diff --git a/README.md b/README.md
index 8d94d93..017b26e 100644
--- a/README.md
+++ b/README.md
@@ -13,8 +13,8 @@ const on_open = function () {
 	FRAMEROCK_UTILS.transport_send_bytes(new TextEncoder().encode('Hello from client!'))
 	return
 }
-const on_message = function (data) {
-	console.log(['Client received message:', new TextDecoder().decode(data)])
+const on_message = function (event) {
+	console.log(['Client received message:', new TextDecoder().decode(event.data)])
 	return
 }
 FRAMEROCK_UTILS.setup_transport({ on_open, on_message })
@@ -35,4 +35,3 @@ const config = {
 
 async_run({ config, jsbuild_app_frontend, handle_transport_bytes }).then(()=>{}).catch(console.error)
 ```
-
diff --git a/frontend/index.js b/frontend/index.js
index 354482c..368fbdd 100644
--- a/frontend/index.js
+++ b/frontend/index.js
@@ -30,7 +30,7 @@ class FramerockUtils {
 		return
 		
 	}
-	_setup_transport ({ on_open, on_close, on_message }) {
+	_setup_transport ({ on_open, on_close, on_message, on_error }) {
 		
 		console.debug('SETUP TRANSPORT')
 		
@@ -38,9 +38,9 @@ class FramerockUtils {
 		const ws = this._ws
 		ws.binaryType = 'arraybuffer'
 		
-		const func_on_open = () => {
+		const func_on_open = (event) => {
 			console.debug('WS OPEN')
-			on_open && on_open()
+			on_open && on_open(event)
 			return
 		}
 		const func_on_close = (event) => {
@@ -51,15 +51,16 @@ class FramerockUtils {
 		const func_on_message = (event) => {
 			console.debug('WS MESSAGE', event)
 			if (on_message !== undefined) {
-				on_message(event.data)
+				on_message(event)
 			}
 			else {
 				console.warn(['Unhandled message', event])
 			}
 			return
 		}
-		const func_on_error = () => {
+		const func_on_error = (event) => {
 			console.debug('WS ERROR')
+			on_error && on_error(event)
 			return
 		}