xmrmemes/app/Rules/ValidateAddress.php

<?php

namespace App\Rules;

use Illuminate\Contracts\Validation\Rule;
use MoneroIntegrations\MoneroPhp\walletRPC;

class ValidateAddress implements Rule
{
    /**
     * Create a new rule instance.
     *
     * @return void
     */
    public function __construct()
    {
        //
    }

    /**
     * Determine if the validation rule passes.
     *
     * @param  string  $attribute
     * @param  mixed  $value
     * @return bool
     */
    public function passes($attribute, $value)
    {
        $walletRPC = new walletRPC('127.0.0.1', config('app.xmr_network_port')); // Change to match your wallet (monero-wallet-rpc) IP address and port; 18083 is the customary port for mainnet, 28083 for testnet, 38083 for stagenet
        $open_wallet = $walletRPC->open_wallet(config('app.xmr_wallet_name'), '');
        $validate_address = $walletRPC->validate_address($value);
        return $validate_address['valid'];
    }

    /**
     * Get the validation error message.
     *
     * @return string
     */
    public function message()
    {
        return 'The Monero address is not valid.';
    }
}