Thanks! And no not at all, just HTML, CSS, and JavaScript. Although yes, I have it on the roadmap to be able to plop in React/Vue/Svelte components instead.
I would love to migrate from headless Wordpress + Gatsby to this when you start supporting React. Wordpress has a new editor I was hopeful for, but it's a nightmare.
The developer experience and infrastructural decisions are insane. Things may have changed since last year, but WP would throw user-level exceptions if the layout from any react component changed, and the components are expected to output an array of deprecated and current output. Meaning if your React component changes one CSS class, the user sees an unrecoverable error, and your component needs to emit the previous and current markup to satisfy the renderer. There wasn't even a developer mode to disable this. Then the component-level user input is stored as an HTML comment inside the markup. So many other problems, plus all of the existing WP issues with plugin security and a bloated, inelegant managed service.
One of my teams implemented everything thinking these were rough edges that would eventually be ironed out, but realized too late that WP is making terrible decisions and is stuck in a 2005~ mindset. Github issues are filled with the poor souls tasked with enterprise implementations meeting Automattic's (presumably overwhelmed) indifference.
It's frustrating because to my knowledge there aren't any enterprise grade WYSIWYG CMSes that let you freeform edit/rearrange React in-place – this is or was the closest as far as UX is concerned.
