Include this in controllers and render with your JSON to get pagination URLs matching http://jsonapi.org/format/#fetching-pagination specification. Requires that you use https://github.com/amatsuda/kaminari

controller_example.rb

class ExamplesController < ApplicationController
  def index
    @examples = Example.order(id: :desc)
    render json: { pagination: paginate(@examples), examples: @examples }
  end
  
  private
  
  def paginate(active_relation)
    Pagination.for(self, active_relation)
  end
end

pagination.rb

class Pagination
  def self.for(controller, active_relation)
    new(controller, active_relation).paginate
  end

  attr_reader :controller, :active_relation

  delegate :params, :url_for, to: :controller
  delegate :count, :total_count, :current_page, :total_pages, 
    :prev_page, :next_page, :first_page?, :last_page?, to: :active_relation

  def initialize(controller, active_relation)
    @controller      = controller
    @active_relation = active_relation
  end

  def first_page_url
    url_for(params.merge(page: 1))
  end

  def last_page_url
    url_for(params.merge(page: total_pages))
  end

  def prev_page_url
    url_for(params.merge(page: prev_page)) unless first_page?
  end

  def next_page_url
    url_for(params.merge(page: next_page)) unless last_page?
  end

  def paginate
    {
      records:       count,
      total_records: total_count,
      current_page:  current_page,
      total_pages:   total_pages,
      first_page:    first_page_url,
      last_page:     last_page_url,
      prev_page:     prev_page_url,
      next_page:     next_page_url,
    }
  end
end

response.json

{
  "pagination": {
    "records": 5,
    "total_records": 21,
    "current_page": 1,
    "total_pages": 5,
    "first_page": "http://example.com/examples?page=1&per_page=5",
    "last_page": "http://example.com/examples?page=5&per_page=5",
    "prev_page": null,
    "next_page": "http://example.com/examples?page=2&per_page=5"
  },
  "examples": [
      {
        "id": 1
      },
      {
        "id": 2
      },
      {
        "id": 3
      },
      {
        "id": 4
      },
      {
        "id": 5
      }
    ]
}