How to get the API Endpoint URL
The API Endpoint URL is usually
https://[site]/xmlrpc.php, where [site] is the path to your site. If you want to confirm this in a browser, simply type the URL into the address bar and press return. A normal response from a WordPress blog will read:
XML-RPC server accepts POST requests only.
This is not a sign of an error, but reflects the fact that WordPress expects an app like MarsEdit to connect to the URL, instead of a browser.
If this doesn’t work, take a look inside your WordPress directory on the blog server, to see if your
xmlrpc.php file has been moved or renamed. Finally, it’s possilbe that your web hosting company is blocking access to the xmlrpc.php, so you should contact them to confirm access is available to apps such as MarsEdit.
How to get the Blog ID
The Blog ID for WordPress is always simply: 1