Meso iOS Example

A reference implementation for integrating Meso's on/off ramps into iOS applications.

For more details on the Meso integration, view the meso-js docs.

Meso does not have an official iOS SDK. However, this repo demonstrates the steps required to use Meso in an iOS application. Instead of rendering the Meso experience inside an iframe, this uses a WebView. The example helper library does two things:

• Manages the lifecycle a WebView (WKWebView) that renders the Meso transfer experience.
• Configures postMessage capabilities between the Meso window and your application. See Events for more.

📓 Currently, the SDK is in private beta. To request access, contact support@meso.network.

Requirements

Account setup

To use Meso, you must have a Meso partner account. You can reach out to support@meso.network to sign up. During the onboarding process, you will need to specify the origin of your dApp or web application to ensure the Meso window operates within your application. Meso will then provide you with a partnerId for use with the SDK.

Usage

The demo application is built in Swift and uses SwiftUI. Using SwiftUI is not a requirement.

The logic for initializing and managing the Meso window lives in Meso.swift. This library is used inside of the main ContentView.

To initialize Meso, you will need to configure the transfer (see reference for details).

// This is an example static configuration. Typically, this will by dynamically populated in your application at runtime.
let mesoTransferConfiguration = MesoTransferConfiguration(
    partnerId: "<YOUR_PARTNER_ID>",
    network: Network.solanaMainnet,
    // This is just an example Solana address. You will need to input your own wallet.
    walletAddress: walletAddress,
    sourceAmount: transferAmount,
    destinationAsset: Asset.sol,
    environment: Environment.sandbox
)
let meso = Meso(configuration: mesoTransferConfiguration)

meso.on { event in
    switch event {
    case .configurationError(let payload):
        print("[Configuration Error]: \(payload)")
    case .unsupportedAssetError(let payload):
        print("[Unsupported Asset Error]: \(payload)")
    case .unsupportedNetworkError(let payload):
        print("[Unsupported Network Error]: \(payload)")
    case .requestSignedMessage(let payload, let callback):
        // This demonstrates a generic method of signing messages with Solana wallets. In the real world, you would
        // typically use a library or your own signing implementation.
        // If the user cancels or rejects signing, or there is a failure, return nil – `callback(nil)`
        callback(signMessage(messageToSign: payload.messageToSign))
    case .close:
        showMeso = false
    case .transferApproved(let payload):
        print("Handling `transferApproved` \(payload.transfer.id), \(payload.transfer.status)")
    case .transferComplete(let payload):
        let networkTransactionId = payload.transfer.networkTransactionId ?? "unknown"
        print("Transfer complete! mesoId: \(payload.transfer.id), networkTransactionId: \(networkTransactionId)")
        showMeso = false
    default:
        print("Unknown or discarded event")
    }
}

You can then call meso.transfer() when you want to render Meso in a WebView.

Example:

For example, in a SwiftUI View, you can do something like this:

let meso = Meso(...) // Your Meso configuration

meso.on { event in
  // Handle events from Meso
}

struct ContentView: View {
    @State private var showMeso = false

    var body: some View {
        ZStack {
            VStack {
                Button("Buy Crypto") {
                    if !showMeso {
                        showMeso.toggle()
                    }
                }
            }

            if showMeso {
                // Calling `meso.transfer` will render the WebView
                meso.transfer()
            }
        }
    }
}

You can close the Meso WebView at any time by calling meso.destroy().

Reference

For a detailed reference, view the meso-js docs.

MesoTransferConfiguration

The MesoTransferConfiguration struct is located in Meso.swift.

Network

A CAIP-2 network identifier.

_{kind: enum}

• ethereumMainnet: "eip155:1"
• solanaMainnet: "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp"
• polygonMainnet: "eip155:137"

Asset

_{kind: enum}

• sol: Solana
• eth: Ethereum
• usdc: USDC

Environment

_{kind: enum}

AuthenticationStrategy

_{kind: enum}

Events

The meso instance will dispatch events at various points in the lifecycle of a Transfer session.

You can handle these events like so:

meso.on { event in
    switch event {
    case .configurationError(let payload):
        print("[Configuration Error]: \(payload)")
    case .unsupportedAssetError(let payload):
        print("[Unsupported Asset Error]: \(payload)")
    case .unsupportedNetworkError(let payload):
        print("[Unsupported Network Error]: \(payload)")
    case .requestSignedMessage(let payload, let callback):
        // This demonstrates a generic method of signing messages with Solana wallets. In the real world, you would
        // typically use a library or your own signing implementation.
        // If the user cancels or rejects signing, or there is a failure, return nil – `callback(nil)`
        callback(signMessage(messageToSign: payload.messageToSign))
    case .close:
        showMeso = false
    case .transferApproved(let payload):
        print("Handling `transferApproved` \(payload.transfer.id), \(payload.transfer.status)")
    case .transferComplete(let payload):
        let networkTransactionId = payload.transfer.networkTransactionId ?? "unknown"
        print("Transfer complete! mesoId: \(payload.transfer.id), networkTransactionId: \(networkTransactionId)")
        showMeso = false
    default:
        print("Unknown or discarded event")
    }
}

Each event is a MesoEvent and will provide one of the following payloads:

TransferPayload

A wrapped result of a transfer status update to be sent to the partner application.

| Properties | Description | | transfer | Transfer |

Transfer

Details of a Meso transfer.

TransferStatus

_{kind: enum}

ErrorPayload

RequestSignedMessagePayload

The payload received when the webView prompts for a wallet signature.

Testing values

In sandbox, you can use the following values for testing:

• transfer configuration
  • sourceAmount
  • "666.66" will cause onboarding to fail due to risk checks and the user will be frozen
  • "666.06" will fail the transfer with the payment being declined
• 2FA (SMS)
  • 000000 will succeed
• Onboarding values
  • Debit Card
  • Number: 5305484748800098
  • CVV: 435
  • Expiration Date: 12/2025
  • Taxpayer ID (last 4 digits of SSN)
  • 0000 will require the user enter a fully valid SSN (you can use 123345432).
  • Any other 4-digit combination will pass

Supported versions

While the example application targets iOS 15+, Meso should work with iOS 13-14.

Caveats

• You will have to implement your own message signing mechanism. For this demo, we have roughed one in for Solana.
• The demo code contains print statements, which you can remove according to your requirements.