Intent-Based Trading System

Intent states

State	Description
PENDING	Initial state when PartyA creates the intent
LOCKED	Intent reserved by a PartyB
FILLED	Intent executed and trade created
EXPIRED	Intent passed its expiration time
CANCELLED	Intent cancelled by PartyA before filling
CANCEL_PENDING	PartyA cancelled a locked intent, awaiting PartyB confirmation

Trading lifecycle

Step 1: send open intent

PartyA opens an intent by calling:

function sendOpenIntent(
address[] calldata partyBsWhiteList,
uint256 symbolId,
uint256 price,
uint256 quantity,
uint256 strikePrice,
uint256 expirationTimestamp,
uint256 mm,
TradeSide tradeSide,
MarginType marginType,
ExerciseFee memory exerciseFee,
uint256 deadline,
address feeToken,
address affiliate,
bytes memory userData
) external returns (uint256 intentId)

PartyA pays three fees: the protocol fee, the affiliate fee, and the solver fee. Funds are locked depending on the side:

• Buy options: PartyA locks the option premium, premium = option_price × quantity. The premium transfers to PartyB when the trade settles.

• Sell options: PartyA locks the required maintenance margin.

The intent is stored with PENDING status and becomes visible to eligible PartyB accounts.

Step 2: lock open intent

A PartyB can lock the intent when:

• The intent is PENDING and hasn't expired.

• PartyB's address is in partyBsWhiteList.

• PartyB has enough balance to meet its obligations.

• PartyB accepts the terms.

function lockOpenIntent(uint256 intentId) external onlyPartyB

The intent moves from PENDING to LOCKED and is reserved for the locking PartyB.

Step 3: fill open intent

function fillOpenIntent(uint256 intentId, uint256 quantity, uint256 price) external

• Buy options: the locked premium is debited from PartyA and credited to PartyB, to be paid out after settlement.

• Sell options: the locked maintenance margin is added to PartyA's total maintenance margin for solvency checks, PartyB pays the premium to PartyA, a new trade is created with OPENED status, and the intent moves from LOCKED to FILLED.

Step 4: close position

4.1 Early close (before expiration)

PartyA can close a position early by sending a close intent:

function sendCloseIntent(
uint256 tradeId,
uint256 quantity,
uint256 price,
uint256 deadline
) external

• Buy positions: the premium is paid to PartyB, PartyA sells the option back to PartyB, and PartyB pays PartyA the PnL: PnL = (closePrice − openPrice) × quantity. If PnL < 0, PartyA pays the loss to PartyB.

• Sell positions: the maintenance margin is released to PartyA, and PartyA pays PartyB the PnL (same formula). If PnL < 0, PartyB pays the loss to PartyA.

4.2 Settlement at expiration

function executeTrade(
uint256 tradeId,
SettlementPriceSig memory settlementPriceSig
) external

PartyB keeps the premium it already received (for trades where PartyA was the buyer).

• In-the-money (ITM): the settlement price comes from the oracle, PnL = (settlementPrice − strikePrice) × quantity, and the seller pays the positive PnL to the buyer (or the reverse if negative).

• Out-of-the-money (OTM): the option expires worthless, and any maintenance margin locked by the PartyA seller is released.