Данной функцией можно постить в вп.

function wpPostXMLRPC($title,$body,$rpcurl,$username,
$password,$category,$keywords='',$encoding='UTF-8')
{
$title = htmlentities($title,ENT_NOQUOTES,$encoding);
$keywords = htmlentities($keywords,ENT_NOQUOTES,$encoding);

$content = array(
'title'=>$title,
'description'=>$body,
'mt_allow_comments'=>0,  // 1 to allow comments
'mt_allow_pings'=>0,  // 1 to allow trackbacks
'post_type'=>'post',
'mt_keywords'=>$keywords,
'categories'=>array($category)
);
$params = array(0,$username,$password,$content,true);
$request = xmlrpc_encode_request('metaWeblog.newPost',$params);
$ch = curl_init();
curl_setopt($ch, CURLOPT_POSTFIELDS, $request);
curl_setopt($ch, CURLOPT_URL, $rpcurl);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_TIMEOUT, 1);
$results = curl_exec($ch);
curl_close($ch);
return $results;
?>