Computing a commitment

The commitment is plain abi.encode then keccak256. Compute it off-chain; commitmentOf exists to check your code against the contract.

TypeScript, with viem

import { encodeAbiParameters, keccak256, toHex } from "viem";

const salt = toHex(crypto.getRandomValues(new Uint8Array(32)));

const commitment = keccak256(
  encodeAbiParameters(
    [
      { type: "address" }, { type: "uint256" }, { type: "uint256" },
      { type: "uint8" }, { type: "uint256" }, { type: "uint256" }, { type: "bytes32" },
    ],
    [trader, batch, market, side, amount, limitPx, salt],
  ),
);

Units

• amount for a buy is USDG in raw units (6 decimals) and includes the fee budget. For a sell it is shares in raw units (18 decimals).
• limitPx is USDG raw per 1e18 share raw. A limit of $226.10 per share is 226100000.

Which batch

Read currentBatch() and commit while the phase is 0. If the phase flips to reveal before your transaction lands, commit reverts with WrongPhase and nothing is lost but gas. Commit early in the window.