Utils

Provides essential utilities for building on zkSync Era.

Constants

L1 to L2 alias offset

Used for applying and undoing aliases on contract addresses during bridging from L1 to L2.

L1ToL2AliasOffset := common.HexToAddress("0x1111000000000000000000000000000000001111")

Useful addresses

ETH token on L1

EthAddress := common.HexToAddress("0x0000000000000000000000000000000000000000")

ETH token alias on ZkSync Era

L2EthTokenAddress := common.HexToAddress("0x000000000000000000000000000000000000800a")

Bootloader

BootloaderFormalAddress := common.HexToAddress("0x0000000000000000000000000000000000008001")

Contract deployer

ContractDeployerAddress := common.HexToAddress("0x0000000000000000000000000000000000008006")

L1 messenger

L1MessengerAddress := common.HexToAddress("0x0000000000000000000000000000000000008008")

Nonce holder

NonceHolderAddress := common.HexToAddress("0x0000000000000000000000000000000000008003")

Gas

DefaultGasPerPubdataLimit

• Use a large amount of gas per pubdata for signing on layer 2.
• The amount ensures any reasonable limit is accepted.

Info

The operator is NOT required to use the actual value and can use any value up to that signed by the user.

DefaultGasPerPubdataLimit := big.NewInt(50_000)

RequiredL1ToL2GasPerPubdataLimit

The current required gas per pubdata for L1->L2 transactions.

RequiredL1ToL2GasPerPubdataLimit := big.NewInt(800)

Functions

ApplyL1ToL2Alias

Converts the address that submitted a transaction to the inbox on L1 to the msg.sender viewed on L2.

Inputs

Parameter	Type	Description
address	common.Address	Contract address.

Outputs

Returns the msg.sender of the L1->L2 transaction as the common.Address of the contract that initiated the transaction.

More info

1. During a normal transaction, if contract A calls contract B, the msg.sender is A.
2. During L1->L2 communication, if an EOA X calls contract B, the msg.sender is X.
3. During L1->L2 communication, if a contract A calls contract B, the msg.sender is ApplyL1ToL2Alias(A).

func ApplyL1ToL2Alias(address common.Address) common.Address

See also UndoL1ToL2Alias.

Create2Address

Generates a future-proof contract address using salt plus bytecode which allows determination of an address before deployment.

Note

The zkSync Era implementation is slightly different from Ethereum.

Inputs

Parameter	Type	Description
sender	common.Address	Sender address.
bytecode	[]byte	Output from zkSolc.
constructor	[]byte	ABI encoded constructor arguments.
salt	[]byte	Randomization element.

Outputs

Returns a common.Address of the future contract.

func Create2Address(sender common.Address, bytecode, constructor, salt []byte) (common.Address, error)

Tips

The prefix is equal to keccak256("zksyncCreate2").

CreateAddress

Generates a contract address from deployer's account and nonce.

Inputs

Parameter	Type	Description
sender	common.Address	Sender address.
nonce	*big.Int object	Sender nonce.

Outputs

Returns a common.Address of the future contract.

func CreateAddress(sender common.Address, nonce *big.Int) (common.Address, error)

Tips

The prefix is equal to keccak256("zksyncCreate").

CreateETH

Creates ETH token with appropriate Name, Symbol and Decimals values.

func CreateETH() *types.Token

EncodeCreate

Returns the encoded constructor data for CREATE method used for smart contract deployment.

Inputs

Parameter	Type	Description
bytecode	[]byte	Output from zkSolc.
calldata	[]byte	ABI encoded constructor arguments.

func EncodeCreate(bytecode, calldata []byte) ([]byte, error)

EncodeCreate2

Returns the encoded constructor data for CREATE2 method used for smart contract deployment.

Inputs

Parameter	Type	Description
bytecode	[]byte	Output from zkSolc.
calldata	[]byte	ABI encoded constructor arguments.
salt	[]byte	Randomization element.

func EncodeCreate2(bytecode, calldata, salt []byte) ([]byte, error)

EncodeCreateAccount

Returns the encoded constructor data for CREATE method used for smart account deployment.

Inputs

Parameter	Type	Description
bytecode	[]byte	Output from zkSolc.
calldata	[]byte	ABI encoded constructor arguments.
version	types.AccountAbstractionVersion	Account abstraction version.

 EncodeCreate2Account(bytecode, calldata, version types.AccountAbstractionVersion) ([]byte, error)

EncodeCreate2Account

Returns the encoded constructor data for CREATE2 method used for smart account deployment.

Inputs

Parameter	Type	Description
bytecode	[]byte	Output from zkSolc.
calldata	[]byte	ABI encoded constructor arguments.
salt	[]byte	Randomization element.
version	types.AccountAbstractionVersion	Account abstraction version.

 EncodeCreate2Account(bytecode, calldata, salt []byte, version types.AccountAbstractionVersion) ([]byte, error)

Erc20BridgeCalldata

Returns the calldata sent by an L1 ERC20 bridge to its L2 counterpart during token-bridging.

Inputs

Parameter	Type	Description
l1TokenAddress	common.Address	Token address on L1.
l1Sender	common.Address	Sender address on L1.
l2Receiver	common.Address	Recipient address on L2.
amount	*big.Int	Gas fee for the number of tokens to bridge.
bridgeData	*big.Int	Data

func Erc20BridgeCalldata(l1TokenAddress, l1Sender, l2Receiver common.Address, amount *big.Int, bridgeData []byte)

Erc20DefaultBridgeData

Returns the data needed for correct initialization of an L1 token counterpart on L2.

Inputs

Parameter	Type	Description
l1TokenAddress	common.Address	Token address on L1.
backend	bind.ContractBackend	Client that is able to work with contracts on a read-write basis.

Outputs

An ABI-encoded []byte which contains token name, symbol and decimals.

func Erc20DefaultBridgeData(l1TokenAddress common.Address, backend bind.ContractBackend) ([]byte, error)

HashBytecode

Returns the hash of given bytecode.

Inputs

Parameter	Type	Description
bytecode	[]byte	Bytecode.

func HashBytecode(bytecode []byte) ([]byte, error)

ReadStandardJson

Reads standard-json file generated as output from zksolc. Returns standard json configuration and extracted contracts abi and bytecode from config file.

Inputs

Parameter	Type	Description
path	string	Path to the standard-json file.

func ReadStandardJson(path string) (*types.StandardConfiguration, abi.ABI, []byte, error)

UndoL1ToL2Alias

Converts and returns the msg.sender viewed on L2 to the address that submitted a transaction to the inbox on L1.

Inputs

Parameter	Type	Description
address	common.Address	Sender address.

Outputs

Returns the msg.sender of the L2->L1 transaction as the common.Address of the contract that initiated the transaction.

func UndoL1ToL2Alias(address common.Address) common.Address

See also ApplyL1ToL2Alias.