Integration

Smart Accounts are created deterministically using the CREATE2 opcode, meaning the smart account address can be identified even before it is deployed. It will also maintain the same address across different chains.

To integrate a Biconomy Smart Account, you'll need the bundler url. If you also want to use the paymaster, you'll need Paymaster api key.

Installation

First, install the following packages for initializing the Smart Account.

npm

npm install @biconomy/account

yarn

yarn add @biconomy/account

pnpm

pnpm add @biconomy/account

Integration

Specify PRIVATE_KEY, BUNDLER_URL, and RPC_URL (for ethers) to create a smart account.

Viem

import { Hex, createWalletClient, http } from "viem";
import { privateKeyToAccount } from "viem/accounts";
import { polygonAmoy } from "viem/chains";
import { createSmartAccountClient } from "@biconomy/account";

// ----- 1. Generate EOA from private key
const account = privateKeyToAccount("0x" + "PRIVATE_KEY");
const client = createWalletClient({
  account,
  chain: polygonAmoy,
  transport: http(),
});
const eoa = client.account.address;
console.log(`EOA address: ${eoa}`);

// ------ 2. Create biconomy smart account instance
const smartAccount = await createSmartAccountClient({
  signer: client,
  bundlerUrl: "", // <-- Read about this at https://legacy-docs.biconomy.io/dashboard#bundler-url
  biconomyPaymasterApiKey: "", // <-- Read about at https://legacy-docs.biconomy.io/dashboard/paymaster
});
const smartAccountAddress = await smartAccount.getAccountAddress();
console.log("Smart Account Address", smartAccountAddress);

Ethers

import { ethers } from "ethers";
import { createSmartAccountClient } from "@biconomy/account";

let provider = new ethers.JsonRpcProvider("RPC_URL");
let signer = new ethers.Wallet("PRIVATE_KEY", provider);

const biconomySmartAccountConfig = {
  signer: signer,
  bundlerUrl: "", // <-- Read about this at https://legacy-docs.biconomy.io/dashboard#bundler-url
  biconomyPaymasterApiKey: "", // <-- Read about at https://legacy-docs.biconomy.io/dashboard/paymaster
};

const smartAccount = await createSmartAccountClient(biconomySmartAccountConfig);

const smartAccountAddress = await smartAccount.getAccountAddress();
console.log("Smart Account Address", smartAccountAddress);

Alchemy

import { ethers } from "ethers";
import { polygonAmoy } from "viem/chains";
import { createSmartAccountClient } from "@biconomy/account";
import { WalletClientSigner } from "@alchemy/aa-core";

const account = privateKeyToAccount("0x" + "PRIVATE_KEY");
const client = createWalletClient({
  account,
  chain: polygonAmoy,
  transport: http(),
});
const alchemySigner = new WalletClientSigner(client, "json-rpc");
const smartAccount = await createSmartAccountClient({
  signer: alchemySigner,
  bundlerUrl: config.bundlerUrl,
  biconomyPaymasterApiKey: config.biconomyPaymasterApiKey,
});
const saAddress = await smartAccount.getAccountAddress();
console.log("SA Address", saAddress);

In this doc, the following values are used by default:

• ECDSA Validation Module. Other validation modules can be enabled based on the specific use case.
• The default entry point address is used for the chainId.
• An index with a value 0, but you can also specify a custom index value in the configuration to generate multiple smart accounts with the same signer.

CREATE2 allows us to enable flows where users could even send funds to an undeployed wallet, which could then be used to pay for the gas for deployment. A smart account will be deployed with the first UserOp execution.