- Block entity data
- Tags common to all block entities
- blockState: The moving block represented by this block entity.
- extending: 1 or 0 (true/false) – true if the block is being pushed.
- facing: Direction that the piston pushes (0=down, 1=up, 2=north, 3=south, 4=west, 5=east).
- progress: How far the block has been moved.
- source: 1 or 0 (true/false) – true if the block represents the piston head itself, false if it represents a block being pushed.