September 2025 WordPress Developer Updates: New Blocks, AI Tools, and Theme.json Enhancements
WebCrimp analysis and practical explanation. AI-assisted; reviewed before publication.
Quick Summary
The September 2025 release brings a suite of developer‑focused features to WordPress, including an official Composer package for the upcoming Abilities API, an experimental Accordion block built with the Interactivity API, expanded theme.json capabilities for styling form elements and defining border‑radius presets, updates to Data Views and the Create Block tool, early AI integrations such as the PHP AI Client v0.1.0 and a Cursor‑compatible MCP adapter, and Playground improvements that let contributors earn badges and prototype PHP in the browser.
What Happened?
Key announcements include the availability of the wordpress/abilities-api Composer package for early testing, four new experimental blocks (Accordion, Accordion Item, Accordion Header, Accordion Panel) that rely on the Interactivity API, the ability to style text inputs, textareas and select dropdowns via theme.json elements, infinite scroll and new card layouts in Data Views, variant‑specific template files in @wordpress/create-block, the first stable release of the PHP AI Client and a demo AI chatbot, WordPress MCP adapter support for Cursor, Playground CLI flags for custom site URLs and auto‑mount folders, a browser‑based PHP Playground for prototyping, Date block enhancements with custom dates and block bindings, a new Query Loop Title variation for post type labels, early work on template duplication and active templates, and border‑radius preset definitions in theme.json.
Why It Matters
These updates lower the barrier to extend WordPress core with modern APIs, give designers tighter control over form appearance without custom CSS, improve developer ergonomics when building block variants, and introduce AI‑assisted capabilities that can be prototyped directly in the browser. Together they enable faster iteration, more accessible front‑end experiences, and a clearer path toward the upcoming WordPress 6.9 release.
Who Can Use It?
Software Development · Web Development · WordPress · AI/ML · DevOps · UI/UX · Graphic Design · Content
How Can I Use This?
If you work in Software Development, Web Development, WordPress, AI/ML, DevOps, UI/UX, Graphic Design, Content
- Software developers can start experimenting with the Abilities API by adding the wordpress/abilities-api package via Composer and building custom capability checks. Web developers can enable the Accordion block in Gutenberg Experiments to create accessible FAQs and then style its inner elements using theme.json. UI/UX designers can define border‑radius presets and form‑element styles in theme.json to maintain a consistent design system across blocks. DevOps engineers can use the updated Playground CLI with –site-url and –auto‑mount to spin up isolated testing environments for plugins and themes. AI/ML engineers can explore the PHP AI Client v0.1.0 and the Cursor‑compatible MCP adapter to integrate AI features into WordPress plugins, referencing the released chatbot demo as a starting point.
AI Tip
When prototyping AI features, use the browser‑based PHP Playground to test API calls locally before committing code to your repository.
AI Trick
Leverage the new useServerSideRender hook to fetch AI‑generated content on the server while keeping the client interface responsive, but remember to validate the output for security.
Example Workflow
- 1. Enable experimental blocks and the Form block in Gutenberg Experiments.
2. Add the Abilities API Composer package to your project.
3. Create a block variant that defines its own template file.
4. Style form inputs via theme.json elements.
5. Test AI interactions using the Playground CLI with –site-url set to a local URL.
*Verify each step with the latest documentation as features may still be experimental.
Copy This Prompt
You are a [PROFESSION] working on a WordPress site. Using the newly released [FEATURE] (e.g., Abilities API Composer package, Accordion block, theme.json form styling, PHP AI Client), describe a step‑by‑step approach to [GOAL] (e.g., add role‑based capabilities, build an accessible FAQ, style a contact form, prototype an AI chatbot). Include any required tools, verification steps, and a short code snippet placeholder.
Recommended Tools
- WordPress core
- Gutenberg plugin
- Composer
- PHP
- Playground CLI
- Node.js/npm
- Theme.json editor
Check official documentation, availability and pricing before using these suggestions.
Difficulty
Intermediate
Estimated Time Saved
Not measured; validate with your own workflow.
Source
WordPress Developer Blog – AI
What’s new for developers? (September 2025)
Original publication date: 2025-09-10T15:03:44+00:00