diff --git a/packages/page-agent/package.json b/packages/page-agent/package.json
index 88f8fd7..538f510 100644
--- a/packages/page-agent/package.json
+++ b/packages/page-agent/package.json
@@ -37,9 +37,9 @@
 	},
 	"homepage": "https://alibaba.github.io/page-agent/",
 	"scripts": {
-		"build": "vite build && MODE=umd vite build",
+		"build": "vite build && vite build --config vite.umd.config.js",
 		"serve": "npx serve dist/umd -p 5173",
-		"dev:umd": "concurrently \"MODE=umd vite build --watch\" \"npm run serve\"",
+		"dev:umd": "concurrently \"vite build --config vite.umd.config.js --watch\" \"npm run serve\"",
 		"prepublishOnly": "node -e \"const fs=require('fs');['README.md','LICENSE'].forEach(f=>fs.copyFileSync('../../'+f,f))\"",
 		"postpublish": "node -e \"['README.md','LICENSE'].forEach(f=>{try{require('fs').unlinkSync(f)}catch{}})\""
 	},
diff --git a/packages/page-agent/vite.config.js b/packages/page-agent/vite.config.js
index f5d4f37..bc210ec 100644
--- a/packages/page-agent/vite.config.js
+++ b/packages/page-agent/vite.config.js
@@ -1,7 +1,4 @@
 // @ts-check
-import chalk from 'chalk'
-import 'dotenv/config'
-import process from 'node:process'
 import { dirname, resolve } from 'path'
 import dts from 'unplugin-dts/vite'
 import { fileURLToPath } from 'url'
@@ -10,11 +7,8 @@ import cssInjectedByJsPlugin from 'vite-plugin-css-injected-by-js'
 
 const __dirname = dirname(fileURLToPath(import.meta.url))
 
-// ============================================================================
 // ES Module for NPM Package
-// ============================================================================
-/** @type {import('vite').UserConfig} */
-const esmConfig = {
+export default defineConfig({
 	clearScreen: false,
 	plugins: [
 		dts({ tsconfigPath: './tsconfig.dts.json', bundleTypes: true }),
@@ -47,58 +41,4 @@ const esmConfig = {
 	define: {
 		'process.env.NODE_ENV': '"production"',
 	},
-}
-
-// ============================================================================
-// UMD Bundle for CDN
-// - alias all local packages so that they can be build in
-// - no external
-// - no d.ts. dts does not work with monorepo aliasing
-// ============================================================================
-/** @type {import('vite').UserConfig} */
-const umdConfig = {
-	plugins: [cssInjectedByJsPlugin({ relativeCSSInjection: true })],
-	publicDir: false,
-	esbuild: {
-		keepNames: true,
-	},
-	resolve: {
-		alias: {
-			'@page-agent/page-controller': resolve(__dirname, '../page-controller/src/PageController.ts'),
-			'@page-agent/ui': resolve(__dirname, '../ui/src/index.ts'),
-		},
-	},
-	build: {
-		lib: {
-			entry: resolve(__dirname, 'src/umd.ts'),
-			name: 'PageAgent',
-			fileName: 'page-agent',
-			formats: ['umd'],
-		},
-		outDir: resolve(__dirname, 'dist', 'umd'),
-		rollupOptions: {
-			output: {
-				entryFileNames: 'page-agent.js', // 强制指定完整文件名
-			},
-		},
-		cssCodeSplit: true,
-	},
-	define: {
-		'process.env.NODE_ENV': '"production"',
-	},
-}
-
-// ============================================================================
-
-const MODE = process.env.MODE
-
-console.log(chalk.cyan(`📦 Build mode: ${chalk.bold(MODE || 'esm')}`))
-
-let config
-if (MODE === 'umd') {
-	config = umdConfig
-} else {
-	config = esmConfig
-}
-
-export default defineConfig(config)
+})
diff --git a/packages/page-agent/vite.umd.config.js b/packages/page-agent/vite.umd.config.js
new file mode 100644
index 0000000..fc89b61
--- /dev/null
+++ b/packages/page-agent/vite.umd.config.js
@@ -0,0 +1,44 @@
+// @ts-check
+import { dirname, resolve } from 'path'
+import { fileURLToPath } from 'url'
+import { defineConfig } from 'vite'
+import cssInjectedByJsPlugin from 'vite-plugin-css-injected-by-js'
+
+const __dirname = dirname(fileURLToPath(import.meta.url))
+
+// UMD Bundle for CDN
+// - alias all local packages so that they can be build in
+// - no external
+// - no d.ts. dts does not work with monorepo aliasing
+export default defineConfig({
+	plugins: [cssInjectedByJsPlugin({ relativeCSSInjection: true })],
+	publicDir: false,
+	esbuild: {
+		keepNames: true,
+	},
+	resolve: {
+		alias: {
+			'@page-agent/page-controller': resolve(__dirname, '../page-controller/src/PageController.ts'),
+			'@page-agent/ui': resolve(__dirname, '../ui/src/index.ts'),
+		},
+	},
+	build: {
+		lib: {
+			entry: resolve(__dirname, 'src/umd.ts'),
+			name: 'PageAgent',
+			fileName: 'page-agent',
+			formats: ['umd'],
+		},
+		outDir: resolve(__dirname, 'dist', 'umd'),
+		rollupOptions: {
+			output: {
+				// force use .js as extension
+				entryFileNames: 'page-agent.js',
+			},
+		},
+		cssCodeSplit: true,
+	},
+	define: {
+		'process.env.NODE_ENV': '"production"',
+	},
+})