OpenApi with external files

openapi.yaml

openapi: 3.0.3
info:
  title: Example API v2 - API Reference
  description: ""
  contact:
    name: Fatture in Cloud
    url: 'https://www.example.it'
    email: info@example.it
  license:
    name: ''
    url: 'https://www.example.it'
  version: v2.0.0
servers:
  - url: 'https://api-v2.example.it'
tags:
  - name: User
paths:
  /user/info:
    get:
      tags:
        - User
      summary: Get User Info
      responses:
        '200':
          $ref: '#/components/responses/UserInfoResponse'
        '401':
          description: Unauthorized.
      operationId: getUserInfo
      description: "Makes possible to retrieve the current user's info."
      security:
        - OAuth2AuthenticationCodeFlow: []
      parameters: []
components:
  schemas: {}
  securitySchemes:
    OAuth2AuthenticationCodeFlow:
      type: oauth2
      flows:
        authorizationCode:
          tokenUrl: 'https://api-v2.example.it/oauth/token'
          refreshUrl: 'https://api-v2.example.it/oauth/token'
          scopes:
            'entity.clients:r': ''
          authorizationUrl: 'https://api-v2.example.it/oauth/authorize'
  responses:
    UserInfoResponse:
      description: User info.
      content:
        application/json:
          schema:
            $ref: ./models/responses/UserInfoResponse.yaml
security:
  - OAuth2AuthenticationCodeFlow: []

User.yaml

type: object
description: User infos.
properties:
  id:
    type: integer
    example: 12345
    description: User unique identifier
  name:
    type: string
    description: Full name of the user.
    nullable: true
    example: Mario Rossi
  first_name:
    type: string
    nullable: true
    example: Mario
    description: First name of the user.
  last_name:
    type: string
    nullable: true
    example: Rossi
    description: Last name of the user.
  email:
    type: string
    example: mario.rossi@example.com
    description: Email of the user.
  hash:
    type: string
    example: 5add29e1234532a1bf2ed7b612043029
  picture:
    type: string
    nullable: true
    example: picture.jpg
    description: Picture of the user.

UserInfoResponse.yaml

description: The UserInfo response.
type: object
properties:
  data:
    $ref: ../schemas/User.yaml
  info:
    type: object
    properties:
      need_marketing_consents_confirmation:
        type: boolean
      need_password_change:
        type: boolean
      need_terms_of_service_confirmation:
        type: boolean
  email_confirmation_state:
    type: object
    properties:
      need_confirmation:
        type: boolean