Examples

Real-world examples of using @layered/dns-records

Explore practical examples demonstrating different use cases for DNS record lookups.

Getting specific record types

Retrieve DNS records by type for any domain.

A records

import { type DnsRecord, getDnsRecords } from '@layered/dns-records'

const domain = 'apple.com'

const aRecords: DnsRecord[] = await getDnsRecords(domain, 'A')

console.log(`A records for ${domain}`)
console.log(aRecords)

Verifying DNS records

Check for specific DNS record values, such as SPF records for email authentication.

import { type DnsRecord, getDnsRecords } from '@layered/dns-records'

const domain = 'example.com'

const txtRecords: DnsRecord[] = await getDnsRecords(domain, 'TXT')

console.log(`${txtRecords.length} TXT records found for ${domain}`)
console.log(txtRecords)

const txtSpfRecord = txtRecords.find(r => r.data.includes('v=spf1'))

console.log(`SPF record:`, txtSpfRecord ? '✅ found' : '❌ not found')

Use the find() method to locate specific records by their data content, such as SPF, DKIM, or DMARC records.

Getting all DNS records

Discover all DNS records for a domain with a single function call.

Basic usage

import { type DnsRecord, getAllDnsRecords } from '@layered/dns-records'

const allDnsRecords: DnsRecord[] = await getAllDnsRecords('example.com')

console.log(allDnsRecords)
console.log(allDnsRecords.length)

The getAllDnsRecords() function automatically discovers subdomains and detects wildcard records.

Using different DNS resolvers

Specify which DNS resolver to use for queries.

import { DnsRecord, getAllDnsRecords } from '@layered/dns-records'

const domain = 'render.com'

const dnsRecords = await getAllDnsRecords(domain, {
  resolver: 'node-dig',
})

console.log(dnsRecords)
console.log(`${dnsRecords.length} DNS Records found ${domain} 👆`)

Available DNS resolvers

Name	Runtime compatibility	Notes
cloudflare-dns	Works on all	Requires fetch as global
google-dns	Works on all	Requires fetch as global
node-dns	Works only in Node.js	Uses Node.js DNS module
node-dig	Works only in Node.js	Uses dig command
deno-dns	Works only in Deno	Uses Deno.resolveDns

Streaming DNS records

Process DNS records as they’re discovered using the streaming API.

import { type DnsRecord, getAllDnsRecordsStream, parseDnsRecord } from '@layered/dns-records'

// get the DNS Records stream. Notice await is not needed
const dnsRecordsStream = getAllDnsRecordsStream('shopify.com')

// decoder to convert the Uint8Array to a string
const decoder = new TextDecoder()

for await (const record of dnsRecordsStream) {
  // record is a Uint8Array, so we need to convert it to a string
  const dnsRecordLine = decoder.decode(record)
  console.log('DNS line', dnsRecordLine)

  // parse the DNS record line to a DnsRecord object
  const dnsRecord: DnsRecord = parseDnsRecord(dnsRecordLine)
  //console.log('DNS object', dnsRecord)
}

Use streaming when you need to process records immediately as they’re discovered, rather than waiting for all records to be retrieved.

Advanced options

Customize subdomain discovery with additional options.

import { getAllDnsRecords } from '@layered/dns-records'

const allRecords = await getAllDnsRecords('x.com', {
  resolver: 'cloudflare-dns',
  commonSubdomainsCheck: true,
  subdomains: ['extra-subdomain-to-check-for'],
})

console.log('DNS all records', allRecords)

Options explained

• resolver - Which DNS resolver to use (defaults to best for current runtime)
• commonSubdomainsCheck - Check for common subdomains like www, api, mail (default: true)
• subdomains - Additional subdomains to check beyond the common ones