The collection of schemas used in WordPress, including the theme.json and block.json schemas.

JSON schemas are used by code editors to offer tooltips, autocomplete, and validation.

Many editors recognize the $schema property in JSON files.

Update your block.json to include:

{
	"$schema": "https://schemas.wp.org/trunk/block.json"
}

Or in your theme.json:

{
	"$schema": "https://schemas.wp.org/trunk/theme.json"
}

For a specific version of the schema, replace trunk with wp/X.X:

{
	"$schema": "https://schemas.wp.org/wp/5.8/block.json"
}

Visual Studio Code and PhpStorm are two popular editors that work out of the box. However, some editors require a plugin installed, and not all editors recognize the $schema property. Check your editor's documentation for details. Additionally, SchemaStore.org and JSON Schema have lists of editors known to have support if your current editor is unsupported.