W-Shadow.com

[Here’s some list-cliche-filler stuff while I fight off a (hopefully) temporary bout of unproductivity and dentists]

WordPress internals are documented pretty well, but sometimes finding the right API/Codex page can take a while. That’s why I’ve decided to put together a comprehensive list of all APIs used by WordPress to serve as a “jump-off point” for plugin developers and WP hackers. Let me know if I’ve missed any APIs and I’ll add them to the list.

Plugin/Core API Reference

• Action reference
• Filter reference
• Function reference
• Template tags
• Shortcode API
• Sidebar Widgets API
• Advanced Topics category at Codex

Database API

• wpdb class – the WP database abstraction layer
• Database description & table overview
• WordPress database schema (outdated)
• MySQL 5.0 reference manual

Feeds

• Feed Action reference
• RSS 2.0 specification
• Magpie RSS / How-To’s – the RSS/Atom parser used by WordPress
• Atom (a Wikipedia page)
• Atom Publishing Protocol and WordPress

XML-RPC – Remote Control For WordPress

• XML-RPC homepage
• IXR (Incution XML-RPC Library) – the XML-RPC library used by WordPress
• Blogger API
• metaWeblog API
• Movable Type API

Trackbacks & Pingbacks

• Pingback specification
• Trackback specification
• See also the trackback() and pingback() functions in wp-includes/comment.php.

TinyMCE Rich Text Editor

• TinyMCE Codex page
• Relevant hooks
• Official TinyMCE docs

External APIs

• Akismet API Documentation
• Plugin Information API (api.wordpress.org) – an informal writeup