Purpose

XML-RPC endpoint for remote publishing and legacy APIs (MetaWeblog, Blogger, MovableType, etc.).

Flow

• Defines XMLRPC_REQUEST and clears cookies.
• Reads raw POST body and loads WordPress.
• If ?rsd is requested, outputs RSD discovery document and exits.
• Loads admin includes and XML-RPC server classes.
• Instantiates the XML-RPC server class (filterable) and serves the request.

Key functions called

• site_url() / bloginfo_rss()
• apply_filters( 'wp_xmlrpc_server_class', ... )
• $wp_xmlrpc_server->serve_request()

Hooks fired

• Actions:
  • xmlrpc_rsd_apis
• Filters:
  • wp_xmlrpc_server_class