{"description": "A 70 x 50 x 30 box, its vertical edges rounded R6, shelled 2 mm open on top.",
 "commands": [
  {"command": "parameters.change", "params": {"name": "height", "expression": "30 mm"}},
  {"command": "parameters.change", "params": {"name": "wall", "expression": "2 mm"}},
  {"command": "sketch.create", "params": {"plane": "XY", "name": "Outline"}},
  {"command": "sketch.rectangle.center", "params": {"center": [0, 0], "corner": [35, 25]}},
  {"command": "sketch.finish", "params": {}},
  {"command": "solid.extrude", "params": {"distance": "height"}},
  {"command": "solid.fillet", "params": {"edges": [[35, 25, 15], [-35, 25, 15], [35, -25, 15], [-35, -25, 15]], "radius": 6}},
  {"command": "solid.shell", "params": {"faces": [[0, 0, 30]], "thickness": "wall"}}
 ]}