From 3fe7d4b990acc8839843f0771fc2570b2e3d7cf2 Mon Sep 17 00:00:00 2001
From: Richard Wang <wangrch@amazon.com>
Date: Thu, 3 Jul 2025 11:41:32 -0700
Subject: [PATCH 01/13] Add user agent plugin and test

---
 .../lib/smithy-client/plugins/user_agent.rb   | 59 +++++++++++++++++++
 .../smithy-client/plugins/user_agent_spec.rb  | 32 ++++++++++
 gems/smithy/lib/smithy/welds/plugins.rb       |  4 +-
 3 files changed, 94 insertions(+), 1 deletion(-)
 create mode 100644 gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
 create mode 100644 gems/smithy-client/spec/smithy-client/plugins/user_agent_spec.rb

diff --git a/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb b/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
new file mode 100644
index 000000000..378ef7c3e
--- /dev/null
+++ b/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
@@ -0,0 +1,59 @@
+# frozen_string_literal: true
+
+module Smithy
+  module Client
+    module Plugins
+      class UserAgent < Plugin
+        class Handler < Client::Handler
+          def call(context)
+            set_user_agent(context)
+            @handler.call(context)
+          end
+
+          def set_user_agent(context)
+            context.http_request.headers['User-Agent'] = UserAgent.new(context).to_s
+          end
+
+          class UserAgent
+            def initialize(context)
+              @context = context
+            end
+
+            def to_s
+              ua = "smithy-ruby/#{File.read(File.expand_path('../../../VERSION', __dir__)).strip}"
+              ua += " #{os_metadata}"
+              ua += " #{language_metadata}"
+              ua.strip
+            end
+
+            private
+
+            def os_metadata
+              os =
+                case RbConfig::CONFIG['host_os']
+                when /mac|darwin/
+                  'macos'
+                when /linux|cygwin/
+                  'linux'
+                when /mingw|mswin/
+                  'windows'
+                else
+                  'other'
+                end
+              metadata = "os/#{os}"
+              local_version = Gem::Platform.local.version
+              metadata += "##{local_version}" if local_version
+              metadata + " md/#{RbConfig::CONFIG['host_cpu']}"
+            end
+
+            def language_metadata
+              "lang/#{RUBY_ENGINE}##{RUBY_ENGINE_VERSION} md/#{RUBY_VERSION}"
+            end
+          end
+        end
+
+        handler(Handler, step: :sign, priority: 5)
+      end
+    end
+  end
+end
diff --git a/gems/smithy-client/spec/smithy-client/plugins/user_agent_spec.rb b/gems/smithy-client/spec/smithy-client/plugins/user_agent_spec.rb
new file mode 100644
index 000000000..098053978
--- /dev/null
+++ b/gems/smithy-client/spec/smithy-client/plugins/user_agent_spec.rb
@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+require_relative '../../spec_helper'
+
+require 'smithy-client/plugins/user_agent'
+
+module Smithy
+  module Client
+    module Plugins
+      describe UserAgent do
+        let(:client_class) do
+          client_class = ClientHelper.sample_client.const_get(:Client)
+          client_class.clear_plugins
+          client_class.add_plugin(DummySendPlugin)
+          client_class.add_plugin(UserAgent)
+          client_class
+        end
+
+        let(:client) { client_class.new }
+
+        it 'adds user agent header to request' do
+          resp = client.operation
+          ua_header = resp.context.http_request.headers['user-agent']
+          expect(ua_header).to_not be_nil
+          expect(ua_header).to include('smithy-ruby')
+          expect(ua_header).to include('os')
+          expect(ua_header).to include('lang/ruby')
+        end
+      end
+    end
+  end
+end
\ No newline at end of file
diff --git a/gems/smithy/lib/smithy/welds/plugins.rb b/gems/smithy/lib/smithy/welds/plugins.rb
index c84ce6380..305901547 100644
--- a/gems/smithy/lib/smithy/welds/plugins.rb
+++ b/gems/smithy/lib/smithy/welds/plugins.rb
@@ -17,6 +17,7 @@
 require 'smithy-client/plugins/retry_errors'
 require 'smithy-client/plugins/sign_requests'
 require 'smithy-client/plugins/stub_responses'
+require 'smithy-client/plugins/user_agent'
 
 module Smithy
   module Welds
@@ -46,7 +47,8 @@ def add_plugins
           Smithy::Client::Plugins::ResponseTarget => { require_path: "#{base_path}/response_target" },
           Smithy::Client::Plugins::RetryErrors => { require_path: "#{base_path}/retry_errors" },
           Smithy::Client::Plugins::SignRequests => { require_path: "#{base_path}/sign_requests" },
-          Smithy::Client::Plugins::StubResponses => { require_path: "#{base_path}/stub_responses" }
+          Smithy::Client::Plugins::StubResponses => { require_path: "#{base_path}/stub_responses" },
+          Smithy::Client::Plugins::UserAgent => { require_path: "#{base_path}/user_agent" }
         }
       end
     end

From ce6a7c0807c1d6c81ae7f77a810e4bd925067715 Mon Sep 17 00:00:00 2001
From: Richard Wang <wangrch@amazon.com>
Date: Mon, 7 Jul 2025 09:37:17 -0700
Subject: [PATCH 02/13] Reformat header

---
 .../lib/smithy-client/plugins/user_agent.rb        | 14 +++++++-------
 .../spec/smithy-client/plugins/user_agent_spec.rb  |  4 ++--
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb b/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
index 378ef7c3e..95ab6a3aa 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
@@ -11,7 +11,7 @@ def call(context)
           end
 
           def set_user_agent(context)
-            context.http_request.headers['User-Agent'] = UserAgent.new(context).to_s
+            context.http_request.headers['User-Agent'] = UserAgent.new(context)
           end
 
           class UserAgent
@@ -20,8 +20,8 @@ def initialize(context)
             end
 
             def to_s
-              ua = "smithy-ruby/#{File.read(File.expand_path('../../../VERSION', __dir__)).strip}"
-              ua += " #{os_metadata}"
+              ua = "smithy-ruby/#{Smithy::Client::VERSION}"
+              ua += " (#{os_metadata})"
               ua += " #{language_metadata}"
               ua.strip
             end
@@ -40,14 +40,14 @@ def os_metadata
                 else
                   'other'
                 end
-              metadata = "os/#{os}"
+              metadata = os.to_s
               local_version = Gem::Platform.local.version
-              metadata += "##{local_version}" if local_version
-              metadata + " md/#{RbConfig::CONFIG['host_cpu']}"
+              metadata += " #{local_version}" if local_version
+              metadata + "; #{RbConfig::CONFIG['host_cpu']}"
             end
 
             def language_metadata
-              "lang/#{RUBY_ENGINE}##{RUBY_ENGINE_VERSION} md/#{RUBY_VERSION}"
+              "ruby/#{RUBY_VERSION}"
             end
           end
         end
diff --git a/gems/smithy-client/spec/smithy-client/plugins/user_agent_spec.rb b/gems/smithy-client/spec/smithy-client/plugins/user_agent_spec.rb
index 098053978..9ef204b7d 100644
--- a/gems/smithy-client/spec/smithy-client/plugins/user_agent_spec.rb
+++ b/gems/smithy-client/spec/smithy-client/plugins/user_agent_spec.rb
@@ -23,8 +23,8 @@ module Plugins
           ua_header = resp.context.http_request.headers['user-agent']
           expect(ua_header).to_not be_nil
           expect(ua_header).to include('smithy-ruby')
-          expect(ua_header).to include('os')
-          expect(ua_header).to include('lang/ruby')
+          expect(ua_header).to include('macos').or include('linux').or include('windows').or include('other')
+          expect(ua_header).to include('ruby')
         end
       end
     end

From 90a5dfe415415f93e85bb55719a4f7e8144a0179 Mon Sep 17 00:00:00 2001
From: Richard Wang <wangrch@amazon.com>
Date: Mon, 7 Jul 2025 11:31:57 -0700
Subject: [PATCH 03/13] Reformat

---
 gems/smithy-client/lib/smithy-client/plugins/user_agent.rb | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb b/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
index 95ab6a3aa..986c01f69 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
@@ -21,8 +21,8 @@ def initialize(context)
 
             def to_s
               ua = "smithy-ruby/#{Smithy::Client::VERSION}"
-              ua += " (#{os_metadata})"
-              ua += " #{language_metadata}"
+              ua += " (#{os_metadata};"
+              ua += " #{language_metadata})"
               ua.strip
             end
 

From 70d742171893078ee9f19699f965aa0ca5e35bc2 Mon Sep 17 00:00:00 2001
From: Richard Wang <wangrch@amazon.com>
Date: Tue, 8 Jul 2025 08:37:29 -0700
Subject: [PATCH 04/13] Fix weld plugins after merge

---
 gems/smithy/lib/smithy/welds/plugins.rb | 1 -
 1 file changed, 1 deletion(-)

diff --git a/gems/smithy/lib/smithy/welds/plugins.rb b/gems/smithy/lib/smithy/welds/plugins.rb
index a297dedf9..ffc2cb583 100644
--- a/gems/smithy/lib/smithy/welds/plugins.rb
+++ b/gems/smithy/lib/smithy/welds/plugins.rb
@@ -47,7 +47,6 @@ def add_plugins
           Smithy::Client::Plugins::ResolveAuth => { require_path: "#{base_path}/resolve_auth" },
           Smithy::Client::Plugins::ResponseTarget => { require_path: "#{base_path}/response_target" },
           Smithy::Client::Plugins::RetryErrors => { require_path: "#{base_path}/retry_errors" },
-          Smithy::Client::Plugins::SignRequests => { require_path: "#{base_path}/sign_requests" },
           Smithy::Client::Plugins::StubResponses => { require_path: "#{base_path}/stub_responses" },
           Smithy::Client::Plugins::UserAgent => { require_path: "#{base_path}/user_agent" }
         }

From d5ce19ba50bc12c4ea7141fe693e2294cbf8e719 Mon Sep 17 00:00:00 2001
From: Richard Wang <wangrch@amazon.com>
Date: Wed, 9 Jul 2025 13:50:45 -0700
Subject: [PATCH 05/13] Add user agent suffix

---
 gems/smithy-client/lib/smithy-client/plugins/user_agent.rb | 3 +++
 .../spec/smithy-client/plugins/user_agent_spec.rb          | 7 +++++++
 2 files changed, 10 insertions(+)

diff --git a/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb b/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
index 986c01f69..661fb5198 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
@@ -4,6 +4,8 @@ module Smithy
   module Client
     module Plugins
       class UserAgent < Plugin
+        option(:user_agent_suffix)
+
         class Handler < Client::Handler
           def call(context)
             set_user_agent(context)
@@ -23,6 +25,7 @@ def to_s
               ua = "smithy-ruby/#{Smithy::Client::VERSION}"
               ua += " (#{os_metadata};"
               ua += " #{language_metadata})"
+              ua += " #{@context.config.user_agent_suffix}" if @context.config.user_agent_suffix
               ua.strip
             end
 
diff --git a/gems/smithy-client/spec/smithy-client/plugins/user_agent_spec.rb b/gems/smithy-client/spec/smithy-client/plugins/user_agent_spec.rb
index 9ef204b7d..997fb5312 100644
--- a/gems/smithy-client/spec/smithy-client/plugins/user_agent_spec.rb
+++ b/gems/smithy-client/spec/smithy-client/plugins/user_agent_spec.rb
@@ -26,6 +26,13 @@ module Plugins
           expect(ua_header).to include('macos').or include('linux').or include('windows').or include('other')
           expect(ua_header).to include('ruby')
         end
+
+        it 'adds user agent suffix to user agent string when configured' do
+          client = client_class.new(user_agent_suffix: 'test-suffix')
+          resp = client.operation
+          ua_header = resp.context.http_request.headers['user-agent']
+          expect(ua_header).to end_with('test-suffix')
+        end
       end
     end
   end

From fcd5ab774009569d0a948919dc9dbcca62f0a1f4 Mon Sep 17 00:00:00 2001
From: Richard Wang <wangrch@amazon.com>
Date: Thu, 10 Jul 2025 09:10:07 -0700
Subject: [PATCH 06/13] PR comments

---
 .../lib/smithy-client/plugins/user_agent.rb   | 15 +++++++++------
 .../smithy-client/plugins/user_agent_spec.rb  | 19 ++++++-------------
 gems/smithy/lib/smithy/welds/plugins.rb       |  2 +-
 projections/shapes/lib/shapes/client.rb       |  4 ++++
 projections/shapes/sig/shapes/client.rbs      |  1 +
 projections/weather/lib/weather/client.rb     |  4 ++++
 projections/weather/sig/weather/client.rbs    |  1 +
 7 files changed, 26 insertions(+), 20 deletions(-)

diff --git a/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb b/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
index 661fb5198..41578d69a 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
@@ -3,19 +3,22 @@
 module Smithy
   module Client
     module Plugins
+      # @api private
       class UserAgent < Plugin
-        option(:user_agent_suffix)
+        option(
+          :user_agent_suffix,
+          doc_type: String,
+          docstring: 'The suffix appended to the user agent string.'
+        )
 
+        # @api private
         class Handler < Client::Handler
           def call(context)
-            set_user_agent(context)
+            context.http_request.headers['User-Agent'] = UserAgent.new(context).to_s
             @handler.call(context)
           end
 
-          def set_user_agent(context)
-            context.http_request.headers['User-Agent'] = UserAgent.new(context)
-          end
-
+          # @api private
           class UserAgent
             def initialize(context)
               @context = context
diff --git a/gems/smithy-client/spec/smithy-client/plugins/user_agent_spec.rb b/gems/smithy-client/spec/smithy-client/plugins/user_agent_spec.rb
index 997fb5312..2efe720f7 100644
--- a/gems/smithy-client/spec/smithy-client/plugins/user_agent_spec.rb
+++ b/gems/smithy-client/spec/smithy-client/plugins/user_agent_spec.rb
@@ -8,17 +8,10 @@ module Smithy
   module Client
     module Plugins
       describe UserAgent do
-        let(:client_class) do
-          client_class = ClientHelper.sample_client.const_get(:Client)
-          client_class.clear_plugins
-          client_class.add_plugin(DummySendPlugin)
-          client_class.add_plugin(UserAgent)
-          client_class
-        end
-
-        let(:client) { client_class.new }
+        let(:client_class) { ClientHelper.sample_client.const_get(:Client) }
+        let(:client) { client_class.new(stub_responses: true) }
 
-        it 'adds user agent header to request' do
+        it 'adds a user agent header to request' do
           resp = client.operation
           ua_header = resp.context.http_request.headers['user-agent']
           expect(ua_header).to_not be_nil
@@ -27,8 +20,8 @@ module Plugins
           expect(ua_header).to include('ruby')
         end
 
-        it 'adds user agent suffix to user agent string when configured' do
-          client = client_class.new(user_agent_suffix: 'test-suffix')
+        it 'adds a user agent suffix to user agent string when configured' do
+          client = client_class.new(user_agent_suffix: 'test-suffix', stub_responses: true)
           resp = client.operation
           ua_header = resp.context.http_request.headers['user-agent']
           expect(ua_header).to end_with('test-suffix')
@@ -36,4 +29,4 @@ module Plugins
       end
     end
   end
-end
\ No newline at end of file
+end
diff --git a/gems/smithy/lib/smithy/welds/plugins.rb b/gems/smithy/lib/smithy/welds/plugins.rb
index ffc2cb583..f6e8c451c 100644
--- a/gems/smithy/lib/smithy/welds/plugins.rb
+++ b/gems/smithy/lib/smithy/welds/plugins.rb
@@ -28,7 +28,7 @@ def for?(_service)
         true
       end
 
-      def add_plugins
+      def add_plugins # rubocop:disable Metrics/MethodLength
         base_path = 'smithy-client/plugins'
         {
           Smithy::Client::Plugins::ChecksumRequired => { require_path: "#{base_path}/checksum_required" },
diff --git a/projections/shapes/lib/shapes/client.rb b/projections/shapes/lib/shapes/client.rb
index 6f518b2a5..0dd0b843f 100644
--- a/projections/shapes/lib/shapes/client.rb
+++ b/projections/shapes/lib/shapes/client.rb
@@ -20,6 +20,7 @@
 require 'smithy-client/plugins/response_target'
 require 'smithy-client/plugins/retry_errors'
 require 'smithy-client/plugins/stub_responses'
+require 'smithy-client/plugins/user_agent'
 
 module ShapeService
   # An API client for ShapeService.
@@ -47,6 +48,7 @@ class Client < Smithy::Client::Base
     add_plugin(Smithy::Client::Plugins::ResponseTarget)
     add_plugin(Smithy::Client::Plugins::RetryErrors)
     add_plugin(Smithy::Client::Plugins::StubResponses)
+    add_plugin(Smithy::Client::Plugins::UserAgent)
 
     # @param options [Hash] Client options
     # @option options [Boolean] :adaptive_retry_wait_to_fill (true)
@@ -158,6 +160,8 @@ class Client < Smithy::Client::Base
     #  By default fake responses are generated and returned. You can specify the response data
     #  to return or errors to raise by calling {Stubs#stub_responses}.
     #  @see Stubs
+    # @option options [String] :user_agent_suffix
+    #  The suffix appended to the user agent string.
     # @option options [Boolean] :validate_params (true)
     #  When `true`, request parameters are validated before sending the request.
     def initialize(*options)
diff --git a/projections/shapes/sig/shapes/client.rbs b/projections/shapes/sig/shapes/client.rbs
index 9fa100136..ec08f21b4 100644
--- a/projections/shapes/sig/shapes/client.rbs
+++ b/projections/shapes/sig/shapes/client.rbs
@@ -34,6 +34,7 @@ module ShapeService
       ?retry_max_attempts: Integer,
       ?retry_strategy: String | Class,
       ?stub_responses: bool,
+      ?user_agent_suffix: String,
       ?validate_params: bool,
     ) -> void | (?Hash[Symbol, untyped]) -> void
 
diff --git a/projections/weather/lib/weather/client.rb b/projections/weather/lib/weather/client.rb
index 231a2f2bc..ebedf0a50 100644
--- a/projections/weather/lib/weather/client.rb
+++ b/projections/weather/lib/weather/client.rb
@@ -20,6 +20,7 @@
 require 'smithy-client/plugins/response_target'
 require 'smithy-client/plugins/retry_errors'
 require 'smithy-client/plugins/stub_responses'
+require 'smithy-client/plugins/user_agent'
 
 module Weather
   # An API client for Weather.
@@ -47,6 +48,7 @@ class Client < Smithy::Client::Base
     add_plugin(Smithy::Client::Plugins::ResponseTarget)
     add_plugin(Smithy::Client::Plugins::RetryErrors)
     add_plugin(Smithy::Client::Plugins::StubResponses)
+    add_plugin(Smithy::Client::Plugins::UserAgent)
 
     # @param options [Hash] Client options
     # @option options [Boolean] :adaptive_retry_wait_to_fill (true)
@@ -158,6 +160,8 @@ class Client < Smithy::Client::Base
     #  By default fake responses are generated and returned. You can specify the response data
     #  to return or errors to raise by calling {Stubs#stub_responses}.
     #  @see Stubs
+    # @option options [String] :user_agent_suffix
+    #  The suffix appended to the user agent string.
     # @option options [Boolean] :validate_params (true)
     #  When `true`, request parameters are validated before sending the request.
     def initialize(*options)
diff --git a/projections/weather/sig/weather/client.rbs b/projections/weather/sig/weather/client.rbs
index 9dbfa5cec..79293ecdc 100644
--- a/projections/weather/sig/weather/client.rbs
+++ b/projections/weather/sig/weather/client.rbs
@@ -34,6 +34,7 @@ module Weather
       ?retry_max_attempts: Integer,
       ?retry_strategy: String | Class,
       ?stub_responses: bool,
+      ?user_agent_suffix: String,
       ?validate_params: bool,
     ) -> void | (?Hash[Symbol, untyped]) -> void
 

From 921460562b6fd819014f2334274d2728f817b1c7 Mon Sep 17 00:00:00 2001
From: Richard Wang <wangrch@amazon.com>
Date: Thu, 10 Jul 2025 09:54:34 -0700
Subject: [PATCH 07/13] Change doc type

---
 gems/smithy-client/lib/smithy-client/plugins/user_agent.rb      | 2 +-
 .../smithy-client/spec/smithy-client/plugins/user_agent_spec.rb | 2 --
 projections/shapes/lib/shapes/client.rb                         | 2 +-
 projections/shapes/sig/shapes/client.rbs                        | 2 +-
 projections/weather/lib/weather/client.rb                       | 2 +-
 projections/weather/sig/weather/client.rbs                      | 2 +-
 6 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb b/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
index 41578d69a..ed471f15e 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
@@ -7,7 +7,7 @@ module Plugins
       class UserAgent < Plugin
         option(
           :user_agent_suffix,
-          doc_type: String,
+          doc_type: 'header',
           docstring: 'The suffix appended to the user agent string.'
         )
 
diff --git a/gems/smithy-client/spec/smithy-client/plugins/user_agent_spec.rb b/gems/smithy-client/spec/smithy-client/plugins/user_agent_spec.rb
index 2efe720f7..c7d8db060 100644
--- a/gems/smithy-client/spec/smithy-client/plugins/user_agent_spec.rb
+++ b/gems/smithy-client/spec/smithy-client/plugins/user_agent_spec.rb
@@ -2,8 +2,6 @@
 
 require_relative '../../spec_helper'
 
-require 'smithy-client/plugins/user_agent'
-
 module Smithy
   module Client
     module Plugins
diff --git a/projections/shapes/lib/shapes/client.rb b/projections/shapes/lib/shapes/client.rb
index 0dd0b843f..b0c1bda67 100644
--- a/projections/shapes/lib/shapes/client.rb
+++ b/projections/shapes/lib/shapes/client.rb
@@ -160,7 +160,7 @@ class Client < Smithy::Client::Base
     #  By default fake responses are generated and returned. You can specify the response data
     #  to return or errors to raise by calling {Stubs#stub_responses}.
     #  @see Stubs
-    # @option options [String] :user_agent_suffix
+    # @option options [header] :user_agent_suffix
     #  The suffix appended to the user agent string.
     # @option options [Boolean] :validate_params (true)
     #  When `true`, request parameters are validated before sending the request.
diff --git a/projections/shapes/sig/shapes/client.rbs b/projections/shapes/sig/shapes/client.rbs
index ec08f21b4..0d477415b 100644
--- a/projections/shapes/sig/shapes/client.rbs
+++ b/projections/shapes/sig/shapes/client.rbs
@@ -34,7 +34,7 @@ module ShapeService
       ?retry_max_attempts: Integer,
       ?retry_strategy: String | Class,
       ?stub_responses: bool,
-      ?user_agent_suffix: String,
+      ?user_agent_suffix: header,
       ?validate_params: bool,
     ) -> void | (?Hash[Symbol, untyped]) -> void
 
diff --git a/projections/weather/lib/weather/client.rb b/projections/weather/lib/weather/client.rb
index ebedf0a50..01c2be082 100644
--- a/projections/weather/lib/weather/client.rb
+++ b/projections/weather/lib/weather/client.rb
@@ -160,7 +160,7 @@ class Client < Smithy::Client::Base
     #  By default fake responses are generated and returned. You can specify the response data
     #  to return or errors to raise by calling {Stubs#stub_responses}.
     #  @see Stubs
-    # @option options [String] :user_agent_suffix
+    # @option options [header] :user_agent_suffix
     #  The suffix appended to the user agent string.
     # @option options [Boolean] :validate_params (true)
     #  When `true`, request parameters are validated before sending the request.
diff --git a/projections/weather/sig/weather/client.rbs b/projections/weather/sig/weather/client.rbs
index 79293ecdc..1824fe2fe 100644
--- a/projections/weather/sig/weather/client.rbs
+++ b/projections/weather/sig/weather/client.rbs
@@ -34,7 +34,7 @@ module Weather
       ?retry_max_attempts: Integer,
       ?retry_strategy: String | Class,
       ?stub_responses: bool,
-      ?user_agent_suffix: String,
+      ?user_agent_suffix: header,
       ?validate_params: bool,
     ) -> void | (?Hash[Symbol, untyped]) -> void
 

From 2ac88b2d7dee6a972c7b9d36f81bb5eb3264a0e9 Mon Sep 17 00:00:00 2001
From: Richard Wang <wangrch@amazon.com>
Date: Thu, 10 Jul 2025 10:21:33 -0700
Subject: [PATCH 08/13] Fix docstring

---
 gems/smithy-client/lib/smithy-client/plugins/user_agent.rb | 4 ++--
 projections/shapes/lib/shapes/client.rb                    | 4 ++--
 projections/shapes/sig/shapes/client.rbs                   | 2 +-
 projections/weather/lib/weather/client.rb                  | 4 ++--
 projections/weather/sig/weather/client.rbs                 | 2 +-
 5 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb b/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
index ed471f15e..2b2c3cb4f 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
@@ -7,8 +7,8 @@ module Plugins
       class UserAgent < Plugin
         option(
           :user_agent_suffix,
-          doc_type: 'header',
-          docstring: 'The suffix appended to the user agent string.'
+          doc_type: String,
+          docstring: 'The suffix appended to the user agent header.'
         )
 
         # @api private
diff --git a/projections/shapes/lib/shapes/client.rb b/projections/shapes/lib/shapes/client.rb
index b0c1bda67..5470d5806 100644
--- a/projections/shapes/lib/shapes/client.rb
+++ b/projections/shapes/lib/shapes/client.rb
@@ -160,8 +160,8 @@ class Client < Smithy::Client::Base
     #  By default fake responses are generated and returned. You can specify the response data
     #  to return or errors to raise by calling {Stubs#stub_responses}.
     #  @see Stubs
-    # @option options [header] :user_agent_suffix
-    #  The suffix appended to the user agent string.
+    # @option options [String] :user_agent_suffix
+    #  The suffix appended to the user agent header.
     # @option options [Boolean] :validate_params (true)
     #  When `true`, request parameters are validated before sending the request.
     def initialize(*options)
diff --git a/projections/shapes/sig/shapes/client.rbs b/projections/shapes/sig/shapes/client.rbs
index 0d477415b..ec08f21b4 100644
--- a/projections/shapes/sig/shapes/client.rbs
+++ b/projections/shapes/sig/shapes/client.rbs
@@ -34,7 +34,7 @@ module ShapeService
       ?retry_max_attempts: Integer,
       ?retry_strategy: String | Class,
       ?stub_responses: bool,
-      ?user_agent_suffix: header,
+      ?user_agent_suffix: String,
       ?validate_params: bool,
     ) -> void | (?Hash[Symbol, untyped]) -> void
 
diff --git a/projections/weather/lib/weather/client.rb b/projections/weather/lib/weather/client.rb
index 01c2be082..7072043c0 100644
--- a/projections/weather/lib/weather/client.rb
+++ b/projections/weather/lib/weather/client.rb
@@ -160,8 +160,8 @@ class Client < Smithy::Client::Base
     #  By default fake responses are generated and returned. You can specify the response data
     #  to return or errors to raise by calling {Stubs#stub_responses}.
     #  @see Stubs
-    # @option options [header] :user_agent_suffix
-    #  The suffix appended to the user agent string.
+    # @option options [String] :user_agent_suffix
+    #  The suffix appended to the user agent header.
     # @option options [Boolean] :validate_params (true)
     #  When `true`, request parameters are validated before sending the request.
     def initialize(*options)
diff --git a/projections/weather/sig/weather/client.rbs b/projections/weather/sig/weather/client.rbs
index 1824fe2fe..79293ecdc 100644
--- a/projections/weather/sig/weather/client.rbs
+++ b/projections/weather/sig/weather/client.rbs
@@ -34,7 +34,7 @@ module Weather
       ?retry_max_attempts: Integer,
       ?retry_strategy: String | Class,
       ?stub_responses: bool,
-      ?user_agent_suffix: header,
+      ?user_agent_suffix: String,
       ?validate_params: bool,
     ) -> void | (?Hash[Symbol, untyped]) -> void
 

From d79939bf8e84bffb0fe6a6ba9feba6c8a2c90832 Mon Sep 17 00:00:00 2001
From: Richard Wang <wangrch@amazon.com>
Date: Thu, 10 Jul 2025 12:15:02 -0700
Subject: [PATCH 09/13] Update docstring

---
 gems/smithy-client/lib/smithy-client/plugins/user_agent.rb | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb b/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
index 2b2c3cb4f..d8779f650 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
@@ -8,8 +8,11 @@ class UserAgent < Plugin
         option(
           :user_agent_suffix,
           doc_type: String,
-          docstring: 'The suffix appended to the user agent header.'
-        )
+          docstring: <<~DOCS)
+            An optional string that is appended to the User-Agent header.
+            The default User-Agent includes the smithy-client version, 
+            the ruby platform and version, and host OS information.
+          DOCS
 
         # @api private
         class Handler < Client::Handler

From e5cb6ab5392bb99dbcdd1d246bee6936b647ca60 Mon Sep 17 00:00:00 2001
From: Richard Wang <wangrch@amazon.com>
Date: Thu, 10 Jul 2025 13:15:56 -0700
Subject: [PATCH 10/13] Add feature id tracking

---
 .../lib/smithy-client/pageable_response.rb           | 10 +++++++++-
 .../lib/smithy-client/waiters/poller.rb              | 12 +++++++++++-
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/gems/smithy-client/lib/smithy-client/pageable_response.rb b/gems/smithy-client/lib/smithy-client/pageable_response.rb
index 99b5e8844..f3f16b4dc 100644
--- a/gems/smithy-client/lib/smithy-client/pageable_response.rb
+++ b/gems/smithy-client/lib/smithy-client/pageable_response.rb
@@ -92,7 +92,7 @@ def next_page(params = {})
         raise LastPageError, self if last_page?
 
         params = next_page_params(params)
-        context.client.send(context.operation_name, params)
+        with_metric { context.client.send(context.operation_name, params) }
       end
 
       # Yields the current and each following response to the given block.
@@ -133,6 +133,14 @@ def next_page_params(params)
         new_params = context.params.except(*prev_tokens)
         new_params.merge!(@paginator.next_tokens(data).merge(params))
       end
+
+      def with_metric(&block)
+        Thread.current[:aws_sdk_core_user_agent_metric] ||= []
+        Thread.current[:aws_sdk_core_user_agent_metric] << 'C'
+        block.call
+      ensure
+        Thread.current[:aws_sdk_core_user_agent_metric].pop
+      end
     end
   end
 end
diff --git a/gems/smithy-client/lib/smithy-client/waiters/poller.rb b/gems/smithy-client/lib/smithy-client/waiters/poller.rb
index 3fdd25649..18842af35 100644
--- a/gems/smithy-client/lib/smithy-client/waiters/poller.rb
+++ b/gems/smithy-client/lib/smithy-client/waiters/poller.rb
@@ -15,7 +15,9 @@ def call(client, params)
           @input = params
           request = client.build_request(@operation_name, params)
           request.handlers.remove(Plugins::RaiseResponseErrors::Handler)
-          response = request.send_request
+          response = with_metric do
+            request.send_request
+          end
           status = evaluate_acceptors(response)
           [response, status.to_sym]
         end
@@ -87,6 +89,14 @@ def anyStringEquals?(actual, expected)
           actual.any? { |value| value == expected }
         end
         # rubocop:enable Naming/MethodName
+
+        def with_metric(&block)
+          Thread.current[:aws_sdk_core_user_agent_metric] ||= []
+          Thread.current[:aws_sdk_core_user_agent_metric] << 'B'
+          block.call
+        ensure
+          Thread.current[:aws_sdk_core_user_agent_metric].pop
+        end
       end
     end
   end

From 2277c362fb50a3fe7ad5abdf36ad52209ab91b75 Mon Sep 17 00:00:00 2001
From: Richard Wang <wangrch@amazon.com>
Date: Thu, 10 Jul 2025 13:18:44 -0700
Subject: [PATCH 11/13] Regenerate projections

---
 projections/shapes/lib/shapes/client.rb   | 4 +++-
 projections/weather/lib/weather/client.rb | 4 +++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/projections/shapes/lib/shapes/client.rb b/projections/shapes/lib/shapes/client.rb
index 5470d5806..889aef27e 100644
--- a/projections/shapes/lib/shapes/client.rb
+++ b/projections/shapes/lib/shapes/client.rb
@@ -161,7 +161,9 @@ class Client < Smithy::Client::Base
     #  to return or errors to raise by calling {Stubs#stub_responses}.
     #  @see Stubs
     # @option options [String] :user_agent_suffix
-    #  The suffix appended to the user agent header.
+    #  An optional string that is appended to the User-Agent header.
+    #  The default User-Agent includes the smithy-client version, 
+    #  the ruby platform and version, and host OS information.
     # @option options [Boolean] :validate_params (true)
     #  When `true`, request parameters are validated before sending the request.
     def initialize(*options)
diff --git a/projections/weather/lib/weather/client.rb b/projections/weather/lib/weather/client.rb
index 7072043c0..9dbe1532e 100644
--- a/projections/weather/lib/weather/client.rb
+++ b/projections/weather/lib/weather/client.rb
@@ -161,7 +161,9 @@ class Client < Smithy::Client::Base
     #  to return or errors to raise by calling {Stubs#stub_responses}.
     #  @see Stubs
     # @option options [String] :user_agent_suffix
-    #  The suffix appended to the user agent header.
+    #  An optional string that is appended to the User-Agent header.
+    #  The default User-Agent includes the smithy-client version, 
+    #  the ruby platform and version, and host OS information.
     # @option options [Boolean] :validate_params (true)
     #  When `true`, request parameters are validated before sending the request.
     def initialize(*options)

From 130930adca411e828b6b8b72a37c36147cd56d26 Mon Sep 17 00:00:00 2001
From: Richard Wang <wangrch@amazon.com>
Date: Thu, 10 Jul 2025 13:30:39 -0700
Subject: [PATCH 12/13] Rubocop

---
 gems/smithy-client/lib/smithy-client/plugins/user_agent.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb b/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
index d8779f650..683c671e4 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/user_agent.rb
@@ -10,7 +10,7 @@ class UserAgent < Plugin
           doc_type: String,
           docstring: <<~DOCS)
             An optional string that is appended to the User-Agent header.
-            The default User-Agent includes the smithy-client version, 
+            The default User-Agent includes the smithy-client version,
             the ruby platform and version, and host OS information.
           DOCS
 

From 92431f87fbe7dc187e4689ed204a7017716cf9f9 Mon Sep 17 00:00:00 2001
From: Richard Wang <wangrch@amazon.com>
Date: Thu, 10 Jul 2025 13:56:25 -0700
Subject: [PATCH 13/13] Revert with_metrics

---
 .../lib/smithy-client/pageable_response.rb           | 10 +---------
 .../lib/smithy-client/waiters/poller.rb              | 12 +-----------
 projections/shapes/lib/shapes/client.rb              |  2 +-
 projections/weather/lib/weather/client.rb            |  2 +-
 4 files changed, 4 insertions(+), 22 deletions(-)

diff --git a/gems/smithy-client/lib/smithy-client/pageable_response.rb b/gems/smithy-client/lib/smithy-client/pageable_response.rb
index f3f16b4dc..99b5e8844 100644
--- a/gems/smithy-client/lib/smithy-client/pageable_response.rb
+++ b/gems/smithy-client/lib/smithy-client/pageable_response.rb
@@ -92,7 +92,7 @@ def next_page(params = {})
         raise LastPageError, self if last_page?
 
         params = next_page_params(params)
-        with_metric { context.client.send(context.operation_name, params) }
+        context.client.send(context.operation_name, params)
       end
 
       # Yields the current and each following response to the given block.
@@ -133,14 +133,6 @@ def next_page_params(params)
         new_params = context.params.except(*prev_tokens)
         new_params.merge!(@paginator.next_tokens(data).merge(params))
       end
-
-      def with_metric(&block)
-        Thread.current[:aws_sdk_core_user_agent_metric] ||= []
-        Thread.current[:aws_sdk_core_user_agent_metric] << 'C'
-        block.call
-      ensure
-        Thread.current[:aws_sdk_core_user_agent_metric].pop
-      end
     end
   end
 end
diff --git a/gems/smithy-client/lib/smithy-client/waiters/poller.rb b/gems/smithy-client/lib/smithy-client/waiters/poller.rb
index 18842af35..3fdd25649 100644
--- a/gems/smithy-client/lib/smithy-client/waiters/poller.rb
+++ b/gems/smithy-client/lib/smithy-client/waiters/poller.rb
@@ -15,9 +15,7 @@ def call(client, params)
           @input = params
           request = client.build_request(@operation_name, params)
           request.handlers.remove(Plugins::RaiseResponseErrors::Handler)
-          response = with_metric do
-            request.send_request
-          end
+          response = request.send_request
           status = evaluate_acceptors(response)
           [response, status.to_sym]
         end
@@ -89,14 +87,6 @@ def anyStringEquals?(actual, expected)
           actual.any? { |value| value == expected }
         end
         # rubocop:enable Naming/MethodName
-
-        def with_metric(&block)
-          Thread.current[:aws_sdk_core_user_agent_metric] ||= []
-          Thread.current[:aws_sdk_core_user_agent_metric] << 'B'
-          block.call
-        ensure
-          Thread.current[:aws_sdk_core_user_agent_metric].pop
-        end
       end
     end
   end
diff --git a/projections/shapes/lib/shapes/client.rb b/projections/shapes/lib/shapes/client.rb
index 889aef27e..13d353430 100644
--- a/projections/shapes/lib/shapes/client.rb
+++ b/projections/shapes/lib/shapes/client.rb
@@ -162,7 +162,7 @@ class Client < Smithy::Client::Base
     #  @see Stubs
     # @option options [String] :user_agent_suffix
     #  An optional string that is appended to the User-Agent header.
-    #  The default User-Agent includes the smithy-client version, 
+    #  The default User-Agent includes the smithy-client version,
     #  the ruby platform and version, and host OS information.
     # @option options [Boolean] :validate_params (true)
     #  When `true`, request parameters are validated before sending the request.
diff --git a/projections/weather/lib/weather/client.rb b/projections/weather/lib/weather/client.rb
index 9dbe1532e..b2d2c06a4 100644
--- a/projections/weather/lib/weather/client.rb
+++ b/projections/weather/lib/weather/client.rb
@@ -162,7 +162,7 @@ class Client < Smithy::Client::Base
     #  @see Stubs
     # @option options [String] :user_agent_suffix
     #  An optional string that is appended to the User-Agent header.
-    #  The default User-Agent includes the smithy-client version, 
+    #  The default User-Agent includes the smithy-client version,
     #  the ruby platform and version, and host OS information.
     # @option options [Boolean] :validate_params (true)
     #  When `true`, request parameters are validated before sending the request.