android-aggregate-verifier-example

MetaMask Embedded Wallets — Android Grouped Connections Example

Android example demonstrating Grouped Connections (formerly Aggregate Verifiers) with MetaMask Embedded Wallets (formerly Web3Auth Plug and Play). Grouped connections allow multiple login methods — Google and Email Passwordless in this example — to resolve to the same wallet address for the same user.

Features

• Grouped connections: Google Sign-In + Email Passwordless → same wallet address
• EVM wallet creation and management
• Get wallet address, Sepolia balance, sign messages, and send transactions
• Session persistence across app restarts

Requirements

• Android Studio Hedgehog (2023.1.1) or later
• Android API 24+, Compile SDK 34
• JDK 17+
• MetaMask Embedded Wallets Dashboard account
• Google OAuth Client ID (for the Google login connection)
• Auth0 application (for the Email Passwordless connection)

Setup

1. Clone the repository

git clone https://github.com/Web3Auth/web3auth-android-examples.git
cd web3auth-android-examples/android-aggregate-verifier-example

2. Configure the Web3Auth Dashboard

1. Create a project on the Embedded Wallets Dashboard.
2. Go to Authentication → create a Grouped Connection with two sub-connections:
   • Google sub-connection — Auth Connection ID: e.g. w3a-google
   • Auth0 Email Passwordless sub-connection — Auth Connection ID: e.g. w3a-a0-email-passwordless
3. Note the Grouped Auth Connection ID (e.g. aggregate-sapphire).
4. Allowlist your redirect URI: com.sbz.web3authdemoapp://auth

3. Set credentials in strings.xml

<string name="web3auth_project_id">YOUR_WEB3AUTH_CLIENT_ID</string>
<string name="web3auth_google_client_id">YOUR_GOOGLE_CLIENT_ID</string>
<string name="web3auth_auth0_client_id">YOUR_AUTH0_CLIENT_ID</string>

4. Open in Android Studio and run

How It Works

Initialize Web3Auth with grouped connection config

private const val GROUPED_AUTH_CONNECTION_ID = "aggregate-sapphire"
private const val GOOGLE_AUTH_CONNECTION_ID = "w3a-google"
private const val AUTH0_AUTH_CONNECTION_ID = "w3a-a0-email-passwordless"
private const val AUTH0_DOMAIN = "https://web3auth.au.auth0.com"

val authConnections = listOf(
    AuthConnectionConfig(
        authConnectionId = GOOGLE_AUTH_CONNECTION_ID,
        authConnection = AuthConnection.GOOGLE,
        clientId = getString(R.string.web3auth_google_client_id),
        groupedAuthConnectionId = GROUPED_AUTH_CONNECTION_ID
    ),
    AuthConnectionConfig(
        authConnectionId = AUTH0_AUTH_CONNECTION_ID,
        authConnection = AuthConnection.CUSTOM,
        clientId = getString(R.string.web3auth_auth0_client_id),
        groupedAuthConnectionId = GROUPED_AUTH_CONNECTION_ID,
        jwtParameters = ExtraLoginOptions(
            domain = AUTH0_DOMAIN,
            userIdField = "email",
            isUserIdCaseSensitive = false
        )
    )
)

web3Auth = Web3Auth(
    Web3AuthOptions(
        clientId = getString(R.string.web3auth_project_id),
        web3AuthNetwork = Web3AuthNetwork.SAPPHIRE_MAINNET,
        redirectUrl = "com.sbz.web3authdemoapp://auth",
        authConnectionConfig = authConnections
    ), this
)

web3Auth.setResultUrl(intent?.data)

val sessionResponse: CompletableFuture<Void> = web3Auth.initialize()
sessionResponse.whenComplete { _, error ->
    if (error == null) {
        val credentials = Credentials.create(web3Auth.getPrivateKey())
    }
}

Login with Google

val loginFuture: CompletableFuture<Web3AuthResponse> =
    web3Auth.login(LoginParams(Provider.GOOGLE))

loginFuture.whenComplete { _, error ->
    if (error == null) {
        val credentials = Credentials.create(web3Auth.getPrivateKey())
    }
}

Login with Email Passwordless (Auth0)

val loginFuture: CompletableFuture<Web3AuthResponse> =
    web3Auth.login(
        LoginParams(
            Provider.JWT,
            extraLoginOptions = ExtraLoginOptions(
                domain = AUTH0_DOMAIN,
                verifierIdField = "email",
                isVerifierIdCaseSensitive = false
            )
        )
    )

Both login methods resolve to the same wallet address because they share the same groupedAuthConnectionId.

Handle deep link callbacks

override fun onNewIntent(intent: Intent?) {
    super.onNewIntent(intent)
    web3Auth.setResultUrl(intent?.data)
}

override fun onResume() {
    super.onResume()
    if (Web3Auth.getCustomTabsClosed()) {
        web3Auth.setResultUrl(null)
        Web3Auth.setCustomTabsClosed(false)
    }
}

Resources

• Android SDK Documentation
• Custom Authentication Guide
• MetaMask Embedded Wallets Docs
• Dashboard
• Builder Hub Community

License

MIT — see LICENSE for details.