A simple Node.JS (and typescript) library to (de)crypt RPGMaker MV .rpgmvX files (.rpgmvp for images, etc).
Encrypted files start with a 16 byte magic number. Encrypted files only have their first 16 bytes xor encrypted with the 16 byte encryption key. The encryption key can be found in the encryptionKey field of the System.json file of the game.