Can someone help me figure out a good starting point for coding GNOME extensions?

[ghost]

Hello everyone, I wanted to ask if anyone here knows a good launching resource that will help me code gnome apps so that I can contribute to extensions like this. I've been able to replicate some extensions in the example repositories, but it doesn't seem like the complexity of the apps matches what I see in the extension directories provided in extensions such as these. Any help would be greatly appreciated.