Welcome to your quick start guide for using web3.swift, an Ethereum API for Swift. In this article, we’ll walk through the steps of installation, usage, and troubleshoot common issues. Let’s dive in!

Installation

To get started with web3.swift, you have two primary options for installation: Swift Package Manager or CocoaPods (though the latter is not recommended). Here are the steps for each:

Swift Package Manager

Using Xcode, add the repository to your project by navigating to File – Swift Packages. Alternatively, you can add the following line to your Package.swift file:

swift.package(url: "https://github.com/argentlabs/web3.swift", from: "1.1.0")

CocoaPods (Not Recommended)

If you prefer CocoaPods, add the following line to your Podfile:

pod 'web3.swift'

Then, run the following command in your terminal:

$ pod install

Usage

Once installed, you can start interacting with the Ethereum network. Here’s how to get started:

Creating an Ethereum Account

First, you need to create an instance of EthereumAccount with a key storage provider:

import web3

// Recommended: Implement your own KeyStorage provider instead of using EthereumKeyLocalStorage in production.
let keyStorage = EthereumKeyLocalStorage()
let account = try? EthereumAccount.create(replacing: keyStorage, keystorePassword: MY_PASSWORD)

Connecting to the Ethereum Network

You can connect using either EthereumHttpClient or EthereumWebSocketClient. This will give you access to various functions for interacting with the blockchain:

guard let clientUrl = URL(string: "https://an-infura-or-similar-url.com/123") else { return }
let client = EthereumHttpClient(url: clientUrl)
// Or for WebSocket
guard let clientUrl = URL(string: "wss://sepolia.infura.io/ws/v3/123") else { return }
let client = EthereumWebSocketClient(url: clientUrl)

Getting the Current Gas Price

To get the current gas price, you can use the following code snippet:

client.eth_gasPrice { (error, currentPrice) in
    print("The current gas price is \(currentPrice)")
}

If you’re using async/await, you can await the results:

let gasPrice = try await client.eth_gasPrice()

Working with Smart Contracts

Let’s think of interacting with smart contracts like sending a letter with a specific set of instructions to a mailbox. You write the letter (the transaction), include the address (the smart contract), and the postman (the Ethereum network) delivers it. Here’s how you can encode a smart contract function:

public struct Transfer: ABIFunction {
    public static let name = "transfer"
    public let gasPrice: BigUInt? = nil
    public let gasLimit: BigUInt? = nil
    public var contract: EthereumAddress
    public let from: EthereumAddress?
    public let to: EthereumAddress
    public let value: BigUInt

    public init(contract: EthereumAddress, from: EthereumAddress? = nil, to: EthereumAddress, value: BigUInt) {
        self.contract = contract
        self.from = from
        self.to = to
        self.value = value
    }

    public func encode(to encoder: ABIFunctionEncoder) throws {
        try encoder.encode(to)
        try encoder.encode(value)
    }
}

In this example, the various properties like contract, from, and to represent the recipient addresses and the value to be transferred. Subsequently, the function can be used to generate and send a contract call.

Troubleshooting Tips

If you run into issues while setting up or using web3.swift, here are some troubleshooting ideas:

• Check if the URL used for the EthereumHttpClient or EthereumWebSocketClient is correct and properly formatted.
• Ensure that you are using the correct versions of dependencies listed in the README.
• If you encounter issues with encoding or decoding transactions, ensure that the data types match the expected formats.

For more insights, updates, or to collaborate on AI development projects, stay connected with fxis.ai.

Conclusion

At fxis.ai, we believe that such advancements are crucial for the future of AI, as they enable more comprehensive and effective solutions. Our team is continually exploring new methodologies to push the envelope in artificial intelligence, ensuring that our clients benefit from the latest technological innovations.

Happy coding with web3.swift! Dive into your Ethereum journey and leverage the power of decentralized finance.