Exchange SDK

About

The goal of this SDK is to provide an easy way to interact with Ledger Live for exchange methods (example: Swap).

This LiveApp is an example of how to interact with ExchangeSDK to ask user to validate a swap transaction.

To have more details on how the swap features is working in Ledger Live, go to Ledger's dev portal.

Installation

npm install @ledgerhq/exchange-sdk

Prerequisite

LiveApp Settings

Your LiveApp will need to have the following permissions in your manifest.json file:

  "permissions": [
    "account.list",
    "account.request",
    "currency.list",
    "custom.exchange.start",
    "custom.exchange.complete"
  ]

Usage

First you need an instance of the ExchangeSDK:

import { ExchangeSDK, QueryParams } from "@ledgerhq/exchange-sdk";

// The providerId has to be set with coordination with Ledger's team. It is your unique identifier when interacting with Ledger Live.
const exchangeSDK = new ExchangeSDK(providerId);

When your LiveApp is called by Ledger Live through a deeplink, it will receive some informations. Check QueryParams type to have more details about it.

Then you can call the swap method in order to start a new swap process.

// Those are parameters that given through deeplink.
exchangeSDK.swap({
  quoteId,
  fromAccountId,
  toAccountId,
  fromAmount,
  feeStrategy,
  customFeeConfig,
  rate,
  toNewTokenId
});

You can update some of them (ex: quoteId), if your interface offers the user to change those parameters. Typically, the quoteId is an information coming from your system, so you can update its value if during your interaction with the user it has more mearning to do so.

toNewTokenId

When user swaps to a token, your app will receive toNewTokenId as a query parameter. In this case, it should be passed to swap method, without any modification. When user swaps to a native coin, this parameter won't be present, and you should not use this parameter neither in the swap method.

Using WalletAPI methods

The ExchangeSDK is a simple wrapper around the WalletAPI. However, you cannot instantiate the WalletAPI client twice inside your LiveApp.

If you want to use a method(s) provided by WalletAPI in your Live App, you have two options:

• use the WalletAPI client instance provided by the ExchangeSDK or
• pass the WalletAPI client instance as the second parameter when invoking the ExchangeSDK()

Option 1: Having a direct dependency with exchange-sdk only

Once you have your ExchangeSDK instance, you can call WalletAPI methods through its walletAPI property:

exchangeSDK.walletAPI.account.list();

Option 2: Having a direct dependency with wallet-api & exchange-sdk

If you already have a WalletAPI client instance, you can provide it when instanciating the ExchangeSDK:

const exchangeSDK = new ExchangeSDK(providerId, undefined, myWalletAPI);

The example app

/example/src/pages/index.tsx

useEffect is used when the LiveApp is launch. It catches the deeplink query params provided to populate the form inputs. Then it instanciate an ExchangeSDK with a default providerId.

onSwap gets all form inputs info to send them to the ExchangeSDK. For testing purpose, a default quoteId is provided, but in Production this query param is mandatory.

Testing

You can test your integration by setting a custom url for the backend called by this SDK. Instanciate the exchangeSDK this way:

const exchangeSDK = new ExchangeSDK(providerId, undefined, undefined, "https://custom-url.swap.test");

Why

lib/package.json has 2 pre/post script on bump version. This is due to an NPM issue.