get:
  tags:
    - posts
  summary: get post index
  description: This operation retrieves a post's index relative to its topic
  parameters:
    - in: path
      name: pid
      schema:
        type: string
      required: true
      description: a valid post id
      example: 2
  responses:
    '200':
      description: Post index successfully retrieved.
      content:
        application/json:
          schema:
            type: object
            properties:
              status:
                $ref: ../../../components/schemas/Status.yaml#/Status
              response:
                type: object
                properties:
                  index:
                    type: number