Development

Apply 37signals/DHH Rails conventions when writing Ruby on Rails code. Use when building Rails applications, reviewing Rails code, or making architectural decisions. Covers various aspects of Rails application architecture, design and dependencies.

Interactive slash command creator for Claude Code. Triggers when user mentions creating commands, slash commands, command templates, command arguments, or wants to build a new command workflow.

Expert CSS and frontend styling specialist that analyzes codebases, maintains style guides, suggests improvements, and stays current with modern design patterns. Use when working on frontend styling, creating design systems, ensuring visual consistency, or need expert CSS/styling guidance. Integrates with oracle, summoner, and wizard.

This skill should be used when the user says "let's land the plane", "land the plane", "end the session cleanly", "wrap up the session", or asks to prepare for a clean handoff between coding sessions. Provides a systematic protocol for ensuring all work is committed, tested, tracked, and ready for the next session.

Builds and manages iOS/macOS apps using xcodebuild and xcrun simctl CLI tools. Use when working with Xcode projects, running apps in simulators, managing simulator instances, taking screenshots, capturing logs, running tests, or automating builds.

Advanced prompt engineering techniques for optimal AI responses. Use this when crafting prompts, optimizing AI interactions, or designing system prompts for applications.

Modern JavaScript and TypeScript development patterns

Git から指定範囲のコミットを収集し、Quarto（reveal.js）でスライド（HTML/PDF）を生成する。 タスクID、コミット範囲、ブランチ間の差分など、柔軟な指定方法に対応。

Guide for creating Claude Code hooks - user-defined shell commands that execute at lifecycle points. Use when the user wants to create, add, or configure a hook for Claude Code, including PreToolUse, PostToolUse, Notification, UserPromptSubmit, Stop, SubagentStop, PreCompact, SessionStart, or SessionEnd hooks.

Analyze and reduce cognitive load in code by identifying complex conditionals, deep nesting, shallow modules, excessive abstractions, and architectural over-engineering. Use when reviewing code quality, refactoring for maintainability, or simplifying systems. Keywords: cognitive load, complexity, refactor, simplify, maintainability, readability, mental overhead, abstraction, architecture review

This skill provides prescriptive guidance for writing modern CSS layouts using intrinsic design principles, container queries, and fluid responsive techniques. When implementing CSS layouts, always consult this document first.

Senior Frontend Code Reviewer with 12+ years JavaScript/TypeScript experience. Use when reviewing React/TypeScript code, checking code quality and style, verifying accessibility compliance, ensuring test coverage, or configuring linting tools (ESLint, Prettier).

TheGraph subgraph development with AssemblyScript handlers, schema definitions, and Matchstick testing. Triggers on subgraph, thegraph, graphql, mapping.ts.

Converts approved design documents into agent-executable XML subtasks. Use after a design doc is approved and ready for implementation.

Service workers, offline-first, app manifest, and native-like web experiences.

Build the Gambit game engine (Server and Client executables). Use when the user wants to compile the project, needs to rebuild after code changes, or before running the server or client.

Guide to designing and implementing tools for the vscode-copilot-chat extension, including patterns, testing, and best practices

Senior Rust engineer for systems programming. Use for ownership, async Rust, and zero-cost abstractions.

Automatically manage Python virtual environments (.venv) in terminal commands. Always activate .venv before running Python/pip commands. Use when executing Python scripts, installing packages, or running development servers. Critical for consistent environment management.

SQLAlchemy Python SQL toolkit and ORM with powerful query builder, relationship mapping, and database migrations via Alembic