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Prerequisites

This guide assumes that you have completed the setup guide.

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Authenticate your user

Privy offers a variety of authentication mechanisms. The example below showcases authenticating a user via SMS.

This is a two step process:

  1. Send an OTP to the user provided phone number.
  2. Verify the OTP sent to the user.

Please be sure to configure SMS as a login method on the Privy Developer Dashboard under User Management > Authentication.

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1. Send an OTP to the user’s phone number via SMS

After collecting and validating your users phone number, send an OTP by calling the sendCode method. Note: you must provide the phone number in E.164 format.

do {
    let phoneNumber = "+14155552671"
    try await privy.sms.sendCode(to: phoneNumber)
    // OTP sent successfully - prompt user for OTP
} catch {
    // OTP could fail if the network request fails
    print("Error sending code: \(error))
}

If the OTP is sent successfully, sendCode will not throw an error. If the provided phone number is invalid, or sending the OTP fails, sendCode will throw an error.

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2. Authenticate with OTP

The user will then receive an SMS with a 6-digit OTP. Prompt for this OTP within your application, then authenticate the user with the loginWithCode method. Pass the following parameters to this method:

do {
    let phoneNumber = "+14155552671"
    let inputtedOtp = "123456"
    let privyUser = try await privy.sms.loginWithCode(inputtedOtp, sentTo: phoneNumber)
    print("Logged in with sms! User: \(privyUser.id)")
} catch {
    print("Error logging user in: \(error)")
}

If the OTP/phone number combination is valid, Privy will successfully authenticate your user and loginWithCode will return the PrivyUser. If the provided OTP/phone number combination is invalid, loginWithCode will throw an error that speicfies the error reason.

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The embedded wallet

Privy’s embedded wallets are compatible with the Ethereum and Solana blockchains.

Creating the embedded wallet

To create an EVM embedded wallet for your user, call PrivyUser.createEthereumWallet.

public protocol PrivyUser {
    // Other privy user methods

    func createEthereumWallet(allowAdditional: Bool) async throws -> EmbeddedEthereumWallet
}

If a wallet is successfully created for the user, the newly created EmbeddedEthereumWallet is returned.

The method will throw an error if

  • The user is not authenticated
  • If a user already has 9 or more wallets
  • If the network call to create the wallet fails
  • If a user already has an embedded wallet and allowAdditional is not set to true.

Example

if let user = privy.user {
    // If user not null, user is authenticated
    do {
        let ethereumWallet = try await user.createEthereumWallet()
        print("Created wallet with address: \(ethereumWallet.address)")
    } catch {
        print("Error creating embedded wallet: \(error.localizedDescription)")
    }
}

Using the embedded wallet

To enable your app to request signatures and transactions from the embedded wallet, Privy Ethereum embedded wallets expose a provider inspired by the EIP-1193 provider standard. This allows you request signatures and transactions from the wallet via a familiar JSON-RPC API (e.g. personal_sign).

Once you have an instance of an EmbeddedEthereumWallet, you can make RPC requests by using the provider: EmbeddedEthereumWalletProvider hook and using its request method. For example, wallet.provider.request(request: rpcRequest).

public protocol EmbeddedEthereumWallet: EmbeddedWalletBehavior {
    var provider: EmbeddedEthereumWalletProvider { get }
}

As a parameter to this method, to this method, pass an EthereumRpcRequest object that contains:

  • method: the name of the JSON-RPC method for the wallet to execute (e.g. personal_sign)
  • params: an array of parameters required by your specified method

By default, embedded wallets are connected to the Ethereum mainnet. To send a transaction on a different network, simply set the wallet’s chainId in the transaction request.

Example

if let user = privy.user {
    // If user not null, user is authenticated
    do {
        // Retrieve list of user's embedded Ethereum wallets
        let ethereumWallets = user.embeddedEthereumWallets

        // Grab the desired wallet. Here, we retrieve the first wallet
        if let wallet = ethereumWallets.first {
            let data = EthereumRpcRequest(method: "personal_sign", params: ["A message to sign", wallet.address])
            let signature = try await wallet.provider.request(data)
            print("Result signature: \(signature)")
        }
    } catch {
        print("personal_sign error: \(error.localizedDescription)")
    }
}

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