Building agents with Google ADK requires knowing dozens of API patterns. This skill provides a curated reference for agent definitions, tools, callbacks, multi-agent orchestration, and graph workflows so you write correct code on the first try.

Frontend pull requests often contain bugs, accessibility issues, and style violations that slip past manual review. This skill provides a structured workflow for Claude to systematically review frontend code changes before they are merged.

This is a deliberately broken skill fixture designed to test packager error handling. It is not intended for production use but serves as a validation case for development tooling.

Setting up Python environments with specialized libraries takes time and effort. This skill runs Python code in a remote sandbox with 100+ libraries pre-installed, accessible via a simple CLI command.

Creating multi-component React artifacts for Claude conversations requires complex bundling and configuration. This skill automates project setup with React 18, TypeScript, Tailwind CSS, and 40+ shadcn/ui components, then bundles everything into a single HTML file.

Building performant React applications requires understanding complex optimization patterns. This skill provides 45 prioritized rules from Vercel Engineering to guide AI in writing, reviewing, and refactoring React and Next.js code for optimal performance.

Writing tests after code leads to false confidence and missed edge cases. This skill enforces the TDD discipline: write a failing test first, then implement just enough code to pass.

Developers often miss issues in their own code because they are too close to the implementation. This skill dispatches an AI subagent to review code changes against requirements, checking quality, architecture, testing, and production readiness before merging.

This skill automates adding multi-language support to Next.js websites, including hreflang tags, locale configuration, translation files, and SEO optimization for international markets.

Coding agents often produce work that cannot be checked. This skill turns vague agent requests into a bounded loop contract with snapshot JSON, observable verifiers, stop rules, and explicit human gates.

Stop reinventing the wheel when debugging. This skill recalls historical fixes and root causes from your ChatCrystal memory, helping you diagnose failing tests, compiler errors, and runtime exceptions faster by leveraging past debugging sessions.

Creating effective MCP servers requires understanding protocol specifications, SDK patterns, and testing strategies. This skill provides comprehensive guides for building high-quality MCP servers in Python and TypeScript with evaluation frameworks to validate tool effectiveness.

Code duplication leads to maintenance nightmares and inconsistent behavior. This skill guides you through a systematic 4-step process to identify, abstract, replace, and verify refactoring changes that eliminate repetition and improve code quality.

Lint failures slow down code reviews and block releases. This skill runs the project lint workflow and guides fixes while keeping code behavior unchanged.

Browser extension projects often struggle with cross-browser compatibility and proper internationalization setup. This skill provides clear guidance for WXT-based extension development supporting Chrome, Firefox, and Edge with proper i18n structure.

Building browser userscripts requires understanding metadata blocks, GM APIs, and runtime-specific differences between Tampermonkey and ScriptCat. This skill provides structured guidance for creating, debugging, and publishing userscripts with proper permissions and best practices.

Code reviews catch bugs before deployment but are time-consuming. This skill provides structured checklists, security patterns, and best practices for MERN stack reviews to ensure nothing critical is missed.

Writing backend tests takes significant time and requires knowledge of test frameworks. This skill analyzes your code structure, detects your testing setup, and generates comprehensive tests covering happy paths, error cases, and edge cases.

Debugging complex Next.js applications requires inspecting routes, components, and build configurations. This skill provides MCP-based tools to list routes, examine components, and check build info directly from your development environment.

Creating MCP servers for external services requires understanding protocol specifications, tool design patterns, and evaluation methodologies. This guide provides comprehensive instructions for building production-quality MCP servers in Python and TypeScript with best practices for tool design, authentication, error handling, and testing.