Contract interfaces

There is a set of system contract that helps with the interaction with zkSync Era network.
The following are the contracts:

• NonceHolder
• ERC20Contract & ERC20FunctionEncoder
• ContractDeployer

NonceHolder

The NonceHolder system contract handles the deployment of nonce, it's useful for precomputing address of contract that is going to be deployed in the network.

To construct it, you need the account and Web3 object with the integrated zksync module.

from zksync2.manage_contracts.nonce_holder import NonceHolder
from eth_account import Account
from eth_account.signers.local import LocalAccount
from zksync2.module.module_builder import ZkSyncBuilder

zksync_web3 = ZkSyncBuilder.build("ZKSYNC_NETWORK_URL")
account: LocalAccount = Account.from_key("PRIVATE_KEY")
nonce_holder = NonceHolder(zksync_web3, account)

Methods:

Method	Parameters	Return value	Description
get_account_nonce	-	Nonce	Returns account nonce.
get_deployment_nonce	-	Nonce	Return the current deployment nonce that is going to be used.
increment_deployment_nonce	Address	Nothing	Manually increments deployment nonce by the provided account address.

ERC20Contract

This is a system contract that is used internally as a part of the implementation methods of EthereumProvider

A more interesting type includes the ERC20FunctionEncoder. It's used to provide method encoding in the case of sending non-native tokens inside the network.

Construction needs only Web3 object with appended zksync module(ZkSyncBuilder)

It has only 1 single method: python encode_method with arguments of function name, and its args

ContractDeployer

ContractDeployer is a utility system contract, represented as a type to cover the following functionality:

• encode binary contract representation by create method for further deploying.
• encode binary contract representation by create2 method for further deploying.
• Precompute contract address for create and create2 methods.

Construction: needs only web3 object with appended zksync module

Example:

from zksync2.manage_contracts.contract_deployer import ContractDeployer
from zksync2.module.module_builder import ZkSyncBuilder

zksync_web3 = ZkSyncBuilder.build("ZKSYNC_NETWORK_URL")
deployer = ContractDeployer(zksync_web3)

Parameter and Methods:

Method	Parameters	Return value	Description
encode_create	bytecode, optional call_data & salt	HexStr	Creates binary representation of a contract in an internal deploying format. bytecode - contract binary representation, call_data is used for ctor bytecode only, salt is used to generate unique identifier of deploying contract.
encode_create2	bytecode, optional call_data & salt	HexStr	Creates binary representation of contract in an internal deploying format. bytecode - contract binary representation, call_data is used for ctor bytecode only, salt is used to generate unique identifier of deploying contract.
compute_l2_create_address	Address, Nonce	Address	Accepts address of deployer and current deployed nonce and returns address of contract that is going to be deployed by theencode_create method.
compute_l2_create2_address	Address, bytecode, ctor bytecode, salt	Address	Accepts address of the deployer, binary representation of contract, its constructor in binary format and salt. By default constructor can be b'0' value. It returns the address of the contract that is going to be deployed by anencode_create2 method.