@astrojs/ mdx

This Astro integration enables the usage of MDX components and allows you to create pages as .mdx files.

Why MDX?

MDX allows you to use variables, JSX expressions and components within Markdown content in Astro. If you have existing content authored in MDX, this integration allows you to bring those files to your Astro project.

Installation

Astro includes an astro add command to automate the setup of official integrations. If you prefer, you can install integrations manually instead.

Run one of the following commands in a new terminal window.

npx astro add mdx

pnpm astro add mdx

yarn astro add mdx

If you run into any issues, feel free to report them to us on GitHub and try the manual installation steps below.

Manual Install

First, install the @astrojs/mdx package:

npm install @astrojs/mdx

pnpm add @astrojs/mdx

yarn add @astrojs/mdx

Then, apply the integration to your astro.config.* file using the integrations property:

import { defineConfig } from 'astro/config';
import mdx from '@astrojs/mdx';

export default defineConfig({
  // ...
  integrations: [mdx()],
});

Editor Integration

For editor support in VS Code, install the official MDX extension.

For other editors, use the MDX language server.

Usage

With the Astro MDX integration, you can add MDX pages to your project by adding .mdx files within your src/pages/ directory. You can also import .mdx files into .astro files.

Astro’s MDX integration adds extra features to standard MDX, including Markdown-style frontmatter. This allows you to use most of Astro’s built-in Markdown features like a special frontmatter layout property.

See how MDX works in Astro with examples in our Markdown & MDX guide.

Visit the MDX docs to learn about using standard MDX features.

Configuration

Once the MDX integration is installed, no configuration is necessary to use .mdx files in your Astro project.

You can configure how your MDX is rendered with the following options:

Options inherited from Markdown config
extendMarkdownConfig
recmaPlugins
optimize

Options inherited from Markdown config

All markdown configuration options can be configured separately in the MDX integration. This includes remark and rehype plugins, syntax highlighting, and more. Options will default to those in your Markdown config (see the extendMarkdownConfig option to modify this).

import { defineConfig } from 'astro/config';
import mdx from '@astrojs/mdx';
import remarkToc from 'remark-toc';
import rehypeMinifyHtml from 'rehype-minify-html';

export default defineConfig({
  // ...
  integrations: [
    mdx({
      syntaxHighlight: 'shiki',
      shikiConfig: { theme: 'dracula' },
      remarkPlugins: [remarkToc],
      rehypePlugins: [rehypeMinifyHtml],
      remarkRehype: { footnoteLabel: 'Footnotes' },
      gfm: false,
    }),
  ],
});

See the Markdown Options reference for a complete list of options.

`extendMarkdownConfig`

Type: boolean
Default: true

MDX will extend your project’s existing Markdown configuration by default. To override individual options, you can specify their equivalent in your MDX configuration.

For example, say you need to disable GitHub-Flavored Markdown and apply a different set of remark plugins for MDX files. You can apply these options like so, with extendMarkdownConfig enabled by default:

import { defineConfig } from 'astro/config';
import mdx from '@astrojs/mdx';

export default defineConfig({
  // ...
  markdown: {
    syntaxHighlight: 'prism',
    remarkPlugins: [remarkPlugin1],
    gfm: true,
  },
  integrations: [
    mdx({
      // `syntaxHighlight` inherited from Markdown

      // Markdown `remarkPlugins` ignored,
      // only `remarkPlugin2` applied.
      remarkPlugins: [remarkPlugin2],
      // `gfm` overridden to `false`
      gfm: false,
    }),
  ],
});

You may also need to disable markdown config extension in MDX. For this, set extendMarkdownConfig to false:

import { defineConfig } from 'astro/config';
import mdx from '@astrojs/mdx';

export default defineConfig({
  // ...
  markdown: {
    remarkPlugins: [remarkPlugin1],
  },
  integrations: [
    mdx({
      // Markdown config now ignored
      extendMarkdownConfig: false,
      // No `remarkPlugins` applied
    }),
  ],
});

`recmaPlugins`

These are plugins that modify the output estree directly. This is useful for modifying or injecting JavaScript variables in your MDX files.

We suggest using AST Explorer to play with estree outputs, and trying estree-util-visit for searching across JavaScript nodes.

`optimize`

Type: boolean | { ignoreElementNames?: string[] }

This is an optional configuration setting to optimize the MDX output for faster builds and rendering via an internal rehype plugin. This may be useful if you have many MDX files and notice slow builds. However, this option may generate some unescaped HTML, so make sure your site’s interactive parts still work correctly after enabling it.

This is disabled by default. To enable MDX optimization, add the following to your MDX integration configuration:

import { defineConfig } from 'astro/config';
import mdx from '@astrojs/mdx';

export default defineConfig({
  // ...
  integrations: [
    mdx({
      optimize: true,
    }),
  ],
});

`ignoreElementNames`

Type: string[]

Added in: @astrojs/mdx@3.0.0 Beta

Previously known as customComponentNames.

An optional property of optimize to prevent the MDX optimizer from handling certain element names, like custom components passed to imported MDX content via the components prop.

You will need to exclude these components from optimization as the optimizer eagerly converts content into a static string, which will break custom components that needs to be dynamically rendered.

For example, the intended MDX output of the following is <Heading>...</Heading> in place of every "<h1>...</h1>":

---
import { Content, components } from '../content.mdx';
import Heading from '../Heading.astro';
---

<Content components={{ ...components, h1: Heading }} />

To configure optimization for this using the ignoreElementNames property, specify an array of HTML element names that should be treated as custom components:

import { defineConfig } from 'astro/config';
import mdx from '@astrojs/mdx';

export default defineConfig({
  // ...
  integrations: [
    mdx({
      optimize: {
        // Prevent the optimizer from handling `h1` elements
        ignoreElementNames: ['h1'],
      },
    }),
  ],
});

Note that if your MDX file configures custom components using export const components = { ... }, then you do not need to manually configure this option. The optimizer will automatically detect them.