Does anyone know how secret seeds work and if there is a way to mod in custom ones?

[SunsetRex]

The unique world generation of secret seeds really interests me and I was wondering if modders have figured out how it works in code and if/how to create custom ones

 

[Karyopl]

I want to do this too. If you find out, please tell me.

 

[This is Many]

of course you can. just check if seed is what you want and then insert your gen pass(es) or modify vanilla ones (presented in example mod)