USDCBridge - ZKsync Docs

USDCBridge class implements AbstractBridge class and provides methods for depositing and withdrawing USDC tokens using custom USDC bridge.

`constructor(wallet: Wallet)`

Creates a USDCBridge object.

Parameters:

Parameter	Type	Description
`wallet`	`Wallet`	ZKsync wallet instance.

Example:

import { Provider, types, Wallet, USDCBridge } from 'zksync-ethers';
import { ethers } from 'ethers';

const PRIVATE_KEY = process.env.WALLET_PRIVATE_KEY || '0x<WALLET_PRIVATE_KEY>';
const provider = Provider.getDefaultProvider(types.Network.Sepolia);
const ethProvider = ethers.getDefaultProvider('sepolia');
const wallet = new Wallet(PRIVATE_KEY, provider, ethProvider);

const usdcBridge = new USDCBridge(wallet);
console.log('USDC Bridge initialized', usdcBridge);

`deposit`

Deposits USDC tokens using the custom USDC bridge

Inputs

Parameter	Type	Description
`transaction`	`IDepositTransaction`	Deposit transaction.

async deposit(transaction: IDepositTransaction): Promise<PriorityOpResponse>

Example

import { Wallet, Provider, types, USDCBridge } from 'zksync-ethers';
import { ethers } from 'ethers';

const PRIVATE_KEY = process.env.WALLET_PRIVATE_KEY || '0x<WALLET_PRIVATE_KEY>';
const USDC_TOKEN_L1_ADDRESS = '<USDC_TOKEN_ADDRESS>';
const USDC_BRIDGE_L1_ADDRESS = '<USDC_BRIDGE_L1_ADDRESS>';
const AMOUNT = '5';

const provider = Provider.getDefaultProvider(types.Network.Sepolia);
const ethProvider = ethers.getDefaultProvider('sepolia');
const wallet = new Wallet(PRIVATE_KEY, provider, ethProvider);
const usdcBridge = new USDCBridge(wallet);

async function main() {
  const depositTx = await usdcBridge.deposit({
    token: USDC_TOKEN_L1_ADDRESS,
    amount: ethers.parseUnits(AMOUNT, 6),
    approveERC20: true,
    bridgeAddress: USDC_BRIDGE_L1_ADDRESS,
  });

  // Note that we wait not only for the L1 transaction to complete but also for it to be
  // processed by ZKsync. If we want to wait only for the transaction to be processed on L1,
  // we can use `await depositTx.waitL1Commit()`
  await depositTx.wait();
}

`withdraw`

Withdraws USDC tokens using the custom USDC bridge from the associated account on L2 network to the target account on L1 network.

Inputs

Parameter	Type	Description
`transaction`	`IWithdrawTransaction`	Withdraw transaction.

async withdraw(transaction: IWithdrawTransaction): Promise<TransactionResponse>

Examples

import { Wallet, Provider, types, USDCBridge } from 'zksync-ethers';
import { ethers } from 'ethers';

const PRIVATE_KEY = process.env.WALLET_PRIVATE_KEY || '0x<WALLET_PRIVATE_KEY>';
const USDC_TOKEN_L2_ADDRESS = '<USDC_TOKEN_L2_ADDRESS>';
const USDC_BRIDGE_L2_ADDRESS = '<USDC_BRIDGE_L2_ADDRESS>';
const AMOUNT = '5';

const provider = Provider.getDefaultProvider(types.Network.Sepolia);
const wallet = new Wallet(PRIVATE_KEY, provider);
const usdcBridge = new USDCBridge(wallet);

async function main() {
  const withdrawTx = await usdcBridge.withdraw({
    token: USDC_TOKEN_L2_ADDRESS,
    amount: ethers.parseUnits(AMOUNT, 6),
    bridgeAddress: USDC_BRIDGE_L2_ADDRESS,
    approveERC20: true,
  });
  console.log('Withdraw transaction hash:', withdrawTx.hash);
}

`finalizeWithdrawal`

Proves the inclusion of the L2 -> L1 withdrawal message.

Inputs

Parameter	Type	Description
`bridgeAddress`	`Address`	The address of the USDC bridge contract to be used.
`withdrawalHash`	`BytesLike`	Hash of the L2 transaction where the withdrawal was initiated.
`index?`	`number`	In case there were multiple withdrawals in one transaction, you may pass an index of the withdrawal you want to finalize. Defaults to 0.
`overrides?`	`ethers.Overrides`	Transaction's overrides which may be used to pass L1 `gasLimit`, `gasPrice`, `value`, etc.

async finalizeWithdrawal(
  bridgeAddress: Address,
  withdrawalHash: BytesLike,
  index: number = 0,
  overrides?: ethers.Overrides
): Promise<ethers.ContractTransactionResponse>

Example

import { Wallet, Provider, types, USDCBridge } from 'zksync-ethers';
import { ethers } from 'ethers';

const PRIVATE_KEY = process.env.WALLET_PRIVATE_KEY || '0x<WALLET_PRIVATE_KEY>';
const USDC_BRIDGE_L1_ADDRESS = '<USDC_BRIDGE_L1_ADDRESS>';

const provider = Provider.getDefaultProvider(types.Network.Sepolia);
const ethProvider = ethers.getDefaultProvider('sepolia');
const wallet = new Wallet(PRIVATE_KEY, provider, ethProvider);
const usdcBridge = new USDCBridge(wallet);

const WITHDRAWAL_TX_HASH = '<WITHDRAWAL_TX_HASH>';

async function finalizeWithdrawal() {
  const finalizeWithdrawalTx = await usdcBridge.finalizeWithdrawal(USDC_BRIDGE_L1_ADDRESS, WITHDRAWAL_TX_HASH);
  console.log('Finalize withdrawal transaction hash:', finalizeWithdrawalTx.hash);
}

`isWithdrawalFinalized`

Returns whether the withdrawal transaction has been finalized on the L1 network.

Inputs

Parameter	Type	Description
`bridgeAddress`	`Address`	The address of the USDC bridge contract to be used.
`withdrawalHash`	`BytesLike`	Hash of the L2 transaction where the withdrawal was initiated.
`index?`	`number`	In case there were multiple withdrawals in one transaction, you may pass an index of the withdrawal you want to finalize. Defaults to 0.

async isWithdrawalFinalized(
  bridgeAddress: Address,
  withdrawalHash: BytesLike,
  index: number = 0
): Promise<boolean>

Example

import { Wallet, Provider, types, USDCBridge } from 'zksync-ethers';
import { ethers } from 'ethers';

const PRIVATE_KEY = process.env.WALLET_PRIVATE_KEY || '0x<WALLET_PRIVATE_KEY>';
const USDC_BRIDGE_L1_ADDRESS = '<USDC_BRIDGE_L1_ADDRESS>';

const provider = Provider.getDefaultProvider(types.Network.Sepolia);
const ethProvider = ethers.getDefaultProvider('sepolia');
const wallet = new Wallet(PRIVATE_KEY, provider, ethProvider);
const usdcBridge = new USDCBridge(wallet);

const WITHDRAWAL_TX_HASH = '<WITHDRAWAL_TX_HASH>';

async function checkWithdrawalStatus() {
  const isFinalized = await usdcBridge.isWithdrawalFinalized(USDC_BRIDGE_L1_ADDRESS, WITHDRAWAL_TX_HASH);
  console.log('Withdrawal is finalized:', isFinalized);
}

AbstractBridge

An abstract class that provides a skeleton implementation for bridging assets.

Types

Types used by bridge classes.