WordPress gems for devs: Interactivity API

Repository for code examples and resources used in the "WordPress gems for devs: Interactivity API" talk.

Event	Date	Branch	Links
IPC Munich 2025	30 October 2025	conf/IPC-Munich-2025	Event | Slides
IPC Berlin 2025	4 June 2025	conf/IPC-Berlin-2025	Event | Slides
WordCamp Lisboa 2025	17 May 2025	conf/WordCamp-Lisboa-2025	Event | Slides | Video

What problems does it solve?

• Compatibility with PHP hooks.
• Inter-block communication.
• Site-wide features such as client-side navigation.

Reference

• Interactivity API Reference
  • The Reactive and Declarative mindset
    • List of Directives
  • Understanding global state, local context and derived state
    • The store
  • Server-side rendering: Processing directives on the server
    • Server functions
• WP_Interactivity_API_Directives_Processor
• @wordpress/create-block-interactive-template

Examples

• The movie demo, GitHub repo
• Countdown
• Instant Search
• Todo list
• Interactivity API showcase

Examples in production:

• mainostoimistot.fi - Query Loop Filters by Sami Keijonen, forked from humanmade/query-filter
• Podcaster Plus plugin by Dan Maby and Nathan Wrigley

Resources

• Interactivity API: Roadmap
• Proposal: The Interactivity API – A better developer experience in building interactive blocks
• Interactivity API discussions
• Changelog - Tracking Breaking Changes in the Interactivity API
• Getting Started - and other learning resources

History

The idea of using the declarative method to bridge the connection between frontend and backend came from the Cloudfest 2022 Hackathon project, Bento + WordPress, which was led by Alain Schlesser and Pascal Birchler.

Equivalents in other PHP frameworks

• Laravel - Livewire using AlpineJS
• Symfony UX - Live components, primarily built on top of Turbo and Stimulus, which are part of the Hotwire framework.
• Phoenix LiveView