Optional property per operation

[marcortw]

I am trying to reuse a schema similar to the 'reusable bodies' section described here, with the difference that I'd like to reuse the same schema in the requestBody and in the response:

  /pets:
    post:
      summary: Creates a new pet
      requestBody:
        content:
          '*/*':
            schema:
              $ref: '#/components/schemas/PetBody'
        required: true
      responses:
        200:
          description: successful operation
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/PetBody'

This works, but I'd like to make an exception for an 'id' property of the PetBody. Assuming that a Pet's unique identifier gets created after the POST on the server, I wonder how I could split or compose the PetBody schema such that an 'id' could be marked required: true only in the response?

Something like this works, but I'd also like to reference the id parameter and possibly a few more through additional references which doesn't seem to work according to #1467

    PetBodyResponse:
      allOf:
        - $ref: '#/components/schemas/PetBody'
        - type: object
          properties:
            id:
              type: string

Thanks in advance for any good suggestions,
Marco

[hkosova]

There's no need for separate schemas. You can use a single PetBody schema and define id as required and readOnly: true:

Declares the property as "read only". This means that it MAY be sent as part of a response but SHOULD NOT be sent as part of the request. If the property is marked as readOnly being true and is in the required list, the required will take effect on the response only.

[marcortw]

Great, this is exactly what I needed! Thank you very much for the hint.