diff --git a/scripts/buildExternal.js b/scripts/buildExternal.js
index 0dd2d4c..b92cfb0 100644
--- a/scripts/buildExternal.js
+++ b/scripts/buildExternal.js
@@ -1,7 +1,10 @@
 import { execSync } from 'child_process'
 import { join } from 'path'
 import { fileURLToPath } from 'url'
-import { unlink } from 'fs/promises'
+import { rename, unlink } from 'fs/promises'
+import { glob } from 'glob'
+
+console.log('[buildExternal] building with node', process.version)
 
 // Get the project root directory
 const __dirname = fileURLToPath(new URL('.', import.meta.url))
@@ -10,7 +13,7 @@ const projectRoot = join(__dirname, '..')
 async function buildExternal() {
     try {
         // Compile TypeScript using local tsc
-        console.log('Compiling TypeScript...')
+        console.log('[buildExternal] Compiling TypeScript...')
         execSync(
             'npx tsc main.ts --target es2020 --module esnext --moduleResolution bundler --listEmittedFiles',
             {
@@ -20,7 +23,7 @@ async function buildExternal() {
         )
 
         // Bundle with esbuild
-        console.log('Bundling with esbuild...')
+        console.log('[buildExternal] Bundling with esbuild...')
         execSync(
             'npx esbuild main.js --bundle --format=esm --target=esnext --outfile=out.js --minify --legal-comments=none',
             {
@@ -29,35 +32,30 @@ async function buildExternal() {
             }
         )
 
-        // Move output file to public directory
-        console.log('Moving output file to public directory...')
-        execSync('mv ./out.js ./public/out.js', {
-            stdio: 'inherit',
-            cwd: projectRoot,
-        })
+        // Move output file to public directory - cross platform
+        console.log('[buildExternal] Moving output file to public directory...')
+        await rename(join(projectRoot, 'out.js'), join(projectRoot, 'public', 'out.js'))
 
-        // Clean up temporary files
-        console.log('Cleaning up...')
+        // Clean up temporary files - cross platform
+        console.log('[buildExternal] Cleaning up...')
         await Promise.all([
-            // Remove lib/*.js files
-            execSync('rm -rf ./lib/**/**.js && rm -rf ./lib/**.js', {
-                stdio: 'inherit',
-                cwd: projectRoot,
-            }),
+            // Remove lib/*.js files - preserve .ts files
+            (async () => {
+                const jsFiles = await glob('**/*.js', {
+                    cwd: join(projectRoot, 'lib'),
+                    absolute: true,
+                })
+                await Promise.all(jsFiles.map((file) => unlink(file).catch(() => {})))
+            })(),
             // Remove main.js
             unlink(join(projectRoot, 'main.js')).catch(() => {}), // Ignore if file doesn't exist
         ])
 
-        console.log('Build completed successfully!')
+        console.log('[buildExternal] Build completed successfully!')
     } catch (error) {
-        console.error('Build failed:', error)
+        console.error('[buildExternal] Build failed:', error)
         process.exit(1)
     }
 }
 
-// If script is run directly (not imported)
-if (import.meta.url === `file://${process.argv[1]}`) {
-    buildExternal()
-}
-
-export default buildExternal
+buildExternal()