Quick Guide to Modding:

You can export material and reaction json files using the in-game console commands:

• export_indiv_materials
• export_indiv_reactions

These will export the json files to the userdata/Materials and userdata/Reactions directories

Userdata directory is C:\Users[username]\AppData\Roaming\godot\app_userdata\Atomcraft

With the latest build (11-27-2025) the game will automatically load any new files you make in those directories on startup, so you can copy from existing files, make some modifications, and then try your materials and reactions in-game!

You can also hot-reload materials & reactions from the user directories after making changes by pressing F3, although if you are changing a lot of things at once or repeatedly overwriting things it might not work and you may need to restart the game at that point. A good way to test this works is to try changing the color of a material in a json file and then press F3 in game to see it update.

Remember you can give yourself your new materials from the console with give command

alrighty look forward to seeing what you come up with!