Create a project template for an MCP server

src/ProjectTemplates/GeneratedContent.targets

@@ -10,6 +10,7 @@
     <_LocalChatTemplateVariant>aspire</_LocalChatTemplateVariant>
 
     <_ChatWithCustomDataContentRoot>$(MSBuildThisFileDirectory)Microsoft.Extensions.AI.Templates\src\ChatWithCustomData\</_ChatWithCustomDataContentRoot>
+    <_McpServerContentRoot>$(MSBuildThisFileDirectory)Microsoft.Extensions.AI.Templates\src\McpServer\</_McpServerContentRoot>
   </PropertyGroup>
 
   <Target Name="ComputeGeneratedContentProperties">
@@ -34,9 +35,11 @@
       <TemplatePackageVersion_AzureIdentity>1.14.0</TemplatePackageVersion_AzureIdentity>
       <TemplatePackageVersion_AzureSearchDocuments>11.6.0</TemplatePackageVersion_AzureSearchDocuments>
       <TemplatePackageVersion_CommunityToolkitAspire>9.4.1-beta.291</TemplatePackageVersion_CommunityToolkitAspire>
+      <TemplatePackageVersion_MicrosoftExtensionsHosting>10.0.0-preview.5.25277.114</TemplatePackageVersion_MicrosoftExtensionsHosting>
       <TemplatePackageVersion_MicrosoftExtensionsServiceDiscovery>9.3.0</TemplatePackageVersion_MicrosoftExtensionsServiceDiscovery>
       <TemplatePackageVersion_MicrosoftSemanticKernel>1.53.0</TemplatePackageVersion_MicrosoftSemanticKernel>
       <TemplatePackageVersion_MicrosoftSemanticKernel_Preview>1.53.0-preview</TemplatePackageVersion_MicrosoftSemanticKernel_Preview>
+      <TemplatePackageVersion_ModelContextProtocol>0.3.0-preview.1</TemplatePackageVersion_ModelContextProtocol>
       <TemplatePackageVersion_OllamaSharp>5.1.18</TemplatePackageVersion_OllamaSharp>
       <TemplatePackageVersion_OpenTelemetry>1.12.0</TemplatePackageVersion_OpenTelemetry>
       <TemplatePackageVersion_PdfPig>0.1.10</TemplatePackageVersion_PdfPig>
@@ -64,9 +67,11 @@
         TemplatePackageVersion_AzureIdentity=$(TemplatePackageVersion_AzureIdentity);
         TemplatePackageVersion_AzureSearchDocuments=$(TemplatePackageVersion_AzureSearchDocuments);
         TemplatePackageVersion_CommunityToolkitAspire=$(TemplatePackageVersion_CommunityToolkitAspire);
+        TemplatePackageVersion_MicrosoftExtensionsHosting=$(TemplatePackageVersion_MicrosoftExtensionsHosting);
         TemplatePackageVersion_MicrosoftExtensionsServiceDiscovery=$(TemplatePackageVersion_MicrosoftExtensionsServiceDiscovery);
         TemplatePackageVersion_MicrosoftSemanticKernel=$(TemplatePackageVersion_MicrosoftSemanticKernel);
         TemplatePackageVersion_MicrosoftSemanticKernel_Preview=$(TemplatePackageVersion_MicrosoftSemanticKernel_Preview);
+        TemplatePackageVersion_ModelContextProtocol=$(TemplatePackageVersion_ModelContextProtocol);
         TemplatePackageVersion_OllamaSharp=$(TemplatePackageVersion_OllamaSharp);
         TemplatePackageVersion_OpenTelemetry=$(TemplatePackageVersion_OpenTelemetry);
         TemplatePackageVersion_PdfPig=$(TemplatePackageVersion_PdfPig);
@@ -100,6 +105,9 @@
       <GeneratedContent
         Include="$(_ChatWithCustomDataContentRoot)ChatWithCustomData-CSharp.ServiceDefaults\ChatWithCustomData-CSharp.ServiceDefaults.csproj.in"
         OutputPath="$(_ChatWithCustomDataContentRoot)ChatWithCustomData-CSharp.ServiceDefaults\ChatWithCustomData-CSharp.ServiceDefaults.csproj" />
+      <GeneratedContent
+        Include="$(_McpServerContentRoot)McpServer-CSharp\McpServer-CSharp.csproj.in"
+        OutputPath="$(_McpServerContentRoot)McpServer-CSharp\McpServer-CSharp.csproj" />
 
       <!-- The following content only gets generated when using just-built packages -->
       <_GeneratedContentEnablingJustBuiltPackages

src/ProjectTemplates/Microsoft.Extensions.AI.Templates/Microsoft.Extensions.AI.Templates.csproj

@@ -61,6 +61,16 @@
         **\NuGet.config;
         **\Directory.Build.targets;
         **\Directory.Build.props;" />
+
+    <!-- Keep the exclude patterns below in sync with those in McpServerSnapshotTests.cs -->
+    <Content
+      Include="src\McpServer\**\*"
+      Exclude="
+        **\bin\**;
+        **\obj\**;
+        **\.vs\**;
+        **\*.sln;
+        **\*.in;" />
     <None Include="THIRD-PARTY-NOTICES.TXT" Pack="true" PackagePath="." />
     <Compile Remove="**\*" />
   </ItemGroup>

src/ProjectTemplates/Microsoft.Extensions.AI.Templates/src/McpServer/McpServer-CSharp/.mcp/server.json

@@ -0,0 +1,25 @@
+{
+  "description": "<your description here>",
+  "name": "io.github.<your GitHub username here>/<your repo name>",
+  "packages": [
+    {
+      "registry_name": "nuget",
+      "name": "<your package ID here>",
+      "version": "0.1.0-beta",
+      "package_arguments": [],
+      "environment_variables": [
+        {
+          "description": "The maximum number to return from the random number generator",
+          "name": "MAX_RANDOM_NUMBER"
+        }
+      ]
+    }
+  ],
+  "repository": {
+    "url": "https://github.com/<your GitHub username here>/<your repo name>",
+    "source": "github"
+  },
+  "version_detail": {
+    "version": "0.1.0-beta"
+  }
+}

src/ProjectTemplates/Microsoft.Extensions.AI.Templates/src/McpServer/McpServer-CSharp/.template.config/dotnetcli.host.json

@@ -0,0 +1,7 @@
+{
+  "$schema": "https://json.schemastore.org/dotnetcli.host",
+  "symbolInfo": {},
+  "usageExamples": [
+    ""
+  ]
+}

src/ProjectTemplates/Microsoft.Extensions.AI.Templates/src/McpServer/McpServer-CSharp/.template.config/ide.host.json

@@ -0,0 +1,6 @@
+{
+  "$schema": "https://json.schemastore.org/ide.host",
+  "order": 0,
+  "icon": "ide/icon.ico",
+  "symbolInfo": []
+}

src/ProjectTemplates/Microsoft.Extensions.AI.Templates/src/McpServer/McpServer-CSharp/.template.config/template.json

@@ -0,0 +1,46 @@
+{
+  "$schema": "http://json.schemastore.org/template",
+  "author": "Microsoft",
+  "classifications": [
+    "Common",
+    "AI",
+    "MCP"
+  ],
+  "identity": "Microsoft.Extensions.AI.Templates.McpServer.CSharp",
+  "name": "Local MCP Server Console App",
+  "description": "A project template for creating a Model Context Protocol (MCP) server using C# and the ModelContextProtocol package.",
+  "shortName": "mcpserver",
+  "defaultName": "McpServer",
+  "sourceName": "McpServer-CSharp",
+  "preferNameDirectory": true,
+  "tags": {
+    "language": "C#",
+    "type": "project"
+  },
+  "symbols": {
+    "hostIdentifier": {
+      "type": "bind",
+      "binding": "HostIdentifier"
+    }
+  },
+  "primaryOutputs": [
+    {
+      "path": "./README.md"
+    },
+    {
+      "path": "./McpServer-CSharp.csproj"
+    }
+  ],
+  "postActions": [
+    {
+      "condition": "(hostIdentifier != \"dotnetcli\" && hostIdentifier != \"dotnetcli-preview\")",
+      "description": "Opens README file in the editor",
+      "manualInstructions": [],
+      "actionId": "84C0DA21-51C8-4541-9940-6CA19AF04EE6",
+      "args": {
+        "files": "0"
+      },
+      "continueOnError": true
+    }
+  ]
+}

src/ProjectTemplates/Microsoft.Extensions.AI.Templates/src/McpServer/McpServer-CSharp/McpServer-CSharp.csproj.in

@@ -0,0 +1,32 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <OutputType>Exe</OutputType>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+
+    <!-- Set up the NuGet package to be an MCP server -->
+    <PackAsTool>true</PackAsTool>
+    <PackageType>McpServer</PackageType>
+
+    <!-- Set recommended package metadata -->
+    <PackageReadmeFile>README.md</PackageReadmeFile>
+    <PackageId>SampleMcpServer</PackageId>
+    <PackageVersion>0.1.0-beta</PackageVersion>
+    <PackageTags>AI; MCP; server; stdio</PackageTags>
+    <Description>An MCP server using the MCP C# SDK.</Description>
+  </PropertyGroup>
+
+  <!-- Include additional files for browsing the MCP server. -->
+  <ItemGroup>
+    <None Include=".mcp\server.json" Pack="true" PackagePath="/.mcp/" />
+    <None Include="README.md" Pack="true" PackagePath="/" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.Hosting" Version="${TemplatePackageVersion_MicrosoftExtensionsHosting}" />
+    <PackageReference Include="ModelContextProtocol" Version="${TemplatePackageVersion_ModelContextProtocol}" />
+  </ItemGroup>
+
+</Project>

src/ProjectTemplates/Microsoft.Extensions.AI.Templates/src/McpServer/McpServer-CSharp/Program.cs

@@ -0,0 +1,31 @@
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+using McpServer_CSharp.Tools;
+
+var builder = Host.CreateApplicationBuilder(args);
+
+// Uncomment the following lines if you want to enforce the MCP command-line arguments.
+// You can use command-line arguments to support multiple modes or commands in your application.
+// These would be specified in the "package_arguments" property in the .mcp/server.json to inform client tools.
+/*
+if (args.Length == 0 || args[0] != "mcp")
+{
+    Console.Error.WriteLine("Error: invalid command. Use the 'mcp' command-line argument to start the MCP server.");
+    return 1;
+}
+*/
+
+builder.Logging.AddConsole(consoleLogOptions =>
+{
+    // Configure all logs to go to stderr (stdout is used for the MCP protocol messages).
+    consoleLogOptions.LogToStandardErrorThreshold = LogLevel.Trace;
+});
+
+// Add the MCP services: the transport to use (stdio) and the tools to register.
+builder.Services
+    .AddMcpServer()
+    .WithStdioServerTransport()
+    .WithTools<RandomNumberTools>();
+
+await builder.Build().RunAsync();

src/ProjectTemplates/Microsoft.Extensions.AI.Templates/src/McpServer/McpServer-CSharp/README.md

@@ -0,0 +1,88 @@
+# MCP Server
+
+This README was created using the C# MCP server template project. It demonstrates how you can easily create an MCP server using C# and then package it in a NuGet package.
+
+See [aka.ms/nuget/mcp/guide](https://aka.ms/nuget/mcp/guide) for the full guide.
+
+## Checklist before publishing to NuGet.org
+
+- Test the MCP server locally using the steps below.
+- Update the package metadata in the .csproj file.
+- Update `.mcp/server.json` to declare your MCP server's inputs.
+- Pack the project using `dotnet pack`.
+
+The `bin/Release` directory will contain the package file (.nupkg), which can be [published to NuGet.org](https://learn.microsoft.com/nuget/nuget-org/publish-a-package).
+
+## Using the MCP Server in VS Code
+
+Once the MCP server package is published to NuGet.org, you can use the following VS Code user configuration to download and install the MCP server package. See [Use MCP servers in VS Code (Preview)](https://code.visualstudio.com/docs/copilot/chat/mcp-servers) for more information about using MCP servers in VS Code.
+
+```json
+{
+  "mcp": {
+    "servers": {
+      "McpServer-CSharp": {
+        "type": "stdio",
+        "command": "dotnet",
+        "args": [
+          "tool",
+          "exec",
+          "<your package ID here>",
+          "--version",
+          "<your package version here>",
+          "--yes"
+        ],
+        "env": {
+          "MAX_RANDOM_NUMBER": 100
+        }
+      }
+    }
+  }
+}
+```
+
+Now you can ask Copilot Chat for a random number, for example, `Give me 3 random numbers`. It should prompt you to use the `get_random_number` tool on the `my-custom-mcp` MCP server and show you the results.
+
+## Developing locally in VS Code
+
+To test this MCP server from source code (locally) without using a built MCP server package, create a `.vscode/mcp.json` file (a VS Code workspace settings file) in your project directory and add the following configuration:
+
+```json
+{
+  "servers": {
+    "McpServer-CSharp": {
+      "type": "stdio",
+      "command": "dotnet",
+      "args": [
+        "run"
+      ],
+      "env": {
+        "MAX_RANDOM_NUMBER": 100
+      }
+    }
+  }
+}
+```
+
+Alternatively, you can configure your VS Code user settings to use your local project:
+
+```json
+{
+  "mcp": {
+    "servers": {
+      "McpServer-CSharp": {
+        "type": "stdio",
+        "command": "dotnet",
+        "args": [
+          "run",
+          "--project",
+          "<PATH TO PROJECT DIRECTORY>"
+        ],
+        "env": {
+          "MAX_RANDOM_NUMBER": 100
+        }
+      }
+    }
+  }
+}
+```

src/ProjectTemplates/Microsoft.Extensions.AI.Templates/src/McpServer/McpServer-CSharp/Tools/RandomNumberTools.cs

@@ -0,0 +1,49 @@
+using System.ComponentModel;
+using ModelContextProtocol.Server;
+
+namespace McpServer_CSharp.Tools;
+
+/// <summary>
+/// Sample MCP tools for demonstration purposes.
+/// These tools can be invoked by MCP clients to perform various operations.
+/// </summary>
+public class RandomNumberTools
+{
+    private readonly int _maxNumber;
+
+    public RandomNumberTools()
+    {
+        // Process configuration settings from the environment variables.
+        // These will be provided by the MCP client application, such as VS Code.
+        // Configuration settings could be provided via dependency injection and the IOptions pattern.
+        var maxNumberEnv = Environment.GetEnvironmentVariable("MAX_RANDOM_NUMBER");
+        if (!int.TryParse(maxNumberEnv, out var maxNumber) || maxNumber <= 0)
+        {
+            throw new InvalidOperationException("Error: you must set the MAX_RANDOM_NUMBER environment variable to a positive integer.");
+        }
+
+        _maxNumber = maxNumber;
+    }
+
+    /// <summary>
+    /// Returns the maximum random number that can be generated by the tool.
+    /// </summary>
+    /// <returns>The maximum random number.</returns>
+    [McpServerTool(Name = "get_max_random_number")]
+    [Description("Returns the maximum random number that can be generated by the tool.")]
+    public int GetMaxRandomNumber()
+    {
+        return _maxNumber;
+    }
+
+    /// <summary>
+    /// Returns a random number between 1 and the maximum number allowed by the tool (inclusive).
+    /// </summary>
+    /// <returns>A random number.</returns>
+    [McpServerTool(Name = "get_random_number")]
+    [Description("Returns a random number between 1 and the maximum number allowed by the tool.")]
+    public int GetRandomNumber()
+    {
+        return Random.Shared.Next(1, _maxNumber + 1);
+    }
+}