gistfile1.txt

add_filter( 'wo_endpoints', 'wo_extend_endpoints' );
function wo_extend_endpoints ( $endpoints ){
	$endpoints = array(
		'is_logged_in' => array(
			'func' => '_wo_is_logged_in_wo7391', 
			'public' => false 
		)
	);

	return $endpoints;
}

function _wo_is_logged_in_wo7391( $token = null ){
	if ( !isset( $token['access_token'] ) ) {
		$response = new OAuth2\Response();
		$response->setError( 400, 'invalid_request', 'Missing access token' );
		$response->send();
		exit;
	}

	$access_token = $token['access_token'];

	global $wpdb;
	$stmt = $wpdb->get_row("SELECT expires FROM {$wpdb->prefix}oauth_access_tokens WHERE access_token={$access_token}");
	
	// Check the expires time against the current time and return if the token is valid or not.
	
	exit;	
}