Picking The Right Library

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

Motion & visuals

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

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

Interaction & performance

State & styling

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).