🎨 react-theming-engine

A production-ready, lightweight React theming engine that bridges the gap between Brand Palettes, Semantic Tokens, and CSS Variables. Built for high-performance design systems.

🌐 Live Docs & Interactive Playground

Try it live → react-theme-engine.vercel.app

Explore the full interactive documentation, switch between all built-in theme presets, tweak primary colors in real time, and copy integration code — all in one place.

npm install react-theming-engine

✨ Features

• 🏗️ 3-Layer Architecture: Brand Palette → Semantic Tokens → CSS Variables.
• 🌓 Dynamic Modes: Native Light and Dark support with smart palette migration.
• 🎨 Runtime Branding: Change primary colors or overrides on-the-fly with overrideTheme.
• ⚡ Zero-Runtime Overhead: Styles are applied via CSS variables for maximum performance.
• 🌪️ Tailwind Friendly: Includes a first-class preset for utility-first workflows.
• 🔒 Type-Safe: Full TypeScript support with exported types for all tokens.

🛠️ Technology Stack

• React (^18.0.0): Core UI library.
• TypeScript (^5.7.0): Strongly typed programming.
• tsup: High-performance library bundler.
• Styling Flexibility: Seamlessly integrate with Vanilla CSS, SCSS, CSS-in-JS, or Tailwind CSS.

📦 Installation

npm install react-theming-engine

🚀 Quick Start

1. Initialize the Provider

The ThemeProvider handles state, persistence, and DOM variable injection.

import { ThemeProvider } from 'react-theming-engine';

function App() {
  return (
    <ThemeProvider defaultThemeName="light" storageKey="app-theme">
      <MainLayout />
    </ThemeProvider>
  );
}

2. Implementation Options

Option A: Vanilla CSS (Recommended for Flexibility)

The engine automatically injects variables like --color-background and --color-accent into the :root.

/* In your CSS files */
.my-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

.my-text {
  color: var(--color-foreground-muted);
}

Option B: Tailwind CSS

Add the preset to your config to use tokens as utility classes.

/* tailwind.config.js */
import { themePreset } from 'react-theming-engine/tailwind';

export default {
  content: ["./src/**/*.{ts,tsx}"],
  presets: [themePreset],
}

Usage: <div className="bg-surface text-foreground-muted rounded-md" />

🎨 Color Utilities

The engine exports a rich suite of pure, framework-agnostic utilities to help you work with colors at runtime. These are perfect for calculating hovestates, generating dynamic contrasts, or checking OS preferences.

import { 
  lighten, 
  darken, 
  withOpacity, 
  getContrastRatio, 
  prefersDarkMode,
  hexToHsl
} from 'react-theming-engine';

// 🔄 Intelligent Manipulation
const hoverColor = lighten('#2563eb', 10);
const mutedBg = withOpacity('#2563eb', 0.1); // Returns #2563eb1a

// ♿ Accessibility & Intelligence
const ratio = getContrastRatio('#ffffff', '#2563eb'); // Result: 5.89 (Passes WCAG AA)
const isDarkMode = prefersDarkMode(); // Boolean based on OS preference

// 🔄 Advanced Conversion
const hsl = hexToHsl('#2563eb'); // Returns { h: 221, s: 83, l: 53 }

🛠️ Available Functions

🏗️ Dynamic Branding (Advanced)

You can apply logic-based overrides at any time. This is perfect for "Primary Color Changers" or user-specific branding.

const { overrideTheme } = useTheme();

const updateBrandColor = (newHex: string) => {
  overrideTheme({
    tokens: {
      accent: newHex,
      accentHover: `${newHex}cc`, // 80% opacity
    }
  });
};

🌈 Included Presets

🏗️ Architecture Detail

We use a 3-Layer System to ensure UI logic never touches hardcoded colors:

1. Brand Palette: Raw color scales (e.g. blue-500).
2. Semantic Tokens: Functional roles (e.g. accent → brand.primary.600).
3. CSS Variables: The final performance-focused output.

📖 Documentation

• Theming Guide - Deep dive into tokens and overrides.
• Publishing Guide - NPM & GitHub Package instructions.
• Contributing Guidelines

👨‍💻 Meet the Maintainer

Built with ❤️ by Abilash. A UI Engineer focused on scalable design systems and developer tools.

📜 License

MIT © Abilash