How to build a wallet

This guide shows how to build either an WebExtension Wallet or a iFrame-based Wallet.

WebExtension wallet

The full implementation of this example can be found here:

• WebExtension Wallet Example

Note:

• If you want to see a more advanced implementation you can take a look into the repository of the Superhero Wallet

1. Create bridge between extension and page

First you need to create a bridge between your extension and the page. This can be done as follows:

import {
  BrowserRuntimeConnection, BrowserWindowMessageConnection, AeppWalletSchema,
  ContentScriptBridge, AeppWalletHelpers
} from '@aeternity/aepp-sdk'

const readyStateCheckInterval = setInterval(function () {
  if (document.readyState === 'complete') {
    clearInterval(readyStateCheckInterval)

    const port = AeppWalletHelpers.getBrowserAPI().runtime.connect()
    const extConnection = BrowserRuntimeConnection({
      connectionInfo: {
        description: 'Content Script to Extension connection',
        origin: window.origin
      },
      port
    })
    const pageConnection = BrowserWindowMessageConnection({
      connectionInfo: {
        description: 'Content Script to Page connection',
        origin: window.origin
      },
      origin: window.origin,
      sendDirection: AeppWalletSchema.MESSAGE_DIRECTION.to_aepp,
      receiveDirection: AeppWalletSchema.MESSAGE_DIRECTION.to_waellet
    })

    const bridge = ContentScriptBridge({ pageConnection, extConnection })
    bridge.run()
  }
}, 10)

2. Initialize RpcWallet Stamp

Then you need to initialize RpcWallet Stamp in your extension and subscribe for new runtime connections. After the connection is established you can share the wallet details with the application.

// ideally this can be configured by the users of the extension
const NODE_URL = 'https://testnet.aeternity.io'
const COMPILER_URL = 'https://compiler.aepps.com'
const accounts = [
  MemoryAccount({ keypair: Crypto.generateKeyPair() }), // generate keypair for account1
  MemoryAccount({ keypair: Crypto.generateKeyPair() })  // generate keypair for account2
]

async function init () {
  // Init extension stamp from sdk
  RpcWallet({
    compilerUrl: COMPILER_URL,
    nodes: [{ name: 'testnet', instance: await Node({ url: NODE_URL }) }],
    name: 'Wallet WebExtension',
    // The `ExtensionProvider` uses the first account by default. You can change active account using `selectAccount(address)` function
    accounts,
    // Hook for sdk registration
    onConnection (aepp, action) {
      if (confirm(`Aepp ${aepp.info.name} with id ${aepp.id} wants to connect`)) {
        action.accept()
      } else {
        action.deny()
      }
    },
    onDisconnect (msg, client) {
      console.log('Disconnect client: ', client)
    },
    onSubscription (aepp, action) {
      if (confirm(`Aepp ${aepp.info.name} with id ${aepp.id} wants to subscribe for accounts`)) {
        action.accept()
      } else {
        action.deny()
      }
    },
    onSign (aepp, action) {
      if (confirm(`Aepp ${aepp.info.name} with id ${aepp.id} wants to sign tx ${action.params.tx}`)) {
        action.accept()
      } else {
        action.deny()
      }
    },
    onAskAccounts (aepp, action) {
      if (confirm(`Aepp ${aepp.info.name} with id ${aepp.id} wants to get accounts`)) {
        action.accept()
      } else {
        action.deny()
      }
    },
    onMessageSign (aepp, action) {
      if (confirm(`Aepp ${aepp.info.name} with id ${aepp.id} wants to sign msg ${action.params.message}`)) {
        action.accept()
      } else {
        action.deny()
      }
    }
  }).then(wallet => {
    chrome.runtime.onConnect.addListener(async function (port) {
      // create connection
      const connection = await BrowserRuntimeConnection({ connectionInfo: { id: port.sender.frameId }, port })
      // add new aepp to wallet
      wallet.addRpcClient(connection)
      // share wallet details
      wallet.shareWalletInfo(port.postMessage.bind(port))
      setTimeout(() => wallet.shareWalletInfo(port.postMessage.bind(port)), 3000)
    })
  }).catch(err => {
    console.error(err)
  })
}

init().then(_ => console.log('Wallet initialized!'))

iFrame-based Wallet

The iFrame-based approach works similar to the WebExtension approach except that the ContentScriptBridge in between isn't needed.

You can take a look into the implementation of the following example to see how it works:

• iFrame-based Wallet Example