openapi: 3.0.0
info:
  title: Circular AdditionalProperties
  version: 1.0.0
paths: {}
components:
  schemas:
    BaseSchema:
      type: object
      allOf:
        - type: object
          properties:
            fixedProperty:
              type: string
      properties:
        prop1:
          type: object
          additionalProperties:
            $ref: '#/components/schemas/BaseSchema'