Generate a multisig signature

The Smart Accounts Kit supports Multisig smart accounts, allowing you to add multiple externally owned accounts (EOA) signers with a configurable execution threshold. When the threshold is greater than 1, you can collect signatures from the required signers and use the aggregateSignature function to combine them into a single aggregated signature.

Prerequisites

• Install and set up the Smart Accounts Kit.
• Create a Multisig smart account.

Generate a multisig signature

The following example configures a Multisig smart account with two different signers: Alice and Bob. The account has a threshold of 2, meaning that signatures from both parties are required for any execution.

• example.ts
• config.ts

import {
  bundlerClient,
  aliceSmartAccount,
  bobSmartAccount,
  aliceAccount,
  bobAccount,
} from './config.ts'
import { aggregateSignature } from '@metamask/smart-accounts-kit'

const userOperation = await bundlerClient.prepareUserOperation({
  account: aliceSmartAccount,
  calls: [
    {
      target: zeroAddress,
      value: 0n,
      data: '0x',
    },
  ],
})

const aliceSignature = await aliceSmartAccount.signUserOperation(userOperation)
const bobSignature = await bobSmartAccount.signUserOperation(userOperation)

const aggregatedSignature = aggregateSignature({
  signatures: [
    {
      signer: aliceAccount.address,
      signature: aliceSignature,
      type: 'ECDSA',
    },
    {
      signer: bobAccount.address,
      signature: bobSignature,
      type: 'ECDSA',
    },
  ],
})

import { createPublicClient, http } from 'viem'
import { generatePrivateKey, privateKeyToAccount } from 'viem/accounts'
import { createBundlerClient } from 'viem/account-abstraction'
import { sepolia as chain } from 'viem/chains'
import { Implementation, toMetaMaskSmartAccount } from '@metamask/smart-accounts-kit'

const publicClient = createPublicClient({
  chain,
  transport: http(),
})

const alicePrivateKey = generatePrivateKey()
export const aliceAccount = privateKeyToAccount(alicePrivateKey)

const bobPrivateKey = generatePrivateKey()
export const bobAccount = privateKeyToAccount(bobPrivateKey)

const signers = [aliceAccount.address, bobAccount.address]
const threshold = 2n

export const aliceSmartAccount = await toMetaMaskSmartAccount({
  client: publicClient,
  implementation: Implementation.MultiSig,
  deployParams: [signers, threshold],
  deploySalt: '0x',
  signer: [{ account: aliceAccount }],
})

export const bobSmartAccount = await toMetaMaskSmartAccount({
  client: publicClient,
  implementation: Implementation.MultiSig,
  deployParams: [signers, threshold],
  deploySalt: '0x',
  signer: [{ account: bobAccount }],
})

export const bundlerClient = createBundlerClient({
  client: publicClient,
  transport: http('https://public.pimlico.io/v2/rpc'),
})