Use MetaMask SDK with iOS

Import MetaMask SDK into your native iOS dapp to enable your users to easily connect with their MetaMask Mobile wallet.

Example

See the example iOS dapp in the iOS SDK GitHub repository for advanced use cases.

Prerequisites

• MetaMask Mobile version 7.6.0 or later installed on your target device (that is, a physical device or emulator). You can install MetaMask Mobile from the App Store or clone and compile MetaMask Mobile from source and build to your target device.

• iOS version 14 or later. The SDK supports ios-arm64 (iOS devices) and ios-arm64-simulator (M1 chip simulators). It currently doesn't support ios-ax86_64-simulator (Intel chip simulators).

Steps

1. Install the SDK

CocoaPods

To add the SDK as a CocoaPods dependency to your project, add the following entry to our Podfile:

pod 'metamask-ios-sdk'

Run the following command:

pod install

Swift Package Manager

To add the SDK as a Swift Package Manager (SPM) package to your project, in Xcode, select File > Swift Packages > Add Package Dependency. Enter the URL of the MetaMask iOS SDK repository: https://github.com/MetaMask/metamask-ios-sdk.

Alternatively, you can add the URL directly in your project's package file:

dependencies: [
    .package(
        url: "https://github.com/MetaMask/metamask-ios-sdk",
        from: "0.3.0"
    )
]

2. Import the SDK

Import the SDK by adding the following line to the top of your project file:

import metamask_ios_sdk

3. Connect your dapp

Connect your dapp to MetaMask by adding the following code to your project file:

let appMetadata = AppMetadata(name: "Dub Dapp", url: "https://dubdapp.com")

@ObservedObject var metamaskSDK = MetaMaskSDK.shared(appMetadata)

metamaskSDK.connect()

By default, MetaMask logs three SDK events: connectionRequest, connected, and disconnected. This allows MetaMask to monitor any SDK connection issues. To disable this, set MetaMaskSDK.shared.enableDebug = false or ethereum.enableDebug = false.

4. Call methods

You can now call any JSON-RPC API method using metamaskSDK.request().

Example: Get chain ID

The following example gets the user's chain ID by calling eth_chainId.

let chainIdRequest = EthereumRequest(method: .ethChainId)
let chainId = await metamaskSDK.request(chainIdRequest)

Example: Get account balance

The following example gets the user's account balance by calling eth_getBalance.

// Create parameters
let account = metamaskSDK.account

let parameters: [String] = [
    account, // account to check for balance
    "latest" // "latest", "earliest" or "pending" (optional)
  ]

// Create request
let getBalanceRequest = EthereumRequest(
    method: .ethGetBalance,
    params: parameters)

// Make request
let accountBalance = await metamaskSDK.request(getBalanceRequest)

Example: Send transaction

The following example sends a transaction by calling eth_sendTransaction.

Use a dictionary

If your request parameters make up a simple dictionary of string key-value pairs, you can use the dictionary directly. Note that Any or even AnyHashable types aren't supported, since the type must be explicitly known.

// Create parameters
let account = metamaskSDK.account

let parameters: [String: String] = [
    "to": "0x...", // receiver address
    "from": account, // sender address
    "value": "0x..." // amount
  ]

// Create request
let transactionRequest = EthereumRequest(
    method: .ethSendTransaction,
    params: [parameters] // eth_sendTransaction expects an array parameters object
    )

// Make a transaction request
let transactionResult = await metamaskSDK.request(transactionRequest)

Use a struct

For more complex parameter representations, define and use a struct that conforms to CodableData, that is, a struct that implements the following requirement:

func socketRepresentation() -> NetworkData

The type can then be represented as a socket packet.

struct Transaction: CodableData {
    let to: String
    let from: String
    let value: String
    let data: String?

    init(to: String, from: String, value: String, data: String? = nil) {
        self.to = to
        self.from = from
        self.value = value
        self.data = data
    }

    func socketRepresentation() -> NetworkData {
        [
            "to": to,
            "from": from,
            "value": value,
            "data": data
        ]
    }
}

// Create parameters
let account = metamaskSDK.account

let transaction = Transaction(
    to: "0x...", // receiver address
    from: account, // sender address
    value: "0x..." // amount
)

// Create request
let transactionRequest = EthereumRequest(
    method: .ethSendTransaction,
    params: [transaction] // eth_sendTransaction expects an array parameters object
    )

// Make a transaction request
let result = await metamaskSDK.request(transactionRequest)