openapi: 3.0.3
info:
  title: IQAir AirVisual Cities Rankings API
  description: The IQAir AirVisual API provides real-time and forecast air quality and weather data worldwide. It offers endpoints for listing supported countries, states, and cities, retrieving air quality data for specific locations or nearest stations, and ranking cities by air quality index.
  version: 2.0.0
  contact:
    name: IQAir
    url: https://www.iqair.com
servers:
- url: https://api.airvisual.com/v2
  description: IQAir AirVisual API v2
security:
- apiKey: []
tags:
- name: Rankings
  description: City air quality rankings
paths:
  /city_ranking:
    get:
      tags:
      - Rankings
      summary: Get city air quality ranking
      description: Returns a sorted array of major cities worldwide ranked from highest to lowest AQI.
      operationId: getCityRanking
      parameters:
      - name: key
        in: query
        required: true
        description: Your API key
        schema:
          type: string
      responses:
        '200':
          description: Successful response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/CityRankingResponse'
        '400':
          description: Bad request
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '401':
          description: Unauthorized
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '429':
          description: Rate limit exceeded
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
components:
  schemas:
    ErrorResponse:
      type: object
      properties:
        status:
          type: string
          example: fail
        data:
          type: object
          properties:
            message:
              type: string
              description: Error message
    CityRankingResponse:
      type: object
      properties:
        status:
          type: string
          example: success
        data:
          type: array
          items:
            type: object
            properties:
              city:
                type: string
              state:
                type: string
              country:
                type: string
              ranking:
                type: object
                properties:
                  current_aqi:
                    type: integer
                    description: Current AQI based on US EPA standard
                  current_aqi_cn:
                    type: integer
                    description: Current AQI based on China MEP standard
  securitySchemes:
    apiKey:
      type: apiKey
      in: query
      name: key
      description: API key passed as a query parameter.