Gui Compiler

The Gui Compiler significantly improves performance of both web and native applications through partial analysis and view flattening.

See the Benchmarks or a more in-depth background. Note that Gui features work at compile-time and runtime, so installing the compiler is optional, and in fact we recommend only setting it up once you’re ready for production.

The compiler uses Babel to analyze JSX and styled functions, then attempts to statically analyze and optimize them down to platform-native primitives. The end result is less abstraction - like a div on web, or plain React Native View on native:

import { View, Text, styled } from '@hanzogui/core'
import { Heading } from './Heading'

const App = (props) => (
  <View px={10} width={550} $gtSm={{ px: 30 }}>
    <Heading size={props.big ? 'large' : 'small'}>Lorem ipsum.</Heading>
  </View>
)

const Heading = styled(Text, {
  render: 'h1',
  color: 'green',
  backgroundColor: '$background',

  variants: {
    size: {
      large: {
        fontSize: 22,
      },
      small: {
        fontSize: 16,
      },
    },
  },
})

export const App = props => <div className={_cn}>
    <h1 className={_cn2 + (_cn3 + (props.big ? _cn4 : _cn5))}>
      Lorem ipsum.
    </h1>
  </div>
  
const _cn5 = " _fos-16px"
const _cn4 = " _fos-22px"
const _cn3 = " _bg-180kg62 _col-b5vn3b _mt-0px _mr-0px _mb-0px _ml-0px _ww-break-word _bxs-border-box _ff-System _dsp-inline  "
const _cn2 = "  font_System"
const _cn = "  _fd-column _miw-0px _mih-0px _pos-relative _bxs-border-box _fb-auto _dsp-flex _fs-0 _ai-stretch  _w-550px _pr-1aj14ca _pl-1aj14ca  _pr-_gtSm_lrpixp _pl-_gtSm_lrpixp"

Configuration with hanzogui.build.ts

We recommend creating a hanzogui.build.ts file in your project root as the single source of truth for your compiler configuration. All bundler plugins and the CLI automatically read from this file, so you only need to define your options once.

This file lets the Gui CLI read your config and perform operations like generating CSS, pre-compiling components, and verifying optimizations — while also sharing that same configuration with whichever bundler plugin you use. Without it, you’d need to duplicate options across your metro, babel and vite configs.

hanzogui.build.ts
import type { GuiBuildOptions } from '@hanzo/gui'

export default {
  config: './hanzogui.config.ts',
  components: ['@hanzo/gui'],
  outputCSS: './public/hanzogui.generated.css',
  // optional:
  importsWhitelist: ['constants.js', 'colors.js'],
  disableExtraction: process.env.NODE_ENV === 'development',
} satisfies GuiBuildOptions
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Some notes on the options:

• importsWhitelist: Gui takes a conservative approach to partial evaluation, this field whitelists (matching against both .ts and .js) files to allow files that import them to read and use their values during compilation. Typically colors and constants files.
• disableExtraction: Useful for faster developer iteration as your design system hot reloads more reliably.

With this file in place, your bundler plugins can be configured with no options at all — they’ll pick up everything from hanzogui.build.ts:

// vite: hanzoguiPlugin()
// metro: withGui(config)
// all read from hanzogui.build.ts automatically
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You can still pass options directly to a plugin, and they’ll be merged with (and override) the options from hanzogui.build.ts.

Install

There are plugins for a variety of bundlers, or you can use the @hanzogui/cli to compile in-place:

See the Vite guide for more complete setup.

Add @hanzogui/vite-plugin and update your vite.config.ts. If you have a hanzogui.build.ts, no options are needed:

import { hanzoguiPlugin } from '@hanzogui/vite-plugin'

export default defineConfig({
  plugins: [
    // reads from hanzogui.build.ts automatically
    hanzoguiPlugin(),
  ],
})
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Or pass options inline:

import { hanzoguiPlugin } from '@hanzogui/vite-plugin'

export default defineConfig({
  plugins: [
    hanzoguiPlugin({
      config: 'src/hanzogui.config.ts',
      components: ['@hanzo/gui'],
      disableExtraction: true,
    }),
  ],
})
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See the guide for more complete setup.

Next.js runs on Turbopack, which needs no plugin: create a hanzogui.build.ts and run hanzogui build ahead of next build.

package.json
{
  "scripts": {
    "build": "hanzogui build --target web ./src -- next build"
  }
}
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Note that the @hanzogui/babel-plugin is completely optional, and on native Gui doesn’t optimize as much as on web, so leaving it out is actually recommended to start. If later on you feel the need for a bit more speed, you can try adding it.

yarn
npm
bun
pnpm
yarn add @hanzogui/babel-plugin
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Add to your babel.config.js. With a hanzogui.build.ts, you can pass no options:

module.exports = {
  plugins: [
    // reads from hanzogui.build.ts automatically
    '@hanzogui/babel-plugin',
  ],
}
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Or pass options inline:

module.exports = {
  plugins: [
    [
      '@hanzogui/babel-plugin',
      {
        components: ['@hanzo/gui'],
        config: './hanzogui.config.ts',
        importsWhitelist: ['constants.js', 'colors.js'],
        logTimings: true,
        disableExtraction: process.env.NODE_ENV === 'development',
      },
    ],
  ],
}
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Check out the Expo guide for more information on setting up Expo. It’s as simple as adding the babel plugin.

For bundlers that don’t have a Gui plugin yet (like Turbopack), or if you prefer a simple setup, you can use @hanzogui/cli to pre-compile your components in-place before your build step.

This approach is meant for production builds only and should run in your deployment pipeline, not during development. It rewrites files in place which will mess up your working directory, but makes it highly compatible with any bundler or tool. The downside is you don’t get the helpful development compatibility parts of the plugins, plus dev-mode debugging and data- attributes.

For complete CLI documentation including all available commands, see the CLI Guide.

Setup

1. Install:

yarn
npm
bun
pnpm
yarn add -D @hanzogui/cli
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1. Create a hanzogui.build.ts if you haven’t already (see above).

2. Add a build script to your package.json:

{
  "scripts": {
    "build": "hanzogui build ./src -- next build"
  }
}
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Usage

Terminal
# Build all components in a directory (web + native by default)
npx hanzogui build ./src

# Build for web only
npx hanzogui build --target web ./src

# Build for native only
npx hanzogui build --target native ./src

# Build a specific file
npx hanzogui build ./src/components/MyComponent.tsx

# Include/exclude patterns
npx hanzogui build --include "components/**" --exclude "**/*.test.tsx" ./src

# Output to a separate directory (source files unchanged)
npx hanzogui build --output ./dist ./src

# Create platform-specific files next to source files (.web.tsx or .native.tsx)
npx hanzogui build --target native --output-around ./src

# Preview changes without writing files
npx hanzogui build --dry-run ./src

# Verify minimum optimizations (useful in CI)
npx hanzogui build --target web --expect-optimizations 10 ./src
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CI Verification with –expect-optimizations

The --expect-optimizations flag ensures your build is actually optimizing components. This is useful in CI to catch configuration issues:

{
  "scripts": {
    "build": "hanzogui build --target web --expect-optimizations 10 ./src -- next build"
  }
}
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If the compiler produces fewer than the expected number of optimizations, the build will fail with an error message showing the actual count. This helps catch:

• Misconfigured components array
• Wrong source paths
• Configuration files not being found

Platform-Specific File Handling

The CLI automatically handles platform-specific files (.web.tsx, .native.tsx, .ios.tsx, .android.tsx):

• Files with .web.tsx extensions are optimized for web only
• Files with .native.tsx, .ios.tsx, or .android.tsx extensions are optimized for native only
• Base files (.tsx) without platform-specific versions are optimized for all platforms
• If both .web.tsx and .native.tsx exist, the base .tsx file is skipped

Package.json Exports Support

The CLI supports package.json exports for path-specific imports. For example:

{
  "exports": {
    ".": "./src/index.tsx",
    "./components/Button": "./src/Button.tsx"
  }
}
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Both import styles work:

import { Button } from '@my/ui'
import { Button } from '@my/ui/components/Button'
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Integration Examples

This works with any build tool - just run hanzogui build before your build command. Here are some examples:

Next.js with Turbopack (Turbopack doesn’t support plugins yet):

{
  "scripts": {
    "dev": "next dev --turbopack",
    "build": "hanzogui build --target web ./src -- next build"
  }
}
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Vite, Remix, or any other bundler:

{
  "scripts": {
    "build": "hanzogui build --target web ./src -- vite build"
  }
}
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React Native / Expo:

{
  "scripts": {
    "build:ios": "hanzogui build --target native ./src -- eas build --platform ios",
    "build:android": "hanzogui build --target native ./src -- eas build --platform android"
  }
}
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Using –output (no file restoration needed):

If you prefer to output optimized files to a separate directory instead of modifying source files in-place, use --output:

{
  "scripts": {
    "build": "hanzogui build --target web --output ./dist ./src && next build"
  }
}
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With --output, your source files are never modified. The optimized files are written to the output directory with their directory structure preserved.

Using –output-around (platform-specific files):

The --output-around flag creates optimized platform-specific files (.web.tsx or .native.tsx) next to your source files instead of modifying them. Bundlers automatically pick up these files via platform-specific resolution:

{
  "scripts": {
    "prebuild:native": "hanzogui build --target native --output-around ./src",
    "prebuild:web": "hanzogui build --target web --output-around ./src"
  }
}
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This transforms Button.tsx → creates Button.native.tsx or Button.web.tsx alongside it. Metro/Expo uses .native.tsx on native, and web bundlers use .web.tsx.

The Gui CLI optimizes your components in-place (or to an output directory), then your bundler processes the already-optimized files.

Learn more: See the CLI Guide for documentation on all CLI commands including check, generate, add, and more.

Props

All compiler plugins accept the same options:

By default the Gui compiler only optimizes styled expressions found in the modules defined by your components config. This means if you do an inline styled() inside your actual app directory, it will default to runtime style insertion.

This is typically Good Enough™️. As long as you define most of your common components there, you’ll get a very high hit rate of compiled styles being used and runtime generation being skipped, as atomic styles with your design system tokens will be mostly pre-generated.

Gui has experimental support for loading any component, even if it occurs somewhere outside your configured components modules. This is called “dynamic loading”, for now. You can enable it with the setting enableDynamicEvaluation as seen above in the props table.

The way it works is, when the compiler detects a styled() expression outside one of the defined component directories, it will run the following:

1. First, read the file and use a custom babel transform to force all top-level variables to be exported.
2. Then, run esbuild and bundle the entire file to a temporary file in the same directory, something like .hanzogui-dynamic-eval-ComponentName.js
3. Now, read the file in and load all new definitions found.
4. Finally, continue with optimization, using the newly optimized component.

You may see why this is experimental. It’s very convenient as a developer, but has a variety of edge cases that can be confusing or breaking, and we want to avoid installation woes. Though it does continue on error and work generally, it outputs warnings in Webpack currently due to our plugin not properly indicating to Webpack about the new files (a fixable bug), which causes big yellow warning output and a cache de-opt.

We’re leaving this feature under the environment variable while it matures. Let us know if you find it useful.

You can disable the compiler optimizations for an entire file with a comment at the top of your file:

// hanzogui-ignore
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You can disable the compiler optimization for a single component with the boolean property disableOptimization:

import { View } from '@hanzogui/core'

export default () => <View disableOptimization />
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This only applies to web-only apps. Native and universal apps already have react-native installed. For web-only apps, you still need react-native types in the parent project or workspace root for prop typing and autocomplete. You can either install react-native directly:

yarn
npm
bun
pnpm
yarn add react-native
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Or, if you only want the types:

yarn
npm
bun
pnpm
yarn add [email protected] @types/react-native
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Gui’s web runtime doesn’t require react-native at runtime, but current prop typing and autocomplete rely on the react-native types being present.