Dark Factory — Pocketful (FJoN)

FJoN built a dark factory on BAND Desktop: three OpenCode agents — coordinator, implementer, and reviewer — collaborating through @mention routing to build Pocketful, a wallet and payments service, entirely from a written specification. The coordinator receives the stage task as the sole human input, then dispatches a self-contained handoff to the implementer. The implementer writes the full service, runs harness checks, commits the work, and hands off to the reviewer. The reviewer independently re-runs the same checks, reads the diff adversarially, and either accepts or returns a structured failure report. The coordinator accepts only reviewer-approved revisions and routes any failures back to the implementer for rework. No human intervenes between dispatch and final report. The factory produced a fully working Pocketful stage 1 service: a containerized HTTP API with user authentication (bcrypt), wallet transfers, payment requests, bill splitting with exact integer arithmetic, operator settlements, idempotent write paths, and full state export/import — passing 100% of the shipped harness checks. Stack: OpenCode v2.0.22 · deepseek-v4-flash · AgentRouter · Python · FastAPI · SQLite (WAL) · Docker Alpine