@hashgraph/hedera-wallet-connect

Overview

This library is the result of Hedera community collaboration to bring Hedera into the WalletConnect ecosystem and vice versa.

The goal of this repository is to be a reference for wallets and dApps integrating the WalletConnect <> Hedera JSON-RPC reference. Additionally, this library is meant to be included in projects supporting WalletConnect and Hedera, providing utility functions useful to validating requests and resposes in both the WalletConnect JSON-RPC context as well as the Hedera context.

A few useful resources include:

• HIP-820
• WalletConnect <> Hedera JSON-RPC spec.

WalletConnect brings the ecosystem together by enabling wallets and apps to securely connect and interact.

-- https://walletconnect.com

Hedera aims to be:

The open source public ledger for everyone

-- https://hedera.com

---

This package managed by the Hedera community and is intended to be a standard for ecosystem wallets and dApp providers utilizing WalletConnect as a their communications protocol. It utilizes the @hashgraph/sdk and provides functions to facilitate implementing the WalletConnect <> Hedera JSON-RPC spec which has been defined through the collaborative HIP process in HIP-820.

This library facilitates the implementation of the WalletConnect <> Hedera Spec which allows wallets and dApps to natively integrate with Hedera. It provides additional, out of network functionality with the hedera_signMessage function.

In short, it uses the Hedera javascript SDK to build transactions, serialize them, send to wallets for processing and return responses back to dApps.

Please note, this is distinct from the Implementation of Ethereum JSON-RPC APIs for Hedera. At the time of this writing, "the Hedera JSON-RPC relay implementation is in beta, offers limited functionality today, and is only available to developers."

The relay and this library have different intentions and serve different purposes - namely native Hedera integration vs. Ethereum compatability layers to ease developer onboarding for those more familiar with the Ethereum ecosystem.

Set up

To start using WalletConnect, sign up for an account at https://cloud.walletconnect.com. You will use your project id when initializing client libraries.

It is important to understand core WalletConnect concepts when integrating this library. Please reference the WalletConnect documentation.

Usage

Upon successfully configuring your dApp and/or wallet to manage WalletConnect sessions, you can use this library’s functions to easily create and handle requests for the Hedera network.

DApps

Signer

This library provides a DAppSigner class that implements the @hashgraph/sdk's Signer interface. You may use the DAppSigner class to sign and execute transactions on the Hedera network.

Get Signer

After you have paired your wallet with your dApp, you can get the signer from the DAppConnector instance:

const signer = dAppConnector.signers[0] // DAppSigner

Or, if multiple signers are available, you can find the signer by account ID:

const signer = dAppConnector.signers.find(
  (signer_) => signer_.getAccountId().toString() === '0.0.100',
) // DAppSigner

Sign Transactions

const transaction = new TransferTransaction()
  .addHbarTransfer('0.0.100', new Hbar(-1))
  .addHbarTransfer('0.0.101', new Hbar(1))

await transaction.freezeWithSigner(signer)
const signedTransaction = await signer.signTransaction(transaction)

Sign and Execute Transactions

const transaction = new TransferTransaction()
  .addHbarTransfer('0.0.100', new Hbar(-1))
  .addHbarTransfer('0.0.101', new Hbar(1))

await transaction.freezeWithSigner(signer)
const transactionResponse = await transaction.executeWithSigner(signer)

Sign and verify messages

const text = 'Example message to sign'
const base64String = btoa(text)

const sigMaps = await signer.sign([base64StringToUint8Array(base64String)]) // import { base64StringToUint8Array } from '@hashgraph/hedera-wallet-connect'

// sigMaps[0].publicKey also contains the public key of the signer, but you should obtain a PublicKey you can trust from a mirror node.
const verifiedResult = verifySignerSignature(base64String, sigMaps[0], publicKey) // import { verifySignerSignature } from '@hashgraph/hedera-wallet-connect'

Wallet

This library provides a Wallet class that extends the Web3Wallet class provided by WalletConnect class

Event Listeners

WalletConnect emits various events during a session. Listen to these events to synchronize the state of your application:

// Handle pairing proposals
signClient.on('session_proposal', (event) => {
  // Display session proposal to the user and decide to approve or reject
})

// Handle session requests, like signing transactions or messages
signClient.on('session_request', (event) => {
  // Process the session request
})

// Handle session deletions
signClient.on('session_delete', (event) => {
  // React to session termination
})

Pairing with dApps

Pairing establishes a connection between the wallet and a dApp. Once paired, the dApp can send session requests to the wallet.

a. Pairing via URI

If a dApp shares a URI for pairing:

await signClient.core.pairing.pair({ uri: 'RECEIVED_URI' })

Upon successful pairing, the session_proposal event will be triggered.

b. Pairing via QR Codes

For a better user experience, dApps often share QR codes that wallets can scan to establish a pairing. Use a QR code scanning library to scan and obtain the URI, then proceed with pairing:

const scannedUri = '...' // URI obtained from scanning the QR code
await signClient.core.pairing.pair({ uri: scannedUri })

Handling Session Proposals

Upon receiving a session_proposal event, display the proposal details to the user. Allow them to approve or reject the session:

Handling Session Requests

Upon receiving a session_request event, process the request. For instance, if the dApp requests a transaction to be signed:

Demo & docs

This repository includes a vanilla html/css/javascript implementation with a dApp and wallet example useful for testing and development while integrating WalletConnect and Hedera.

The docs site utilizes Typedoc to generate a library documentation site at https://wc.hgraph.app/docs/

The demo source code lives in ./src/examples/typescript and is available at https://wc.hgraph.app

Passing tests

• git commit -Ss "the commit message"