Base UI (@base-ui/react) ported to the octane UI framework — headless, accessible, unstyled UI primitives.

npm install @octanejs/base-ui
pnpm add @octanejs/base-ui

This binding targets Base UI 1.8.0. The complete export surface is implemented, including Select, Combobox, Autocomplete, Drawer, Navigation Menu, OTP Field, Scroll Area, and Toolbar. It peers on Octane ^0.2.5; see MIGRATION.md for added, replaced, and removed surfaces. Pristine and native unit, browser, type, and hydration checks pass; see UPSTREAM.md for the pinned source and evidence.

Use it in an Octane application with the Octane compiler enabled. ES module exports ship authored source so the application compiler selects client or server output. Compile these source entries with the consuming application’s Octane toolchain.

Mirrors Base UI's deep-subpath imports:

import { Separator } from '@octanejs/base-ui/separator';
import { useRender } from '@octanejs/base-ui/use-render';
import { mergeProps } from '@octanejs/base-ui/merge-props';
import { Select } from '@octanejs/base-ui/select';
import { Combobox } from '@octanejs/base-ui/combobox';

Rendered component parts support Base UI's composition props — render (a JSX element or (props, state) => element), className (string or (state) => string), and style (object or (state) => object) — routed through useRenderElement. CSS text strings are not accepted by Base UI's style composition API.

The optional temporal adapters require their matching peer packages:

npm install date-fns @date-fns/tz # Date-fns adapter
npm install luxon               # Luxon adapter

TypeScript users of the Luxon adapter also need @types/luxon.

From the repository root:

pnpm --dir packages/base-ui test          # Native, differential and SSR tests
pnpm --dir packages/base-ui test:upstream # Adapted upstream suite in jsdom
pnpm --dir packages/base-ui test:browser  # Adapted upstream suite in Chromium
pnpm --dir packages/base-ui test:pristine # Immutable React oracle in jsdom
pnpm --dir packages/base-ui upstream:verify

Upgrade octane to 0.2.5 or later in the 0.2 line together with this binding, @octanejs/base-ui-utils, @octanejs/testing-library, and @octanejs/shadcn when used. These packages require the compiler, hydration, and act support released in that coordinated patch. Earlier Octane 0.1 and 0.2 releases are not supported.

• Select, Combobox, Autocomplete, Drawer, Navigation Menu, OTP Field, Scroll Area, Toolbar, temporal adapters, and the remaining upstream parts are now available.
• Existing primitives use the Base UI 1.8 implementations and public props. Keep using component namespaces such as Accordion.Root and Dialog.createHandle. Previously exported named components, handle constructors/factories, Toast manager helpers, and Tabs type aliases remain available at the root and their component entries. useMediaQuery(query) still works from the root or /unstable-use-media-query; its options remain optional.
• Packages publish authored Octane source. Use the Octane compiler integration in your consumer toolchain; precompiled CommonJS export conditions are no longer provided.
• The export map now lists the upstream public entries explicitly. The previous /internal and wildcard /utils/* implementation paths are unavailable. Import supported utilities from @octanejs/base-ui-utils, for example @octanejs/base-ui-utils/usePreviousValue, and composite primitives from @octanejs/base-ui/internals/composite. Other private implementation paths have no supported replacement contract.

• Native events, not synthetic. Handlers receive native DOM events (octane delegates natively). event.preventBaseUIHandler() still works — the shim is attached to the native event.
• ref-as-prop. No forwardRef; ref is a normal prop (React-19 shape).
• className composition follows octane's normalizeClass at the apply site; the render-prop merge concatenates strings exactly like Base UI.
• Octane does not replay mount effects in Strict Mode or implement React's Server Components Flight format.

Current scope, known divergences, and verification status are tracked in the generated bindings status table, sourced from this package's status.json.