AST

MDX, the library, uses not one but two syntax trees. The first, MDXAST, represents markdown with embedded JSX, and is a superset of mdast. The second, MDXHAST, represent HTML with embedded JSX, and is a superset of hast.

MDX includes a specification to define the syntax and transpilation. It’s based on the remark/rehype/unified ecosystems to ensure robust parsing and the ability to leverage plugins from within your MDX. This can be leveraged by code formatters, linters, and implementations in other languages created by the community.

MDXAST

The majority of the MDXAST specification is defined by mdast. MDXAST is a superset with the following additional node types:

• jsx (instead of html)
• comment (instead of html comments)
• import
• export

Any MDX document without those constructs is valid mdast.

For more information, see the MDXAST specification.

MDXHAST

The majority of the MDXHAST specification is defined by hast. MDXHAST includes all nodes defined by MDXAST, except for Comment, as it’s defined by hast already.

MDXAST defines the following additional node types:

• jsx (instead of html)
• import
• export
• inlineCode

inlineCode is there to accurately represent Markdown’s inline code.

For more information, see the MDXHAST specification.