify(
+            p => p.CreateMessageAsync(
+                ConversationId,
+                It.Is<ChatMessage>(m => m.Role == ChatRole.Assistant && m.Text == ResponseBody),
+                It.IsAny<CancellationToken>()),
+            Times.Once);
+    }
+
+    [Fact]
+    public async Task HttpRequestWithoutConversationIdSkipsConversationAsync()
+    {
+        // Arrange
+        this.State.InitializeSystem();
+        HttpRequestAction model = this.CreateModel(
+            displayName: nameof(HttpRequestWithoutConversationIdSkipsConversationAsync),
+            url: TestUrl,
+            method: HttpMethodType.Get);
+
+        MockHttpRequestHandler handler = new(HttpRequestResult("response"));
+        HttpRequestExecutor action = new(model, handler.Object, this._agentProvider.Object, this.State);
+
+        // Act
+        await this.ExecuteAsync(action);
+
+        // Assert
+        VerifyModel(model, action);
+        this._agentProvider.Verify(
+            p => p.CreateMessageAsync(It.IsAny<string>(), It.IsAny<ChatMessage>(), It.IsAny<CancellationToken>()),
+            Times.Never);
+    }
+
+    [Fact]
+    public async Task HttpRequestForwardsConnectionNameAsync()
+    {
+        // Arrange
+        this.State.InitializeSystem();
+        const string ConnectionName = "my-connection";
+        HttpRequestAction model = this.CreateModel(
+            displayName: nameof(HttpRequestForwardsConnectionNameAsync),
+            url: TestUrl,
+            method: HttpMethodType.Get,
+            connectionName: ConnectionName);
+
+        MockHttpRequestHandler handler = new(HttpRequestResult("{}"));
+        HttpRequestExecutor action = new(model, handler.Object, this._agentProvider.Object, this.State);
+
+        // Act
+        await this.ExecuteAsync(action);
+
+        // Assert
+        VerifyModel(model, action);
+        handler.VerifySent(info => info.ConnectionName == ConnectionName);
+    }
+
+    [Fact]
+    public async Task HttpRequestEmptyConversationIdSkipsConversationAsync()
+    {
+        // Arrange - empty-string conversationId should be treated as unset.
+        this.State.InitializeSystem();
+        HttpRequestAction model = this.CreateModel(
+            displayName: nameof(HttpRequestEmptyConversationIdSkipsConversationAsync),
+            url: TestUrl,
+            method: HttpMethodType.Get,
+            conversationId: "");
+
+        MockHttpRequestHandler handler = new(HttpRequestResult("response"));
+        HttpRequestExecutor action = new(model, handler.Object, this._agentProvider.Object, this.State);
+
+        // Act
+        await this.ExecuteAsync(action);
+
+        // Assert
+        VerifyModel(model, action);
+        this._agentProvider.Verify(
+            p => p.CreateMessageAsync(It.IsAny<string>(), It.IsAny<ChatMessage>(), It.IsAny<CancellationToken>()),
+            Times.Never);
+    }
+
+    [Fact]
+    public async Task HttpRequestEmptyResponseBodySkipsConversationAsync()
+    {
+        // Arrange - conversationId set, but empty body should not produce a conversation message.
+        this.State.InitializeSystem();
+        HttpRequestAction model = this.CreateModel(
+            displayName: nameof(HttpRequestEmptyResponseBodySkipsConversationAsync),
+            url: TestUrl,
+            method: HttpMethodType.Get,
+            conversationId: "conv-1");
+
+        MockHttpRequestHandler handler = new(HttpRequestResult(""));
+        HttpRequestExecutor action = new(model, handler.Object, this._agentProvider.Object, this.State);
+
+        // Act
+        await this.ExecuteAsync(action);
+
+        // Assert
+        VerifyModel(model, action);
+        this._agentProvider.Verify(
+            p => p.CreateMessageAsync(It.IsAny<string>(), It.IsAny<ChatMessage>(), It.IsAny<CancellationToken>()),
+            Times.Never);
+    }
+
+    [Fact]
+    public async Task HttpGetReturnsJsonArrayAsync()
+    {
+        // Arrange - exercises JsonValueKind.Array branch of ParseResponseBody.
+        this.State.InitializeSystem();
+        const string ResponseVar = "Result";
+        HttpRequestAction model = this.CreateModel(
+            displayName: nameof(HttpGetReturnsJsonArrayAsync),
+            url: TestUrl,
+            method: HttpMethodType.Get,
+            responseVariable: ResponseVar);
+
+        MockHttpRequestHandler handler = new(HttpRequestResult("[1, 2, 3]"));
+        HttpRequestExecutor action = new(model, handler.Object, this._agentProvider.Object, this.State);
+
+        // Act
+        await this.ExecuteAsync(action);
+
+        // Assert
+        VerifyModel(model, action);
+        FormulaValue stored = this.State.Get(ResponseVar);
+        Assert.IsType<TableValue>(stored, exactMatch: false);
+    }
+
+    [Fact]
+    public async Task HttpGetWithEmptyHeaderValueDropsHeaderAsync()
+    {
+        // Arrange - empty header values should be filtered out (matches GetHeaders guard).
+        this.State.InitializeSystem();
+        HttpRequestAction model = this.CreateModel(
+            displayName: nameof(HttpGetWithEmptyHeaderValueDropsHeaderAsync),
+            url: TestUrl,
+            method: HttpMethodType.Get,
+            headers: new Dictionary<string, string>
+            {
+                ["X-Trace"] = "trace-1",
+                ["X-Empty"] = "",
+            });
+
+        MockHttpRequestHandler handler = new(HttpRequestResult("{}"));
+        HttpRequestExecutor action = new(model, handler.Object, this._agentProvider.Object, this.State);
+
+        // Act
+        await this.ExecuteAsync(action);
+
+        // Assert
+        VerifyModel(model, action);
+        handler.VerifySent(info =>
+            info.Headers?.ContainsKey("X-Trace") == true &&
+            info.Headers?.ContainsKey("X-Empty") == false);
+    }
+
+    [Fact]
+    public async Task HttpRequestZeroTimeoutNotForwardedAsync()
+    {
+        // Arrange - non-positive timeouts should not be forwarded (handler default applies).
+        this.State.InitializeSystem();
+        HttpRequestAction model = this.CreateModel(
+            displayName: nameof(HttpRequestZeroTimeoutNotForwardedAsync),
+            url: TestUrl,
+            method: HttpMethodType.Get,
+            timeoutMilliseconds: 0);
+
+        MockHttpRequestHandler handler = new(HttpRequestResult("{}"));
+        HttpRequestExecutor action = new(model, handler.Object, this._agentProvider.Object, this.State);
+
+        // Act
+        await this.ExecuteAsync(action);
+
+        // Assert
+        VerifyModel(model, action);
+        handler.VerifySent(info => info.Timeout is null);
+    }
+
+    private static HttpRequestResult HttpRequestResult(
+        string? body,
+        int statusCode = 200,
+        bool isSuccess = true,
+        IReadOnlyDictionary<string, IReadOnlyList<string>>? headers = null) =>
+        new()
+        {
+            StatusCode = statusCode,
+            IsSuccessStatusCode = isSuccess,
+            Body = body,
+            Headers = headers,
+        };
+
+    private HttpRequestAction CreateModel(
+        string displayName,
+        string url,
+        HttpMethodType method,
+        string? responseVariable = null,
+        string? responseHeadersVariable = null,
+        IReadOnlyDictionary<string, string>? headers = null,
+        IReadOnlyDictionary<string, DataValue>? queryParameters = null,
+        string? conversationId = null,
+        string? connectionName = null,
+        DataValue? jsonBody = null,
+        string? rawBody = null,
+        string? rawContentType = null,
+        long? timeoutMilliseconds = null,
+        string? continueOnErrorStatusVariable = null,
+        string? continueOnErrorBodyVariable = null)
+    {
+        HttpRequestAction.Builder builder = new()
+        {
+            Id = this.CreateActionId(),
+            DisplayName = this.FormatDisplayName(displayName),
+            Url = new StringExpression.Builder(StringExpression.Literal(url)),
+            Method = new EnumExpression<HttpMethodTypeWrapper>.Builder(
+                EnumExpression<HttpMethodTypeWrapper>.Literal(HttpMethodTypeWrapper.Get(method))),
+        };
+
+        if (responseVariable is not null)
+        {
+            builder.Response = PropertyPath.Create(FormatVariablePath(responseVariable));
+        }
+
+        if (responseHeadersVariable is not null)
+        {
+            builder.ResponseHeaders = PropertyPath.Create(FormatVariablePath(responseHeadersVariable));
+        }
+
+        if (headers is not null)
+        {
+            foreach (KeyValuePair<string, string> header in headers)
+            {
+                builder.Headers.Add(header.Key, new StringExpression.Builder(StringExpression.Literal(header.Value)));
+            }
+        }
+
+        if (queryParameters is not null)
+        {
+            foreach (KeyValuePair<string, DataValue> parameter in queryParameters)
+            {
+                builder.QueryParameters.Add(parameter.Key, new ValueExpression.Builder(ValueExpression.Literal(parameter.Value)));
+            }
+        }
+
+        if (conversationId is not null)
+        {
+            builder.ConversationId = new StringExpression.Builder(StringExpression.Literal(conversationId));
+        }
+
+        if (connectionName is not null)
+        {
+            builder.Connection = new RemoteConnection.Builder
+            {
+                Name = new StringExpression.Builder(StringExpression.Literal(connectionName)),
+            };
+        }
+
+        if (jsonBody is not null)
+        {
+            builder.Body = new JsonRequestContent.Builder()
+            {
+                Content = new ValueExpression.Builder(ValueExpression.Literal(jsonBody)),
+            };
+        }
+        else if (rawBody is not null)
+        {
+            RawRequestContent.Builder rawBuilder = new()
+            {
+                Content = new StringExpression.Builder(StringExpression.Literal(rawBody)),
+            };
+            if (rawContentType is not null)
+            {
+                rawBuilder.ContentType = new StringExpression.Builder(StringExpression.Literal(rawContentType));
+            }
+            builder.Body = rawBuilder;
+        }
+
+        if (timeoutMilliseconds is not null)
+        {
+            builder.RequestTimeoutInMilliseconds = new IntExpression.Builder(IntExpression.Literal(timeoutMilliseconds.Value));
+        }
+
+        if (continueOnErrorStatusVariable is not null || continueOnErrorBodyVariable is not null)
+        {
+            ContinueOnErrorBehavior.Builder continueBuilder = new();
+            if (continueOnErrorStatusVariable is not null)
+            {
+                continueBuilder.StatusCode = PropertyPath.Create(FormatVariablePath(continueOnErrorStatusVariable));
+            }
+            if (continueOnErrorBodyVariable is not null)
+            {
+                continueBuilder.ErrorResponseBody = PropertyPath.Create(FormatVariablePath(continueOnErrorBodyVariable));
+            }
+            builder.ErrorHandling = continueBuilder;
+        }
+
+        return AssignParent<HttpRequestAction>(builder);
+    }
+
+    private sealed class MockHttpRequestHandler : Mock<IHttpRequestHandler>
+    {
+        private HttpRequestInfo? _lastRequest;
+
+        public MockHttpRequestHandler(HttpRequestResult result, Exception? throwOnSend = null)
+        {
+            this.Setup(handler => handler.SendAsync(It.IsAny<HttpRequestInfo>(), It.IsAny<CancellationToken>()))
+                .Returns<HttpRequestInfo, CancellationToken>((info, _) =>
+                {
+                    this._lastRequest = info;
+                    if (throwOnSend is not null)
+                    {
+                        throw throwOnSend;
+                    }
+                    return Task.FromResult(result);
+                });
+        }
+
+        public void VerifySent(Func<HttpRequestInfo, bool> predicate)
+        {
+            Assert.NotNull(this._lastRequest);
+            Assert.True(predicate(this._lastRequest!), "Sent HTTP request did not match expected predicate.");
+        }
+    }
+}

dotnet/tests/Microsoft.Agents.AI.Workflows.Declarative.UnitTests/Workflows/HttpRequest.yaml

@@ -0,0 +1,15 @@
+kind: Workflow
+trigger:
+
+  kind: OnConversationStart
+  id: my_workflow
+  actions:
+
+    - kind: HttpRequestAction
+      id: http_request
+      method: GET
+      url: =Concatenate("https://api.example.test/items/", System.LastMessageText)
+      headers:
+        Accept: application/json
+      response: Local.HttpResult
+      responseHeaders: Local.HttpHeaders