MPC Authenticator JS library

Getting started

Install the SDK:

npm i --save @silencelaboratories/universal-mpc-auth

Overview:

The library provides the following 2 main components:

1. MpcAuthenticator
2. MpcSigner

MpcAuthenticator

The MpcAuthenticator class is designed to handle authentication processes using MPC SDK for {2,2} TSS.

import {
  MpcAuthenticator,
  StoragePlatform,
  WalletId,
} from "@silencelaboratories/universal-mpc-auth";

// 1. Set up MpcAuthenticator with custom storage and development mode
const storage = new CliStorage(); // Ref: https://github.com/silence-laboratories/mpc-auth-client/blob/staging/packages/biconomy/cli/mpc/storage.ts

const mpcAuth = MpcAuthenticator.instance({
  walletId: WalletId.Biconomy,
  storagePlatform: StoragePlatform.CLI,
  customStorage: storage,
  isDev: process.env.NEXT_PUBLIC_SDK_MODE === "development",
});

// 2. Generate QR code for Silent Shard App pairing
const qrCode = await mpcAuth.initPairing();

// ... Scanning happens

const pairingSessionData = await mpcAuth.runStartPairingSession();
await mpcAuth.runEndPairingSession(pairingSessionData);

// 3. Key generation after pairing is done
const keygenResult = await mpcAuth.runKeygen(); // The generated keyshares will be stored to do signing later

// 4. (Optional) Sent backup to Silent Shard App for key restoration later
await mpcAuth.runBackup("demopassword");

MpcAuthenticator options

• walletId - Supported Wallet ID to use for identifying the wallet. Check WalletId enum for available options.
• storagePlatform - Supported Storage platform to use for storing keyshares and pairing data. Check StoragePlatform enum for available options.
• customStorage - Custom storage object to use for storing keyshares and pairing data. If not provided, the library will use the default storage, which is localStorage (assuming the library is used in the browser).
• isDev - Development mode flag. If set to true, the library will use the development mode for the MPC SDK.

Custom Storage

The library provides a way to use custom storage for data storing. The custom storage must implement IStorage interface, MpcAuthenticator will access the storage using the provided methods.

interface IStorage {
  clearStorageData: () => Promise<void>;
  setStorageData: (data: StorageData) => Promise<void>;
  getStorageData: () => Promise<StorageData>;
  migrate?(): void;
}

MpcSigner

The MpcSigner class is designed for signing Ethereum transactions and messages using MpcAuthenticator keyshares.

An example of MpcSigner with Biconomy account creation:

// MpcSigner initialization
const provider = new providers.JsonRpcProvider("https://rpc.sepolia.org");
const mpcSigner = await MpcSigner.instance(mpcAuth, provider); // Now, mpcSigner could be used to sign ETH transactions
const biconomySmartAccount = await createSmartAccountClient({
  signer: client as SupportedSigner,
  bundlerUrl: `https://bundler.biconomy.io/api/v2/11155111/${process.env.API_KEY}`,
});

ViemSigner

The ViemSigner class is designed to facilitate signing Ethereum transactions and messages using a MpcAuthenticator for key management. This signer integrates with the viem library to provide a seamless signing experience.

An example of ViemSigner with Pimlico account creation:

// ViemSigner initialization
const client = await ViemSigner.instance(mpcAuth);
const signer = await client.getViemAccount();
const walletClient = createWalletClient({
  account: signer,
  chain: sepolia,
  transport: http(
    `https://rpc.zerodev.app/api/v2/bundler/${process.env.API_KEY}`
  ),
});
const smartAccountSigner = walletClientToSmartAccountSigner(walletClient);

Error codes

The library provides the following error codes:

enum BaseErrorCode {
  StorageWriteFailed = 1,
  StorageFetchFailed = 2,
  HttpError = 3,
  // Action errors
  PairingFailed = 4,
  KeygenFailed = 5,
  BackupFailed = 6,
  SignFailed = 7,
  RecoverFailed = 8,

  KeygenResourceBusy = 9,
  SignResourceBusy = 10,
  InternalLibError = 11,
  PhoneDenied = 12,
  InvalidBackupData = 13,
  InvalidMessageHashLength = 14,
  WalletNotCreated = 15,
  UnknownError = 16,
}