While you should use the site editor interface as much as possible, you’ll still need to manually edit theme.json for certain features. Here’s what you need to know about this crucial file.
The only absolute requirement is a version key (currently version 3 as of WordPress 6.6). Adding a schema reference helps your code editor provide autocomplete and error checking – super helpful when working with such a large file.
The two main sections you’ll work with are “settings” (creating your design system) and “styles” (though most styling should be done through the interface). Additional sections handle pattern registration, custom templates, and template part areas.
While theme.json can get quite large, using a good code editor with schema support makes manual editing much more manageable. Just remember – use the visual interface whenever possible and only fall back to manual editing when necessary.