Four Seats Factory — Evidence Before Acceptance

The factory. Four seats in one BAND room. An analyst turns the specification into numbered obligations before any code exists. An implementer builds. An adversary attacks the plan, then the code, from its own clean clone. An auditor reproduces everything in fresh containers and is the only seat that can accept. No seat accepts its own work. The mandates never name the product: point the factory at a new problem by changing the dispatch (RUNBOOK.md). What it did. One human message authorised all four stages; nobody typed anything after it. The analyst opened each next stage by itself, and the run ended 4 h 14 min later. Every stage folder claims its own stage on the public harness in isolated mode, and all 21 product commits are the implementer's. Why it matters. Two candidates were rejected, with three findings. A stage-3 candidate passed every public check (147 + 35 + 6 isolated, 150/150 regression, 14/14 migrations) and was rejected anyway: the auditor and the adversary, independently, crashed it out of heap memory, after 4,761 reads in the auditor's run, losing all state. After the repair, 20,000 reads ran at 39.7 MiB. What it built. Pocketful, a wallet service: payments, requests, bill splits, holds, historical statements, immutable corrections and refunds, with a browser UI tested at 375 and 1280 px. One Node.js process, no dependencies. Try it. Live demo: https://four-seats-factory.onrender.com/login ([email protected], password correct horse). setup/verify-from-clone.sh reruns the organisers' harness on a fresh clone. Limits. Public checks only, not the hidden evaluation. About $136 in estimated model spend. The kit was prepared with ChatGPT, the docs written with Claude Code and audited with GPT-6 Sol; the run is the band's alone. The video voice is synthetic. FACTORY.md and EVIDENCE-INDEX.md back every claim.