World Air Quality Index (WAQI) Search API

openapi: 3.1.0
info:
  title: World Air Quality Index (WAQI) JSON Feed Search API
  description: The WAQI JSON API provides real-time air quality data, AQI readings, pollutant measurements, and station data for more than 12,000 monitoring stations worldwide. It delivers city-level and station-level air quality index values for pollutants including PM2.5, PM10, NO2, CO, SO2, and Ozone, along with geo-location queries, weather conditions, and 3-8 day forecast data. Authentication requires a free token obtained from the Air Quality Open Data Platform.
  version: 1.0.0
  contact:
    name: WAQI Support
    url: https://aqicn.org/api/
  license:
    name: Non-Commercial Use
    url: https://aqicn.org/api/
  termsOfService: https://aqicn.org/api/
servers:
- url: https://api.waqi.info
  description: WAQI Production API
security:
- tokenAuth: []
tags:
- name: Search
  description: Search for monitoring stations by keyword
paths:
  /search/:
    get:
      operationId: searchStations
      summary: Search for monitoring stations by keyword
      description: Searches for air quality monitoring stations by name or keyword, including native language names. Returns a list of matching stations with their AQI values and location details.
      tags:
      - Search
      parameters:
      - name: keyword
        in: query
        required: true
        description: Search keyword — station name or any name referring to the station, including native language names.
        schema:
          type: string
          example: Johannesburg
      - name: token
        in: query
        required: true
        description: API authentication token.
        schema:
          type: string
          example: demo
      responses:
        '200':
          description: Successful response with list of matching monitoring stations
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SearchResponse'
              example:
                status: ok
                data:
                - uid: 8397
                  aqi: '68'
                  time:
                    stime: '2024-01-15 12:00:00'
                    vtime: 1705320000
                  station:
                    name: Johannesburg South, South Africa
                    geo:
                    - -26.2041
                    - 28.0473
                    url: johannesburg-south/south-africa
                    country: ZA
        '400':
          description: Missing or invalid keyword
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '401':
          description: Invalid or missing API token
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
components:
  schemas:
    StationInfo:
      type: object
      description: Information about a monitoring station
      properties:
        name:
          type: string
          description: Full station name including city and country
          example: Johannesburg South, South Africa
        geo:
          type: array
          description: Geographic coordinates [latitude, longitude]
          items:
            type: number
            format: float
          minItems: 2
          maxItems: 2
          example:
          - -26.2041
          - 28.0473
        url:
          type: string
          description: Relative URL path to the station page on aqicn.org
          example: johannesburg-south/south-africa
        country:
          type: string
          description: ISO 3166-1 alpha-2 country code
          example: ZA
      required:
      - name
      - geo
      - url
    SearchResponse:
      type: object
      description: Response from the station search endpoint
      properties:
        status:
          type: string
          enum:
          - ok
          - error
          description: Response status indicator
        data:
          type: array
          description: List of matching monitoring stations
          items:
            $ref: '#/components/schemas/SearchResult'
      required:
      - status
      - data
    ErrorResponse:
      type: object
      description: Error response returned when a request fails
      properties:
        status:
          type: string
          enum:
          - error
          description: Always 'error' for error responses
        data:
          type: string
          description: Human-readable error message
          example: Unknown city or station
      required:
      - status
      - data
    SearchResult:
      type: object
      description: A single monitoring station search result
      properties:
        uid:
          type: integer
          description: Unique station identifier in the WAQI network
          example: 8397
        aqi:
          type: string
          description: Current AQI value (may be a string '-' if unavailable)
          example: '68'
        time:
          type: object
          properties:
            stime:
              type: string
              description: Station local time string
              example: '2024-01-15 12:00:00'
            vtime:
              type: integer
              description: Unix epoch timestamp
              example: 1705320000
        station:
          $ref: '#/components/schemas/StationInfo'
      required:
      - uid
      - aqi
      - station
  securitySchemes:
    tokenAuth:
      type: apiKey
      in: query
      name: token
      description: API token obtained from the Air Quality Open Data Platform at https://aqicn.org/data-platform/token/
externalDocs:
  description: WAQI JSON API Documentation
  url: https://aqicn.org/json-api/doc/