diff --git a/.github/workflows/maven.yml b/.github/workflows/maven.yml
index 8b7a1fad0..8cbeb0286 100644
--- a/.github/workflows/maven.yml
+++ b/.github/workflows/maven.yml
@@ -73,6 +73,7 @@ jobs:
           'rails71_rack22',
           'rails72_rack22',
           'rails80_rack22',
+          'rails81_rack22',
         ]
         jruby_version: [ '9.3.15.0', '9.4.15.0', '10.0.6.0', '10.1.1.0' ]
         java_version: [ '8', '11', '17', '21', '25' ]
@@ -99,6 +100,10 @@ jobs:
             jruby_version: '9.3.15.0'
           - appraisal: 'rails80_rack22' # Requires Ruby 3.4 compatibility, which JRuby 9.4 does not support
             jruby_version: '9.4.15.0'
+          - appraisal: 'rails81_rack22' # Requires Ruby 3.4 compatibility, which JRuby 9.3 does not support
+            jruby_version: '9.3.15.0'
+          - appraisal: 'rails81_rack22' # Requires Ruby 3.4 compatibility, which JRuby 9.4 does not support
+            jruby_version: '9.4.15.0'
       fail-fast: false
 
     env:
diff --git a/Appraisals b/Appraisals
index 70781847c..da0fa58af 100644
--- a/Appraisals
+++ b/Appraisals
@@ -11,6 +11,7 @@ version_spec = ->(prefix, desc) { "~> #{major_minor.call(prefix, desc)}.0" }
   "rails71" => {racks: %w[rack22]},
   "rails72" => {racks: %w[rack22]},
   "rails80" => {racks: %w[rack22]},
+  "rails81" => {racks: %w[rack22]}
 }.each do |rails_desc, c|
   c[:racks].each do |rack_desc|
 
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8a9b46b42..ffccccdf9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,8 @@
 - fix: JRuby::Rack::Input#read(0) should return an empty string
 - fix: close the original body when ShowStatus replaces it
 - fix: detect Transfer-Encoding/Content-Length headers case-insensitively
+- chore: revert `rack.version` value to be Rack 2.2 spec conformant
+- fix: do not mutate (potentially frozen) response header values when writing
 
 ## 1.2.8
 
diff --git a/Gemfile.lock b/Gemfile.lock
index e5c533f78..fde0e3c76 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -57,4 +57,4 @@ CHECKSUMS
   thor (1.5.0) sha256=e3a9e55fe857e44859ce104a84675ab6e8cd59c650a49106a05f55f136425e73
 
 BUNDLED WITH
-   2.7.2
+   2.6.3
diff --git a/README.md b/README.md
index f0110749a..e3f43f12a 100644
--- a/README.md
+++ b/README.md
@@ -16,7 +16,7 @@ For more information on Rack, visit http://rack.github.io/.
 
 | JRuby-Rack Series                                              | Status        | Rack      | JRuby      | Java | Rails     | Servlet API (min → mostly supported) | Notes |
 |----------------------------------------------------------------|---------------|-----------|------------|------|-----------|--------------------------------------|-------|
-| [**1.2**](https://github.com/jruby/jruby-rack/tree/1.2-stable) | EOL @ 2026-09 | 2.2       | 9.3 → 10.1 | 8+   | 5.0 → 8.0 | 3.0 → 4.0 (Java EE 6 → 7)            |       |
+| [**1.2**](https://github.com/jruby/jruby-rack/tree/1.2-stable) | EOL @ 2026-09 | 2.2       | 9.3 → 10.1 | 8+   | 5.0 → 8.1 | 3.0 → 4.0 (Java EE 6 → 7)            |       |
 | [**1.1**](https://github.com/jruby/jruby-rack/tree/1.1-stable) | EOL @ 2024-05 | 1.x → 2.2 | 1.6 → 9.4  | 6+   | 2.1 → 5.2 | 2.5 → 4.0 (Java EE 5 → 7)            |       |
 | [**1.0**](https://github.com/jruby/jruby-rack/tree/1.0.10)     | EOL @ 2011-11 | 0.9 → 1.x | 1.1 → 1.9  | 5+   | 2.1 → 3.x | 2.5 (Java EE 5)                      |       |
 
diff --git a/gemfiles/rails50_rack22.gemfile b/gemfiles/rails50_rack22.gemfile
index 5ebe0f45f..4a99d46e8 100644
--- a/gemfiles/rails50_rack22.gemfile
+++ b/gemfiles/rails50_rack22.gemfile
@@ -13,6 +13,7 @@ end
 
 group :development do
   gem "appraisal", require: nil
+  gem "rexml"
 end
 
 group :test do
diff --git a/gemfiles/rails52_rack22.gemfile b/gemfiles/rails52_rack22.gemfile
index 242654abf..8242bba4e 100644
--- a/gemfiles/rails52_rack22.gemfile
+++ b/gemfiles/rails52_rack22.gemfile
@@ -12,6 +12,7 @@ end
 
 group :development do
   gem "appraisal", require: nil
+  gem "rexml"
 end
 
 group :test do
diff --git a/gemfiles/rails60_rack22.gemfile b/gemfiles/rails60_rack22.gemfile
index b7d7b5c1d..e26305589 100644
--- a/gemfiles/rails60_rack22.gemfile
+++ b/gemfiles/rails60_rack22.gemfile
@@ -12,6 +12,7 @@ end
 
 group :development do
   gem "appraisal", require: nil
+  gem "rexml"
 end
 
 group :test do
diff --git a/gemfiles/rails61_rack22.gemfile b/gemfiles/rails61_rack22.gemfile
index 8009c3653..600306ab5 100644
--- a/gemfiles/rails61_rack22.gemfile
+++ b/gemfiles/rails61_rack22.gemfile
@@ -12,6 +12,7 @@ end
 
 group :development do
   gem "appraisal", require: nil
+  gem "rexml"
 end
 
 group :test do
diff --git a/gemfiles/rails70_rack22.gemfile b/gemfiles/rails70_rack22.gemfile
index b7b1c5dcd..27cf5e876 100644
--- a/gemfiles/rails70_rack22.gemfile
+++ b/gemfiles/rails70_rack22.gemfile
@@ -5,11 +5,11 @@ source "https://rubygems.org"
 group :default do
   gem "rack", "~> 2.2.0"
   gem "rails", "~> 7.0.0"
-  gem "rdoc", "!= 8.0.0"
 end
 
 group :development do
   gem "appraisal", require: nil
+  gem "rexml"
 end
 
 group :test do
diff --git a/gemfiles/rails71_rack22.gemfile b/gemfiles/rails71_rack22.gemfile
index d13b8451c..f9dce538e 100644
--- a/gemfiles/rails71_rack22.gemfile
+++ b/gemfiles/rails71_rack22.gemfile
@@ -5,11 +5,11 @@ source "https://rubygems.org"
 group :default do
   gem "rack", "~> 2.2.0"
   gem "rails", "~> 7.1.0"
-  gem "rdoc", "!= 8.0.0"
 end
 
 group :development do
   gem "appraisal", require: nil
+  gem "rexml"
 end
 
 group :test do
diff --git a/gemfiles/rails72_rack22.gemfile b/gemfiles/rails72_rack22.gemfile
index d70ca9e0d..5f93aaec8 100644
--- a/gemfiles/rails72_rack22.gemfile
+++ b/gemfiles/rails72_rack22.gemfile
@@ -9,6 +9,7 @@ end
 
 group :development do
   gem "appraisal", require: nil
+  gem "rexml"
 end
 
 group :test do
diff --git a/gemfiles/rails80_rack22.gemfile b/gemfiles/rails80_rack22.gemfile
index ce87d96c5..23603faa4 100644
--- a/gemfiles/rails80_rack22.gemfile
+++ b/gemfiles/rails80_rack22.gemfile
@@ -9,6 +9,7 @@ end
 
 group :development do
   gem "appraisal", require: nil
+  gem "rexml"
 end
 
 group :test do
diff --git a/gemfiles/rails81_rack22.gemfile b/gemfiles/rails81_rack22.gemfile
new file mode 100644
index 000000000..9549db803
--- /dev/null
+++ b/gemfiles/rails81_rack22.gemfile
@@ -0,0 +1,19 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+group :default do
+  gem "rack", "~> 2.2.0"
+  gem "rails", "~> 8.1.0"
+end
+
+group :development do
+  gem "appraisal", require: nil
+  gem "rexml"
+end
+
+group :test do
+  gem "rake", "~> 13.4", require: nil
+  gem "rspec"
+  gem "logger"
+end
diff --git a/src/main/java/org/jruby/rack/ext/Response.java b/src/main/java/org/jruby/rack/ext/Response.java
index 8c9bee154..c7aaed8c1 100644
--- a/src/main/java/org/jruby/rack/ext/Response.java
+++ b/src/main/java/org/jruby/rack/ext/Response.java
@@ -356,8 +356,7 @@ protected void writeStatus(final RackResponseEnvironment response) {
     }
 
     @JRubyMethod(name = "write_headers")
-    public IRubyObject write_headers(final ThreadContext context, final IRubyObject response)
-        throws IOException {
+    public IRubyObject write_headers(final ThreadContext context, final IRubyObject response) {
         writeHeaders(response.toJava(RackResponseEnvironment.class));
         return context.nil;
     }
@@ -406,7 +405,7 @@ public IRubyObject yield(ThreadContext context, IRubyObject[] args) {
 
                             @Override
                             public IRubyObject yield(ThreadContext context, IRubyObject value) {
-                                value.callMethod(context, "chomp!", newLine);
+                                value = value.callMethod(context, "chomp", newLine);
                                 response.addHeader(name, value.toString());
                                 return value;
                             }
@@ -439,10 +438,10 @@ public IRubyObject write_body(final ThreadContext context, final IRubyObject res
     }
 
     protected void writeBody(final RackResponseEnvironment response) throws IOException {
+        final ThreadContext context = currentContext();
         Channel bodyChannel = null; IRubyObject body = this.body;
         try {
             if ( body.respondsTo("call") && ! body.respondsTo("each") ) {
-                final ThreadContext context = currentContext();
                 final IRubyObject outputStream =
                     JavaUtil.convertJavaToRuby(context.runtime, response.getOutputStream());
                 this.body.callMethod(context, "call", outputStream);
@@ -450,7 +449,6 @@ protected void writeBody(final RackResponseEnvironment response) throws IOExcept
             }
 
             if ( body.respondsTo("to_path") ) { // send_file
-                final ThreadContext context = currentContext();
                 final IRubyObject path = body.callMethod(context, "to_path");
                 callMethod("send_file", path, JavaUtil.convertJavaToRuby(context.runtime, response));
                 return;
@@ -465,7 +463,6 @@ protected void writeBody(final RackResponseEnvironment response) throws IOExcept
                     bodyChannel = ((RubyIO) body).getChannel();
                 }
                 else {
-                    final ThreadContext context = currentContext();
                     final IRubyObject channel = body.callMethod(context, "to_channel");
                     bodyChannel = channel.toJava(Channel.class);
                 }
@@ -480,8 +477,6 @@ protected void writeBody(final RackResponseEnvironment response) throws IOExcept
             // NOTE: we no longer handle "to_inputstream" since in 1.7 "to_channel" covers those ...
 
             final OutputStream output = response.getOutputStream();
-            final ThreadContext context = currentContext();
-            IOException error = null;
             if ( doDechunk() ) {
                 final IRubyObject output_stream = JavaUtil.convertJavaToRuby(context.runtime, output);
                 callMethod(context, "write_body_dechunked", output_stream);
@@ -706,6 +701,7 @@ private void transferChannel(final ReadableByteChannel channel, final OutputStre
 
     ThreadContext currentContext() { return getRuntime().getCurrentContext(); }
 
+    @SuppressWarnings("UnusedReturnValue")
     static IRubyObject invoke(
         final ThreadContext context, final IRubyObject self,
         final String method, final BlockBody body) {
diff --git a/src/main/java/org/jruby/rack/util/IOHelpers.java b/src/main/java/org/jruby/rack/util/IOHelpers.java
index eec8f4d9d..2db8d1072 100644
--- a/src/main/java/org/jruby/rack/util/IOHelpers.java
+++ b/src/main/java/org/jruby/rack/util/IOHelpers.java
@@ -73,24 +73,6 @@ public static String inputStreamToString(final InputStream stream)
         return str.toString();
     }
 
-    public static ByteList readURL(final Ruby runtime, final URL url)
-        throws IOException {
-        if ( url == null ) return null;
-
-        final int chunk = 256;
-
-        final InputStream stream = url.openStream();
-        final ByteList bytes = new ByteList(chunk);
-
-        try {
-            while ( true ) bytes.append(stream, chunk);
-        }
-        catch (EOFException e) { /* read whole stream */ }
-        finally { stream.close(); }
-
-        return bytes;
-    }
-
     public static String rubyMagicCommentValue(final String script, final String prefix)
         throws IOException {
         if ( script == null ) return null;
@@ -100,7 +82,7 @@ public static String rubyMagicCommentValue(final String script, final String pre
         String line, comment = null; Pattern pattern = null;
         while ( (line = reader.readLine()) != null ) {
             // we only support (magic) comments at the beginning :
-            if ( line.length() == 0 || line.charAt(0) != '#' ) break;
+            if (line.isEmpty() || line.charAt(0) != '#' ) break;
 
             if (pattern == null) {
                 pattern = Pattern.compile(prefix + "\\s*(\\S+)");
diff --git a/src/spec/ruby/jruby/rack/integration_spec.rb b/src/spec/ruby/jruby/rack/integration_spec.rb
index c30982598..9f91fc939 100644
--- a/src/spec/ruby/jruby/rack/integration_spec.rb
+++ b/src/spec/ruby/jruby/rack/integration_spec.rb
@@ -225,6 +225,10 @@
     it_should_behave_like 'a rails app'
   end
 
+  describe 'rails 8.1', lib: :rails81 do
+    it_should_behave_like 'a rails app'
+  end
+
   def expect_to_have_monkey_patched_chunked
     @runtime.evalScriptlet "require 'rack/chunked'"
     script = %{
diff --git a/src/spec/ruby/jruby/rack/response_spec.rb b/src/spec/ruby/jruby/rack/response_spec.rb
index eb44b8731..3310ac9f1 100644
--- a/src/spec/ruby/jruby/rack/response_spec.rb
+++ b/src/spec/ruby/jruby/rack/response_spec.rb
@@ -86,6 +86,13 @@ class << value
     response.write_headers(response_environment)
   end
 
+  it "writes frozen header values containing newlines without raising" do
+    response.to_java.getHeaders.update({ "Set-Cookie" => "cookie1\ncookie2".freeze })
+    expect(servlet_response).to receive(:addHeader).with("Set-Cookie", "cookie1")
+    expect(servlet_response).to receive(:addHeader).with("Set-Cookie", "cookie2")
+    response.write_headers(response_environment)
+  end
+
   it "adds an int header when values is a fixnum" do
     update_response_headers "Expires" => 0
     expect(response_environment).to receive(:addIntHeader).with("Expires", 0)
diff --git a/src/spec/ruby/rack/handler/servlet_lint_spec.rb b/src/spec/ruby/rack/handler/servlet_lint_spec.rb
new file mode 100644
index 000000000..b3394f2ec
--- /dev/null
+++ b/src/spec/ruby/rack/handler/servlet_lint_spec.rb
@@ -0,0 +1,75 @@
+#--
+# This source code is available under the MIT license.
+# See the file LICENSE.txt for details.
+#++
+
+require File.expand_path('../../spec_helper', File.dirname(__FILE__))
+
+require 'rack'
+require 'rack/lint'
+require 'uri'
+require 'rack/handler/servlet'
+
+# End-to-end conformance check: the env built from the servlet request and the
+# handling of the (Lint wrapped) response must satisfy the loaded Rack version's
+# SPEC - Rack::Lint raises when either side of the contract is broken.
+describe 'Rack::Handler::Servlet (Rack::Lint)' do
+
+  before :each do
+    @servlet_context = mock_servlet_context
+    allow(@rack_context).to receive(:getServerInfo).and_return 'Mock-Container/1.0'
+    @servlet_request = org.springframework.mock.web.MockHttpServletRequest.new(@servlet_context)
+    @servlet_response = org.springframework.mock.web.MockHttpServletResponse.new
+    @servlet_env = org.jruby.rack.servlet.ServletRackEnvironment.new(
+      @servlet_request, @servlet_response, @rack_context
+    )
+
+    @servlet_request.setMethod('GET')
+    @servlet_request.setContextPath('')
+    @servlet_request.setRequestURI('/some/path')
+    @servlet_request.setQueryString('a=1&b=2')
+    @servlet_request.addParameter('a', '1')
+    @servlet_request.addParameter('b', '2')
+    @servlet_request.setServerName('lint.example.com')
+    @servlet_request.setServerPort(8080)
+    @servlet_request.setProtocol('HTTP/1.1')
+    @servlet_request.setRemoteAddr('127.0.0.1')
+    @servlet_request.setContent(''.to_java_bytes)
+    @servlet_request.addHeader('Accept', 'text/plain')
+  end
+
+  let(:inner_app) do
+    lambda do |env|
+      env['rack.input'].read # exercises the Lint wrapped input contract
+      [ 200, { 'Content-Type' => 'text/plain', 'Content-Length' => '2' }, [ 'OK' ] ]
+    end
+  end
+
+  let(:servlet) { Rack::Handler::Servlet.new Rack::Lint.new(inner_app) }
+
+  shared_examples 'lint-compatible env' do
+
+    it "creates a SPEC compatible env and writes the response" do
+      response = servlet.call(@servlet_env)
+      expect(response.to_java.getStatus).to eql 200
+
+      response_env = org.jruby.rack.servlet.ServletRackResponseEnvironment.new(@servlet_response)
+      response.to_java.respond(response_env)
+      expect(@servlet_response.getStatus).to eql 200
+      expect(@servlet_response.getContentAsString).to eql 'OK'
+    end
+
+  end
+
+  describe 'with (default) env' do
+    it_behaves_like 'lint-compatible env'
+  end
+
+  describe 'with servlet env' do
+    before { Rack::Handler::Servlet.env = :servlet }
+    after { Rack::Handler::Servlet.env = nil }
+
+    it_behaves_like 'lint-compatible env'
+  end
+
+end
diff --git a/src/spec/stub/rails81/app/controllers/application_controller.rb b/src/spec/stub/rails81/app/controllers/application_controller.rb
new file mode 100644
index 000000000..0d95db22b
--- /dev/null
+++ b/src/spec/stub/rails81/app/controllers/application_controller.rb
@@ -0,0 +1,4 @@
+class ApplicationController < ActionController::Base
+  # Only allow modern browsers supporting webp images, web push, badges, import maps, CSS nesting, and CSS :has.
+  allow_browser versions: :modern
+end
diff --git a/src/spec/stub/rails81/app/helpers/application_helper.rb b/src/spec/stub/rails81/app/helpers/application_helper.rb
new file mode 100644
index 000000000..de6be7945
--- /dev/null
+++ b/src/spec/stub/rails81/app/helpers/application_helper.rb
@@ -0,0 +1,2 @@
+module ApplicationHelper
+end
diff --git a/src/spec/stub/rails81/config/application.rb b/src/spec/stub/rails81/config/application.rb
new file mode 100644
index 000000000..bba537d7f
--- /dev/null
+++ b/src/spec/stub/rails81/config/application.rb
@@ -0,0 +1,42 @@
+require_relative "boot"
+
+require "rails"
+# Pick the frameworks you want:
+require "active_model/railtie"
+# require "active_job/railtie"
+# require "active_record/railtie"
+# require "active_storage/engine"
+require "action_controller/railtie"
+# require "action_mailer/railtie"
+# require "action_mailbox/engine"
+# require "action_text/engine"
+require "action_view/railtie"
+# require "action_cable/engine"
+# require "rails/test_unit/railtie"
+
+# Require the gems listed in Gemfile, including any gems
+# you've limited to :test, :development, or :production.
+Bundler.require(*Rails.groups)
+
+module Rails81
+  class Application < Rails::Application
+    # Initialize configuration defaults for originally generated Rails version.
+    config.load_defaults 8.1
+
+    # Please, add to the `ignore` list any other `lib` subdirectories that do
+    # not contain `.rb` files, or that should not be reloaded or eager loaded.
+    # Common ones are `templates`, `generators`, or `middleware`, for example.
+    config.autoload_lib(ignore: %w[assets tasks])
+
+    # Configuration for the application, engines, and railties goes here.
+    #
+    # These settings can be overridden in specific environments using the files
+    # in config/environments, which are processed later.
+    #
+    # config.time_zone = "Central Time (US & Canada)"
+    # config.eager_load_paths << Rails.root.join("extras")
+
+    # Don't generate system test files.
+    config.generators.system_tests = nil
+  end
+end
diff --git a/src/spec/stub/rails81/config/boot.rb b/src/spec/stub/rails81/config/boot.rb
new file mode 100644
index 000000000..282011619
--- /dev/null
+++ b/src/spec/stub/rails81/config/boot.rb
@@ -0,0 +1,3 @@
+ENV["BUNDLE_GEMFILE"] ||= File.expand_path("../Gemfile", __dir__)
+
+require "bundler/setup" # Set up gems listed in the Gemfile.
diff --git a/src/spec/stub/rails81/config/credentials.yml.enc b/src/spec/stub/rails81/config/credentials.yml.enc
new file mode 100644
index 000000000..e67e3468f
--- /dev/null
+++ b/src/spec/stub/rails81/config/credentials.yml.enc
@@ -0,0 +1 @@
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--Jp0qmDUTnghki/m1--9Dp76qUD7YblOugS/mioww==
\ No newline at end of file
diff --git a/src/spec/stub/rails81/config/environment.rb b/src/spec/stub/rails81/config/environment.rb
new file mode 100644
index 000000000..cac531577
--- /dev/null
+++ b/src/spec/stub/rails81/config/environment.rb
@@ -0,0 +1,5 @@
+# Load the Rails application.
+require_relative "application"
+
+# Initialize the Rails application.
+Rails.application.initialize!
diff --git a/src/spec/stub/rails81/config/environments/development.rb b/src/spec/stub/rails81/config/environments/development.rb
new file mode 100644
index 000000000..f68dd3575
--- /dev/null
+++ b/src/spec/stub/rails81/config/environments/development.rb
@@ -0,0 +1,42 @@
+require "active_support/core_ext/integer/time"
+
+Rails.application.configure do
+  # Settings specified here will take precedence over those in config/application.rb.
+
+  # Make code changes take effect immediately without server restart.
+  config.enable_reloading = true
+
+  # Do not eager load code on boot.
+  config.eager_load = false
+
+  # Show full error reports.
+  config.consider_all_requests_local = true
+
+  # Enable server timing.
+  config.server_timing = true
+
+  # Enable/disable Action Controller caching. By default Action Controller caching is disabled.
+  # Run rails dev:cache to toggle Action Controller caching.
+  if Rails.root.join("tmp/caching-dev.txt").exist?
+    config.action_controller.perform_caching = true
+    config.action_controller.enable_fragment_cache_logging = true
+    config.public_file_server.headers = { "cache-control" => "public, max-age=#{2.days.to_i}" }
+  else
+    config.action_controller.perform_caching = false
+  end
+
+  # Change to :null_store to avoid any caching.
+  config.cache_store = :memory_store
+
+  # Print deprecation notices to the Rails logger.
+  config.active_support.deprecation = :log
+
+  # Raises error for missing translations.
+  # config.i18n.raise_on_missing_translations = true
+
+  # Annotate rendered view with file names.
+  config.action_view.annotate_rendered_view_with_filenames = true
+
+  # Raise error when a before_action's only/except options reference missing actions.
+  config.action_controller.raise_on_missing_callback_actions = true
+end
diff --git a/src/spec/stub/rails81/config/environments/production.rb b/src/spec/stub/rails81/config/environments/production.rb
new file mode 100644
index 000000000..49ed6ab53
--- /dev/null
+++ b/src/spec/stub/rails81/config/environments/production.rb
@@ -0,0 +1,73 @@
+require "active_support/core_ext/integer/time"
+
+Rails.application.configure do
+  # Settings specified here will take precedence over those in config/application.rb.
+
+  # Code is not reloaded between requests.
+  config.enable_reloading = false
+
+  # Eager load code on boot for better performance and memory savings (ignored by Rake tasks).
+  config.eager_load = true
+
+  # Full error reports are disabled.
+  config.consider_all_requests_local = false
+
+  # Turn on fragment caching in view templates.
+  config.action_controller.perform_caching = true
+
+  # Cache digest stamped assets for far-future expiry.
+  # Short cache for others: robots.txt, sitemap.xml, 404.html, etc.
+  config.public_file_server.headers = {
+    "cache-control" => lambda do |path, _|
+      if path.start_with?("/assets/")
+        # Files in /assets/ are expected to be fully immutable.
+        # If the content change the URL too.
+        "public, immutable, max-age=#{1.year.to_i}"
+      else
+        # For anything else we cache for 1 minute.
+        "public, max-age=#{1.minute.to_i}, stale-while-revalidate=#{5.minutes.to_i}"
+      end
+    end
+  }
+
+  # Enable serving of images, stylesheets, and JavaScripts from an asset server.
+  # config.asset_host = "http://assets.example.com"
+
+  # Assume all access to the app is happening through a SSL-terminating reverse proxy.
+  config.assume_ssl = true
+
+  # Force all access to the app over SSL, use Strict-Transport-Security, and use secure cookies.
+  config.force_ssl = true
+
+  # Skip http-to-https redirect for the default health check endpoint.
+  # config.ssl_options = { redirect: { exclude: ->(request) { request.path == "/up" } } }
+
+  # Log to STDOUT with the current request id as a default log tag.
+  config.log_tags = [ :request_id ]
+  # config.logger   = ActiveSupport::TaggedLogging.logger(STDOUT)
+
+  # Change to "debug" to log everything (including potentially personally-identifiable information!).
+  config.log_level = ENV.fetch("RAILS_LOG_LEVEL", "info")
+
+  # Prevent health checks from clogging up the logs.
+  config.silence_healthcheck_path = "/up"
+
+  # Don't log any deprecations.
+  config.active_support.report_deprecations = false
+
+  # Replace the default in-process memory cache store with a durable alternative.
+  # config.cache_store = :mem_cache_store
+
+  # Enable locale fallbacks for I18n (makes lookups for any locale fall back to
+  # the I18n.default_locale when a translation cannot be found).
+  config.i18n.fallbacks = true
+
+  # Enable DNS rebinding protection and other `Host` header attacks.
+  # config.hosts = [
+  #   "example.com",     # Allow requests from example.com
+  #   /.*\.example\.com/ # Allow requests from subdomains like `www.example.com`
+  # ]
+  #
+  # Skip DNS rebinding protection for the default health check endpoint.
+  # config.host_authorization = { exclude: ->(request) { request.path == "/up" } }
+end
diff --git a/src/spec/stub/rails81/config/environments/test.rb b/src/spec/stub/rails81/config/environments/test.rb
new file mode 100644
index 000000000..14bc29e06
--- /dev/null
+++ b/src/spec/stub/rails81/config/environments/test.rb
@@ -0,0 +1,42 @@
+# The test environment is used exclusively to run your application's
+# test suite. You never need to work with it otherwise. Remember that
+# your test database is "scratch space" for the test suite and is wiped
+# and recreated between test runs. Don't rely on the data there!
+
+Rails.application.configure do
+  # Settings specified here will take precedence over those in config/application.rb.
+
+  # While tests run files are not watched, reloading is not necessary.
+  config.enable_reloading = false
+
+  # Eager loading loads your entire application. When running a single test locally,
+  # this is usually not necessary, and can slow down your test suite. However, it's
+  # recommended that you enable it in continuous integration systems to ensure eager
+  # loading is working properly before deploying your code.
+  config.eager_load = ENV["CI"].present?
+
+  # Configure public file server for tests with cache-control for performance.
+  config.public_file_server.headers = { "cache-control" => "public, max-age=3600" }
+
+  # Show full error reports.
+  config.consider_all_requests_local = true
+  config.cache_store = :null_store
+
+  # Render exception templates for rescuable exceptions and raise for other exceptions.
+  config.action_dispatch.show_exceptions = :rescuable
+
+  # Disable request forgery protection in test environment.
+  config.action_controller.allow_forgery_protection = false
+
+  # Print deprecation notices to the stderr.
+  config.active_support.deprecation = :stderr
+
+  # Raises error for missing translations.
+  # config.i18n.raise_on_missing_translations = true
+
+  # Annotate rendered view with file names.
+  # config.action_view.annotate_rendered_view_with_filenames = true
+
+  # Raise error when a before_action's only/except options reference missing actions.
+  config.action_controller.raise_on_missing_callback_actions = true
+end
diff --git a/src/spec/stub/rails81/config/initializers/content_security_policy.rb b/src/spec/stub/rails81/config/initializers/content_security_policy.rb
new file mode 100644
index 000000000..d51d71397
--- /dev/null
+++ b/src/spec/stub/rails81/config/initializers/content_security_policy.rb
@@ -0,0 +1,29 @@
+# Be sure to restart your server when you modify this file.
+
+# Define an application-wide content security policy.
+# See the Securing Rails Applications Guide for more information:
+# https://guides.rubyonrails.org/security.html#content-security-policy-header
+
+# Rails.application.configure do
+#   config.content_security_policy do |policy|
+#     policy.default_src :self, :https
+#     policy.font_src    :self, :https, :data
+#     policy.img_src     :self, :https, :data
+#     policy.object_src  :none
+#     policy.script_src  :self, :https
+#     policy.style_src   :self, :https
+#     # Specify URI for violation reports
+#     # policy.report_uri "/csp-violation-report-endpoint"
+#   end
+#
+#   # Generate session nonces for permitted importmap, inline scripts, and inline styles.
+#   config.content_security_policy_nonce_generator = ->(request) { request.session.id.to_s }
+#   config.content_security_policy_nonce_directives = %w(script-src style-src)
+#
+#   # Automatically add `nonce` to `javascript_tag`, `javascript_include_tag`, and `stylesheet_link_tag`
+#   # if the corresponding directives are specified in `content_security_policy_nonce_directives`.
+#   # config.content_security_policy_nonce_auto = true
+#
+#   # Report violations without enforcing the policy.
+#   # config.content_security_policy_report_only = true
+# end
diff --git a/src/spec/stub/rails81/config/initializers/filter_parameter_logging.rb b/src/spec/stub/rails81/config/initializers/filter_parameter_logging.rb
new file mode 100644
index 000000000..c0b717f7e
--- /dev/null
+++ b/src/spec/stub/rails81/config/initializers/filter_parameter_logging.rb
@@ -0,0 +1,8 @@
+# Be sure to restart your server when you modify this file.
+
+# Configure parameters to be partially matched (e.g. passw matches password) and filtered from the log file.
+# Use this to limit dissemination of sensitive information.
+# See the ActiveSupport::ParameterFilter documentation for supported notations and behaviors.
+Rails.application.config.filter_parameters += [
+  :passw, :email, :secret, :token, :_key, :crypt, :salt, :certificate, :otp, :ssn, :cvv, :cvc
+]
diff --git a/src/spec/stub/rails81/config/initializers/inflections.rb b/src/spec/stub/rails81/config/initializers/inflections.rb
new file mode 100644
index 000000000..3860f659e
--- /dev/null
+++ b/src/spec/stub/rails81/config/initializers/inflections.rb
@@ -0,0 +1,16 @@
+# Be sure to restart your server when you modify this file.
+
+# Add new inflection rules using the following format. Inflections
+# are locale specific, and you may define rules for as many different
+# locales as you wish. All of these examples are active by default:
+# ActiveSupport::Inflector.inflections(:en) do |inflect|
+#   inflect.plural /^(ox)$/i, "\\1en"
+#   inflect.singular /^(ox)en/i, "\\1"
+#   inflect.irregular "person", "people"
+#   inflect.uncountable %w( fish sheep )
+# end
+
+# These inflection rules are supported but not enabled by default:
+# ActiveSupport::Inflector.inflections(:en) do |inflect|
+#   inflect.acronym "RESTful"
+# end
diff --git a/src/spec/stub/rails81/config/locales/en.yml b/src/spec/stub/rails81/config/locales/en.yml
new file mode 100644
index 000000000..6c349ae5e
--- /dev/null
+++ b/src/spec/stub/rails81/config/locales/en.yml
@@ -0,0 +1,31 @@
+# Files in the config/locales directory are used for internationalization and
+# are automatically loaded by Rails. If you want to use locales other than
+# English, add the necessary files in this directory.
+#
+# To use the locales, use `I18n.t`:
+#
+#     I18n.t "hello"
+#
+# In views, this is aliased to just `t`:
+#
+#     <%= t("hello") %>
+#
+# To use a different locale, set it with `I18n.locale`:
+#
+#     I18n.locale = :es
+#
+# This would use the information in config/locales/es.yml.
+#
+# To learn more about the API, please read the Rails Internationalization guide
+# at https://guides.rubyonrails.org/i18n.html.
+#
+# Be aware that YAML interprets the following case-insensitive strings as
+# booleans: `true`, `false`, `on`, `off`, `yes`, `no`. Therefore, these strings
+# must be quoted to be interpreted as strings. For example:
+#
+#     en:
+#       "yes": yup
+#       enabled: "ON"
+
+en:
+  hello: "Hello world"
diff --git a/src/spec/stub/rails81/config/master.key b/src/spec/stub/rails81/config/master.key
new file mode 100644
index 000000000..e7883e7b5
--- /dev/null
+++ b/src/spec/stub/rails81/config/master.key
@@ -0,0 +1 @@
+c8efa0d2b5305bf19054185dc011f0f7
\ No newline at end of file
diff --git a/src/spec/stub/rails81/config/routes.rb b/src/spec/stub/rails81/config/routes.rb
new file mode 100644
index 000000000..48254e88e
--- /dev/null
+++ b/src/spec/stub/rails81/config/routes.rb
@@ -0,0 +1,14 @@
+Rails.application.routes.draw do
+  # Define your application routes per the DSL in https://guides.rubyonrails.org/routing.html
+
+  # Reveal health status on /up that returns 200 if the app boots with no exceptions, otherwise 500.
+  # Can be used by load balancers and uptime monitors to verify that the app is live.
+  get "up" => "rails/health#show", as: :rails_health_check
+
+  # Render dynamic PWA files from app/views/pwa/* (remember to link manifest in application.html.erb)
+  # get "manifest" => "rails/pwa#manifest", as: :pwa_manifest
+  # get "service-worker" => "rails/pwa#service_worker", as: :pwa_service_worker
+
+  # Defines the root path route ("/")
+  # root "posts#index"
+end
diff --git a/src/spec/stub/rails81/public/robots.txt b/src/spec/stub/rails81/public/robots.txt
new file mode 100644
index 000000000..c19f78ab6
--- /dev/null
+++ b/src/spec/stub/rails81/public/robots.txt
@@ -0,0 +1 @@
+# See https://www.robotstxt.org/robotstxt.html for documentation on how to use the robots.txt file