Resolution is a library for interacting with blockchain domain names. It can be used to retrieve payment addresses, IPFS hashes for decentralized websites, and GunDB usernames for decentralized chat.

Resolution is primarily built and maintained by Unstoppable Domains.

Resoultion supports decentralized domains across two main zones:

• Crypto Name Service (uns)
  • .crypto
  • .coin
  • .wallet
  • .bitcoin
  • .blockchain
  • .x
  • .888
  • .nft
  • .dao
• Zilliqa Name Service (zns)
  • .zil

pod 'UnstoppableDomainsResolution', '~> 4.0.0'

package.dependencies.append(
    .package(url: "https://github.com/unstoppabledomains/resolution-swift", from: "4.0.0")
)

• Create an instance of the Resolution class
• Call any method of the Resolution class asyncronously

NOTE: make sure an instance of the Resolution class is not deallocated until the asyncronous call brings in the result. Your code is the only owner of the instance so keep it as long as you need it.

import UnstoppableDomainsResolution

guard let resolution = try? Resolution() else {
  print ("Init of Resolution instance with default parameters failed...")
  return
}

Version 0.3.0 introduced the Configurations struct that is used for configuring each connected naming service. Library can offer three naming services at the moment:

• uns resolves .crypto , .coin, .wallet, .bitcoin, .blockchain, .x, .888, .nft, .dao domains,
• zns resolves .zil domains

By default, each of them is using the mainnet network via infura provider. Unstoppable domains are using the infura key with no restriction for UNS.

You can update each naming service separately

let resolution = try Resolution(configs: Configurations(
        uns: UnsLocations = UnsLocations(
            layer1: NamingServiceConfig(
                providerUrl: "https://mainnet.infura.io/v3/3c25f57353234b1b853e9861050f4817",
                network: "mainnet"),
            layer2: NamingServiceConfig(
                providerUrl: "https://polygon-mainnet.infura.io/v3/3c25f57353234b1b853e9861050f4817",
                network: "polygon-mainnet")
        ),
        zns: NamingServiceConfig = NamingServiceConfig(
            providerUrl: "https://api.zilliqa.com",
            network: "mainnet")
    )
);

// domain udtestdev-creek.crypto exists only on the rinkeby network.

resolution.addr(domain: "udtestdev-creek.crypto", ticker: "eth") { (result) in
    switch result {
    case .success(let returnValue):
        ethAddress = returnValue
        domainReceived.fulfill()
    case .failure(let error):
        XCTFail("Expected Eth Address, but got \(error)")
    }
}

Version 0.1.3 introduced the batchOwners(domains: _, completion: _ ) method which adds additional convenience when making multiple domain owner queries.

This method is only compatible with uns-based domains. Using this method with any other domain type will throw the error: ResolutionError.methodNotSupported.

As opposed to the single owner(domain: _, completion: _) method, this batch request will return an array of owners [String?]. If the the domain is not registered or its value is null, the corresponding array element of the response will be nil without throwing an error.

resolution.batchOwners(domains: ["brad.crypto", "otherbrad.crypto"]) { result in
  switch result {
  case .success(let returnValue):
    // returnValue: [String: String?] = <map of domains to owner address>
    let domainOwner = returnValue
  case .failure(let error):
    XCTFail("Expected owner, but got \(error)")
  }
}

Make sure your app has AppTransportSecurity settings to allow HTTP access to the https://main-rpc.linkpool.io domain.

By default, this library uses the native iOS networking API to connect to the internet. If you want the library to use your own networking layer instead, you must conform your networking layer to the NetworkingLayer protocol. This protocol requires only one method to be implemented: makeHttpPostRequest(url:, httpMethod:, httpHeaderContentType:, httpBody:, completion:). Using this method will bypass the default behavior and delegate the request to your own networking code.

For example, construct the Resolution instance like so:

guard let resolution = try? Resolution(networking: MyNetworkingApi) else {
  print ("Init of Resolution instance failed...")
  return
}

If the domain you are attempting to resolve is not registered or doesn't contain the information you are requesting, this framework will return a ResolutionError with the possible causes below. We advise creating customized errors in your app based on the return value of the error.

enum ResolutionError: Error {
  case unregisteredDomain
  case unsupportedDomain
  case recordNotFound
  case recordNotSupported
  case unsupportedNetwork
  case unspecifiedResolver
  case unknownError(Error)
  case proxyReaderNonInitialized
  case inconsistentDomainArray
  case methodNotSupported
}

Contributions to this library are more than welcome. The easiest way to contribute is through GitHub issues and pull requests.

Once your app has a working Unstoppable Domains integration, register it here. Registered apps appear on the Unstoppable Domains homepage and Applications page — putting your app in front of tens of thousands of potential customers per day.

Also, every week we select a newly-integrated app to feature in the Unstoppable Update newsletter. This newsletter is delivered to straight into the inbox of ~100,000 crypto fanatics — all of whom could be new customers to grow your business.

Join our discord community and ask questions.