---
name: docusaurus-advanced
description: Deep dive into the Docusaurus configuration, plugins, and custom fields.
---
# Docusaurus Configuration
## Config File
- **File**: `textbook/docusaurus.config.ts`
- **Type**: TypeScript config.
## Integrations
- **API URL**: Exposed to client via `customFields`.
```ts
customFields: {
apiUrl: process.env.DOCUSAURUS_API_URL || 'http://127.0.0.1:8000',
}
```
- **AuthBar**: A custom navbar item registered in `textbook/src/theme/NavbarItem` (if swizzled) or imported specifically.
## Plugins & Presets
- **Preset**: `classic` (standard docs, blog, pages).
- **Sidebar**: Defined in `textbook/sidebars.ts`.
## Theme Swizzling
- **Custom CSS**: `textbook/src/css/custom.css` (contains specific overrides for dark mode and premium UI).
- **Layout**: `Layout` wrapper is often used in `src/pages` for standalone React pages within Docusaurus.
## MDX
We support MDX for interactive components within documentation.