diff --git a/file.go b/file.go
index da17764..925ad93 100644
--- a/file.go
+++ b/file.go
@@ -17,6 +17,10 @@ var fileMD string
 
 func init() {
 	obj := map[string]any{
+		"exists": func(argsIn goja.FunctionCall, vm *goja.Runtime) goja.Value {
+			args := gojs.MakeArgs(&argsIn, vm).Check(1)
+			return vm.ToValue(u.FileExists(args.Path(0)))
+		},
 		"read": func(argsIn goja.FunctionCall, vm *goja.Runtime) goja.Value {
 			args := gojs.MakeArgs(&argsIn, vm).Check(1)
 			if r, err := u.ReadFile(args.Path(0)); err == nil {
diff --git a/file.ts b/file.ts
index 0230e98..33acf4a 100644
--- a/file.ts
+++ b/file.ts
@@ -1,6 +1,7 @@
 // just for develop
 
 export default {
+    exists,
     read,
     readBytes,
     write,
@@ -13,16 +14,17 @@ export default {
     cache
 }
 
-function read(filename: string): string {return ''}
-function readBytes(filename: string): any {return null}
-function write(filename: string, data: any): void {}
-function dir(filename: string): Array<FileInfo> {return null as any}
-function stat(filename: string): FileInfo {return null as any}
-function find(filename: string): string {return ''}
-function remove(filename: string): void {}
-function rename(from: string, to: string): void {}
-function copy(from: string, to: string): void {}
-function cache(filename: string, isCompress: boolean): void {}
+function exists(filename: string): boolean { return false }
+function read(filename: string): string { return '' }
+function readBytes(filename: string): any { return null }
+function write(filename: string, data: any): void { }
+function dir(filename: string): Array<FileInfo> { return null as any }
+function stat(filename: string): FileInfo { return null as any }
+function find(filename: string): string { return '' }
+function remove(filename: string): void { }
+function rename(from: string, to: string): void { }
+function copy(from: string, to: string): void { }
+function cache(filename: string, isCompress: boolean): void { }
 
 interface FileInfo {
     name: string
diff --git a/go.mod b/go.mod
index 7ccde64..5bd7117 100644
--- a/go.mod
+++ b/go.mod
@@ -3,7 +3,7 @@ module apigo.cc/gojs/file
 go 1.18
 
 require (
-	apigo.cc/gojs v0.0.1
+	apigo.cc/gojs v0.0.3
 	github.com/ssgo/u v1.7.9
 )