OriginSettler

ERC-7683 compliant contract for opening cross-chain intents on the source chain

Overview

The OriginSettler contract is the entry point to Eco Routes Protocol via the ERC-7683 standard. It provides a standardized interface for creating cross-chain orders on the origin chain with enhanced security, replay protection, and proper validation.

Contract Location: contracts/ERC7683/OriginSettler.sol

ERC-7683 Compliance

This contract implements the ERC-7683 Cross-Chain Intent Settlement standard, which defines a universal interface for cross-chain order creation and settlement. It supports both:

• Onchain orders: User directly calls open() to create an intent
• Gasless orders: Solver calls openFor() with user’s EIP-712 signature

Key Features

• EIP-712 Signature Verification: Validates gasless orders using typed structured data hashing
• Replay Protection: Prevents duplicate order execution through vault state checking
• Comprehensive Validation: Checks deadlines, chain IDs, and origin settler addresses
• Unified Funding Logic: Atomic intent creation and funding via _publishAndFund
• ERC-7683 Standard Events: Emits Open event with resolved order data for off-chain solvers

Core Functions

open

function open(OnchainCrossChainOrder calldata order) external payable

Opens a cross-chain order directly on-chain. Called by the user to create and fund an intent atomically.

Parameters:

order · OnchainCrossChainOrder

The cross-chain order containing:

• fillDeadline: Timestamp by which order must be filled
• orderDataType: Must equal ORDER_DATA_TYPEHASH
• orderData: ABI-encoded OrderData struct

Emits:

• Open(bytes32 indexed orderId, ResolvedCrossChainOrder resolvedOrder)

Reverts:

• TypeSignatureMismatch(): If orderDataType doesn’t match expected hash

Usage Example:

OnchainCrossChainOrder memory order = OnchainCrossChainOrder({
    fillDeadline: uint32(block.timestamp + 1 hours),
    orderDataType: ORDER_DATA_TYPEHASH,
    orderData: abi.encode(orderData)
});

originSettler.open{value: rewardAmount}(order);

---

openFor

function openFor(
    GaslessCrossChainOrder calldata order,
    bytes calldata signature,
    bytes calldata originFillerData
) external payable

Opens a gasless cross-chain order on behalf of a user. Called by a solver using the user’s EIP-712 signature.

Parameters:

order · GaslessCrossChainOrder

The gasless order containing:

• originSettler: Must match this contract’s address
• user: Address whose signature is verified
• nonce: Replay protection nonce
• originChainId: Must match current chain ID
• openDeadline: Timestamp by which order must be opened
• fillDeadline: Timestamp by which order must be filled
• orderDataType: Must equal ORDER_DATA_TYPEHASH
• orderData: ABI-encoded OrderData struct

signature · bytes

User’s EIP-712 signature authorizing the order creation

originFillerData · bytes

Optional filler-defined data (currently unused)

Emits:

• Open(bytes32 indexed orderId, ResolvedCrossChainOrder resolvedOrder)

Reverts:

• OpenDeadlinePassed(): If current timestamp exceeds openDeadline
• InvalidOriginSettler(address expected, address actual): If originSettler doesn’t match this contract
• InvalidOriginChainId(uint256 expected, uint256 actual): If originChainId doesn’t match current chain
• TypeSignatureMismatch(): If orderDataType doesn’t match expected hash
• InvalidSignature(): If signature verification fails

Replay Protection:

The contract includes built-in replay protection:

1. If intent is Withdrawn or Refunded, transaction fails
2. If intent is Initial, it publishes and funds the intent
3. If intent is Funded, it publishes but doesn’t double-fund

---

resolve

function resolve(
    OnchainCrossChainOrder calldata order
) public view returns (ResolvedCrossChainOrder memory)

Resolves an onchain order into ERC-7683 compliant ResolvedCrossChainOrder format for off-chain solvers.

Parameters:

order · OnchainCrossChainOrder

The order to resolve

Returns:

---

resolveFor

function resolveFor(
    GaslessCrossChainOrder calldata order,
    bytes calldata originFillerData
) external view returns (ResolvedCrossChainOrder memory)

Resolves a gasless order into ERC-7683 compliant format.

Parameters:

order · GaslessCrossChainOrder

The gasless order to resolve

originFillerData · bytes

Optional filler data (currently unused)

Returns:

---

domainSeparatorV4

function domainSeparatorV4() public view returns (bytes32)

Returns the EIP-712 domain separator used for signature verification.

Returns:

---

Abstract Methods

_publishAndFund

function _publishAndFund(
    uint64 destination,
    bytes memory route,
    Reward memory reward,
    bool allowPartial,
    address funder
) internal virtual returns (bytes32 intentHash, address vault)

Core method for atomic intent creation and funding. Must be implemented by derived contracts.

Parameters:

destination · uint64

Destination chain ID where the intent should be executed

route · bytes

Encoded route data containing execution instructions for destination chain

reward · Reward

Reward structure containing token amounts, creator, prover, and deadline

allowPartial · bool

Whether to accept partial funding if full funding is not possible

funder · address

Address providing the funding (msg.sender for open(), order.user for openFor())

Returns:

intentHash · bytes32

Unique identifier of the created or existing intent

vault · address

Address of the intent’s vault contract for reward escrow

---

Events

Open

event Open(bytes32 indexed orderId, ResolvedCrossChainOrder resolvedOrder)

Emitted when an order is successfully opened via open() or openFor().

Parameters:

orderId · bytes32 indexed

Unique identifier for the order (intent hash)

resolvedOrder · ResolvedCrossChainOrder

ERC-7683 compliant resolved order data for off-chain solvers

---

Errors

TypeSignatureMismatch

error TypeSignatureMismatch()

Thrown when orderDataType doesn’t match ORDER_DATA_TYPEHASH.

InvalidOriginChainId

error InvalidOriginChainId(uint256 expected, uint256 actual)

Thrown when the origin chain ID in the order doesn’t match the current chain.

OpenDeadlinePassed

error OpenDeadlinePassed()

Thrown when attempting to open an order after the openDeadline has passed.

InvalidSignature

error InvalidSignature()

Thrown when EIP-712 signature verification fails.

InvalidOriginSettler

error InvalidOriginSettler(address expected, address actual)

Thrown when the originSettler address in the order doesn’t match this contract.

InsufficientNativeRewardAmount

error InsufficientNativeRewardAmount()

Thrown when sent native token amount is less than required reward amount.

---

EIP-712 Type Hashes

GASLESS_CROSSCHAIN_ORDER_TYPEHASH

bytes32 public GASLESS_CROSSCHAIN_ORDER_TYPEHASH = keccak256(
    "GaslessCrossChainOrder(address originSettler,address user,uint256 nonce,uint256 originChainId,uint32 openDeadline,uint32 fillDeadline,bytes32 orderDataType,bytes32 orderDataHash)"
)

EIP-712 type hash for gasless cross-chain orders used in signature verification.

---

Implementation Notes

Security Features

1. Replay Protection: The _publishAndFund method checks vault state to prevent duplicate funding
2. Deadline Validation: Both open and fill deadlines are validated to ensure timely execution
3. Chain ID Verification: Ensures orders are executed on the correct chain
4. Signature Verification: Uses EIP-712 for secure off-chain authorization

Gas Optimization

• Uses uint32 for timestamps (safe until year 2106)
• Efficient ABI encoding/decoding of nested structs
• Direct orderData.maxSpent usage instead of reconstruction

Integration Guide

To integrate with OriginSettler:

1. Encode your OrderData with destination, route, reward, portal, deadline, and maxSpent
2. For onchain orders: call open() with proper msg.value for native rewards
3. For gasless orders: obtain user’s EIP-712 signature and call openFor()
4. Listen for Open events to track order creation
5. Use resolve() or resolveFor() to get standardized order format for solvers

---

Related

• DestinationSettler - Settlement contract on destination chain
• OrderData Type - Order data structure
• Reward Type - Reward structure
• ERC-7683 Standard - Official EIP specification