How to manage ownership of a Modular Account

The Multi Owner plugin lets your smart accounts have one or more ECDSA or SCA owners. This lets your account integrate with multiple signers at once, and supports recovering your account if one signer is lost.

The Multi-Owner Plugin is able to:

Update (add or remove) owners for an MSCA.
Check if an address is an owner address of an MSCA.
Show all owners of an MSCA.
Validate signed signatures of ERC-4337 enabled user operations as well as regular transactions.

All Modular Accounts have MultiOwnerPlugin pre-installed upon creation, exposing following methods for account owners to update (add or remove) and read the current owners of the account:

/// @notice Update owners of the account. Owners can update owners.
/// @param ownersToAdd The address array of owners to be added.
/// @param ownersToRemove The address array of owners to be removed.
function updateOwners(address[] memory ownersToAdd, address[] memory ownersToRemove) external;
 
/// @notice Get the owners of `account`.
/// @param account The account to get the owners of.
/// @return The addresses of the owners of the account.
function ownersOf(address account) external view returns (address[] memory);

When you connect your Modular Account to SmartAccountClient you can extend the client with multiOwnerPluginActions, which exposes a set of methods available to call the installed MultiOwnerPlugin with the client connected to the account.

1. Check if an address is one of the current owners of a Modular Account

You should first extend the SmartAccountClient connected to a Modular Account, which already comes with MultiOwnerPlugin installed upon creation, with client to multiOwnerPluginActions for the client to include the MultiOwnerPlugin actions.

Then, you can use the readOwners method of the multiOwnerPluginActions extended smart account client to check if a given address is one of the current owners of a Modular Account.

example.ts

import { smartAccountClient as modularAccountClient } from "./smartAccountClient";
import { multiOwnerPluginActions } from "@alchemy/aa-accounts";
 

// extend smart account client with multiOwnerPluginActions to call MultiOwnerPlugin methods
const pluginActionExtendedClient = modularAccountClient.extend(
  multiOwnerPluginActions
);
 
const ownerToCheck = "0x..."; // the address of the account to check the ownership of
 
// returns a boolean whether an address is an owner of account or not
const isOwner = await pluginActionExtendedClient.isOwnerOf({
  address: ownerToCheck,
});

2. Get all current owners of a Modular Account

You can use the readOwners method on the multiOwnerPluginActions extended smart account client to fetch all current owners of the connected Modular Account.

example.ts

import { smartAccountClient as modularAccountClient } from "./smartAccountClient";
import { multiOwnerPluginActions } from "@alchemy/aa-accounts";
 

// extend smart account client with multiOwnerPluginActions to call MultiOwnerPlugin methods
const pluginActionExtendedClient = modularAccountClient.extend(
  multiOwnerPluginActions
);
 
// owners is an array of the addresses of the account owners
const owners = await pluginActionExtendedClient.readOwners();

3. Add or remove owners for a Modular Account

You can use the updateOwners method on the multiOwnerPluginActions extended smart account client to add or remove owners from the Modular Account.

example.ts

import { smartAccountClient as modularAccountClient } from "./smartAccountClient";
import { multiOwnerPluginActions } from "@alchemy/aa-accounts";
import { type Address } from "viem";
 

// extend smart account client with multiOwnerPluginActions to call MultiOwnerPlugin methods
const pluginActionExtendedClient = modularAccountClient.extend(
  multiOwnerPluginActions
);
 
const ownersToAdd: Address[] = []; // the addresses of owners to be added
const ownersToRemove: Address[] = []; // the addresses of owners to be removed
 
const result = await pluginActionExtendedClient.updateOwners({
  args: [ownersToAdd, ownersToRemove],
});
 
const txHash = await pluginActionExtendedClient.waitForUserOperationTransaction(
  result
);