Lancelot.Playground.MCP 2026.321.8

McpServers

A collection of experimental MCP servers and tools that use .NET for the backend. It shows you how to write an mcp server using .NET, but also how to publish an MCP server as a .NET SDK Tool (NuGet package), an npm package or a docker image.

Workflow	Status
main
publish (NuGet)
publish (npm)
publish (docker)

Tools

This package currently exposes 3 tools:

• GetFibonacci

  • Input: length (string, optional, default: "20")
  • Behavior: Generates Fibonacci numbers up to the numeric limit.

• GetLucas

  • Input: length (string, optional, default: "20")
  • Behavior: Generates Lucas numbers up to the numeric limit.

• GetLatLongInfo

  • Input: coordinates (string, required, format: "lat,long")
  • Behavior: Returns current date/time and location/timezone info for the coordinates.

Installation

To add an mcp server to GitHub Copilot chat, open the appropriate file:

• For Visual Studio, use %UserProfile%/.mcp.json
• For VSCode, use %appdata%/Code/User/mcp.json

Once open, update it with one of the config options. If you want to speed testing up, you can use one option for VS2022 and the other for VSCode!

Option 1 - NuGet Tool

Add the MCP server to your mcp config with the following entry

{
  "servers": {
    "mcp-playground": {
      "type": "stdio",
      "command": "dnx",
      "args": ["Lancelot.Playground.MCP", "--yes"]
    },
  }
}

Option 2 - NPM Package

Add the MCP server to your mcp config with the following entry

{
  "servers": {
    "mcp-playground": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@lancemccarthy/mcp-playground@latest"]
    }
  }
}

Option 3 - Docker Image

If you have docker installed, you can add the MCP server to your mcp config with the following entry

{
  "servers": {
    "mcp-playground": {
      "type": "stdio",
      "command": "docker",
      "args": ["run", "-i", "--rm", "docker.io/lancemccarthy/mcp-playground:latest"]
    }
  }
}