⛽Holdstation Gas Station

Holdstation offers a free service to support all dApps looking to integrate zkSync Paymaster! It's our way of helping the zkSync community thrive together!

Account Abstraction, a core technology that enriches user-friendly experiences and security, is at the heart of what we do at Holdstation. We share a similar vision with Vitalik and are here to support growth together.

With the zkSync account abstraction paymaster, Holdstation empowers all dApps to pay gas using any tokens available, making transactions smoother and more user-friendly.

The gas price depends on the gas estimation in ETH, and can be paid by:

1. USDT

2. USDC

3. dApp token (we can support)

How to Integrate with Holdstation Gas Station?

Follow our Paymaster Contract Address: 0x8a71416F2BCBd428c3Fc4284404617B139C0181C

Kindly note the following code is our sample. We encourage you to reach out to our dedicated Dev team for assistance. Your seamless integration is our priority!

Paymaster sample for EOA Wallet

//// PAYMASTER with EOA Wallet

import { Contract, Provider, types, utils, Wallet } from 'zksync-web3';
import { ethers } from 'ethers';

const PAYMASTER_ADDRESS = '0x8a71416F2BCBd428c3Fc4284404617B139C0181C'
const provider = new Provider(RPC_URL);
const signer = new Wallet(PRIVATE_KEY, provider);
const contract = new Contract(CONTRACT_ADDRESS, CONTRACT_ABI, provider)

// method: approve, swap
// ACCOUNT: public address
const populateContract = await contract.populateTransaction[method](...params, {
      from: ACCOUNT,
});

const gasLimit = await provider.estimateGas({ ...populatedTx, from: ACCOUNT });
const gasPrice = await provider.getGasPrice();


// TOKEN_ADDRESS: token pay gas erc20
const paymasterParams = utils.getPaymasterParams(PAYMASTER_ADDRESS, {
  type: "ApprovalBased",
  TOKEN_ADDRESS,
  minimalAllowance: ethers.BigNumber.from(1),,
  innerInput: new Uint8Array(),
});

populatedTx.customData = {
  gasPerPubdata: utils.DEFAULT_GAS_PER_PUBDATA_LIMIT
  paymasterParams,
};

const sentTx = await signer.sendTransaction({
  ...populatedTx,
  maxFeePerGas: gasPrice,
  maxPriorityFeePerGas: BigNumber.from(0),
  gasLimit,
});

Paymaster sample for Account Abstraction Wallet

//// PAYMASTER with AA Wallet

import { Contract, Provider, types, utils, Wallet } from 'zksync-web3';
import { ethers } from 'ethers';

const PAYMASTER_ADDRESS = '0x8a71416F2BCBd428c3Fc4284404617B139C0181C'

const provider = new Provider(RPC_URL);
const signer = new Wallet(PRIVATE_KEY, provider);
const contract = new Contract(CONTRACT_ADDRESS, CONTRACT_ABI, provider)

// method: approve,swap
// ACCOUNT: public address
const populateContract = await contract.populateTransaction[method](...params, {
      from: ACCOUNT,
});

const gasLimit = await provider.estimateGas({ ...populatedTx, from: ACCOUNT });

const paymasterParams = utils.getPaymasterParams(PAYMASTER_ADDRESS, {
  type: "ApprovalBased",
  TOKEN_ADDRESS,
  minimalAllowance: ethers.BigNumber.from(1),
  innerInput: new Uint8Array(),
});

populatedTx.customData = {
  ...populatedTx.customData,
  paymasterParams: paramsPaymaster,
};

populatedTx.gasLimit = gasLimit;
populatedTx.maxFeePerGas = await provider.getGasPrice();
populatedTx.maxPriorityFeePerGas = ethers.BigNumber.from(0);
populatedTx.chainId = parseInt(CHAIN_ID);
populatedTx.from = ACCOUNT;
populatedTx.nonce = await provider.getTransactionCount(ACCOUNT);
populatedTx.type = 113;
populatedTx.value = ethers.BigNumber.from(0);
populatedTx.customData = {
  ...populatedTx.customData,
  gasPerPubdata: utils.DEFAULT_GAS_PER_PUBDATA_LIMIT,
} as types.Eip712Meta;

const signature = ethers.utils.arrayify(ethers.utils.joinSignature(await signer.eip712.sign(populatedTx)));
populatedTx.customData = {
  ...populatedTx.customData,
  customSignature: signature,
};

const sendTx = await provider.sendTransaction(utils.serialize(populatedTx));