How to serve index.mdx in a directory the same as a mdx with the same name as the directory

[maurxce]

Hey, sorry if this has been answered already / if this is worded badly.
I'm still on Nextra 3 and have been trying to figure out how to achieve this:

pages
|- my-directory
  |- index.mdx
  |- [...]

to act the same as

pages
|- my-directory.mdx

This is how it's being displayed right now

Edit:

• Using pages router and tried asIndexPage
• MIgrating to Nextra 4 is currently not an option, as I'm using remark plugins (see loader warning: https://the-guild.dev/blog/nextra-4#turbopack-support / v3 to v4 Migration: custom mdxOptions (remarkPlugins) support? #5038)

[MILLERMARRU]

asIndexPage won't help here, and I checked why: I pulled the actual nextra@3.3.1 package and looked at dist/client/normalize-pages.js. The merge logic that collapses a folder into a single sidebar link only triggers when a sibling file and folder share the same name at the same directory level:

const prevItem = list[index - 1];
if (prevItem && prevItem.name === item.name) {
  items[items.length - 1] = { ...prevItem, withIndexPage: true, frontMatter: item.frontMatter };
  continue;
}

That's comparing two entries in the same parent's file list, e.g. pages/fruits.mdx next to pages/fruits/ (with other pages inside). It's never comparing a folder's name against its own nested index.mdx, because those live at different tree levels; the folder is one item in the parent list, and index.mdx is a child of that folder, not a sibling of it. I also checked dist/server/page-map.js, and confirmed what the page-map builder actually produces for your structure: a folder entry named my-directory whose children array contains an entry named index, both resolving to route /my-directory. The theme renders that literally: an expandable folder containing one child page called "index", which is exactly your screenshot.

asIndexPage as front matter is a real option, but it only exists in the App Router / page.mdx codepath (packages/nextra/src/server/page-map/normalize.ts), which didn't exist yet in v3's pages router source I pulled, that's why setting it silently did nothing for you.

For pages router in v3, the supported way to collapse a folder into one link is the sibling pattern from the docs, not a nested index:

pages/
  my-directory.mdx       <- the folder's own content lives here
  my-directory/
    sub-page.mdx          <- only if you actually have nested pages

If my-directory only ever has the one page and nothing nested under it, simplest fix is to drop the folder entirely and just have pages/my-directory.mdx. If you do need sub-pages later, keep both my-directory.mdx and the my-directory/ folder side by side and Nextra will do the merge (withIndexPage: true) automatically, same as the "fruits" example in the docs.