@meonode/ui

Type-safe React components without JSX

A production-ready component library that replaces JSX with function-based composition, featuring direct CSS prop styling, context-based theming, automatic memoization, and full React Server Components support—powered by @emotion/react.

Core Concept

MeoNode UI eliminates JSX while maintaining full React compatibility through functional composition. Style components with CSS properties as props, leverage automatic theme resolution via React Context, and benefit from intelligent caching without manual optimization.

JSX Pattern:

<div style={{ padding: '20px', borderRadius: '12px' }}>
  <h2 style={{ fontSize: '1.5rem', marginBottom: '8px' }}>{title}</h2>
  {children}
</div>

MeoNode Pattern:

Div({
  padding: '20px',
  borderRadius: '12px',
  backgroundColor: 'theme.primary',
  children: [H2(title, { fontSize: '1.5rem', marginBottom: '8px' }), ...children],
})

Features

Function-Based Composition

Plain JavaScript functions replace JSX—no build transforms, no syntax extensions. Compose UIs as first-class function trees with full TypeScript inference.

Nothing here requires a build step. An optional build-time plugin exists purely as an optimization—see Optional Build-Time Compiler.

Direct CSS-in-Props

Pass CSS properties directly to components. No separate styled-components declarations, no className juggling. All valid CSS properties work as props with full type safety.

Button('Submit', {
  padding: '12px 24px',
  backgroundColor: 'theme.primary',
  borderRadius: 8,
  transition: 'all 0.2s ease',
  css: {
    ':hover': { transform: 'scale(1.05)' },
  },
})

Advanced Portal System

Manage complex UI layers like modals, drawers, and overlays with a powerful stack-based portal system. Supports nested portals and state synchronization.

Key Features:

• Global Layout Integration: Define the provider and host at the root for app-wide access.
• Auto-Sync: Keep portal content in sync with parent state automatically.
• Nested Portals: Open portals from within other portals easily.
• Stack-based management: Automatically manages multiple overlapping layers.

// 1. Setup at Layout Level
const RootLayout = ({ children }: { children: ReactNode }) => 
  PortalProvider({
    children: [
      ...children,
      PortalHost() // Portals render here, on top of content
    ]
  })

// 2. Define data interface and portal content
interface MyData {
  count: number;
  setCount: React.Dispatch<React.SetStateAction<number>>;
}

const MyPortalContent = ({ data, close }: PortalLayerProps<MyData>) => 
  Div({
    children: [
      Text(`Count: ${data?.count}`),
      Button('Increment', { onClick: () => data?.setCount(c => c + 1) }),
      Button('Close', { onClick: close })
    ]
  })

// 3. Use anywhere in the tree
const MyComponent = () => {
  const [count, setCount] = useState(0)
  // Auto-sync: portal updates whenever count changes
  const portal = usePortal<MyData>({ count, setCount })

  return Div({
    children: [
      Button('Open Modal', { 
        onClick: () => portal.open(MyPortalContent) 
      })
    ]
  })
}

Context-Based Theming

Theme values resolve automatically through React Context. Reference semantic tokens anywhere without prop drilling. Supports nested themes and dynamic switching.

ThemeProvider({
  theme: {
    mode: 'dark',
    system: {
      primary: { default: '#FF6B6B', content: '#4A0000' },
      spacing: { sm: 8, md: 16, lg: 24 },
    },
  },
  children: [
    /* your app */
  ],
})

Surgical Memoization

Memoize at node-level granularity—not just entire components. Control re-renders with precision by specifying dependency arrays directly on individual nodes.

Node-Level Memoization:

const UserCard = ({ user }) =>
  Div(
    {
      padding: 16,
      children: [
        H2(user.name), // Re-renders on any prop change
        Text(user.bio),
      ],
    },
    [user.id],
  ).render() // Only re-render when user.id changes

Component-Level Memoization:

Node(ExpensiveComponent, { data }, [data.id]).render()

React Server Components Compatible

Full RSC support with proper client/server component boundaries. Use in Next.js App Router, Remix, or any RSC-enabled environment without configuration.

Emotion-Powered Styling

Built on @emotion/react for:

• Automatic critical CSS extraction
• Vendor prefixing
• Dead code elimination
• Server-side rendering support

Smart Prop Differentiation

Automatically separates style props from DOM attributes. Pass onClick, aria-*, data-* alongside CSS props—MeoNode routes them correctly.

Button('Click Me', {
  padding: '12px', // → style
  color: 'theme.primary', // → style
  onClick: handleClick, // → DOM attribute
  'aria-label': 'Submit', // → DOM attribute
  disabled: isLoading, // → DOM attribute
})

Debug Mode

Every diagnostic in the library sits behind one runtime flag, off by default.

import { setDebugMode } from '@meonode/ui'

setDebugMode(true)

Set it at module scope in your entry file, not in a useEffect — a few messages fire when the first node is constructed and an effect runs too late to catch them.

It surfaces cache eviction and memoization activity, SPA navigation cleanup, oversized prop objects, malformed @meonode/compiler markers, and errors thrown inside function-as-a-child that are otherwise swallowed. Useful when a memoized node renders stale content, memory grows across navigations, or a deps array is not behaving.

The output ships in production builds — the flag is a runtime binding, not a build-time constant, so bundlers cannot strip it. That is deliberate: the bugs worth this much logging are usually the ones that only reproduce in production. It costs about 0.5 KB gzipped.

📖 Full list of what it logs

Performance Benchmarks

MeoNode is built for high-performance applications, featuring an optimized caching system and iterative rendering engine.

How to read these numbers. They come from bun run bench, which runs in jsdom on Node, not a browser. They are microbenchmarks against production React, and absolute timings move with hardware, Node version and background load — 10–20% run-to-run spread on one machine is normal. Treat them as orders of magnitude and as regression guards, not precise figures. Reproduced on an Apple M4 Pro / 24 GB / Node 26 / React 19.2, taking medians of alternating rounds.

Production React matters: these previously ran under vitest, which forces NODE_ENV=test and so measured React's development build. Its validation overhead is large enough to swamp the library — it reported the compiler's client-side gain as 1.03x where the real figure is ~1.4x.

Layout Rendering

| Metric | Value | Description | |:------------------------|:---------|:----------------------------------------------------| | Single-Page Layout | ~2 ms | Full page layout with header, sections and footer | | 10,000 Flat Nodes | ~65 ms | Rendering 10k nodes at the same level | | 10,000 Nested Nodes | ~1200 ms | Deeply nested structure (single parent-child chain) |

The nesting case doubles as a stack-safety check: render() walks iteratively with an explicit work stack precisely so 10,000 levels do not overflow the call stack.

Memory Management

Heap growth measured after a forced collection, against the ceiling each check asserts:

| Check | Growth | Ceiling | |:-----------------------------------|:------------|:---------| | 50 heavy state updates | ~2.5 MB | 150 MB | | 200 mounts/unmounts over 20 cycles | ~14 MB | 20 MB | | 10 navigation cycles | ~1.6 MB | 20 MB |

bench/memory.mjs exits non-zero if any ceiling is exceeded, so it works as a leak gate you run deliberately.

React Comparison (10k flat nodes, one style property)

| Implementation | Time | |:------------------------------|:---------| | React.createElement | ~44 ms | | React.createElement+Props | ~85 ms | | MeoNode | ~41 ms | | MeoNode+Props | ~93 ms |

Read the bold rows. Bare React.createElement does no prop work at all, while MeoNode always classifies props into CSS vs DOM attributes and computes a stable key. Against the like-for-like pair MeoNode is ~1.09x slower — and roughly at parity (~1.0x) on the 5,000-node nested case.

The style object is kept to a single property on purpose. React writes inline style properties onto the DOM node one at a time while MeoNode emits a single Emotion class, so a larger style object inflates React's side — with three properties this table would show MeoNode as 3x faster, which would be a measurement artifact rather than a result.

Quick Start

import { ThemeProvider, Center, Column, H1, Button, Text } from '@meonode/ui'

const theme = {
  mode: 'light',
  system: {
    primary: { default: '#FF6B6B', content: '#FFFFFF' },
    base: { default: '#F8F8F8', content: '#333333' },
  },
}

const App = () =>
  ThemeProvider({
    theme,
    children: [
      Center({
        padding: 40,
        backgroundColor: 'theme.base',
        children: Column({
          gap: 24,
          children: [
            H1('MeoNode UI', {
              fontSize: '3rem',
              color: 'theme.primary',
            }),
            Text('Type-safe React without JSX', {
              fontSize: '1.2rem',
              color: 'theme.base.content',
            }),
            Button('Get Started', {
              backgroundColor: 'theme.primary',
              color: 'theme.primary.content',
              padding: '12px 24px',
              borderRadius: 8,
              cursor: 'pointer',
              onClick: () => console.log('Started!'),
            }),
          ],
        }),
      }),
    ],
  }).render()

Architecture

Component Factory System Node factory + Component wrapper + semantic elements (Div, Button, etc.) enable both rapid prototyping and sophisticated component architectures.

Theme Resolution Engine Context-based theme propagation with automatic value resolution. Nested theme objects inherit and override parent values without explicit passing.

CSS Engine @emotion/react provides CSS-in-JS with automatic optimization, critical CSS extraction for SSR, and zero-runtime overhead in production builds.

Why MeoNode UI?

For Teams Building Design Systems:

• Context-based theme propagation
• Semantic token system ensures visual consistency
• Component composition patterns scale naturally
• Full TypeScript support catches design token errors

For Performance-Critical Applications:

• Emotion's CSS optimization and caching
• Surgical memoization at node granularity
• SSR-ready with critical CSS extraction
• RSC compatibility for modern React architectures

For Developer Productivity:

• No JSX compilation overhead
• Direct CSS-in-props reduces context switching
• Intelligent prop routing (style vs DOM attributes)
• Full autocomplete for all CSS properties
• Composable function trees with first-class JavaScript

Documentation

📚 Complete Documentation & Examples

🎮 Interactive Playground

Contributing

We welcome contributions! Please see our contributing guidelines.

License

MIT © Ukasyah Rahmatullah Zada

📖 Full Documentation • 🐛 Issues • * 💬 Discussions*