jsx-dev-runtime

Runtime UI primitives for Remix apps, including the component runtime, server rendering, frame hydration, reusable mixins, and headless first-party behavior primitives.

Features

Component runtime APIs for rendering, hydration, frame navigation, and JSX
Server rendering APIs for streaming Remix UI trees and frames
mix composition with event, ref, CSS, and animation helpers
Headless behavior primitives for controls such as menus, listboxes, popovers, selects, and comboboxes
Lower-level utilities for keyboard events, typeahead search, refs, attributes, and CSS transition timing

Installation

npm i remix

Usage

Compose behavior primitives with your own markup and styles:

import { css } from 'remix/ui'
import * as popover from 'remix/ui/popover'

let triggerCss = css({
  border: '1px solid #d1d5db',
  borderRadius: '6px',
  padding: '6px 10px',
})

let surfaceCss = css({
  background: 'white',
  border: '1px solid #d1d5db',
  borderRadius: '6px',
  padding: '8px',
})

function ViewOptions() {
  let open = false

  return () => (
    <popover.Context>
      <button
        mix={[triggerCss, popover.anchor({ placement: 'bottom-end' }), popover.focusOnHide()]}
        onClick={() => {
          open = true
        }}
        type="button"
      >
        View options
      </button>
      <div
        mix={[
          surfaceCss,
          popover.surface({
            open,
            onHide() {
              open = false
            },
          }),
        ]}
      >
        Panel content
      </div>
    </popover.Context>
  )
}

Button styling is available as a composable mixin:

import button from 'remix/ui/button'

function Actions() {
  return () => <button mix={button({ tone: 'primary' })}>Create project</button>
}

Preserving Client-Owned DOM

Use rmx-preserve-dom on the smallest element whose live DOM should belong to client code after initial render, such as a custom element or third-party widget:

<pagefind-ui data-key="search" rmx-preserve-dom>
  <button type="button">Search</button>
</pagefind-ui>

Remix UI still renders the element's children during SSR and still hydrates any initial client entries inside it. On later frame reloads, matched rmx-preserve-dom elements keep their current attributes and children instead of accepting incoming DOM updates. See Preserving client-owned DOM for guidance and caveats.

Cascade Layers

Remix UI emits generated css(...) rules under the rmx cascade layer. Unlayered CSS outranks layered CSS, so use explicit layer order when mixing Remix UI with global styles.

Put layers that should lose to Remix UI before rmx:

@layer base, rmx;

@layer base {
  button,
  input,
  textarea,
  select {
    font: inherit;
    margin: 0;
    padding: 0;
  }
}

License

See LICENSE