Kookie UI
Kookie UI is a design-system to build consistent and scalable user interfaces.
An open-source fork of Radix Themes, focused on building scalable, consistent UI components with a fresh visual style and practical foundations.
"Components like Shell in Kookie UI are a game changer for building responsive layouts. Getting responsiveness right is so difficult otherwise — Kookie UI has significantly reduced the UI load on our team."
AnujSoftware Engineer at Womp
Writing
Announcements (4)
Building on Radix: AvatarAvatar in Kookie UI extends Radix Themes with expanded sizes, new variants, material support, status indicators, badge slots, fit control, and interactive states.
February 16, 2026Building on Radix: CardCard in Kookie UI extends Radix Themes with two new variants, a material system for translucent effects, and props for edge-to-edge content. Same foundation, more flexibility.
January 9, 2026New Component: Shell, a Layout Engine for Modern AppsShell is a declarative layout engine for application chrome. Seven layout slots, responsive presentation modes, state management, and resize with persistence—all without building layout infrastructure from scratch.
January 7, 2026New Component: Introducing Chatbar in KookieUIA composable, accessible chat input component that handles the complex parts of building AI chat interfaces while staying out of your way.
November 8, 2025Articles (4)
Kookie Blocks: Higher-Level Components for Kookie UIPre-built patterns on top of Kookie UI. Same design system, one layer higher.
February 20, 2026
Why Designers Should Own the Experience in ProductionWhy the design layer should live in code, how I do it with KookieUI for Womp, and what changes day to day.
November 12, 2025
Kookie User Interface: Building my own Design SystemKookieUI is a fork of Radix Themes with different design opinions. Same infrastructure, different choices about how a design system should work.
September 25, 2025
Who's Kookie? The Lore Behind the NameAll my projects are named after my dog Kookie. This is the lore my partner and I have created for her — the legend of Queen Lukita the Benevolent.
September 25, 2023