openapi: 3.0.0
info:
  title: Callback Example
  version: 1.0.0
paths:
  /streams:
    post:
      description: subscribes a client to receive out-of-band data
      parameters:
        - name: callbackUrl
          in: query
          required: true
          description: |
            the location where data will be sent.  Must be network accessible
            by the source server
          schema:
            type: string
            format: uri
            example: https://tonys-server.com
      responses:
        '201':
          description: subscription successfully created
          content:
            application/json:
              schema:
                description: subscription information
                required:
                  - subscriptionId
                properties:
                  subscriptionId:
                    description: this unique identifier allows management of the subscription
                    type: string
                    example: 2531329f-fb09-4ef7-887e-84e648214436
      callbacks:
        # the name `onData` is a convenience locator
        onData:
          $ref: '#/components/callbacks/onData'
components:
  callbacks:
    onData:
      # when data is sent, it will be sent to the `callbackUrl` provided
      # when making the subscription PLUS the suffix `/data`
      '{$request.query.callbackUrl}/data':
        post:
          requestBody:
            description: subscription payload
            content:
              application/json:
                schema:
                  properties:
                    timestamp:
                      type: string
                      format: date-time
                    userData:
                      type: string
          responses:
            '202':
              description: |
                Your server implementation should return this HTTP status code
                if the data was received successfully
            '204':
              description: |
                Your server should return this HTTP status code if no longer interested
                in further updates
