🚀 zksync2-java Java SDK 🚀

In order to provide easy access to all the features of ZKsync Era, the zksync2-java Java SDK was created, which is made in a way that has an interface very similar to those of web3j. In fact, web3j is a peer dependency of our library and most of the objects exported by zksync2-java inherit from the corresponding web3j objects and override only the fields that need to be changed.

While most of the existing SDKs functionalities should work out of the box, deploying smart contracts or using unique ZKsync Era features, like account abstraction, requires providing additional fields to those that Ethereum transactions have by default.

The library is made in such a way that after replacing web3j with zksync2-java most client apps will work out of box.

🔗 For a detailed walkthrough, refer to the official documentation.

Dependency

For connecting zksync2 library just add the following dependency to your build file.

Maven pom.xml

<project>
  ...
  <dependencies>
    <dependency>
      <groupId>io.zksync</groupId>
      <artifactId>zksync2</artifactId>
      <version>v0.2.0</version>
    </dependency>
  </dependencies>
</project>

Gradle build.gradle

dependencies {
    implementation "io.zksync:zksync2:v0.2.0"
}

📝 Examples

The complete examples with various use cases are available here.

Connect to the ZKsync Era network:

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("http://127.0.0.1:3050"));
    }
}

Create a wallet

import com.sun.net.httpserver.HttpServer;
import io.zksync.crypto.signer.EthSigner;
import io.zksync.protocol.ZkSync;
import io.zksync.protocol.core.Token;
import io.zksync.protocol.account.wallet;

public class Main {
    public static void main(String... args) {
        ZkSync zksync = ZkSync.build(new HttpService("https://sepolia.era.zksync.dev"));
        Credentials credentials = Credentials.create("PRIVATE_KEY");
        Web3j l1Web3 = Web3j.build(new HttpService("https://rpc.ankr.com/eth_sepolia"));

        Wallet wallet = new Wallet(l1Web3, zksync, credentials);
    }
}

Check account balances

BigInteger ethBalance = wallet.getBalance().send(); // balance on ZKsync Era network

BigInteger ethBalanceL1 = wallet.getBalanceL1().send(); // balance on Sepolia network

Transfer funds

Transfer funds among accounts on L2 network.

TransferTransaction transaction = new TransferTransaction("RECEIVER", amount, signer.getAddress());
TransactionReceipt receipt = testWallet.transfer(transaction).sendAsync().join();

Deposit funds

Transfer funds from L1 to L2 network.

DepositTransaction transaction = new DepositTransaction(ZkSyncAddresses.ETH_ADDRESS, amount);
String hash = testWallet.deposit(transaction).sendAsync().join().getResult();

Withdraw funds

Transfer funds from L2 to L1 network.

WithdrawTransaction transaction = new WithdrawTransaction(ZkSyncAddresses.ETH_ADDRESS, amount, testWallet.getAddress());
TransactionReceipt result = testWallet.withdraw(transaction).sendAsync().join();

🤖 Running tests

In order to run test you need to run local-setup on your machine. For running tests, use:

gradle clean test

🤝 Contributing

We welcome contributions from the community! If you're interested in contributing to the zksync2-java Java SDK, please take a look at our CONTRIBUTING.md for guidelines and details on the process.

Thank you for making zksync2-java Java SDK better! 🙌