# Flutter SDK - v3 to v4

>  Flutter SDK - v3 to v4 | Embedded Wallets

# Migration guide from v3 to v4 for Embedded Wallets Flutter SDK

## Overview

This migration guide provides steps for upgrading from version 3(v3) to version 4(v4) of the Embedded Wallets Flutter SDK. The guide outlines significant changes and enhancements, including the introduction of `enableMFA` method to initiate MFA setup flow, `request` method for transaction confirmation screens, `launchWalletServices` method for template wallet interface, updates to the `Provider` and the `TypeOfLogin` enum.

## Changes in detail

### `setResultUrl` is removed

With the new v4 update, there's a breaking change with the removal of the `setResultUrl` method, which was used to trigger the user `UserCancelledException` on Android.

From v4, developers won't be able to use the `setResultUrl` method.

### `enableMFA` method

From v4, developers can now use the `enableMFA` method to initiate MFA setup flow for already logged in users.

<Tabs
  defaultValue="default-verifier"
  values={[
    { label: "Default Verifier", value: "default-verifier" },
    { label: "Custom JWT Verifier", value: "custom-jwt-verifier" },
  ]}
>

<TabItem value="default-verifier">

```dart title="Usage"
try {
  // focus-next-line
  await Web3AuthFlutter.enableMFA();
} on UserCancelledException {
  log("User cancelled.");
} catch(e) {
  log("Unknown exception occurred");
}
```

</TabItem>

<TabItem value="custom-jwt-verifier">

```dart title="Usage"
try {
    final loginParams = LoginParams(
        loginProvider: Provider.jwt,
        extraLoginOptions: ExtraLoginOptions(
            id_token: "YOUR_JWT_TOKEN",
        ),
    );

    // focus-next-line
    await Web3AuthFlutter.enableMFA(loginParams);

} on UserCancelledException {
  log("User cancelled.");
} catch(e) {
    log("Unknown exceptionoccurred");
}

```

</TabItem>
</Tabs>

### `launchWalletServices` method

From v4, developers can use the `launchWalletServices` to launches a WebView which allows them to use the templated wallet UI services. Developers can pass the `ChainConfig` to launch Wallet Services with a specific chain selected.

:::note

Access to Wallet Services is gated. You can use this feature in `sapphire_devnet` for free. The minimum [pricing plan](https://web3auth.io/pricing.html) to use this feature in a production environment is the **Scale Plan**.

:::

#### ChainConfig arguments

| Parameter           | Description                                                                                                                 |
| ------------------- | --------------------------------------------------------------------------------------------------------------------------- |
| `chainNamespace`    | Custom configuration for your preferred blockchain. As of now only EVM supported. Default value is `ChainNamespace.eip155`. |
| `decimals?`         | Number of decimals for the currency ticker. Default value is 18, and accepts `int` as value.                                |
| `blockExplorerUrl?` | Blockchain's explorer URL. (for example, `https://etherscan.io`)                                                            |
| `chainId`           | The chain ID of the selected blockchain in hex `String`.                                                                    |
| `displayName?`      | Display Name for the chain.                                                                                                 |
| `logo?`             | Logo for the selected `chainNamespace` and `chainId`.                                                                       |
| `rpcTarget`         | RPC Target URL for the selected `chainNamespace` and `chainId`.                                                             |
| `ticker?`           | Default currency ticker of the network (for example, `ETH`).                                                                |
| `tickerName?`       | Name for currency ticker (for example, `Ethereum`).                                                                         |

#### Usage

```dart title="Usage"
try {
  // focus-start
  await Web3AuthFlutter.launchWalletServices(
    ChainConfig(
      chainId: "0x1",
      rpcTarget: "https://mainnet.infura.io/v3/$key",
    ),
  );
  // focus-end
} on UserCancelledException {
  log("User cancelled.");
} catch(e) {
  log("Unknown exception occurred");
}
```

### `request` method

Now, developers can use the `request` method to use the templated transaction confirmation screens for signing transactions. To retrive the signature for the request, developers can use the `getSignResponse` static method.

```dart title="Usage"
try {
  List<dynamic> params = [];
  // Message to be signed
  params.add("Hello, Web3Auth from Flutter!");
  // User's EOA address
  params.add("<User Address in Hex>");

  // focus-start
  await Web3AuthFlutter.request(
    ChainConfig(
      chainId: "0x1",
      rpcTarget: "https://mainnet.infura.io/v3/$key",
    ),
    "personal_sign",
    params,
  );
  // focus-end
} on UserCancelledException {
  log("User cancelled.");
} catch(e) {
  log("Unknown exception occurred");
}

// focus-next-line
final signResponse = await Web3AuthFlutter.getSignResponse();
log(signResponse.toString())
```

### New login providers

v4 update brings two new providers: SMS Passwordless and Farcaster login.

#### SMS Passwordless

```dart title="Usage"
Future<void> initWeb3Auth() async {
  Uri redirectUrl;
  if (Platform.isAndroid) {
    redirectUrl = Uri.parse('{SCHEME}://{HOST}/auth');
    // w3a://com.example.w3aflutter/auth
  } else if (Platform.isIOS) {
    redirectUrl = Uri.parse('{bundleId}://auth');
    // com.example.w3aflutter://openlogin
  } else {
    throw UnKnownException('Unknown platform');
  }

  await Web3AuthFlutter.init(
    Web3AuthOptions(
      clientId: "WEB3AUTH_CLIENT_ID",
      network: Network.sapphire_mainnet,
      redirectUrl: redirectUrl,
    ),
  );
}

// Login
final Web3AuthResponse response = await Web3AuthFlutter.login(
  LoginParams(loginProvider: Provider.sms_passwordless,
    // focus-start
    extraLoginOptions: ExtraLoginOptions(
      // The phone number should be in format of +{country_code}-{phone_number}
      login_hint: "+91-9911223311",
    ),
    // focus-end
  ),
);
```

#### Farcaster

```dart title="Usage"
final Web3AuthResponse response = await Web3AuthFlutter.login(
  // focus-next-line
  LoginParams(loginProvider: Provider.farcaster)
);
```