Grail UI

Grail UI enters the headless primitive space alongside Melt UI and Bits UI with its own take on separating behavior from presentation. The library provides a set of builder functions that return props, event handlers, and state — you spread these onto your own markup elements to get accessible interactive components without any styling opinions.

The API design draws clear inspiration from the Radix UI and Melt UI approach. You call a creation function like createAccordion(), destructure the returned helpers, and apply them to your HTML. The pattern is clean and composable, and the TypeScript support is thorough — every returned prop and handler is well-typed, making the developer experience smooth in editors with good TypeScript integration.

Where Grail UI does well is in its focus on correctness. The primitives that exist — accordion, dialog, popover, tooltip, tabs, and a handful of others — implement WAI-ARIA patterns carefully. Keyboard navigation, focus management, and screen reader support are handled properly, and the implementation details show attention to the edge cases that trip up less careful libraries.

The honest concern with Grail UI is maintenance velocity. Development has slowed considerably, with the last meaningful updates landing in late 2025. The library has around 300 GitHub stars, which reflects limited community adoption. For a headless primitive library, ongoing maintenance matters — browser behavior evolves, accessibility best practices get updated, and framework changes (particularly Svelte 5’s runes) require active adaptation.

The primitive count is also modest at roughly 20 components. Bits UI and Melt UI both offer broader coverage, which means you are more likely to need a supplemental library for less common patterns if you build on Grail UI.

That said, Grail UI remains a worthwhile reference implementation. The code is clean, the patterns are well-executed, and for smaller projects where you only need a handful of accessible primitives, it gets the job done without pulling in a larger dependency. If maintenance picks back up, it could become a more compelling option. For now, teams building production applications with strict long-term support needs should lean toward Bits UI or Melt UI instead.