diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index d3e56e6..796ba9d 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -6,18 +6,15 @@ jobs:
     env:
       RAILS_ENV: test
       DATABASE_URL: postgres://test:password@127.0.0.1:5432/grape_on_rails_test
-      BUNDLE_GEMFILE: ${{ github.workspace }}/gemfiles/${{ matrix.gemfile.file }}.gemfile
+      BUNDLE_GEMFILE: ${{ github.workspace }}/gemfiles/${{ matrix.entry.gemfile }}.gemfile
     strategy:
       fail-fast: false
       matrix:
-        gemfile:
-          - { ruby: '2.7', file: rails_6 }
-          - { ruby: '3.0', file: rails_6_1 }
-          - { ruby: '3.1', file: rails_7 }
-          - { ruby: '3.2', file: rails_7 }
-          - { ruby: '3.3', file: rails_7 }
-          - { ruby: '3.4', file: rails_7 }
-#          - { ruby: '3.2' ,file: rails_edge }
+        entry:
+          - { ruby: '3.0', gemfile: rails_6_1 }
+          - { ruby: '3.2', gemfile: rails_7 }
+          - { ruby: '3.4', gemfile: rails_8 }
+#          - { ruby: '3.2', gemfile: rails_edge }
     steps:
       - uses: actions/checkout@v3
       - name: Set up Ruby
@@ -36,7 +33,7 @@ jobs:
         run: cp config/database.gha.yml config/database.yml
       - uses: harmon758/postgresql-action@v1
         with:
-          postgresql version: "14"
+          postgresql version: "17"
           postgresql db: grape_on_rails_test
           postgresql user: test
           postgresql password: password
diff --git a/.rspec b/.rspec
index 412e568..be4750a 100644
--- a/.rspec
+++ b/.rspec
@@ -1,3 +1,4 @@
+--require spec_helper
 --color
 --format=documentation
 
diff --git a/.rubocop.yml b/.rubocop.yml
index ed78494..e9d9409 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -13,7 +13,7 @@ Style/FrozenStringLiteralComment:
 Layout/LineLength:
   Enabled: false
   
-require:
+plugins:
   - rubocop-capybara
   - rubocop-rails
   - rubocop-rspec_rails
diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index 521a5cd..86d30a2 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -1,6 +1,6 @@
 # This configuration was generated by
 # `rubocop --auto-gen-config`
-# on 2025-02-20 15:23:50 UTC using RuboCop version 1.62.1.
+# on 2025-09-26 12:55:58 UTC using RuboCop version 1.81.0.
 # The point is for the user to remove these configuration records
 # one by one as the offenses are removed from the code base.
 # Note that changes in the inspected code, or installation of new
@@ -14,7 +14,6 @@ Lint/EmptyBlock:
 
 # Offense count: 1
 # This cop supports unsafe autocorrection (--autocorrect-all).
-# Configuration parameters: AutoCorrect.
 RSpec/EmptyExampleGroup:
   Exclude:
     - 'spec/helpers/welcome_helper_spec.rb'
@@ -34,8 +33,7 @@ RSpec/RepeatedExample:
     - 'spec/api/headers_spec.rb'
 
 # Offense count: 5
-# Configuration parameters: Include, CustomTransform, IgnoreMethods, IgnoreMetadata.
-# Include: **/*_spec.rb
+# Configuration parameters: CustomTransform, IgnoreMethods, IgnoreMetadata.
 RSpec/SpecFilePathFormat:
   Exclude:
     - 'spec/api/headers_spec.rb'
diff --git a/.ruby-version b/.ruby-version
deleted file mode 100644
index ef538c2..0000000
--- a/.ruby-version
+++ /dev/null
@@ -1 +0,0 @@
-3.1.2
diff --git a/Appraisals b/Appraisals
index ca6d0d2..07b792e 100644
--- a/Appraisals
+++ b/Appraisals
@@ -1,9 +1,5 @@
 # frozen_string_literal: true
 
-appraise 'rails-6' do
-  gem 'rails', '~> 6.0'
-end
-
 appraise 'rails-6-1' do
   gem 'rails', '~> 6.1'
 end
@@ -12,6 +8,10 @@ appraise 'rails-7' do
   gem 'rails', '~> 7.0'
 end
 
+appraise 'rails-8' do
+  gem 'rails', '~> 8.0'
+end
+
 appraise 'rails-edge' do
   gem 'rails', github: 'rails/rails'
 end
diff --git a/Gemfile b/Gemfile
index 044f69a..a491aac 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,17 +1,16 @@
 source 'https://rubygems.org'
 git_source(:github) { |repo| "https://github.com/#{repo}.git" }
 
-# https://stackoverflow.com/questions/79360526/uninitialized-constant-activesupportloggerthreadsafelevellogger-nameerror
-gem 'concurrent-ruby', '1.3.4'
+gem 'concurrent-ruby'
 
 # Bundle edge Rails instead: gem "rails", github: "rails/rails", branch: "main"
-gem 'rails', '~> 7.0.8'
+gem 'rails', '~> 8.0.3'
 
 # The original asset pipeline for Rails [https://github.com/rails/sprockets-rails]
 gem 'sprockets-rails'
 
 # Use postgresql as the database for Active Record
-gem 'pg', '~> 1.1'
+gem 'pg'
 
 # Use the Puma web server [https://github.com/puma/puma]
 gem 'puma'
@@ -49,7 +48,7 @@ gem 'bootsnap', require: false
 # Use Active Storage variants [https://guides.rubyonrails.org/active_storage_overview.html#transforming-images]
 # gem "image_processing", "~> 1.2"
 
-gem 'grape', '~> 2.1'
+gem 'grape', '~> 2.4'
 gem 'grape-swagger'
 
 group :development, :test do
@@ -73,13 +72,14 @@ end
 group :test do
   # Use system testing [https://guides.rubyonrails.org/testing.html#system-testing]
   gem 'capybara'
+  gem 'mutex_m'
   gem 'rspec'
   gem 'rspec-rails'
-  gem 'rubocop', '1.62.1'
+  gem 'rubocop'
   gem 'rubocop-capybara'
   gem 'rubocop-rails'
   gem 'rubocop-rake'
   gem 'rubocop-rspec'
   gem 'rubocop-rspec_rails'
-  gem 'selenium-webdriver', '4.20'
+  gem 'selenium-webdriver'
 end
diff --git a/Gemfile.lock b/Gemfile.lock
index 15d58ed..e5290a4 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,82 +1,89 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    actioncable (7.0.8.7)
-      actionpack (= 7.0.8.7)
-      activesupport (= 7.0.8.7)
+    actioncable (8.0.3)
+      actionpack (= 8.0.3)
+      activesupport (= 8.0.3)
       nio4r (~> 2.0)
       websocket-driver (>= 0.6.1)
-    actionmailbox (7.0.8.7)
-      actionpack (= 7.0.8.7)
-      activejob (= 7.0.8.7)
-      activerecord (= 7.0.8.7)
-      activestorage (= 7.0.8.7)
-      activesupport (= 7.0.8.7)
-      mail (>= 2.7.1)
-      net-imap
-      net-pop
-      net-smtp
-    actionmailer (7.0.8.7)
-      actionpack (= 7.0.8.7)
-      actionview (= 7.0.8.7)
-      activejob (= 7.0.8.7)
-      activesupport (= 7.0.8.7)
-      mail (~> 2.5, >= 2.5.4)
-      net-imap
-      net-pop
-      net-smtp
-      rails-dom-testing (~> 2.0)
-    actionpack (7.0.8.7)
-      actionview (= 7.0.8.7)
-      activesupport (= 7.0.8.7)
-      rack (~> 2.0, >= 2.2.4)
+      zeitwerk (~> 2.6)
+    actionmailbox (8.0.3)
+      actionpack (= 8.0.3)
+      activejob (= 8.0.3)
+      activerecord (= 8.0.3)
+      activestorage (= 8.0.3)
+      activesupport (= 8.0.3)
+      mail (>= 2.8.0)
+    actionmailer (8.0.3)
+      actionpack (= 8.0.3)
+      actionview (= 8.0.3)
+      activejob (= 8.0.3)
+      activesupport (= 8.0.3)
+      mail (>= 2.8.0)
+      rails-dom-testing (~> 2.2)
+    actionpack (8.0.3)
+      actionview (= 8.0.3)
+      activesupport (= 8.0.3)
+      nokogiri (>= 1.8.5)
+      rack (>= 2.2.4)
+      rack-session (>= 1.0.1)
       rack-test (>= 0.6.3)
-      rails-dom-testing (~> 2.0)
-      rails-html-sanitizer (~> 1.0, >= 1.2.0)
-    actiontext (7.0.8.7)
-      actionpack (= 7.0.8.7)
-      activerecord (= 7.0.8.7)
-      activestorage (= 7.0.8.7)
-      activesupport (= 7.0.8.7)
+      rails-dom-testing (~> 2.2)
+      rails-html-sanitizer (~> 1.6)
+      useragent (~> 0.16)
+    actiontext (8.0.3)
+      actionpack (= 8.0.3)
+      activerecord (= 8.0.3)
+      activestorage (= 8.0.3)
+      activesupport (= 8.0.3)
       globalid (>= 0.6.0)
       nokogiri (>= 1.8.5)
-    actionview (7.0.8.7)
-      activesupport (= 7.0.8.7)
+    actionview (8.0.3)
+      activesupport (= 8.0.3)
       builder (~> 3.1)
-      erubi (~> 1.4)
-      rails-dom-testing (~> 2.0)
-      rails-html-sanitizer (~> 1.1, >= 1.2.0)
-    activejob (7.0.8.7)
-      activesupport (= 7.0.8.7)
+      erubi (~> 1.11)
+      rails-dom-testing (~> 2.2)
+      rails-html-sanitizer (~> 1.6)
+    activejob (8.0.3)
+      activesupport (= 8.0.3)
       globalid (>= 0.3.6)
-    activemodel (7.0.8.7)
-      activesupport (= 7.0.8.7)
-    activerecord (7.0.8.7)
-      activemodel (= 7.0.8.7)
-      activesupport (= 7.0.8.7)
-    activestorage (7.0.8.7)
-      actionpack (= 7.0.8.7)
-      activejob (= 7.0.8.7)
-      activerecord (= 7.0.8.7)
-      activesupport (= 7.0.8.7)
+    activemodel (8.0.3)
+      activesupport (= 8.0.3)
+    activerecord (8.0.3)
+      activemodel (= 8.0.3)
+      activesupport (= 8.0.3)
+      timeout (>= 0.4.0)
+    activestorage (8.0.3)
+      actionpack (= 8.0.3)
+      activejob (= 8.0.3)
+      activerecord (= 8.0.3)
+      activesupport (= 8.0.3)
       marcel (~> 1.0)
-      mini_mime (>= 1.1.0)
-    activesupport (7.0.8.7)
-      concurrent-ruby (~> 1.0, >= 1.0.2)
+    activesupport (8.0.3)
+      base64
+      benchmark (>= 0.3)
+      bigdecimal
+      concurrent-ruby (~> 1.0, >= 1.3.1)
+      connection_pool (>= 2.2.5)
+      drb
       i18n (>= 1.6, < 2)
+      logger (>= 1.4.2)
       minitest (>= 5.1)
-      tzinfo (~> 2.0)
+      securerandom (>= 0.3)
+      tzinfo (~> 2.0, >= 2.0.5)
+      uri (>= 0.13.1)
     addressable (2.8.7)
       public_suffix (>= 2.0.2, < 7.0)
     appraisal (2.5.0)
       bundler
       rake
       thor (>= 0.14.0)
-    ast (2.4.2)
-    base64 (0.2.0)
-    bigdecimal (3.1.9)
+    ast (2.4.3)
+    base64 (0.3.0)
+    benchmark (0.4.1)
+    bigdecimal (3.2.3)
     bindex (0.8.1)
-    bootsnap (1.18.4)
+    bootsnap (1.18.6)
       msgpack (~> 1.2)
     builder (3.3.0)
     capybara (3.40.0)
@@ -88,13 +95,15 @@ GEM
       rack-test (>= 0.6.3)
       regexp_parser (>= 1.5, < 3.0)
       xpath (~> 3.2)
-    concurrent-ruby (1.3.4)
+    concurrent-ruby (1.3.5)
+    connection_pool (2.5.4)
     crass (1.0.6)
     date (3.4.1)
-    debug (1.10.0)
+    debug (1.11.0)
       irb (~> 1.10)
       reline (>= 0.3.8)
-    diff-lcs (1.6.0)
+    diff-lcs (1.6.2)
+    drb (2.2.3)
     dry-core (1.1.0)
       concurrent-ruby (~> 1.0)
       logger
@@ -105,18 +114,19 @@ GEM
       concurrent-ruby (~> 1.0)
       dry-core (~> 1.1)
       zeitwerk (~> 2.6)
-    dry-types (1.8.2)
+    dry-types (1.8.3)
       bigdecimal (~> 3.0)
       concurrent-ruby (~> 1.0)
       dry-core (~> 1.0)
       dry-inflector (~> 1.0)
       dry-logic (~> 1.4)
       zeitwerk (~> 2.6)
+    erb (5.0.2)
     erubi (1.13.1)
-    globalid (1.2.1)
+    globalid (1.3.0)
+      activesupport (>= 6.1)
+    grape (2.4.0)
       activesupport (>= 6.1)
-    grape (2.3.0)
-      activesupport (>= 6)
       dry-types (>= 1.1)
       mustermann-grape (~> 1.1.0)
       rack (>= 2)
@@ -126,22 +136,23 @@ GEM
       rack-test (~> 2)
     i18n (1.14.7)
       concurrent-ruby (~> 1.0)
-    importmap-rails (2.1.0)
+    importmap-rails (2.2.2)
       actionpack (>= 6.0.0)
       activesupport (>= 6.0.0)
       railties (>= 6.0.0)
-    io-console (0.8.0)
-    irb (1.15.1)
+    io-console (0.8.1)
+    irb (1.15.2)
       pp (>= 0.6.0)
       rdoc (>= 4.0.0)
       reline (>= 0.4.2)
-    jbuilder (2.13.0)
-      actionview (>= 5.0.0)
-      activesupport (>= 5.0.0)
-    json (2.10.1)
-    language_server-protocol (3.17.0.4)
-    logger (1.6.6)
-    loofah (2.24.0)
+    jbuilder (2.14.1)
+      actionview (>= 7.0.0)
+      activesupport (>= 7.0.0)
+    json (2.15.0)
+    language_server-protocol (3.17.0.5)
+    lint_roller (1.1.0)
+    logger (1.7.0)
+    loofah (2.24.1)
       crass (~> 1.0.2)
       nokogiri (>= 1.12.0)
     mail (2.8.1)
@@ -149,18 +160,18 @@ GEM
       net-imap
       net-pop
       net-smtp
-    marcel (1.0.4)
-    matrix (0.4.2)
-    method_source (1.1.0)
+    marcel (1.1.0)
+    matrix (0.4.3)
     mini_mime (1.1.5)
     mini_portile2 (2.8.9)
-    minitest (5.25.4)
+    minitest (5.25.5)
     msgpack (1.8.0)
-    mustermann (3.0.3)
+    mustermann (3.0.4)
       ruby2_keywords (~> 0.0.1)
     mustermann-grape (1.1.0)
       mustermann (>= 1.0.0)
-    net-imap (0.5.7)
+    mutex_m (0.3.0)
+    net-imap (0.5.10)
       date
       net-protocol
     net-pop (0.1.2)
@@ -170,121 +181,139 @@ GEM
     net-smtp (0.5.1)
       net-protocol
     nio4r (2.7.4)
-    nokogiri (1.18.9)
+    nokogiri (1.18.10)
       mini_portile2 (~> 2.8.2)
       racc (~> 1.4)
-    parallel (1.26.3)
-    parser (3.3.7.1)
+    parallel (1.27.0)
+    parser (3.3.9.0)
       ast (~> 2.4.1)
       racc
-    pg (1.5.9)
+    pg (1.6.2)
     pp (0.6.2)
       prettyprint
     prettyprint (0.2.0)
-    psych (5.2.3)
+    prism (1.5.1)
+    psych (5.2.6)
       date
       stringio
-    public_suffix (6.0.1)
-    puma (6.6.0)
+    public_suffix (6.0.2)
+    puma (7.0.4)
       nio4r (~> 2.0)
     racc (1.8.1)
-    rack (2.2.18)
+    rack (3.2.1)
+    rack-session (2.1.1)
+      base64 (>= 0.1.0)
+      rack (>= 3.0.0)
     rack-test (2.2.0)
       rack (>= 1.3)
-    rails (7.0.8.7)
-      actioncable (= 7.0.8.7)
-      actionmailbox (= 7.0.8.7)
-      actionmailer (= 7.0.8.7)
-      actionpack (= 7.0.8.7)
-      actiontext (= 7.0.8.7)
-      actionview (= 7.0.8.7)
-      activejob (= 7.0.8.7)
-      activemodel (= 7.0.8.7)
-      activerecord (= 7.0.8.7)
-      activestorage (= 7.0.8.7)
-      activesupport (= 7.0.8.7)
+    rackup (2.2.1)
+      rack (>= 3)
+    rails (8.0.3)
+      actioncable (= 8.0.3)
+      actionmailbox (= 8.0.3)
+      actionmailer (= 8.0.3)
+      actionpack (= 8.0.3)
+      actiontext (= 8.0.3)
+      actionview (= 8.0.3)
+      activejob (= 8.0.3)
+      activemodel (= 8.0.3)
+      activerecord (= 8.0.3)
+      activestorage (= 8.0.3)
+      activesupport (= 8.0.3)
       bundler (>= 1.15.0)
-      railties (= 7.0.8.7)
-    rails-dom-testing (2.2.0)
+      railties (= 8.0.3)
+    rails-dom-testing (2.3.0)
       activesupport (>= 5.0.0)
       minitest
       nokogiri (>= 1.6)
     rails-html-sanitizer (1.6.2)
       loofah (~> 2.21)
       nokogiri (>= 1.15.7, != 1.16.7, != 1.16.6, != 1.16.5, != 1.16.4, != 1.16.3, != 1.16.2, != 1.16.1, != 1.16.0.rc1, != 1.16.0)
-    railties (7.0.8.7)
-      actionpack (= 7.0.8.7)
-      activesupport (= 7.0.8.7)
-      method_source
+    railties (8.0.3)
+      actionpack (= 8.0.3)
+      activesupport (= 8.0.3)
+      irb (~> 1.13)
+      rackup (>= 1.0.0)
       rake (>= 12.2)
-      thor (~> 1.0)
-      zeitwerk (~> 2.5)
+      thor (~> 1.0, >= 1.2.2)
+      tsort (>= 0.2)
+      zeitwerk (~> 2.6)
     rainbow (3.1.1)
-    rake (13.2.1)
-    rdoc (6.12.0)
+    rake (13.3.0)
+    rdoc (6.14.2)
+      erb
       psych (>= 4.0.0)
-    regexp_parser (2.10.0)
-    reline (0.6.0)
+    regexp_parser (2.11.3)
+    reline (0.6.2)
       io-console (~> 0.5)
-    rexml (3.4.2)
-    rspec (3.13.0)
+    rexml (3.4.4)
+    rspec (3.13.1)
       rspec-core (~> 3.13.0)
       rspec-expectations (~> 3.13.0)
       rspec-mocks (~> 3.13.0)
-    rspec-core (3.13.3)
+    rspec-core (3.13.5)
       rspec-support (~> 3.13.0)
-    rspec-expectations (3.13.3)
+    rspec-expectations (3.13.5)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.13.0)
-    rspec-mocks (3.13.2)
+    rspec-mocks (3.13.5)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.13.0)
-    rspec-rails (7.1.1)
-      actionpack (>= 7.0)
-      activesupport (>= 7.0)
-      railties (>= 7.0)
+    rspec-rails (8.0.2)
+      actionpack (>= 7.2)
+      activesupport (>= 7.2)
+      railties (>= 7.2)
       rspec-core (~> 3.13)
       rspec-expectations (~> 3.13)
       rspec-mocks (~> 3.13)
       rspec-support (~> 3.13)
-    rspec-support (3.13.2)
-    rubocop (1.62.1)
+    rspec-support (3.13.6)
+    rubocop (1.81.0)
       json (~> 2.3)
-      language_server-protocol (>= 3.17.0)
+      language_server-protocol (~> 3.17.0.2)
+      lint_roller (~> 1.1.0)
       parallel (~> 1.10)
       parser (>= 3.3.0.2)
       rainbow (>= 2.2.2, < 4.0)
-      regexp_parser (>= 1.8, < 3.0)
-      rexml (>= 3.2.5, < 4.0)
-      rubocop-ast (>= 1.31.1, < 2.0)
+      regexp_parser (>= 2.9.3, < 3.0)
+      rubocop-ast (>= 1.47.1, < 2.0)
       ruby-progressbar (~> 1.7)
-      unicode-display_width (>= 2.4.0, < 3.0)
-    rubocop-ast (1.38.0)
-      parser (>= 3.3.1.0)
-    rubocop-capybara (2.21.0)
-      rubocop (~> 1.41)
-    rubocop-rails (2.29.1)
+      unicode-display_width (>= 2.4.0, < 4.0)
+    rubocop-ast (1.47.1)
+      parser (>= 3.3.7.2)
+      prism (~> 1.4)
+    rubocop-capybara (2.22.1)
+      lint_roller (~> 1.1)
+      rubocop (~> 1.72, >= 1.72.1)
+    rubocop-rails (2.33.3)
       activesupport (>= 4.2.0)
+      lint_roller (~> 1.1)
       rack (>= 1.1)
-      rubocop (>= 1.52.0, < 2.0)
-      rubocop-ast (>= 1.31.1, < 2.0)
-    rubocop-rake (0.6.0)
-      rubocop (~> 1.0)
-    rubocop-rspec (3.4.0)
-      rubocop (~> 1.61)
-    rubocop-rspec_rails (2.30.0)
-      rubocop (~> 1.61)
-      rubocop-rspec (~> 3, >= 3.0.1)
+      rubocop (>= 1.75.0, < 2.0)
+      rubocop-ast (>= 1.44.0, < 2.0)
+    rubocop-rake (0.7.1)
+      lint_roller (~> 1.1)
+      rubocop (>= 1.72.1)
+    rubocop-rspec (3.7.0)
+      lint_roller (~> 1.1)
+      rubocop (~> 1.72, >= 1.72.1)
+    rubocop-rspec_rails (2.31.0)
+      lint_roller (~> 1.1)
+      rubocop (~> 1.72, >= 1.72.1)
+      rubocop-rspec (~> 3.5)
     ruby-progressbar (1.13.0)
     ruby2_keywords (0.0.5)
-    rubyzip (2.4.1)
-    selenium-webdriver (4.20.0)
+    rubyzip (3.1.0)
+    securerandom (0.4.1)
+    selenium-webdriver (4.35.0)
       base64 (~> 0.2)
+      logger (~> 1.4)
       rexml (~> 3.2, >= 3.2.5)
-      rubyzip (>= 1.2.2, < 3.0)
+      rubyzip (>= 1.2.2, < 4.0)
       websocket (~> 1.0)
-    sprockets (4.2.1)
+    sprockets (4.2.2)
       concurrent-ruby (~> 1.0)
+      logger
       rack (>= 2.2.4, < 4)
     sprockets-rails (3.5.2)
       actionpack (>= 6.1)
@@ -292,28 +321,33 @@ GEM
       sprockets (>= 3.0.0)
     stimulus-rails (1.3.4)
       railties (>= 6.0.0)
-    stringio (3.1.4)
+    stringio (3.1.7)
     thor (1.4.0)
     timeout (0.4.3)
-    turbo-rails (2.0.11)
-      actionpack (>= 6.0.0)
-      railties (>= 6.0.0)
+    tsort (0.2.0)
+    turbo-rails (2.0.16)
+      actionpack (>= 7.1.0)
+      railties (>= 7.1.0)
     tzinfo (2.0.6)
       concurrent-ruby (~> 1.0)
-    unicode-display_width (2.6.0)
+    unicode-display_width (3.2.0)
+      unicode-emoji (~> 4.1)
+    unicode-emoji (4.1.0)
+    uri (1.0.3)
+    useragent (0.16.11)
     web-console (4.2.1)
       actionview (>= 6.0.0)
       activemodel (>= 6.0.0)
       bindex (>= 0.4.0)
       railties (>= 6.0.0)
     websocket (1.2.11)
-    websocket-driver (0.7.7)
+    websocket-driver (0.8.0)
       base64
       websocket-extensions (>= 0.1.0)
     websocket-extensions (0.1.5)
     xpath (3.2.0)
       nokogiri (~> 1.8)
-    zeitwerk (2.7.2)
+    zeitwerk (2.7.3)
 
 PLATFORMS
   ruby
@@ -322,24 +356,25 @@ DEPENDENCIES
   appraisal
   bootsnap
   capybara
-  concurrent-ruby (= 1.3.4)
+  concurrent-ruby
   debug
-  grape (~> 2.1)
+  grape (~> 2.4)
   grape-swagger
   importmap-rails
   jbuilder
-  pg (~> 1.1)
+  mutex_m
+  pg
   puma
-  rails (~> 7.0.8)
+  rails (~> 8.0.3)
   rspec
   rspec-rails
-  rubocop (= 1.62.1)
+  rubocop
   rubocop-capybara
   rubocop-rails
   rubocop-rake
   rubocop-rspec
   rubocop-rspec_rails
-  selenium-webdriver (= 4.20)
+  selenium-webdriver
   sprockets-rails
   stimulus-rails
   turbo-rails
diff --git a/README.md b/README.md
index 9a1c1b1..59486be 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,6 @@
 
 [![Test](https://github.com/ruby-grape/grape-on-rails/actions/workflows/test.yml/badge.svg?branch=master)](https://github.com/ruby-grape/grape-on-rails/actions/workflows/test.yml)
 [![Rubocop](https://github.com/ruby-grape/grape-on-rails/actions/workflows/test.yml/badge.svg?branch=master)](https://github.com/ruby-grape/grape-on-rails/actions/workflows/test.yml)
-[![Code Climate](https://codeclimate.com/github/ruby-grape/grape-on-rails.svg)](https://codeclimate.com/github/ruby-grape/grape-on-rails)
 
 A [Grape](http://github.com/ruby-grape/grape) API mounted on Rails.
 
@@ -21,3 +20,5 @@ rails s
 
 - Try http://localhost:3000/api/ping or http://localhost:3000/api/protected/ping with _username_ and _password_.
 - View Swagger docs at http://localhost:3000/swagger.
+- Try http://localhost:3000/api/headers to see request headers.
+
diff --git a/Rakefile b/Rakefile
index 8cff256..de48e7b 100644
--- a/Rakefile
+++ b/Rakefile
@@ -5,11 +5,15 @@ require_relative 'config/application'
 
 Rails.application.load_tasks
 
-if Rails.env.test? || Rails.env.development?
+if Rails.env.local?
   require 'rspec/core/rake_task'
 
   Rake::Task[:default].prerequisites.clear
 
+  RSpec::Core::RakeTask.new(:spec) do |spec|
+    spec.pattern = 'spec/**/*_spec.rb'
+  end
+
   require 'rubocop/rake_task'
   RuboCop::RakeTask.new(:rubocop)
 
diff --git a/config/boot.rb b/config/boot.rb
index b9e460c..45df75b 100644
--- a/config/boot.rb
+++ b/config/boot.rb
@@ -1,4 +1,5 @@
 ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../Gemfile', __dir__)
 
+require 'logger'
 require 'bundler/setup' # Set up gems listed in the Gemfile.
 require 'bootsnap/setup' # Speed up boot time by caching expensive operations.
diff --git a/config/environments/development.rb b/config/environments/development.rb
index e522e6e..c370445 100644
--- a/config/environments/development.rb
+++ b/config/environments/development.rb
@@ -67,4 +67,7 @@
 
   # Uncomment if you wish to allow Action Cable access from any origin.
   # config.action_cable.disable_request_forgery_protection = true
+
+  # Always preserve the full timezone rather than offset of the receiver.
+  config.active_support.to_time_preserves_timezone = :zone
 end
diff --git a/config/environments/production.rb b/config/environments/production.rb
index e2408b6..ae01e39 100644
--- a/config/environments/production.rb
+++ b/config/environments/production.rb
@@ -90,4 +90,7 @@
 
   # Do not dump schema after migrations.
   config.active_record.dump_schema_after_migration = false
+
+  # Always preserve the full timezone rather than offset of the receiver.
+  config.active_support.to_time_preserves_timezone = :zone
 end
diff --git a/config/environments/test.rb b/config/environments/test.rb
index 4795ec8..e797178 100644
--- a/config/environments/test.rb
+++ b/config/environments/test.rb
@@ -61,4 +61,7 @@
 
   # Annotate rendered view with file names.
   # config.action_view.annotate_rendered_view_with_filenames = true
+
+  # Always preserve the full timezone rather than offset of the receiver.
+  config.active_support.to_time_preserves_timezone = :zone
 end
diff --git a/db/schema.rb b/db/schema.rb
new file mode 100644
index 0000000..51471bb
--- /dev/null
+++ b/db/schema.rb
@@ -0,0 +1,16 @@
+# This file is auto-generated from the current state of the database. Instead
+# of editing this file, please use the migrations feature of Active Record to
+# incrementally modify your database, and then regenerate this schema definition.
+#
+# This file is the source Rails uses to define your schema when running `bin/rails
+# db:schema:load`. When creating a new database, `bin/rails db:schema:load` tends to
+# be faster and is potentially less error prone than running all of your
+# migrations from scratch. Old migrations may fail to apply correctly if those
+# migrations use external dependencies or application code.
+#
+# It's strongly recommended that you check this file into your version control system.
+
+ActiveRecord::Schema[8.0].define(version: 0) do
+  # These are extensions that must be enabled in order to support this database
+  enable_extension 'pg_catalog.plpgsql'
+end
diff --git a/gemfiles/rails_6_1.gemfile b/gemfiles/rails_6_1.gemfile
index 82f114d..435bb77 100644
--- a/gemfiles/rails_6_1.gemfile
+++ b/gemfiles/rails_6_1.gemfile
@@ -3,12 +3,12 @@
 source 'https://rubygems.org'
 
 gem 'bootsnap', require: false
-gem 'concurrent-ruby', '1.3.4'
-gem 'grape', '~> 2.1'
+gem 'concurrent-ruby'
+gem 'grape', '~> 2.4'
 gem 'grape-swagger'
 gem 'importmap-rails'
 gem 'jbuilder'
-gem 'pg', '~> 1.1'
+gem 'pg'
 gem 'puma'
 gem 'rails', '~> 6.1'
 gem 'sprockets-rails'
@@ -27,13 +27,14 @@ end
 
 group :test do
   gem 'capybara'
+  gem 'mutex_m'
   gem 'rspec'
   gem 'rspec-rails'
-  gem 'rubocop', '1.62.1'
+  gem 'rubocop'
   gem 'rubocop-capybara'
   gem 'rubocop-rails'
   gem 'rubocop-rake'
   gem 'rubocop-rspec'
   gem 'rubocop-rspec_rails'
-  gem 'selenium-webdriver', '4.20'
+  gem 'selenium-webdriver'
 end
diff --git a/gemfiles/rails_7.gemfile b/gemfiles/rails_7.gemfile
index 0b3bde8..b1818f0 100644
--- a/gemfiles/rails_7.gemfile
+++ b/gemfiles/rails_7.gemfile
@@ -3,12 +3,12 @@
 source 'https://rubygems.org'
 
 gem 'bootsnap', require: false
-gem 'concurrent-ruby', '1.3.4'
-gem 'grape', '~> 2.1'
+gem 'concurrent-ruby'
+gem 'grape', '~> 2.4'
 gem 'grape-swagger'
 gem 'importmap-rails'
 gem 'jbuilder'
-gem 'pg', '~> 1.1'
+gem 'pg'
 gem 'puma'
 gem 'rails', '~> 7.0'
 gem 'sprockets-rails'
@@ -27,13 +27,14 @@ end
 
 group :test do
   gem 'capybara'
+  gem 'mutex_m'
   gem 'rspec'
   gem 'rspec-rails'
-  gem 'rubocop', '1.62.1'
+  gem 'rubocop'
   gem 'rubocop-capybara'
   gem 'rubocop-rails'
   gem 'rubocop-rake'
   gem 'rubocop-rspec'
   gem 'rubocop-rspec_rails'
-  gem 'selenium-webdriver', '4.20'
+  gem 'selenium-webdriver'
 end
diff --git a/gemfiles/rails_6.gemfile b/gemfiles/rails_8.gemfile
similarity index 80%
rename from gemfiles/rails_6.gemfile
rename to gemfiles/rails_8.gemfile
index d6927b1..e438202 100644
--- a/gemfiles/rails_6.gemfile
+++ b/gemfiles/rails_8.gemfile
@@ -3,14 +3,14 @@
 source 'https://rubygems.org'
 
 gem 'bootsnap', require: false
-gem 'concurrent-ruby', '1.3.4'
-gem 'grape', '~> 2.1'
+gem 'concurrent-ruby'
+gem 'grape', '~> 2.4'
 gem 'grape-swagger'
 gem 'importmap-rails'
 gem 'jbuilder'
-gem 'pg', '~> 1.1'
+gem 'pg'
 gem 'puma'
-gem 'rails', '~> 6.0'
+gem 'rails', '~> 8.0'
 gem 'sprockets-rails'
 gem 'stimulus-rails'
 gem 'turbo-rails'
@@ -27,13 +27,14 @@ end
 
 group :test do
   gem 'capybara'
+  gem 'mutex_m'
   gem 'rspec'
   gem 'rspec-rails'
-  gem 'rubocop', '1.62.1'
+  gem 'rubocop'
   gem 'rubocop-capybara'
   gem 'rubocop-rails'
   gem 'rubocop-rake'
   gem 'rubocop-rspec'
   gem 'rubocop-rspec_rails'
-  gem 'selenium-webdriver', '4.20'
+  gem 'selenium-webdriver'
 end
diff --git a/gemfiles/rails_edge.gemfile b/gemfiles/rails_edge.gemfile
index 0573b37..eddaadf 100644
--- a/gemfiles/rails_edge.gemfile
+++ b/gemfiles/rails_edge.gemfile
@@ -3,12 +3,12 @@
 source 'https://rubygems.org'
 
 gem 'bootsnap', require: false
-gem 'concurrent-ruby', '1.3.4'
-gem 'grape', '~> 2.1'
+gem 'concurrent-ruby'
+gem 'grape', '~> 2.4'
 gem 'grape-swagger'
 gem 'importmap-rails'
 gem 'jbuilder'
-gem 'pg', '~> 1.1'
+gem 'pg'
 gem 'puma'
 gem 'rails', git: 'https://github.com/rails/rails.git'
 gem 'sprockets-rails'
@@ -27,13 +27,14 @@ end
 
 group :test do
   gem 'capybara'
+  gem 'mutex_m'
   gem 'rspec'
   gem 'rspec-rails'
-  gem 'rubocop', '1.62.1'
+  gem 'rubocop'
   gem 'rubocop-capybara'
   gem 'rubocop-rails'
   gem 'rubocop-rake'
   gem 'rubocop-rspec'
   gem 'rubocop-rspec_rails'
-  gem 'selenium-webdriver', '4.20'
+  gem 'selenium-webdriver'
 end