csharp-marketplace

C# Marketplace Plugin

![Version]() ![.NET]() ![C#]() ![Claude Code]()

한국어

A Claude Code plugin for C# and WPF development. Provides code review/refactoring/MVVM generation skills focused on Modern C# 12/13, OOP principles, SOLID principles, and GoF design patterns.

Key Features

Skills

| Skill | Description | |-------|-------------| | csharp-code-review | OOP/SOLID/GoF + Performance/Security/Async code review | | csharp-refactor | Apply SOLID principles, introduce design patterns, convert to Modern C# syntax | | wpf-mvvm-generator | Generate ViewModel/View/Model based on CommunityToolkit.Mvvm | | csharp-best-practices | C# 12/.NET 8 coding guidelines knowledge-base (12 rules, 3-tier architecture inspired by vercel-react-best-practices) | | csharp-tdd-develop | TDD-based C# development (Red-Green-Refactor workflow) | | csharp-test-develop | Write test code for existing C# classes | | project-setup | Initialize C#/.NET project for Claude Code (CLAUDE.md + context hooks for Bash/PowerShell) — based on agents.md outperforms skills |

MCP Servers

| Server | Description | |--------|-------------| | Context7 | .NET, WPF, NuGet official documentation search |

Supported Features

Modern C# Features (C# 12/13)

• Primary constructors
• Collection expressions [1, 2, 3]
• required / init properties
• Pattern matching
• Record types
• params collections (C# 13)
• System.Threading.Lock (C# 13)

CommunityToolkit.Mvvm

• [ObservableProperty] Source Generator
• [RelayCommand] / [AsyncRelayCommand]
• WeakReferenceMessenger Pub/Sub
• Dependency Injection Integration

Code Review Checklist

• OOP four pillars
• SOLID principles
• GoF design pattern opportunities
• Modern C# feature utilization
• Performance (memory allocation, Span<T>, Memory<T>, LOH)
• Async/Await patterns
• Security (SQL Injection, XSS, etc.)

Installation

Method 1: Install via npx (Recommended)

# Install all skills (global — enables `npx skills update`)
npx skills add JeongHeonK/c-sharp-custom-marketplace -g

# Install specific skills only (global)
npx skills add JeongHeonK/c-sharp-custom-marketplace --skill csharp-code-review -g
npx skills add JeongHeonK/c-sharp-custom-marketplace --skill csharp-refactor wpf-mvvm-generator -g

# Install to project scope (does NOT support `npx skills update`)
npx skills add JeongHeonK/c-sharp-custom-marketplace

> Note: npx skills update only tracks globally installed skills (-g flag). Project-scoped skills must be updated by re-running npx skills add.

Method 2: Install via Claude Code UI

1. Type /plugin to open the plugin manager 2. Press Tab to navigate to the Marketplaces tab 3. Select Add Marketplace and press Enter 4. Enter the path: JeongHeonK/c-sharp-custom-marketplace 5. Select desired skills from the Discover tab to install

Installation Scope

When installing via the /plugin UI, you can choose the scope:

• User scope: Available across all projects (default)
• Project scope: Available to all collaborators in the repository
• Local scope: Available only to you in the repository

Plugin Structure

c-sharp-marketplace/
├── .claude-plugin/
│   ├── plugin.json          # Plugin metadata
│   └── marketplace.json     # Marketplace manifest
├── skills/
│   ├── csharp-best-practices/
│   │   ├── SKILL.md         # Best practices guideline skill
│   │   └── rules/           # 12 guideline rule files
│   ├── csharp-code-review/
│   │   └── SKILL.md         # Code review skill
│   ├── csharp-refactor/
│   │   └── SKILL.md         # Refactoring skill
│   ├── csharp-tdd-develop/
│   │   ├── SKILL.md         # TDD workflow orchestrator
│   │   └── scripts/
│   │       └── test-detector.js  # .csproj test env detection
│   ├── csharp-test-develop/
│   │   ├── SKILL.md         # Test code writing skill
│   │   └── references/
│   │       └── csharp-test-patterns.md  # C# test patterns guide
│   ├── project-setup/
│   │   ├── SKILL.md         # Project initialization skill
│   │   ├── scripts/
│   │   │   ├── setup.sh     # Hook setup (Bash)
│   │   │   └── setup.ps1    # Hook setup (PowerShell)
│   │   ├── references/
│   │   │   └── claude-md-template.md  # CLAUDE.md generation template
│   │   └── assets/hooks/    # Hook scripts (.sh + .ps1)
│   └── wpf-mvvm-generator/
│       └── SKILL.md         # MVVM generation skill
├── .mcp.json                # MCP server configuration
├── CLAUDE.md                # Project conventions
└── README.md

> Note: After installing the plugin, the skills/ directory is automatically recognized, enabling slash commands (/skill-name). (Claude Code 2.1.3+)

Usage

Skills

Code Review

/csharp-code-review
/csharp-code-review src/Services/UserService.cs

Code Refactoring

/csharp-refactor                                    # Full analysis
/csharp-refactor src/Services/UserService.cs        # Specific file
/csharp-refactor src/Services/UserService.cs solid  # SOLID refactoring only
/csharp-refactor src/Services/UserService.cs modern # Modern C# syntax conversion

Best Practices Guidelines

/csharp-best-practices                      # Show all rules
/csharp-best-practices primary-constructor  # Specific topic
/csharp-best-practices record              # Record types guide

TDD Development

/csharp-tdd-develop UserService            # TDD workflow for UserService
/csharp-tdd-develop 주문 처리 서비스        # TDD workflow for order service

Test Code Writing

/csharp-test-develop src/Services/UserService.cs  # Write tests for file
/csharp-test-develop OrderService                  # Find and write tests for class

MVVM Code Generation

/wpf-mvvm-generator User                    # Generate full MVVM for User
/wpf-mvvm-generator Product viewmodel       # Generate ProductViewModel only
/wpf-mvvm-generator Order view              # Generate OrderView only

Project Setup

/project-setup                              # Initialize current project
/project-setup init /path/to/project        # Initialize specific project
/project-setup migrate                      # Add sections to existing CLAUDE.md
/project-setup hooks                        # Install hook scripts only

MCP Server (Context7)

Add "use context7" to your prompt for documentation search:

"Show me how to use IAsyncEnumerable in C# use context7"
"CommunityToolkit.Mvvm ObservableProperty examples use context7"
".NET 8 Span<T> best practices use context7"

Code Principles

OOP Four Pillars

• Encapsulation
• Inheritance
• Polymorphism
• Abstraction

SOLID Principles

| Principle | Description | |-----------|-------------| | SRP | Single Responsibility Principle | | OCP | Open/Closed Principle | | LSP | Liskov Substitution Principle | | ISP | Interface Segregation Principle | | DIP | Dependency Inversion Principle |

GoF Design Patterns

Creational Patterns: Singleton, Factory Method, Abstract Factory, Builder, Prototype

Structural Patterns: Adapter, Bridge, Composite, Decorator, Facade, Flyweight, Proxy

Behavioral Patterns: Chain of Responsibility, Command, Iterator, Mediator, Memento, Observer, State, Strategy, Template Method, Visitor

Naming Conventions

| Type | Convention | Example | |------|------------|---------| | Classes, Methods, Properties | PascalCase | UserService, GetById | | Local variables, Parameters | camelCase | userId, isActive | | Private fields | _camelCase | _repository, _logger | | Interfaces | I prefix | IRepository, IUserService | | Async methods | Async suffix | GetByIdAsync |

Recommended Project Structure

/src
  /Models          - Domain models
  /ViewModels      - MVVM ViewModels (partial classes)
  /Views           - WPF XAML Views
  /Services        - Business services
  /Repositories    - Data access layer
  /Messages        - Messenger message types
  /Converters      - IValueConverter implementations
  /Infrastructure  - Common infrastructure
/tests
  /UnitTests       - Unit tests
  /IntegrationTests - Integration tests

Requirements

• Claude Code CLI 2.1.3+ (required, supports symlinked skills)
• Node.js 18+ (for Context7 MCP server)
• .NET 8/9 SDK
• Visual Studio 2022 / JetBrains Rider

Changelog

v1.8.0 (2026-02-10)

Remove Custom Agents — npx skills Compatibility

Removed agents/ directory and switched to general-purpose sub-agent delegation for full npx skills add compatibility. Agent expertise is now provided via inline prompt context and existing rules/references.

| Change | Description | |--------|-------------| | agents/ (Removed) | Removed csharp-expert.md, wpf-expert.md, AGENTS.md | | csharp-tdd-develop (Updated) | Switched to general-purpose sub-agent; added C# expert context to Task prompts | | csharp-test-develop (Updated) | Same changes as csharp-tdd-develop | | CLAUDE.md (Updated) | 3-tier → 2-tier architecture documentation |

---

v1.7.0 (2026-02-06)

Skills Localization & Quality Improvements

Converted all user-facing skill outputs to Korean and improved skill quality based on systematic audit.

| Change | Description | |--------|-------------| | csharp-code-review (Updated) | SKILL.md body localized to Korean; output format template fully translated; technical term consistency enforced | | csharp-refactor (Updated) | SKILL.md body localized to Korean; added C# version annotations to Modern syntax table; added TargetFramework detection; added error handling section | | wpf-mvvm-generator (Updated) | SKILL.md body localized to Korean; clarified all option generates 6 component types; added entity name validation; added error handling section; improved project structure scanning with Glob patterns |

---

v1.6.1 (2026-02-03)

Inline Docs Index Pattern — Passive Context for CLAUDE.md

Applied a 2-tier "inline docs index" pattern to the CLAUDE.md template generated by project-setup. Key patterns from C# best practices, test patterns, and WPF/MVVM are now inlined as compact summaries in ## C#/.NET Quick Reference, enabling agents to leverage them as passive context every turn without explicit file reads. Detailed reference files are preserved in ## Detailed References for edge cases.

| Change | Description | |--------|-------------| | claude-md-template.md (Updated) | Added ## C#/.NET Quick Reference (~140 lines of compact inline summaries); renamed file-path tables to ## Detailed References; added conditional sections for WPF, Test, and TargetFramework | | project-setup/SKILL.md (Updated) | Extended Step 4 conditional section handling (4 conditions); added Quick Reference verification to Step 6 checklist; updated migrate subcommand | | CLAUDE.md (Updated) | Updated Development Guidelines with Quick Reference + Detailed References maintenance instructions |

---

v1.5.0 (2025-01-30)

Plugin Modularization

Added new skills for best practices, TDD development, and test code writing. The csharp-best-practices skill follows the 3-tier architecture (SKILL.md + AGENTS.md + rules/) inspired by vercel-react-best-practices.

| Change | Description | |--------|-------------| | csharp-best-practices (New) | C# 12/.NET 8 coding guidelines knowledge-base with 12 rule files (modeled after vercel-react-best-practices) | | csharp-tdd-develop (New) | TDD Red-Green-Refactor workflow orchestrator | | csharp-test-develop (New) | Test code writing skill for existing code (xUnit/Moq/FluentAssertions) | | csharp-code-review (Updated) | Removed "Positive Aspects" section — issues only output |

---

v1.4.0 (2025-01-27)

Claude Code 2.1.x Compatibility Improvements

Updated documentation and structure in accordance with the integration of skills and slash commands in Claude Code 2.1.3+.

| Change | Description | Related Version | |--------|-------------|-----------------| | Skill slash commands | Direct invocation via /csharp-code-review, etc. | v2.1.3 | | user-invocable setting | Slash command menu visibility configuration | v2.1.3 | | Documentation improvements | Clarified plugin structure and usage | - |

---

v1.3.0 (2025-01-24)

Claude Code 2.1.x Compatibility Update

This update reflects major changes from the Claude Code 2.0.x ~ 2.1.x release notes.

Skill Updates

| Item | Description | Related Version | |------|-------------|-----------------| | context: fork | Execute in forked sub-agent context | v2.1.0 | | argument-hint | Slash command argument hint display | v2.1.0 | | user-invocable | Slash command menu visibility | v2.1.3 | | skills field | Auto-load skills for sub-agents | v2.1.0 | | $ARGUMENTS[0] | New argument access syntax (replaces $ARGUMENTS.0) | v2.1.19 |

New Skills

• csharp-refactor: Apply SOLID principles, introduce design patterns, convert to Modern C# syntax
• wpf-mvvm-generator: Generate ViewModel/View/Model code based on CommunityToolkit.Mvvm

Other

• Added LSP tool support (go-to-definition, find-references, hover) - v2.0.74
• New Task Management System support - v2.1.16

---

v1.2.0

• Added marketplace.json for Marketplace distribution
• Improved plugin installation guide

v1.1.0

• Added Modern C# 12/13 feature support
• Added CommunityToolkit.Mvvm Source Generators guide
• Added Performance Review section (Span<T>, Memory<T>, LOH)
• Added Async Code Review checklist
• Added Security Review section

v1.0.0

• Initial release
• Code Review skill
• Context7 MCP server configuration

License

MIT