diff --git a/.overcommit.yml b/.overcommit.yml
new file mode 100644
index 0000000..c5856dd
--- /dev/null
+++ b/.overcommit.yml
@@ -0,0 +1,12 @@
+PreCommit:
+  BundleCheck:
+    enabled: true
+
+  RuboCop:
+    enabled: true
+    required_executable: bundle
+    command: ["bundle", "exec", "standardrb"]
+    on_warn: fail
+
+  YamlSyntax:
+    enabled: true
diff --git a/.standard.yml b/.standard.yml
new file mode 100644
index 0000000..8aad730
--- /dev/null
+++ b/.standard.yml
@@ -0,0 +1,4 @@
+ignore:
+  - "**/*":
+      - Layout/SpaceInsideHashLiteralBraces
+      - Style/RescueStandardError
diff --git a/lib/miteru/attachement.rb b/lib/miteru/attachement.rb
index fadbebd..463b439 100644
--- a/lib/miteru/attachement.rb
+++ b/lib/miteru/attachement.rb
@@ -31,7 +31,7 @@ def vt_link
       {
         type: "button",
         text: "Lookup on VirusTotal",
-        url: _vt_link,
+        url: _vt_link
       }
     end
 
@@ -41,7 +41,7 @@ def urlscan_link
       {
         type: "button",
         text: "Lookup on urlscan.io",
-        url: _urlscan_link,
+        url: _urlscan_link
       }
     end
 
diff --git a/lib/miteru/error.rb b/lib/miteru/error.rb
index 22b29b6..558ac11 100644
--- a/lib/miteru/error.rb
+++ b/lib/miteru/error.rb
@@ -2,5 +2,6 @@
 
 module Miteru
   class HTTPResponseError < StandardError; end
+
   class DownloadError < StandardError; end
 end
diff --git a/lib/miteru/feeds.rb b/lib/miteru/feeds.rb
index 7ba8fba..1703963 100644
--- a/lib/miteru/feeds.rb
+++ b/lib/miteru/feeds.rb
@@ -9,7 +9,7 @@
 
 module Miteru
   class Feeds
-    IGNORE_EXTENSIONS = %w(.htm .html .php .asp .aspx .exe .txt).freeze
+    IGNORE_EXTENSIONS = %w[.htm .html .php .asp .aspx .exe .txt].freeze
 
     def initialize
       @feeds = [
@@ -48,7 +48,7 @@ def breakdown(url)
       segments = uri.path.split("/")
       return [base] if segments.length.zero?
 
-      urls = (0...segments.length).map { |idx| "#{base}#{segments[0..idx].join('/')}" }
+      urls = (0...segments.length).map { |idx| "#{base}#{segments[0..idx].join("/")}" }
 
       urls.reject do |breakdowned_url|
         # Reject a url which ends with specific extension names
diff --git a/lib/miteru/http_client.rb b/lib/miteru/http_client.rb
index bc98820..969f3fc 100644
--- a/lib/miteru/http_client.rb
+++ b/lib/miteru/http_client.rb
@@ -27,18 +27,18 @@ def head(url, options = {})
       options = options.merge default_options
 
       HTTP.follow
-          .timeout(3)
-          .headers(urlscan_url?(url) ? urlscan_headers : default_headers)
-          .head(url, options)
+        .timeout(3)
+        .headers(urlscan_url?(url) ? urlscan_headers : default_headers)
+        .head(url, options)
     end
 
     def get(url, options = {})
       options = options.merge default_options
 
       HTTP.follow
-          .timeout(write: 2, connect: 5, read: 10)
-          .headers(urlscan_url?(url) ? urlscan_headers : default_headers)
-          .get(url, options)
+        .timeout(write: 2, connect: 5, read: 10)
+        .headers(urlscan_url?(url) ? urlscan_headers : default_headers)
+        .get(url, options)
     end
 
     def post(url, options = {})
diff --git a/lib/miteru/kit.rb b/lib/miteru/kit.rb
index 2aee801..945ef6f 100644
--- a/lib/miteru/kit.rb
+++ b/lib/miteru/kit.rb
@@ -22,7 +22,7 @@ def initialize(url)
       @status = nil
     end
 
-    def valid?;
+    def valid?
       # make a HEAD request for the validation
       before_validation
 
diff --git a/miteru.gemspec b/miteru.gemspec
index 9521d28..426ff59 100644
--- a/miteru.gemspec
+++ b/miteru.gemspec
@@ -1,34 +1,36 @@
 # frozen_string_literal: true
 
-lib = File.expand_path('lib', __dir__)
+lib = File.expand_path("lib", __dir__)
 $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 require "miteru/version"
 
 Gem::Specification.new do |spec|
-  spec.name          = "miteru"
-  spec.version       = Miteru::VERSION
-  spec.authors       = ["Manabu Niseki"]
-  spec.email         = ["manabu.niseki@gmail.com"]
+  spec.name = "miteru"
+  spec.version = Miteru::VERSION
+  spec.authors = ["Manabu Niseki"]
+  spec.email = ["manabu.niseki@gmail.com"]
 
-  spec.summary       = "An experimental phishing kit detector"
-  spec.description   = "An experimental phishing kit detector"
-  spec.homepage      = "https://github.com/ninoseki/miteru"
-  spec.license       = "MIT"
+  spec.summary = "An experimental phishing kit detector"
+  spec.description = "An experimental phishing kit detector"
+  spec.homepage = "https://github.com/ninoseki/miteru"
+  spec.license = "MIT"
 
   # Specify which files should be added to the gem when it is released.
   # The `git ls-files -z` loads the files in the RubyGem that have been added into git.
   spec.files = Dir.chdir(File.expand_path(__dir__)) do
     `git ls-files -z`.split("\x0").reject { |f| f.match(%r{^(test|spec|features)/}) }
   end
-  spec.bindir        = "exe"
-  spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
+  spec.bindir = "exe"
+  spec.executables = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
 
   spec.add_development_dependency "bundler", "~> 2.2"
   spec.add_development_dependency "coveralls_reborn", "~> 0.22"
   spec.add_development_dependency "glint", "~> 0.1"
+  spec.add_development_dependency "overcommit", "~> 0.58"
   spec.add_development_dependency "rake", "~> 13.0"
   spec.add_development_dependency "rspec", "~> 3.10"
+  spec.add_development_dependency "standard", "~> 1.3"
   spec.add_development_dependency "vcr", "~> 6.0"
   spec.add_development_dependency "webmock", "~> 3.14"
   spec.add_development_dependency "webrick", "~> 1.7.0"
diff --git a/spec/cli_spec.rb b/spec/cli_spec.rb
index 17b7e1b..2d57cb7 100644
--- a/spec/cli_spec.rb
+++ b/spec/cli_spec.rb
@@ -9,7 +9,7 @@
     end
 
     it "does not raise any error" do
-      capture(:stdout) { described_class.start %w(execute) }
+      capture(:stdout) { described_class.start %w[execute] }
     end
   end
 
diff --git a/spec/downloader_spec.rb b/spec/downloader_spec.rb
index e9fc2ae..ed1ec7b 100644
--- a/spec/downloader_spec.rb
+++ b/spec/downloader_spec.rb
@@ -44,7 +44,7 @@
       it "removes duplicated files" do
         kits = [
           Miteru::Kit.new(url + "/test.zip"),
-          Miteru::Kit.new( url + "/test.zip")
+          Miteru::Kit.new(url + "/test.zip")
         ]
         expect(Dir.glob("#{base_dir}/*.zip").empty?).to be(true)
 
diff --git a/spec/support/helpers/helpers.rb b/spec/support/helpers/helpers.rb
index a3db4b9..6355631 100644
--- a/spec/support/helpers/helpers.rb
+++ b/spec/support/helpers/helpers.rb
@@ -1,5 +1,6 @@
 # frozen_string_literal: true
 
+# rubocop:disable Style/EvalWithLocation, Security/Eval
 module Spec
   module Support
     module Helpers
@@ -17,3 +18,4 @@ def capture(stream)
     end
   end
 end
+# rubocop:enable Style/EvalWithLocation, Security/Eval
diff --git a/spec/support/shared_contexts/http_server_context.rb b/spec/support/shared_contexts/http_server_context.rb
index 27529b7..fbd0209 100644
--- a/spec/support/shared_contexts/http_server_context.rb
+++ b/spec/support/shared_contexts/http_server_context.rb
@@ -22,7 +22,7 @@ def server
 
       res.status = status
       res.content_length = body.size
-      res.content_type = 'text/plain'
+      res.content_type = "text/plain"
       res.body = body
     end
 
@@ -32,7 +32,7 @@ def server
 
       res.status = 200
       res.content_length = body.size
-      res.content_type = 'application/zip'
+      res.content_type = "application/zip"
       res.body = body
     end
 
@@ -42,7 +42,7 @@ def server
 
       res.status = 200
       res.content_length = body.size
-      res.content_type = 'application/gzip'
+      res.content_type = "application/gzip"
       res.body = body
     end
 
@@ -53,7 +53,7 @@ def server
 
       res.status = status
       res.content_length = body.size
-      res.content_type = 'text/plain'
+      res.content_type = "text/plain"
       res.body = body
     end