Providers

A Web3 Provider object provides application-layer access to underlying blockchain networks.

The zksync2-java library supports provider methods from the web3j library and supplies additional functionality.

ZkSync: Supplies the same functionality as Web3 and extends it with zkSync-specific methods.

ZkSync

Info

• This doc details zkSync Era specific methods.
• Web3Swift implementations link to their docs.

constructor

Returns a ZkSyncClient object.

Inputs

Parameter	Type	Description
providerURL	URL	Network RPC URL (optional).

Example

import io.zksync.protocol.ZkSync;
import org.web3j.protocol.http.HttpService;

public class Main {
    public static void main(String ...args) {
        ZkSync zksync = ZkSync.build(new HttpService("https://sepolia.era.zksync.dev"));
    }
}

estimateFee

Returns an estimated ZksEstimateFee for requested transaction.

Inputs

Parameter	Type	Description
transaction	Transaction	Transaction request.

import io.zksync.protocol.ZkSync;
import org.web3j.protocol.http.HttpService;
import io.zksync.methods.response.ZkTransactionReceipt;

public class Main {
    public static void main(String ...args) {
      io.zksync.methods.request.Transaction estimate = io.zksync.methods.request.Transaction.createFunctionCallTransaction(
                "0x7e5f4552091a69125d5dfcb7b8c2659029395bdf",
                "0x7e5f4552091a69125d5dfcb7b8c2659029395bdf",
                BigInteger.ZERO,
                BigInteger.ZERO,
                "0x"
        );

      Fee fee = zksync.zksEstimateFee(estimate).send().getResult();
    }

estimateGas

Returns an estimate of the amount of gas required to submit a transaction to the network.

Inputs

Parameter	Type	Description
transaction	Transaction	Transaction class.

Example

import io.zksync.protocol.ZkSync;
import org.web3j.protocol.http.HttpService;
import io.zksync.methods.response.ZkTransactionReceipt;

public class Main {
    public static void main(String ...args) {
      io.zksync.methods.request.Transaction estimate = io.zksync.methods.request.Transaction.createFunctionCallTransaction(
                "0x7e5f4552091a69125d5dfcb7b8c2659029395bdf",
                "0x7e5f4552091a69125d5dfcb7b8c2659029395bdf",
                BigInteger.ZERO,
                BigInteger.ZERO,
                "0x"
        );

      BigInteger gasUsed = zksync.ethEstimateGas(estimate).send().getAmountUsed();
    }
}

estimateGasL1

Returns an estimate of the amount of gas required to submit a transaction from L1 to L2 as a EthEstimateGas object.

Calls the zks_estimateL1ToL2 JSON-RPC method.

Inputs

Parameter	Type	Description
transaction	Transaction	Transaction class.

Example

import io.zksync.protocol.ZkSync;
import org.web3j.protocol.http.HttpService;
import io.zksync.methods.response.ZkTransactionReceipt;

public class Main {
    public static void main(String ...args) {
      io.zksync.methods.request.Transaction estimate = io.zksync.methods.request.Transaction.createFunctionCallTransaction(
                "0x7e5f4552091a69125d5dfcb7b8c2659029395bdf",
                "0x7e5f4552091a69125d5dfcb7b8c2659029395bdf",
                BigInteger.ZERO,
                BigInteger.ZERO,
                "0x"
        );

      BigInteger estimatedGas = zksync.estimateGasL1(estimate).send().getAmountUsed();
    }
}

estimateL1ToL2Execute

Returns gas estimation for an L1 to L2 execute operation.

Inputs

Parameter	Type	Description
contractAddress	String	Address of contract.
calldata	byte[]	The transaction call data.
caller	String	Caller address.
l2GasLimit	BigInteger	Current L2 gas value (optional).
l2Value	BigInteger	L2 amount (optional).
factoryDeps	byte[][]	Factory deps (optional).
operatorTip	BigInteger	Operator tip (optional).
gasPerPubdataByte?	BigInteger	Constant representing current amount of gas per byte (optional).
refoundRecepient	String	Refound address.

Example

import io.zksync.protocol.ZkSync;
import org.web3j.protocol.http.HttpService;
import io.zksync.methods.response.ZkTransactionReceipt;

public class Main {
    public static void main(String ...args) {
      String mainContractAddress = zksync.zksMainContract().sendAsync().join()

      BigInteger estimatedGas = zksync.estimateGasL1(mainContractAddress, Numeric.hexStringToByteArray("0x"), "0x36615Cf349d7F6344891B1e7CA7C72883F5dc049", null, BigInteger.
      valueOf(7_000_000_000L), null, null, null, null).
      send().
      getAmountUsed();
    }
}

allAccountBalances

Returns all balances for confirmed tokens given by an account address.

Calls the zks_getAllAccountBalances JSON-RPC method.

Inputs

Parameter	Type	Description
address	String	Account address.

Example

import io.zksync.protocol.ZkSync;
import org.web3j.protocol.http.HttpService;
import io.zksync.methods.response.ZkTransactionReceipt;

public class Main {
    public static void main(String ...args) {
      ZksAccountBalances allBalances = zkSync.zksGetAllAccountBalances("0x36615Cf349d7F6344891B1e7CA7C72883F5dc049").send();
    }
}

getBlockDetails

Returns additional zkSync-specific information about the L2 block.

Calls the zks_getBlockDetails JSON-RPC method.

Inputs

Parameter	Type	Description
blockNumber	BigInteger	Block number.

Example

import io.zksync.protocol.ZkSync;
import org.web3j.protocol.http.HttpService;
import io.zksync.methods.response.ZkTransactionReceipt;

public class Main {
    public static void main(String ...args) {
      ZksBlockDetails blockDetails = zkSync.getBlockDetails(BigInteger.valueOf(90_000)).send();
    }
}

zksGetBridgeContracts

Returns the addresses of the default zkSync Era bridge contracts on both L1 and L2.

Example

import io.zksync.protocol.ZkSync;
import org.web3j.protocol.http.HttpService;
import io.zksync.methods.response.ZkTransactionReceipt;

public class Main {
    public static void main(String ...args) {
      ZksBlockDetails blockDetails = zkSync.zksGetBridgeContracts().send();
    }
}

getL1BatchBlockRange

Returns the range of blocks contained within a batch given by batch number.

Calls the zks_getL1BatchBlockRange JSON-RPC method.

Inputs

Parameter	Type	Description
l1BatchNumber	BigInteger	L1 batch number.

Example

import io.zksync.protocol.ZkSync;
import org.web3j.protocol.http.HttpService;
import io.zksync.methods.response.ZkTransactionReceipt;

public class Main {
    public static void main(String ...args) {
        BigInteger l1BatchNumber = zkSync.getL1BatchNumber().send().getL1BatchNumber();
        BlockRange blockRange = zkSync.getL1BatchBlockRange(l1BatchNumber).send().getResult();
    }
}

getL1BatchDetails

Returns data pertaining to a given batch.

Calls the zks_getL1BatchDetails JSON-RPC method.

Inputs

Parameter	Type	Description
number	BigInteger	L1 batch number.

Example

import io.zksync.protocol.ZkSync;
import org.web3j.protocol.http.HttpService;
import io.zksync.methods.response.ZkTransactionReceipt;

public class Main {
    public static void main(String ...args) {
        BigInteger l1BatchNumber = zkSync.getL1BatchNumber().send().getL1BatchNumber();
        BatchDetails blockRange = zkSync.getL1BatchBlockRange(l1BatchNumber).send().getResult();
    }
}

getL1BatchNumber

Returns the latest L1 batch number.

Calls the zks_getL1BatchNumber JSON-RPC method.

Example

import io.zksync.protocol.ZkSync;
import org.web3j.protocol.http.HttpService;
import io.zksync.methods.response.ZkTransactionReceipt;

public class Main {
    public static void main(String ...args) {
        BigInteger l1BatchNumber = zkSync.getL1BatchNumber().send().getL1BatchNumber();
    }
}

getL2ToL1LogProof

Returns the proof for a transaction's L2 to L1 log sent via the L1Messenger system contract.

Calls the zks_getL2ToL1LogProof JSON-RPC method.

Inputs

Parameter	Type	Description
txHash	String	Hash of the L2 transaction the L2 to L1 log was produced within.
index	int	The index of the L2 to L1 log in the transaction (optional).

Example

import io.zksync.protocol.ZkSync;
import org.web3j.protocol.http.HttpService;
import io.zksync.methods.response.ZkTransactionReceipt;

public class Main {
    public static void main(String ...args) {
        // Any L2 -> L1 transaction can be used.
        // In this case, withdrawal transaction is used.
        String tx = "0x2a1c6c74b184965c0cb015aae9ea134fd96215d2e4f4979cfec12563295f610e";
        L2ToL1MessageProof result = zkSync.zksGetL2ToL1LogProof(tx, 0).sendAsync().join().getResult();
    }
}

mainContract

Returns the main zkSync Era smart contract address.

Calls the zks_getMainContract JSON-RPC method.

Example

import io.zksync.protocol.ZkSync;
import org.web3j.protocol.http.HttpService;
import io.zksync.methods.response.ZkTransactionReceipt;

public class Main {
    public static void main(String ...args) {
        String result = zkSync.zksMainContract().sendAsync().join().getResult();
    }
}

zksGetTestnetPaymaster

Returns the testnet paymaster address if available, or null.

Example

import io.zksync.protocol.ZkSync;
import org.web3j.protocol.http.HttpService;
import io.zksync.methods.response.ZkTransactionReceipt;

public class Main {
    public static void main(String ...args) {
        String result = zkSync.zksGetTestnetPaymaster().sendAsync().join().getResult();
    }
}

zksGetTransactionDetails

Returns data from a specific transaction given by the transaction hash.

Calls the getTransactionDetails JSON-RPC method.

Inputs

Parameter	Type	Description
txHash	BytesLike	Transaction hash.

Example

import io.zksync.protocol.ZkSync;
import org.web3j.protocol.http.HttpService;
import io.zksync.methods.response.ZkTransactionReceipt;

public class Main {
    public static void main(String ...args) {
        TransactionDetails result = zkSync.zksGetTransactionDetails("<TX_HASH>").sendAsync().join().getResult();
    }
}

getTransferTransaction

Returns the populated transfer transaction.

Inputs

Parameter	Type	Description
tx	TransferTransaction	TransferTransaction class.
transactionManager	TransactionManager	L2 transaction manager.
gasProvider	ContractGasProvider	L2 gas provider.

Example

import io.zksync.protocol.ZkSync;
import org.web3j.protocol.http.HttpService;
import io.zksync.methods.response.ZkTransactionReceipt;

public class Main {
    public static void main(String ...args) {
        TransferTransaction transaction = new TransferTransaction(RECEIVER, amount, signer.getAddress());
        Transaction result = zkSync.getTransferTransaction(transaction, transactionManager, gasProvider).sendAsync().join().getResult();
    }
}

Retrieve populated ETH transfer transaction using paymaster to facilitate fee payment with an ERC20 token.

import io.zksync.protocol.ZkSync;
import org.web3j.protocol.http.HttpService;
import io.zksync.methods.response.ZkTransactionReceipt;

public class Main {
    public static void main(String ...args) {
        BigInteger amount = BigInteger.valueOf(7_000_000_000L);
        PaymasterParams paymasterParams = new PaymasterParams(PAYMASTER, Numeric.hexStringToByteArray(FunctionEncoder.encode(Paymaster.encodeApprovalBased(TOKEN, BigInteger.ONE, new byte[] {}))));

        TransferTransaction transaction = new TransferTransaction(RECEIVER, amount, signer.getAddress(), paymasterParams);
        Transaction result = zkSync.getTransferTransaction(transaction, transactionManager, gasProvider).sendAsync().join().getResult();
    }
}

getWithdrawTx

Returns the populated withdrawal transaction.

Inputs

Parameter	Type	Description
tx	TransferTransaction	TransferTransaction class.
transactionManager	TransactionManager	L2 transaction manager.
gasProvider	ContractGasProvider	L2 gas provider.

Examples

Retrieve populated ETH withdrawal transactions.

import io.zksync.protocol.ZkSync;
import org.web3j.protocol.http.HttpService;
import io.zksync.methods.response.ZkTransactionReceipt;

public class Main {
    public static void main(String ...args) {
        WithdrawTransaction transaction = new WithdrawTransaction(RECEIVER, amount, signer.getAddress());
        Transaction result = zkSync.getWithdrawTx(transaction, transactionManager, gasProvider).sendAsync().join().getResult();
    }
}

Retrieve populated ETH withdrawal transaction using paymaster to facilitate fee payment with an ERC20 token.

import io.zksync.protocol.ZkSync;
import org.web3j.protocol.http.HttpService;
import io.zksync.methods.response.ZkTransactionReceipt;

public class Main {
    public static void main(String ...args) {
        BigInteger amount = BigInteger.valueOf(7_000_000_000L);
        PaymasterParams paymasterParams = new PaymasterParams(PAYMASTER, Numeric.hexStringToByteArray(FunctionEncoder.encode(Paymaster.encodeApprovalBased(TOKEN, BigInteger.ONE, new byte[] {}))));

        WithdrawTransaction transaction = new WithdrawTransaction(RECEIVER, amount, signer.getAddress(), paymasterParams);
        Transaction result = zkSync.getWithdrawTx(transaction, transactionManager, gasProvider).sendAsync().join().getResult();
    }
}

l1ChainId

Returns the chain id of the underlying L1.

Calls the zks_L1ChainId JSON-RPC method.

Example

import io.zksync.protocol.ZkSync;
import org.web3j.protocol.http.HttpService;
import io.zksync.methods.response.ZkTransactionReceipt;

public class Main {
    public static void main(String ...args) {
        BigInteger result = zkSync.l1ChainId().sendAsync().join().getResult();
    }
}

l1TokenAddress

Returns the L1 token address equivalent for a L2 token address as they are not equal. ETH's address is set to zero address.

Note

Only works for tokens bridged on default zkSync Era bridges.

Inputs

Parameter	Type	Description
token	String	The address of the token on L2.

Example

import io.zksync.protocol.ZkSync;
import org.web3j.protocol.http.HttpService;
import io.zksync.methods.response.ZkTransactionReceipt;

public class Main {
    public static void main(String ...args) {
        BigInteger result = zkSync.l1ChainId().sendAsync().join().getResult();
    }
}