MCP Server Template

A comprehensive .NET template for creating Model Context Protocol (MCP) servers using ASP.NET Core. This template provides a robust foundation for building MCP servers that can integrate with AI assistants and other MCP clients.

What is MCP?

The Model Context Protocol (MCP) is an open standard for enabling AI assistants to securely access external resources and tools. MCP servers provide three main capabilities:

• Tools: Functions that can be called by AI assistants to perform actions
• Resources: Read-only data that assistants can access for context
• Prompts: Reusable prompt templates for common AI tasks

Quick Start

Using the Template

1. Install the template:

   dotnet new install ./
   

2. Create a new MCP server:

   dotnet new mcp-server -n MyCompany.McpServer
   cd MyCompany.McpServer
   

3. Run the server:

   dotnet run
   

The server will start on http://localhost:5000 by default.

Template Parameters

• --ServerName: Display name for your MCP server (default: "My MCP Server")
• --Port: Port number for the server (default: 5000)
• --Framework: Target framework (default: net8.0)

Example:

dotnet new mcp-server -n Acme.WeatherServer --ServerName "Acme Weather Service" --Port 8080

Project Structure

├── .template.config/           # Template configuration
│   └── template.json
├── Extensions/                 # Utility extensions
│   └── HttpClientExtensions.cs
├── Tools/                      # MCP tools implementation
│   └── ExampleTools.cs
├── Prompts/                    # MCP prompts implementation
│   └── ExamplePrompts.cs
├── Resources/                  # MCP resources implementation
│   └── ExampleResources.cs
├── Program.cs                  # Application entry point
├── appsettings.json           # Configuration
├── Dockerfile                 # Docker configuration
└── README.md                  # This file

Creating Custom Tools

Tools are functions that AI assistants can call to perform actions. Here's how to create them:

1. Create a Tool Class

using System.ComponentModel;
using ModelContextProtocol.Server;

namespace YourNamespace.Tools;

[McpServerToolType]
public class MyTools
{
    [McpServerTool, Description("Performs a custom operation")]
    public static string MyTool([Description("Input parameter")] string input)
    {
        // Your tool logic here
        return $"Processed: {input}";
    }
}

2. Async Tools with Dependencies

[McpServerTool, Description("Fetches data from an API")]
public static async Task<string> FetchData(
    HttpClient httpClient,  // Injected dependency
    [Description("API endpoint")] string endpoint)
{
    var response = await httpClient.GetStringAsync(endpoint);
    return response;
}

3. Complex Return Types

[McpServerTool, Description("Gets user information")]
public static string GetUserInfo([Description("User ID")] int userId)
{
    var user = new { Id = userId, Name = "John Doe", Email = "john@example.com" };
    return JsonSerializer.Serialize(user, new JsonSerializerOptions { WriteIndented = true });
}

Creating Custom Prompts

Prompts are reusable templates for AI interactions:

using Microsoft.Extensions.AI;
using ModelContextProtocol.Server;

namespace YourNamespace.Prompts;

[McpServerPromptType]
public class MyPrompts
{
    [McpServerPrompt, Description("Creates a prompt for data analysis")]
    public static ChatMessage AnalyzeData(
        [Description("Data to analyze")] string data,
        [Description("Analysis type")] string analysisType = "summary")
    {
        return new ChatMessage(ChatRole.User,
            $"Please perform a {analysisType} analysis of this data: {data}");
    }
}

Creating Custom Resources

Resources provide read-only access to data:

using ModelContextProtocol.Protoco

... [View full README on GitHub](https://github.com/TheEagleByte/csharp-mcp-server-template#readme)