WordPress/wp-includes/blocks/embed/block.json

{
	"apiVersion": 2,
	"name": "core/embed",
	"title": "Embed",
	"category": "embed",
	"description": "Add a block that displays content pulled from other sites, like Twitter, Instagram or YouTube.",
	"textdomain": "default",
	"attributes": {
		"url": {
			"type": "string"
		},
		"caption": {
			"type": "string",
			"source": "html",
			"selector": "figcaption"
		},
		"type": {
			"type": "string"
		},
		"providerNameSlug": {
			"type": "string"
		},
		"allowResponsive": {
			"type": "boolean",
			"default": true
		},
		"responsive": {
			"type": "boolean",
			"default": false
		},
		"previewable": {
			"type": "boolean",
			"default": true
		}
	},
	"supports": {
		"align": true
	},
	"editorStyle": "wp-block-embed-editor",
	"style": "wp-block-embed"
}