TimHeuer.SampleDotnetMcpServer

SampleDotnetMcpServer

This project is a sample implementation of a Model Context Protocol (MCP) server in .NET, designed to demonstrate how to build, run, and publish an MCP server using C# and the ModelContextProtocol SDK.

mcp-name: io.github.timheuer/sampledotnetmcpserver

What is this?

SampleDotnetMcpServer is a reference MCP server for .NET, showing how to:

• Implement MCP tools in C# (see Tools/RandomNumberTools.cs)
• Register tools and configure the MCP server transport (see Program.cs)
• Package and publish the server as a NuGet package for use in IDEs like VS Code and Visual Studio

The included tool, get_random_number, generates random numbers and can be invoked by MCP clients (such as Copilot Chat) for demonstration purposes.

Features

• Implements the MCP protocol using stdio transport
• Provides a sample tool: get_random_number (returns a random integer in a range)
• Ready to be packed and published as a NuGet MCP server
• Example configuration files and metadata included

How to use

Run locally

You can run the MCP server directly from source for development and testing:

dotnet run --project .

Or configure your IDE to use the following MCP server definition:

{
  "servers": {
    "SampleDotnetMcpServer": {
      "type": "stdio",
      "command": "dotnet",
      "args": [
        "run",
        "--project",
        "<PATH TO PROJECT DIRECTORY>"
      ]
    }
  }
}

Test the MCP server

Once running, you can use Copilot Chat or any MCP client to invoke the get_random_number tool. For example, ask: "Give me 3 random numbers" and select the tool from the SampleDotnetMcpServer MCP server.

Publish to NuGet.org

New recommended flow:

1. Set the version number as an environment variable:

$env:MCP_VERSION = "0.1.0-beta"

1. Generate the server.json file:

pwsh .mcp/generate-server-json.ps1 -Template .mcp/server.template.json -Output .mcp/server.json

1. Pack the NuGet package:

dotnet pack -c Release

1. Publish:

dotnet nuget push bin/Release/*.nupkg --api-key <your-api-key> --source https://api.nuget.org/v3/index.json

CI Integration (GitHub Actions)

The provided workflow automatically:

1. Installs nbgv (Nerdbank.GitVersioning CLI)
2. Extracts the NuGetPackageVersion and exports it as MCP_VERSION
3. Generates .mcp/server.json from the template
4. Packs, signs, and publishes the package, then later publishes to the MCP registry.

Core excerpt:

      - name: Install Nerdbank.GitVersioning CLI
        run: dotnet tool install --global nbgv
      - name: Compute version (Nerdbank.GitVersioning)
        id: nbgv
        shell: pwsh
        run: |
          $json = nbgv get-version -f json | ConvertFrom-Json
          $nugetVersion = $json.NuGetPackageVersion
          echo "MCP_VERSION=$nugetVersion" >> $env:GITHUB_ENV
      - name: Generate server.json
        shell: pwsh
        run: pwsh .mcp/generate-server-json.ps1 -Template .mcp/server.template.json -Output .mcp/server.json -Version $env:MCP_VERSION

Use from NuGet.org

After publishing, configure your IDE to use the MCP server from NuGet.org. Example configuration:

{
  "servers": {
    "SampleDotnetMcpServer": {
      "type": "stdio",
      "command": "dnx",
      "args": [
        "TimHeuer.SampleMcpServer",
        "--version",
        "0.1.0-beta",
        "--yes"
      ]
    }
  }
}

Project structure

• Program.cs: MCP server entry point and configuration
• Tools/RandomNumberTools.cs: Example MCP tool implementation
• .mcp/server.json: MCP server metadata and NuGet package info
• SampleDotnetMcpServer.csproj: Project and NuGet packaging configuration

Learn more

• ModelContextProtocol SDK
• Model Context Protocol Documentation
• Protocol Specification
• GitHub Organization
• Use MCP servers in VS Code (Preview)
• Use MCP servers in Visual Studio (Preview)

This project is for demonstration and reference purposes only. For feedback or contributions, see the GitHub repository.