Frontend

Expert backlog manager that prioritizes work using multi-criteria scoring, analyzes dependencies, and recommends optimal next tasks. Activates when managing backlogs, prioritizing work, adding items, or analyzing what to work on next.

Use when building C++ applications requiring modern C++20/23 features, template metaprogramming, or high-performance systems. Invoke for concepts, ranges, coroutines, SIMD optimization, memory management. Keywords: C++, C++20, C++23, templates, performance, systems programming.

Composition API vs Options API

Use when encountering unfamiliar import statements; when exploring a dependency's API; when user asks "what's import X?", "what does import X do?", or about package documentation. - Generates comprehensive API documentation for Swift package dependencies on-demand. This skill helps you quickly obtain documentation for packages used in Xcode projects when you encounter unfamiliar module imports. Automatically resolves modules to packages and caches documentation for reuse. This is the primary tool for understanding individual `import` statements.

Use this before writing any Swift code, before planning code changes and enhancements - establishes style guidelines, teaches you vital Swift techniques

Guide for creating Claude Code skills following Anthropic's official best practices. Use when user wants to create a new skill, build a skill, write SKILL.md, or needs skill creation guidelines. Provides structure, naming conventions, description writing, and quality checklist.

Provides formatting guidelines for prose. This skill's guidance is automatically applied when writing multi-line comments, commit messages, markdown, or other prose.

Frontend patterns for Next.js App Router, Clerk auth, shadcn/Radix UI, and PostHog analytics. Use when building UI components, creating pages, implementing auth flows, or adding analytics events. Ensures consistent UX patterns and accessibility standards.

Go coding standards following idiomatic Go patterns, error handling, concurrency best practices, and modern Go tooling. Use for Go projects requiring clean, efficient, production-ready code with comprehensive testing.

A service mesh is an infrastructure layer that provides transparent service-to-service communication with built-in observability, traffic management, and security features without requiring application code changes.

Create professional package release blog posts following Tidyverse or Shiny blog conventions. Use when the user needs to: (1) Write a release announcement blog post for an R or Python package for tidyverse.org or shiny.posit.co, (2) Transform NEWS/changelog content into blog format, (3) Generate acknowledgments sections with contributor lists, (4) Format posts following specific blog platform requirements. Supports both Tidyverse (hugodown) and Shiny (Quarto) blog formats with automated contributor fetching and comprehensive style guidance.

JavaScript/ES6+ coding standards following Airbnb guidelines, modern patterns, React best practices, and comprehensive Jest testing. Use for JavaScript projects requiring clean, maintainable, production-ready code with modern tooling.

This skill should be used when working with applesauce-core library for Nostr client development, including event stores, queries, observables, and client utilities. Provides comprehensive knowledge of applesauce patterns for building reactive Nostr applications.

Master Rust's ownership system, type safety, and zero-cost abstractions for building safe, concurrent, and performant systems. Covers borrowing, lifetimes, traits, error handling, async/await, and testing patterns.

TypeScript coding standards covering strict type system, advanced types, decorators, generics, and best practices for type-safe applications. Use for TypeScript projects requiring robust type safety and maintainable code.

Reference guide for code comment formatting rules and examples. The core rules are automatically applied via CLAUDE.md system instructions - this skill provides detailed examples and edge cases for reference.

Extract comprehensive design language from websites including colors, typography, animations, interactive states, shadows, gradients, component patterns, and UX behaviors. Generates pixel-perfect design guides with responsive screenshots and complete design system documentation. Use when analyzing website design, creating design systems, or rebuilding sites.

Validates test suite quality through mutation testing. Generates intelligent code mutations, runs tests to verify they catch the changes, and identifies gaps in test coverage. Use when evaluating test effectiveness, validating newly written tests, or improving test quality for mission-critical code.

React frontend standards covering hooks (useState, useEffect, useContext, custom hooks), state management (Context API, Redux, Zustand), performance optimization (memoization, lazy loading, code splitting), testing with React Testing Library, and accessibility (WCAG 2.1, ARIA) for modern SPAs

Use before implementing UI changes or frontend PRs. Enforces TodoWrite with 18+ items. Triggers: "accessibility audit", "WCAG", "Lighthouse", "screen reader", "a11y", "NVDA", "VoiceOver", "keyboard navigation", "focus indicator". For "Core Web Vitals" in frontend/UI context, use this skill. For pure backend/API performance optimization, use performance-optimization instead. If thinking "WIP doesn't need this" - use it anyway.