Utilities

The utilities package contains essential utilities for building on zkSync Era.

Info

• This document describes common functions and constants you may need.
• Functions used internally are not necessarily described.
• Check the code for the full list.

Use the library

Access the package by importing it into your scripts.

import io.zksync.utils.*;

Constants

EIP712 structures

Collection of EIP712 structures with their types.

export const EIP712_TYPES = {
  Transaction: [
    { name: "txType", type: "uint256" },
    { name: "from", type: "uint256" },
    { name: "to", type: "uint256" },
    { name: "gasLimit", type: "uint256" },
    { name: "gasPerPubdataByteLimit", type: "uint256" },
    { name: "maxFeePerGas", type: "uint256" },
    { name: "maxPriorityFeePerGas", type: "uint256" },
    { name: "paymaster", type: "uint256" },
    { name: "nonce", type: "uint256" },
    { name: "value", type: "uint256" },
    { name: "data", type: "bytes" },
    { name: "factoryDeps", type: "bytes32[]" },
    { name: "paymasterInput", type: "bytes" },
  ],
};

ZkSyncAddresses

ETH token layer 1

public static final String ETH_ADDRESS = "0x0000000000000000000000000000000000000000";

ETH token alias on ZkSync Era

public static final String L2_ETH_TOKEN_ADDRESS = "0x000000000000000000000000000000000000800a";

Contract deployer

public static final String CONTRACT_DEPLOYER_ADDRESS = "0x0000000000000000000000000000000000008006";

L1 messenger

public static final String MESSENGER_ADDRESS = "0x0000000000000000000000000000000000008008";

Nonce holder

public static final String NONCE_HOLDER_ADDRESS = "0x0000000000000000000000000000000000008003";

WalletUtils

applyL1ToL2Alias

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

Returns the msg.sender of the L1->L2 transaction as the 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).

Inputs

Parameter	Type	Description
address	String	Contract address.

Example

String nonZeroPadded = WalletUtils.applyL1ToL2Alias("0x702942B8205E5dEdCD3374E5f4419843adA76Eeb");

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	String	Sender address.

Example

String nonZeroPadded = WalletUtils.undoL1ToL2Alias("0x813A42B8205E5DedCd3374e5f4419843ADa77FFC");

checkBaseCost

Checks if the transaction's base cost is greater than the provided value, which covers the transaction's cost. Throws an error if it is not.

Inputs

Parameter	Type	Description
baseCost	BigInteger	transaction's base cost.
value	BigInteger	value which covers the transaction's cost.

Example

BigInteger baseCost = BigInteger.valueOf(100);
BigInteger value = BigInteger.valueOf(99);

try {
  WalletUtils.checkBaseCost(baseCost, value);
} catch (Exception e) {
  // e.message = `The base cost of performing the priority operation is higher than the provided value parameter for the transaction: baseCost: ${baseCost}, provided value: ${value}`,
}

estimateDefaultBridgeDepositL2Gas

Returns an estimation of L2 gas required for token bridging via the default ERC20 bridge.

Inputs

Parameter	Type	Description
token	Address	Token address.
amount	BigNumberish	Deposit amount.
to	Address	Recipient address.
providerL2	ZkSync	zkSync provider.
bridgeContracts	L1BridgeContracts	L1 bridge contract contracts.
providerL1	Web3j	Ethers provider.
credentials	Credentials	Sender credentials (optional).
gasProvider	ContractGasProvider	Contract gas provider (optional).
from	Address	Sender address (optional).
gasPerPubdataByte	BigNumberish	Current gas per byte of pubdata (optional).

getERC20BridgeCalldata

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

Inputs

Parameter	Type	Description
l1TokenAddress	String	Token address on L1.
l1Sender	String	Sender address on L1.
l2Receiver	String	Recipient address on L2.
amount	BigInteger	Gas fee for the number of tokens to bridge.
bridgeData	byte[]	Data

ContractDeployer

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	Address	Sender address.
bytecode	byte[]	Output from zkSolc.
constructor	byte[]	ABI encoded contrusctor arguments
salt	byte[]	Randomization element.

Example

Address result = ContractDeployer.computeL2Create2Address(new Address("0xa909312acfc0ed4370b8bd20dfe41c8ff6595194"), Numeric.hexStringToByteArray
("0x010001cb6a6e8d5f6829522f19fa9568660e0a9cd53b2e8be4deb0a679452e41"), new byte[] {}, new byte[32]);

createAddress

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

Inputs

Parameter	Type	Description
sender	Address	Sender address.
nonce	BigInteger	Sender nonce.

export function createAddress(sender: Address, senderNonce: BigNumberish): string;

Example

Address result = ContractDeployer.computeL2CreateAddress(new Address("0x7e5f4552091a69125d5dfcb7b8c2659029395bdf"), BigInteger.valueOf(1));

verifySignature

Called from verifyTypedData. Returns true if account abstraction EIP712 signature is correct.

Inputs

Parameter	Type	Description
signature	String	Signature string.
message	byte[]	Message bytes.
prefixed	boolean	Is prefixed.

verifyTypedData

Returns true if account abstraction EIP712 signature is correct.

Inputs

Parameter	Type	Description
domain	Eip712Domain	Domain data.
typedData	S	Structurable data.
signature	String	Signature.

Example

final String signature = "0x4355c47d63924e8a72e509b65029052eb6c299d53a04e167c5775fd466751c9d07299936d304c153f6443dfa05f40ff007d72911b6f72307f996231605b915621c";

boolean verified = key.verifyTypedData(domain, message, signature).join();