Use when feature flag tests fail, flags need updating, understanding @gate pragmas, debugging channel-specific test failures, or adding new flags to React.

Use when adding new error messages to React, or seeing "unknown error code" warnings.

Use when you want to validate changes before committing, or when you need to check all React contribution requirements.

Comprehensive React and Vite SPA performance, architecture, and deployment guidelines. Use this skill when building, reviewing, or refactoring React applications built with Vite (SPA). Covers...

Use when you need to check feature flag states, compare channels, or debug why a feature behaves differently across release channels.

Use when you need to run Flow type checking, or when seeing Flow type errors in React code.

Deep architectural planning with --ultrathink (32K tokens) followed by phased creation with fresh context. Two-stage workflow - UltraPlan creates comprehensive PHASES.md, then Create builds each...

Evaluate product desirability, market positioning, and emotional resonance—the complement to friction analysis. Assess whether users will WANT a product (not just use it), identity fit, trust...

React-specific component, hook, and rendering patterns. Extends platform-frontend with React rules. Use when writing React components or hooks.

TanStack Router patterns for type-safe routing. Extends platform-frontend with router-specific rules. Use when building with TanStack Router.

Generate realistic mock API responses with fake data. Use for testing, prototyping, or creating sample data for frontend development.

Next.js 15 App Router patterns - use for frontend pages, API routes, server components, client components, and middleware

TanStack Form patterns for type-safe form management. Extends platform-frontend with form-specific rules. Use when building forms with TanStack Form.

WCAG and ARIA best practices for web UIs. Extends platform-frontend with accessibility-specific rules. Use when building any user-facing interface.

JavaScript and TypeScript development with ES6+, Node.js, React, and modern web frameworks. Use for frontend, backend, or full-stack JavaScript/TypeScript projects.

JavaScript and TypeScript development with ES6+, Node.js, React, and modern web frameworks. Use for frontend, backend, or full-stack JavaScript/TypeScript projects.

JavaScript and TypeScript development with ES6+, Node.js, React, and modern web frameworks. Use for frontend, backend, or full-stack JavaScript/TypeScript projects.

Vite next-gen frontend tooling: dev server, HMR, build, config, plugins, Environment API, Rolldown. Keywords: vite.config, bundler.

Toolkit for interacting with and testing local web applications using Playwright. Supports verifying frontend functionality, debugging UI behavior, capturing browser screenshots, and viewing browser logs.

Toolkit for interacting with and testing local web applications using Playwright. Supports verifying frontend functionality, debugging UI behavior, capturing browser screenshots, and viewing browser logs.