Ledger Connect Kit

The Ledger Connect Kit can be used to check the level of support for Ledger Connect on the user's platform. We will guide the user to install Connect or use a fallback connection to the Ledger Live app. The code is designed to be loaded at runtime from a CDN so that the logic and UI can be updated as we release new updates to Connect without the wait for wallet libraries and dapps updating package versions and releasing new builds.

The @ledgerhq/connect-kit-loader allows developers to consume Connect Kit in a transparent way.

Support status

Ledger Connect is currently only supported on Safari iOS. There are two edge cases in the detection logic:

• Safari on iPadOS is shown as supported if the user requests the mobile website, as it sets the userAgent string to be the same as iOS, otherwise the userAgent string is the same as Safari on MacOS, which is not supported yet.
• Brave on iOS is shown as supported because it sets the userAgest string to be the same as Safari on iOS, but Connect will not work.

Connect Kit loader

To use Connect Kit you just have to add the @ledgerhq/connect-kit-loader package as a dependency using your preferred package manager, using yarn as an example

yarn add @ledgerhq/connect-kit-loader

and use it as below

import { loadConnectKit } from '@ledgerhq/connect-kit-loader'

const connectKit = await loadConnectKit()

If you are using classes you can get the promise on the class constructor and its value where you need it

import { loadConnectKit } from '@ledgerhq/connect-kit-loader'

export class LedgerConnector {
  private provider: any
  private connectKitPromise: Promise<LedgerConnectKit>

  constructor() {
    super()

    this.connectKitPromise = loadConnectKit()
  }

  public async connect(): Promise<Connector> {
    if (!this.provider) {
      // load Connect Kit, check support and show a UI modal if not supported
      const connectKit = await this.connectKitPromise

You can check that Connect Kit is loaded by looking at the network tab on the developer tools. You should see a request for https://<CDN>/umd/index.js.

See what functions are provided by the Connect Kit API below.

Connect Kit API

Connect Kit exports three functions, enableDebugLogs, checkSupport and getProvider.

enableDebugLogs

Description

Enables debug messages on the console in case you need to diagnose a possible problem. Just reload the dapp to disable them.

Once Connect Kit is loaded you can call it from the browser's developer tools console with window.ledgerConnectKit.enableDebugLogs() and call the other Connect Kit functions to see the messages.

checkSupport

Parameters

type CheckSupportOptions = {
  providerType: SupportedProviders;
  chainId: ConnectSupportedChains;
  bridge?: string;
  infuraId?: string;
  rpc: { [chainId: number]: string; };
}

Returns

type ConnectSupport = type CheckSupportResult = {
  isLedgerConnectSupported?: boolean;
  isLedgerConnectEnabled?: boolean;
  isChainIdSupported?: boolean;
  providerImplementation: 'LedgerConnect' | 'WalletConnect';
}

Description

Lets you know the level of support for Ledger Connect on the user's platform, and shows a UI to guide the user.

If the Connect extension is installed and enabled you will just get the response and no UI will be shown. If Connect is not available on the user's platform one of these modals will be shown:

• Try Ledger Connect, in case the user's platform supports Connect but it is not installed or enabled; a button will be shown to let the user install the browser extension.
• Connect with Ledger Live, in case the user's platform does not support Connect they will be able to use Ledger Live Mobile or Desktop to connect.

getProvider

Returns

Promise<EthereumProvider | SolanaProvider>

Description

Based on the options passed to checkSupport it returns a promise to a Ledger Connect Ethereum provider, Ledger Connect Solana Provider or a WalletConnect provider.

Example

An example function using the Ledger Connect Kit and ethers.js, that would be called when pressing the connect button on a React app.

setProvider, setLibrary, setAccount, setChainId and setError are just simple useState functions to keep app state.

// JSX code
<Button onClick={() => connectWallet()}>Connect With Ledger</Button>

// click handler function
const connectWallet = async () => {
  try {
    const connectKit = await loadConnectKit();
    connectKit.enableDebugLogs();
    const checkSupportResult = connectKit.checkSupport({
      chainId: 1,
      providerType: SupportedProviders.Ethereum,
      rpc: {
        1: `https://cloudflare-eth.com`, // Mainnet
        137: "https://matic-mainnet.chainstacklabs.com", // Polygon
      }
    });
    console.log('checkSupportResult is', checkSupportResult);
    const provider = await connectKit.getProvider();

    const library = new ethers.providers.Web3Provider(provider);
    const accounts = await library.listAccounts();
    const network = await library.getNetwork();

    setProvider(provider);
    setLibrary(library);

    if (accounts) setAccount(accounts[0]);
    setChainId(network.chainId);
  } catch (error) {
    setError(error);
  }
}