Mechanics

01 · Clearing algorithm

At the end of each epoch, find a single clearing price P: the largest volume that can match orders willing to buy at ≥ P against orders willing to sell at ≤ P. Every fill prints at that price — whatever your limit, the fill price is the same. That's the single pitch.

// bids sorted high-to-low, asks low-to-high
// find the largest P where willing buy (limit>=P) and sell (limit<=P) can match
export function indicativeClear(bids: Order[], asks: Order[]) {
  const prices = [...new Set([...bids, ...asks].map(o => o.limit))]
    .sort((a, b) => a - b);
  let best = null;
  for (const p of prices) {
    const buy  = bids.filter(o => o.limit >= p).reduce((s, o) => s + o.qty, 0);
    const sell = asks.filter(o => o.limit <= p).reduce((s, o) => s + o.qty, 0);
    const filled = Math.min(buy, sell);
    if (!best || filled > best.filled) best = { price: p, filled };
  }
  return best; // i.e. "the price the book would print if it closed now"
}

Note: on the frontend this calculation only previews the indicative clearing price. On-chain, clearing must run inside the settlement transaction — the frontend result doesn't count.

02 · Why gas can't buy a better price

In an AMM or order book, fill order sets the price — paying more gas to jump the queue gets you an earlier, better price. In CHORUS, every order in an epoch fills at one price; arrival order only affects whether you fill, never the fill price — front-running is pointless.

03 · Current rules (v1 demo)

• epoch length: default 60s, configurable per market (set in the Launch form).
• quote asset: ETH preferred, stablecoins (USDC) second.
• unfilled orders: all cancelled at the end of the round, never rolled into the next — every epoch is a clean chorus.
• factory: the demo starts with an owner switch; ownerless and non-upgradeable means deploy-once-fixed-forever, to be turned on once the rules are frozen.

04 · Risks