openapi: 3.0.3
info:
  title: Hello API
  description: Defines an example “Hello World” API
  version: "0.0.1"
paths:
  "/":
    get:
      operationId: sayHello
      summary: Say Hello
      description: Prints out a greeting
      parameters:
      - name: name
        in: query
        required: false
        schema:
          type: string
          default: "World"
      responses:
        "200":
          description: Successful response
          content:
            "application/json":
              schema:
                $ref: "#/components/schemas/HelloResponse"

components:
  schemas:
    HelloResponse:
      description: Response body
      type: object
      properties:
        message:
          type: string
          description: Greeting
          example: Hello World!