openapi: 3.1.0
info:
  title: Qlik Sense Enterprise Qlik Sense Service About Load Balancing API
  description: REST API for retrieving product information about a Qlik Sense site, including system details, installed components, external URLs, and third-party software information. The About Service API provides read-only endpoints that return JSON-formatted information about the Qlik Sense deployment.
  version: 2025.11.0
  contact:
    name: Qlik Support
    url: https://community.qlik.com/
  license:
    name: Proprietary
    url: https://www.qlik.com/us/legal/terms-of-use
  x-providerName: Qlik
  x-serviceName: qlik-sense-about-service
servers:
- url: https://{server}/api/about/v1
  description: About Service API via HTTPS
  variables:
    server:
      default: localhost
      description: Qlik Sense server hostname
security:
- xrfkey: []
tags:
- name: Load Balancing
  description: Engine load balancing decisions for distributing app sessions across Qlik Sense Engine Services
paths:
  /loadbalancing/prioritize:
    post:
      operationId: prioritizeLoadBalancing
      summary: Qlik Sense Enterprise Prioritize engine services for load balancing
      description: Prioritizes Qlik Sense Engine Services (QES) for a user and an app. The Load Balancing module makes load balancing decisions for engine sessions to distribute load across available engine services.
      tags:
      - Load Balancing
      parameters:
      - $ref: '#/components/parameters/XrfKeyParam'
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/LoadBalancingRequest'
      responses:
        '200':
          description: Engine service prioritization returned successfully
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/LoadBalancingResult'
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
components:
  schemas:
    LoadBalancingResult:
      type: object
      properties:
        engineServices:
          type: array
          items:
            $ref: '#/components/schemas/EngineServicePriority'
          description: Prioritized list of engine services
    EngineServicePriority:
      type: object
      properties:
        engineId:
          type: string
          format: uuid
          description: Engine service identifier
        hostName:
          type: string
          description: Hostname of the engine node
        port:
          type: integer
          description: Port of the engine service
        priority:
          type: integer
          description: Priority ranking (lower is higher priority)
        isAppOpen:
          type: boolean
          description: Whether the app is already open on this engine
    LoadBalancingRequest:
      type: object
      properties:
        userDirectory:
          type: string
          description: User directory name
        userId:
          type: string
          description: User identifier
        appId:
          type: string
          format: uuid
          description: Application ID to load balance for
      required:
      - userDirectory
      - userId
      - appId
    Error:
      type: object
      properties:
        message:
          type: string
          description: Human-readable error message
  responses:
    Unauthorized:
      description: Authentication failed or Xrfkey missing/mismatched.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    BadRequest:
      description: Invalid request parameters or body.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  parameters:
    XrfKeyParam:
      name: Xrfkey
      in: query
      required: true
      description: Cross-site request forgery prevention key. Must be 16 arbitrary characters matching the X-Qlik-Xrfkey header value.
      schema:
        type: string
        minLength: 16
        maxLength: 16
  securitySchemes:
    xrfkey:
      type: apiKey
      in: header
      name: X-Qlik-Xrfkey
      description: Cross-site request forgery prevention key. Must be 16 arbitrary characters and must match the Xrfkey query parameter.