Utilities - ZKsync Docs

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

During a normal transaction, if contract A calls contract B, the msg.sender is A.
During L1->L2 communication, if an EOA X calls contract B, the msg.sender is X.
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.

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`	Structured data.
`signature`	`String`	Signature.

Example

final String signature = "0x4355c47d63924e8a72e509b65029052eb6c299d53a04e167c5775fd466751c9d07299936d304c153f6443dfa05f40ff007d72911b6f72307f996231605b915621c";

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

Contract Interfaces

System contracts for interacting with the ZKsync Era network

Paymaster Utilities

Essential utilities for using paymasters on ZKsync Era