diff --git a/.rubocop.yml b/.rubocop.yml
new file mode 100644
index 0000000..62d9f2f
--- /dev/null
+++ b/.rubocop.yml
@@ -0,0 +1,26 @@
+##
+# Plugins
+require:
+  - standard
+
+##
+# Defaults: standard-rb
+inherit_gem:
+  standard: config/base.yml
+
+AllCops:
+  TargetRubyVersion: 3.1
+
+##
+# Enabled cops
+Style/FrozenStringLiteralComment:
+   Enabled: true
+
+##
+# Disabled cops
+Layout/MultilineMethodCallIndentation:
+  Enabled: false
+Layout/ArgumentAlignment:
+  Enabled: false
+Style/LambdaCall:
+  Enabled: false
diff --git a/bin/json/pull-arabic b/bin/json/pull-arabic
index 6ab5c6e..3ea8d90 100755
--- a/bin/json/pull-arabic
+++ b/bin/json/pull-arabic
@@ -1,11 +1,16 @@
 #!/usr/bin/env ruby
-#
+# frozen_string_literal: true
+
+##
 # This script requests each verse, in each chapter
 # of The Qur'an - in the Arabic language. The content
 # is requested from the https://sacred-texts.com website.
 #
 # Each chapter is then saved in a JSON file, for example:
 # "src/json/ar/1.json", "src/json/ar/2.json", etc.
+
+##
+# Set process name
 $0 = "pull-arabic"
 
 ##
@@ -33,7 +38,7 @@ line = IO::Line.new($stdout)
 find_content = ->(res) do
   html = Nokogiri::HTML(res.body)
   html.css("table tr td p[align=RIGHT]").map do
-    _1.text.gsub(/[0-9]+/, '')
+    _1.text.gsub(/[0-9]+/, "")
       .delete("\u200F")
       .delete("\u200E")
       .strip
diff --git a/bin/json/pull-english b/bin/json/pull-english
index 9fa1c05..93594b0 100755
--- a/bin/json/pull-english
+++ b/bin/json/pull-english
@@ -1,5 +1,7 @@
 #!/usr/bin/env ruby
-#
+# frozen_string_literal: true
+
+##
 # This script requests each verse, in each chapter
 # of The Qur'an - in the English language. The content
 # is requested from the https://quran.com website.
diff --git a/bin/json/pull-farsi b/bin/json/pull-farsi
index e483318..84fa98b 100755
--- a/bin/json/pull-farsi
+++ b/bin/json/pull-farsi
@@ -1,4 +1,5 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
 
 ##
 # This script requests each verse, in each chapter
@@ -104,9 +105,7 @@ end
     sleep 0.1
   end
   File.write(final_dest, JSON.pretty_generate(rows))
-  print Paint["OK: ", :green, :bold], final_dest.sub(ENV['HOME'], ''), "\n"
+  print Paint["OK: ", :green, :bold], final_dest.sub(ENV["HOME"], ""), "\n"
   sleep cool_off
   print Paint["Chill for #{cool_off} seconds", :blue, :bold], "\n", "\n"
 end
-
-
diff --git a/bin/json/pull-portuguese b/bin/json/pull-portuguese
index bdff71b..7ca7c58 100755
--- a/bin/json/pull-portuguese
+++ b/bin/json/pull-portuguese
@@ -1,4 +1,5 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
 
 ##
 # This script requests each verse, in each chapter
@@ -80,7 +81,7 @@ end
 def extract_verse!(res, remove_suratu)
   doc = Nokogiri::HTML(res.body)
   verse = doc.css(".ayah .translate").first
-  (remove_suratu ? verse.text.sub(/^Suratu [\w\-.]+/, '') : verse.text).strip
+  (remove_suratu ? verse.text.sub(/^Suratu [\w\-.]+/, "") : verse.text).strip
 end
 
 ##
@@ -103,9 +104,7 @@ end
     end
   end
   File.write(final_dest, JSON.pretty_generate(rows))
-  print Paint["OK: ", :green, :bold], final_dest.sub(ENV['HOME'], ''), "\n"
+  print Paint["OK: ", :green, :bold], final_dest.sub(ENV["HOME"], ""), "\n"
   sleep cool_off
   print Paint["Chill for #{cool_off} seconds", :blue, :bold], "\n", "\n"
 end
-
-
diff --git a/bin/sql/create-sql-seed-file b/bin/sql/create-sql-seed-file
index d7a9d8e..9d7931f 100755
--- a/bin/sql/create-sql-seed-file
+++ b/bin/sql/create-sql-seed-file
@@ -1,10 +1,12 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
 
 require "json"
 require "erb"
 
 module SQLUtils
   module_function
+
   def escape(str)
     char = "'"
     char + str.gsub(char, char * 2) + char
@@ -20,8 +22,8 @@ class Language
 
   def chapters
     Dir.glob(File.join(
-      __dir__,  "..",  "src",
-      "json",  @locale,  "*.json"
+      __dir__, "..", "src",
+      "json", @locale, "*.json"
     )).map { Chapter.new(_1) }.sort_by(&:number)
   end
 end
@@ -32,7 +34,7 @@ class Chapter
   end
 
   def number
-    File.basename(@path, '.json').to_i
+    File.basename(@path, ".json").to_i
   end
 
   def verses
@@ -49,10 +51,9 @@ class Verse
   end
 end
 
-
-base_dir  = File.join(__dir__, "..", "src", "sql")
-template  = File.read File.join(base_dir, "seed.sql.erb")
-languages = %w(ar en pt fa).map { Language.new(_1) }
+base_dir = File.join(__dir__, "..", "src", "sql")
+template = File.read File.join(base_dir, "seed.sql.erb")
+languages = %w[ar en pt fa].map { Language.new(_1) }
 result = ERB.new(template)
             .result_with_hash(chapter_id: 1, languages:)
             .each_line.map(&:strip)
diff --git a/binlib/io/line.rb b/binlib/io/line.rb
index 50fcb9d..31ee0aa 100644
--- a/binlib/io/line.rb
+++ b/binlib/io/line.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 class IO::Line
   require "io/console"
   attr_reader :io
diff --git a/gem.deps.rb b/gem.deps.rb
index ee02352..1a1040b 100644
--- a/gem.deps.rb
+++ b/gem.deps.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 gem "nokogiri", "~> 1.13"
 gem "paint", "~> 2.2"
 gem "json", "~> 2.6"