example-hook.php

<?php

/* place in theme's functions.php file */
/* disable json api if api key not correct */
add_action('init','json_api_apikey_check' , 1 );
function json_api_apikey_check()
{
	$api_key = 'hello';
	$base = get_option('json_api_base', 'api');
	$this_url = "http://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";
	

	if ( ( isset($_REQUEST['json'] ) || strstr($this_url , $base.'/') ) && ( !isset($_REQUEST['apikey']) || $_REQUEST['apikey'] != $api_key ) )
	{

		print "[error:99] Permission denied!";
		exit;
	}
}