How to make a post to wordpress using the api?
yeah you can use metaWeblog.newPost or blogger.newPost, an example of the first:
http://www.wprecipes.com/post-on-your-wordpress-blog-using-php
uses curl and xmlrpc_encode_request
an example of the second:
http://www.nickycakes.com/post-to-wordpress-remotely-with-xmlrpc-in-php/
yeah and @Francis is correct