@kbach/native

Tailwind-like utility classes for React Native and Expo. One package includes everything: the core engine, JSX runtime, and Babel preset. Classes are written as className strings and resolved to inline styles at render time.

import { View, Text, TouchableOpacity } from 'react-native';
import { styled } from '@kbach/native';

const Button = styled(
  TouchableOpacity,
  'bg-blue-7 pressed:bg-blue-8 dark:bg-indigo-6 rounded-xl px-6 py-3 items-center'
);

export default function Screen() {
  return (
    <View className="flex-1 bg-gray-2 dark:bg-gray-11 p-4">
      <Text className="text-2xl font-bold text-gray-10 dark:text-white mb-4">
        Hello Kbach
      </Text>
      <Button>
        <Text className="text-white font-semibold">Press me</Text>
      </Button>
    </View>
  );
}

Install

npm package

npm install @kbach/native

Setup

1. babel.config.js

One-liner using the helper:

const { createKbachConfig } = require('@kbach/native');
module.exports = createKbachConfig();

Or manually:

module.exports = function (api) {
  api.cache(true);
  return {
    presets: [
      ['babel-preset-expo', { jsxImportSource: '@kbach/native' }],
      '@kbach/native/babel',
    ],
  };
};

Merging into an existing Babel config:

const { withKbachBabel } = require('@kbach/native');

module.exports = withKbachBabel({
  presets: ['babel-preset-expo'],
  plugins: [/* your existing plugins */],
});

After changing babel.config.js, clear the Metro cache:

npx expo start --clear

2. Wrap your app

import { ThemeProvider } from '@kbach/native';

export default function App() {
  return (
    <ThemeProvider defaultMode="system">
      <AppContent />
    </ThemeProvider>
  );
}

ThemeProvider reads useColorScheme() and useWindowDimensions() automatically — no extra props needed.

API

className / kb prop

Works on any React Native component — View, Text, TouchableOpacity, TextInput, and third-party components.

<View className="flex-1 bg-gray-2 dark:bg-gray-11 p-4" />
<Text className="text-lg font-bold text-gray-10 dark:text-white" />
<TouchableOpacity className="bg-blue-7 pressed:bg-blue-8 rounded-xl px-6 py-3" />

styled(Component, classes)

Pre-style any component. Handles interaction states (pressed:, focus:, etc.) automatically. Pass extra classes at use time with the kb prop.

import { styled } from '@kbach/native';
import { View, Text, TouchableOpacity, TextInput } from 'react-native';

const Card = styled(View, 'bg-white dark:bg-gray-9 rounded-2xl p-6 shadow');
const Title = styled(Text, 'text-2xl font-bold text-gray-10 dark:text-white');
const Button = styled(
  TouchableOpacity,
  'bg-blue-7 pressed:bg-blue-8 dark:bg-indigo-6 dark:pressed:bg-indigo-7 rounded-xl px-6 py-3'
);
const Input = styled(
  TextInput,
  'border border-gray-4 dark:border-gray-7 focus:border-blue-6 bg-white dark:bg-gray-8 rounded-lg px-4 py-3'
);

<Card kb="mt-4 mb-2">
  <Title kb="text-3xl">Hello</Title>
</Card>

cx(...classes)

Conditionally join class strings. Falsy values are ignored.

import { cx } from '@kbach/native';

<View className={cx(
  'p-4 rounded-xl border',
  isSelected ? 'border-blue-6 bg-blue-1' : 'border-gray-3 bg-white',
  isDisabled && 'opacity-50',
)} />

useStyles(classes, state?)

Resolve classes to a style object inside a component.

import { useStyles } from '@kbach/native';
import { View, Text } from 'react-native';

function Badge() {
  const containerStyle = useStyles('bg-blue-6 dark:bg-indigo-6 px-3 py-1 rounded-full');
  const textStyle = useStyles('text-white text-xs font-bold');
  return (
    <View style={containerStyle}>
      <Text style={textStyle}>New</Text>
    </View>
  );
}

// With interaction state
const [pressed, setPressed] = useState(false);
const style = useStyles('bg-blue-5 pressed:bg-blue-7 rounded-lg', { pressed });

kb(classes)

Resolve classes outside a component, for StyleSheet.create() or static contexts.

import { StyleSheet } from 'react-native';
import { kb } from '@kbach/native';

const styles = StyleSheet.create({
  container: kb('flex-1 bg-white p-4') as object,
  title:     kb('text-2xl font-bold text-gray-10') as object,
});

useTheme()

import { useTheme } from '@kbach/native';

const { mode, resolvedMode, isDark, setMode, toggle, config } = useTheme();

| Value | Type | Description | |---|---|---| | mode | 'light' \| 'dark' \| 'system' | User-selected mode | | resolvedMode | 'light' \| 'dark' | Resolved after system lookup | | isDark | boolean | Shorthand for resolvedMode === 'dark' | | setMode | fn | Set mode explicitly | | toggle | fn | Toggle between light and dark | | config | ResolvedConfig | Full resolved config |

useIsDark()

import { useIsDark } from '@kbach/native';
const isDark = useIsDark();

useColors()

Returns the active theme's color palette as a smart proxy.

import { useColors } from '@kbach/native';

const colors = useColors();
colors.blue[6]              // '#3b82f6'
colors.blue['6/50']         // 'rgba(59,130,246,0.5)'
colors.white                // '#ffffff'
colors['white/20']          // 'rgba(255,255,255,0.2)'
colors.alpha('#ff6b35', 60) // 'rgba(255,107,53,0.6)'

Modifiers

Chain modifiers in any order before the utility name:

<View className="dark:sm:pressed:bg-blue-8" />

Theme

| Modifier | Trigger | |---|---| | dark: | Dark mode | | light: / not-dark: | Light mode |

Interactive

| Modifier | Trigger | |---|---| | pressed: | Touch / click pressed | | focus: | Element focused | | hover: | Mouse hover (React Native Web) | | active: | Active state | | disabled: | Disabled | | checked: | Checked |

Negated: not-pressed:, not-focus:, not-hover:, not-active:, not-disabled:, not-checked:

Responsive

Resolved from current window width via useWindowDimensions().

| Modifier | Min-width | |---|---| | sm: | 576 px | | md: | 768 px | | lg: | 1024 px | | xl: | 1280 px | | 2xl: | 1536 px |

<View className="p-4 md:p-8 lg:p-12" />

Important

<View className="!p-0 !m-0" />

Arbitrary values

<View className="bg-[#6366f1]" />
<View className="p-[14px]" />
<Text className="text-[18px]" />
<View className="rounded-[20px]" />
<View className="w-[200px]" />

Negative values

<View className="-mt-4" />      // marginTop: -16
<View className="-mx-2" />      // marginHorizontal: -8
<View className="-mt-[10px]" /> // marginTop: -10

Color system

12-shade scale — 1 lightest, 12 darkest. Use as bg-blue-6, text-gray-10, border-red-4/50.

Families: slate gray zinc neutral stone red orange amber yellow lime green emerald teal cyan sky blue indigo violet purple fuchsia pink rose
Special: transparent black white

Opacity modifier: bg-blue-6/50 (50% alpha)

Native-only utilities

| Utility | Effect | |---|---| | tint-{color} | tintColor on Image / icon components | | perspective-{n} | 3-D perspective transform | | backface-hidden | backfaceVisibility: hidden | | text-shadow | Text shadow (small) | | text-shadow-lg | Text shadow (large) |

<Image source={icon} className="tint-blue-6 w-6 h-6" />
<View className="perspective-500 rotate-y-45" />
<Text className="text-shadow font-bold">Shadowed</Text>

Expo Web / React Native Web

When the bundle runs in a browser (Expo Web, Metro web target), @kbach/native automatically switches to the same CSS-class strategy as @kbach/react:

• React Native components are substituted with semantic HTML elements:

| Component | HTML tag | |---|---| | View, ScrollView, SafeAreaView | div | | Text | span | | TextInput | input / textarea (multiline) | | Image | img | | Pressable, TouchableOpacity | div (role="button") | | FlatList, SectionList | div |

• CSS classes are applied instead of inline styles — the same kbach.css approach as @kbach/react.
• React Native–only props (onChangeText, source, secureTextEntry, keyboardType, etc.) are mapped to their HTML equivalents.
• To register additional components: registerWebElement(Animated.View, 'div').

To use the Vite plugin on an Expo Web project, add it to vite.config.ts:

import { kbach } from '@kbach/react/vite';

export default defineConfig({
  plugins: [kbach()],
});

Create and import kbach.css in your entry file exactly as in the @kbach/react setup.

Web-only utilities (gracefully ignored on native)

These resolve to null on React Native and produce no warning:

caret-*, accent-*, touch-*, float-*, clear-*, line-clamp-*, scroll-*, animate-*, transition, filter, backdrop-filter, print:, before:, after:, selection:, first-letter:, first-line:, marker:, landscape:, portrait:, motion-reduce:, motion-safe:, contrast-more:, contrast-less:, rtl:, ltr:, grid, grid-cols-*, ring, outline-*, cursor-*, bg-gradient-*

Configuration

// kbach.config.js
module.exports = {
  darkMode: 'attribute', // 'attribute' | 'class' | 'media'

  theme: {
    colors: { brand: { 1: '#eff6ff', 6: '#3b82f6', 10: '#1e3a5f' } },
  },

  extend: {
    colors: { brand: { 6: '#6366f1' } },
    spacing: { 18: 72 },
    screens: { '3xl': 1920 },
    fontFamily: {
      sans:        'CormorantGaramond_400Regular',
      'sans-md':   'CormorantGaramond_500Medium',
      'sans-bold': 'CormorantGaramond_700Bold',
    },
  },

  plugins: [
    ({ addUtility, addVariant, theme }) => {
      addUtility('border-brand', {
        borderColor: theme('colors.brand.6'),
        borderWidth: 2,
      });
      addVariant('long-press', {
        pseudo: ':active',
        jsBehavior: 'interactive',
        jsMatch: (_, state) => !!state.longPressed,
      });
    },
  ],
};

CSS inheritance does not exist in React Native. Apply font utilities to each Text, or define styled components once:

const Body    = styled(Text, 'font-sans text-gray-10 dark:text-white');
const Heading = styled(Text, 'font-sans-bold text-2xl text-gray-10 dark:text-white');

Full reference

See kbach-native.md for the complete utility reference, native-only utilities, and configuration options.