diff --git a/next/assets/assets.go b/next/assets/assets.go
index 4f048d4..0d48269 100644
--- a/next/assets/assets.go
+++ b/next/assets/assets.go
@@ -1,90 +1,29 @@
 package assets
 
-import (
-	"XProxy/next/logger"
-	"os"
-	"time"
-)
-
-// saveAsset is used to write to a local file and specify its last modify
-// time. If the file exists, it will be replaced.
-func saveAsset(file string, content []byte, date *time.Time) error {
-	fp, err := os.OpenFile(file, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
-	if err != nil {
-		logger.Errorf("Failed to open file `%s` -> %v", file, err)
-		return err
-	}
-	defer fp.Close()
-
-	_, err = fp.Write(content)
-	if err != nil {
-		logger.Errorf("Failed to save file `%s` -> %v", file, err)
-		return err
-	}
-
-	if date != nil { // change local file last modify time
-		if err := os.Chtimes(file, *date, *date); err != nil {
-			logger.Warnf("Failed to change asset modification time")
-		} else {
-			logger.Debugf("Change `%s` modification time to `%v`", file, date)
-		}
-	}
-	return nil
+var buildinAssets = map[string]string{
+	"geoip.dat":   "geoip.dat.xz",
+	"geosite.dat": "geosite.dat.xz",
 }
 
-// updateRemoteAsset will download remote asset via the optional proxy and
-// save them locally. Local files will be overwritten if they exist.
-func updateRemoteAsset(file string, url string, proxy string) error {
-	logger.Debugf("Start downloading remote asset `%s` to `%s`", url, file)
-	asset, date, err := downloadAsset(url, proxy)
-	if err != nil {
-		logger.Errorf("Failed to download remote asset `%s`", url)
-		return err
-	}
-	if asset, err = tryExtract(asset); err != nil {
-		return err
-	}
-	if err := saveAsset(file, asset, date); err != nil {
-		return err
-	}
-	logger.Infof("Successfully obtained remote asset `%s`", file)
-	return nil
-}
+func Demo() {
 
-// updateLocalAsset will extract local asset and save them locally. If the
-// local file already exists, it will be skipped.
-func updateLocalAsset(file string, src string) error {
-	_, err := os.Stat(file)
-	if err == nil {
-		logger.Debugf("Local asset `%s` already exist", file)
-		return nil // skip local asset extract
+	remoteAssets := map[string]string{
+		"geoip.dat":   "https://cdn.dnomd343.top/v2ray-rules-dat/geoip.dat.xz",
+		"geosite.dat": "https://cdn.dnomd343.top/v2ray-rules-dat/geosite.dat.xz",
 	}
 
-	var date = time.Now()
-	if stat, err := os.Stat(src); err == nil {
-		date = stat.ModTime() // using last modify time of src file
-	}
+	//updateLocalAssets(buildinAssets, true)
+	//updateLocalAssets(buildinAssets, false)
 
-	logger.Debugf("Start extracting local asset `%s`", file)
-	asset, err := os.ReadFile(src)
-	if err != nil {
-		logger.Errorf("Failed to read local asset -> %v", err)
-		return err
-	}
-	if asset, err = tryExtract(asset); err != nil {
-		return err
-	}
-	if err := saveAsset(file, asset, &date); err != nil {
-		return err
-	}
-	logger.Infof("Successfully extracted local asset `%s`", file)
-	return nil
-}
+	updateRemoteAssets(remoteAssets, "", true)
+	//updateRemoteAssets(remoteAssets, "", false)
+	//updateRemoteAssets(remoteAssets, "socks5://192.168.2.2:1084", true)
+	//updateRemoteAssets(remoteAssets, "socks5://192.168.2.2:1084", false)
 
-func Demo() {
+	//time.Sleep(10 * time.Second)
 
 	//updateRemoteAsset("geosite.dat", "http://cdn.dnomd343.top/v2ray-rules-dat/geosite.dat.xz", "")
 	//updateRemoteAsset("geosite.dat", "http://cdn.dnomd343.top/v2ray-rules-dat/geosite.dat.xz", "socks5://192.168.2.2:1084")
-	updateLocalAsset("geosite.dat", "geosite.dat.xz")
+	//updateLocalAsset("geosite.dat", "geosite.dat.xz")
 
 }
diff --git a/next/assets/update.go b/next/assets/update.go
new file mode 100644
index 0000000..f8dc4c3
--- /dev/null
+++ b/next/assets/update.go
@@ -0,0 +1,128 @@
+package assets
+
+import (
+	"XProxy/next/logger"
+	"os"
+	"sync"
+	"time"
+)
+
+// saveAsset is used to write to a local file and specify its last modify
+// time. If the file exists, it will be replaced.
+func saveAsset(file string, content []byte, date *time.Time) error {
+	// TODO: create folder if not exist
+	fp, err := os.OpenFile(file, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
+	if err != nil {
+		logger.Errorf("Failed to open file `%s` -> %v", file, err)
+		return err
+	}
+	defer fp.Close()
+
+	_, err = fp.Write(content)
+	if err != nil {
+		logger.Errorf("Failed to save file `%s` -> %v", file, err)
+		return err
+	}
+
+	if date != nil { // change local file last modify time
+		if err := os.Chtimes(file, *date, *date); err != nil {
+			logger.Warnf("Failed to change asset modification time")
+		} else {
+			logger.Debugf("Change `%s` modification time to `%v`", file, date)
+		}
+	}
+	return nil
+}
+
+// updateRemoteAsset will download remote asset via the optional proxy and
+// save them locally. Local files will be overwritten if they exist.
+func updateRemoteAsset(file string, url string, proxy string) error {
+	logger.Debugf("Start downloading remote asset `%s` to `%s`", url, file)
+	asset, date, err := downloadAsset(url, proxy)
+	if err != nil {
+		logger.Errorf("Failed to download remote asset `%s`", url)
+		return err
+	}
+	if asset, err = tryExtract(asset); err != nil {
+		return err
+	}
+	if err := saveAsset(file, asset, date); err != nil {
+		return err
+	}
+	logger.Infof("Successfully obtained remote asset `%s`", file)
+	return nil
+}
+
+// updateLocalAsset will extract local asset and save them locally. If the
+// local file already exists, it will be skipped.
+func updateLocalAsset(file string, src string) error {
+	_, err := os.Stat(file)
+	if err == nil {
+		logger.Debugf("Local asset `%s` already exist", file)
+		return nil // skip local asset extract
+	}
+
+	var date = time.Now()
+	if stat, err := os.Stat(src); err == nil {
+		date = stat.ModTime() // using last modify time of src file
+	}
+
+	logger.Debugf("Start extracting local asset `%s`", file)
+	asset, err := os.ReadFile(src)
+	if err != nil {
+		logger.Errorf("Failed to read local asset -> %v", err)
+		return err
+	}
+	if asset, err = tryExtract(asset); err != nil {
+		return err
+	}
+	if err := saveAsset(file, asset, &date); err != nil {
+		return err
+	}
+	logger.Infof("Successfully extracted local asset `%s`", file)
+	return nil
+}
+
+// updateMultiple performs multiple update tasks, optionally in parallel.
+func updateMultiple(updates []func(), parallel bool) {
+	if !parallel {
+		for _, update := range updates {
+			update() // sequential update
+		}
+		return
+	}
+	var wg sync.WaitGroup
+	for _, update := range updates {
+		update_ := update
+		wg.Add(1)
+		go func() { // parallel update
+			update_()
+			wg.Done()
+		}()
+	}
+	wg.Wait() // wait all update tasks done
+}
+
+// updateRemoteAssets will update multiple remote assets in batches.
+func updateRemoteAssets(assets map[string]string, proxy string, parallel bool) {
+	var tasks []func()
+	for file, url := range assets {
+		file_, url_ := file, url
+		tasks = append(tasks, func() {
+			_ = updateRemoteAsset(file_, url_, proxy)
+		})
+	}
+	updateMultiple(tasks, parallel)
+}
+
+// updateLocalAssets will extract multiple local assets in batches.
+func updateLocalAssets(assets map[string]string, parallel bool) {
+	var tasks []func()
+	for file, src := range assets {
+		file_, src_ := file, src
+		tasks = append(tasks, func() {
+			_ = updateLocalAsset(file_, src_)
+		})
+	}
+	updateMultiple(tasks, parallel)
+}