WorldEdit

The WorldEdit editor as a native mod for Horizon: select a region and fill, replace, shape, copy and paste it with // commands, and load or save schematics. It writes blocks through the game's own code, with no command length limit, in single player and on a LAN world you host or join.

• Select: //wand gives a wooden axe; left click and right click set position 1 and 2 (or //pos1, //pos2).
• Edit: //set, //replace, //walls, //outline, //hollow, //overlay, //sphere, //cyl, //pyramid, //line, //copy, //cut, //paste, //move, //expand, //contract, //shift, //count.
• Patterns: one block or a weighted mix, such as //set 70%stone,30%gravel.
• Undo: //undo and //redo, for the last 10 edits.
• Schematics: //schem load <name> reads a .schem (Sponge v1 to v3), .litematic or .schematic from the world's schematics/ folder, //paste places it, //schem save writes the selection; //schem alone opens a file menu.

//we lists the commands, and // completes in chat. One edit touches at most 250,000 blocks and never loads a chunk; editing needs permission level 2.