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Design · Any agent

Pick UI Library Agent Skill

A decision file, not an implementation file. Use it when the project has not chosen a component kit and you need an explicit pick. It should stop a silent default to shadcn. Swap to the official shadcn skill after the kit is chosen.

Compared on shadcn . How to choose a skill

SKILL.md

The file starts with a description field. Agents keep that text in context and open the rest of the file only when the job matches.

name
pick-ui-library
description
Pick the right library for a given frontend task from a curated, opinionated list — numbers, OTP inputs, charts, command menus, virtualization, drag and drop, toasts, state, styling, and more. Only runs when explicitly invoked; it does not trigger on its own.

Picking The Right Library

Initial Response

When this skill is first invoked without a specific question, respond only with:

I'm ready to pick the right library for your task, my picks come from Emil Kowalski's curated list.

Do not provide any other information until the user asks a question.

A lookup skill. When invoked with a task ("I need toasts", "what should I use for drag and drop?"), match the task to the curated list below and recommend the library. These are deliberate, taste-driven picks — don't substitute alternatives outside this list unless the user asks for one or the task genuinely isn't covered.

How to use this

  1. Identify the task, not the library the user named. "I need to show a dropdown" is a UI-primitives task (base-ui), even if they asked about something else.
  2. Check what's already installed. Look at package.json first. If the project already uses a listed library, use it. If it uses a competitor (e.g. react-window instead of Virtuoso), flag the recommendation but don't churn the dependency without being asked.
  3. Recommend one library, state what it's for in one sentence, and install/wire it up if that's part of the request. Don't present a menu of options when the list has a clear answer.
  4. If the task isn't covered by the list, say so explicitly and recommend from your own knowledge — but be clear you've left the curated list.

The list

UI components & primitives

Task Library
Unstyled, accessible UI components (dialogs, popovers, menus, selects…) base-ui
Command menus (⌘K palettes) cmdk
Toasts / notifications Sonner
One-time password / verification code inputs input-otp
Customizable GUIs / control panels Leva — dialkit is an alternative

Motion & visuals

Task Library
General-purpose animation (springs, layout animations, enter/exit) motion (Framer Motion)
Animating numbers (counters, prices, stats) NumberFlow
Animated text components torph
3D globes Cobe
Dynamic OG images (HTML/CSS → SVG/PNG) Satori
Syntax highlighting shiki

Reach for motion when you need springs, layout animations, exit animations, or gesture-driven values. A simple hover or fade doesn't need it — plain CSS transitions are the right tool there.

Charts

Task Library
Real-time / streaming charts Liveline
General charts (static or interactive dashboards) recharts

The split: if data points arrive live and the chart scrolls with time, use Liveline. Everything else is recharts.

Interaction & performance

Task Library
Drag and drop dnd kit
Virtualization (long lists, large tables) Virtuoso

State & styling

Task Library
State management zustand
Constructing className strings conditionally clsx
Type-safe, variant-driven styling for Tailwind cva
Theme switching / dark mode (no flash on load) next-themes

The styling split: clsx for ad-hoc conditional classes; cva when a component has real variants (size, intent, state) that deserve a typed API. They compose — cva uses clsx-style inputs internally.

Common mismatches to catch

  • Toasts built by hand or with a modal library → Sonner exists for exactly this.
  • A <div>-based dropdown/dialog with manual focus handling → base-ui, which handles accessibility, focus trapping, and dismissal.
  • Animating a number by re-rendering text → NumberFlow handles digit transitions properly.
  • Rendering a 1,000+ row list directly → Virtuoso before reaching for pagination hacks.
  • A useState-per-component web of props for shared state → zustand.
  • Template-literal className ternaries three conditions deep → clsx (or cva if it's variant-shaped).

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