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
  include Pagination

  def index
    @examples = Example.order(id: :desc)
    render json: { pagination: paginate(@examples), examples: @examples }
  end
end

pagination.rb

module Pagination
  include ActionDispatch::Routing::UrlFor

  def paginate(active_relation)
    routes = Routes.new(this, active_relation)
    {
      records:       active_relation.count,
      total_records: active_relation.total_count,
      current_page:  active_relation.current_page,
      total_pages:   active_relation.total_pages,
      first_page:    routes.first_page,
      last_page:     routes.last_page,
      prev_page:     routes.prev_page,
      next_page:     routes.next_page,
    }
  end

  class Routes
    def initialize(controller, active_relation)
      @controller = controller
      @active_relation = active_relation
    end
    
    def first_page
      @controller.url_for(params.merge(page: 1))
    end

    def last_page
      @controller.url_for(params.merge(page: @active_relation.total_pages))
    end

    def prev_page
      @controller.url_for(params.merge(page: @active_relation.prev_page)) unless @active_relation.first_page?
    end

    def next_page
      @controller.url_for(params.merge(page: @active_relation.next_page)) unless @active_relation.last_page?
    end
  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
      }
    ]
}