Reverse Lookups

In web2, reverse DNS lookup or reverse DNS resolution (rDNS), is a querying technique of the Domain Name System (DNS) to determine the domain name associated with an IP address.

For web3 dapps, like ArchID reverse lookup is a query that uses an Archway address to return a list of non-expired ArchID domains that resolve to it.

Reverse lookups are handled by the ResolveAddress query entry point. ResolveAddress takes a parameter (address) as an argument.

Here's an example of how we might query the ResolveAddress entry point.

async function resolveAddress(address = null) {
  if (!address) return;
  let client = await getClient();
  try {
    let entrypoint = {
      resolve_address: {
        address: address
      }
    };
    let query = await client.queryClient.wasm.queryContractSmart(
      REGISTRY_CONTRACT,
      entrypoint
    );
    return query;
  } catch(e) {
    return {error: e};
  }
}

Here's what the response for ResolveAddress looks like for an address that has one, or more, domains resolving to it.

{ "names": [ "archid.arch" ] }

If no domains resolve to the queried address, ResolveAddress responds with an empty array.

{ "names": [] }

tip

ResolveAddress is useful for builders to identify their users and show personalized profiles. See the Name Resolution doc for information about showing avatars, and user customized domain data.