Bun

examples/example-bun demonstrates using StyleX with Bun and @stylexjs/unplugin.

For production builds, Bun can use the unplugin esbuild adapter through Bun.build(). For Bun's dev server, StyleX also provides a dedicated Bun plugin entrypoint.

Install

npm install --save-dev @stylexjs/unplugin

pnpm add -D @stylexjs/unplugin

yarn add -D @stylexjs/unplugin

bun add -D @stylexjs/unplugin

Production builds with Bun.build()

import stylex from '@stylexjs/unplugin';

await Bun.build({
  entrypoints: ['src/main.jsx'],
  outdir: 'dist',
  target: 'browser',
  metafile: true,
  plugins: [
    stylex.esbuild({
      useCSSLayers: true,
      importSources: ['@stylexjs/stylex'],
      unstable_moduleResolution: { type: 'commonJS' },
    }),
  ],
});

• metafile: true lets the plugin locate Bun's emitted CSS asset.
• useCSSLayers: true wraps the generated StyleX output in @layer blocks.

Bun dev server

Add the Bun plugin entrypoint in bunfig.toml:

[serve.static]
plugins = ["@stylexjs/unplugin/bun"]

The Bun plugin writes generated StyleX CSS to a dev stylesheet so Bun can reload it during development.

CSS entrypoint

As with the other bundler integrations, make sure your app imports a CSS file from the root entry so Bun emits a stylesheet for StyleX to append to during production builds.