Xstate

Build React chat interfaces with Vercel AI SDK v6. Covers useChat/useCompletion/useObject hooks, message parts structure, tool approval workflows, and 18 UI error solutions. Prevents documented issues with React Strict Mode, concurrent requests, stale closures, and tool approval edge cases. Use when: implementing AI chat UIs, migrating v5→v6, troubleshooting "useChat failed to parse stream", "stale body values", "React maximum update depth", "Cannot read properties of undefined (reading 'state')", or tool approval workflow errors.

Apply when building, customizing, or deploying extensions for VTEX Sales App. Covers the complete 7-step workflow from prerequisite checks through code generation to deployment, including extension points (cart, PDP, menu), React hooks (useCart, usePDP, useCartItem, useCurrentUser, useExtension), TypeScript types, secure API integration patterns, and API documentation ingestion (OpenAPI, URLs, or inline specs) to generate typed integrations.

Build or modify plain HTML/CSS/JavaScript (no framework) using modular ES modules (ESM), SRP, minimal global state, and shippable runnable files with lightweight verification. Use for static pages, small UI widgets, vanilla JS refactors, and quick prototypes without React/Vue/Angular.

Design and implement web animations that feel natural and purposeful. Use this skill proactively whenever the user asks questions about animations, motion, easing, timing, duration, springs, transitions, or animation performance. This includes questions about how to animate specific UI elements, which easing to use, animation best practices, or accessibility considerations for motion. Triggers on: easing, ease-out, ease-in, ease-in-out, cubic-bezier, bounce, spring physics, keyframes, transform, opacity, fade, slide, scale, hover effects, microinteractions, Framer Motion, React Spring, GSAP, CSS transitions, entrance/exit animations, page transitions, stagger, will-change, GPU acceleration, prefers-reduced-motion, modal/dropdown/tooltip/popover/drawer animations, gesture animations, drag interactions, button press feel, feels janky, make it smooth.

When the user wants to create, optimize, or audit a comparison table section—an in-page block (HTML table or responsive equivalent) comparing products, methods, or approaches, with optional supporting copy. Also use when the user mentions "comparison table," "compare table," "feature matrix," "vs table," "side-by-side comparison," "competitor comparison," "traditional vs modern," "manual vs automated," "before and after," "old way vs new way," "alternatives comparison block," or "comparison section on landing page or blog." This skill is for a section inside a page, not a full alternatives URL or blog post wireframe—use alternatives-page-generator for page-level layout, keywords, and PPC destination strategy. For full-page structured data rules, use schema-markup. For FAQ blocks paired with the table, use faq-page-generator.

Extract color palettes from images, websites, or designs. Identifies dominant colors, generates complementary schemes, and exports in multiple formats (HEX, RGB, HSL, Tailwind, CSS variables). Use when users need color schemes from images, brand colors, or design system palettes.