ILSpy MCP Server

A Model Context Protocol (MCP) server that provides .NET assembly decompilation and analysis capabilities.

🎯 What is this?

ILSpy MCP Server enables AI assistants (like Claude Desktop, Cursor) to decompile and analyze .NET assemblies directly through natural language commands. It integrates ILSpy to provide powerful reverse-engineering capabilities.

🚀 Quick Start

Prerequisites

• .NET 8.0 or higher
• ILSpy installed or ILSpy CLI available
• MCP-compatible client (Cursor, Claude Desktop, etc.)

Installation

1. Clone the repository:

   git clone https://github.com/bivex/ILSpy-Mcp.git
   cd ILSpy-Mcp
   

2. Build the project:

   dotnet build -c Release
   

3. Configure MCP Client:

   For Claude Desktop, add to claude_desktop_config.json:

   {
     "mcpServers": {
       "ilspy-mcp": {
         "command": "dotnet",
         "args": ["/path/to/ILSpy-Mcp.dll"]
       }
     }
   }
   

   For Cursor, configure in MCP settings:

   {
     "servers": {
       "ilspy-mcp": {
         "command": "dotnet",
         "args": ["/path/to/ILSpy-Mcp.dll"]
       }
     }
   }
   

Usage Examples

Decompile an Assembly

Decompile the assembly /path/to/MyAssembly.dll and show me the Main method

List All Types

List all types in the assembly /path/to/MyLibrary.dll

Find a Specific Method

Find the CalculateTotal method in the assembly /path/to/Calculator.dll

Analyze Type Hierarchy

Show me the type hierarchy for ProductService in /path/to/ECommerce.dll

Search Members

Search for members containing "Authenticate" in /path/to/Auth.dll

Architecture

This server follows a clean architecture with clear separation of concerns:

• Domain: Core business logic and entities
• Application: Use cases and application services
• Infrastructure: External system adapters (ILSpy, file system)
• Transport: MCP protocol layer

Capabilities

• Decompile types, methods, and assemblies
• List and search types in assemblies
• Analyze assembly structure and architecture
• Find type hierarchies and relationships
• Discover extension methods
• Search members by name

Configuration

Configuration is managed through environment variables and appsettings.json.

Security

• All operations are read-only (no file modifications)
• Assembly path validation
• Timeout and cancellation support
• Request context propagation

Requirements

• .NET 8.0+
• ILSpy or ILSpy CLI
• MCP-compatible client

License

See LICENSE file for details.