Contract

Functions

getChainId

  function getChainId(  ) public view override returns (uint256 _chainId)

Gets the chain id of this contract. If not specified during init, will use the block.chainId.

getStoredChainId

  function getStoredChainId(  ) external view override returns (uint256)

Gets the chain id that this contract has stored.

addRouter

  function addRouter(    address router  ) external override onlyOwner

Adds a router to the router list that can transact crosschain.

Parameters:

Name	Type	Description
router	address	The router address to add

removeRouter

  function removeRouter(    address router  ) external override onlyOwner

Removes a router from the router list that can transact crosschain.

Parameters:

Name	Type	Description
router	address	The router address to remove

addAssetId

  function addAssetId(    address assetId  ) external override onlyOwner

Adds an asset to the asset list that can be transferred

• The asset address should be on the same chain as the contract.

Parameters:

Name	Type	Description
assetId	address	The asset address to add to the list

removeAssetId

  function removeAssetId(    address assetId  ) external override onlyOwner

Removes an asset from the asset list that can be transferred

• The asset address should be on the same chain as the contract.

Parameters:

Name	Type	Description
assetId	address	The asset address to remove from the list

addLiquidityFor

  function addLiquidityFor(    uint256 amount,    address assetId,    address router  ) external payable override nonReentrant

Adds liquidity to a router.

Parameters:

Name	Type	Description
amount	uint256	The amount of assetId to add as liquidity
assetId	address	The address (or address(0) for native asset) of the asset to add
router	address	The router to add liquidity

addLiquidity

  function addLiquidity(    uint256 amount,    address assetId  ) external payable override nonReentrant

Adds liquidity to a router.

This function should be called from a router, since it passes msg.sender as a router to _addLiquidityForRouter.

Parameters:

Name	Type	Description
amount	uint256	The amount of assetId to add as liquidity
assetId	address	The address (or address(0) for native asset) of the asset to add

removeLiquidity

  function removeLiquidity(    uint256 amount,    address assetId,    address payable recipient  ) external override nonReentrant

Removes liquidity from a router.

This function should be called from a router.

Parameters:

Name	Type	Description
amount	uint256	The amount of assetId to remove as liquidity
assetId	address	The address (or address(0) for native asset) of the asset to remove
recipient	address	The address to transfer removed liquidity to

prepare

  function prepare(    PrepareArgs calldata args  ) external payable override nonReentrant returns (TransactionData memory)

Creates a crosschain transaction.

When called on the sending chain, the user is expected to lock up funds. When called on the receiving chain, the router deducts the transfer amount from the available liquidity. The majority of the information about a given transfer does not change between chains, with three notable exceptions: amount, expiry, and preparedBlock. The amount and expiry are decremented between sending and receiving chains to provide an incentive for the router to complete the transaction and time for the router to fulfill the transaction on the sending chain after the unlocking signature is revealed, respectively.

Parameters:

Name	Type	Description
args	struct ITransactionManager.PrepareArgs	The parameters for crosschain transaction, encoded as PrepareArgs in calldata

Return Values:

Name	Type	Description
	struct ITransactionManager.TransactionData	The transaction data

fulfill

  function fulfill(    FulfillArgs calldata args  ) external override nonReentrant returns (TransactionData memory)

Completes a crosschain transaction.

When called on the receiving chain, the user reveals their signature on the transactionId and is sent the amount corresponding to the number of shares the router locked when calling prepare. The router then uses this signature to unlock the corresponding funds on the receiving chain, which are then added back to their available liquidity. The user includes a relayer fee since it is not assumed they will have gas on the receiving chain. This function must be called before the transaction expiry has elapsed.

Parameters:

Name	Type	Description
args	struct ITransactionManager.FulfillArgs	The parameters for completing a crosschain transaction, encoded as FulfillArgs in calldata

Return Values:

Name	Type	Description
	struct ITransactionManager.TransactionData	The transaction data

cancel

  function cancel(    CancelArgs calldata args  ) external override nonReentrant returns (TransactionData memory)

Cancels a crosschain transaction.

Any crosschain transaction can be cancelled after it has been created to prevent indefinite lock up of funds. After the transaction has expired, anyone can cancel it. Before the expiry, only the recipient of the funds on the given chain is able to cancel. On the sending chain, this means only the router is able to cancel before the expiry, while only the user can prematurely cancel on the receiving chain.

Parameters:

Name	Type	Description
args	struct ITransactionManager.CancelArgs	The parameters for canceling a crosschain transaction, encoded as CancelArgs in calldata

Return Values:

Name	Type	Description
	struct ITransactionManager.TransactionData	The transaction data

_addLiquidityForRouter

  function _addLiquidityForRouter(    uint256 amount,    address assetId,    address router  ) internal

Adds liquidity to a router. This is a helper function containing the logic to verify, and to add liquidity to a given router.

Parameters:

Name	Type	Description
amount	uint256	The amount of assetId to add as liquidity
assetId	address	The address (or address(0) for native asset) of the asset to add
router	address	The router to add liquidity

transferAssetToContract

  function transferAssetToContract(    address assetId,    uint256 specifiedAmount  ) internal returns (uint256)

This is a helper function to handle transferring funds from msg.sender to the transaction manager contract. It is used in prepare, _addLiquidityForRouter.

Parameters:

Name	Type	Description
assetId	address	The address (or address(0) for native asset) of the asset to transfer
specifiedAmount	uint256	The amount of assetId to transfer

Return Values:

Name	Type	Description
	uint256	The amount of the asset that has been transferred

recoverCancelSignature

  function recoverCancelSignature(    bytes32 transactionId,    uint256 receivingChainId,    address receivingChainTxManagerAddress,    bytes calldata signature  ) internal pure returns (address)

This is a helper function to recover the signer address from the signature.

Parameters:

Name	Type	Description
transactionId	bytes32	The transaction identifier of the recovering transaction
receivingChainId	uint256	The receiving chain id
receivingChainTxManagerAddress	address	The transaction manager address on the receiving chain
signature	bytes	The signature to recover the signer address from

Return Values:

Name	Type	Description
	address	The signer address of the signature

recoverFulfillSignature

  function recoverFulfillSignature(    bytes32 transactionId,    uint256 relayerFee,    uint256 receivingChainId,    address receivingChainTxManagerAddress,    bytes calldata signature  ) internal pure returns (address)

This is a helper function to recover the signer address from the signature.

Parameters:

Name	Type	Description
transactionId	bytes32	The transaction identifier of the recovering transaction
relayerFee	uint256	The fee paid to the relayer for submitting the transaction for the user
receivingChainId	uint256	The receiving chain id
receivingChainTxManagerAddress	address	The transaction manager address on the receiving chain
signature	bytes	The signature to recover the signer address from

Return Values:

Name	Type	Description
	address	The signer address of the signature

recoverSignature

  function recoverSignature(    bytes memory encodedPayload,    bytes calldata signature  ) internal pure returns (address)

This is a helper function to recover the signer address from the signature and the encodedPayload.

Parameters:

Name	Type	Description
encodedPayload	bytes	The encoded payload that was signed
signature	bytes	The signature to recover the signer address from

Return Values:

Name	Type	Description
	address	The signer address of the signature

hashInvariantTransactionData

  function hashInvariantTransactionData(    TransactionData calldata txData  ) internal pure returns (bytes32)

This is a helper function to get the hash of only the invariant portions of a given crosschain transaction.

Parameters:

Name	Type	Description
txData	struct ITransactionManager.TransactionData	The transaction data, encoded as TransactionData in calldata

Return Values:

Name	Type	Description
	bytes32	The hash of the invariant transaction data

hashVariantTransactionData

  function hashVariantTransactionData(    uint256 amount,    uint256 expiry,    uint256 preparedBlockNumber  ) internal pure returns (bytes32)

This is a helper function to get the hash of only the variant portions of a given crosschain transaction.

Parameters:

Name	Type	Description
amount	uint256	The amount of the transaction
expiry	uint256	The expiry of the transaction
preparedBlockNumber	uint256	The prepared block number

Return Values:

Name	Type	Description
	bytes32	The hash of the variant transaction data

_receivingChainFulfill

  function _receivingChainFulfill(    TransactionData calldata txData,    uint256 relayerFee,    bytes calldata callData  ) internal returns (bool, bool, bytes memory)

This is a helper function to handle the receiving-chain fulfillment. This function should pay the relayer and either send funds to the specified address or execute the calldata. Returns a tuple of boolean, bytes indicating the success and return data of the external call.

Parameters:

Name	Type	Description
txData	struct ITransactionManager.TransactionData	The transaction data, encoded as TransactionData in calldata
relayerFee	uint256	The fee paid to the relayer for submitting the transaction for the user
callData	bytes	The prepared block number

Return Values:

Name	Type	Description
	bool	The result of calling the external call (false if it is simply sending funds)
	bool	True if it is external call and the txData.callTo is a contract
	bytes	The return data of the external call