Design Atlas
Type
component registry
Verdict
Very useful
Licence
Ship licence, open source permissiveopen-source-permissivefree and open source under MIT (repo educlopez/smoothui); funded by sponsors, no paid tier found
Agent channels
llms-txt, cli, registry, api
Pricing
free
Reviewed

← Atlas · Topics: components, motion, ai-interfaces, agents-and-prompts

Smooth UI ​

Type
component registry
Verdict
Very useful
Licence
Ship licence, open source permissiveopen-source-permissivefree and open source under MIT (repo educlopez/smoothui); funded by sponsors, no paid tier found
Agent channels
llms-txt, cli, registry, api
Pricing
free
Reviewed

What it is ​

SmoothUI is a library of animated React components by Eduardo Calvo, made for React 19, Tailwind CSS v4 and shadcn/ui, with motion from Motion and, according to the site, GSAP. Its llms.txt counted 198 components and 34 page blocks at the time of review, and the site also has templates and a playground. The repo is very active (commits the day before this review) and is in Vercel's 2026 OSS programme.

When to open it ​

When you are building an AI product interface and want its moving parts to feel deliberate: streaming responses, reasoning traces, tool calls, citations, task plans. Also a good source of everyday animated controls (tabs, toggles, OTP inputs, steppers, toasts).

Most useful ​

  • A large AI set (20 items): prompt input, streaming response, reasoning trace, tool-call status, sources stack, context meter, diff view, approval card and a generative agent avatar
  • Everyday controls with motion built in: animated tabs, number input with scrubbing, OTP input, stepper, tooltip, toast
  • Showpiece effects such as a Siri-style orb, a Dynamic Island, an aperture shader transition and an ASCII renderer
  • Page blocks for heroes, pricing, FAQ, features, logo clouds, stats, team, testimonials and footers

Using it with agents ​

Unusually complete for agents. /llms.txt lists every component with category, complexity and install command; /llms-full.txt and /llms-components.json give full and structured versions. A public REST API (no auth, OpenAPI spec at /openapi.json) supports listing, search, suggestions and source retrieval. Components install with npx shadcn@latest add @smoothui/<name> or the project's own npx smoothui-cli add <name>, and the shadcn MCP server works with the @smoothui namespace.

Watch out for ​

  • Descriptions vary in quality: many entries say little more than "a … component for SmoothUI", so preview before choosing
  • Components expect Tailwind v4 and React 19; older stacks may need manual adjustment
  • The site cross-promotes the maker's separate agent tool (UI Craft, installed via Homebrew), which is not part of the library

Reusable ideas ​

  • Tag each component with a complexity level so agents and humans can judge the cost of adopting it
  • Expose a no-auth search and source API next to llms.txt for retrieval pipelines
  • Design AI states around one visual element that evolves (a ring that spins, then draws a check) instead of swapping icons

Prompt Kit, The Shape of AI, Magic UI, shadcn/ui, Kokonut UI, Animate UI