Kobra vs Origin UI

If you search for Origin UI today, originui.com sends you to coss.com/ui. Origin UI was an open source collection of 600+ copy-and-paste React and Tailwind components, built on Radix and React Aria. Cal.com acquired it, and it is now coss ui: the official Cal.com design system, rebuilt on Base UI from the ground up. The original collection is still online at coss.com/origin, and its examples are being reworked into what coss ui calls particles.

That makes this a closer comparison than most. coss ui and Kobra sit on the same stack: Base UI underneath, Tailwind v4, React 19, installed through the shadcn CLI. coss ui is free and MIT licensed, with 50+ primitives and 529 particles. Kobra is 100+ components sold once for $199, with 11 free.

This guide compares Kobra with coss ui, since that's where Origin UI lives now, and notes where the legacy collection still differs.

How Kobra and Origin UI compare

What each one is

The two catalogs are shaped differently. coss ui keeps its primitives small (button, field, select, dialog and the rest) and puts the variety into particles, which are ready-made compositions of those primitives: many ways to lay out an input with a label and a hint, or a button with an icon and a count. Kobra puts the variety inside each component instead. A Kobra toast, table or dropzone is one thing with a lot of behavior, rather than many arrangements of a simpler one.

How you install it

Both are shadcn registries, so both drop into an existing components.json and neither installs a runtime package you have to keep updated.

Who keeps it going

Where Kobra goes deeper

Behavior inside each component

A toast that stacks and reads swipe velocity. An OTP input that animates a paste across its slots. A magnetic dropzone that leans toward the file you're carrying. Filter chips that join into one track as neighbors are chosen. A button that turns its label out and a spinner in while it waits on the server. These states are the product, and they're the part a set of particles, however large, leaves you to build.

Components coss ui doesn't cover

A CRM table and a grouped table where coss ui has a plain one, a color picker and a logo picker, an image gallery with a lightbox, a QR code, a video player and a chart. On the agent side, chat history, a trace waterfall, reasoning steps, an agent map and image generation, for teams building AI products. coss ui's catalog is aimed at what Cal.com needs, which is forms, fields, overlays and dates, and it covers those well: a number field, a meter, a segmented control and a toolbar are all there. Kobra's reaches further into data, media and agent interfaces.

A Figma kit

Kobra publishes 52 primitives in Figma on the same tokens as the code, free on the Figma Community. coss ui's documentation doesn't mention a Figma file. If someone on your team designs before you build, that's a step Kobra covers.

Motion and sound as a system

Every Kobra component has a reduced-motion path, motion tuned for actions people repeat all day, and an optional sound layer where every control answers a press with a cue. Agent skills for motion and sound explain the rules so a coding agent extends them rather than breaking them.

Right to left, written in

Kobra writes every component by reading direction, including arrow keys, swipes and sliders, and keeps Arabic and Persian words joined through its text animations. Add ?dir=rtl to any component page to see it mirrored.

Where Origin UI goes deeper

It's free, and MIT

coss ui costs nothing and its source is public under MIT, with the original Origin UI copyright carried in the license. For a team that can't spend on components, that ends the comparison.

Sheer number of ready-made patterns

529 particles today, on the way to matching the 600+ examples the old Origin UI collection had. If what you want is to browse twenty versions of an input or a pagination bar and copy the one that fits, coss ui has far more of them than Kobra.

Proven in a large product

coss ui is the design system Cal.com is adopting for its own scheduling product. Components that carry a real scheduling application get exercised in ways a library's own previews never will.

A path off Radix

coss ui publishes a migration guide for teams moving from Radix or shadcn/ui to Base UI, and the legacy Origin UI collection is still there for anyone who isn't ready to move. Kobra has a design-system migration skill for agents, but no equivalent of a whole Radix-based collection to fall back on.

Theme as one install

@coss/style installs the whole theme in one step, and the color tokens can be installed on their own. Kobra's tokens arrive with each component rather than as a separate theme package.

What they cost

The question isn't whether $199 is less than free. It's whether the components you need already exist in coss ui. If they do, use them. If you'd otherwise spend a week building a data table or an agent interface on top of coss ui's primitives, the license is the cheaper path.

Kobra's prices read from the vendor's own pricing page on 30 October 2026. coss ui charges nothing and has no pricing page.

Should you use both?

They mix more easily than most pairs on this site. Both are Base UI, both are Tailwind v4, both install through the shadcn CLI, so there's no second headless library and no conflicting runtime. The sensible split is coss ui's primitives and particles for forms and everyday controls, and Kobra for the components coss ui doesn't have.

The one thing to settle up front is tokens. Each library brings its own theme variables, so pick one set and map the other onto it, or the two halves will drift apart in color and radius. And where both ship a component with the same name, such as Button or Dialog, keep one.

When to choose Kobra or Origin UI

Origin UI grew into something more serious than a copy-paste collection, and coss ui is a strong free foundation on exactly the stack Kobra uses. Kobra is what you add when the components you need are the ones a free library hasn't built yet.