Webservice filter magento products

Hello, I'm working on a webservice that lists all products in my store and would like to set a filter that returns only the products that have qtde in stock, how can I do that?

below are my codes of how I'm doing:

$sessionId = $client->login('username','api_key');  
$funcoes = $client->resources($sessionId);
$result = $client->call($sessionId, 'catalog_product.list');

I need some filter to return only the products they have in stock, thank you.