ilspy-mcp-server

# ILSpy MCP Server A Model Context Protocol (MCP) server that provides .NET assembly decompilation capabilities using ILSpy. ## Features - **Decompile Assemblies**: Convert .NET assemblies back to readable C# source code - **List Types**: Enumerate classes, interfaces, structs, delegates, and enums in assemblies - **Generate Diagrammer**: Create interactive HTML visualizations of assembly structure - **Assembly Information**: Get metadata about .NET assemblies ## Prerequisites 1. **ILSpy Command Line Tool**: Install the global dotnet tool: ```bash dotnet tool install --global ilspycmd ``` 2. **Python 3.8+**: Required for running the MCP server ## Installation Install from PyPI: ```bash pip install ilspy-mcp-server ``` Or for development: ```bash git clone https://github.com/Borealin/ilspy-mcp-server.git cd ilspy-mcp-server pip install -e . ``` ## Usage ### MCP Client Configuration Configure your MCP client (e.g., Claude Desktop) to use the server: ```json { "mcpServers": { "ilspy": { "command": "python", "args": ["-m", "ilspy_mcp_server.server"] } } } ``` ### Available Tools #### 1. `decompile_assembly` Decompile a .NET assembly to C# source code. **Parameters:** - `assembly_path` (required): Path to the .NET assembly file - `output_dir` (optional): Output directory for decompiled files - `type_name` (optional): Specific type to decompile - `language_version` (optional): C# language version (default: "Latest") - `create_project` (optional): Create a compilable project structure - `show_il_code` (optional): Show IL code instead of C# - `remove_dead_code` (optional): Remove dead code during decompilation - `nested_directories` (optional): Use nested directories for namespaces **Example:** ```json { "name": "decompile_assembly", "arguments": { "assembly_path": "/path/to/MyAssembly.dll", "type_name": "MyNamespace.MyClass", "language_version": "CSharp10_0" } } ``` #### 2. `list_types` List types in a .NET assembly. **Parameters:** - `assembly_path` (required): Path to the .NET assembly file - `entity_types` (optional): Array of entity types to list ("c", "i", "s", "d", "e") **Example:** ```json { "name": "list_types", "arguments": { "assembly_path": "/path/to/MyAssembly.dll", "entity_types": ["c", "i"] } } ``` #### 3. `generate_diagrammer` Generate an interactive HTML diagrammer. **Parameters:** - `assembly_path` (required): Path to the .NET assembly file - `output_dir` (optional): Output directory for the diagrammer - `include_pattern` (optional): Regex pattern for types to include - `exclude_pattern` (optional): Regex pattern for types to exclude #### 4. `get_assembly_info` Get basic information about an assembly. **Parameters:** - `assembly_path` (required): Path to the .NET assembly file ### Available Prompts #### 1. `analyze_assembly` Analyze a .NET assembly and provide insights about its structure. #### 2. `decompile_and_explain` Decompile a specific type and provide explanation of its functionality. ## Supported Assembly Types - .NET Framework assemblies (.dll, .exe) - .NET Core/.NET 5+ assemblies - Portable Executable (PE) files with .NET metadata ## Supported C# Language Versions - CSharp1 through CSharp12_0 - Preview - Latest (default) ## Quick Start 1. **Install the package**: ```bash pip install ilspy-mcp-server ``` 2. **Configure your MCP client** (Claude Desktop example): ```json { "mcpServers": { "ilspy": { "command": "python", "args": ["-m", "ilspy_mcp_server.server"] } } } ``` 3. **Use the tools** in your MCP client: - Ask to decompile a .NET assembly - List types in an assembly - Generate interactive diagrams - Get assembly information ## Error Handling The server provides detailed error messages for common issues: - Assembly file not found - Invalid assembly format - ILSpyCmd not installed or not in PATH - Permission issues - Decompilation failures ## Configuration ### Environment Variables - `LOGLEVEL`: Set logging level (DEBUG, INFO, WARNING, ERROR). Default: INFO ### MCP Client Examples **Claude Desktop** (`config.json`): ```json { "mcpServers": { "ilspy": { "command": "python", "args": ["-m", "ilspy_mcp_server.server"], "env": { "LOGLEVEL": "INFO" } } } } ``` **Development/Testing**: ```json { "mcpServers": { "ilspy": { "command": "python", "args": ["-m", "ilspy_mcp_server.server"], "env": { "LOGLEVEL": "DEBUG" } } } } ``` ## Troubleshooting ### Common Issues 1. **"ILSpyCmd not found"**: ```bash dotnet tool install --global ilspycmd ``` 2. **"Assembly file not found"**: - Check the file path is correct - Ensure the file has .dll or .exe extension 3. **Permission errors**: - Ensure read access to assembly files - Check output directory permissions ### Debug Mode Enable debug logging to see detailed operation info: ```json { "env": { "LOGLEVEL": "DEBUG" } } ``` ## License This project is licensed under the MIT License - see the LICENSE file for details. ## Acknowledgments - Built on top of the excellent [ILSpy](https://github.com/icsharpcode/ILSpy) decompiler - Uses the [Model Context Protocol](https://modelcontextprotocol.io/) for integration