MCP Server in C# .NET(TransportType=StdIo)

MCP是一个典型的C/S架构模式，即客户端 和 服务端，它们之间采用一种标准的消息格式（JSON-RPC）进行通信.

The MCP C# SDK has great samples of creating MCP server, MCP client

MCP Server in C# .NET

Simple MCP Server in C#

Step 1: Create a Console Application

dotnet new console -n McpServer

Step 2: Add Required Packages MCP SDK

dotnet add package ModelContextProtocol --prerelease

安装MCP SDK

 <ItemGroup>
   <PackageReference Include="ModelContextProtocol" Version="0.2.0-preview.1" />
   <PackageReference Include="Microsoft.Extensions.Hosting" Version="9.0.5" />
 </ItemGroup>

https://github.com/iaspnetcore/MCPServer/commit/fd50c9b5fd9c8d9e46b6dde9e4f99f7bac57d24f

The official C# SDK for Model Context Protocol servers and clients

ModelContextProtocol sdk

https://github.com/modelcontextprotocol/csharp-sdk

Step 3: Define Tools

创建一个Tools目录，然后添加一个TimeTool.cs

src/McpServerConsole.Server/Tools/TimeTool.cs

using ModelContextProtocol.Server;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace McpServerConsole.Server.Tools
{
    [McpServerToolType]
    public static class TimeTool
    {
        [McpServerTool, Description("Get the current time for a city")]
        public static string GetCurrentTime(string city) =>
            $"It is {DateTime.Now.Hour}:{DateTime.Now.Minute} in {city}.";
    }
}

https://github.com/iaspnetcore/MCPServer/commit/1f94a3f1c78c2aac376cff24d9317df696806eb0

step 4. Update Program.cs - Update your Program.cs to set up the MCP server

Update your Program.cs to set up the MCP server

using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using ModelContextProtocol.Server;
using System.ComponentModel;


var builder = Host.CreateApplicationBuilder(args);
builder.Logging.AddConsole(consoleLogOptions =>
{
    // Configure all logs to go to stderr
    consoleLogOptions.LogToStandardErrorThreshold = LogLevel.Trace;
});

builder.Services
    .AddMcpServer()
    .WithStdioServerTransport()
    .WithToolsFromAssembly();

await builder.Build().RunAsync();

WithToolsFromAssembly扩展方法，会自动扫描程序集中添加了McpServerTool标签的类进行注册

https://github.com/iaspnetcore/MCPServer/commit/33e996ee7c6707871ba7441d3f78cabbe2d117b4

2.MCP includes two standard transport(Built-in Transport Types) implementations

Standard Input/Output (stdio)标准IO传输方式-> .WithStdioServerTransport

Server-Sent Events (SSE) SSE传输方式        ->

step 5. run your MCP server

cd F:\developer_mcp\src\McpServerConsole.Server

McpServerConsole.Client

Step 1: Create a Console Application

Step 2: Add Required Packages

dotnet add package ModelContextProtocol" Version="0.2.0-preview.1

F:\developer_mcp

https://github.com/iaspnetcore/MCPServer.git/

blog:https://www.iaspnetcore.com/blogpost-683332645fb02c0677df0289-mcp-server-in-c-net

https://modelcontextprotocol.io/docs/concepts/transports

https://www.cnblogs.com/edisonchou/p/-/introduction-to-mcp-csharp-sdk

https://devblogs.microsoft.com/dotnet/build-a-model-context-protocol-mcp-server-in-csharp/