Unfortunately, Terabey: The Room Builder has no mod support. Given this is the final version of this particular project, it probably won't be added either.
However, we are considering adding it to Terabey: The Home Builder once we have decided to develop it further into an app after we have released the web version.
With enough skill one might be able to directly inject an object into the game, given they understand the rather primitive systems we used during the development of this game. Otherwise you would have to deal with the items/objects at hand.
Though, if you have any suggestions regarding any items/objects you might like to see in the future, we'd love to hear about it!
We hope this clarifies things a little bit!
- Mel (the artist)