Merge branch 'main' into feature-harness

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