Jev front router: 1.2M decisions, only 6 paid calls
The author presents a stack where Jev handles every yes/no, routing and scoring call, waking Opus 5.5 only for low-confidence or prose cases, so 1.2 million decisions in a day led to just 6 paid calls.
JEV + OPUS 5.5 + ONE ROUTER = A STACK THAT NEVER PAYS FOR A DECISION AGAIN the whole idea of jev engineering: the model that decides is not the model that writes, and they were never supposed to be the same bill. jev takes every yes, no, route and score opus 5.5 only wakes when something actually needs a sentence one line decides which call goes where here is what sits inside: - the router (the only thing that sees every call) > http://route.py - one call in, a typed verdict out, no model picked yet > policy.md - what is allowed to reach a paid model, what dies at jev > costs.log - every call priced live, so the meter is never a surprise - the decider · jev > 70ms a call, output billed at zero because it never writes a token > returns a typed value with a confidence score, not a paragraph to parse > 1,204,882 decisions today, 6 escalated, the rest closed right here - the writer · opus 5.5 and gpt-6 astra > only fires when jev flags "this needs prose" or "confidence too low" > the four-figure part of the bill, now touched a few times a day, not every call > same models, same quality, a rounding error of the volume - the ledger > append-only, every verdict timestamped and sourced > a wrong call is never rewritten, a new one lands on top and outvotes it > rebuild the whole index from the log in 8 seconds 1,204,882 decisions in. 6 of them cost real money. here is the part nobody prices out: a decision that never becomes a sentence cannot be wrong and cannot bill output, because there is no output. you were not paying opus for intelligence on those calls, you were paying it to write down an answer it already had. worth stealing even if you never drop opus: put jev in front of it. ninety-nine percent of your calls die before they reach the meter, and the invoice stops being a mystery. the full jev engineering build is in the article below.
This post quotes another post: “A complete guide to getting started building with Jev”