McpServers

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

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

• For VS2022, 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!

Playground

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

Option 1 - NuGet Tool (.NET 10 or later)

Use the new, easier, dotnet dnx approach, as a global tool:

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

Option 2 - NPM Package

You can also use node to run the mcp server, this config uses my published npm package.

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

Option 3 - Docker Image

If you have docker installed, you can use my published docker image.

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

Tools

• GetFibonacci - Accept numerical value for maximum number of items in the sequence
• GetTribonacci - Accept numerical value for maximum number of items in the sequence
• GetTetranacci - Accept numerical value for maximum number of items in the sequence
• GetLucas - Accept numerical value for maximum number of items in the sequence

Example