diff --git a/docs/developer.md b/docs/developer.md
index 520caa7e7..ab35815fe 100644
--- a/docs/developer.md
+++ b/docs/developer.md
@@ -4,7 +4,7 @@
 
 **Frontend**  
 
-- ui: react-bootstrap, mui, classnames
+- ui: [react-bootstrap](https://react-bootstrap.github.io/), [mui](https://v4.mui.com)
 - js framework: [Create React App](https://create-react-app.dev/docs/documentation-intro)
 - template: no use
 
@@ -13,6 +13,11 @@
 - apphub: this is for application deployment and storage application master data
 - cockpit: this is for running command at host machine
 
+related classes:
+
+- src/helpers/api/apiCore.js (connect cockpit)
+- src/helpers/api/appHub.js
+
 
 ## Build and Test