# Migrating from the Platform API

This guide aim to help migrating from the **Platform API** _(live-app-sdk)_ to the newer **Wallet-API**.

## Key Differences

Although they mostly serve the same purpose, there are many key differences that separate the Wallet-API from the
Platform API. Here is a list of those key differences:

1. **Introspective design:** Wallet-API was designed to be implemented on uneven wallets. Some wallets will implement
   all existing features, some won't. Live apps are now able to request a wallet's specific capabilities and adapt their
   UX based on those.
2. **Method permissions:** Wallet-API adds plenty of new features. Since they can be used freely by the live app, it
   made sense to restrict which app can use which method. Similarily to mobile apps and browser extensions, live apps now
   need to declare which methods they intend to use in their respective manifests.
3. **Currency permissions:** Most live apps will only focus on a few specific crypto currencies. To avoid exposing
   un-needed user account informations, live apps now have to declare in their manifests which currencies they intend to
   use.
4. **More coin family support:** Wallet-API implement more crypto currency families than the Platform API. Please
   refer to the doc to discover newly integrated crypto families.
5. **Unsollicited events:** Wallet-API enable live apps to subscribe to wallet events. This can be used to be notified
   of any emitted events from the wallet.

## Migrating the manifest

The manifest format hasn't been updated, however, some unused fields are now being used. Here is a list of the
required modifications:

### `apiVersion`

This field need to be set at version `^2.0.0` to ensure the connected wallet will expose the Wallet-API. If a lower
version is used, the Platform API will be exposed instead

```json
{
  ...
    "apiVersion": "^2.0.0",
}
```

### `currencies`

This field now specify which currencies will be used by the live app. From the point of view of the live app, the
wallet won't support crypto currencies that are not included in this list.

```json
{
  ...
    "currencies": [
  "ethereum",
  "bitcoin"
  ...
  ],
}
```

### `permissions`

This field now specify which methods can be used by the live app. Trying to use a method that wasn't declared in this
list will result in a permission error.

```json
{
  ...
    "permissions": [
  "currency.list",
  "account.list",
  "account.request",
  ...
  ],
}
```

## Migrating the live app

Live apps using the Platform API are using the `@ledgerhq/live-app-sdk` package. This package provided a vanilla JS
client instance that could be used to communicate with the connected wallet. We now provide **two packages** to
integrate the Wallet-API into your website:

### `@ledgerhq/wallet-api-client`

The minimal implementation is pretty similar to the `@ledgerhq/live-app-sdk`. This new package expose a vanilla JS
`WalletAPIClient` class. Please refer to [the core section](../core/getting-started) for more. Here are a few differences:

1. **Signing transactions:** The `broadcastSignedTransaction` endpoint was removed. There are now only two ways to
   sign a transaction, with **transaction.sign** or **transaction.signAndBroadcast**. The first one will trigger a
   signature flow and return a **signed transaction**, the second one will trigger a signature flow and broadcast the
   signed transaction in one go, returning the **transaction hash**.
2. **Transports:** Transport is an interface for a simple connector allowing the live app to connect to the wallet.
   `WindowMessageTransport` is still provided, but it now require the user to call `connect()` before it can be used.

### `@ledgerhq/wallet-api-client-react`

React typically makes it difficult to manage anything that is **instance based**. Doing so generally involve more
advanced concepts such as _reference management_ and can introduce a lot of **bugs and complexity**. Although some
developers might want to manage the integration themselves, we now offer a react wrapper library in order facilitate
Wallet-API integration in their website, we are now providing the `@ledgerhq/wallet-api-client-react` library. This
library is exposing both a provider and a set of react hooks, facilitating integration.