Multi-Chain Connect

DID Connect is designed with interoperability in mind, extending its capabilities beyond the ArcBlock ecosystem. You can configure it to seamlessly interact with other major blockchains, such as Ethereum and Solana. This example demonstrates how to set up a DID Connect session to request actions on the Ethereum network.

The key to multi-chain functionality is the chainInfo object, which tells the user's wallet which network to connect to for the session.

The chainInfo Object#

To initiate a request on a specific blockchain, you must provide a chainInfo object. This object specifies the target network's type, ID, and connection endpoint.

Here are the fields for the chainInfo object:

Field

Type

Description

Required

type

string

The type of blockchain. Supported values are 'arcblock', 'ethereum', and 'solona'.

Yes

id

string

The network's Chain ID. For example, '1' for Ethereum Mainnet or '11155111' for the Sepolia testnet.

For ethereum, solona

host

string

The RPC endpoint for the network. While optional, it's highly recommended for reliable communication.

No

Example: Requesting a Signature on Ethereum#

Let's walk through an example of how to request a user to sign a message using their Ethereum account on the Sepolia testnet.

First, define the chainInfo for the target network. This object will be passed to WalletHandlers to configure the DID Connect session.

Ethereum Chain Configuration

const ethereumChainInfo = {
  type: 'ethereum',
  id: '11155111', // Sepolia Chain ID
  host: 'https://sepolia.infura.io/v3/YOUR_INFURA_PROJECT_ID', // Example RPC endpoint
};

Next, use this configuration within the handlers.attach method. You can set the chainInfo in the authPrincipal claim to define the context for the entire session. You can also specify it for individual claims if you need to orchestrate a workflow across multiple chains.

Attaching Wallet Handlers

const { WalletHandlers } = require('@arcblock/did-connect');

// Assuming 'authenticator' and 'tokenStorage' are already configured
const handlers = new WalletHandlers({ authenticator, tokenStorage });

handlers.attach({
  app: server, // Your Express.js app instance
  action: 'eth-signature',

  // Set the chain context for the entire authentication request
  authPrincipal: {
    chainInfo: ethereumChainInfo,
  },

  // Define the claims to be requested on the specified chain
  claims: {
    signature: () => ({
      typeUrl: 'eth:personal-data', // Request a personal signature
      display: 'Sign a message to verify your Ethereum account',
      origin: 'https://yourapp.com',
      // This is optional if authPrincipal.chainInfo is set
      chainInfo: ethereumChainInfo, 
    }),
  },

See all 8 lines

How It Works#

  1. When your application generates the DID Connect QR code, it will be encoded with the Ethereum chainInfo you provided.
  2. The user scans the QR code with a compatible wallet like ABT Wallet.
  3. The wallet recognizes the type: 'ethereum' and prompts the user to switch to the Sepolia Ethereum network.
  4. The user is then asked to sign the message using their selected Ethereum account.
  5. Upon approval, the wallet sends the signature back to your application, which you can then process in the onAuth callback.

This same pattern can be applied to other chains like Solana by simply changing the chainInfo object accordingly. This powerful feature allows you to build decentralized applications that leverage identities and assets across multiple blockchain ecosystems.

Multi-Step Session