petstore.yaml

openapi: 3.0.0
info:
  title: Pet Store API
  version: 1.0.0
paths:
  /pets:
    post:
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/Pet'
      responses:
        '200':
          description: The response for Pets post operation.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Pet'

components:
  schemas:
    Pet:
      type: object
      required:
      - petType
      properties:
        petType:
          type: string
      discriminator:
        propertyName: petType

    Cat:
      allOf:
      - $ref: '#/components/schemas/Pet'
      - type: object
        # all other properties specific to a `Cat`
        properties:
          name:
            type: string
    Dog:
      allOf:
      - $ref: '#/components/schemas/Pet'
      - type: object
        # all other properties specific to a `Dog`
        properties:
          bark:
            type: string
    Lizard:
      allOf:
      - $ref: '#/components/schemas/Pet'
      - type: object
        # all other properties specific to a `Lizard`
        properties:
          lovesRocks:
            type: boolean