I recently added some debug 'spells' you can use by hitting tab and the number keys 1-7 above your alphabet keys on the keyboard. An NPC named Angrito tells you how to use them.
You may be asking about the mod that CEO of Chair is working on though. For that you'd have to visit the discord server's Mods and Programming channel and ask him nicely for the latest version, as I don't think he's hosting it anywhere.