use_bls_wallet_clients.md

Use BLS Wallet Client

This walkthrough will show you how to submit an ERC20 transfer to the BLS Wallet Aggregator.

Add bls-wallet-clients

# npm
npm install bls-wallet-clients
# yarn
yarn add bls-wallet-clients
# deno in example further below

Import

import { providers } from "ethers";
import { Aggregator, BlsWalletWrapper, getConfig } from "bls-wallet-clients";

Deno

You can use esm.sh or a similar service to get Deno compatible modules.

import { providers } from "https://esm.sh/ethers@latest";
import { Aggregator, BlsWalletWrapper, getConfig } from "https://esm.sh/bls-wallet-clients@latest";

Get Deployed Contract Addresses

You can find current contract deployments in the contracts networks folder. If you would like to deploy locally, see Local development. If you would like to deploy to a remote network, see Remote development.

Send a transaction

import { readFile } from 'fs/promises';

// import fetch from 'node-fetch'; // Add this if using nodejs<18
import { ethers, providers } from 'ethers';
import { Aggregator, BlsWalletWrapper, getConfig } from 'bls-wallet-clients';

// globalThis.fetch = fetch; // Add this if using nodejs<18

// Instantiate a provider via browser extension, such as Metamask 
// const provider = new providers.Web3Provider(window.ethereum);
// Or via RPC
const provider = new providers.JsonRpcProvider('https://goerli-rollup.arbitrum.io/rpc');
// See https://docs.ethers.io/v5/getting-started/ for more options

// Get the deployed contract addresses for the network.
// Here, we will get the Arbitrum testnet.
// See local_development.md for deploying locally and
// remote_development.md for deploying to a remote network.
const netCfg = await getConfig(
  '../contracts/networks/arbitrum-goerli.json',
  async (path) => readFile(path),
);

// 32 random bytes
const privateKey = '0x0001020304050607080910111213141516171819202122232425262728293031';

// Note that if a wallet doesn't yet exist, it will be
// lazily created on the first transaction.
const wallet = await BlsWalletWrapper.connect(
  privateKey,
  netCfg.addresses.verificationGateway,
  provider
);

const erc20Address = netCfg.addresses.testToken; // Or some other ERC20 token
const erc20Abi = [
    'function mint(address to, uint amount) returns (bool)',
];
const erc20 = new ethers.Contract(erc20Address, erc20Abi, provider);

console.log('Contract wallet:', wallet.address);
console.log('Test token:', erc20.address);

const nonce = await wallet.Nonce();
// All of the actions in a bundle are atomic, if one
// action fails they will all fail.
const bundle = wallet.sign({
  nonce,
  actions: [
    {
      // Mint ourselves one test token
      ethValue: 0,
      contractAddress: erc20.address,
      encodedFunction: erc20.interface.encodeFunctionData(
        'mint',
        [wallet.address, ethers.utils.parseUnits('1', 18)],
      ),
    },
  ],
});

const aggregator = new Aggregator('https://arbitrum-goerli.blswallet.org');

console.log('Sending bundle to the aggregator');
const addResult = await aggregator.add(bundle);

if ('failures' in addResult) {
  throw new Error(addResult.failures.join('\n'));
}

console.log('Bundle hash:', addResult.hash);

const checkConfirmation = async () => {
  console.log('Checking for confirmation')
  const maybeReceipt = await aggregator.lookupReceipt(addResult.hash);

  if (maybeReceipt === undefined) {
    return;
  }

  console.log('Confirmed in block', maybeReceipt.blockNumber);
  provider.off('block', checkConfirmation);
};

provider.on('block', checkConfirmation);

More

See clients for additional functionality.