> ## Documentation Index
> Fetch the complete documentation index at: https://developers.octaviatech.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Create Subcategory

> How to create a multilingual subcategory in Octavia AI CMS.

Each **subcategory** in Octavia AI CMS belongs to exactly **one category**, identified by the `categoryId` field.\
Subcategories support multiple languages, following the same **standard multilingual format** used across the CMS.

Example:

```json theme={null}
"name": {
  "en": "Artificial Intelligence",
  "es": "Inteligencia Artificial",
  ...
}
```

***

## Rules

* ✅ Each subcategory must have a valid **`categoryId`** belonging to an existing category
* ✅ Multilingual fields (`name`, `description`) must use lowercase ISO 639-1 codes (`en`, `es`, etc.)
* ✅ At least one language entry is required
* ✅ Slug must be unique within the parent category
* ❌ A subcategory **cannot** belong to more than one category
* ❌ Do not send plain strings for multilingual fields

***

## Validation & Behavior

* **categoryId** is required and must reference a valid category
* **Slug** must be unique within that category
* **Name** and **description** are multilingual fields
* **Thumbnail** and **isPrivate** are optional
* **Language fallback** applies when fetching data (default language is returned if the requested locale is missing)