fill() - Convallax

Execute an atomic swap between option tokens and USDC on the ConvallaxRFQSettlement contract. The taker calls this function with the signed Order and makerSignature received from POST /execute. Contract: ConvallaxRFQSettlement — 0xC6Eb814Cc01189e20B2DB2D2a22Ed2DcAC404992

Function Signature

function fill(Order calldata order, bytes calldata makerSignature) external

Parameters

order

Order

required

The EIP-712 Order struct signed by the market maker.

Show Order struct

order.maker

address

required

Market maker wallet address.

order.seriesId

uint256

required

Option series ID (= ERC-1155 token ID).

order.optionAmount

uint256

required

Option tokens to swap (6 decimals).

order.premiumAmount

uint256

required

USDC premium to swap (6 decimals).

order.makerSelling

bool

required

true = options flow maker → taker, USDC flows taker → maker.

order.taker

address

required

address(0) for open orders, or a specific taker address.

order.validUntil

uint256

required

Order expiry (Unix timestamp).

order.nonce

uint256

required

Single-use replay protection nonce.

makerSignature

bytes

required

EIP-712 signature from the maker over the Order struct.

Behavior

`makerSelling`	Options flow	USDC flow
`true`	Maker → Taker	Taker → Maker
`false`	Taker → Maker	Maker → Taker

The swap is atomic — both transfers execute in a single transaction or the entire call reverts. The nonce is consumed to prevent replay.

Prerequisites

Before calling fill(), ensure:

USDC approval — The paying party must have approved ConvallaxRFQSettlement to spend their USDC
ERC-1155 approval — The party sending options must have called setApprovalForAll on ConvallaxOptionToken for ConvallaxRFQSettlement
Sufficient balances — Both parties must hold the required token amounts

Example

import { ethers } from 'ethers';

const settlement = new ethers.Contract(
  '0xC6Eb814Cc01189e20B2DB2D2a22Ed2DcAC404992',
  ['function fill(tuple(address maker, uint256 seriesId, uint256 optionAmount, uint256 premiumAmount, bool makerSelling, address taker, uint256 validUntil, uint256 nonce) order, bytes makerSignature) external'],
  signer
);

// order and makerSignature from POST /execute response
const tx = await settlement.fill(order, makerSignature);
await tx.wait();

Nonce Cancellation

Makers can pre-emptively cancel a nonce to prevent a pending order from being filled:

function cancelNonce(uint256 nonce) external

This marks the nonce as used, so any order signed with that nonce will revert with NonceAlreadyUsed if someone tries to fill it.

Reverts

Condition	Reason
`optionAmount` or `premiumAmount` is zero	`InvalidAmount`
Nonce already used or cancelled	`NonceAlreadyUsed`
`block.timestamp > validUntil`	`OrderExpired`
Recovered signer ≠ `order.maker`	`InvalidSignature`
`order.taker` ≠ `address(0)` and ≠ `msg.sender`	`InvalidTaker`
Insufficient balance	ERC-20/ERC-1155 revert

​Function Signature

​Parameters

​Behavior

​Prerequisites

​Example

​Nonce Cancellation

​Reverts

Function Signature

Parameters

Behavior

Prerequisites

Example

Nonce Cancellation

Reverts