How to develop theme what tool i should use？

[DavidDarnes]

Casper theme add other fuction

Hey! I’m not sure what you mean by “tool”, however Casper is a good theme to start with to help you get familiar how Ghost theming works. Use a code editor like VS Code and open up the downloaded theme files, in there you’ll find comments on how some of the theme works and good example code to reference. There’s also our official docs to guide you: