openapi: 3.1.0
info:
  title: AQICN JSON Air Quality API
  description: |
    Real-time and forecast air quality data from 11,000+ monitoring stations globally.
    Returns AQI measurements for PM2.5, PM10, NO2, CO, SO2, and ozone pollutants.
    Authentication requires a free API token from https://aqicn.org/data-platform/token/

    Data is provided by the World Air Quality Index project (AQICN) for non-commercial use.
    Rate limit: 1,000 requests per second.
  version: "1.0.0"
  contact:
    url: https://aqicn.org/faq/
  license:
    name: Non-Commercial Use Only
    url: https://aqicn.org/api/tos/
  x-generated-from: documentation

servers:
- url: https://api.waqi.info
  description: AQICN Production API

security:
- TokenAuth: []

components:
  securitySchemes:
    TokenAuth:
      type: apiKey
      in: query
      name: token
      description: API token obtained from https://aqicn.org/data-platform/token/

  schemas:
    AQIStation:
      type: object
      description: Air quality monitoring station with current readings
      properties:
        status:
          type: string
          description: Response status (ok or error)
          example: ok
        data:
          $ref: '#/components/schemas/StationData'

    StationData:
      type: object
      description: Station data including AQI and pollutant readings
      properties:
        aqi:
          type: integer
          description: Overall Air Quality Index value
          example: 45
        idx:
          type: integer
          description: Station ID in AQICN database
          example: 8502
        city:
          $ref: '#/components/schemas/CityInfo'
        time:
          $ref: '#/components/schemas/TimeInfo'
        iaqi:
          $ref: '#/components/schemas/PollutantData'
        forecast:
          $ref: '#/components/schemas/ForecastData'
        attributions:
          type: array
          description: Data source attributions
          items:
            $ref: '#/components/schemas/Attribution'

    CityInfo:
      type: object
      description: City and location information for the station
      properties:
        name:
          type: string
          description: City and station name
          example: Beijing, China
        url:
          type: string
          format: uri
          description: Station URL on AQICN
          example: https://aqicn.org/city/beijing/
        geo:
          type: array
          description: Geographic coordinates [latitude, longitude]
          items:
            type: number
          example: [39.9042, 116.4074]

    TimeInfo:
      type: object
      description: Timestamp information for the reading
      properties:
        s:
          type: string
          description: ISO 8601 timestamp of measurement
          example: "2025-04-19 10:00:00"
        tz:
          type: string
          description: Station timezone
          example: "+08:00"
        v:
          type: integer
          description: Unix timestamp
          example: 1745056800

    PollutantData:
      type: object
      description: Individual pollutant AQI values
      properties:
        pm25:
          type: object
          description: PM2.5 AQI reading
          properties:
            v: {type: number, example: 45}
        pm10:
          type: object
          description: PM10 AQI reading
          properties:
            v: {type: number, example: 32}
        no2:
          type: object
          description: Nitrogen dioxide AQI reading
          properties:
            v: {type: number, example: 12}
        o3:
          type: object
          description: Ozone AQI reading
          properties:
            v: {type: number, example: 28}
        so2:
          type: object
          description: Sulfur dioxide AQI reading
          properties:
            v: {type: number, example: 5}
        co:
          type: object
          description: Carbon monoxide AQI reading
          properties:
            v: {type: number, example: 8}

    ForecastData:
      type: object
      description: Multi-day air quality and weather forecast
      properties:
        daily:
          type: object
          description: Daily forecasts by pollutant
          properties:
            pm25:
              type: array
              description: PM2.5 daily forecast values
              items:
                $ref: '#/components/schemas/ForecastDay'
            pm10:
              type: array
              items:
                $ref: '#/components/schemas/ForecastDay'
            o3:
              type: array
              items:
                $ref: '#/components/schemas/ForecastDay'
            uvi:
              type: array
              items:
                $ref: '#/components/schemas/ForecastDay'

    ForecastDay:
      type: object
      description: Single-day forecast value
      properties:
        avg:
          type: integer
          description: Average AQI for the day
          example: 52
        day:
          type: string
          description: Date string
          example: "2025-04-20"
        max:
          type: integer
          description: Maximum AQI for the day
          example: 78
        min:
          type: integer
          description: Minimum AQI for the day
          example: 31

    Attribution:
      type: object
      description: Data source attribution
      properties:
        url:
          type: string
          format: uri
          description: Attribution URL
          example: https://www.epa.gov/airnow
        name:
          type: string
          description: Data source name
          example: "US EPA AirNow"

    StationSearchResult:
      type: object
      description: Station search result
      properties:
        status:
          type: string
          example: ok
        data:
          type: array
          description: List of matching stations
          items:
            type: object
            properties:
              uid:
                type: integer
                description: Station unique ID
                example: 8502
              aqi:
                type: string
                description: Current AQI value or "N/A"
                example: "45"
              station:
                type: object
                properties:
                  name:
                    type: string
                    description: Station name
                    example: "Beijing, China"
                  geo:
                    type: array
                    items:
                      type: number

    ErrorResponse:
      type: object
      description: Error response
      properties:
        status:
          type: string
          example: error
        data:
          type: string
          description: Error message
          example: "Invalid key"

paths:
  /feed/geo:{lat};{lng}/:
    get:
      operationId: getAQIByGeoCoordinates
      summary: Air Quality Programmatic APIs AQICN Get AQI by Geographic Coordinates
      description: Retrieve real-time air quality data for the nearest monitoring station to given latitude and longitude coordinates.
      tags: [Stations, Geolocation]
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
      parameters:
      - name: lat
        in: path
        required: true
        description: Latitude coordinate
        schema:
          type: number
        example: 39.9042
      - name: lng
        in: path
        required: true
        description: Longitude coordinate
        schema:
          type: number
        example: 116.4074
      - name: token
        in: query
        required: true
        description: API authentication token
        schema:
          type: string
        example: demo
      responses:
        '200':
          description: Air quality data for nearest station
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AQIStation'
              examples:
                getAQIByGeoCoordinates200Example:
                  summary: Default getAQIByGeoCoordinates 200 response
                  x-microcks-default: true
                  value:
                    status: ok
                    data:
                      aqi: 45
                      idx: 8502
                      city:
                        name: "Beijing, China"
                        url: "https://aqicn.org/city/beijing/"
                        geo: [39.9042, 116.4074]
        '200_error':
          description: Error response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'

  /feed/{city}/:
    get:
      operationId: getAQIByCity
      summary: Air Quality Programmatic APIs AQICN Get AQI by City Name
      description: Retrieve real-time air quality data for a city by name. City names follow AQICN URL conventions (e.g., "beijing", "london", "new-york").
      tags: [Stations, Cities]
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
      parameters:
      - name: city
        in: path
        required: true
        description: City name or station ID
        schema:
          type: string
        example: beijing
      - name: token
        in: query
        required: true
        description: API authentication token
        schema:
          type: string
        example: demo
      responses:
        '200':
          description: Air quality data for the city
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AQIStation'
              examples:
                getAQIByCity200Example:
                  summary: Default getAQIByCity 200 response
                  x-microcks-default: true
                  value:
                    status: ok
                    data:
                      aqi: 87
                      idx: 1451
                      city:
                        name: "Shanghai, China"

  /feed/ip/:
    get:
      operationId: getAQIByIP
      summary: Air Quality Programmatic APIs AQICN Get AQI by IP Geolocation
      description: Retrieve air quality data for the location nearest to the client's IP address using IP geolocation.
      tags: [Stations, Geolocation]
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
      parameters:
      - name: token
        in: query
        required: true
        description: API authentication token
        schema:
          type: string
        example: demo
      responses:
        '200':
          description: Air quality data for IP-geolocated nearest station
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AQIStation'
              examples:
                getAQIByIP200Example:
                  summary: Default getAQIByIP 200 response
                  x-microcks-default: true
                  value:
                    status: ok
                    data:
                      aqi: 32
                      idx: 5678

  /search/:
    get:
      operationId: searchStations
      summary: Air Quality Programmatic APIs AQICN Search Monitoring Stations
      description: Search for air quality monitoring stations by keyword, city name, or station name.
      tags: [Stations, Search]
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
      parameters:
      - name: keyword
        in: query
        required: true
        description: Search keyword (city or station name)
        schema:
          type: string
        example: London
      - name: token
        in: query
        required: true
        description: API authentication token
        schema:
          type: string
        example: demo
      responses:
        '200':
          description: List of matching stations
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/StationSearchResult'
              examples:
                searchStations200Example:
                  summary: Default searchStations 200 response
                  x-microcks-default: true
                  value:
                    status: ok
                    data:
                    - uid: 5724
                      aqi: "42"
                      station:
                        name: "London, United Kingdom"
                        geo: [51.5074, -0.1278]

  /map/bounds/:
    get:
      operationId: getStationsInBounds
      summary: Air Quality Programmatic APIs AQICN Get Stations Within Map Bounds
      description: Retrieve all monitoring stations and their current AQI values within a geographic bounding box. Useful for map overlays.
      tags: [Stations, Map]
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
      parameters:
      - name: latlng
        in: query
        required: true
        description: Bounding box as lat1,lng1,lat2,lng2
        schema:
          type: string
        example: "35.0,115.0,42.0,125.0"
      - name: networks
        in: query
        required: false
        description: Filter by network (all, china, us, etc.)
        schema:
          type: string
        example: all
      - name: token
        in: query
        required: true
        description: API authentication token
        schema:
          type: string
        example: demo
      responses:
        '200':
          description: Stations within the bounding box
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/StationSearchResult'
              examples:
                getStationsInBounds200Example:
                  summary: Default getStationsInBounds 200 response
                  x-microcks-default: true
                  value:
                    status: ok
                    data:
                    - uid: 1451
                      aqi: "87"
                      station:
                        name: "Shanghai, China"