Monochrome

Accessible UI component library. Best-in-class performance. HTML-first, React and Vue supported.

Install

npm install monochrome

import "monochrome"                               // Core (auto-activates)
import { Accordion } from "monochrome/react"       // React
import { Accordion } from "monochrome/vue"         // Vue

Usage

import "monochrome"
import { Accordion } from "monochrome/react"

export function FAQ() {
  return (
    <Accordion.Root type="single">
      <Accordion.Item>
        <Accordion.Header>
          <Accordion.Trigger>What is monochrome?</Accordion.Trigger>
        </Accordion.Header>
        <Accordion.Panel>
          <p>A tiny, accessible UI component library.</p>
        </Accordion.Panel>
      </Accordion.Item>
    </Accordion.Root>
  )
}

Import "monochrome" once at your app's entry point. The wrappers generate the correct HTML structure and ARIA attributes. All interactivity comes from the Monochrome runtime - no framework JavaScript needed on the client.

The Vue API is identical: import { Accordion } from "monochrome/vue". Monochrome also works with plain HTML or any framework that outputs HTML. See AGENTS.md for full documentation.

Components

Four interactive UI patterns in 2.2kB:

Component	Description	Tests
Accordion	Grouped collapsible content sections	66
Collapsible	Show and hide content with a button	42
Menu	Dropdown menus, menubars, and submenus	176
Tabs	Switch between multiple content panels	70

How it works

Monochrome uses the DOM as its source of truth. Instead of managing state in JavaScript, it reads ARIA attributes, responds to user interactions, and updates them directly. Minimal global event listeners handle every component on the page through event delegation. No initialization, no configuration, no framework required.

Accessibility

Every component follows WAI-ARIA Authoring Practices and targets WCAG 2.2 AA:

• Full keyboard navigation (Arrow keys, Home, End, Enter, Space, Escape)
• Roving tabindex for focus management
• Automatic ARIA attribute management
• Preserves browser find-in-page (cmd+f)
• Screen reader support out of the box

Styling

Monochrome is headless - no CSS is shipped. You provide all styles. Key requirements for menus:

[popover]:popover-open {
  display: flex;
}

[role="menu"] {
  position: fixed;
  top: var(--bottom);
  left: var(--left);
}

[role="menu"] [role="menu"] {
  top: var(--top);
  left: var(--right);
}

Browser Requirements

The core depends on Popover API and hidden="until-found" (Baseline 2024). All modern browsers are supported.

License

MIT © Colin van Eenige