A game mod is unusual to see as an entry.

My intended use is much simpler.
When you're writing an engine, most opening books are in the Polyglot format (.bin). The positions in the book are encoded with Zobrist hashing (https://www.chessprogramming.org/Zobrist_Hashing). So to check if the position is present in the book, you first need to hash it. And because Murphy's law states that "it's bug-ridden and broken from the start", you need to debug your hashing somehow, ideally comparing with some other generator.
I couldn't find anything to debug my hashing while writing Mussaurus (http://www.talkchess.com/forum3/viewtopic.php?f=2&t=72372), so I wrote my own generator.

https://shinkarom.github.io/zobrist/
When writing a chess engine, you might want to support opening books in Polyglot bin format. This format creates the hash for the position using Zobrist hashing. If you want to debug your hash generator, I haven't found any services that can generate hash from the position.
So I wrote one. You paste the position as FEN and get the resulting hash.