# About the Wix Categories API

> **Note:**
> Currently, only the [Wix Stores Catalog V3 API](fallback::https://dev.wix.com/docs/rest/business-solutions/stores/catalog-v3/introduction) supports the Categories API.

The Wix Categories API allows you to create and manage a tree of categories on your site. 

This API provides essentials tools to establish hierarchical relationships between categories, helping you organize and classify items assigned to these categories.

With the Wix Categories API, you can:
- Manage categories and assign them to parent categories.
- Add and remove items from categories.
- Specify the manual arrangement of items within a category.
- Retrieve information about items assigned to a category, directly or indirectly.

## Before you begin
It’s important to note the following points before starting to code:
- The Categories app is currently only available as part of the Wix stores app. Make sure to install the Wix Stores app from the [Wix App Market](fallback::https://www.wix.com/app-market/wix-stores).
- Your app has the necessary permissions to access the Categories API.

## Limitations
Wix Categories is currently limited to:
1. 1,000 Categories per Tree.
2. Up to 5 hierarchies levels. 
3. Each category can belong to only one parent category. 
4. Items can be associated with many categories, up to 1,000. 
5. Only the first 100 items within a category can be arranged manually. 
6. Updating visible field to `false` and delete behaviors apply from parent categories to subcategories.

## Sample flows
* [Create category and subcategory](fallback::https://dev.wix.com/docs/rest/business-management/categories/sample-use-cases-and-flows#create-category-and-subcategory)
* [Add and arrange items in category](fallback::https://dev.wix.com/docs/rest/business-management/categories/sample-use-cases-and-flows#add-and-arrange-items-in-category)
* [Move subcategory to a different position within a parent category](fallback::https://dev.wix.com/docs/rest/business-management/categories/sample-use-cases-and-flows#move-subcategory-to-a-different-position-within-a-parent-category)
* [Find all subcategories of a category](fallback::https://dev.wix.com/docs/rest/business-management/categories/sample-use-cases-and-flows#find-all-subcategories-of-a-category)

## Terminology
1. **Tree**: A hierarchical structure of categories. Each tree can have up to 1,000 categories.
2. **Tree Reference**: A unique identifier for the tree. Defined by app namespace and optionally tree key. Must be provided in all API requests.
3. **App Namespace**: A unique identifier for the app that owns the tree. This namespace must be defined in dev-center before using the API.
4. **Tree Key**: An optional key to differentiate between multiple trees managed by the same app. It can be empty, if an app only manages one tree. 
5. **Parent Category**: Each category can have a single parent category for managing a nested hierarchy. The parent Category can be empty when category is at the top level of the hierarchy or for flat category structures.
6. **SubCategory**: A category nested under another category. Multiple subcategories can exist under a single parent category.
7. **Depth**: The maximum nesting level allowed within the tree, limited to 5 levels.
8. **Breadcrumbs**: A path from top-level category to the current category, helping users understand their location within the hierarchy and navigate back to parent categories.
9. **Item Reference**: Identifies an item assigned to a category, consisting of an appId and a catalogItemId.
10. **Manual Arrangement**: Allows merchants to manually set the order of items within a category. Up to 100 items can be rearranged to make them displayed in the beginning, while the rest are displayed in the order they were added to the category.

# Categories: Sample Use Cases and Flows

This article shares some possible use cases your app could support, as well as
a sample flow that could support each use case. This can be a helpful jumping
off point as you plan your app's implementation.

## Create category and subcategory
Help merchant organize their hierarchy by creating new categories and subcategories.
1. To create new category call [Create Category](fallback::https://dev.wix.com/docs/rest/business-management/categories/create-category) endpoint. 
In the request body in addition to `category` you need to pass `treeReference` to specify the tree in which the category will be created.
The category will be created in the top nesting level of the tree.
```json
{
  "category": {
    "name": "Drinkware",
    "description": "The Drinkware category includes a wide range of containers designed for holding beverages",
    "visible": true
  },
  "treeReference": {
    "appNamespace": "@wix/stores",
    "treeKey": null
  }
}
```
Save `category.id` from response.

2. To create subcategory within the newly created category call [Create Category](fallback::https://dev.wix.com/docs/rest/business-management/categories/create-category) endpoint again.
This time, include the `parentCategory.id` to specify the parent category that will be assigned.
The `treeReference` will be the same as you sent in step 1.
```json
{
  "category": {
    "name": "Mugs",
    "description": "The Mugs subcategory includes a wide range of containers designed for holding hot beverages",
    "visible": true,
    "parentCategory": {
      "id": "<parentCategoryId>"
    }
  },
  "treeReference": {
    "appNamespace": "@wix/stores",
    "treeKey": null
  }
}
```
Replace `<parentCategoryId>` with category id from response of step 1.

## Add and arrange items in category
Help merchant to organize and classify their items by using categories.
In this scenario, you will assign set of items to a category and arrange them in a specific order.
1. Add selected items to category by calling [Bulk Add Items To Category](fallback::https://dev.wix.com/docs/rest/business-management/categories/bulk-add-items-to-category) endpoint.

In the request path, include `category.id` that you received in response of previous scenario. 
In the request body `treeReference` will also be the same and in `items` you can send all items that you want to add to category, Each item is referenced by pair of `appId` and `catalogItemId`.
```json
{
  "items": [
    {
      "catalogItemId": "0318a3d8-f31c-4ba3-98c7-387571a2eac4",
      "appId": "215238eb-22a5-4c36-9e7b-e7c08025e04e"
    },
    {
      "catalogItemId": "05519a6e-222b-413a-957c-0ef7a32779b5",
      "appId": "215238eb-22a5-4c36-9e7b-e7c08025e04e"
    },
    {
      "catalogItemId": "060b9b04-fe14-487d-8336-2d285c50cf98",
      "appId": "215238eb-22a5-4c36-9e7b-e7c08025e04e"
    }
  ],
  "treeReference": {
    "appNamespace": "@wix/stores",
    "treeKey": null
  }
}
```

3. After adding the items to the category, you can rearrange them for example to promote some items to be displayed in the beginning. Note that you can arrange up to 100 items, more items can be added, but you cannot control arrangement of them. 
Call [Set Arranged Items](fallback::https://dev.wix.com/docs/rest/business-management/categories/set-arranged-items) endpoint. Pass exactly same params as in step 1 but now `items` must be in desired order in which you want to see them.
4. To display all items that belong to given category in the specified arrangement from previous step, use [List Items In Category](fallback::https://dev.wix.com/docs/rest/business-management/categories/list-items-in-category) endpoint.
In the request path, include same `category.id` from previous steps and in the request body, send the following:
  
```json
{
  "useCategoryArrangement": true,
  "treeReference": {
    "appNamespace": "@wix/stores",
    "treeKey": null
  }
}
```

### Move subcategory to a different position within a parent category
Merchant may want to change the position of a category in the hierarchy.

1. Use the [Create Category](fallback::https://dev.wix.com/docs/rest/business-management/categories/create-category) endpoint to create an additional subcategory within the parent category.
   In the request body as part of the `category` you need to also provide `parentCategory.id` to specify the parent category that will be assigned.
```json
{
  "category": {
    "name": "Bottles",
    "description": "The Bottles subcategory offers a diverse selection of containers designed for carrying and consuming beverages",
    "visible": true,
    "parentCategory": {
      "id": "<parentCategoryId>"
    }
  },
  "treeReference": {
    "appNamespace": "@wix/stores",
    "treeKey": null
  }
}
```
Save `category.id` from response.

2. To move the category to a different position in same parent category call [Move Category](fallback::https://dev.wix.com/docs/rest/business-management/categories/move-category) endpoint. 
   In the request path, include the `category.id` of the category you want to move.
   In the request, provide the `parentCategoryId` and specify `position` as `FIRST` to move the subcategory to the beginning.
```json
{
  "parentCategoryId": "<parentCategoryId>",
  "position": "FIRST",
  "treeReference": {
    "appNamespace": "@wix/stores",
    "treeKey": null
  }
}
```
Replace `<parentCategoryId>` with category id from response of previous scenarios.

### Find all subcategories of a category

In this scenario, you want to retrieve a list of all subcategories that belong to a specific parent category, in the correct order. This is useful for traversing the category hierarchy.

Use the [Search Categories](fallback::https://dev.wix.com/docs/rest/business-management/categories/search-categories) endpoint.
In the request body, include the `parentCategory.id` in the `filter` parameter and sort by `parentCategory.index` in ascending order:
```json
{
    "search": {
      "filter": {"parentCategory.id": {"$eq": "<parentCategoryId>" }},
      "sort": [{"fieldName": "parentCategory.index", "order": "ASC"}]
    },
    "treeReference": {
      "appNamespace": "@wix/stores"
    },
    "fields": [
      "BREADCRUMBS_INFO"
    ]
}
```
Replace `<parentCategoryId>` with parent category id from previous scenarios.

# Categories: Supported Filters and Sorting

The following table shows field support for filters and sorting for the category object:

| Field                        | Supported Filters                                                       | Sortable |
|------------------------------|-------------------------------------------------------------------------|----------|
| `id`                         | `$eq`, `$ne`, `$exists`, `$in`, `$hasSome`, `$startsWith`               |          |
| `createdDate`                | `$eq`, `$ne`, `$exists`, `$in`, `$hasSome`, `$lt`, `$le`, `$gt`, `$ge`  | Sortable |
| `updatedDate`                | `$eq`, `$ne`, `$exists`, `$in`, `$hasSome`, `$lt`, `$le`, `$gt`, `$ge`  | Sortable |
| `name`                       | `$eq`, `$ne`, `$exists`, `$in`, `$hasSome`, `$startsWith`               | Sortable |
| `description`                | `$eq`, `$ne`, `$exists`, `$in`, `$hasSome`, `$startsWith`               |          |
| `visible`                    | `$eq`, `$ne`, `$exists`, `$in`, `$hasSome`                              |          |
| `slug`                       | `$eq`, `$ne`, `$exists`, `$in`, `$hasSome`, `$startsWith`               |          |
| `parentCategory.id`          | `$eq`, `$ne`, `$exists`, `$in`, `$hasSome`, `$startsWith`               | Sortable |
| `parentCategory.index`       | `$eq`, `$ne`, `$exists`, `$in`, `$hasSome`, `$lt`, `$le`, `$gt`, `$ge`  | Sortable |
| `treeReference.appNamespace` | `$eq`, `$ne`, `$exists`, `$in`, `$hasSome`, `$startsWith`               |          |
| `treeReference.treeKey`      | `$eq`, `$ne`, `$exists`, `$in`, `$hasSome`, `$startsWith`               |          |
| `treeReference.treeValue`    | `$eq`, `$ne`, `$exists`, `$in`, `$hasSome`, `$startsWith`               |          |


__Related content:__
[API Query Language](portalId::d1972c09-74e2-4d36-a6f2-54e3310d4ad9resourceId::8158a590-f60c-4606-9fed-16a34e275f3a*fallback::https://dev.wix.com/docs/rest/articles/getting-started/api-query-language),
[Search Categories](fallback::https://dev.wix.com/docs/rest/business-management/categories/search-categories)