WordPress Block Development: September’s Core Updates Deliver

Just last week, a client hit me up. Their marketing team was wrestling with an existing page, trying to add some simple accordions and custom-styled form fields without breaking anything. The current setup? A total nightmare of custom JS and inline styles from an older theme. I looked at it and thought, “Man, this used to be a headache to implement properly, especially if you needed it accessible.” But here’s the kicker: WordPress core, especially with the September 2025 updates, is making this kind of stuff genuinely straightforward now.

If you’ve been knee-deep in custom block development, or just trying to keep up with how WordPress is evolving, these updates are solid. They’re not flashy marketing buzz; they’re practical tools that make our jobs easier and client sites more robust. We’re talking about significant strides in core functionality that streamline development, reduce custom code, and ultimately, make sites more maintainable.

Streamlining WordPress Block Development

First up, the official “What’s new for developers?” September 2025 report on the WordPress Developer Blog highlights the new **Accordion block**. This has been a long time coming. We’ve all built countless custom accordion solutions, often fighting with accessibility standards (WCAG, USWDS) or patching things together with conflicting JavaScript. Now, WordPress gives us native Accordion, Accordion Item, Header, and Panel blocks, all powered by the Interactivity API. This means less custom code, better semantics out of the box, and a more consistent user experience. Trust me, rolling your own accessible accordion from scratch is not fun, and having this in core is a huge win for cleaner block development.

Next, let’s talk about styling. Remember the days of fighting with global CSS overrides for basic form elements? It was messy. With the continued effort to allow `theme.json` to style form elements, you can now target text inputs, textareas, and even select/dropdown elements directly. This is massive for maintaining a consistent design system. You can centralize your form styling right in your theme’s `theme.json`, making it predictable and easy to manage without adding a bunch of extra CSS that conflicts everywhere. For example, to style your text inputs:

"elements": {
	"textInput": {
		"border": {
			"radius": "0",
			"style": "solid",
			"width": "1px",
			"color": "red"
		},
		"color": {
			"text": "var(--wp--preset--color--theme-2)"
		},
		"typography": {
			"fontFamily": "var(--wp--preset--font-family--inter)"
		}
	}
}

This kind of control, right from `theme.json`, removes a ton of boilerplate and ensures your styles are applied universally. It’s what we always wanted for true block themes, and it’s finally here.

Beyond styling, the `@wordpress/create-block` package now allows block variants to define their own template files. If you’ve ever built complex blocks with many variations, you know the pain of conditional logic within a single template. This update simplifies managing those templates significantly. It’s a small change, but it makes a huge difference in the long-term maintainability of your custom blocks.

And speaking of foundational work, the **Abilities API** is getting a Composer package and the PHP AI Client saw its first stable release. For those integrating advanced permissions or dabbling with AI in WordPress, this is the groundwork being laid. It means a more structured and official way to extend core functionality, rather than relying on custom solutions that might break with every major update.

So, What’s the Point?

The takeaway here is clear: WordPress core development is moving fast, and in the right direction. These aren’t just minor tweaks; they are foundational improvements that empower developers to build better, more maintainable, and more compliant sites with less effort. Leveraging these core features means fewer custom hacks, less technical debt, and more time focusing on what really matters for your clients.

Look, this stuff gets complicated fast. If you’re tired of debugging someone else’s mess and just want your site to work, drop my team a line. We’ve probably seen it before.