Nightwatch Foundry: a four-seat dark factory

Nightwatch Foundry is a dark factory built on BAND Desktop: four Codex seats share one room and turn a single human dispatch into working software, stage by stage, with no steering afterwards. The Foundry Coordinator plans each stage, splits ownership and sends the complete specification to the other seats as numbered handoff parts that must be acknowledged before work starts. The Systems Engineer owns integrity-critical behaviour: state, concurrency, idempotency and recovery. The Interface Engineer owns the HTTP surface, the browser product and presentation quality. The Independent Verifier works from a fresh clone, runs the official isolated harness and its own specification-derived probes, and may reject promotion; a stage is accepted only against an exact commit. In the scored run the factory completed all four tablekeeper stages in 10 h 39 min from one dispatch. The shipped checks pass on a fresh clone: 120/120, 25/25, 7/7 and 6/6. Review was real: the verifier rejected candidates six times and withdrew its own acceptance twice while the official checks were already passing, and every time a builder changed the code. The band made 381 commits across all four seats and used about 662 million tokens. The four mandates are generic: they describe ownership, handoffs, evidence and rejection rules and name no endpoint, field or error code. FACTORY.md documents setup, design choices and their cost, what failed (Stage 1 took five hours because nothing ranked the verifier's findings) and the revised mandates we would run next. The repository holds the mandates, the unedited room export, one buildable folder per stage and the band's evidence.