diff --git a/github_changelog_generator.gemspec b/github_changelog_generator.gemspec
index d9f2074..d6e1f35 100644
--- a/github_changelog_generator.gemspec
+++ b/github_changelog_generator.gemspec
@@ -27,4 +27,5 @@ Gem::Specification.new do |spec|
   spec.add_runtime_dependency "rake", ">= 10.0"
   spec.add_runtime_dependency "github_api", ">= 0.14"
   spec.add_runtime_dependency "rainbow", ">= 2.1"
+  spec.add_runtime_dependency("octokit", ["~> 4.0"])
 end
diff --git a/lib/github_changelog_generator.rb b/lib/github_changelog_generator.rb
index c478be5..44b584c 100755
--- a/lib/github_changelog_generator.rb
+++ b/lib/github_changelog_generator.rb
@@ -2,6 +2,7 @@
 # frozen_string_literal: true
 
 require "github_api"
+require "octokit"
 require "json"
 require "benchmark"
 
diff --git a/lib/github_changelog_generator/generator/generator.rb b/lib/github_changelog_generator/generator/generator.rb
index 9f7a9bf..8a9003f 100644
--- a/lib/github_changelog_generator/generator/generator.rb
+++ b/lib/github_changelog_generator/generator/generator.rb
@@ -1,5 +1,6 @@
 # frozen_string_literal: true
 require_relative "../fetcher"
+require_relative "../octo_fetcher"
 require_relative "generator_generation"
 require_relative "generator_fetcher"
 require_relative "generator_processor"
@@ -21,7 +22,7 @@ module GitHubChangelogGenerator
     def initialize(options = nil)
       @options = options || {}
       @tag_times_hash = {}
-      @fetcher = GitHubChangelogGenerator::Fetcher.new @options
+      @fetcher = GitHubChangelogGenerator::OctoFetcher.new @options
     end
 
     def fetch_issues_and_pr
diff --git a/lib/github_changelog_generator/octo_fetcher.rb b/lib/github_changelog_generator/octo_fetcher.rb
new file mode 100644
index 0000000..3b4b207
--- /dev/null
+++ b/lib/github_changelog_generator/octo_fetcher.rb
@@ -0,0 +1,293 @@
+module GitHubChangelogGenerator
+  # A Fetcher responsible for all requests to GitHub and all basic manipulation with related data
+  # (such as filtering, validating, e.t.c)
+  #
+  # Example:
+  # fetcher = GitHubChangelogGenerator::Fetcher.new options
+
+  class OctoFetcher
+    PER_PAGE_NUMBER   = 100
+    MAX_THREAD_NUMBER = 50
+    CHANGELOG_GITHUB_TOKEN = "CHANGELOG_GITHUB_TOKEN"
+    GH_RATE_LIMIT_EXCEEDED_MSG = "Warning: Can't finish operation: GitHub API rate limit exceeded, change log may be " \
+    "missing some issues. You can limit the number of issues fetched using the `--max-issues NUM` argument."
+    NO_TOKEN_PROVIDED = "Warning: No token provided (-t option) and variable $CHANGELOG_GITHUB_TOKEN was not found. " \
+    "This script can make only 50 requests to GitHub API per hour without token!"
+
+    def initialize(options = {})
+      @options      = options || {}
+      @user         = @options[:user]
+      @project      = @options[:project]
+      # Only issues updated at or after this time are returned. This is a timestamp in ISO 8601 format: YYYY-MM-DDTHH:MM:SSZ.
+      @since        = @options[:since] # eg. Time.parse("2016-01-01 10:00:00").iso8601
+      @github_token = fetch_github_token
+
+      @request_options               = { :per_page => PER_PAGE_NUMBER }
+      @github_options                = {}
+      @github_options[:access_token] = @github_token unless @github_token.nil?
+      @github_options[:api_endpoint] = @options[:github_endpoint] unless @options[:github_endpoint].nil?
+
+      client_type = @options[:github_endpoint].nil? ? Octokit::Client : Octokit::EnterpriseAdminClient
+      @client     = client_type.new(@github_options)
+    end
+
+    # Returns GitHub token. First try to use variable, provided by --token option,
+    # otherwise try to fetch it from CHANGELOG_GITHUB_TOKEN env variable.
+    #
+    # @return [String]
+    def fetch_github_token
+      env_var = @options[:token] ? @options[:token] : (ENV.fetch CHANGELOG_GITHUB_TOKEN, nil)
+
+      Helper.log.warn NO_TOKEN_PROVIDED.yellow unless env_var
+
+      env_var
+    end
+
+    # Fetch all tags from repo
+    #
+    # @return [Array] array of tags
+    def get_all_tags
+      print "Fetching tags...\r" if @options[:verbose]
+
+      check_github_response { github_fetch_tags }
+    end
+
+    # This is wrapper with rescue block
+    #
+    # @return [Object] returns exactly the same, what you put in the block, but wrap it with begin-rescue block
+    def check_github_response
+      begin
+        value = yield
+      rescue Github::Error::Unauthorized => e
+        Helper.log.error e.body.red
+        abort "Error: wrong GitHub token"
+      rescue Github::Error::Forbidden => e
+        Helper.log.warn e.body.red
+        Helper.log.warn GH_RATE_LIMIT_EXCEEDED_MSG.yellow
+      end
+      value
+    end
+
+    # @return [String] helper to return Github "user/project"
+    def user_project
+      "#{@options[:user]}/#{@options[:project]}"
+    end
+
+    # Parses a URI and returns a hash of all GET variables
+    #
+    # @param [String] uri eg. https://api.github.com/repositories/43914960/tags?page=37&foo=1
+    # @return [Hash] of all GET variables. eg. { 'page' => 37, 'foo' => 1 }
+    def parse_url_for_vars(uri)
+      URI(uri).query.split("&").inject({}) do |params, get_var|
+        k,v = get_var.split("=")
+        params[k] = v
+        params
+      end
+    end
+
+    # Returns the number of pages for a API call
+    #
+    # @return [Integer] number of pages for this API call in total
+    def calculate_pages(client, method, request_options)
+      # Makes the first API call so that we can call last_response
+      client.send(method, user_project, @request_options.merge(request_options))
+      last_response = client.last_response
+
+      if last_pg = last_response.rels[:last]
+        parse_url_for_vars(last_pg.href)['page'].to_i
+      else
+        1
+      end
+    end
+
+    # Iterates through all pages until there are no more :next pages to follow
+    # yields the result per page
+    #
+    # @param [Octokit::Client] client
+    # @param [String] method (eg. 'tags')
+    # @return [Integer] total number of pages
+    def iterate_pages(client, method, *args, &block)
+      if args.size == 1 && args.first.is_a?(Hash)
+        request_options = args.delete_at(0)
+      elsif args.size > 1 && args.last.is_a?(Hash)
+        request_options = args.delete_at(args.length - 1)
+      end
+
+      args.push(@request_options.merge(request_options))
+      # args.push({}.merge(request_options))
+
+      pages = 1
+      client.send(method, user_project, *args)
+      # client.send(method, 'retentionscience/rsapi', *args)
+      last_response = client.last_response
+
+      yield last_response.data
+
+      while !(next_one = last_response.rels[:next]).nil?
+        pages +=1
+
+        last_response = next_one.get
+        yield last_response.data
+      end
+
+      pages
+    end
+
+
+    # Fill input array with tags
+    #
+    # @return [Array] array of tags in repo
+    def github_fetch_tags
+      tags        = []
+      page_i      = 0
+      count_pages = calculate_pages(@client, 'tags', {})
+
+      iterate_pages(@client, 'tags', {}) do |new_tags|
+        page_i += PER_PAGE_NUMBER
+        print_in_same_line("Fetching tags... #{page_i}/#{count_pages * PER_PAGE_NUMBER}")
+        tags.concat(new_tags)
+      end
+      print_empty_line
+
+      if tags.count == 0
+        Helper.log.warn "Warning: Can't find any tags in repo.\
+Make sure, that you push tags to remote repo via 'git push --tags'".yellow
+      else
+        Helper.log.info "Found #{tags.count} tags"
+      end
+      tags
+    end
+
+    # This method fetch all closed issues and separate them to pull requests and pure issues
+    # (pull request is kind of issue in term of GitHub)
+    #
+    # @return [Tuple] with (issues, pull-requests)
+    def fetch_closed_issues_and_pr
+      print "Fetching closed issues...\r" if @options[:verbose]
+      issues = []
+      options = {
+        :state  => "closed",
+        :filter => "all",
+        :labels => nil,
+        :since  => @since,
+      }
+
+      begin
+        page_i      = 0
+        count_pages = calculate_pages(@client, 'issues', options)
+
+        iterate_pages(@client, 'issues', options) do |new_issues|
+          page_i += PER_PAGE_NUMBER
+          print_in_same_line("Fetching issues... #{page_i}/#{count_pages * PER_PAGE_NUMBER}")
+          issues.concat(new_issues)
+          break if @options[:max_issues] && issues.length >= @options[:max_issues]
+        end
+        print_empty_line
+        Helper.log.info "Received issues: #{issues.count}"
+
+      rescue
+        Helper.log.warn GH_RATE_LIMIT_EXCEEDED_MSG.yellow
+      end
+
+      # separate arrays of issues and pull requests:
+      issues.partition do |x|
+        x[:pull_request].nil?
+      end
+    end
+
+    # Fetch all pull requests. We need them to detect :merged_at parameter
+    #
+    # @return [Array] all pull requests
+    def fetch_closed_pull_requests
+      pull_requests = []
+      options = { :state => 'closed' }
+
+      if !@options[:release_branch].nil?
+        options[:base] = @options[:release_branch]
+      end
+
+      begin
+        page_i = 0
+        count_pages = calculate_pages(@client, 'pull_requests', options)
+
+        iterate_pages(@client, 'pull_requests', options) do |new_pr|
+          page_i += PER_PAGE_NUMBER
+          log_string = "Fetching merged dates... #{page_i}/#{count_pages * PER_PAGE_NUMBER}"
+          print_in_same_line(log_string)
+          pull_requests.concat(new_pr)
+        end
+        print_empty_line
+      rescue
+        Helper.log.warn GH_RATE_LIMIT_EXCEEDED_MSG.yellow
+      end
+
+      Helper.log.info "Fetching merged dates: #{pull_requests.count}"
+      pull_requests
+    end
+
+    # Print specified line on the same string
+    #
+    # @param [String] log_string
+    def print_in_same_line(log_string)
+      print log_string + "\r"
+    end
+
+    # Print long line with spaces on same line to clear prev message
+    def print_empty_line
+      print_in_same_line("                                                                       ")
+    end
+
+    # Fetch event for all issues and add them to :events
+    #
+    # @param [Array] issues
+    # @return [Void]
+    def fetch_events_async(issues)
+      i       = 0
+      threads = []
+
+      issues.each_slice(MAX_THREAD_NUMBER) do |issues_slice|
+        issues_slice.each do |issue|
+          threads << Thread.new do
+            begin
+              issue[:events] = []
+              iterate_pages(@client, 'issue_events', issue['number'], {}) do |new_event|
+                issue[:events].concat(new_event)
+              end
+            rescue
+              Helper.log.warn GH_RATE_LIMIT_EXCEEDED_MSG.yellow
+            end
+            print_in_same_line("Fetching events for issues and PR: #{i + 1}/#{issues.count}")
+            i += 1
+          end
+        end
+        threads.each(&:join)
+        threads = []
+      end
+
+      # to clear line from prev print
+      print_empty_line
+
+      Helper.log.info "Fetching events for issues and PR: #{i}"
+    end
+
+    # Fetch tag time from repo
+    #
+    # @param [Hash] tag
+    # @return [Time] time of specified tag
+    def fetch_date_of_tag(tag)
+      begin
+        commit_data = @client.commit(user_project, tag['commit']['sha'])
+        commit_data[:commit][:committer][:date]
+      rescue
+        Helper.log.warn GH_RATE_LIMIT_EXCEEDED_MSG.yellow
+      end
+    end
+
+    # Fetch commit for specified event
+    #
+    # @return [Hash]
+    def fetch_commit(event)
+      @client.commit(user_project, event[:commit_id])
+    end
+  end
+end