# Dart SDK
This section contains documentation for the Dart SDK for zkSync.
This is the alpha version of the SDK, if you find mistakes - you can contact us on Discord.
This is an unofficial open-sourced SDK for zkSync. Link to GitHub repo. (opens new window)
Kudos to Vareger (opens new window) for developing it!
# Table of Contents
- Dart SDK
# Getting Started
- Connect to the zkSync network.
- Deposit assets from Ethereum into zkSync.
- Make transfers.
- Withdraw funds back to Ethereum mainnet (or testnet).
# Adding dependencies
Using this SDK requires precompiled binary of zkSync cryptography implementation. Please download directly from official repo (opens new window)
Then just add this sdk as a dependency into your app build configuration.
name: <your_app_name> ... environment: sdk: '>=2.10.0 <3.0.0' dependencies: zksync: ^0.0.1 ...
Native library is precompiled for the following platforms:
- Linux x86_64
- OSX x86_64 (MacOS 11 BigSur included)
- Windows x86_64
Client library is divided into three separate packages. Just add required into
imports block of your main file:
import 'package:zksync/client.dart'; // ZkSync RPC/REST client import 'package:zksync/credentials.dart'; // Crypto Credentials import 'package:zksync/zksync.dart'; // Main Wallet
# Creating signers
All messages in zkSync network must be signed by the private key. There are two keys required: Level 1 (L1) for Ethereum and Level 2 (L2) for zkSync network.
To operate in zkSync network you need to create
ZkSigner instance first. There are few ways to create it:
Using seed bytes (like MNEMONIC phrase) with the length >= 32
final zkSigner = ZksSigner.seed(SEED);
Using raw private key
final rawPrivateKey = hex.decode('0x...'); final zkSigner = ZksSigner.raw(rawPrivateKey);
Using raw private key in hex
final zkSigner = ZksSigner.hex('0x...');
Using EthSigner (explained below). The private key used by ZkSigner is implicitly derived by signing a special message with Ethereum L1 key
final ethSigner = ...; final zkSigner = await ZksSigher.fromEthSigner(ethSigner, ChainId.Goerli);
To interract with Ethereum L1 chain (to make a
Withdraw funds), you'll need
EthSigner instance. It can
be instantiated in several different ways:
Using raw private key in hex
final ethSigner = EthSigner.hex(privateKey, chainId: ChainId.Goerli.getChainId());
Using raw private key
final rawPrivateKey = hex.decode('0x...'); final ethSigner = EthSigner.raw(privateKey);
Credentials from Web3dart
import 'package:web3dart/web3dart.dart' as web3;
final credentials = web3.EthPrivateKey.fromHex(hexKey);
# Connecting to zkSync network
In order to interact with both zkSync and Ethereum networks you'll need to create providers and provide endpoints to blockchain nodes.
# zkSync client
This SDK has predefined URLs for the following networks
ChainId.Goerli that are
officially supported by MatterLabs. Also you can use local node for testing
ChainId.Localhost or simply set endpoint
final zksync = ZkSyncClient.fromChainId(ChainId.Goerli);
You can also create
ZkSyncClient with any custom endpoint URL
final zksync = ZkSyncClient('http://localhost:3030', Client());
# Ethereum client
For onchain operations in Ethereum network you can use
final ethSigner = ...; final ethereum = EthereumClient('http://localhost:8545', ethSigner.credentials, ChainId.Goerli);
# Creating a Wallet
To control and operate with your account in zkSync you can use the
Wallet. It can sign transactions with the key
EthSigner, then send signed transactions into zkSync network using
final ethSigner = ...; final zkSigner = ...; final ethClient = ...; final zksClient = ...; final wallet = Wallet(zksClient, ethClient, zkSigner, ethSigner);
# Depositing assets from Ethereum into zkSync
In order to deposit assets from Ethereum network into zkSync please use the following sequence:
final ethSigner = ...; final ethClient = ...; final receiver = await ethSigner.extractAddress(); final depositTx = await ethClient.deposit(Token.eth, EtherAmount.fromUnitAndValue(EtherUnit.ether, 1).getInWei, receiver);
# Checking your zkSync balance
In order to check your account balance in zkSync network please use the following commands:
final wallet = ...; final state = await wallet.getState(); final balance = state.commited.balances['ETH'];
# Unlocking zkSync account
In order to make any transactions in zkSync network, you'll need to register your ZkSigner's public key first. Please use the following command to do this:
final zkSigner = ...; final wallet = ...; final authTx = await wallet.setSigningKey( ZksPubkeyHash.fromHex(zkSigner.publicKeyHash), token: Token.eth); print(authTx);
# Transfering funds in zkSync
Deposited and account
Unlocked, you can transfer funds inside zkSync network.
Please note, that it is possible to send assets within zkSync to any Ethereum address, without preliminary registration in zkSync!
In the example below, we're going to transfer 0.1 ETH
final wallet = ...; final receiver = EthereumAddress.fromHex('0x...'); final tx = await wallet.transfer( receiver, EtherAmount.fromUnitAndValue(EtherUnit.eth, 0.1).getInWei, token: Token.eth); print(tx);
# Withdrawing funds back to Ethereum
All your funds can be withdrawn back to any yours account in Ethereum. Please use the following commands:
final wallet = ...; final withdrawTx = await wallet.withdraw( receiver, EtherAmount.fromUnitAndValue(EtherUnit.eth, 0.5).getInWei, token: Token.eth); print(withdrawTx);
Assets will be withdrawn to the target address after a zero-knowledge proof of zkSync block with this operation is generated and verified by the mainnet contract (which usually takes about 2-10 min).
# Forced and Full exit
Also you can force full withdrawal of all your funds back to your onchain account with a single command:
final wallet = ...; final exitTx = await wallet.forcedExit(receiver, token: Token.eth); print(exitTx);
On Ethereum (onchain)
final ethClient = ...; final wallet = ...; final exitTx = await ethClient.fullExit(Token.eth, await wallet.getAccountId()); print(exitTx);