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This page details basic installation, configuration, and usage of the JavaScript Resolution Library.


Resolution can be installed with either the yarn or npm command.

yarn add @unstoppabledomains/resolution
npm install @unstoppabledomains/resolution --save

Updating Resolution

Resolution can be updated with either the yarn or npm command.

yarn upgrade @unstoppabledomains/resolution --latest
npm update @unstoppabledomains/resolution --save


Resolution libraries require a connection to the Ethereum network to resolve .crypto and .eth domains. To initialize the library, you need to specify an Ethereum node service provider. Once you create the instance, you can begin resolving domains. Below are examples of how to initialize the library with different providers.

Provider URL

Each of the Resolution Libraries supports an Ethereum provider URL for configuration. You can obtain a provider URL from a service like Alchemy, where getting an API key is free and only requires creating an account.

To choose an alternative Ethereum provider see the Nodes as a Service guide.


Unstoppable libraries use Alchemy as a provider by default without restrictions and rate limits for UNS resolution. Default configuration can be considered production-ready.

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

const ethereumProviderUrl = ALCHEMY_ETHEREUM_API;
const polygonProviderUrl = ALCHEMY_POLYGON_API;

// custom provider config using the `Resolution` constructor options
const resolution = new Resolution({
    sourceConfig: {
      uns: {
        locations: {
          Layer1: {
            url: ethereumProviderUrl,
            network: 'mainnet'
          Layer2: {
            url: polygonProviderUrl,
            network: 'polygon-mainnet',

Make sure to allow eth-mainnet.g.alchemy.com and polygon-mainnet.g.alchemy.com or simply https://*.g.alchemy.com (if using the default configuration) as a connect-src in your Content Security Policy to allow these requests through.

Web3 provider

Connect a web3 provider. You may already have one available in your application from wallets like Metamask and WalletConnect.

import Resolution from "@unstoppabledomains/resolution";

// if web3rovider is attached to window
const web3Provider = window.ethereum;

// if web3Provider.version - 0.x
const resolution = Resolution.fromWeb3Version0Provider(web3Provider);
// or
// if web3Provider.version - 1.x
const resolution = Resolution.fromWeb3Version1Provider(web3Provider);

Ethers provider

Connect a provider from ethers.js

import Resolution from "@unstoppabledomains/resolution";

const resolution = Resolution.fromEthersProvider(ethersProvider);

Error Handling

Unstoppable Domains follows the error handling best practices specific to each library's language. Each error data structure contains an error code, a human-readable message, and extra details that may help you debug the error.

  code: string; // one of our custom error codes
  message?: string; // human-readable error summary
  providerMessage?: string; // internal error message from the provider (alchemy, infura, etc.)
  errorMessage?: string; // internal error message / nested error
  method?: ResolutionMethod; // resolution method (UNS L1, UNS L2, CNS, ZNS, UD API)
  methodName?: string; // resolution method that was used (e.g. Resolution.addr, Resolution.allRecords)
  domain?: string; // domain that caused the error
  currencyTicker?: string; // currency ticker that caused the error
  recordName?: string; // record that caused the error
  namingService?: string; // naming service (UNSL1, UNSL2, ZNS, ENS, CNS, etc.)
  location?: UnsLocation; // domain location (L1, L2)
  tokenUri?: string; // domain metadata link

The code snippet below shows how to handle the common error cases you may encounter during integration, including:

  • Resolving an unregistered domain
  • Resolving an undefined record of a domain
  • Resolving a misconfigured domain
  • Resolving a domain with an unsupported domain ending

We handle the errors thrown by the resolution library by switching on the error code and displaying custom messages to the user. You can then perform other actions to handle the error or show the error message value from the error data structure to the user.

const {default: Resolution} = require('@unstoppabledomains/resolution');
const resolution = new Resolution();
    .addr('domain-with-error.crypto', 'ETH')
    .then((ethAddress) => {
    .catch((error) => {
        if (error.code === 'UnregisteredDomain') {
            console.log('Domain is not registered')
        if (error.code === 'RecordNotFound') {
            console.log('Crypto record is not found (or empty)')
        if (error.code === 'UnspecifiedResolver') {
            console.log('Domain is not configured (empty resolver)')
        if (error.code === 'UnsupportedDomain') {
            console.log('Domain is not supported')

Error Codes

Error Code Description
InconsistentDomainArray Thrown when you attempt to retrieve the locations of multiple domains with different naming services. The location of a domain contains the blockchain, networkId, and valuable metadata like owner, resolver, registry addresses, and provider URL of that domain.
IncorrectResolverInterface Thrown when the domain resolver of the current resolution instance is misconfigured.
InvalidDomainAddress Thrown when you resolve an invalid domain address.
InvalidTwitterVerification Thrown when you resolve the Twitter handle of a domain with an invalid Twitter signature verification.
MetadataEndpointError Thrown when you resolve a domain with an undefined metadata endpoint.
RecordNotFound Thrown when you resolve an undefined record of a domain. For example, resolving the Twitter handle of a domain that doesn't have one.
ServiceProviderError Thrown when you make an invalid request with the current resolution instance configured provider.
UnregisteredDomain Thrown when you resolve a domain not owned by any address.
UnspecifiedCurrency Thrown when the domain you're resolving doesn't have any address of the specified currency.
UnspecifiedResolver Thrown when the domain resolver contract address is not found. For example, the domain doesn't have a specified resolver.
UnsupportedCurrency Thrown when you resolve a domain with a currency not supported by the current resolution instance.
UnsupportedDomain Thrown when you resolve a domain with an ending not supported by the current resolution instance.
UnsupportedService Thrown when using an unsupported naming service with the current resolution instance.
UnsupportedMethod Thrown when you use a method of the current resolution instance not supported by the naming service you're resolving from. For example, using the twitter(), reverse(), getDomainFromTokenId(), locations(), and getTokenuri() methods for the Zilliqa Name Service (ZNS).

Use Case: Retrieve a Domain Record

Retrieve any record of a domain. Applications sometimes set custom records for a domain to use within their application. The code snippet below show how to do this in JavaScript.

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

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

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

Asking For Help

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