Everything you need to see is in the corresponding version .zip file
Free to use code as long as you don't steal everything
Note: I don't always upload my source code. I only do that when I experience critical situations like my PC failing (saying this as of 1.6.1-3 for 1.20.1, 1.21 and 1.21.5 respectively) If I ever halt mod development, the first reason is obvious (PC ded or storage is full). Likewise, just me being busy with life like usual.