Custom Theme

A theme in Nextra works like a layout, that will be rendered as a wrapper for all pages. This docs will walk you through the process of creating a custom theme.

Optionally, you can deploy an example and build further on it by following the below steps:

(opens in a new tab)

Create a Custom Theme

Configure Nextra to Use the Theme

First, you need to tell Nextra to use your custom theme file instead of official ones. In your Next.js config, you can pass the path to your theme file to the Nextra plugin:

next.config.js

const withNextra = require('nextra')({
  theme: './theme.tsx',
})
 
module.exports = withNextra({
  // Other Next.js configurations
  ...
})

Create a Basic Theme

You can now start working on your theme! In your root directory, create the corresponding theme.tsx file with basic content:

theme.tsx

import type { NextraThemeLayoutProps } from 'nextra'
 
export default function Layout({ children }: NextraThemeLayoutProps) {
  return (
    <div>
      <h1>My Theme</h1>
      <div style={{ border: '1px solid' }}>{children}</div>
    </div>
  )
}

It accepts a children prop, which is the MDX content of the current page, and wraps some other elements around the content. After creating the theme, you can simply add a MDX file as pages/index.mdx and see the result:

Inside your theme layout, you can use CSS imports or other ways to style it. Next.js hooks such as useRouter, Head are also available.

Render Metadata for the Active Page

Other than children, some other useful props are passed to the theme layout too. With the pageOpts props, the theme can access the page’s meta information.

For example, let’s implement these features:

Render the page title in <title>
Show a simple table of contents
Add a meta tag for og:image via the front matter

theme.tsx

import Head from 'next/head'
import type { NextraThemeLayoutProps } from 'nextra'
 
export default function Layout({ children, pageOpts }: NextraThemeLayoutProps) {
  const { title, frontMatter, headings } = pageOpts
 
  return (
    <div>
      <Head>
        <title>{title}</title>
        <meta name="og:image" content={frontMatter.image} />
      </Head>
      <h1>My Theme</h1>
      Table of Contents:
      <ul>
        {headings.map(heading => (
          <li key={heading.value}>{heading.value}</li>
        ))}
      </ul>
      <div style={{ border: '1px solid' }}>{children}</div>
    </div>
  )
}

Use Page Map of the Entire Site

Now, if you want to render something like a sidebar or a navigation bar, which relies on information of not only the current page but also other pages, you can use the pageMap value.

For example, we can render a simple navigation list with all the pages in the top level:

theme.tsx

import Link from 'next/link'
import type { NextraThemeLayoutProps } from 'nextra'
 
export default function Layout({ children, pageOpts }: NextraThemeLayoutProps) {
  const { pageMap } = pageOpts
 
  return (
    <div>
      <h1>My Theme</h1>
      {pageMap.map(item => {
        if (item.kind === 'MdxPage') {
          return (
            <Link key={item.name} href={item.route}>
              {item.route}
            </Link>
          )
        }
        return null
      })}
      <div style={{ border: '1px solid' }}>{children}</div>
    </div>
  )
}

There are other item kinds such as Folder (for directories) and Meta (for _meta.json files). All the items are typed so you can easily know the properties.

Advanced Usage

⚠️

Docs for advanced usage are under construction.

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