Java API

Utilities

Essential utilities for building on the ZKsync Era

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

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

ParameterTypeDescription
addressStringContract 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

ParameterTypeDescription
addressStringSender 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

ParameterTypeDescription
baseCostBigIntegertransaction's base cost.
valueBigIntegervalue 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

ParameterTypeDescription
tokenAddressToken address.
amountBigNumberishDeposit amount.
toAddressRecipient address.
providerL2ZkSyncZKsync provider.
bridgeContractsL1BridgeContractsL1 bridge contract contracts.
providerL1Web3jEthers provider.
credentialsCredentialsSender credentials (optional).
gasProviderContractGasProviderContract gas provider (optional).
fromAddressSender address (optional).
gasPerPubdataByteBigNumberishCurrent gas per byte of pubdata (optional).

getERC20BridgeCalldata

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

Inputs

ParameterTypeDescription
l1TokenAddressStringToken address on L1.
l1SenderStringSender address on L1.
l2ReceiverStringRecipient address on L2.
amountBigIntegerGas fee for the number of tokens to bridge.
bridgeDatabyte[]Data

ContractDeployer

create2Address

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

The ZKsync Era implementation is slightly different from Ethereum.

Inputs

ParameterTypeDescription
senderAddressSender address.
bytecodebyte[]Output from zkSolc.
constructorbyte[]ABI encoded contrusctor arguments
saltbyte[]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

ParameterTypeDescription
senderAddressSender address.
nonceBigIntegerSender 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

ParameterTypeDescription
signatureStringSignature string.
messagebyte[]Message bytes.
prefixedbooleanIs prefixed.

verifyTypedData

Returns true if account abstraction EIP712 signature is correct.

Inputs

ParameterTypeDescription
domainEip712DomainDomain data.
typedDataSStructurable data.
signatureStringSignature.

Example

final String signature = "0x4355c47d63924e8a72e509b65029052eb6c299d53a04e167c5775fd466751c9d07299936d304c153f6443dfa05f40ff007d72911b6f72307f996231605b915621c";

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

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