Four agents build the Jev system: pinning model versions for a $100K/month product
Four agents on Haiku, Sonnet and Opus split the work with Jev making final decisions, and a ROOT.md file pins each model version to prevent drift across 334 paying customers.
ANTHROPIC'S 4 AGENTS BUILD THE JEV SYSTEM IN 60 MINUTES, DOING $100K A MONTH. ONE WORD IN THE CONFIG WOULD QUIETLY BREAK ALL OF IT. The word is "latest". Point an agent at it and the model underneath updates on its own schedule. No error, no warning, no failed request. The answers just start drifting away from the ones you tested, and nothing in the logs says why. This setup never lets that happen. Every agent is pinned to one exact version, written down in a file called ROOT.md: > SCOUT on Haiku 4.5 reads the market > BUILDER on Sonnet 5 writes everything > CRITIC on Opus 5 decides what ships > OPERATOR on Haiku through the batch API, half price, the one seat that never has to hurry Then Jev sits at the end of the chain. The split is not random. BUILDER takes 59% of the hour because it is the only agent that writes, and writing costs 5x more than reading. Everyone else is built to answer short, and short answers are cheap answers. The economics of the whole system rests on that. The result is a product that bills $100K a month, 334 customers at $299, and behaves next month exactly the way it behaves today. Four versions, one file, no drift. Pin them and Jev stays Jev. Save this and paste it into Claude Code before you let any agent run on "latest".