config/form.default.php
<?php
add_action("init", function() {
$form_id = "default";
$args = array();
$args['wp_query'] = array('post_type' => array('post'), 'posts_per_page' => 10);
$args['config']['meta_key_relation'] = 'AND';
$args['config']['taxonomy_relation'] = 'AND';
$args['fields'][] = array(
'type' => 'search',
'label' => 'Search'
);
$args['fields'][] = array(
'type' => 'taxonomy',
'label' => 'Category',
'taxonomy' => 'category',
'format' => 'select',
'allow_null' => true,
'operator' => 'AND'
);
$args['fields'][] = array(
'type' => 'submit',
'value' => 'Submit'
);
register_wpas_form($form_id, $args);
});