Easily Tie Custom Scripts/Steps Into the Build System

I want to try to generate some files at build time, and I can’t for the life of me find a good place to do that that will work consistently across build machines and developer machines. I’m trying to store the files in an intermediate directory, and they’re required at build time, so making sure they exist before kicking off the build of the project is super important.

The most obvious place I could find where something could be added is the YourProjectName.Build.cs files, because you should be able to add some sort of script dependency instead of a module dependency to it, but as far as I can tell nothing like that exists. It seems like it should be really easy to fire off a separate C# script or even batch file as a dependency to your project, but I just can’t find an easy way to do that that would work well across different build environments.

Would it be easy to add such a system, or does such a system exist somewhere that I can tie into?