JFM.RoslynNavigator 0.1.1

.NET 10.0 This package targets .NET 10.0. The package is compatible with this framework or higher.
Suggested Alternatives

RoslynLens

Additional Details

This package has been renamed to RoslynLens. Install the new package with: dotnet tool install --global RoslynLens. All future updates will be published under RoslynLens.

dotnet tool install --global JFM.RoslynNavigator --version 0.1.1
This package contains a .NET tool you can call from the shell/command line. 
dotnet new tool-manifest
                    


                            if you are setting up this repo
                        

                    

                
dotnet tool install --local JFM.RoslynNavigator --version 0.1.1
This package contains a .NET tool you can call from the shell/command line. 
#tool dotnet:?package=JFM.RoslynNavigator&version=0.1.1
                    


                    

                
nuke :add-package JFM.RoslynNavigator --version 0.1.1

JFM.RoslynNavigator

A token-efficient MCP (Model Context Protocol) server for .NET codebase navigation, powered by Roslyn semantic analysis. Designed for use with Claude Code.

Instead of reading entire .cs files (500-2000+ tokens each), Claude Code queries this MCP server and receives focused, semantic results (30-150 tokens). This dramatically reduces token consumption when working with large .NET solutions.

Features

17 Navigation Tools

Tool Purpose
find_symbol Locate type/method definitions by name
find_references Find all usages of a symbol
find_implementations Find interface implementors and derived classes
find_callers Find direct callers of a method
find_overrides Find overrides of virtual/abstract methods
find_dead_code Detect unused types, methods, and properties
get_type_hierarchy Show inheritance chain, interfaces, and derived types
get_public_api Get public surface without reading the full file
get_symbol_detail Full signature, parameters, return type, and XML docs
get_project_graph Solution dependency tree
get_dependency_graph Method call chain visualization
get_diagnostics Compiler warnings and errors
get_test_coverage_map Heuristic test coverage mapping
detect_antipatterns 19 anti-pattern detectors
detect_circular_dependencies Project and type-level cycle detection
get_module_depends_on [DependsOn] attribute graph (modular monoliths)
validate_granit_conventions Convention violation checker

19 Anti-Pattern Detectors

General .NET detectors:

ID Detector Description
AP001 AsyncVoidDetector async void methods (except event handlers)
AP002 SyncOverAsyncDetector .Result, .Wait(), .GetAwaiter().GetResult()
AP003 HttpClientInstantiationDetector new HttpClient() instead of IHttpClientFactory
AP004 DateTimeDirectUseDetector DateTime.Now/UtcNow instead of TimeProvider
AP005 BroadCatchDetector catch (Exception) without re-throw
AP006 LoggingInterpolationDetector String interpolation in log calls
AP007 PragmaWithoutRestoreDetector #pragma warning disable without matching restore
AP008 MissingCancellationTokenDetector Async methods missing CancellationToken parameter
AP009 EfCoreNoTrackingDetector EF Core queries without .AsNoTracking()

Domain-specific detectors:

ID Detector Description
GR-GUID GuidNewGuidDetector Guid.NewGuid() instead of IGuidGenerator
GR-SECRET HardcodedSecretDetector Hardcoded passwords, connection strings, API keys
GR-SYNC-EF SynchronousSaveChangesDetector SaveChanges() instead of SaveChangesAsync()
GR-BADREQ TypedResultsBadRequestDetector TypedResults.BadRequest<string>() instead of Problem()
GR-REGEX NewRegexDetector new Regex() instead of [GeneratedRegex]
GR-SLEEP ThreadSleepDetector Thread.Sleep() in production code
GR-CONSOLE ConsoleWriteDetector Console.Write/WriteLine instead of ILogger
GR-CFGAWAIT MissingConfigureAwaitDetector Missing ConfigureAwait(false) in library code
GR-DTO DtoSuffixDetector Classes/records with *Dto suffix

Requirements

  • .NET 10 SDK or later
  • A .NET solution (.sln or .slnx)

Installation

dotnet tool install --global JFM.RoslynNavigator

Usage

Add to your Claude Code MCP configuration:

# User-scoped (available in all projects)
claude mcp add --scope user --transport stdio roslyn-navigator -- jfm-roslyn-navigator

# Project-scoped
claude mcp add --transport stdio roslyn-navigator -- jfm-roslyn-navigator

Or via .mcp.json in your project root:

{
  "mcpServers": {
    "roslyn-navigator": {
      "type": "stdio",
      "command": "jfm-roslyn-navigator",
      "args": []
    }
  }
}

Solution Discovery

The server automatically finds the nearest .sln or .slnx file using BFS from the current directory (max 3 levels up). You can also specify a solution explicitly:

jfm-roslyn-navigator --solution /path/to/MySolution.slnx

Standalone

jfm-roslyn-navigator

The server communicates over stdio using the MCP protocol.

Building from Source

git clone https://github.com/jfmeyers/jfm-roslyn-navigator.git
cd jfm-roslyn-navigator
dotnet build
dotnet test

Pack and install locally

dotnet pack -c Release -o ./nupkgs
dotnet tool install --global --add-source ./nupkgs JFM.RoslynNavigator

Architecture

src/JFM.RoslynNavigator/
├── Program.cs                  # Host + MCP stdio transport
├── SolutionDiscovery.cs        # BFS .sln/.slnx auto-discovery
├── WorkspaceManager.cs         # MSBuildWorkspace, LRU compilation cache
├── WorkspaceInitializer.cs     # Background solution loading
├── SymbolResolver.cs           # Cross-project symbol resolution
├── Tools/                      # 17 MCP tool implementations
├── Analyzers/                  # 19 anti-pattern detectors
└── Responses/                  # Token-optimized DTOs

Key design decisions:

  • Lazy compilation: Solutions with 50+ projects only compile on-demand (LRU cache of 50 compilations)
  • File watcher: .cs changes trigger incremental text updates; .csproj changes trigger full reload
  • Background loading: Solution loads asynchronously; tools return "loading" status until ready
  • Logs to stderr: All logging goes to stderr to keep stdout clean for JSON-RPC

Acknowledgments

Inspired by CWM.RoslynNavigator by Mukesh Murugan (MIT License). Adapted with additional detectors, auto-discovery, and global tool distribution.

License

Apache License 2.0

Product Compatible and additional computed target framework versions.
.NET net10.0 is compatible.  net10.0-android was computed.  net10.0-browser was computed.  net10.0-ios was computed.  net10.0-maccatalyst was computed.  net10.0-macos was computed.  net10.0-tvos was computed.  net10.0-windows was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.

This package has no dependencies.

Version Downloads Last Updated
0.1.1 198 3/14/2026 0.1.1 is deprecated.