Meta has released Astryx, an open source design system that is fully customizable and built to be operated by both people and the AI agents working alongside them. It is available now in Beta. Astryx is not a new experiment. It grew inside Meta over the last eight years, where the company says it became its most-used and largest design system, shaped by the engineers, designers, and product teams who depend on it daily.
The system ships 150+ accessible components (the docs site now lists 160+), brand-level theming, dark mode, ready-to-ship templates, and a CLI as one cohesive package. It is built on React and StyleX. You import pre-built CSS and use typed React components. There is no build plugin to wire up and no styling library to adopt.
The trade-off Astryx is trying to remove
Most design systems force a choice. Adopt a large company’s system and your app tends to look like someone else’s product. Reach for copy-paste components instead and every project forks its own snippets, with no shared coherence, no upstream fixes, and accessibility quietly becoming your problem.
Astryx separates the two concerns. The system controls behavior, accessibility, and quality. Themes control how it looks. You customize at the token level (color, type, radius, motion) so the app becomes unmistakably yours without rewrites. A theme is simply a set of CSS custom property overrides, so a designer can retheme Astryx without forking or wrapping component source.
