New MCP server quickstart

docs/ai/quickstarts/build-mcp-server.md

@@ -0,0 +1,113 @@
+---
+title: Quickstart - Create a minimal MCP Server using .NET
+description: Learn to create and connect to a minimal MCP server using .NET
+ms.date: 05/21/2025
+ms.topic: quickstart
+ms.custom: devx-track-dotnet, devx-track-dotnet-ai
+author: alexwolfmsft
+ms.author: alexwolf
+---
+
+# Create and connect to a minimal MCP server using .NET
+
+In this quickstart, you create a minimal Model Context Protocol (MCP) server using the [C# SDK for MCP](https://github.com/modelcontextprotocol/csharp-sdk) and connect to it using GitHub Copilot. MCP servers are services that expose capabilities to clients through the Model Context Protocol (MCP).
+
+## Prerequisites
+
+- [.NET 8.0 SDK or higher](https://dotnet.microsoft.com/download)
+- [Visual Studio Code](https://code.visualstudio.com/)
+- [GitHub Copilot extension](https://marketplace.visualstudio.com/items?itemName=GitHub.copilot) for Visual Studio Code
+
+## Create the project
+
+1. In a terminal window, navigate to the directory where you want to create your app, and create a new console app with the `dotnet new` command:
+
+   ```bash
+   dotnet new console -n MinimalMcpServer
+   ```
+
+1. Navigate to the `MinimalMcpServer` directory:
+
+   ```bash
+   cd MinimalMcpServer
+   ```
+
+1. Add the following NuGet packages to your app:
+
+   ```bash
+   dotnet add package ModelContextProtocol --prerelease
+   dotnet add package Microsoft.Extensions.Hosting
+   ```
+
+    - The [ModelContextProtocol](https://www.nuget.org/packages/ModelContextProtocol) package is the official C# SDK for working with the Model Context Protocol.
+    - The [Microsoft.Extensions.Hosting](https://www.nuget.org/packages/Microsoft.Extensions.Hosting) package provides the generic .NET `HostBuilder` and services for logging and dependency injection.
+
+## Add the app code
+
+Replace the contents of `Program.cs` with the following code to implement a minimal MCP server that exposes simple echo tools. The AI model invokes these tools as necessary to generate responses to user prompts.
+
+:::code language="csharp" source="snippets/mcp-server/program.cs" :::
+
+The preceding code:
+
+- Creates a generic host builder for dependency injection, logging, and configuration.
+- Configures logging for better integration with MCP clients.
+- Registers the MCP server, configures it to use stdio transport, and scans the assembly for tool definitions.
+- Builds and runs the host, which starts the MCP server.
+- Defines a static class to hold two MCP tools that echo values back to the client.
+
+## Configure the MCP server in Visual Studio Code
+
+Configure GitHub Copilot for Visual Studio Code to use your custom MCP server:
+
+1. If you haven't already, open your project folder in Visual Studio Code.
+1. Create a `.vscode` folder at the root of your project.
+1. Add an `mcp.json` file in the `.vscode` folder with the following content:
+
+   ```json
+   {
+     "inputs": [],
+     "servers": {
+       "MinimalMcpServer": {
+         "type": "stdio",
+         "command": "dotnet",
+         "args": [
+           "run",
+           "--project",
+           "${workspaceFolder}/MinimalMcpServer.csproj"
+         ]
+       }
+     }
+   }
+   ```
+
+1. Save the file.
+
+## Test the MCP server
+
+1. Open GitHub Copilot in Visual Studio Code and switch to agent mode.
+1. Select the **Select tools** icon to verify your **MinimalMcpServer** is available with both tools listed.
+
+    :::image type="content" source="../media/mcp/available-tools.png" alt-text="A screenshot showing the available MCP tools.":::
+
+1. Enter a prompt to run the **ReverseEcho** tool:
+
+    ```console
+    Reverse the following: "Hello, minimal MCP server!"
+    ```
+
+1. GitHub Copilot requests permission to run the **ReverseEcho** tool for your prompt. Select **Continue** or use the arrow to select a more specific behavior:
+
+    - **Current session** always runs the operation in the current GitHub Copilot Agent Mode session.
+    - **Current workspace** always runs the command for the current Visual Studio Code workspace.
+    - **Always allow** sets the operation to always run for any GitHub Copilot Agent Mode session or any Visual Studio Code workspace.
+
+1. Verify that the server responds with the echoed message:
+
+    ```output
+    !revres PCM laminim ,olleH
+    ```
+
+## Related content
+
+[Get started with .NET AI and the Model Context Protocol](../get-started-mcp.md)

docs/ai/quickstarts/snippets/mcp-server/MinimalMcpServer.csproj

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+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net9.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.Hosting" Version="9.0.5" />
+    <PackageReference Include="ModelContextProtocol" Version="0.2.0-preview.1" />
+  </ItemGroup>
+
+</Project>

docs/ai/quickstarts/snippets/mcp-server/Program.cs

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+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+using ModelContextProtocol.Server;
+using System.ComponentModel;
+
+// Create a generic host builder for
+// dependency injection, logging, and configuration.
+var builder = Host.CreateApplicationBuilder(args);
+
+// Configure logging for better integration with MCP clients.
+builder.Logging.AddConsole(consoleLogOptions =>
+{
+consoleLogOptions.LogToStandardErrorThreshold = LogLevel.Trace;
+});
+
+// Register the MCP server and configure it to use stdio transport.
+// Scan the assembly for tool definitions.
+builder.Services
+    .AddMcpServer()
+    .WithStdioServerTransport()
+    .WithToolsFromAssembly();
+
+// Build and run the host. This starts the MCP server.
+await builder.Build().RunAsync();
+
+// Define a static class to hold MCP tools.
+[McpServerToolType]
+public static class EchoTool
+{
+    // Expose a tool that echoes the input message back to the client.
+    [McpServerTool, Description("Echoes the message back to the client.")]
+    public static string Echo(string message) => $"Hello from C#: {message}";
+
+    // Expose a tool that returns the input message in reverse.
+    [McpServerTool, Description("Echoes in reverse the message sent by the client.")]
+    public static string ReverseEcho(string message) => new string(message.Reverse().ToArray());
+}

docs/ai/toc.yml

@@ -33,6 +33,8 @@ items:
     href: quickstarts/create-assistant.md
   - name: Get started using the AI app templates
     href: quickstarts/ai-templates.md
+  - name: Build a minimal MCP server
+    href: quickstarts/build-mcp-server.md
 - name: Concepts
   items:
   - name: How generative AI and LLMs work