Aşağıdaki kodları wordpress kurulu olan root dizinine customFeed.php olarak kaydedin:

<?php
	define('WP_USE_THEMES', false);
	require('./wp-blog-header.php');

	$num = $_GET["numberposts"] ?: '10';
	$cat = $_GET["catid"];
	$postID = $_GET["postid"];
	$type = $_GET["type"];

	switch ($type){
	   case "singlePost":
		  $posts = get_posts('p='.$postID.'&numberposts=1');
		  break;
	   case "catFeed":
		  $posts = get_posts('category='.$cat.'&numberposts='.$num.'&order=ASC');
		  break;
	   default:
		  $posts = get_posts('numberposts='.$num.'&order=ASC');
	}
?>
<xml>
	<items>
      <?php if($type == "catFeed"){ ?>
         <catname><?php echo get_cat_name($cat); ?></catname>
         <catdescription><?php echo category_description($cat); ?></catdescription>
      <?php } ?>
      <?php foreach ($posts as $post) : start_wp(); ?>
         <item>
            <id><?php the_id();?></id>
            <title><![CDATA[<?php the_title();?>]]></title>
            <link><?php the_permalink_rss() ?></link>
            <author><?php the_author();?></author>
            <pubDate><?php the_date();?></pubDate>
            <teaser><![CDATA[<?php the_excerpt();?>]]></teaser>
            <?php if($type == "singlePost"){ ?>
               <content><![CDATA[<?php the_content();?>]]></content>
            <?php } ?>
         </item>
      <?php endforeach; ?>
   </items>
</xml>

Kullanımı:

http://www.siteadi.com/customFeed.php?catid=1&type=catFeed&numberposts=20

http://www.siteadi.com/customFeed.php?postid=4&type=singlePost