SmoothUI (by Eduardo Calvo)

Use it for: AI products first — ai-approval, ai-tool-call, ai-task-list, ai-reasoning, ai-loader, ai-context-meter, ai-prompt-input are theme-token components with considered motion (the shimmer only runs while streaming, decisions collapse the alternatives, status rings draw a check). Also the gaps other free sources leave: a size-matching skeleton-loader, animated-tabs (underline/pill/segment), a shrink/hide-on-scroll floating-navbar, coverflow-carousel, card-swipe-deck, a four-variant scroll-progress, button-copy. Don't use it for: stock app primitives (its dialog, select, combobox, pagination duplicate shadcn/Origin UI) or brand-new visual identity — the creative effects (shaders, dither, ASCII) are fine but OriginKit/React Bits go further.

Install

# @smoothui is in shadcn's built-in registry directory — resolves with no components.json entry
# (the CLI adds "@smoothui": "https://smoothui.dev/r/{name}.json" itself on first install)
npx shadcn@latest add @smoothui/ai-approval @smoothui/animated-tabs

Items land in components/smoothui/<name>/index.tsx (default export), so they never clash with same-named files from other registries. Direct URLs also work: npx shadcn@latest add https://smoothui.dev/r/<name>.json.

Machine access

• https://smoothui.dev/llms-components.json — every component + block with category, tags, animationType (spring/tween/gesture/scroll/none), complexity, hasReducedMotion, dependencies, install command and docs URL. pnpm sync smoothui reads it → catalog/generated/smoothui.json (198 components + 34 blocks).
• Registry index https://smoothui.dev/r/registry.json (201 registry:ui + 35 blocks + 6 themes, tokens, lib, shared, data, a skill item); per item https://smoothui.dev/r/<name>.json. The index also has ai-core (shared AI state + motion presets), cli, the deprecated ai-input alias and a chat-template block — not in llms-components.json, so not catalogued.
• pnpm scan-motion --only smoothui reads every item's source for code-level motion signals.
• llms.txt with one line per item; docs at https://smoothui.dev/docs/components/<name> (blocks: one page per group, e.g. /docs/blocks/cta).

Gotchas

• tokens.json and --brand. 66 items pull https://smoothui.dev/r/tokens.json (a registry:theme), which adds --color-brand (defaults to pink, oklch(0.72 0.2 352.53)), a smooth-50…1000 grey ramp and blue/green/amber button families. 48 items use bg-brand/text-brand/border-brand (tab underlines, focus rings, stat values, scroll-progress). Add --brand: var(--primary); to :root in globals.css once and they follow the theme.

• Custom smooth-N palette: 5 items style with the smooth-* ramp instead of shadcn tokens — header-1, inline-testimonials, job-listing-component, pixel-flow-field, smooth-button (and anything that installs smooth-button, e.g. coverflow-carousel's prev/next buttons). Neutral greys, so mostly harmless; check them under coloured themes.

• Hard-coded hex: 25 items contain hex colours (not counting #fff/#000); 10 have three or more — liquid-metal (38), theme-toggle (15), pixel-brush-canvas (10), ransom-note, wallet-card (7), grid-loader, job-listing-component (5), header-1 (4), mac-terminal, unlock-face-id (3). basic-toast, dynamic-island, stats-2 and pricing-1 use raw Tailwind palette classes (bg-emerald-50, bg-black…) instead. AI status accents (ai-tool-call, ai-task-list, ai-context-meter) are fixed oklch green/amber/red.

• Reduced motion: the hasReducedMotion flag is accurate when true (132 items) but under-reports — the code handles it in ~213 of 232 items (e.g. coverflow-carousel, dock, border-beam are flagged false but use useReducedMotion). The catalog takes both: the flag (as a reduced-motion tag) and the scan. skeleton-loader really doesn't (Tailwind animate-pulse) — add motion-reduce:animate-none.

• Relative imports: AI items import ../ai-core; keep components/smoothui/* together. apple-invites lists @smoothui/data as an npm dependency, but no such npm package exists (404) — it's the registry data item; expect the npm step to fail and add it with npx shadcn@latest add @smoothui/data.

• floating-navbar is absolute-positioned (pass className="fixed"); several blocks import @/components/smoothui/shared (auto-installed).

• Name collisions (29) with other sources — ids stay unique (smoothui/…), but pick deliberately:

  name	also in	prefer
  dock	magicui, motion-primitives, cult-ui, react-bits	magicui / motion-primitives (navigation playbook)
  border-beam	magicui, librariesdev	oc/beam-card (librariesdev, theme-tinted)
  progressive-blur	magicui, motion-primitives	motion-primitives
  scroll-progress	magicui, motion-primitives	smoothui for ring/number/segmented variants; magicui for a plain bar
  code-block	kibo-ui, cult-ui, aceternity, beautifui	kibo-ui (shiki, theme-aware)
  animated-tabs	cult-ui	smoothui (keyboard, three variants)
  floating-navbar	aceternity	smoothui (theme tokens, reduced motion)
  animated-list	magicui, react-bits	magicui
  infinite-slider, text-morph, dialog	motion-primitives	motion-primitives (dialog: stock shadcn first)
  dynamic-island	cult-ui, aceternity	cult-ui (SmoothUI's hard-codes black/white)
  file-tree, tweet-card	magicui	magicui
  combobox, contribution-graph	kibo-ui	kibo-ui
  magnetic-button, animated-tooltip	aceternity	smoothui for theme tokens; aceternity for its look
  animated-input, dither-image, morph-surface	cult-ui	compare live
  orb	react-bits	compare live
  liquid-metal, cursor-image-trail	originkit (metered)	smoothui is free — compare live
  notification-badge	transitions (recipe)	transitions for a CSS-only badge
  context-menu, cursor-follow, scroll-image-reveal, tilt-card	motion (examples)	different things — Motion's are recipes

Best picks

See ★ entries: grep '★ .*smoothui/' catalog/CATALOG.md. Short list: ai-approval, ai-tool-call, ai-task-list, ai-reasoning, ai-loader, ai-prompt-input, ai-context-meter, skeleton-loader, animated-tabs, floating-navbar, coverflow-carousel, card-swipe-deck, scroll-progress, button-copy.