Create and manage Claude Code skills following Anthropic best practices. Use when creating new skills, modifying skill-rules.json, understanding trigger patterns, working with hooks, debugging skill activation, or implementing progressive disclosure. Covers skill structure, YAML frontmatter, trigger types (keywords, intent patterns, file paths, content patterns), enforcement levels (block, suggest, warn), hook mechanisms (UserPromptSubmit, PreToolUse), session tracking, and the 500-line rule.

Extract the most meaningful, engaging clips from YouTube videos. Use when user provides a YouTube URL and wants to find highlights, best moments, controversial takes, or valuable segments. Supports specifying number of clips or topic focus.

Core React 19 patterns including hooks, Suspense, lazy loading, component structure, TypeScript best practices, and performance optimization. Use when working with React components, hooks, lazy loading, Suspense boundaries, or React-specific TypeScript patterns.

Material-UI v7 component library patterns including sx prop styling, theme integration, responsive design, and MUI-specific hooks. Use when working with MUI components, styling with sx prop, theme customization, or MUI utilities.

Framework-agnostic HTTP API route testing patterns, authentication strategies, and integration testing best practices. Supports REST APIs with JWT cookie authentication and other common auth patterns.

Document learnings, capture repeatable workflows as skills, and prepare to compound an opence change.

Migrates an MCP server with interactive widgets from the OpenAI Apps SDK (window.openai, text/html+skybridge) to the MCP Apps standard (@modelcontextprotocol/ext-apps), covering server-side and client-side changes.

Event Stormingでイベント（動詞の過去形）を中心に、コマンド・集約・リードモデルを抽出/命名/レビューする作業に使う

Use for guided Fizzy.do workflows: "set up Fizzy", "configure Fizzy for this project", "sync my work to Fizzy", "review my Fizzy progress", "end of session cleanup". Provides step-by-step guidance for common operations.

Build web components using Custom Elements v1 API with Declarative Shadow DOM, attribute-driven state, handleEvent pattern, and zero DOM selection. Use when creating custom elements, extending built-in HTML elements, or implementing component-based architecture. NO querySelector, NO innerHTML, NO external libraries - pure web platform APIs only.

Design and generate Glean Agent specifications. Use when creating new agents, speccing out agent requirements, or generating JSON for Agent Builder import. Triggers on: 'create an agent', 'design an agent', 'agent spec', 'build an agent for [use case]'.

Prisma ORM patterns including Prisma Client usage, queries, mutations, relations, transactions, and schema management. Use when working with Prisma database operations or schema definitions.

Enforce code style and formatting preferences. Use when writing or reviewing code to ensure consistent style.

TanStack Router file-based routing patterns including route creation, navigation, loaders, type-safe routing, and lazy loading. Use when creating routes, implementing navigation, or working with TanStack Router.

When you need to understand the project's core mandate, operational rules, or "Constitution". Use this skill to align with the project's identity and strict coding standards.

Channel the Seven Luminors - archetypal guides for creative challenges including Valora (courage), Sophron (wisdom), Kardia (heart), Poiesis (creation), Enduran (endurance), Orakis (vision), and Eudaira (joy)

Learn how to create effective project skills following opence conventions.

Tailwind CSS v4 utility-first styling patterns

Clerk authentication integration for Astro/Next.js. Use when implementing authentication, handling Clerk middleware, testing with Playwright, or debugging auth issues. Trigger phrases include "Clerk auth", "sign in", "authentication", "middleware", "E2E testing with Clerk".

Use this skill when creating or editing issues on Github or when asked to write user-stories or record bugs.