diff --git a/dotnet/src/AutoGen.OpenAI/AutoGen.OpenAI.csproj b/dotnet/src/AutoGen.OpenAI/AutoGen.OpenAI.csproj
index 7f00b63be86c..70c0f2b0d1ce 100644
--- a/dotnet/src/AutoGen.OpenAI/AutoGen.OpenAI.csproj
+++ b/dotnet/src/AutoGen.OpenAI/AutoGen.OpenAI.csproj
@@ -18,6 +18,7 @@
 
   <ItemGroup>
     <PackageReference Include="OpenAI" Version="$(OpenAISDKVersion)" />
+    <ProjectReference Include="..\AutoGen.SourceGenerator\AutoGen.SourceGenerator.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/dotnet/src/AutoGen.OpenAI/Orchestrator/RolePlayToolCallOrchestrator.cs b/dotnet/src/AutoGen.OpenAI/Orchestrator/RolePlayToolCallOrchestrator.cs
new file mode 100644
index 000000000000..f088e1748e66
--- /dev/null
+++ b/dotnet/src/AutoGen.OpenAI/Orchestrator/RolePlayToolCallOrchestrator.cs
@@ -0,0 +1,133 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// RolePlayToolCallOrchestrator.cs
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using AutoGen.OpenAI.Extension;
+using OpenAI.Chat;
+
+namespace AutoGen.OpenAI.Orchestrator;
+
+/// <summary>
+/// Orchestrating group chat using role play tool call
+/// </summary>
+public partial class RolePlayToolCallOrchestrator : IOrchestrator
+{
+    public readonly ChatClient chatClient;
+    private readonly Graph? workflow;
+
+    public RolePlayToolCallOrchestrator(ChatClient chatClient, Graph? workflow = null)
+    {
+        this.chatClient = chatClient;
+        this.workflow = workflow;
+    }
+
+    public async Task<IAgent?> GetNextSpeakerAsync(
+        OrchestrationContext context,
+        CancellationToken cancellationToken = default)
+    {
+        var candidates = context.Candidates.ToList();
+
+        if (candidates.Count == 0)
+        {
+            return null;
+        }
+
+        if (candidates.Count == 1)
+        {
+            return candidates.First();
+        }
+
+        // if there's a workflow
+        // and the next available agent from the workflow is in the group chat
+        // then return the next agent from the workflow
+        if (this.workflow != null)
+        {
+            var lastMessage = context.ChatHistory.LastOrDefault();
+            if (lastMessage == null)
+            {
+                return null;
+            }
+            var currentSpeaker = candidates.First(candidates => candidates.Name == lastMessage.From);
+            var nextAgents = await this.workflow.TransitToNextAvailableAgentsAsync(currentSpeaker, context.ChatHistory, cancellationToken);
+            nextAgents = nextAgents.Where(nextAgent => candidates.Any(candidate => candidate.Name == nextAgent.Name));
+            candidates = nextAgents.ToList();
+            if (!candidates.Any())
+            {
+                return null;
+            }
+
+            if (candidates is { Count: 1 })
+            {
+                return candidates.First();
+            }
+        }
+
+        // In this case, since there are more than one available agents from the workflow for the next speaker
+        // We need to invoke LLM to select the next speaker via select next speaker function
+
+        var chatHistoryStringBuilder = new StringBuilder();
+        foreach (var message in context.ChatHistory)
+        {
+            var chatHistoryPrompt = $"{message.From}: {message.GetContent()}";
+
+            chatHistoryStringBuilder.AppendLine(chatHistoryPrompt);
+        }
+
+        var chatHistory = chatHistoryStringBuilder.ToString();
+
+        var prompt = $"""
+            # Task: Select the next speaker
+
+            You are in a role-play game. Carefully read the conversation history and select the next speaker from the available roles.
+
+            # Conversation
+            {chatHistory}
+
+            # Available roles
+            - {string.Join(",", candidates.Select(candidate => candidate.Name))}
+
+            Select the next speaker from the available roles and provide a reason for your selection.
+            """;
+
+        // enforce the next speaker to be selected by the LLM
+        var option = new ChatCompletionOptions
+        {
+            ToolChoice = ChatToolChoice.CreateFunctionChoice(this.SelectNextSpeakerFunctionContract.Name),
+        };
+
+        option.Tools.Add(this.SelectNextSpeakerFunctionContract.ToChatTool());
+        var toolCallMiddleware = new FunctionCallMiddleware(
+            functions: [this.SelectNextSpeakerFunctionContract],
+            functionMap: new Dictionary<string, Func<string, Task<string>>>
+            {
+                [this.SelectNextSpeakerFunctionContract.Name] = this.SelectNextSpeakerWrapper,
+            });
+
+        var selectAgent = new OpenAIChatAgent(
+            chatClient,
+            "admin",
+            option)
+            .RegisterMessageConnector()
+            .RegisterMiddleware(toolCallMiddleware);
+
+        var reply = await selectAgent.SendAsync(prompt);
+
+        var nextSpeaker = candidates.FirstOrDefault(candidate => candidate.Name == reply.GetContent());
+
+        return nextSpeaker;
+    }
+
+    /// <summary>
+    /// Select the next speaker by name and reason
+    /// </summary>
+    [Function]
+    public async Task<string> SelectNextSpeaker(string name, string reason)
+    {
+        return name;
+    }
+}
diff --git a/dotnet/test/AutoGen.OpenAI.Tests/RolePlayToolCallOrchestratorTests.cs b/dotnet/test/AutoGen.OpenAI.Tests/RolePlayToolCallOrchestratorTests.cs
new file mode 100644
index 000000000000..807bf41e9479
--- /dev/null
+++ b/dotnet/test/AutoGen.OpenAI.Tests/RolePlayToolCallOrchestratorTests.cs
@@ -0,0 +1,269 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// RolePlayToolCallOrchestratorTests.cs
+
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using AutoGen.OpenAI.Orchestrator;
+using AutoGen.Tests;
+using Azure.AI.OpenAI;
+using FluentAssertions;
+using Moq;
+using OpenAI;
+using OpenAI.Chat;
+using Xunit;
+
+namespace AutoGen.OpenAI.Tests;
+
+public class RolePlayToolCallOrchestratorTests
+{
+    [Fact]
+    public async Task ItReturnNullWhenNoCandidateIsAvailableAsync()
+    {
+        var chatClient = Mock.Of<ChatClient>();
+        var orchestrator = new RolePlayToolCallOrchestrator(chatClient);
+        var context = new OrchestrationContext
+        {
+            Candidates = [],
+            ChatHistory = [],
+        };
+
+        var speaker = await orchestrator.GetNextSpeakerAsync(context);
+        speaker.Should().BeNull();
+    }
+
+    [Fact]
+    public async Task ItReturnCandidateWhenOnlyOneCandidateIsAvailableAsync()
+    {
+        var chatClient = Mock.Of<ChatClient>();
+        var alice = new EchoAgent("Alice");
+        var orchestrator = new RolePlayToolCallOrchestrator(chatClient);
+        var context = new OrchestrationContext
+        {
+            Candidates = [alice],
+            ChatHistory = [],
+        };
+
+        var speaker = await orchestrator.GetNextSpeakerAsync(context);
+        speaker.Should().Be(alice);
+    }
+
+    [Fact]
+    public async Task ItSelectNextSpeakerFromWorkflowIfProvided()
+    {
+        var workflow = new Graph();
+        var alice = new EchoAgent("Alice");
+        var bob = new EchoAgent("Bob");
+        var charlie = new EchoAgent("Charlie");
+        workflow.AddTransition(Transition.Create(alice, bob));
+        workflow.AddTransition(Transition.Create(bob, charlie));
+        workflow.AddTransition(Transition.Create(charlie, alice));
+
+        var client = Mock.Of<ChatClient>();
+        var orchestrator = new RolePlayToolCallOrchestrator(client, workflow);
+        var context = new OrchestrationContext
+        {
+            Candidates = [alice, bob, charlie],
+            ChatHistory =
+            [
+                new TextMessage(Role.User, "Hello, Bob", from: "Alice"),
+            ],
+        };
+
+        var speaker = await orchestrator.GetNextSpeakerAsync(context);
+        speaker.Should().Be(bob);
+    }
+
+    [Fact]
+    public async Task ItReturnNullIfNoAvailableAgentFromWorkflowAsync()
+    {
+        var workflow = new Graph();
+        var alice = new EchoAgent("Alice");
+        var bob = new EchoAgent("Bob");
+        workflow.AddTransition(Transition.Create(alice, bob));
+
+        var client = Mock.Of<ChatClient>();
+        var orchestrator = new RolePlayToolCallOrchestrator(client, workflow);
+        var context = new OrchestrationContext
+        {
+            Candidates = [alice, bob],
+            ChatHistory =
+            [
+                new TextMessage(Role.User, "Hello, Alice", from: "Bob"),
+            ],
+        };
+
+        var speaker = await orchestrator.GetNextSpeakerAsync(context);
+        speaker.Should().BeNull();
+    }
+
+    [ApiKeyFact("AZURE_OPENAI_API_KEY", "AZURE_OPENAI_ENDPOINT", "AZURE_OPENAI_DEPLOY_NAME")]
+    public async Task GPT_3_5_CoderReviewerRunnerTestAsync()
+    {
+        var endpoint = Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT") ?? throw new Exception("Please set AZURE_OPENAI_ENDPOINT environment variable.");
+        var key = Environment.GetEnvironmentVariable("AZURE_OPENAI_API_KEY") ?? throw new Exception("Please set AZURE_OPENAI_API_KEY environment variable.");
+        var deployName = Environment.GetEnvironmentVariable("AZURE_OPENAI_DEPLOY_NAME") ?? throw new Exception("Please set AZURE_OPENAI_DEPLOY_NAME environment variable.");
+        var openaiClient = new AzureOpenAIClient(new Uri(endpoint), new System.ClientModel.ApiKeyCredential(key));
+        var chatClient = openaiClient.GetChatClient(deployName);
+
+        await BusinessWorkflowTest(chatClient);
+        await CoderReviewerRunnerTestAsync(chatClient);
+    }
+
+    [ApiKeyFact("OPENAI_API_KEY")]
+    public async Task GPT_4o_CoderReviewerRunnerTestAsync()
+    {
+        var apiKey = Environment.GetEnvironmentVariable("OPENAI_API_KEY") ?? throw new InvalidOperationException("OPENAI_API_KEY is not set");
+        var model = "gpt-4o";
+        var openaiClient = new OpenAIClient(apiKey);
+        var chatClient = openaiClient.GetChatClient(model);
+
+        await BusinessWorkflowTest(chatClient);
+        await CoderReviewerRunnerTestAsync(chatClient);
+    }
+
+    [ApiKeyFact("OPENAI_API_KEY")]
+    public async Task GPT_4o_mini_CoderReviewerRunnerTestAsync()
+    {
+        var apiKey = Environment.GetEnvironmentVariable("OPENAI_API_KEY") ?? throw new InvalidOperationException("OPENAI_API_KEY is not set");
+        var model = "gpt-4o-mini";
+        var openaiClient = new OpenAIClient(apiKey);
+        var chatClient = openaiClient.GetChatClient(model);
+
+        await BusinessWorkflowTest(chatClient);
+        await CoderReviewerRunnerTestAsync(chatClient);
+    }
+
+    /// <summary>
+    /// This test is to mimic the conversation among coder, reviewer and runner.
+    /// The coder will write the code, the reviewer will review the code, and the runner will run the code.
+    /// </summary>
+    /// <param name="client"></param>
+    /// <returns></returns>
+    private async Task CoderReviewerRunnerTestAsync(ChatClient client)
+    {
+        var coder = new EchoAgent("Coder");
+        var reviewer = new EchoAgent("Reviewer");
+        var runner = new EchoAgent("Runner");
+        var user = new EchoAgent("User");
+        var initializeMessage = new List<IMessage>
+        {
+            new TextMessage(Role.User, "Hello, I am user, I will provide the coding task, please write the code first, then review and run it", from: "User"),
+            new TextMessage(Role.User, "Hello, I am coder, I will write the code", from: "Coder"),
+            new TextMessage(Role.User, "Hello, I am reviewer, I will review the code", from: "Reviewer"),
+            new TextMessage(Role.User, "Hello, I am runner, I will run the code", from: "Runner"),
+            new TextMessage(Role.User, "how to print 'hello world' using C#", from: user.Name),
+        };
+
+        var chatHistory = new List<IMessage>()
+        {
+            new TextMessage(Role.User, """
+            ```csharp
+            Console.WriteLine("Hello World");
+            ```
+            """, from: coder.Name),
+            new TextMessage(Role.User, "The code looks good", from: reviewer.Name),
+            new TextMessage(Role.User, "The code runs successfully, the output is 'Hello World'", from: runner.Name),
+        };
+
+        var orchestrator = new RolePlayToolCallOrchestrator(client);
+        foreach (var message in chatHistory)
+        {
+            var context = new OrchestrationContext
+            {
+                Candidates = [coder, reviewer, runner, user],
+                ChatHistory = initializeMessage,
+            };
+
+            var speaker = await orchestrator.GetNextSpeakerAsync(context);
+            speaker!.Name.Should().Be(message.From);
+            initializeMessage.Add(message);
+        }
+
+        // the last next speaker should be the user
+        var lastSpeaker = await orchestrator.GetNextSpeakerAsync(new OrchestrationContext
+        {
+            Candidates = [coder, reviewer, runner, user],
+            ChatHistory = initializeMessage,
+        });
+
+        lastSpeaker!.Name.Should().Be(user.Name);
+    }
+
+    // test if the tool call orchestrator still run business workflow when the conversation is not in English
+    private async Task BusinessWorkflowTest(ChatClient client)
+    {
+        var ceo = new EchoAgent("乙方首席执行官");
+        var pm = new EchoAgent("乙方项目经理");
+        var dev = new EchoAgent("乙方开发人员");
+        var user = new EchoAgent("甲方");
+        var initializeMessage = new List<IMessage>
+        {
+            new TextMessage(Role.User, "你好，我是你们的甲方", from: user.Name),
+            new TextMessage(Role.User, "你好，我是乙方首席执行官，我将负责对接甲方和给项目经理及开发人员分配任务", from: ceo.Name),
+            new TextMessage(Role.User, "你好，我是乙方项目经理，我将负责项目的进度和质量", from: pm.Name),
+            new TextMessage(Role.User, "你好，我是乙方开发人员 我将负责项目的具体开发", from: dev.Name),
+            new TextMessage(Role.User, "开发一个淘宝，预算1W", from: user.Name),
+        };
+
+        var workflow = new Graph();
+        workflow.AddTransition(Transition.Create(ceo, pm));
+        workflow.AddTransition(Transition.Create(ceo, dev));
+        workflow.AddTransition(Transition.Create(pm, ceo));
+        workflow.AddTransition(Transition.Create(dev, ceo));
+        workflow.AddTransition(Transition.Create(user, ceo));
+        workflow.AddTransition(Transition.Create(ceo, user));
+
+        var chatHistory = new List<IMessage>()
+        {
+            new TextMessage(Role.User, """
+            项目经理，如何使用1W预算开发一个淘宝
+            """, from: ceo.Name),
+            new TextMessage(Role.User, """
+            对于1万预算开发淘宝类网站,以下是关键建议:
+            技术选择:
+            - 使用开源电商系统节省成本, 选择便宜但稳定的云服务器和域名,预算2000元/年
+            - 核心功能优先
+            - 人员安排:
+             - 找1位全栈开发,负责系统搭建(6000元)
+             - 1位兼职UI设计(2000元)
+            - 进度规划:
+             - 基础功能1个月完成,后续根据运营情况逐步优化。
+            """, from: pm.Name),
+            new TextMessage(Role.User, "好的，开发人员，请根据项目经理的规划开始开发", from: ceo.Name),
+            new TextMessage(Role.User, """
+            好的，已开发完毕
+            ```html
+            <button class="taobao-button" onclick="window.location.href='https://www.taobao.com'">
+                Visit Taobao
+            </button>
+            ```
+            """, from: dev.Name),
+            new TextMessage(Role.User, "好的，项目已完成，甲方请付款", from: ceo.Name),
+        };
+
+        var orchestrator = new RolePlayToolCallOrchestrator(client, workflow);
+
+        foreach (var message in chatHistory)
+        {
+            var context = new OrchestrationContext
+            {
+                Candidates = [ceo, pm, dev, user],
+                ChatHistory = initializeMessage,
+            };
+
+            var speaker = await orchestrator.GetNextSpeakerAsync(context);
+            speaker!.Name.Should().Be(message.From);
+            initializeMessage.Add(message);
+        }
+
+        // the last next speaker should be the user
+        var lastSpeaker = await orchestrator.GetNextSpeakerAsync(new OrchestrationContext
+        {
+            Candidates = [ceo, pm, dev, user],
+            ChatHistory = initializeMessage,
+        });
+
+        lastSpeaker!.Name.Should().Be(user.Name);
+    }
+}