C# MCP - Roslyn-Powered Code Analysis MCP Server & CLI

A dual-mode tool for C# code analysis and refactoring using Roslyn APIs. Operates as an MCP server for AI assistants or as a traditional CLI tool.

Installation

# Install as global tool (after published to NuGet)
dotnet tool install -g CSharpMcp

# Or build from source
git clone <repository-url>
cd csharp-mcp
dotnet build

MCP Server Mode (Recommended)

The solution is loaded once at startup, making subsequent tool calls fast.

csharp-mcp                                    # Auto-discover solution
csharp-mcp --solution /path/to/Solution.sln   # Explicit path

MCP Configuration

{
  "mcpServers": {
    "csharp-mcp": {
      "command": "/path/to/csharp-mcp",
      "args": ["--solution", "/path/to/your/Solution.sln"]
    }
  }
}

Available MCP Tools

Tool	Description
csharp_find_definition	Find where a symbol is defined
csharp_find_references	Find all usages of a symbol
csharp_rename	Safely rename a symbol across the solution
csharp_signature	Get method/type signatures
csharp_list_members	List members of a type
csharp_find_implementations	Find implementations of interface/abstract class
csharp_inheritance_tree	Show inheritance hierarchy
csharp_find_callers	Find methods that call a specific method
csharp_find_callees	Find methods called by a specific method
csharp_diagnostics	Get compilation errors/warnings
csharp_check_symbol_exists	Check if a symbol exists
csharp_dependencies	Analyze type dependencies
csharp_unused_code	Find potentially unused code
csharp_generate_interface	Extract interface from class
csharp_implement_interface	Generate implementation stubs
csharp_list_types	List types in namespace/file
csharp_namespace_tree	Show namespace hierarchy
csharp_analyze_file	Comprehensive file analysis

---

CLI Mode

csharp-mcp [command] [options]
csharp-mcp --solution MySolution.sln find-definition UserService --type class

Global Options

Option	Description
--solution, -s	Path to .sln file (auto-discovers if not specified)
--output, -o	Output format: json, text, markdown (default: json)
--verbose, -v	Enable verbose logging

Commands Reference

Command	Options
find-definition <symbol>	--type, -t (class/method/property/field/interface/enum), --in-file, -f, --in-namespace, -n
find-references <symbol>	--type, -t, --in-namespace, -n
rename <old> <new>	--type, -t, --in-namespace, -n, --preview, --rename-file
signature <symbol>	--type, -t, --include-overloads, --include-docs
list-members <type>	--kind, -k (method/property/field/event), --accessibility, -a, --include-inherited
find-implementations <symbol>	-
inheritance-tree <type>	--direction, -d (up/down/both)
find-callers <method>	-
find-callees <method>	-
diagnostics	--severity, -s (error/warning/info), --file, -f, --code, -c
check-symbol-exists <symbol>	--type, -t, --in-namespace, -n
dependencies <target>	-
unused-code	-
generate-interface <class>	-
implement-interface <interface>	-
list-types	--namespace
namespace-tree	-
analyze-file <path>	-

---

Requirements

• .NET 10.0 Runtime - https://dotnet.microsoft.com/download/dotnet/10.0
• Solution or project file to analyze

Technical Details

Dependencies: ModelContextProtocol (v0.7.0-preview.1), Microsoft.CodeAnalysis.CSharp.Workspaces (v5.0.0), Microsoft.Build.Locator (v1.8.1), System.CommandLine (v2.0.0-beta4)

See SPEC.md for full specification.

License

This project is licensed under the MIT License - see the LICENSE.md file for details.