composer require mailpass/mailpass-php

<?php
use MailPass\Client;

$client = new Client('mp_live_your_api_key_here');

// Send OTP
$response = $client->otp->send([
    'email' => 'user@example.com',
    'purpose' => 'login',
]);
echo $response['request_id'];

// Verify OTP
$result = $client->otp->verify([
    'request_id' => $response['request_id'],
    'otp' => '123456',
]);

if ($result['success']) {
    echo 'Verified! ' . $result['email'];
}

// List subscribers
$subscribers = $client->subscribers->list([
    'list_id' => 1,
    'page' => 1,
    'per_page' => 20,
]);
foreach ($subscribers['data'] as $sub) {
    echo $sub['email'] . ' ' . $sub['status'] . "\n";
}

// Create subscriber
$newSub = $client->subscribers->create([
    'email' => 'new@example.com',
    'name' => 'Jane Doe',
    'list_id' => 1,
    'tags' => ['newsletter'],
    'double_optin' => true,
]);
echo $newSub['data']['uuid'];

use MailPass\Exception\ApiException;
use MailPass\Exception\ValidationException;
use MailPass\Exception\RateLimitException;

try {
    $response = $client->otp->send(['email' => 'user@example.com']);
} catch (ValidationException $e) {
    echo "Validation: " . $e->getMessage() . "\n";
    print_r($e->getDetails());
} catch (RateLimitException $e) {
    echo "Rate limited. Retry after " . $e->getRetryAfter() . "s\n";
} catch (ApiException $e) {
    echo "API error [{$e->getErrorCode()}]: {$e->getMessage()}\n";
}