MCP (Model Context Protocol)

The MCP infrastructure provides a framework for exposing application functionality as tools that can be invoked by AI assistants like Claude.

Overview

MCP is a protocol that allows AI assistants to interact with external tools and services. This framework implements:

• Tool Registration — Discover and register tools from assemblies
• Tool Execution — Route tool calls through a message bus with timeout handling
• Transport Layer — Support for stdio (CLI) and HTTP transports
• Tool Management — Enable/disable tools at runtime with optional persistence

Quick Start

1. Add MCP Services

// In your service configuration
builder.Services.AddMcp(options =>
{
    options.ServerName = "MyApp";
    options.ServerVersion = "1.0.0";
});

// Register tools from your assembly
builder.Services.AddMcpTools();

2. Initialize MCP

// After building services
app.Services.UseMcp();

3. Create a Tool

[McpTool(Name = "greet", Description = "Greets a user by name")]
public class GreetTool : IMcpTool<GreetInput>
{
    public Task<McpToolResult> ExecuteAsync(GreetInput input, CancellationToken cancellationToken = default)
    {
        return Task.FromResult(McpToolResult.Text($"Hello, {input.Name}!"));
    }
}

public class GreetInput
{
    [McpToolInput(Description = "The name to greet", Required = true)]
    public string Name { get; set; } = "";
}

Architecture

┌─────────────────┐     ┌──────────────┐     ┌─────────────────┐
│   MCP Client    │────▶│  Transport   │────▶│   McpServer     │
│ (Claude, etc.)  │◀────│ (stdio/HTTP) │◀────│                 │
└─────────────────┘     └──────────────┘     └────────┬────────┘
                                                      │
                                                      ▼
                                             ┌─────────────────┐
                                             │   MessageBus    │
                                             └────────┬────────┘
                                                      │
                                                      ▼
                                             ┌─────────────────┐
                                             │ McpToolRegistry │
                                             │ + ToolHandler   │
                                             └────────┬────────┘
                                                      │
                                                      ▼
                                             ┌─────────────────┐
                                             │    IMcpTool     │
                                             │ Implementation  │
                                             └─────────────────┘

Components

Component	Description
McpServer	Handles JSON-RPC protocol messages
McpServerState	Manages server lifecycle and tool state
McpToolRegistry	Stores and manages tool descriptors
McpToolLoader	Discovers tools from assemblies via reflection
McpToolCallHandler	Executes tool calls through the message bus
IMcpTransport	Abstraction for message transport

Topics

• Tools — Creating and registering tools
• Transports — stdio vs HTTP transport