The Listing Tape
One tape, read top to bottom.
No left rail, no inspector pane, no column hunt. Operations stack down a single measure, each with its address in the gutter and its depth in the indent.
tape · deploy/prod-edge · run 4471
0118open deploy --target prod-edgerunning
0119scheduler size cohort to 10%ok
0120gate check error-budget ≤ 0.5%hold
0121edge-1 shift traffic to v4.2ok
0122close deploy --write ledgerok
Why Spool
Inspectable. Reversible. Fast.
Address gutter
Every line is numbered the moment it stamps. Cite a step, link a step, rewind a step — the address never moves.
Scope depth
Operations indent under the scope that ran them. The call tree is the layout — no frames, no rails, no nesting cards.
Reverse-video replay
Pick a line and it flips to paper. Wind the tape back to that address and stamp it again, with the same evidence.
Replay
Wind back to any address.
State is never lost between lines. Land on a stamped address and Spool reconstructs exactly what the operation saw — same cohort, same artifact, same budget — then runs it forward again.
Open the replay head0118open deploy
0119size cohort 10%
0120check error-budget — head here
0121shift traffic v4.2
0122close deploy