Remote MCP Server Using .NET SDK: Prompts

This repository contains a sample remote Model Context Protocol (MCP) server built with the .NET SDK and ModelContextProtocol.AspNetCore.

The server exposes:

• MCP tools (for operations such as ping and weather lookup)
• MCP prompts (for reusable instruction templates)
• HTTP MCP endpoint at /mcp
• Health endpoint at /api/healthz

What This Project Is

The project is an ASP.NET Core MCP server that can be used by MCP clients (including VS Code MCP client configuration in .vscode/mcp.json).

Source layout:

• src/McpServer/McpServer: MCP host application
• src/McpServer/WeatherService: weather service used by the weather tool
• scripts: PowerShell scripts to list and call MCP tools/resources/prompts

Prerequisites

• Windows with PowerShell (pwsh or Windows PowerShell)
• .NET SDK 10.0 (project targets net10.0)
• VS Code with MCP client support
• Internet access for weather lookup (uses Open-Meteo APIs)

Run The Server Locally

From the repository root:

dotnet restore .\src\McpServer\McpServer.slnx
dotnet run --project .\src\McpServer\McpServer\McpServer.csproj

Default server URL:

• http://0.0.0.0:8081/mcp

Notes:

• Port is controlled by FUNCTIONS_CUSTOMHANDLER_PORT (defaults to 8081).
• Health check endpoint: http://localhost:8081/api/healthz

VS Code MCP Client Configuration

This repository already includes .vscode/mcp.json:

{
  "servers": {
    "local-mcp-server": {
      "url": "http://0.0.0.0:8081/mcp",
      "type": "http"
    }
  }
}

If needed, update url to match your local port.

Exposed MCP Tools

Defined in src/McpServer/McpServer/McpServerTools.cs:

• Ping(message: string)
  • Verifies server responsiveness and optionally echoes a message.
• GetWeather(city: string)
  • Returns current weather data for the requested city.

Tool names shown by MCP clients can be normalized by the MCP library. Use tools/list (or the script below) to confirm exact callable names in your environment.

Exposed MCP Prompts

Defined in src/McpServer/McpServer/McpServerPrompts.cs and registered in src/McpServer/McpServer/Program.cs with:

.WithPrompts<McpServerPrompts>();

Available prompts:

• default_prompt

  • Description: Default system prompt for the MCP server.
  • Returns a concise system instruction set:
    • be concise
    • prefer plain text
    • do not hallucinate
    • ask for clarification when input is unclear

• weather_query_guide(userContext?: string)

  • Description: Guidance on how to ask for weather forecasts in a structured way.
  • Optional argument:
    • userContext: extra location or preference context appended to the prompt output.

• weather_data_interpretation

  • Description: Instructions for interpreting weather forecast data returned by the server.
  • Includes formatting guidance for temperature, summary, context, and recommendations.

Use prompts/list to see exact prompt names and argument metadata in your runtime.

How To Create A New MCP Prompt

Use this pattern from McpServerPrompts when adding a new prompt.

1. Add or reuse a prompt container class and mark it with [McpServerPromptType].
2. Add a public method and mark it with [McpServerPrompt].
3. Add a [Description("...")] attribute so clients can show meaningful metadata.
4. For input arguments, add [Description("...")] attributes for better client introspection.
5. Return string or Task<string>.
6. Ensure the prompt type is registered in startup (already done with .WithPrompts<McpServerPrompts>()).
7. Run the server and validate with prompts/list and prompts/get.

Example (new prompt in McpServerPrompts.cs):

[McpServerPrompt]
[Description("Provides concise guidance for travel weather planning")]
public Task<string> TravelWeatherGuide(
    [Description("Destination city")] string city,
    [Description("Optional number of travel days")] int? days = nul

... [View full README on GitHub](https://github.com/azurecorner/remote-MCP-servers-using-dotnet-sdk-prompts#readme)