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Getting Started with ResolverOne

Get IP Geolocation data over DNS in under 5 minutes. No APIs, no auth tokens, no HTTP overhead.

What is ResolverOne?​

ResolverOne delivers IP geolocation data through DNS TXT records. Query 8.8.8.8.rslvr.one and get back structured location data about that IP address.

Perfect for:

  • 🤖 IoT devices with limited connectivity
  • 🛰️ Satellite and edge computing
  • ⚡ Low-latency applications
  • 🔋 Battery-powered devices
  • 🌐 Any system that can do DNS (spoiler: that's everything)

Quick Test​

Try this right now in your terminal:

# Standard query (via your ISP's DNS)
dig TXT 8.8.8.8.rslvr.one

# Direct query (recommended - faster & more reliable)
dig TXT 8.8.8.8.rslvr.one @rslvr.one

You'll get back something like:

"US|United States|North America|NA|AS15169|Google LLC|google.com"

Pro tip: Use @rslvr.one for direct queries to our nameservers for faster, more reliable responses under certain network conditions.

No registration, API keys, or complex setup required.

What You Get​

Each response contains pipe-separated values:

country_code|country|continent|continent_code|asn|as_name|as_domain

For example:

  • US = Country code (ISO 3166-1 alpha-2)
  • United States = Full country name
  • North America = Continent
  • NA = Continent code
  • AS15169 = Autonomous System Number
  • Google LLC = AS organization name
  • google.com = AS domain

Your First Integration​

Command Line​

# Basic query (recursive)
dig TXT 1.1.1.1.rslvr.one +short

# Direct query (recommended - faster)
dig TXT 1.1.1.1.rslvr.one @rslvr.one +short

# Use TCP for unreliable networks
dig TXT 1.1.1.1.rslvr.one @rslvr.one +tcp

# Get your own IP's info
dig TXT $(curl -s ifconfig.me).rslvr.one @rslvr.one +short

Python​

# /// script
# dependencies = [
#   "dnspython>=2.0.0",
# ]
# ///

import dns.resolver

def get_location(ip, use_direct=True):
    if use_direct:
        # Direct query to our nameservers (recommended)
        resolver = dns.resolver.Resolver()
        # Resolve rslvr.one A records to get our nameserver IPs
        resolver.nameservers = [str(ip) for ip in dns.resolver.resolve('rslvr.one', 'A')]
        result = resolver.resolve(f"{ip}.rslvr.one", 'TXT')
    else:
        # Standard recursive query
        result = dns.resolver.resolve(f"{ip}.rslvr.one", 'TXT')

    return str(result[0]).strip('"')

# Usage (direct query - faster)
location = get_location("8.8.8.8")
print(location)  # "US|United States|North America|NA|AS15169|Google LLC|google.com"

# Compare performance
import time
start = time.time()
get_location("8.8.8.8", use_direct=True)
direct_time = time.time() - start

start = time.time()
get_location("8.8.8.8", use_direct=False)
recursive_time = time.time() - start

print(f"Direct: {direct_time:.3f}s, Recursive: {recursive_time:.3f}s")

JavaScript (Node.js)​

const dns = require('dns').promises;

async function getLocation(ip, useDirect = true) {
    if (useDirect) {
        // Direct query to our nameservers (recommended)
        const resolver = new dns.Resolver();
        // Resolve rslvr.one A records to get our nameserver IPs
        const nameservers = await dns.resolve4('rslvr.one');
        resolver.setServers(nameservers);
        const records = await resolver.resolveTxt(`${ip}.rslvr.one`);
        return records[0][0];
    } else {
        // Standard recursive query
        const records = await dns.resolveTxt(`${ip}.rslvr.one`);
        return records[0][0];
    }
}

// Usage (direct query - faster)
getLocation('8.8.8.8').then(console.log);

// Compare performance
async function comparePerformance() {
    const start1 = Date.now();
    await getLocation('8.8.8.8', true);
    const directTime = Date.now() - start1;

    const start2 = Date.now();
    await getLocation('8.8.8.8', false);
    const recursiveTime = Date.now() - start2;

    console.log(`Direct: ${directTime}ms, Recursive: ${recursiveTime}ms`);
}

comparePerformance();

Why DNS Instead of HTTP?​

DNS (ResolverOne)Traditional HTTP API
50-200 bytes1KB+ response
Works everywhereNeeds HTTP stack
No auth requiredAPI keys, tokens
Sub-second latencySSL handshake overhead
Battery friendlyPower hungry
Built-in cachingCustom caching

Common Use Cases​

1. Device Location Awareness​

# Your IoT device determines its region
LOCATION=$(dig TXT $(curl -s ifconfig.me).rslvr.one +short)
COUNTRY=$(echo $LOCATION | cut -d'|' -f1)

if [ "$COUNTRY" = "US" ]; then
    echo "US compliance mode activated"
fi

2. Simple Fraud Detection​

# /// script
# dependencies = [
#   "dnspython>=2.0.0",
# ]
# ///

def is_suspicious_ip(ip):
    location = get_location(ip)
    country = location.split('|')[0]

    # Block certain regions
    blocked_countries = ['CN', 'RU', 'KP']
    return country in blocked_countries

3. Content Localization​

async function getTimeZone(ip) {
    const location = await getLocation(ip);
    const continent = location.split('|')[2];

    const timezones = {
        'North America': 'America/New_York',
        'Europe': 'Europe/London',
        'Asia': 'Asia/Tokyo'
    };

    return timezones[continent] || 'UTC';
}

Next Steps​

Launch Tier​

  • Unlimited queries during launch phase
  • No rate limiting
  • No registration required

See our pricing page for details.

Questions?​

Ready to get started? Run your first query now.