In WordPress 5.5, a handful of entirely new REST API endpoints have been introduced and several others will see new features or enhancements. Let’s look at a breakdown of these changes.
In  REST API endpoints were introduced to return all of the block types registered on the server.
GET /wp/v2/block-types will return all registered block types. GET /wp/v2/block-types/core will return all blocks within the core namespace. GET /wp/v2/block-types/core/quote will return the definition specifically for the core quote block.
This endpoint is accessible to users that have edit permission for any post type that is