diff --git a/src/etc/example-char.js b/src/etc/example-char.js
index 3d6cc3e8..a73971fb 100644
--- a/src/etc/example-char.js
+++ b/src/etc/example-char.js
@@ -5,7 +5,7 @@
 //@use editProcess
 //@use editDisplay
 //@use onButtonClick
-
+//@use modifyRequestChat
 
 
 async function editInput(text){
@@ -45,6 +45,14 @@ async function onButtonClick(code){
     return
 }
 
+async function modifyRequestChat(chat){
+    //modifyRequestChat is a callable function that is called when before request.
+    //the first argument is the chat array. chat array is almost same as OpenAI's chat array.
+    //unlike editProcess, its called after other fixes is done, and its only called once, with the whole chat array.
+    //the chat array would replaced to return value and used in request.
+    return chat
+}
+
 
 async function showcase(){
     //this is a function for just introducing the apis.