Representational State Transfer (передача репрезентативного состояния)
не прижилось
https://swagger.io/specification/
openapi: "3.0.0"
info:
  version: 1.0.0
  title: Test API
paths:
    ...
paths:
  /hello:
    get:
      summary: Say hello
      operationId: hello
      parameters:
        - name: user
          in: query
          description: User name to appear in greetings
          required: false
          schema:
            type: string
            default: 'world'
      responses:
        '200':
          description: Greeting
          content:
            'text/plain':
               schema:
                 type: "string"