openapi: 3.1.0
info:
  title: Demo API
  version: 1.0.0
paths:
  /foo:
    get:
      parameters:
        - in: query
          name: filter
          required: false
      responses:
        "200":
          description: ok
          content:
            application/json:
              schema:
                type: string
  /baz:
    post:
      requestBody:
        required: false
        content:
          application/json:
            schema:
              type: object
      responses:
        "201":
          description: created