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

# List Categories

> Fetch Article categories. The response includes both top-level categories and subcategories; use `parent` to reconstruct the hierarchy, or filter with `parent_category` / `root_only`.

## Usage


## OpenAPI

````yaml get /v1/articles/categories
openapi: 3.0.1
info:
  title: Siit Public API
  version: v0
servers:
  - url: https://api.siit.io
security: []
paths:
  /v1/articles/categories:
    get:
      tags:
        - Article
      summary: List Categories
      description: >-
        Fetch Article categories. The response includes both top-level
        categories and subcategories; use `parent` to reconstruct the hierarchy,
        or filter with `parent_category` / `root_only`.
      parameters:
        - $ref: '#/components/parameters/expand_param'
        - name: page
          in: query
          required: false
          description: The current page
          schema:
            type: integer
        - name: per_page
          in: query
          required: false
          description: Number of results retrieved per page.
          schema:
            type: integer
        - name: parent_category
          in: query
          schema:
            type: string
          required: false
          description: >-
            Return only categories whose parent matches this UID. Useful to
            fetch the direct children of a given category. Cannot be combined
            with `root_only`.
        - name: root_only
          in: query
          schema:
            type: boolean
            default: false
          required: false
          description: >-
            When true, return only top-level categories (those without a
            parent). Cannot be combined with `parent_category`.
      responses:
        '200':
          description: Successful
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/knowledge_categories_paged_object'
      security:
        - bearer: []
components:
  parameters:
    expand_param:
      name: expand[]
      in: query
      schema:
        type: array
        items:
          type: string
      description: >-
        Fields to expand into full objects. Example:
        ?expand[]=assignee_admin&expand[]=tags
      required: false
  schemas:
    knowledge_categories_paged_object:
      type: object
      properties:
        meta:
          $ref: '#/components/schemas/meta_object'
        results:
          type: array
          items:
            $ref: '#/components/schemas/knowledge_category'
    meta_object:
      type: object
      properties:
        count:
          type: integer
        current_page:
          type: integer
        next_page_link:
          type: string
          nullable: true
        per_page:
          type: integer
          default: 20
          maximum: 200
        previous_page_link:
          type: string
          nullable: true
        total:
          type: integer
    knowledge_category:
      type: object
      readOnly: true
      properties:
        uid:
          type: string
          readOnly: true
          description: The UID of the Article Category
        name:
          type: string
          description: The name of the Article Category
        parent:
          oneOf:
            - type: string
              description: UID when not expanded
            - $ref: '#/components/schemas/knowledge_category'
          description: >-
            The parent Article Category (null for top-level categories). Pass
            `?expand[]=field_name` for full object.
          nullable: true
          readOnly: true
  securitySchemes:
    bearer:
      type: http
      scheme: bearer

````