Jev Duel

Jev Duel matchmaking

Jev Duel shows a live Reversi board: Jev (TypeSafe's System One model) plays both sides, one move each turn, and a third Jev referees every move. The agent stages battle.json — the two rivals' personalities, the referee's focus, the show.

The loop

1. Update battle.json (two rivals with clashing personalities). The viewer watches it and reframes both Jevs live — no restart, no second server.
2. node "$JEV_DSH/toolchain/check.mjs" verifies the workspace's battle.json is valid and reports the verdict. Run it before you call a duel done.
3. Watch the board. Do the personalities actually fight? Greed grabs center flips; patience takes corners. If their play looks identical, sharpen the personalities.

Reading Jev

The viewer shows each side "thinking" (blinking), the move it makes, and the referee's per-move call (strong · aggressive/quiet · decided). The drama is the contrast: two distinct Jevs on one board. A corner-taker and a flip-grabber will visibly differ; two identical prompts will not.

Verifying a duel

node "$JEV_DSH/toolchain/check.mjs" returns non-zero when battle.json is invalid (bad size, missing rivals). It doesn't replace watching the game: confirm the board fills, turns alternate, and a winner or draw eventually appears.

Driving Jev yourself

toolchain/jev.mjs exports a small client. Example (from the workspace) — audition personalities with the referee before you stage the duel:

node --input-type=module -e '
import { evaluate, jev } from "$JEV_DSH/toolchain/jev.mjs";
const res = await evaluate({
  state: "A greedy Reversi player who grabs center flips vs a patient corner-taker.",
  questions: {
    clash: jev.score({0:"boring",1:"fun",2:"electric"}, "How much would these two personalities clash on a board?"),
    fair: jev.noul("Is this a fair, winnable matchup for either side?"),
  },
});
console.log(JSON.stringify(res.answers, null, 2));
'

Without TYPESAFE_API_KEY this uses the deterministic mock; set the key to hit live Jev.