Building a Custom Registrar Integration

The Domain Seller addon uses an Integration Registry pattern. Each registrar is a PHP class that implements Domain_Selling_Capability and registers itself via the wu_domain_seller_register_capabilities action hook.

This guide shows how to wire in a custom registrar.

The interface

Your class must implement WP_Ultimo\Integrations\Capabilities\Domain_Selling_Capability and extend WP_Ultimo\Integrations\Base_Capability_Module.

Required methods:

namespace My\Plugin\Capabilities;

use WP_Ultimo\Integrations\Base_Capability_Module;
use WP_Ultimo\Integrations\Capabilities\Domain_Selling_Capability;

class My_Registrar_Selling extends Base_Capability_Module implements Domain_Selling_Capability {

    // --- Required identity methods (from Base_Capability_Module) ---

    public function get_capability_id(): string {
        return 'domain-selling';  // always 'domain-selling'
    }

    public function get_title(): string {
        return __('Domain Selling', 'my-plugin');
    }

    public function get_explainer_lines(): array {
        return [
            'will'     => [__('Enable domain registration via My Registrar.', 'my-plugin')],
            'will_not' => [],
        ];
    }

    // --- Core required methods (from Domain_Selling_Capability) ---

    /** Pull all available TLDs and wholesale pricing. */
    public function sync_tlds(): array { ... }

    /** Check availability of $domain_name across $tlds. */
    public function search_domains(string $domain_name, array $tlds = []): array { ... }

    /** Get wholesale price for a TLD for N years. */
    public function get_domain_pricing(string $tld, int $years = 1): array { ... }

    /** Register a domain. Returns ['success' => true, 'expiry_date' => '...'] on success. */
    public function register_domain(string $domain_name, array $registrant_info, int $years = 1): array { ... }

    /** Renew a domain for N years. */
    public function renew_domain(string $domain_name, int $years = 1): array { ... }

    /** Get registration status, expiry date, nameservers. */
    public function get_domain_info(string $domain_name): array { ... }

    /** Test API credentials and connectivity. */
    public function test_connection(): array { ... }
}

Optional methods

Implement these to unlock additional features. The addon detects support via method_exists():

Method	Unlocks
supports_whois_privacy(): bool	WHOIS privacy option in product settings
enable_whois_privacy(string $domain_name): array	Auto-enables privacy at registration
get_dns_records(string $domain_name): array	Customer DNS view tab
add_dns_record(string $domain_name, array $record_data): array	Customer can add DNS records
update_dns_record(string $domain, string $record_id, array $record_data): array	Customer can edit DNS records
delete_dns_record(string $domain, string $record_id, array $data): array	Customer can delete DNS records
update_nameservers(string $domain_name, array $nameservers): array	Nameserver management
get_epp_code(string $domain_name): array	Domain transfer (outgoing)
transfer_domain(string $domain, string $auth_code, array $registrant_info, array $options): array	Domain transfer (incoming)

Return value convention

All methods return an array with at minimum a success key:

// Success
return ['success' => true, 'data' => [...]];

// Failure
return ['success' => false, 'message' => 'Human-readable error'];

---

Registering your capability

Register your class using the wu_domain_seller_register_capabilities action:

add_action('wu_domain_seller_register_capabilities', function(\WP_Ultimo\Integrations\Integration_Registry $registry) {
    $registry->add_capability('my-registrar', new \My\Plugin\Capabilities\My_Registrar_Selling());
});

The first argument to add_capability() is the provider ID — a lowercase slug used to identify your registrar in settings, product configuration, and log channels. Use something unique (e.g., your company slug).

---

Adding credential fields to the wizard

To let admins enter credentials through the setup wizard, register your integration:

add_action('wu_domain_seller_register_integrations', function(\WP_Ultimo\Integrations\Integration_Registry $registry) {
    $registry->add_integration('my-registrar', [
        'name'   => __('My Registrar', 'my-plugin'),
        'fields' => [
            [
                'id'    => 'my_registrar_api_key',
                'label' => __('API Key', 'my-plugin'),
                'type'  => 'text',
            ],
            [
                'id'    => 'my_registrar_api_secret',
                'label' => __('API Secret', 'my-plugin'),
                'type'  => 'password',
            ],
        ],
    ]);
});

Credentials are stored as network options using the field IDs as keys. Retrieve them in your capability class with wu_get_setting('my_registrar_api_key').

---

Hooks for post-registration actions

Use these actions to trigger webhooks, provisioning, notifications, or CRM updates:

// After successful domain registration
add_action('wu_domain_registration_completed', function($payment, $registration_data, $result) {
    // $registration_data: domain_name, provider_id, years, expiry_date, customer_id
    // $result: raw registrar response
    my_crm_update_domain($registration_data['domain_name'], $registration_data['customer_id']);
}, 10, 3);

// After registration failure
add_action('wu_domain_registration_failed', function($payment, $registration_data, $error_message) {
    my_alert_team("Domain registration failed: {$registration_data['domain_name']} — {$error_message}");
}, 10, 3);

// After successful renewal
add_action('wu_domain_renewal_completed', function($payment, $renewal_data, $result) {
    // Update your billing system, send a receipt, etc.
}, 10, 3);

// After renewal failure
add_action('wu_domain_renewal_failed', function($payment, $renewal_data, $error_message) {
    // Alert, retry logic, etc.
}, 10, 3);

// After domain transfer completes
add_action('wu_domain_transfer_completed', function($domain, $transfer_data) {
    // $domain is a WP_Ultimo\Models\Domain object
}, 10, 2);

// After SES DKIM verification (if SES integration is active)
add_action('wu_domain_ses_verified', function($domain) {
    // $domain is a WP_Ultimo\Models\Domain object
});

---

Logging

Write to your provider-specific log channel using wu_log_add():

wu_log_add('domain-seller-my-registrar', "Registered {$domain_name} successfully", 'info');
wu_log_add('domain-seller-my-registrar', "Registration failed: {$error}", 'error');

Logs appear under Network Admin › Ultimate Multisite › Logs › domain-seller-my-registrar.