openapi: 3.0.3
info:
  title: writeOnly repro
  version: 1.0.0
paths:
  /items:
    post:
      operationId: item_create
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/CreateItemRequest'
      responses:
        '201':
          description: Created
components:
  schemas:
    CreateItemRequest:
      type: object
      required:
        - payload
      properties:
        payload:
          $ref: '#/components/schemas/Payload'
    Payload:
      type: object
      required:
        - kind
        - encoded
      properties:
        kind:
          type: string
          enum: [jpeg]
        encoded:
          type: string
          writeOnly: true
          description: Data required on write