Creating a new entity

Check if a lead record exists, by using the first and the last name as constraints:

// Look for Ivan Petrov among Leads
$ivanPetrovId = $client->entities->getNumericID('Leads', [
    'firstname'         => 'Ivan',
    'lastname'          => 'Petrov',
]);

// Add his record if it doesn't exist
if (intval($ivanPetrovId) < 1) {
    $ivanPetrov = $client->entities->createOne('Leads', [
        'salutationtype'    => 'Mr.',
        'firstname'         => 'Ivan',
        'lastname'          => 'Petrov',
        'phone'             => "+7 495 4482237",
        'fax'               => "+7 495 3895096",
        'company'           => "ACME Ltd",
        'email'             => "roga-kopyta.ru",
        'leadsource'        => "Trade Show",
        'website'           => "roga-kopyta.ru",
        'leadstatus'        => "Cold",
    ]);
    print_r($ivanPetrov);
} else {
    echo('Ivan Petrov\'s record already exists!' . PHP_EOL);
}

// The output
Array
(
    [salutationtype] => Mr.
    [firstname] => Ivan
    [lead_no] => LEA4
    [phone] => +7 495 4482237
    [lastname] => Petrov
    [mobile] =>
    [company] => ACME Ltd
    [fax] => +7 495 3895096
    [email] => roga-kopyta.ru
    [leadsource] => Trade Show
    [website] => roga-kopyta.ru
    [leadstatus] => Cold
    [annualrevenue] => 0.00000000
    ...
    [id] => 10x9
)