openapi: 3.0.0
info:
  title: Body Narrowing Test API
  version: 1.0.0
paths:
  /test:
    post:
      requestBody:
        content:
          application/json:
            schema:
              oneOf:
                - type: object
                - type: array
                - type: string
      responses:
        '200':
          description: Success
          content:
            application/json:
              schema:
                anyOf:
                  - type: string
                  - type: integer
                  - type: boolean