Make JS APIs available to plugins and configs in the Standalone CLI

CHANGELOG.md

@@ -15,6 +15,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- Make JS APIs available to plugins and configs in the Standalone CLI ([#15934](https://github.com/tailwindlabs/tailwindcss/pull/15934))
 - Vite: Don't crash when importing a virtual module in JavaScript that ends in `.css` ([#16780](https://github.com/tailwindlabs/tailwindcss/pull/16780))
 
 ## [4.0.8] - 2025-02-21

integrations/cli/standalone.test.ts

@@ -1,6 +1,6 @@
 import os from 'node:os'
 import path from 'node:path'
-import { candidate, css, html, json, test } from '../utils'
+import { candidate, css, html, js, json, test } from '../utils'
 
 const STANDALONE_BINARY = (() => {
   switch (os.platform()) {
@@ -56,3 +56,110 @@ test(
     ])
   },
 )
+
+test(
+  'includes js APIs for plugins',
+  {
+    fs: {
+      'package.json': json`
+        {
+          "dependencies": {}
+        }
+      `,
+      'index.html': html`
+        <div class="underline example1 example2 example3"></div>
+      `,
+      'src/index.css': css`
+        @import 'tailwindcss/theme' theme(reference);
+        @import 'tailwindcss/utilities';
+        @plugin './plugin.js';
+        @plugin './plugin.cjs';
+        @plugin './plugin.ts';
+      `,
+      'src/plugin.js': js`
+        import plugin from 'tailwindcss/plugin'
+
+        // Make sure all available JS APIs can be imported and used
+        import * as tw from 'tailwindcss'
+        import colors from 'tailwindcss/colors'
+        import flattenColorPalette from 'tailwindcss/lib/util/flattenColorPalette'
+        import defaultTheme from 'tailwindcss/defaultTheme'
+        import * as pkg from 'tailwindcss/package.json'
+
+        export default plugin(function ({ addUtilities }) {
+          addUtilities({
+            '.example1': {
+              '--version': pkg.version,
+              '--default-theme': typeof defaultTheme,
+              '--flatten-color-palette': typeof flattenColorPalette,
+              '--colors': typeof colors,
+              '--core': typeof tw,
+              color: 'red',
+            },
+          })
+        })
+      `,
+      'src/plugin.cjs': js`
+        const plugin = require('tailwindcss/plugin')
+
+        // Make sure all available JS APIs can be imported and used
+        const tw = require('tailwindcss')
+        const colors = require('tailwindcss/colors')
+        const flattenColorPalette = require('tailwindcss/lib/util/flattenColorPalette')
+        const defaultTheme = require('tailwindcss/defaultTheme')
+        const pkg = require('tailwindcss/package.json')
+
+        module.exports = plugin(function ({ addUtilities }) {
+          addUtilities({
+            '.example2': {
+              '--version': pkg.version,
+              '--default-theme': typeof defaultTheme,
+              '--flatten-color-palette': typeof flattenColorPalette,
+              '--colors': typeof colors,
+              '--core': typeof tw,
+              color: 'red',
+            },
+          })
+        })
+      `,
+      'src/plugin.ts': js`
+        import plugin from 'tailwindcss/plugin'
+
+        // Make sure all available JS APIs can be imported and used
+        import * as tw from 'tailwindcss'
+        import colors from 'tailwindcss/colors'
+        import flattenColorPalette from 'tailwindcss/lib/util/flattenColorPalette'
+        import defaultTheme from 'tailwindcss/defaultTheme'
+        import * as pkg from 'tailwindcss/package.json'
+
+        export interface PluginOptions {
+        }
+
+        export default plugin(function ({ addUtilities }) {
+          addUtilities({
+            '.example3': {
+              '--version': pkg.version,
+              '--default-theme': typeof defaultTheme,
+              '--flatten-color-palette': typeof flattenColorPalette,
+              '--colors': typeof colors,
+              '--core': typeof tw,
+              color: 'red',
+            },
+          })
+        })
+      `,
+    },
+  },
+  async ({ fs, exec }) => {
+    await exec(
+      `${path.resolve(__dirname, `../../packages/@tailwindcss-standalone/dist/${STANDALONE_BINARY}`)} --input src/index.css --output dist/out.css`,
+    )
+
+    await fs.expectFileToContain('dist/out.css', [
+      candidate`underline`,
+      candidate`example1`,
+      candidate` example2`,
+      candidate`example3`,
+    ])
+  },
+)

packages/@tailwindcss-standalone/package.json

@@ -42,8 +42,8 @@
     "@parcel/watcher-linux-x64-glibc": "^2.5.1",
     "@parcel/watcher-linux-x64-musl": "^2.5.1",
     "@parcel/watcher-win32-x64": "^2.5.1",
-    "@types/bun": "^1.2.2",
-    "bun": "1.1.43",
+    "@types/bun": "^1.2.3",
+    "bun": "^1.2.3",
     "lightningcss-darwin-arm64": "^1.29.1",
     "lightningcss-darwin-x64": "^1.29.1",
     "lightningcss-linux-arm64-gnu": "^1.29.1",

packages/@tailwindcss-standalone/src/index.ts

@@ -71,4 +71,40 @@ globalThis.__tw_readFile = async (path, encoding) => {
   return fs.readFileSync(path, encoding)
 }
 
+// We use a plugin to make sure that the JS APIs are bundled with the standalone
+// CLI and can be imported inside configs and plugins
+Bun.plugin({
+  name: 'bundle-tailwindcss-apis',
+  target: 'bun',
+  async setup(build) {
+    // These imports must be static strings otherwise they won't be bundled
+    let bundled = {
+      tailwindcss: await import('tailwindcss'),
+      'tailwindcss/colors': await import('tailwindcss/colors'),
+      'tailwindcss/colors.js': await import('tailwindcss/colors'),
+      'tailwindcss/plugin': await import('tailwindcss/plugin'),
+      'tailwindcss/plugin.js': await import('tailwindcss/plugin'),
+      'tailwindcss/package.json': await import('tailwindcss/package.json'),
+      'tailwindcss/lib/util/flattenColorPalette': await import(
+        'tailwindcss/lib/util/flattenColorPalette'
+      ),
+      'tailwindcss/lib/util/flattenColorPalette.js': await import(
+        'tailwindcss/lib/util/flattenColorPalette'
+      ),
+      'tailwindcss/defaultTheme': await import('tailwindcss/defaultTheme'),
+      'tailwindcss/defaultTheme.js': await import('tailwindcss/defaultTheme'),
+    }
+
+    for (let [id, exports] of Object.entries(bundled)) {
+      build.module(id, () => ({
+        loader: 'object',
+        exports: {
+          ...exports,
+          __esModule: true,
+        },
+      }))
+    }
+  },
+})
+
 await import('../../@tailwindcss-cli/src/index.ts')

playgrounds/vite/package.json

@@ -18,7 +18,7 @@
   "devDependencies": {
     "@types/react": "^19.0.10",
     "@types/react-dom": "^19.0.4",
-    "bun": "^1.1.29",
+    "bun": "^1.2.3",
     "vite": "catalog:"
   }
 }