In-Game Object placement

I was wondering how to go about placing objects in the world via In-Game controls, but have them actually add in the world permanently. I was wondering if there was a way to play the game and build the world in game instead of in the editor.

You would have to construct a system like that yourself.

Still editor based, but the ideas behind it might be of interest

Yea I expected to build my own system for it, I was just wondering if I could do it in blueprints or If I’d have to literally build an editor for it that would be used as a plugin for UE4?

You could possibly do it with blueprints but you might consider doing it with C++ if you can since things with blueprints can get messy if you have to do a lot.