openapi: 3.0.3
info:
  title: WHMCS Authentication Domains API
  description: The WHMCS API provides an interface to perform operations and actions within WHMCS from external applications and scripts. It supports client management, billing, orders, domain management, support tickets, and system administration.
  version: 1.0.0
  contact:
    name: WHMCS Developer Documentation
    url: https://developers.whmcs.com/api/
  license:
    name: WHMCS License
    url: https://www.whmcs.com/license/
servers:
- url: https://{your-domain}/includes/api.php
  description: WHMCS API endpoint (self-hosted installation)
  variables:
    your-domain:
      default: example.com
      description: Your WHMCS installation domain
security:
- ApiCredentials: []
tags:
- name: Domains
  description: Domain registration and management
paths:
  /?action=DomainRegister:
    post:
      operationId: domainRegister
      summary: Domain Register
      description: Register a new domain via WHMCS.
      tags:
      - Domains
      requestBody:
        required: true
        content:
          application/x-www-form-urlencoded:
            schema:
              allOf:
              - $ref: '#/components/schemas/AuthCredentials'
              - type: object
                required:
                - domainid
                properties:
                  domainid:
                    type: integer
                    description: The ID of the domain to register.
      responses:
        '200':
          description: Domain registration initiated.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SuccessResponse'
  /?action=DomainWhois:
    post:
      operationId: domainWhois
      summary: Domain WHOIS
      description: Perform a WHOIS lookup on a domain.
      tags:
      - Domains
      requestBody:
        required: true
        content:
          application/x-www-form-urlencoded:
            schema:
              allOf:
              - $ref: '#/components/schemas/AuthCredentials'
              - type: object
                required:
                - domain
                properties:
                  domain:
                    type: string
                    description: The domain to perform the WHOIS lookup for.
      responses:
        '200':
          description: WHOIS lookup results.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/DomainWhoisResponse'
components:
  schemas:
    DomainWhoisResponse:
      type: object
      properties:
        result:
          type: string
        domain:
          type: string
        status:
          type: string
          description: Registration status of the domain.
    SuccessResponse:
      type: object
      properties:
        result:
          type: string
          enum:
          - success
          - error
          description: Operation result status.
        message:
          type: string
          description: Descriptive result message.
    AuthCredentials:
      type: object
      required:
      - identifier
      - secret
      - responsetype
      properties:
        identifier:
          type: string
          description: API credential identifier.
        secret:
          type: string
          description: API credential secret key.
        responsetype:
          type: string
          enum:
          - json
          - xml
          default: json
          description: Response format type.
  securitySchemes:
    ApiCredentials:
      type: apiKey
      in: query
      name: identifier
      description: WHMCS API credentials. Provide identifier and secret parameters in the POST request body, along with the action parameter.