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‎docs/ai/media/mcp/available-tools.png

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

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---
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title: Quickstart - Create a minimal MCP Server using .NET
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description: Learn to create and connect to a minimal MCP server using .NET
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ms.date: 05/21/2025
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ms.topic: quickstart
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ms.custom: devx-track-dotnet, devx-track-dotnet-ai
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author: alexwolfmsft
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ms.author: alexwolf
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---
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# Create and connect to a minimal MCP server using .NET
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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).
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## Prerequisites
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- [.NET 8.0 SDK or higher](https://dotnet.microsoft.com/download)
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- [Visual Studio Code](https://code.visualstudio.com/)
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- [GitHub Copilot extension](https://marketplace.visualstudio.com/items?itemName=GitHub.copilot) for Visual Studio Code
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## Create the project
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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:
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```bash
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dotnet new console -n MinimalMcpServer
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```
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1. Navigate to the `MinimalMcpServer` directory:
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```bash
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cd MinimalMcpServer
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```
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1. Add the following NuGet packages to your app:
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```bash
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dotnet add package ModelContextProtocol --prerelease
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dotnet add package Microsoft.Extensions.Hosting
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```
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- The [ModelContextProtocol](https://www.nuget.org/packages/ModelContextProtocol) package is the official C# SDK for working with the Model Context Protocol.
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- 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.
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## Add the app code
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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.
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:::code language="csharp" source="snippets/mcp-server/program.cs" :::
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The preceding code:
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- Creates a generic host builder for dependency injection, logging, and configuration.
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- Configures logging for better integration with MCP clients.
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- Registers the MCP server, configures it to use stdio transport, and scans the assembly for tool definitions.
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- Builds and runs the host, which starts the MCP server.
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- Defines a static class to hold two MCP tools that echo values back to the client.
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## Configure the MCP server in Visual Studio Code
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Configure GitHub Copilot for Visual Studio Code to use your custom MCP server:
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1. If you haven't already, open your project folder in Visual Studio Code.
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1. Create a `.vscode` folder at the root of your project.
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1. Add an `mcp.json` file in the `.vscode` folder with the following content:
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```json
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{
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"inputs": [],
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"servers": {
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"MinimalMcpServer": {
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"type": "stdio",
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"command": "dotnet",
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"args": [
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"run",
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"--project",
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"${workspaceFolder}/MinimalMcpServer.csproj"
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]
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}
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}
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}
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```
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1. Save the file.
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## Test the MCP server
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1. Open GitHub Copilot in Visual Studio Code and switch to agent mode.
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1. Select the **Select tools** icon to verify your **MinimalMcpServer** is available with both tools listed.
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:::image type="content" source="../media/mcp/available-tools.png" alt-text="A screenshot showing the available MCP tools.":::
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1. Enter a prompt to run the **ReverseEcho** tool:
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```console
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Reverse the following: "Hello, minimal MCP server!"
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```
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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:
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- **Current session** always runs the operation in the current GitHub Copilot Agent Mode session.
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- **Current workspace** always runs the command for the current Visual Studio Code workspace.
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- **Always allow** sets the operation to always run for any GitHub Copilot Agent Mode session or any Visual Studio Code workspace.
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1. Verify that the server responds with the echoed message:
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```output
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!revres PCM laminim ,olleH
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```
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## Related content
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[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">
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<PropertyGroup>
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<OutputType>Exe</OutputType>
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<TargetFramework>net9.0</TargetFramework>
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<ImplicitUsings>enable</ImplicitUsings>
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<Nullable>enable</Nullable>
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</PropertyGroup>
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<ItemGroup>
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<PackageReference Include="Microsoft.Extensions.Hosting" Version="9.0.5" />
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<PackageReference Include="ModelContextProtocol" Version="0.2.0-preview.1" />
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</ItemGroup>
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</Project>

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

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

‎docs/ai/toc.yml

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

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