L1SenderV2

Introduction

The L1SenderV2 contract serves as a critical component in the cross-chain infrastructure of the protocol. Its primary responsibility is to transfer both reward data and yield assets from Ethereum (L1) to Arbitrum (L2), ensuring that users receive accurate MOR token rewards and that the protocol’s yield is available for conversion and distribution on L2.

The contract automatically receives deposit tokens from the Distributor contract. These tokens represent the yield generated by various DepositPools and may come in different ERC-20 formats depending on the underlying staking strategy. To unify these assets for bridging, the L1SenderV2 integrates with Uniswap v3, enabling it to swap the received tokens into wstETH. Once converted, the resulting wstETH is sent through the Arbitrum Bridge to the L2TokenReceiverV2 contract on Arbitrum, ensuring the protocol’s yield is properly transferred and made available for liquidity and reward mechanisms on L2.

Key Responsibilities

  1. Cross-chain reward messaging via LayerZero:

    • The contract communicates with the L2MessageReceiver on Arbitrum using LayerZero.

    • It packages the user’s reward data (including recipient address and reward amount) and sends it securely across chains.

    • This action is triggered by the DepositPool contract after calculating a user’s rewards.

    • On arrival to L2, the message is decoded, and MOR tokens are minted to the user.

  2. Bridging stETH yield via Arbitrum Bridge:

    • The contract manages the bridging of yield generated from stETH held by the Morpheus protocol.

    • It wraps stETH into wstETH and uses Arbitrum Bridge to transfer tokens to the L2TokenReceiver contract.

  3. Token configuration management:

    • The contract stores configuration data for both deposit and reward tokens:

      • Deposit token: the wrapped stETH token to be bridged.

      • Reward token: LayerZero configuration for sending mint instructions.

    • It handles dynamic updates to these configurations, allowing the protocol to change tokens or gateways without redeploying the contract.

  4. Automated deposit handling:

    Receives various yield tokens directly from the Distributor contract.

  5. Uniswap V3 integration for token conversion:

    Swaps received tokens into wstETH before bridging to L2.

Storage

stETH

The address of the original deposit token (e.g., stETH) before it is wrapped for cross-chain transfer.

address public stETH;

distributor

The address of the Distributor contract.

address public distributor;

arbitrumBridgeConfig

Configuration details for bridging the stETH token via Arbitrum Bridge.

ArbitrumBridgeConfig public arbitrumBridgeConfig;

struct ArbitrumBridgeConfig {
  address token;
  address gateway;
  address receiver;
}
Name
Description

token

The address of wstETH.

gateway

The address of token's gateway, L1GatewayRouter

receiver

The L2MessageReceiver address.

layerZeroConfig

Configuration for the LayerZero cross-chain messaging.

LayerZeroConfig public layerZeroConfig;

struct LayerZeroConfig {
  address gateway;
  address receiver;
  uint16 receiverChainId;
  address zroPaymentAddress;
  bytes adapterParams;
}
Name
Description

gateway

The LayerZero EnpointV1 address.

receiver

The L2MessageReceiver address.

receiverChainId

The receiver chain ID, from the LZ doc.

zroPaymentAddress

The LayerZero ZRO payment address for gas fees.

adapterParams

LayerZero adapter parameters used to customize messaging behavior.

Write functions for the contract owner

L1SenderV2__init

Initializes the contract. This is a one-time setup function, used during deployment via proxies.

function L1SenderV2__init() external initializer

setStETh

Allows the contract owner to set or update the address of the stETH token.

function setStETh(address value_) external onlyOwner
Name
Description

value_

The stETH token address

setDistributor

Allows the contract owner to set or update the address of the Distributor contract.

function setDistributor(address value_) public onlyOwner
Name
Description

value_

The Distributor contract address

setUniswapSwapRouter

Allows the contract owner to set the Uniswap v3 SwapRouter contract address.

function setUniswapSwapRouter(address value_) external onlyOwner
Name
Description

value_

The SwapRouter contract address

setLayerZeroConfig

Allows the contract owner to update the LayerZero MOR token configuration used for cross-chain messaging.

function setLayerZeroConfig(
  LayerZeroConfig calldata layerZeroConfig_
) external onlyOwner
Name
Description

layerZeroConfig_

Configuration for the LayerZero cross-chain messaging.

setArbitrumBridgeConfig

Allows the contract owner to update the Arbitrum Bridge configuration.

function setArbitrumBridgeConfig(
  ArbitrumBridgeConfig calldata newConfig_
) external onlyOwner
Name
Description

newConfig_

Configuration details for bridging the stETH token.

sendWstETH

Transfers tokens on the contract balance (e.g., stETH and wstETH) from L1 to L2 using the Arbitrum Bridge.

function sendWstETH(
  uint256 gasLimit_,
  uint256 maxFeePerGas_,
  uint256 maxSubmissionCost_
) external payable onlyOwner returns (bytes memory)
Name
Description

gasLimit_

Gas limit for the L2 execution.

maxFeePerGas_

Max fee for L2 execution.

maxSubmissionCost_

Base submission cost for the retryable ticket.

swapExactInputMultihop

Allows the contract owner to swap deposit asset to the wstETH via Uniswap v3. Support multihop swaps (e.g. USDC/wETH, wETH/wstETH).

function swapExactInputMultihop(
  address[] calldata tokens_,
  uint24[] calldata poolsFee_,
  uint256 amountIn_,
  uint256 amountOutMinimum_,
  uint256 deadline_
) external onlyOwner returns (uint256)
Name
Description

tokens_

Tokens addresses. [USDC, wETH, wstETH]

poolsFee_

Uniswap v3 pool fee (e.g., 3000 = 0.3%).

amountIn_

The input token amount to swap. See the token decimals for the precision.

amountOutMinimum_

The minimal tokens amount at the end of swap (wstETH). See the token decimals for the precision.

deadline_

Expiry timestamp in seconds for the transaction.

Write functions for the Distributor contract

sendMintMessage

Sends a cross-chain message via LayerZero to L2, instructing minting of MOR tokens to the user.

function sendMintMessage(
  address user_, 
  uint256 amount_, 
  address refundTo_
) external payable
Name
Description

user_

Recipient address on L2.

amount_

Amount of tokens to mint. Wei.

refundTo_

Address that receives any unspent msg.value.

Read functions

supportsInterface

Used for interface detection (ERC165). Returns true if the contract supports a specific interfaceId_. Supports IL1SenderV2, IERC165.

function supportsInterface(bytes4 interfaceId_) external pure returns (bool)

version

Returns the current version of the contract.

function version() external pure returns (uint256)

Last updated

Was this helpful?