fill()

Execute an option trade in a single atomic transaction on the ConvallaxRFQSettlement contract. The taker calls this function with the signed Order and makerSignature received from POST /quote-requests/:id/commit. fill() is atomic mint-on-fill: it calls ConvallaxCore.mintFor(...) to pull collateral from the writer, mint fresh option tokens to the holder, and move the premium — all or nothing. Option tokens are minted on demand; there is no pre-minted inventory and no token transfer between parties. Contract: ConvallaxRFQSettlement — 0x3E583BC44157c91F8c534372A3e91c371841107A

Function Signature

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

Parameters

Order

required

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

Show Order struct

address

required

Market maker wallet address.

uint256

required

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

uint256

required

Option tokens to mint (6 decimals).

uint256

required

USDC premium to pay (6 decimals).

bool

required

true = taker goes long: the maker posts collateral, the option is minted to the taker, and premium flows taker → maker. false = taker goes short: the taker posts collateral, the option is minted to the maker, and premium flows maker → taker.

address

required

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

uint256

required

Order expiry (Unix timestamp).

uint256

required

Single-use replay protection nonce.

bytes

required

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

Behavior

Internally, fill() calls ConvallaxCore.mintFor(seriesId, optionAmount, writer, holder), which pulls collateral from the writer, mints fresh option tokens to the holder, and records the writer for writer claims at settlement. The settlement contract moves the premium separately.

`makerSelling`	Direction	Collateral poster (writer)	Tokens minted to (holder)	Premium flow
`true`	Taker goes long	Maker → Core	Taker	Taker → Maker
`false`	Taker goes short	Taker → Core	Maker	Maker → Taker

The fill is atomic — collateral, premium, and minting all execute in a single transaction or the entire call reverts. Collateral is locked only when the trade executes. The nonce is consumed to prevent replay.

Prerequisites

Settlement requires two USDC approvals — there are no ERC-1155 / setApprovalForAll approvals. Each party approves only the contract relevant to its role:

Collateral approval — The party posting collateral (the writer) must usdc.approve(coreAddress, collateral) so ConvallaxCore can pull it.
Premium approval — The party paying premium must usdc.approve(settlementAddress, premium) so ConvallaxRFQSettlement can pull it.
Sufficient balances — Both parties must hold enough USDC for their respective obligations.

For a standard long fill (makerSelling = true): the maker approves Core (collateral) and the taker approves Settlement (premium). For a short fill (makerSelling = false): the taker approves Core (collateral) and the maker approves Settlement (premium).

A market maker that quotes both directions should approve both Core (collateral) and Settlement (premium) for USDC.

The collateral amount equals the writer’s maximum loss:

Call:  collateral = optionAmount × (100 − strikeBps) / 100
Put:   collateral = optionAmount × strikeBps / 100

(6-decimal raw USDC units, integer division.)

Example

import { ethers } from 'ethers';

const settlement = new ethers.Contract(
  '0x3E583BC44157c91F8c534372A3e91c371841107A',
  ['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 /quote-requests/:id/commit 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

Overview

Series

Trading

Market Maker

User

Settlement

On-Chain Contracts

Testnet

Function Signature

Parameters

Behavior

Prerequisites

Example

Nonce Cancellation

Reverts

​Function Signature

​Parameters

​Behavior

​Prerequisites

​Example

​Nonce Cancellation

​Reverts

Function Signature

Parameters

Behavior

Prerequisites

Example

Nonce Cancellation

Reverts