rdapapi-php

Official PHP SDK for the RDAP API — look up domains, IP addresses, ASNs, nameservers, and entities via the RDAP protocol.

Installation

composer require rdapapi/rdapapi-php

Requires PHP 8.2 or later.

Quick Start

<?php

use RdapApi\RdapApi;

$api = new RdapApi('your-api-key');

$domain = $api->domain('google.com');

echo $domain->registrar->name;     // "MarkMonitor Inc."
echo $domain->dates->registered;   // "1997-09-15T04:00:00Z"
echo $domain->dates->expires;      // "2028-09-14T04:00:00Z"
print_r($domain->nameservers);     // ["ns1.google.com", ...]

Usage

Configuration

use RdapApi\RdapApi;

// Default configuration
$api = new RdapApi('your-api-key');

// Custom timeout (in seconds)
$api = new RdapApi('your-api-key', ['timeout' => 10]);

// Custom base URL
$api = new RdapApi('your-api-key', ['base_url' => 'https://custom.api.com/v1']);

Domain Lookup

$domain = $api->domain('example.com');
echo $domain->domain;              // "example.com"
echo $domain->registrar->name;     // Registrar name
echo $domain->registrar->iana_id;  // IANA registrar ID
echo $domain->dnssec;              // true/false

// With registrar follow-through (for thin registries)
$domain = $api->domain('example.com', ['follow' => true]);
echo $domain->meta->followed;      // true

IP Address Lookup

$ip = $api->ip('8.8.8.8');
echo $ip->name;            // "LVLT-GOGL-8-8-8"
echo $ip->country;         // "US"
print_r($ip->cidr);        // ["8.8.8.0/24"]
echo $ip->start_address;   // "8.8.8.0"
echo $ip->end_address;     // "8.8.8.255"

ASN Lookup

$asn = $api->asn(15169);           // integer
$asn = $api->asn('AS15169');       // string with prefix (stripped automatically)

echo $asn->name;           // "GOOGLE"
echo $asn->start_autnum;   // 15169

Nameserver Lookup

$ns = $api->nameserver('ns1.google.com');
echo $ns->ldh_name;                // "ns1.google.com"
print_r($ns->ip_addresses->v4);   // ["216.239.32.10"]
print_r($ns->ip_addresses->v6);   // ["2001:4860:4802:32::a"]

Entity Lookup

$entity = $api->entity('GOGL');
echo $entity->name;                    // "Google LLC"
echo $entity->organization;            // "Google LLC"
echo $entity->autnums[0]->handle;     // "AS15169"
echo $entity->networks[0]->cidr[0];   // "8.8.8.0/24"

Bulk Domain Lookup

Requires a Pro or Business plan. Up to 10 domains per call.

$resp = $api->bulkDomains(
    ['google.com', 'github.com', 'example.com'],
    ['follow' => true],
);

echo $resp->summary->total;        // 3
echo $resp->summary->successful;   // 3

foreach ($resp->results as $result) {
    if ($result->status === 'success') {
        echo "{$result->domain} — {$result->data->registrar->name}\n";
    } else {
        echo "{$result->domain} — error: {$result->message}\n";
    }
}

Supported TLDs Catalog

List every TLD the API can resolve, with the date support was added and a qualitative summary of which fields the registry's RDAP server populates. Does not count against your monthly quota.

$tlds = $api->tlds();
if ($tlds !== null) {
    echo "{$tlds->meta->count} TLDs, coverage ".round($tlds->meta->coverage * 100)."%\n";

    foreach ($tlds->data as $tld) {
        $availability = $tld->field_availability;
        if ($availability !== null) {
            echo "{$tld->tld}: expires_at={$availability->expires_at}\n";
        }
    }
}

Filter to recent additions or to a single registry:

$recent = $api->tlds(['since' => '2026-04-01T00:00:00Z']);
$verisign = $api->tlds(['server' => 'rdap.verisign.com']);

Pass back the previous etag to skip the transfer when nothing has changed:

$first = $api->tlds();
$later = $api->tlds(['if_none_match' => $first?->etag ?? '']);
if ($later === null) {
    echo "No change since last poll\n";
}

Look up a single TLD:

$com = $api->tld('com');
echo $com->data->rdap_server_host; // "rdap.verisign.com"

Error Handling

All API errors are thrown as typed exceptions that extend RdapApiException:

use RdapApi\Exceptions\AuthenticationException;
use RdapApi\Exceptions\NotFoundException;
use RdapApi\Exceptions\NotSupportedException;
use RdapApi\Exceptions\RateLimitException;
use RdapApi\Exceptions\SubscriptionRequiredException;

try {
    $domain = $api->domain('example.nope');
} catch (NotSupportedException $e) {
    // Catch before NotFoundException: it's a subclass.
    echo 'The TLD is not covered by RDAP.';
} catch (NotFoundException $e) {
    echo 'The domain is not registered.';
} catch (RateLimitException $e) {
    echo "Rate limited, retry after {$e->retryAfter} seconds";
} catch (AuthenticationException $e) {
    echo 'Invalid API key';
} catch (SubscriptionRequiredException $e) {
    echo 'Subscription required';
}

NotSupportedException extends NotFoundException, so catching NotFoundException still handles both cases.

Exception	HTTP Status	Description
ValidationException	400	Invalid input
AuthenticationException	401	Invalid or missing API key
SubscriptionRequiredException	403	No active subscription
NotFoundException	404	Namespace is covered but no record exists
NotSupportedException	404	Namespace (TLD, IP range, ASN range) is not covered by RDAP
RateLimitException	429	Rate limit or quota exceeded
UpstreamException	502	Upstream RDAP server failure
TemporarilyUnavailableException	503	Domain data temporarily unavailable

All exceptions expose statusCode, errorCode, and getMessage(). RateLimitException and TemporarilyUnavailableException also have retryAfter (int or null).

Nullable Fields

Fields that may be absent in API responses use nullable types (?string, ?int). Check for null before using:

if ($domain->dates->expires !== null) {
    echo "Expires: {$domain->dates->expires}";
}

// Or use PHP 8's nullsafe operator
echo $domain->entities->registrant?->name;

Development

Set up pre-commit hooks (runs lint + tests before each commit):

git config core.hooksPath .githooks

License

MIT — see LICENSE.