• Installing Resolution
• Updating Resolution
• Using Resolution
• Error Handling
• Development
• Free advertising for integrated apps

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

Resolution is primarily built and maintained by Unstoppable Domains.

Resolution supports different decentralized domains. Please, refer to the Top Level Domains List

For more information, see our detailed API Reference.

Resolution can be installed with either yarn or npm.

yarn add @unstoppabledomains/resolution

npm install @unstoppabledomains/resolution --save

If you're interested in resolving domains via the command line, see our CLI section.

Resolution can be updated with either yarn or npm.

yarn upgrade @unstoppabledomains/resolution --latest

npm update @unstoppabledomains/resolution --save

const {default: Resolution} = require('@unstoppabledomains/resolution');

// obtain a key by following this document https://docs.unstoppabledomains.com/domain-distribution-and-management/quickstart/retrieve-an-api-key/#api-key
const resolution = new Resolution({apiKey: '<api_key>'});

NOTE: The apiKey is only used resolve domains from UNS. Behind the scene, it still uses the default ZNS (Zilliqa) RPC url. For additional control, please specify your ZNS configuration.

const {default: Resolution} = require('@unstoppabledomains/resolution');

const resolution = new Resolution({
  apiKey: '<api_key>',
  sourceConfig: {
    zns: {
      url: 'https://api.zilliqa.com',
      network: 'mainnet',
    },
  },
});

You may want to specify a custom provider:

• if you want to use a dedicated blockchain node
• if you want to monitor app usage
• if you already have a provider in your app to re-use it for domain resolution

Default provider can be changed by changing constructor options new Resolution(options) or by using one of the factory methods:

• Resolution.alchemy()
• Resolution.infura()
• Resolution.fromWeb3Version1Provider()
• Resolution.fromEthersProvider()
• etc.

const {default: Resolution} = require('@unstoppabledomains/resolution');

// obtain a key from https://www.infura.io
const resolution = new Resolution({
  sourceConfig: {
    uns: {
      locations: {
        Layer1: {
          url: 'https://mainnet.infura.io/v3/<infura_api_key>',
          network: 'mainnet',
        },
        Layer2: {
          url: 'https://polygon-mainnet.infura.io/v3/<infura_api_key>',
          network: 'polygon-mainnet',
        },
      },
    },
    zns: {
      url: 'https://api.zilliqa.com',
      network: 'mainnet',
    },
    ens: {
      url: 'https://mainnet.infura.io/v3/<infura_api_key>',
      network: 'mainnet',
    },
  },
});

In some scenarios system might not be flexible enough to easy distinguish between various Ethereum testnets at compilation time. In this case, Resolution library provide a special async constructor await Resolution.autonetwork(options). This method makes a JSON RPC "net_version" call to the provider to get the network id.

This method configures only Uns. Zns is supported only on Zilliqa mainnet which is going to be used in any cases. You can provide a configured provider or a blockchain url as in the following example:

await Resolution.autoNetwork({
  uns: {provider},
});

To see all constructor options and factory methods check Unstoppable API reference.

function resolve(domain, currency) {
  resolution
    .addr(domain, currency)
    .then((address) => console.log(domain, 'resolves to', address))
    .catch(console.error);
}

resolve('brad.crypto', 'ETH');
resolve('brad.zil', 'ZIL');
resolve('vitalik.eth', 'ETH');

Create a new file in your project, ipfs_hash.js.

function resolveIpfsHash(domain) {
  resolution
    .ipfsHash(domain)
    .then((hash) =>
      console.log(
        `You can access this website via a public IPFS gateway: https://gateway.ipfs.io/ipfs/${hash}`,
      ),
    )
    .catch(console.error);
}

resolveIpfsHash('homecakes.crypto');
resolveIpfsHash('vitalik.eth');

Create a new file in your project, custom-resolution.js.

// Does not support ENS

function resolveCustomRecord(domain, record) {
  resolution
    .records(domain, [record])
    .then((value) => console.log(`Domain ${domain} ${record} is: ${value}`))
    .catch(console.error);
}

resolveCustomRecord('homecakes.crypto', 'custom.record.value');

This API is used to retrieve wallet address for single address record. (See Cryptocurrency payment section for the record format)

With homecakes.crypto has crypto.ETH.address on-chain:

function getWalletAddr(domain, ticker) {
  resolution
    .addr(domain, ticker)
    .then((address) =>
      console.log(`Domain ${domain} has address for ${ticker}: ${address}`),
    )
    .catch(console.error);
}
getWalletAddr('homecakes.crypto', 'ETH');
// Domain homecakes.crypto has address for ETH: 0xe7474D07fD2FA286e7e0aa23cd107F8379085037
getWalletAddr('vitalik.eth', 'ETH');
// Domain homecakes.crypto has address for ETH: 0xe7474D07fD2FA286e7e0aa23cd107F8379085037

This API is used to retrieve wallet address for multi-chain address records. (See multi-chain currency)

With aaron.x has crypto.AAVE.version.ERC20.address on-chain:

// Does not support ENS

function getMultiChainWalletAddr(domain, ticker, network) {
  resolution
    .multiChainAddr(domain, ticker, network)
    .then((address) =>
      console.log(
        `Domain ${domain} has address for ${ticker} on network ${network}: ${address}`,
      ),
    )
    .catch(console.error);
}
getMultiChainWalletAddr('aaron.x', 'AAVE', 'ETH');
// Domain aaron.x has address for AAVE on network ETH: 0xCD0DAdAb45bAF9a06ce1279D1342EcC3F44845af

This (beta) API can be used to resolve different formats

function getWalletAddress(domain, network, token) {
  resolution
    .getAddress(domain, network, token)
    .then((address) =>
      console.log(
        `Domain ${domain} has address for ${token} on ${network}: ${address}`,
      ),
    )
    .catch(console.error);
}

Resolve single address format (similar to addr API)

With homecakes.crypto has a crypto.ETH.address record set on-chain:

getWalletAddress('homecakes.crypto', 'ETH', 'ETH');
// Domain homecakes.crypto has address for ETH on ETH: 0xe7474D07fD2FA286e7e0aa23cd107F8379085037

Resolve multi-chain currency address format (See multi-chain currency)

With aaron.x has a crypto.AAVE.version.ERC20.address record set to 0xCD0DAdAb45bAF9a06ce1279D1342EcC3F44845af. The ERC20 indicates it's a token on ETH network:

getWalletAddress('aaron.x', 'ETH', 'AAVE');
// Domain aaron.x has address for AAVE on ETH: 0xCD0DAdAb45bAF9a06ce1279D1342EcC3F44845af

Derive wallet addresses within the same blockchain network and blockchain family.

The API can also be used by crypto exchanges to infer wallet addresses. In centralized exchanges, users have same wallet addresses on different networks with same wallet family. (See Blockchain Family, Network, Token Level Addresses section for the record format)

With blockchain-family-keys.x only has token.EVM.address record on-chain. The API resolves to same wallet address for tokens live on EVM compatible networks.

getWalletAddress('blockchain-family-keys.x', 'ETH', 'AAVE');
// Domain blockchain-family-keys.x has address for AAVE on ETH: 0xCD0DAdAb45bAF9a06ce1279D1342EcC3F44845af

getWalletAddress('blockchain-family-keys.x', 'ETH', 'ETH');
// Domain blockchain-family-keys.x has address for ETH on ETH: 0xCD0DAdAb45bAF9a06ce1279D1342EcC3F44845af

getWalletAddress('blockchain-family-keys.x', 'AVAX', 'USDT');
// Domain blockchain-family-keys.x has address for USDT on AVAX: 0xCD0DAdAb45bAF9a06ce1279D1342EcC3F44845af

With uns-devtest-nickshatilo-withdraw-test2.x only has token.EVM.ETH.address record on chain. The API resolves to the same wallet address for tokens specifically on Ethereum network.

getWalletAddress('uns-devtest-nickshatilo-withdraw-test2.x', 'ETH', 'AAVE');
// Domain blockchain-family-keys.x has address for AAVE on ETH: 0xCD0DAdAb45bAF9a06ce1279D1342EcC3F44845af

getWalletAddress('uns-devtest-nickshatilo-withdraw-test2.x', 'ETH', 'MATIC');
// Domain blockchain-family-keys.x has address for ETH on ETH: 0xCD0DAdAb45bAF9a06ce1279D1342EcC3F44845af

getWalletAddress('uns-devtest-nickshatilo-withdraw-test2.x', 'ETH', 'USDT');
// Domain blockchain-family-keys.x has address for USDT on ETH: 0xCD0DAdAb45bAF9a06ce1279D1342EcC3F44845af

getWalletAddress('uns-devtest-nickshatilo-withdraw-test2.x', 'MATIC', 'USDT');
// won't work

The API is compatible with other address formats. If a domain has multiple address formats set, it will follow the algorithm described as follow:

if a domain has following records set:

token.EVM.address
crypto.USDC.version.ERC20.address
token.EVM.ETH.USDC.address
crypto.USDC.address
token.EVM.ETH.address

getAddress(domain, 'ETH', 'USDC') will lookup records in the following order: // Not supported with ENS

1. token.EVM.ETH.USDC.address
2. crypto.USDC.address
3. crypto.USDC.version.ERC20.address
4. token.EVM.ETH.address
5. token.EVM.address

When resolution encounters an error it returns the error code instead of stopping the process. Keep an eye out for return values like RECORD_NOT_FOUND.

Use these commands to set up a local development environment (macOS Terminal or Linux shell).

1. Recommended NodeJs version

• Node v16

2. Clone the repository

   git clone https://github.com/unstoppabledomains/resolution.git
   cd resolution

3. Install dependencies

   yarn install

   or

   npm install

• Network config: $ yarn network-config:pull
• Resolver keys: $ yarn resolver-keys:pull
• Both configs: $ yarn config:pull

Resolution library relies on environment variables to load TestNet RPC Urls. This way, our keys don't expose directly to the code. These environment variables are:

• L1_TEST_NET_RPC_URL
• L1_TEST_NET_RPC_WSS_URL
• L2_TEST_NET_RPC_URL
• L2_TEST_NET_RPC_WSS_URL

In order to validate the code change, copy .env.example file change the name to .env. Then, update the values of variables.

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.

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