Create a project template for an MCP server

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

@@ -46,7 +46,7 @@
   <ItemGroup>
     <!-- Keep the exclude patterns below in sync with those in AIChatWebSnapshotTests.cs -->
     <Content
-      Include="src\*\**\*"
+      Include="src\ChatWithCustomData\**\*"
       Exclude="
         **\bin\**;
         **\obj\**;
@@ -61,6 +61,14 @@
         **\NuGet.config;
         **\Directory.Build.targets;
         **\Directory.Build.props;" />
+    <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

@@ -6,17 +6,7 @@
       "registry_name": "nuget",
       "name": "<your package ID here>",
       "version": "0.1.0-beta",
-      "package_arguments": [
-        {
-          "description": "Start the MCP server tool in server mode",
-          "is_required": true,
-          "format": "string",
-          "value": "start-mcp",
-          "default": "start-mcp",
-          "type": "positional",
-          "value_hint": "start-mcp"
-        }
-      ],
+      "package_arguments": [],
       "environment_variables": [
         {
           "description": "The maximum number to return from the random number generator",
@@ -32,4 +22,4 @@
   "version_detail": {
     "version": "0.1.0-beta"
   }
-}
+}

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

@@ -1,10 +1,14 @@
 {
   "$schema": "http://json.schemastore.org/template",
   "author": "Microsoft",
-  "classifications": [ "Common", "AI", "MCP" ],
+  "classifications": [
+    "Common",
+    "AI",
+    "MCP"
+  ],
   "identity": "Microsoft.Extensions.AI.Templates.McpServer.CSharp",
   "name": "Local MCP Server Console App",
-  "description": "A project template for creating a local MCP server using the .NET MCP SDK.",
+  "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",
@@ -13,9 +17,30 @@
     "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

@@ -5,7 +5,7 @@
     <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>
@@ -17,11 +17,10 @@
     <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=".mcp\server.json" Pack="true" PackagePath="/.mcp/" />
     <None Include="README.md" Pack="true" PackagePath="/" />
   </ItemGroup>
 
@@ -30,4 +29,4 @@
     <PackageReference Include="ModelContextProtocol" Version="${TemplatePackageVersion_ModelContextProtocol}" />
   </ItemGroup>
 
-</Project>
+</Project>

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

@@ -1,59 +1,32 @@
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Logging;
-using ModelContextProtocol.Server;
-using System.ComponentModel;
+using McpServer_CSharp.Tools;
 
 var builder = Host.CreateApplicationBuilder(args);
 
-if (args.Length == 0 || args[0] != "start-mcp")
+// 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 'start-mcp' command-line argument to start the MCP server.");
-    return 1;
-}
-
-var maxNumberEnv = Environment.GetEnvironmentVariable("MAX_RANDOM_NUMBER");
-if (!int.TryParse(maxNumberEnv, out var maxNumber) || maxNumber <= 0)
-{
-    Console.Error.WriteLine("Error: you must set the MAX_RANDOM_NUMBER environment variable to a positive integer.");
+    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, discover tools from the current assembly
+// Add the MCP services: the transport to use (stdio) and the tools to register.
 builder.Services
     .AddMcpServer()
     .WithStdioServerTransport()
-    .WithTools<RandomNumberTool>();
-
-// add dependencies for the MCP server tools
-builder.Services.AddSingleton(_ => new RandomNumberService(maxNumber));
+    .WithTools<RandomNumberTools>();
 
 await builder.Build().RunAsync();
 return 0;
-
-public class RandomNumberService(int max)
-{
-    public int Max => max;
-    public int GetRandomNumber() => Random.Shared.Next(1, max + 1);
-}
-
-public class RandomNumberTool(RandomNumberService service)
-{
-    [McpServerTool, Description("Returns the maximum random number that can be generated by the tool.")]
-    public int MaxRandomNumber()
-    {
-        return service.Max;
-    }
-
-    [McpServerTool, Description("Returns a random number between 1 and the maximum number allowed by the tool.")]
-    public int GetRandomNumber()
-    {
-        return service.GetRandomNumber();
-    }
-}

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

@@ -1,14 +1,17 @@
 # MCP Server
 
-This README was created using the .NET MCP server template project. It demonstrates how you can easily create an MCP server using .NET and then package it in a NuGet package.
+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
 
-- Update the package metadata in the .csproj file
-- Update `.mcp/server.json` to declare your MCP server's inputs
-- Test the MCP server locally using the steps below
+- 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
 
@@ -18,7 +21,7 @@ Once the MCP server package is published to NuGet.org, you can use the following
 {
   "mcp": {
     "servers": {
-      "my-custom-mcp": {
+      "McpServer-CSharp": {
         "type": "stdio",
         "command": "dotnet",
         "args": [
@@ -27,9 +30,7 @@ Once the MCP server package is published to NuGet.org, you can use the following
           "<your package ID here>",
           "--version",
           "<your package version here>",
-          "--yes",
-          "--",
-          "start-mcp"
+          "--yes"
         ],
         "env": {
           "MAX_RANDOM_NUMBER": 100
@@ -40,25 +41,42 @@ Once the MCP server package is published to NuGet.org, you can use the following
 }
 ```
 
-Now you can ask Copilot Chat for a random number, for example, `Give me 3 random numbers`. It should prompt you to use the `GetRandomNumber` tool on the `my-custom-mcp` MCP server and show you the results.
+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:
 
-## Developing locally
+```json
+{
+  "servers": {
+    "McpServer-CSharp": {
+      "type": "stdio",
+      "command": "dotnet",
+      "args": [
+        "run"
+      ],
+      "env": {
+        "MAX_RANDOM_NUMBER": 100
+      }
+    }
+  }
+}
+```
 
-To test this MCP server from source code (locally) without using a built MCP server package, use the following VS Code configuration:
+Alternatively, you can configure your VS Code user settings to use your local project:
 
 ```json
 {
   "mcp": {
     "servers": {
-      "my-custom-mcp": {
+      "McpServer-CSharp": {
         "type": "stdio",
         "command": "dotnet",
         "args": [
           "run",
           "--project",
-          "<PATH TO PROJECT DIRECTORY>",
-          "--",
-          "start-mcp"
+          "<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);
+    }
+}