jib

works owns machines and the bell; marrow's servants never touch a mechanism. a jib is neither: a steel post with a two-joint arm that does the one job works cannot do for itself — the hand at the machine. it carries a stack between containers, it presses a lever or a button, it pumps a works treadle, and it learns all three the same way: use it empty-handed, use the source, use the target. no menu, no filter list, no recipe of its own.

the arm is not a blockbench file — it is built from cubes in code, shoulder to gripper, so its swing can be driven by joint angles instead of baked frames. taught, it turns to face whichever end of the lesson it is reaching for and lerps through rest, reach-source, reach-target; untaught, it sways slow and idle with the gripper open, sparking at whichever end is already set. that swing, waiting on nothing but the ring beneath it, is the whole dopamine.

a jib runs only while its post touches ringing amethyst, drawing load the same as any thrum consumer, and its swing period is set by the ring's own speed — a strained ring slows every arm on it together, which is the sound of a line running too hot. with no thrum aboard the arm never moves at all, and it says so plainly rather than pretending.

there is no recipe machine here and no item printer: a jib only ever moves what a hopper could move or presses what a hand could press. mass production is a line you built, taught by hand, arm by arm, and watched running — never a block with a list.