George Stoien@gcs_southbay

Pocketful tests whether a reusable team of coding agents can build and verify a payments service through BAND. An Architect coordinates a Builder, an independent Verifier and a Spec Auditor, using generic seat mandates for ownership, handoffs and review. The result is four independently buildable Docker services. Stage 1: payments and settlements. Stage 2: a browser wallet with payment authorizations, held funds, expiry and captures. Stage 3: statements, historical balances (as_of, known_at), frozen pagination snapshots and idempotent payment corrections with historical overdraft checks. Stage 4: receiver refunds and atomic operator batch corrections across settlements. Each stage keeps earlier code unchanged in its own folder and Git history. Fresh-clone isolated harness runs passed all 147 Stage 1, 35 Stage 2, 6 Stage 3 and 5 Stage 4 checks, with earlier stages re-passing cumulatively. Both independent reviewers approved each stage's exact revision; for Stage 3 they first found three issues, which the Builder fixed. We include source, mandates, the factory description and the unchanged full BAND export. This was a supervised practice run with human execution approvals, host debugging and UI checks, not a fully autonomous judged run. No paid fallback was used, and we did not measure per-seat cost. When the Codex seats hit their usage limit before Stage 4, the owner approved substituting Claude Builder and Verifier seats (disclosed); both reviewers approved Stage 4 at 203e448.

🌎 Online Hackathon | 💻 Online Build: Sept 26 - Oct 5, 2026 A virtual, global hackathon. Build from anywhere in the world. Dark Factory is the official hackathon of WeAreDevelopers World Congress North America, presented by BAND, but you don't need to be in San Jose to take part. For one week, you build a software factory in BAND Desktop: a band of coding agents that plans work, implements it and checks its own results. 🎟️ Bonus for sign-ups: you are eligible for a free ticket to WeAreDevelopers World Congress North America in San Jose (Sep 23–25). If you do go, stop by the BAND booth: a surprise is waiting for you.