openapi: 3.0.0
info:
  title: Example of links with callbacks
  version: 0.9.0
paths:
  /longrunning-thing:
    post: 
      parameters:
        name: heartbeat-url
        in: query
        schema:
          type: string
          format: uri
      requestBody:
        content:
          application/json:
            schema:
              type: object
              properties:
                failedUrl:
                  type: string
                successUrl:
                  type: string
      responses:
        '200': 
          description: Long running thing initiated
      callbacks:
        heartbeat:
          '$request.query.heartbeat-url':
            post:
              requestBody:
                $ref: '#/components/requestBodies/heartbeatMessage'
              responses:
                '200':
                  description: Consumer acknowledged the callback   
        failed:
          '$response.body#/failedUrl':
            post:
              requestBody:
                $ref: '#/components/requestBodies/failedMessage'
              responses:
                '200':
                  description: Consumer acknowledged the callback   
        success:
          '$response.body#/successUrl':
            post:
              requestBody:
                $ref: '#/components/requestBodies/successMessage'
              responses:
                '200':
                  description: Consumer acknowledged the callback