Content

June 21, 2026 · View on GitHub

The site uses Astro's Content Collections to manage documentation and resources. The configuration is defined in src/content.config.ts.

Collections

CollectionLocationDescription
docssrc/content/docs/Versioned documentation pages (guides)
apisrc/content/api/Versioned API reference documentation
pagessrc/content/pages/Global pages: non-versioned docs, resources, support, and more
blogsrc/content/blog/Blog posts

Note

For a guide on writing and publishing blog posts, see How to write a blog post.

Frontmatter Schema

Each content file requires frontmatter with the following properties:

---
title: 'Page Title' # Required: The page title
description: 'Description' # Optional: Page description for SEO
---

Using Components in Content (MDX)

Content files that need to use interactive components must use the .mdx extension instead of .md. MDX allows you to import and use Astro components directly inside your markdown content.

Available Components

ComponentImportDescription
Alertimport Alert from '@components/primitives/Alert/Alert.astro'Contextual alerts with info, warning, and alert types

Example

---
title: My page title
description: A page with alerts
---

import Alert from '@components/primitives/Alert/Alert.astro';

Regular markdown content here.

<Alert type="info">This is an informational note.</Alert>

<Alert type="warning">This is a warning message.</Alert>

<Alert type="alert">This is a critical alert.</Alert>

Component imports must be placed after the frontmatter block and before the content where they are used. Do not place imports inside the frontmatter (---) block.

Code Tabs

Show the same snippet as CommonJS / ESM / TypeScript variants behind a tab strip. Tag each fenced code block with a dialect language and the tabs are built for you — consecutive tagged blocks are grouped into a single CodeTabs, and its import is injected automatically (no manual import needed).

FenceTab labelHighlighted as
cjsCommonJSJavaScript
mjsESMJavaScript
tsTypeScriptTypeScript
```cjs
const express = require('express');
const app = express();
```

```mjs
import express from 'express';
const app = express();
```

```ts
import express, { Express } from 'express';
const app: Express = express();
```

For labels other than these dialects, tag the blocks with tab="..." instead:

```js tab="npm"
npm install express
```

```js tab="pnpm"
pnpm add express
```

API Reference

The API reference lives in its own collection at src/content/api/, organized by version. Unlike docs, the API collection is not language-scoped — it is only available in English.

Structure

src/content/api/
├── 3x/
│   ├── api.mdx                    # API overview
│   └── api/
│       ├── application/           # express() and app methods
│       ├── middleware/             # Built-in middleware
│       ├── request/               # req object
│       └── response/              # res object
├── 4x/
│   ├── api.mdx
│   └── api/
│       ├── application/
│       ├── express/               # express module-level methods
│       ├── middleware/
│       ├── request/
│       ├── response/
│       └── router/                # Router (added in 4.x)
└── 5x/
    ├── api.mdx
    └── api/
        ├── application/
        ├── middleware/
        ├── request/
        ├── response/
        └── router/

URL Patterns

  • Versioned: /en/5x/api/application → Express 5.x application API
  • Non-versioned: /en/api/application → Defaults to Express 5.x

Versioning

The Express.js documentation supports multiple versions. Content is organized by version in both the docs and api collections.

Version Structure

src/content/docs/
└── en/
    ├── 3x/          # Express 3.x documentation
    ├── 4x/          # Express 4.x documentation
    └── 5x/          # Express 5.x documentation (default)

How Versioning Works

The version list, prefixes, and default version are defined once in src/config/versions.ts (VERSIONS, VERSION_PREFIXES, DEFAULT_VERSION) and consumed everywhere else.

  • Default Version: 5x is the current default version (isDefault: true in VERSIONS)
  • Supported Versions: 5x, 4x, 3x
  • URL Patterns:
    • Versioned: /en/5x/api/ → Express 5.x API docs
    • Non-versioned: /en/api/ → Defaults to Express 5.x

Adding Version Specific Content

  1. Create your content file in the appropriate version directory:

    src/content/docs/en/5x/guide/my-new-page.md

  2. The versioning system (configured in src/pages/[lang]/[...slug].astro) will automatically:

    • Serve the page at /en/5x/guide/my-new-page
    • Create non-versioned aliases for default version content

Adding a New Version

To add support for a new Express version (e.g., 6x):

  1. Create content directories:

    • src/content/docs/en/6x/ — Guides and documentation
    • src/content/api/6x/ — API reference

  2. Update the version type in src/config/types.ts:

    export type VersionPrefix = '6x' | '5x' | '4x' | '3x';

  3. Add the version to src/config/versions.ts — the single source of truth for the version list, prefixes, and default version:

    export const VERSIONS: VersionOption[] = [
  { id: '6x', label: 'v6.x', isDefault: true },
  { id: '5x', label: 'v5.x' },
  { id: '4x', label: 'v4.x' },
  { id: '3x', label: 'v3.x (deprecated)', isDeprecated: true },
];

    DEFAULT_VERSION and VERSION_PREFIXES are derived from this array, and the routing (src/pages/[lang]/[...slug].astro), the sidebar, and the link-localization plugins all read from it — so you don't update the version in those places anymore.

  4. Update menu versioning in src/config/menu/main.ts:

    • Add '6x' to the versioned arrays

  5. Review omitFrom entries in src/config/menu/api.ts:

    • Determine which API features exist or are deprecated in the new version

Global Pages (Non-Versioned)

Some documentation pages are shared across all versions and don't belong to a specific Express version (e.g., security updates, migration guides, performance best practices). These pages live in the pages collection instead of docs.

Structure

src/content/pages/
└── en/
    ├── advanced/
    │   ├── best-practice-performance.md
    │   ├── best-practice-security.mdx
    │   ├── healthcheck-graceful-shutdown.md
    │   └── security-updates.mdx
    ├── guide/
    │   ├── database-integration.mdx
    │   ├── migrating-4.mdx
    │   └── migrating-5.mdx
    ├── resources/
    │   ├── community.md
    │   ├── contributing.md
    │   ├── glossary.mdx
    │   ├── utils.md
    └── support.md

Pages with a slug starting with resources/ are treated as resource pages and won't show "Docs" in the breadcrumbs.

Adding a Global Page

  1. Create your content file in src/content/pages/:

    src/content/pages/en/guide/my-global-page.md

  2. Add the menu item in src/config/menu/docs.ts with global: true:

    {
  href: `/guide/my-global-page`,
  label: 'menu.myGlobalPage',
  ariaLabel: 'menu.myGlobalPageAria',
  global: true,
}

    The global: true flag tells the sidebar to generate the link without a version prefix and prevents the version switcher from modifying its URL.

Write internal links without a language prefix (and usually without a version) — just the section path. Two plugins localize them at build time so every page links within its own language and version:

  • src/plugins/remark-rewrite-localized-links.mjs — Markdown links [text](/...).
  • src/plugins/rehype-rewrite-localized-links.mjs — raw HTML/JSX anchors <a href="/..."> (e.g. cards that wrap a <Card> component), which Markdown link syntax can't express.

Both share the logic — and the defaults — in src/plugins/rewrite-localized-links-core.mjs (DEFAULT_PREFIXES = localizable sections, DEFAULT_VERSIONED_SECTIONS = sections that carry a version; the latest version comes from src/config/versions.ts and the unversioned "global" pages are derived from the menu). They're registered in astro.config.mjs with no options needed.

For a link authored in a Spanish, 5.x page:

Write thisRenders asWhy
/api/express/es/5x/api/express/versioned section → file version injected
/guide/routing/es/5x/guide/routing/versioned docs page → file version injected
/guide/migrating-5/es/guide/migrating-5/"global" page → no versioned URL, stays bare
/4x/api/express/es/4x/api/express/explicit version is preserved
/resources/middleware/es/resources/middleware/resources is never versioned

Rules:

  • Always omit the language. The plugin prepends the current page's language. Never write /en/... — translations sync from Crowdin verbatim, so a hardcoded language would make translated pages link back to English.
  • Versioned sections (api, starter, guide, advanced) carry a version: the link's own version is kept, or the source file's version (in docs/api) — or the latest (DEFAULT_VERSION) from a non-versioned collection — is injected when the link omits one. Write /api/express or /guide/routing; in a 5.x file both resolve under /…/5x/….
  • "Global" pages are the exception. A handful of guide/advanced pages live in the unversioned pages collection (migrating-5, best-practice-performance, …) and have no versioned URL, so links to them always stay unversioned. This list is derived from the menu items flagged global: true (in src/config/menu/) — no manual upkeep. (Adding a global page already requires that flag; see Adding a Global Page.)
  • resources, support, blog are never versioned; links are language-only.
  • External URLs, relative links (./x), pure anchors (#x) and already-localized links (/en/...) are left untouched.