diff --git a/codegen/projections/rails_json/lib/rails_json/auth.rb b/codegen/projections/rails_json/lib/rails_json/auth.rb
index da65bad8a..63edb7f96 100644
--- a/codegen/projections/rails_json/lib/rails_json/auth.rb
+++ b/codegen/projections/rails_json/lib/rails_json/auth.rb
@@ -9,7 +9,13 @@
 
 module RailsJson
   module Auth
-    Params = Struct.new(:operation_name, keyword_init: true)
+    class Params
+      def initialize(operation_name: nil)
+        @operation_name = operation_name
+      end
+
+      attr_accessor :operation_name
+    end
 
     SCHEMES = [
       Hearth::AuthSchemes::Anonymous.new
diff --git a/codegen/projections/rails_json/lib/rails_json/config.rb b/codegen/projections/rails_json/lib/rails_json/config.rb
index 23583ac59..2a06bb5d6 100644
--- a/codegen/projections/rails_json/lib/rails_json/config.rb
+++ b/codegen/projections/rails_json/lib/rails_json/config.rb
@@ -91,26 +91,29 @@ module RailsJson
   #   @return [Hearth::Stubs]
   # @!attribute validate_input
   #   @return [Boolean]
-  Config = ::Struct.new(
-    :auth_resolver,
-    :auth_schemes,
-    :disable_host_prefix,
-    :disable_request_compression,
-    :endpoint,
-    :endpoint_resolver,
-    :http_client,
-    :interceptors,
-    :logger,
-    :plugins,
-    :request_min_compression_size_bytes,
-    :retry_strategy,
-    :stub_responses,
-    :stubs,
-    :validate_input,
-    keyword_init: true
-  ) do
+  class Config
     include Hearth::Configuration
 
+    MEMBERS = %i[
+      auth_resolver
+      auth_schemes
+      disable_host_prefix
+      disable_request_compression
+      endpoint
+      endpoint_resolver
+      http_client
+      interceptors
+      logger
+      plugins
+      request_min_compression_size_bytes
+      retry_strategy
+      stub_responses
+      stubs
+      validate_input
+    ].freeze
+
+    attr_accessor(*MEMBERS)
+
     # Validates the configuration.
     def validate!
       Hearth::Validator.validate_responds_to!(auth_resolver, :resolve, context: 'config[:auth_resolver]')
diff --git a/codegen/projections/rails_json/lib/rails_json/endpoint.rb b/codegen/projections/rails_json/lib/rails_json/endpoint.rb
index 378dbea6b..30bcee06e 100644
--- a/codegen/projections/rails_json/lib/rails_json/endpoint.rb
+++ b/codegen/projections/rails_json/lib/rails_json/endpoint.rb
@@ -9,11 +9,12 @@
 
 module RailsJson
   module Endpoint
-    Params = ::Struct.new(
-      :endpoint,
-      keyword_init: true
-    ) do
-      include Hearth::Structure
+    class Params
+      def initialize(endpoint: nil)
+        @endpoint = endpoint
+      end
+
+      attr_accessor :endpoint
     end
 
     class Resolver
diff --git a/codegen/projections/rails_json/lib/rails_json/plugins/global_config.rb b/codegen/projections/rails_json/lib/rails_json/plugins/global_config.rb
index 8114b8745..fa257f629 100644
--- a/codegen/projections/rails_json/lib/rails_json/plugins/global_config.rb
+++ b/codegen/projections/rails_json/lib/rails_json/plugins/global_config.rb
@@ -17,7 +17,7 @@ class GlobalConfig
       def call(config)
         options = config.options
         ::Hearth.config.each do |key, value|
-          config[key] = value unless options.key?(key)
+          config.send("#{key}=", value) unless options.key?(key)
         end
       end
 
diff --git a/codegen/projections/rails_json/lib/rails_json/types.rb b/codegen/projections/rails_json/lib/rails_json/types.rb
index e2e0f443e..c3f783dc7 100644
--- a/codegen/projections/rails_json/lib/rails_json/types.rb
+++ b/codegen/projections/rails_json/lib/rails_json/types.rb
@@ -1925,50 +1925,30 @@ class StringValue < MyUnion
         def to_h
           { string_value: super(__getobj__) }
         end
-
-        def to_s
-          "#<RailsJson::Types::StringValue #{__getobj__ || 'nil'}>"
-        end
       end
 
       class BooleanValue < MyUnion
         def to_h
           { boolean_value: super(__getobj__) }
         end
-
-        def to_s
-          "#<RailsJson::Types::BooleanValue #{__getobj__ || 'nil'}>"
-        end
       end
 
       class NumberValue < MyUnion
         def to_h
           { number_value: super(__getobj__) }
         end
-
-        def to_s
-          "#<RailsJson::Types::NumberValue #{__getobj__ || 'nil'}>"
-        end
       end
 
       class BlobValue < MyUnion
         def to_h
           { blob_value: super(__getobj__) }
         end
-
-        def to_s
-          "#<RailsJson::Types::BlobValue #{__getobj__ || 'nil'}>"
-        end
       end
 
       class TimestampValue < MyUnion
         def to_h
           { timestamp_value: super(__getobj__) }
         end
-
-        def to_s
-          "#<RailsJson::Types::TimestampValue #{__getobj__ || 'nil'}>"
-        end
       end
 
       # Enum, one of: ["Foo", "Baz", "Bar", "1", "0"]
@@ -1976,50 +1956,30 @@ class EnumValue < MyUnion
         def to_h
           { enum_value: super(__getobj__) }
         end
-
-        def to_s
-          "#<RailsJson::Types::EnumValue #{__getobj__ || 'nil'}>"
-        end
       end
 
       class ListValue < MyUnion
         def to_h
           { list_value: super(__getobj__) }
         end
-
-        def to_s
-          "#<RailsJson::Types::ListValue #{__getobj__ || 'nil'}>"
-        end
       end
 
       class MapValue < MyUnion
         def to_h
           { map_value: super(__getobj__) }
         end
-
-        def to_s
-          "#<RailsJson::Types::MapValue #{__getobj__ || 'nil'}>"
-        end
       end
 
       class StructureValue < MyUnion
         def to_h
           { structure_value: super(__getobj__) }
         end
-
-        def to_s
-          "#<RailsJson::Types::StructureValue #{__getobj__ || 'nil'}>"
-        end
       end
 
       class RenamedStructureValue < MyUnion
         def to_h
           { renamed_structure_value: super(__getobj__) }
         end
-
-        def to_s
-          "#<RailsJson::Types::RenamedStructureValue #{__getobj__ || 'nil'}>"
-        end
       end
 
       class Unknown < MyUnion
@@ -2519,10 +2479,6 @@ class Quit < PlayerAction
         def to_h
           { quit: super(__getobj__) }
         end
-
-        def to_s
-          "#<RailsJson::Types::Quit #{__getobj__ || 'nil'}>"
-        end
       end
 
       class Unknown < PlayerAction
@@ -3424,10 +3380,6 @@ class Greeting < UnionPayload
         def to_h
           { greeting: super(__getobj__) }
         end
-
-        def to_s
-          "#<RailsJson::Types::Greeting #{__getobj__ || 'nil'}>"
-        end
       end
 
       class Unknown < UnionPayload
@@ -3450,30 +3402,18 @@ class Foo < UnionWithJsonName
         def to_h
           { foo: super(__getobj__) }
         end
-
-        def to_s
-          "#<RailsJson::Types::Foo #{__getobj__ || 'nil'}>"
-        end
       end
 
       class Bar < UnionWithJsonName
         def to_h
           { bar: super(__getobj__) }
         end
-
-        def to_s
-          "#<RailsJson::Types::Bar #{__getobj__ || 'nil'}>"
-        end
       end
 
       class Baz < UnionWithJsonName
         def to_h
           { baz: super(__getobj__) }
         end
-
-        def to_s
-          "#<RailsJson::Types::Baz #{__getobj__ || 'nil'}>"
-        end
       end
 
       class Unknown < UnionWithJsonName
diff --git a/codegen/projections/rails_json/sig/rails_json/auth.rbs b/codegen/projections/rails_json/sig/rails_json/auth.rbs
index cc320c39f..da5377dae 100644
--- a/codegen/projections/rails_json/sig/rails_json/auth.rbs
+++ b/codegen/projections/rails_json/sig/rails_json/auth.rbs
@@ -9,7 +9,8 @@
 
 module RailsJson
   module Auth
-    class Params < ::Struct[untyped]
+    class Params
+      def initialize: (?operation_name: ::Symbol?) -> void
       attr_accessor operation_name (): ::Symbol
     end
 
diff --git a/codegen/projections/rails_json/sig/rails_json/config.rbs b/codegen/projections/rails_json/sig/rails_json/config.rbs
index 4637ef242..ef2d8eaa1 100644
--- a/codegen/projections/rails_json/sig/rails_json/config.rbs
+++ b/codegen/projections/rails_json/sig/rails_json/config.rbs
@@ -1,22 +1,21 @@
 module RailsJson
-  class Config < ::Struct[untyped]
+  class Config
     include Hearth::Configuration[instance]
-
-    attr_accessor auth_resolver (): Hearth::_AuthResolver[Auth::Params]
-    attr_accessor auth_schemes (): Array[Hearth::AuthSchemes::Base]
-    attr_accessor disable_host_prefix (): bool
-    attr_accessor disable_request_compression (): bool
-    attr_accessor endpoint (): String
-    attr_accessor endpoint_resolver (): Hearth::_EndpointResolver[Endpoint::Params]
-    attr_accessor http_client (): Hearth::HTTP::Client
-    attr_accessor interceptors (): Hearth::InterceptorList[Config]
-    attr_accessor logger (): Logger
-    attr_accessor plugins (): Hearth::PluginList[Config]
-    attr_accessor request_min_compression_size_bytes (): Integer
-    attr_accessor retry_strategy (): Hearth::_RetryStrategy
-    attr_accessor stub_responses (): bool
-    attr_accessor stubs (): Hearth::Stubs
-    attr_accessor validate_input (): bool
+    attr_accessor auth_resolver (): Hearth::_AuthResolver[Auth::Params]?
+    attr_accessor auth_schemes (): Array[Hearth::AuthSchemes::Base]?
+    attr_accessor disable_host_prefix (): bool?
+    attr_accessor disable_request_compression (): bool?
+    attr_accessor endpoint (): String?
+    attr_accessor endpoint_resolver (): Hearth::_EndpointResolver[Endpoint::Params]?
+    attr_accessor http_client (): Hearth::HTTP::Client?
+    attr_accessor interceptors (): Hearth::InterceptorList[Config]?
+    attr_accessor logger (): Logger?
+    attr_accessor plugins (): Hearth::PluginList[Config]?
+    attr_accessor request_min_compression_size_bytes (): Integer?
+    attr_accessor retry_strategy (): Hearth::_RetryStrategy?
+    attr_accessor stub_responses (): bool?
+    attr_accessor stubs (): Hearth::Stubs?
+    attr_accessor validate_input (): bool?
 
     def validate!: () -> void
   end
diff --git a/codegen/projections/rails_json/sig/rails_json/endpoint.rbs b/codegen/projections/rails_json/sig/rails_json/endpoint.rbs
index 85ca39059..5894355ce 100644
--- a/codegen/projections/rails_json/sig/rails_json/endpoint.rbs
+++ b/codegen/projections/rails_json/sig/rails_json/endpoint.rbs
@@ -9,8 +9,9 @@
 
 module RailsJson
   module Endpoint
-    class Params < ::Struct[untyped]
-      attr_accessor endpoint: ::String
+    class Params
+      def initialize: (?endpoint: ::String?) -> void
+      attr_accessor endpoint (): ::String?
     end
 
     class Resolver
diff --git a/codegen/projections/rails_json/sig/rails_json/types.rbs b/codegen/projections/rails_json/sig/rails_json/types.rbs
index 62d9fee19..9174074ce 100644
--- a/codegen/projections/rails_json/sig/rails_json/types.rbs
+++ b/codegen/projections/rails_json/sig/rails_json/types.rbs
@@ -68,7 +68,7 @@ module RailsJson
 
     class ConstantQueryStringInput
       include Hearth::Structure
-      attr_accessor hello (): ::String
+      attr_accessor hello (): ::String?
     end
 
     class ConstantQueryStringOutput
@@ -173,7 +173,7 @@ module RailsJson
 
     class EndpointWithHostLabelOperationInput
       include Hearth::Structure
-      attr_accessor label (): ::String
+      attr_accessor label (): ::String?
     end
 
     class EndpointWithHostLabelOperationOutput
@@ -315,8 +315,8 @@ module RailsJson
 
     class HttpRequestWithFloatLabelsInput
       include Hearth::Structure
-      attr_accessor float (): ::Float
-      attr_accessor double (): ::Float
+      attr_accessor float (): ::Float?
+      attr_accessor double (): ::Float?
     end
 
     class HttpRequestWithFloatLabelsOutput
@@ -325,8 +325,8 @@ module RailsJson
 
     class HttpRequestWithGreedyLabelInPathInput
       include Hearth::Structure
-      attr_accessor foo (): ::String
-      attr_accessor baz (): ::String
+      attr_accessor foo (): ::String?
+      attr_accessor baz (): ::String?
     end
 
     class HttpRequestWithGreedyLabelInPathOutput
@@ -335,13 +335,13 @@ module RailsJson
 
     class HttpRequestWithLabelsAndTimestampFormatInput
       include Hearth::Structure
-      attr_accessor member_epoch_seconds (): ::Time
-      attr_accessor member_http_date (): ::Time
-      attr_accessor member_date_time (): ::Time
-      attr_accessor default_format (): ::Time
-      attr_accessor target_epoch_seconds (): ::Time
-      attr_accessor target_http_date (): ::Time
-      attr_accessor target_date_time (): ::Time
+      attr_accessor member_epoch_seconds (): ::Time?
+      attr_accessor member_http_date (): ::Time?
+      attr_accessor member_date_time (): ::Time?
+      attr_accessor default_format (): ::Time?
+      attr_accessor target_epoch_seconds (): ::Time?
+      attr_accessor target_http_date (): ::Time?
+      attr_accessor target_date_time (): ::Time?
     end
 
     class HttpRequestWithLabelsAndTimestampFormatOutput
@@ -350,14 +350,14 @@ module RailsJson
 
     class HttpRequestWithLabelsInput
       include Hearth::Structure
-      attr_accessor string (): ::String
-      attr_accessor short (): ::Integer
-      attr_accessor integer (): ::Integer
-      attr_accessor long (): ::Integer
-      attr_accessor float (): ::Float
-      attr_accessor double (): ::Float
-      attr_accessor boolean (): bool
-      attr_accessor timestamp (): ::Time
+      attr_accessor string (): ::String?
+      attr_accessor short (): ::Integer?
+      attr_accessor integer (): ::Integer?
+      attr_accessor long (): ::Integer?
+      attr_accessor float (): ::Float?
+      attr_accessor double (): ::Float?
+      attr_accessor boolean (): bool?
+      attr_accessor timestamp (): ::Time?
     end
 
     class HttpRequestWithLabelsOutput
@@ -366,7 +366,7 @@ module RailsJson
 
     class HttpRequestWithRegexLiteralInput
       include Hearth::Structure
-      attr_accessor str (): ::String
+      attr_accessor str (): ::String?
     end
 
     class HttpRequestWithRegexLiteralOutput
@@ -768,12 +768,12 @@ module RailsJson
 
     class OperationWithNestedStructureInput
       include Hearth::Structure
-      attr_accessor top_level (): Types::TopLevel
+      attr_accessor top_level (): Types::TopLevel?
     end
 
     class OperationWithNestedStructureOutput
       include Hearth::Structure
-      attr_accessor dialog (): Types::Dialog
+      attr_accessor dialog (): Types::Dialog?
       attr_accessor dialog_list (): ::Array[Types::Dialog]?
       attr_accessor dialog_map (): ::Hash[::String, Types::Dialog]?
     end
@@ -802,7 +802,7 @@ module RailsJson
 
     class PostPlayerActionOutput
       include Hearth::Structure
-      attr_accessor action (): Types::PlayerAction
+      attr_accessor action (): Types::PlayerAction?
     end
 
     class PostUnionWithJsonNameInput
@@ -812,7 +812,7 @@ module RailsJson
 
     class PostUnionWithJsonNameOutput
       include Hearth::Structure
-      attr_accessor value (): Types::UnionWithJsonName
+      attr_accessor value (): Types::UnionWithJsonName?
     end
 
     class PutWithContentEncodingInput
@@ -1070,7 +1070,7 @@ module RailsJson
 
     class TopLevel
       include Hearth::Structure
-      attr_accessor dialog (): Types::Dialog
+      attr_accessor dialog (): Types::Dialog?
       attr_accessor dialog_list (): ::Array[Types::Dialog]?
       attr_accessor dialog_map (): ::Hash[::String, Types::Dialog]?
     end
diff --git a/codegen/projections/rails_json/spec/protocol_spec.rb b/codegen/projections/rails_json/spec/protocol_spec.rb
index 91bc08244..929b62dcd 100644
--- a/codegen/projections/rails_json/spec/protocol_spec.rb
+++ b/codegen/projections/rails_json/spec/protocol_spec.rb
@@ -478,7 +478,7 @@ module RailsJson
       describe 'stubs' do
 
         # Ensures that clients can correctly parse datetime (timestamps) with offsets
-        it 'stubs RailsJsonDateTimeWithNegativeOffset' do
+        it 'RailsJsonDateTimeWithNegativeOffset' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -494,7 +494,7 @@ module RailsJson
         end
 
         # Ensures that clients can correctly parse datetime (timestamps) with offsets
-        it 'stubs RailsJsonDateTimeWithPositiveOffset' do
+        it 'RailsJsonDateTimeWithPositiveOffset' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -743,7 +743,7 @@ module RailsJson
       describe 'stubs' do
 
         # Serializes documents as part of the JSON response payload with no escaping.
-        it 'stubs RailsJsonDocumentOutput' do
+        it 'RailsJsonDocumentOutput' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -761,7 +761,7 @@ module RailsJson
         end
 
         # Document types can be JSON scalars too.
-        it 'stubs RailsJsonDocumentOutputString' do
+        it 'RailsJsonDocumentOutputString' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -779,7 +779,7 @@ module RailsJson
         end
 
         # Document types can be JSON scalars too.
-        it 'stubs RailsJsonDocumentOutputNumber' do
+        it 'RailsJsonDocumentOutputNumber' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -797,7 +797,7 @@ module RailsJson
         end
 
         # Document types can be JSON scalars too.
-        it 'stubs RailsJsonDocumentOutputBoolean' do
+        it 'RailsJsonDocumentOutputBoolean' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -815,7 +815,7 @@ module RailsJson
         end
 
         # Document types can be JSON arrays.
-        it 'stubs RailsJsonDocumentOutputArray' do
+        it 'RailsJsonDocumentOutputArray' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -900,7 +900,7 @@ module RailsJson
       describe 'stubs' do
 
         # Serializes a map that uses documents as the value.
-        it 'stubs RailsJsonDocumentTypeAsMapValueOutput' do
+        it 'RailsJsonDocumentTypeAsMapValueOutput' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -1006,7 +1006,7 @@ module RailsJson
       describe 'stubs' do
 
         # Serializes a document as the target of the httpPayload trait.
-        it 'stubs RailsJsonDocumentTypeAsPayloadOutput' do
+        it 'RailsJsonDocumentTypeAsPayloadOutput' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -1022,7 +1022,7 @@ module RailsJson
         end
 
         # Serializes a document as a payload string.
-        it 'stubs RailsJsonDocumentTypeAsPayloadOutputString' do
+        it 'RailsJsonDocumentTypeAsPayloadOutputString' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -1099,7 +1099,7 @@ module RailsJson
         # As of January 2021, server implementations are expected to
         # respond with a JSON object regardless of if the output
         # parameters are empty.
-        it 'stubs RailsJsonEmptyInputAndEmptyOutput' do
+        it 'RailsJsonEmptyInputAndEmptyOutput' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -1112,7 +1112,7 @@ module RailsJson
 
         # This test ensures that clients can gracefully handle
         # situations where a service omits a JSON payload entirely.
-        it 'stubs RailsJsonEmptyInputAndEmptyOutputJsonObjectOutput' do
+        it 'RailsJsonEmptyInputAndEmptyOutputJsonObjectOutput' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -1204,7 +1204,7 @@ module RailsJson
       describe 'stubs' do
 
         # Ensures that clients can correctly parse datetime timestamps with fractional seconds
-        it 'stubs RailsJsonDateTimeWithFractionalSeconds' do
+        it 'RailsJsonDateTimeWithFractionalSeconds' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -1272,7 +1272,7 @@ module RailsJson
         # server implementations are expected to respond with a
         # JSON object regardless of if the output parameters are
         # empty.
-        it 'stubs RailsJsonGreetingWithErrors' do
+        it 'RailsJsonGreetingWithErrors' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -1290,7 +1290,7 @@ module RailsJson
         # This test is similar to RailsJsonGreetingWithErrors, but it
         # ensures that clients can gracefully deal with a server
         # omitting a response payload.
-        it 'stubs RailsJsonGreetingWithErrorsNoPayload' do
+        it 'RailsJsonGreetingWithErrorsNoPayload' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -1525,7 +1525,7 @@ module RailsJson
       describe 'stubs' do
 
         #
-        it 'stubs RailsJsonEnumPayloadResponse' do
+        it 'RailsJsonEnumPayloadResponse' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -1622,7 +1622,7 @@ module RailsJson
       describe 'stubs' do
 
         # Serializes a blob in the HTTP payload
-        it 'stubs RailsJsonHttpPayloadTraitsWithBlob' do
+        it 'RailsJsonHttpPayloadTraitsWithBlob' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -1640,7 +1640,7 @@ module RailsJson
         end
 
         # Serializes an empty blob in the HTTP payload
-        it 'stubs RailsJsonHttpPayloadTraitsWithNoBlobBody' do
+        it 'RailsJsonHttpPayloadTraitsWithNoBlobBody' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -1707,7 +1707,7 @@ module RailsJson
       describe 'stubs' do
 
         # Serializes a blob in the HTTP payload with a content-type
-        it 'stubs RailsJsonHttpPayloadTraitsWithMediaTypeWithBlob' do
+        it 'RailsJsonHttpPayloadTraitsWithMediaTypeWithBlob' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -1785,7 +1785,7 @@ module RailsJson
       describe 'stubs' do
 
         # Serializes a structure in the payload
-        it 'stubs RailsJsonHttpPayloadWithStructure' do
+        it 'RailsJsonHttpPayloadWithStructure' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -1889,7 +1889,7 @@ module RailsJson
       describe 'stubs' do
 
         # Serializes a union in the payload.
-        it 'stubs RailsJsonHttpPayloadWithUnion' do
+        it 'RailsJsonHttpPayloadWithUnion' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -1909,7 +1909,7 @@ module RailsJson
         end
 
         # No payload is sent if the union has no value.
-        it 'stubs RailsJsonHttpPayloadWithUnsetUnion' do
+        it 'RailsJsonHttpPayloadWithUnsetUnion' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -1995,7 +1995,7 @@ module RailsJson
       describe 'stubs' do
 
         # Adds headers by prefix
-        it 'stubs RailsJsonHttpPrefixHeadersArePresent' do
+        it 'RailsJsonHttpPrefixHeadersArePresent' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -2048,7 +2048,7 @@ module RailsJson
       describe 'stubs' do
 
         # (de)serializes all response headers
-        it 'stubs RailsJsonHttpPrefixHeadersResponse' do
+        it 'RailsJsonHttpPrefixHeadersResponse' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -2305,7 +2305,7 @@ module RailsJson
         # empty JSON object is serialized in the response. However,
         # clients should be able to handle an empty JSON object or an
         # empty payload without failing to deserialize a response.
-        it 'stubs RailsJsonHttpResponseCode' do
+        it 'RailsJsonHttpResponseCode' do
           proc = proc do |context|
             expect(context.response.status).to eq(201)
           end
@@ -2323,7 +2323,7 @@ module RailsJson
         # This test ensures that clients gracefully handle cases where
         # the service responds with no payload rather than an empty JSON
         # object.
-        it 'stubs RailsJsonHttpResponseCodeWithNoPayload' do
+        it 'RailsJsonHttpResponseCodeWithNoPayload' do
           proc = proc do |context|
             expect(context.response.status).to eq(201)
           end
@@ -2384,7 +2384,7 @@ module RailsJson
       describe 'stubs' do
 
         #
-        it 'stubs RailsJsonStringPayloadResponse' do
+        it 'RailsJsonStringPayloadResponse' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -2445,7 +2445,7 @@ module RailsJson
         # of an operation. As of January 2021, server implementations
         # are expected to respond with a JSON object regardless of
         # if the output parameters are empty.
-        it 'stubs RailsJsonIgnoreQueryParamsInResponse' do
+        it 'RailsJsonIgnoreQueryParamsInResponse' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -2459,7 +2459,7 @@ module RailsJson
         # This test is similar to RailsJsonIgnoreQueryParamsInResponse,
         # but it ensures that clients gracefully handle responses from
         # the server that do not serialize an empty JSON object.
-        it 'stubs RailsJsonIgnoreQueryParamsInResponseNoPayload' do
+        it 'RailsJsonIgnoreQueryParamsInResponseNoPayload' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -2884,7 +2884,7 @@ module RailsJson
       describe 'stubs' do
 
         # Tests responses with string header bindings
-        it 'stubs RailsJsonInputAndOutputWithStringHeaders' do
+        it 'RailsJsonInputAndOutputWithStringHeaders' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -2920,7 +2920,7 @@ module RailsJson
         end
 
         # Tests responses with string list header bindings that require quoting
-        it 'stubs RailsJsonInputAndOutputWithQuotedStringHeaders' do
+        it 'RailsJsonInputAndOutputWithQuotedStringHeaders' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -2944,7 +2944,7 @@ module RailsJson
         end
 
         # Tests responses with numeric header bindings
-        it 'stubs RailsJsonInputAndOutputWithNumericHeaders' do
+        it 'RailsJsonInputAndOutputWithNumericHeaders' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -2980,7 +2980,7 @@ module RailsJson
         end
 
         # Tests responses with boolean header bindings
-        it 'stubs RailsJsonInputAndOutputWithBooleanHeaders' do
+        it 'RailsJsonInputAndOutputWithBooleanHeaders' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -3008,7 +3008,7 @@ module RailsJson
         end
 
         # Tests responses with timestamp header bindings
-        it 'stubs RailsJsonInputAndOutputWithTimestampHeaders' do
+        it 'RailsJsonInputAndOutputWithTimestampHeaders' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -3030,7 +3030,7 @@ module RailsJson
         end
 
         # Tests responses with enum header bindings
-        it 'stubs RailsJsonInputAndOutputWithEnumHeaders' do
+        it 'RailsJsonInputAndOutputWithEnumHeaders' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -3056,7 +3056,7 @@ module RailsJson
         end
 
         # Tests responses with intEnum header bindings
-        it 'stubs RailsJsonInputAndOutputWithIntEnumHeaders' do
+        it 'RailsJsonInputAndOutputWithIntEnumHeaders' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -3082,7 +3082,7 @@ module RailsJson
         end
 
         # Supports handling NaN float header values.
-        it 'stubs RailsJsonSupportsNaNFloatHeaderOutputs' do
+        it 'RailsJsonSupportsNaNFloatHeaderOutputs' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -3100,7 +3100,7 @@ module RailsJson
         end
 
         # Supports handling Infinity float header values.
-        it 'stubs RailsJsonSupportsInfinityFloatHeaderOutputs' do
+        it 'RailsJsonSupportsInfinityFloatHeaderOutputs' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -3118,7 +3118,7 @@ module RailsJson
         end
 
         # Supports handling -Infinity float header values.
-        it 'stubs RailsJsonSupportsNegativeInfinityFloatHeaderOutputs' do
+        it 'RailsJsonSupportsNegativeInfinityFloatHeaderOutputs' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -3187,7 +3187,7 @@ module RailsJson
       describe 'stubs' do
 
         # Blobs are base64 encoded
-        it 'stubs RailsJsonBlobs' do
+        it 'RailsJsonBlobs' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -3310,7 +3310,7 @@ module RailsJson
       describe 'stubs' do
 
         # Serializes simple scalar properties
-        it 'stubs RailsJsonEnums' do
+        it 'RailsJsonEnums' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -3465,7 +3465,7 @@ module RailsJson
       describe 'stubs' do
 
         # Serializes intEnums as integers
-        it 'stubs RailsJsonIntEnums' do
+        it 'RailsJsonIntEnums' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -3789,7 +3789,7 @@ module RailsJson
       describe 'stubs' do
 
         # Serializes JSON lists
-        it 'stubs RailsJsonLists' do
+        it 'RailsJsonLists' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -3899,7 +3899,7 @@ module RailsJson
         end
 
         # Serializes empty JSON lists
-        it 'stubs RailsJsonListsEmpty' do
+        it 'RailsJsonListsEmpty' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -4140,7 +4140,7 @@ module RailsJson
       describe 'stubs' do
 
         # Deserializes JSON maps
-        it 'stubs RailsJsonMaps' do
+        it 'RailsJsonMaps' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -4170,7 +4170,7 @@ module RailsJson
         end
 
         # Ensure that 0 and false are sent over the wire in all maps and lists
-        it 'stubs RailsJsonDeserializesZeroValuesInMaps' do
+        it 'RailsJsonDeserializesZeroValuesInMaps' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -4196,7 +4196,7 @@ module RailsJson
         end
 
         # A response that contains a dense map of sets.
-        it 'stubs RailsJsonDeserializesDenseSetMap' do
+        it 'RailsJsonDeserializesDenseSetMap' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -4229,7 +4229,7 @@ module RailsJson
 
         # Clients SHOULD tolerate seeing a null value in a dense map, and they SHOULD
         # drop the null key-value pair.
-        it 'stubs RailsJsonDeserializesDenseSetMapAndSkipsNull' do
+        it 'RailsJsonDeserializesDenseSetMapAndSkipsNull' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -4522,7 +4522,7 @@ module RailsJson
       describe 'stubs' do
 
         # Tests how normal timestamps are serialized
-        it 'stubs RailsJsonTimestamps' do
+        it 'RailsJsonTimestamps' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -4538,7 +4538,7 @@ module RailsJson
         end
 
         # Ensures that the timestampFormat of date-time works like normal timestamps
-        it 'stubs RailsJsonTimestampsWithDateTimeFormat' do
+        it 'RailsJsonTimestampsWithDateTimeFormat' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -4554,7 +4554,7 @@ module RailsJson
         end
 
         # Ensures that the timestampFormat of date-time on the target shape works like normal timestamps
-        it 'stubs RailsJsonTimestampsWithDateTimeOnTargetFormat' do
+        it 'RailsJsonTimestampsWithDateTimeOnTargetFormat' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -4570,7 +4570,7 @@ module RailsJson
         end
 
         # Ensures that the timestampFormat of epoch-seconds works
-        it 'stubs RailsJsonTimestampsWithEpochSecondsFormat' do
+        it 'RailsJsonTimestampsWithEpochSecondsFormat' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -4586,7 +4586,7 @@ module RailsJson
         end
 
         # Ensures that the timestampFormat of epoch-seconds on the target shape works
-        it 'stubs RailsJsonTimestampsWithEpochSecondsOnTargetFormat' do
+        it 'RailsJsonTimestampsWithEpochSecondsOnTargetFormat' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -4602,7 +4602,7 @@ module RailsJson
         end
 
         # Ensures that the timestampFormat of http-date works
-        it 'stubs RailsJsonTimestampsWithHttpDateFormat' do
+        it 'RailsJsonTimestampsWithHttpDateFormat' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -4618,7 +4618,7 @@ module RailsJson
         end
 
         # Ensures that the timestampFormat of http-date on the target shape works
-        it 'stubs RailsJsonTimestampsWithHttpDateOnTargetFormat' do
+        it 'RailsJsonTimestampsWithHttpDateOnTargetFormat' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -5089,7 +5089,7 @@ module RailsJson
       describe 'stubs' do
 
         # Deserializes a string union value
-        it 'stubs RailsJsonDeserializeStringUnionValue' do
+        it 'RailsJsonDeserializeStringUnionValue' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -5109,7 +5109,7 @@ module RailsJson
         end
 
         # Deserializes a boolean union value
-        it 'stubs RailsJsonDeserializeBooleanUnionValue' do
+        it 'RailsJsonDeserializeBooleanUnionValue' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -5129,7 +5129,7 @@ module RailsJson
         end
 
         # Deserializes a number union value
-        it 'stubs RailsJsonDeserializeNumberUnionValue' do
+        it 'RailsJsonDeserializeNumberUnionValue' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -5149,7 +5149,7 @@ module RailsJson
         end
 
         # Deserializes a blob union value
-        it 'stubs RailsJsonDeserializeBlobUnionValue' do
+        it 'RailsJsonDeserializeBlobUnionValue' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -5169,7 +5169,7 @@ module RailsJson
         end
 
         # Deserializes a timestamp union value
-        it 'stubs RailsJsonDeserializeTimestampUnionValue' do
+        it 'RailsJsonDeserializeTimestampUnionValue' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -5189,7 +5189,7 @@ module RailsJson
         end
 
         # Deserializes an enum union value
-        it 'stubs RailsJsonDeserializeEnumUnionValue' do
+        it 'RailsJsonDeserializeEnumUnionValue' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -5209,7 +5209,7 @@ module RailsJson
         end
 
         # Deserializes a list union value
-        it 'stubs RailsJsonDeserializeListUnionValue' do
+        it 'RailsJsonDeserializeListUnionValue' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -5235,7 +5235,7 @@ module RailsJson
         end
 
         # Deserializes a map union value
-        it 'stubs RailsJsonDeserializeMapUnionValue' do
+        it 'RailsJsonDeserializeMapUnionValue' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -5261,7 +5261,7 @@ module RailsJson
         end
 
         # Deserializes a structure union value
-        it 'stubs RailsJsonDeserializeStructureUnionValue' do
+        it 'RailsJsonDeserializeStructureUnionValue' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -5330,7 +5330,7 @@ module RailsJson
       describe 'stubs' do
 
         # Headers that target strings with a mediaType are base64 encoded
-        it 'stubs RailsJsonMediaTypeHeaderOutputBase64' do
+        it 'RailsJsonMediaTypeHeaderOutputBase64' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -5393,7 +5393,7 @@ module RailsJson
         # When an operation does not define output, the service will respond
         # with an empty payload, and may optionally include the content-type
         # header.
-        it 'stubs RailsJsonNoInputAndNoOutput' do
+        it 'RailsJsonNoInputAndNoOutput' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -5465,7 +5465,7 @@ module RailsJson
 
         # Operations that define output and do not bind anything to
         # the payload return a JSON object in the response.
-        it 'stubs RailsJsonNoInputAndOutputWithJson' do
+        it 'RailsJsonNoInputAndOutputWithJson' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -5479,7 +5479,7 @@ module RailsJson
         # This test is similar to RailsJsonNoInputAndOutputWithJson, but
         # it ensures that clients can gracefully handle responses that
         # omit a JSON payload.
-        it 'stubs RailsJsonNoInputAndOutputNoPayload' do
+        it 'RailsJsonNoInputAndOutputNoPayload' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -5932,7 +5932,7 @@ module RailsJson
       describe 'stubs' do
 
         # Client populates default values when missing in response.
-        it 'stubs RailsJsonClientPopulatesDefaultsValuesWhenMissingInResponse' do
+        it 'RailsJsonClientPopulatesDefaultsValuesWhenMissingInResponse' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -6008,7 +6008,7 @@ module RailsJson
         end
 
         # Client ignores default values if member values are present in the response.
-        it 'stubs RailsJsonClientIgnoresDefaultValuesIfMemberValuesArePresentInResponse' do
+        it 'RailsJsonClientIgnoresDefaultValuesIfMemberValuesArePresentInResponse' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -6277,7 +6277,7 @@ module RailsJson
       describe 'stubs' do
 
         # Client populates nested default values when missing in response body.
-        it 'stubs RailsJsonClientPopulatesNestedDefaultsWhenMissingInResponseBody' do
+        it 'RailsJsonClientPopulatesNestedDefaultsWhenMissingInResponseBody' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -6430,7 +6430,7 @@ module RailsJson
       describe 'stubs' do
 
         # Unit types in unions are serialized like normal structures in responses.
-        it 'stubs RailsJsonOutputUnionWithUnitMember' do
+        it 'RailsJsonOutputUnionWithUnitMember' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -6595,7 +6595,7 @@ module RailsJson
       describe 'stubs' do
 
         # Tests that jsonName works with union members.
-        it 'stubs RailsJsonPostUnionWithJsonNameResponse1' do
+        it 'RailsJsonPostUnionWithJsonNameResponse1' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -6615,7 +6615,7 @@ module RailsJson
         end
 
         # Tests that jsonName works with union members.
-        it 'stubs RailsJsonPostUnionWithJsonNameResponse2' do
+        it 'RailsJsonPostUnionWithJsonNameResponse2' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -6635,7 +6635,7 @@ module RailsJson
         end
 
         # Tests that jsonName works with union members.
-        it 'stubs RailsJsonPostUnionWithJsonNameResponse3' do
+        it 'RailsJsonPostUnionWithJsonNameResponse3' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -6906,7 +6906,7 @@ module RailsJson
       describe 'stubs' do
 
         # Serializes recursive structures
-        it 'stubs RailsJsonRecursiveShapes' do
+        it 'RailsJsonRecursiveShapes' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -7178,7 +7178,7 @@ module RailsJson
       describe 'stubs' do
 
         # Serializes simple scalar properties
-        it 'stubs RailsJsonSimpleScalarProperties' do
+        it 'RailsJsonSimpleScalarProperties' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -7212,7 +7212,7 @@ module RailsJson
         end
 
         # Rails Json should not deserialize null structure values
-        it 'stubs RailsJsonDoesntDeserializeNullStructureValues' do
+        it 'RailsJsonDoesntDeserializeNullStructureValues' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -7224,7 +7224,7 @@ module RailsJson
         end
 
         # Supports handling NaN float values.
-        it 'stubs RailsJsonSupportsNaNFloatInputs' do
+        it 'RailsJsonSupportsNaNFloatInputs' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -7242,7 +7242,7 @@ module RailsJson
         end
 
         # Supports handling Infinity float values.
-        it 'stubs RailsJsonSupportsInfinityFloatInputs' do
+        it 'RailsJsonSupportsInfinityFloatInputs' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -7260,7 +7260,7 @@ module RailsJson
         end
 
         # Supports handling -Infinity float values.
-        it 'stubs RailsJsonSupportsNegativeInfinityFloatInputs' do
+        it 'RailsJsonSupportsNegativeInfinityFloatInputs' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -7341,7 +7341,7 @@ module RailsJson
       describe 'stubs' do
 
         # Serializes null values in sparse lists
-        it 'stubs RailsJsonSparseListsSerializeNull' do
+        it 'RailsJsonSparseListsSerializeNull' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -7694,7 +7694,7 @@ module RailsJson
       describe 'stubs' do
 
         # Deserializes JSON maps
-        it 'stubs RailsJsonSparseJsonMaps' do
+        it 'RailsJsonSparseJsonMaps' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -7724,7 +7724,7 @@ module RailsJson
         end
 
         # Deserializes null JSON map values
-        it 'stubs RailsJsonDeserializesSparseNullMapValues' do
+        it 'RailsJsonDeserializesSparseNullMapValues' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -7762,7 +7762,7 @@ module RailsJson
         end
 
         # Ensure that 0 and false are sent over the wire in all maps and lists
-        it 'stubs RailsJsonDeserializesZeroValuesInSparseMaps' do
+        it 'RailsJsonDeserializesZeroValuesInSparseMaps' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -7788,7 +7788,7 @@ module RailsJson
         end
 
         # A response that contains a sparse map of sets
-        it 'stubs RailsJsonDeserializesSparseSetMap' do
+        it 'RailsJsonDeserializesSparseSetMap' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -7820,7 +7820,7 @@ module RailsJson
         end
 
         # A response that contains a sparse map of sets.
-        it 'stubs RailsJsonDeserializesSparseSetMapAndRetainsNull' do
+        it 'RailsJsonDeserializesSparseSetMapAndRetainsNull' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -7941,7 +7941,7 @@ module RailsJson
       describe 'stubs' do
 
         # Serializes a blob in the HTTP payload
-        it 'stubs RailsJsonStreamingTraitsWithBlob', rbs_test: :skip do
+        it 'RailsJsonStreamingTraitsWithBlob', rbs_test: :skip do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -7962,7 +7962,7 @@ module RailsJson
         end
 
         # Serializes an empty blob in the HTTP payload
-        it 'stubs RailsJsonStreamingTraitsWithNoBlobBody', rbs_test: :skip do
+        it 'RailsJsonStreamingTraitsWithNoBlobBody', rbs_test: :skip do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -8076,7 +8076,7 @@ module RailsJson
       describe 'stubs' do
 
         # Serializes a blob in the HTTP payload with a content-type
-        it 'stubs RailsJsonStreamingTraitsWithMediaTypeWithBlob', rbs_test: :skip do
+        it 'RailsJsonStreamingTraitsWithMediaTypeWithBlob', rbs_test: :skip do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -8343,7 +8343,7 @@ module RailsJson
       describe 'stubs' do
 
         # Tests how timestamp response headers are serialized
-        it 'stubs RailsJsonTimestampFormatHeaders' do
+        it 'RailsJsonTimestampFormatHeaders' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -8418,7 +8418,7 @@ module RailsJson
         # When an operation defines Unit output, the service will respond
         # with an empty payload, and may optionally include the content-type
         # header.
-        it 'stubs RailsJsonUnitInputAndOutputNoOutput' do
+        it 'RailsJsonUnitInputAndOutputNoOutput' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
diff --git a/codegen/projections/rpcv2_cbor/lib/rpcv2_cbor/auth.rb b/codegen/projections/rpcv2_cbor/lib/rpcv2_cbor/auth.rb
index 29d14dd29..4370af115 100644
--- a/codegen/projections/rpcv2_cbor/lib/rpcv2_cbor/auth.rb
+++ b/codegen/projections/rpcv2_cbor/lib/rpcv2_cbor/auth.rb
@@ -9,7 +9,13 @@
 
 module Rpcv2Cbor
   module Auth
-    Params = Struct.new(:operation_name, keyword_init: true)
+    class Params
+      def initialize(operation_name: nil)
+        @operation_name = operation_name
+      end
+
+      attr_accessor :operation_name
+    end
 
     SCHEMES = [
       Hearth::AuthSchemes::Anonymous.new
diff --git a/codegen/projections/rpcv2_cbor/lib/rpcv2_cbor/config.rb b/codegen/projections/rpcv2_cbor/lib/rpcv2_cbor/config.rb
index 74d498c6f..1720178b6 100644
--- a/codegen/projections/rpcv2_cbor/lib/rpcv2_cbor/config.rb
+++ b/codegen/projections/rpcv2_cbor/lib/rpcv2_cbor/config.rb
@@ -82,24 +82,27 @@ module Rpcv2Cbor
   #   @return [Hearth::Stubs]
   # @!attribute validate_input
   #   @return [Boolean]
-  Config = ::Struct.new(
-    :auth_resolver,
-    :auth_schemes,
-    :disable_host_prefix,
-    :endpoint,
-    :endpoint_resolver,
-    :http_client,
-    :interceptors,
-    :logger,
-    :plugins,
-    :retry_strategy,
-    :stub_responses,
-    :stubs,
-    :validate_input,
-    keyword_init: true
-  ) do
+  class Config
     include Hearth::Configuration
 
+    MEMBERS = %i[
+      auth_resolver
+      auth_schemes
+      disable_host_prefix
+      endpoint
+      endpoint_resolver
+      http_client
+      interceptors
+      logger
+      plugins
+      retry_strategy
+      stub_responses
+      stubs
+      validate_input
+    ].freeze
+
+    attr_accessor(*MEMBERS)
+
     # Validates the configuration.
     def validate!
       Hearth::Validator.validate_responds_to!(auth_resolver, :resolve, context: 'config[:auth_resolver]')
diff --git a/codegen/projections/rpcv2_cbor/lib/rpcv2_cbor/endpoint.rb b/codegen/projections/rpcv2_cbor/lib/rpcv2_cbor/endpoint.rb
index e1dc58d03..1230c1f21 100644
--- a/codegen/projections/rpcv2_cbor/lib/rpcv2_cbor/endpoint.rb
+++ b/codegen/projections/rpcv2_cbor/lib/rpcv2_cbor/endpoint.rb
@@ -9,11 +9,12 @@
 
 module Rpcv2Cbor
   module Endpoint
-    Params = ::Struct.new(
-      :endpoint,
-      keyword_init: true
-    ) do
-      include Hearth::Structure
+    class Params
+      def initialize(endpoint: nil)
+        @endpoint = endpoint
+      end
+
+      attr_accessor :endpoint
     end
 
     class Resolver
diff --git a/codegen/projections/rpcv2_cbor/lib/rpcv2_cbor/plugins/global_config.rb b/codegen/projections/rpcv2_cbor/lib/rpcv2_cbor/plugins/global_config.rb
index ade9ac355..fece29c29 100644
--- a/codegen/projections/rpcv2_cbor/lib/rpcv2_cbor/plugins/global_config.rb
+++ b/codegen/projections/rpcv2_cbor/lib/rpcv2_cbor/plugins/global_config.rb
@@ -17,7 +17,7 @@ class GlobalConfig
       def call(config)
         options = config.options
         ::Hearth.config.each do |key, value|
-          config[key] = value unless options.key?(key)
+          config.send("#{key}=", value) unless options.key?(key)
         end
       end
 
diff --git a/codegen/projections/rpcv2_cbor/sig/rpcv2_cbor/auth.rbs b/codegen/projections/rpcv2_cbor/sig/rpcv2_cbor/auth.rbs
index 134c58757..7de734db6 100644
--- a/codegen/projections/rpcv2_cbor/sig/rpcv2_cbor/auth.rbs
+++ b/codegen/projections/rpcv2_cbor/sig/rpcv2_cbor/auth.rbs
@@ -9,7 +9,8 @@
 
 module Rpcv2Cbor
   module Auth
-    class Params < ::Struct[untyped]
+    class Params
+      def initialize: (?operation_name: ::Symbol?) -> void
       attr_accessor operation_name (): ::Symbol
     end
 
diff --git a/codegen/projections/rpcv2_cbor/sig/rpcv2_cbor/config.rbs b/codegen/projections/rpcv2_cbor/sig/rpcv2_cbor/config.rbs
index ab6dcc1e3..9dfd2854c 100644
--- a/codegen/projections/rpcv2_cbor/sig/rpcv2_cbor/config.rbs
+++ b/codegen/projections/rpcv2_cbor/sig/rpcv2_cbor/config.rbs
@@ -1,20 +1,19 @@
 module Rpcv2Cbor
-  class Config < ::Struct[untyped]
+  class Config
     include Hearth::Configuration[instance]
-
-    attr_accessor auth_resolver (): Hearth::_AuthResolver[Auth::Params]
-    attr_accessor auth_schemes (): Array[Hearth::AuthSchemes::Base]
-    attr_accessor disable_host_prefix (): bool
-    attr_accessor endpoint (): String
-    attr_accessor endpoint_resolver (): Hearth::_EndpointResolver[Endpoint::Params]
-    attr_accessor http_client (): Hearth::HTTP::Client
-    attr_accessor interceptors (): Hearth::InterceptorList[Config]
-    attr_accessor logger (): Logger
-    attr_accessor plugins (): Hearth::PluginList[Config]
-    attr_accessor retry_strategy (): Hearth::_RetryStrategy
-    attr_accessor stub_responses (): bool
-    attr_accessor stubs (): Hearth::Stubs
-    attr_accessor validate_input (): bool
+    attr_accessor auth_resolver (): Hearth::_AuthResolver[Auth::Params]?
+    attr_accessor auth_schemes (): Array[Hearth::AuthSchemes::Base]?
+    attr_accessor disable_host_prefix (): bool?
+    attr_accessor endpoint (): String?
+    attr_accessor endpoint_resolver (): Hearth::_EndpointResolver[Endpoint::Params]?
+    attr_accessor http_client (): Hearth::HTTP::Client?
+    attr_accessor interceptors (): Hearth::InterceptorList[Config]?
+    attr_accessor logger (): Logger?
+    attr_accessor plugins (): Hearth::PluginList[Config]?
+    attr_accessor retry_strategy (): Hearth::_RetryStrategy?
+    attr_accessor stub_responses (): bool?
+    attr_accessor stubs (): Hearth::Stubs?
+    attr_accessor validate_input (): bool?
 
     def validate!: () -> void
   end
diff --git a/codegen/projections/rpcv2_cbor/sig/rpcv2_cbor/endpoint.rbs b/codegen/projections/rpcv2_cbor/sig/rpcv2_cbor/endpoint.rbs
index 84005eb83..92e364f37 100644
--- a/codegen/projections/rpcv2_cbor/sig/rpcv2_cbor/endpoint.rbs
+++ b/codegen/projections/rpcv2_cbor/sig/rpcv2_cbor/endpoint.rbs
@@ -9,8 +9,9 @@
 
 module Rpcv2Cbor
   module Endpoint
-    class Params < ::Struct[untyped]
-      attr_accessor endpoint: ::String
+    class Params
+      def initialize: (?endpoint: ::String?) -> void
+      attr_accessor endpoint (): ::String?
     end
 
     class Resolver
diff --git a/codegen/projections/rpcv2_cbor/sig/rpcv2_cbor/types.rbs b/codegen/projections/rpcv2_cbor/sig/rpcv2_cbor/types.rbs
index 690288180..e0a72cbf3 100644
--- a/codegen/projections/rpcv2_cbor/sig/rpcv2_cbor/types.rbs
+++ b/codegen/projections/rpcv2_cbor/sig/rpcv2_cbor/types.rbs
@@ -319,14 +319,14 @@ module Rpcv2Cbor
 
     class ValidationException
       include Hearth::Structure
-      attr_accessor message (): ::String
+      attr_accessor message (): ::String?
       attr_accessor field_list (): ::Array[Types::ValidationExceptionField]?
     end
 
     class ValidationExceptionField
       include Hearth::Structure
-      attr_accessor path (): ::String
-      attr_accessor message (): ::String
+      attr_accessor path (): ::String?
+      attr_accessor message (): ::String?
     end
 
   end
diff --git a/codegen/projections/rpcv2_cbor/spec/protocol_spec.rb b/codegen/projections/rpcv2_cbor/spec/protocol_spec.rb
index b1accac27..3d9666385 100644
--- a/codegen/projections/rpcv2_cbor/spec/protocol_spec.rb
+++ b/codegen/projections/rpcv2_cbor/spec/protocol_spec.rb
@@ -80,7 +80,7 @@ module Rpcv2Cbor
       describe 'stubs' do
 
         # When output structure is empty we write CBOR equivalent of {}
-        it 'stubs empty_output' do
+        it 'empty_output' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -92,7 +92,7 @@ module Rpcv2Cbor
         end
 
         # When output structure is empty the client should accept an empty body
-        it 'stubs empty_output_no_body' do
+        it 'empty_output_no_body' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -196,7 +196,7 @@ module Rpcv2Cbor
       describe 'stubs' do
 
         # Ensures that clients can correctly parse float16 +Inf.
-        it 'stubs RpcV2CborFloat16Inf' do
+        it 'RpcV2CborFloat16Inf' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -212,7 +212,7 @@ module Rpcv2Cbor
         end
 
         # Ensures that clients can correctly parse float16 -Inf.
-        it 'stubs RpcV2CborFloat16NegInf' do
+        it 'RpcV2CborFloat16NegInf' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -228,7 +228,7 @@ module Rpcv2Cbor
         end
 
         # Ensures that clients can correctly parse float16 NaN with high LSB.
-        it 'stubs RpcV2CborFloat16LSBNaN' do
+        it 'RpcV2CborFloat16LSBNaN' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -244,7 +244,7 @@ module Rpcv2Cbor
         end
 
         # Ensures that clients can correctly parse float16 NaN with high MSB.
-        it 'stubs RpcV2CborFloat16MSBNaN' do
+        it 'RpcV2CborFloat16MSBNaN' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -260,7 +260,7 @@ module Rpcv2Cbor
         end
 
         # Ensures that clients can correctly parse a subnormal float16.
-        it 'stubs RpcV2CborFloat16Subnormal' do
+        it 'RpcV2CborFloat16Subnormal' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -304,7 +304,7 @@ module Rpcv2Cbor
       describe 'stubs' do
 
         # Ensures that clients can correctly parse timestamps with fractional seconds
-        it 'stubs RpcV2CborDateTimeWithFractionalSeconds' do
+        it 'RpcV2CborDateTimeWithFractionalSeconds' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -511,7 +511,7 @@ module Rpcv2Cbor
       describe 'stubs' do
 
         # A `Content-Type` header should not be set if the response body is empty.
-        it 'stubs no_output' do
+        it 'no_output' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -523,7 +523,7 @@ module Rpcv2Cbor
         end
 
         # Clients should accept a CBOR empty struct if there is no output.
-        it 'stubs NoOutputClientAllowsEmptyCbor' do
+        it 'NoOutputClientAllowsEmptyCbor' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -536,7 +536,7 @@ module Rpcv2Cbor
 
         # Clients should accept an empty body if there is no output and
         # should not raise an error if the `Content-Type` header is set.
-        it 'stubs NoOutputClientAllowsEmptyBody' do
+        it 'NoOutputClientAllowsEmptyBody' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -760,7 +760,7 @@ module Rpcv2Cbor
       describe 'stubs' do
 
         # Client populates default values when missing in response.
-        it 'stubs RpcV2CborClientPopulatesDefaultsValuesWhenMissingInResponse' do
+        it 'RpcV2CborClientPopulatesDefaultsValuesWhenMissingInResponse' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -828,7 +828,7 @@ module Rpcv2Cbor
         end
 
         # Client ignores default values if member values are present in the response.
-        it 'stubs RpcV2CborClientIgnoresDefaultValuesIfMemberValuesArePresentInResponse' do
+        it 'RpcV2CborClientIgnoresDefaultValuesIfMemberValuesArePresentInResponse' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -941,7 +941,7 @@ module Rpcv2Cbor
       describe 'stubs' do
 
         # When output is empty we write CBOR equivalent of {}
-        it 'stubs optional_output' do
+        it 'optional_output' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -1051,7 +1051,7 @@ module Rpcv2Cbor
       describe 'stubs' do
 
         # Serializes recursive structures
-        it 'stubs RpcV2CborRecursiveShapes' do
+        it 'RpcV2CborRecursiveShapes' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -1089,7 +1089,7 @@ module Rpcv2Cbor
         end
 
         # Deserializes recursive structures encoded using a map with definite length
-        it 'stubs RpcV2CborRecursiveShapesUsingDefiniteLength' do
+        it 'RpcV2CborRecursiveShapesUsingDefiniteLength' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -1307,7 +1307,7 @@ module Rpcv2Cbor
       describe 'stubs' do
 
         # Deserializes maps
-        it 'stubs RpcV2CborMaps' do
+        it 'RpcV2CborMaps' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -1337,7 +1337,7 @@ module Rpcv2Cbor
         end
 
         # Ensure that 0 and false are sent over the wire in all maps and lists
-        it 'stubs RpcV2CborDeserializesZeroValuesInMaps' do
+        it 'RpcV2CborDeserializesZeroValuesInMaps' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -1363,7 +1363,7 @@ module Rpcv2Cbor
         end
 
         # A response that contains a dense map of sets
-        it 'stubs RpcV2CborDeserializesDenseSetMap' do
+        it 'RpcV2CborDeserializesDenseSetMap' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -1396,7 +1396,7 @@ module Rpcv2Cbor
 
         # Clients SHOULD tolerate seeing a null value in a dense map, and they SHOULD
         # drop the null key-value pair.
-        it 'stubs RpcV2CborDeserializesDenseSetMapAndSkipsNull' do
+        it 'RpcV2CborDeserializesDenseSetMapAndSkipsNull' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -1675,7 +1675,7 @@ module Rpcv2Cbor
       describe 'stubs' do
 
         # Serializes RpcV2 Cbor lists
-        it 'stubs RpcV2CborLists' do
+        it 'RpcV2CborLists' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -1793,7 +1793,7 @@ module Rpcv2Cbor
         end
 
         # Serializes empty RpcV2 Cbor lists
-        it 'stubs RpcV2CborListsEmpty' do
+        it 'RpcV2CborListsEmpty' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -1813,7 +1813,7 @@ module Rpcv2Cbor
         end
 
         # Can deserialize indefinite length text strings inside an indefinite length list
-        it 'stubs RpcV2CborIndefiniteStringInsideIndefiniteListCanDeserialize' do
+        it 'RpcV2CborIndefiniteStringInsideIndefiniteListCanDeserialize' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -1837,7 +1837,7 @@ module Rpcv2Cbor
         end
 
         # Can deserialize indefinite length text strings inside a definite length list
-        it 'stubs RpcV2CborIndefiniteStringInsideDefiniteListCanDeserialize' do
+        it 'RpcV2CborIndefiniteStringInsideDefiniteListCanDeserialize' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -2122,7 +2122,7 @@ module Rpcv2Cbor
       describe 'stubs' do
 
         # Deserializes sparse maps
-        it 'stubs RpcV2CborSparseJsonMaps' do
+        it 'RpcV2CborSparseJsonMaps' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -2152,7 +2152,7 @@ module Rpcv2Cbor
         end
 
         # Deserializes null map values
-        it 'stubs RpcV2CborDeserializesNullMapValues' do
+        it 'RpcV2CborDeserializesNullMapValues' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -2190,7 +2190,7 @@ module Rpcv2Cbor
         end
 
         # A response that contains a sparse map of sets
-        it 'stubs RpcV2CborDeserializesSparseSetMap' do
+        it 'RpcV2CborDeserializesSparseSetMap' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -2222,7 +2222,7 @@ module Rpcv2Cbor
         end
 
         # A response that contains a sparse map of sets with a null
-        it 'stubs RpcV2CborDeserializesSparseSetMapAndRetainsNull' do
+        it 'RpcV2CborDeserializesSparseSetMapAndRetainsNull' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -2256,7 +2256,7 @@ module Rpcv2Cbor
         end
 
         # Ensure that 0 and false are sent over the wire in all maps and lists
-        it 'stubs RpcV2CborDeserializesZeroValuesInSparseMaps' do
+        it 'RpcV2CborDeserializesZeroValuesInSparseMaps' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -2555,7 +2555,7 @@ module Rpcv2Cbor
       describe 'stubs' do
 
         # Serializes simple scalar properties
-        it 'stubs RpcV2CborSimpleScalarProperties' do
+        it 'RpcV2CborSimpleScalarProperties' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -2587,7 +2587,7 @@ module Rpcv2Cbor
         end
 
         # Deserializes simple scalar properties encoded using a map with definite length
-        it 'stubs RpcV2CborSimpleScalarPropertiesUsingDefiniteLength' do
+        it 'RpcV2CborSimpleScalarPropertiesUsingDefiniteLength' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -2619,7 +2619,7 @@ module Rpcv2Cbor
         end
 
         # RpcV2 Cbor should not deserialize null structure values
-        it 'stubs RpcV2CborClientDoesntDeserializeNullStructureValues' do
+        it 'RpcV2CborClientDoesntDeserializeNullStructureValues' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -2631,7 +2631,7 @@ module Rpcv2Cbor
         end
 
         # Supports handling NaN float values.
-        it 'stubs RpcV2CborSupportsNaNFloatOutputs' do
+        it 'RpcV2CborSupportsNaNFloatOutputs' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -2649,7 +2649,7 @@ module Rpcv2Cbor
         end
 
         # Supports handling Infinity float values.
-        it 'stubs RpcV2CborSupportsInfinityFloatOutputs' do
+        it 'RpcV2CborSupportsInfinityFloatOutputs' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -2667,7 +2667,7 @@ module Rpcv2Cbor
         end
 
         # Supports handling Negative Infinity float values.
-        it 'stubs RpcV2CborSupportsNegativeInfinityFloatOutputs' do
+        it 'RpcV2CborSupportsNegativeInfinityFloatOutputs' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -2685,7 +2685,7 @@ module Rpcv2Cbor
         end
 
         # Supports upcasting from a smaller byte representation of the same data type.
-        it 'stubs RpcV2CborSupportsUpcastingDataOnDeserialize' do
+        it 'RpcV2CborSupportsUpcastingDataOnDeserialize' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -2711,7 +2711,7 @@ module Rpcv2Cbor
         # The client should skip over additional fields that are not part of the structure. This allows a
         # client generated against an older Smithy model to be able to communicate with a server that is
         # generated against a newer Smithy model.
-        it 'stubs RpcV2CborExtraFieldsInTheBodyShouldBeSkippedByClients' do
+        it 'RpcV2CborExtraFieldsInTheBodyShouldBeSkippedByClients' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -2835,7 +2835,7 @@ module Rpcv2Cbor
       describe 'stubs' do
 
         # Deserializes null values in maps
-        it 'stubs RpcV2CborSparseMapsDeserializeNullValues' do
+        it 'RpcV2CborSparseMapsDeserializeNullValues' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
@@ -2855,7 +2855,7 @@ module Rpcv2Cbor
         end
 
         # Deserializes null values in lists
-        it 'stubs RpcV2CborSparseListsDeserializeNull' do
+        it 'RpcV2CborSparseListsDeserializeNull' do
           proc = proc do |context|
             expect(context.response.status).to eq(200)
           end
diff --git a/codegen/projections/white_label/lib/white_label/auth.rb b/codegen/projections/white_label/lib/white_label/auth.rb
index cf77b3602..df8f7d767 100644
--- a/codegen/projections/white_label/lib/white_label/auth.rb
+++ b/codegen/projections/white_label/lib/white_label/auth.rb
@@ -11,7 +11,14 @@
 
 module WhiteLabel
   module Auth
-    Params = Struct.new(:custom_param, :operation_name, keyword_init: true)
+    class Params
+      def initialize(custom_param: nil, operation_name: nil)
+        @custom_param = custom_param
+        @operation_name = operation_name
+      end
+
+      attr_accessor :custom_param, :operation_name
+    end
 
     SCHEMES = [
       Hearth::AuthSchemes::HTTPApiKey.new,
diff --git a/codegen/projections/white_label/lib/white_label/config.rb b/codegen/projections/white_label/lib/white_label/config.rb
index 1ee875e3b..63d320f14 100644
--- a/codegen/projections/white_label/lib/white_label/config.rb
+++ b/codegen/projections/white_label/lib/white_label/config.rb
@@ -119,33 +119,36 @@ module WhiteLabel
   #   @return [String]
   # @!attribute validate_input
   #   @return [Boolean]
-  Config = ::Struct.new(
-    :auth_resolver,
-    :auth_schemes,
-    :disable_host_prefix,
-    :disable_request_compression,
-    :endpoint,
-    :endpoint_resolver,
-    :http2_client,
-    :http_api_key_provider,
-    :http_bearer_provider,
-    :http_client,
-    :http_custom_key_provider,
-    :http_login_provider,
-    :interceptors,
-    :logger,
-    :plugins,
-    :request_min_compression_size_bytes,
-    :retry_strategy,
-    :stage,
-    :stub_responses,
-    :stubs,
-    :test_config,
-    :validate_input,
-    keyword_init: true
-  ) do
+  class Config
     include Hearth::Configuration
 
+    MEMBERS = %i[
+      auth_resolver
+      auth_schemes
+      disable_host_prefix
+      disable_request_compression
+      endpoint
+      endpoint_resolver
+      http2_client
+      http_api_key_provider
+      http_bearer_provider
+      http_client
+      http_custom_key_provider
+      http_login_provider
+      interceptors
+      logger
+      plugins
+      request_min_compression_size_bytes
+      retry_strategy
+      stage
+      stub_responses
+      stubs
+      test_config
+      validate_input
+    ].freeze
+
+    attr_accessor(*MEMBERS)
+
     # Validates the configuration.
     def validate!
       Hearth::Validator.validate_responds_to!(auth_resolver, :resolve, context: 'config[:auth_resolver]')
diff --git a/codegen/projections/white_label/lib/white_label/endpoint.rb b/codegen/projections/white_label/lib/white_label/endpoint.rb
index 5a0b88aa9..f68ed7d7d 100644
--- a/codegen/projections/white_label/lib/white_label/endpoint.rb
+++ b/codegen/projections/white_label/lib/white_label/endpoint.rb
@@ -9,14 +9,15 @@
 
 module WhiteLabel
   module Endpoint
-    Params = ::Struct.new(
-      :stage,
-      :dataplane,
-      :resource_url,
-      :endpoint,
-      keyword_init: true
-    ) do
-      include Hearth::Structure
+    class Params
+      def initialize(stage: nil, dataplane: nil, resource_url: nil, endpoint: nil)
+        @stage = stage
+        @dataplane = dataplane
+        @resource_url = resource_url
+        @endpoint = endpoint
+      end
+
+      attr_accessor :stage, :dataplane, :resource_url, :endpoint
     end
 
     class Resolver
diff --git a/codegen/projections/white_label/lib/white_label/plugins/global_config.rb b/codegen/projections/white_label/lib/white_label/plugins/global_config.rb
index a7ca383c8..e001e5f85 100644
--- a/codegen/projections/white_label/lib/white_label/plugins/global_config.rb
+++ b/codegen/projections/white_label/lib/white_label/plugins/global_config.rb
@@ -17,7 +17,7 @@ class GlobalConfig
       def call(config)
         options = config.options
         ::Hearth.config.each do |key, value|
-          config[key] = value unless options.key?(key)
+          config.send("#{key}=", value) unless options.key?(key)
         end
       end
 
diff --git a/codegen/projections/white_label/lib/white_label/types.rb b/codegen/projections/white_label/lib/white_label/types.rb
index fc54755c2..cf4ad2270 100644
--- a/codegen/projections/white_label/lib/white_label/types.rb
+++ b/codegen/projections/white_label/lib/white_label/types.rb
@@ -175,26 +175,26 @@ class Defaults
       attr_accessor(*MEMBERS)
 
       def to_s
-        "#<WhiteLabel::Types::Defaults "\
-          "string=#{string || 'nil'}, "\
-          "struct=\"[SENSITIVE]\", "\
-          "un_required_number=#{un_required_number || 'nil'}, "\
-          "un_required_bool=#{un_required_bool || 'nil'}, "\
-          "number=#{number || 'nil'}, "\
-          "bool=#{bool || 'nil'}, "\
-          "hello=#{hello || 'nil'}, "\
-          "simple_enum=#{simple_enum || 'nil'}, "\
-          "valued_enum=#{valued_enum || 'nil'}, "\
-          "int_enum=#{int_enum || 'nil'}, "\
-          "null_document=#{null_document || 'nil'}, "\
-          "string_document=#{string_document || 'nil'}, "\
-          "boolean_document=#{boolean_document || 'nil'}, "\
-          "numbers_document=#{numbers_document || 'nil'}, "\
-          "list_document=#{list_document || 'nil'}, "\
-          "map_document=#{map_document || 'nil'}, "\
-          "list_of_strings=#{list_of_strings || 'nil'}, "\
-          "map_of_strings=#{map_of_strings || 'nil'}, "\
-          "iso8601_timestamp=#{iso8601_timestamp || 'nil'}, "\
+        '#<WhiteLabel::Types::Defaults ' \
+          "string=#{string || 'nil'}, " \
+          'struct=[SENSITIVE], ' \
+          "un_required_number=#{un_required_number || 'nil'}, " \
+          "un_required_bool=#{un_required_bool || 'nil'}, " \
+          "number=#{number || 'nil'}, " \
+          "bool=#{bool || 'nil'}, " \
+          "hello=#{hello || 'nil'}, " \
+          "simple_enum=#{simple_enum || 'nil'}, " \
+          "valued_enum=#{valued_enum || 'nil'}, " \
+          "int_enum=#{int_enum || 'nil'}, " \
+          "null_document=#{null_document || 'nil'}, " \
+          "string_document=#{string_document || 'nil'}, " \
+          "boolean_document=#{boolean_document || 'nil'}, " \
+          "numbers_document=#{numbers_document || 'nil'}, " \
+          "list_document=#{list_document || 'nil'}, " \
+          "map_document=#{map_document || 'nil'}, " \
+          "list_of_strings=#{list_of_strings || 'nil'}, " \
+          "map_of_strings=#{map_of_strings || 'nil'}, " \
+          "iso8601_timestamp=#{iso8601_timestamp || 'nil'}, " \
           "epoch_timestamp=#{epoch_timestamp || 'nil'}>"
       end
 
@@ -348,26 +348,26 @@ class DefaultsTestOutput
       attr_accessor(*MEMBERS)
 
       def to_s
-        "#<WhiteLabel::Types::DefaultsTestOutput "\
-          "string=#{string || 'nil'}, "\
-          "struct=\"[SENSITIVE]\", "\
-          "un_required_number=#{un_required_number || 'nil'}, "\
-          "un_required_bool=#{un_required_bool || 'nil'}, "\
-          "number=#{number || 'nil'}, "\
-          "bool=#{bool || 'nil'}, "\
-          "hello=#{hello || 'nil'}, "\
-          "simple_enum=#{simple_enum || 'nil'}, "\
-          "valued_enum=#{valued_enum || 'nil'}, "\
-          "int_enum=#{int_enum || 'nil'}, "\
-          "null_document=#{null_document || 'nil'}, "\
-          "string_document=#{string_document || 'nil'}, "\
-          "boolean_document=#{boolean_document || 'nil'}, "\
-          "numbers_document=#{numbers_document || 'nil'}, "\
-          "list_document=#{list_document || 'nil'}, "\
-          "map_document=#{map_document || 'nil'}, "\
-          "list_of_strings=#{list_of_strings || 'nil'}, "\
-          "map_of_strings=#{map_of_strings || 'nil'}, "\
-          "iso8601_timestamp=#{iso8601_timestamp || 'nil'}, "\
+        '#<WhiteLabel::Types::DefaultsTestOutput ' \
+          "string=#{string || 'nil'}, " \
+          'struct=[SENSITIVE], ' \
+          "un_required_number=#{un_required_number || 'nil'}, " \
+          "un_required_bool=#{un_required_bool || 'nil'}, " \
+          "number=#{number || 'nil'}, " \
+          "bool=#{bool || 'nil'}, " \
+          "hello=#{hello || 'nil'}, " \
+          "simple_enum=#{simple_enum || 'nil'}, " \
+          "valued_enum=#{valued_enum || 'nil'}, " \
+          "int_enum=#{int_enum || 'nil'}, " \
+          "null_document=#{null_document || 'nil'}, " \
+          "string_document=#{string_document || 'nil'}, " \
+          "boolean_document=#{boolean_document || 'nil'}, " \
+          "numbers_document=#{numbers_document || 'nil'}, " \
+          "list_document=#{list_document || 'nil'}, " \
+          "map_document=#{map_document || 'nil'}, " \
+          "list_of_strings=#{list_of_strings || 'nil'}, " \
+          "map_of_strings=#{map_of_strings || 'nil'}, " \
+          "iso8601_timestamp=#{iso8601_timestamp || 'nil'}, " \
           "epoch_timestamp=#{epoch_timestamp || 'nil'}>"
       end
 
@@ -697,17 +697,17 @@ class KitchenSinkInput
       attr_accessor(*MEMBERS)
 
       def to_s
-        "#<WhiteLabel::Types::KitchenSinkInput "\
-          "string=#{string || 'nil'}, "\
-          "simple_enum=#{simple_enum || 'nil'}, "\
-          "valued_enum=#{valued_enum || 'nil'}, "\
-          "struct=\"[SENSITIVE]\", "\
-          "document=#{document || 'nil'}, "\
-          "list_of_strings=#{list_of_strings || 'nil'}, "\
-          "list_of_structs=#{list_of_structs || 'nil'}, "\
-          "map_of_strings=#{map_of_strings || 'nil'}, "\
-          "map_of_structs=#{map_of_structs || 'nil'}, "\
-          "union=\"[SENSITIVE]\">"
+        '#<WhiteLabel::Types::KitchenSinkInput ' \
+          "string=#{string || 'nil'}, " \
+          "simple_enum=#{simple_enum || 'nil'}, " \
+          "valued_enum=#{valued_enum || 'nil'}, " \
+          'struct=[SENSITIVE], ' \
+          "document=#{document || 'nil'}, " \
+          "list_of_strings=#{list_of_strings || 'nil'}, " \
+          "list_of_structs=#{list_of_structs || 'nil'}, " \
+          "map_of_strings=#{map_of_strings || 'nil'}, " \
+          "map_of_structs=#{map_of_structs || 'nil'}, " \
+          'union=[SENSITIVE]>'
       end
     end
 
@@ -812,17 +812,17 @@ class KitchenSinkOutput
       attr_accessor(*MEMBERS)
 
       def to_s
-        "#<WhiteLabel::Types::KitchenSinkOutput "\
-          "string=#{string || 'nil'}, "\
-          "simple_enum=#{simple_enum || 'nil'}, "\
-          "valued_enum=#{valued_enum || 'nil'}, "\
-          "struct=\"[SENSITIVE]\", "\
-          "document=#{document || 'nil'}, "\
-          "list_of_strings=#{list_of_strings || 'nil'}, "\
-          "list_of_structs=#{list_of_structs || 'nil'}, "\
-          "map_of_strings=#{map_of_strings || 'nil'}, "\
-          "map_of_structs=#{map_of_structs || 'nil'}, "\
-          "union=\"[SENSITIVE]\">"
+        '#<WhiteLabel::Types::KitchenSinkOutput ' \
+          "string=#{string || 'nil'}, " \
+          "simple_enum=#{simple_enum || 'nil'}, " \
+          "valued_enum=#{valued_enum || 'nil'}, " \
+          'struct=[SENSITIVE], ' \
+          "document=#{document || 'nil'}, " \
+          "list_of_strings=#{list_of_strings || 'nil'}, " \
+          "list_of_structs=#{list_of_structs || 'nil'}, " \
+          "map_of_strings=#{map_of_strings || 'nil'}, " \
+          "map_of_structs=#{map_of_structs || 'nil'}, " \
+          'union=[SENSITIVE]>'
       end
     end
 
@@ -1281,10 +1281,6 @@ class String < Union
         def to_h
           { string: super(__getobj__) }
         end
-
-        def to_s
-          "#<WhiteLabel::Types::String #{__getobj__ || 'nil'}>"
-        end
       end
 
       # This docstring should be different than KitchenSink struct member.
diff --git a/codegen/projections/white_label/sig/white_label/auth.rbs b/codegen/projections/white_label/sig/white_label/auth.rbs
index 6327e27f7..06da5ffe8 100644
--- a/codegen/projections/white_label/sig/white_label/auth.rbs
+++ b/codegen/projections/white_label/sig/white_label/auth.rbs
@@ -9,7 +9,8 @@
 
 module WhiteLabel
   module Auth
-    class Params < ::Struct[untyped]
+    class Params
+      def initialize: (?custom_param: ::String?, ?operation_name: ::Symbol?) -> void
       attr_accessor custom_param (): ::String
       attr_accessor operation_name (): ::Symbol
     end
diff --git a/codegen/projections/white_label/sig/white_label/client.rbs b/codegen/projections/white_label/sig/white_label/client.rbs
index a98e6342f..be84b0719 100644
--- a/codegen/projections/white_label/sig/white_label/client.rbs
+++ b/codegen/projections/white_label/sig/white_label/client.rbs
@@ -24,7 +24,7 @@ module WhiteLabel
         ?http_api_key_provider: Hearth::IdentityProvider,
         ?http_bearer_provider: Hearth::IdentityProvider,
         ?http_client: Hearth::HTTP::Client,
-        ?http_custom_key_provider: untyped,
+        ?http_custom_key_provider: Hearth::IdentityProvider,
         ?http_login_provider: Hearth::IdentityProvider,
         ?interceptors: Hearth::InterceptorList[Config],
         ?logger: Logger,
diff --git a/codegen/projections/white_label/sig/white_label/config.rbs b/codegen/projections/white_label/sig/white_label/config.rbs
index 79979eee8..046e0b4be 100644
--- a/codegen/projections/white_label/sig/white_label/config.rbs
+++ b/codegen/projections/white_label/sig/white_label/config.rbs
@@ -1,29 +1,28 @@
 module WhiteLabel
-  class Config < ::Struct[untyped]
+  class Config
     include Hearth::Configuration[instance]
-
-    attr_accessor auth_resolver (): Hearth::_AuthResolver[Auth::Params]
-    attr_accessor auth_schemes (): Array[Hearth::AuthSchemes::Base]
-    attr_accessor disable_host_prefix (): bool
-    attr_accessor disable_request_compression (): bool
-    attr_accessor endpoint (): String
-    attr_accessor endpoint_resolver (): Hearth::_EndpointResolver[Endpoint::Params]
-    attr_accessor http2_client (): Hearth::HTTP2::Client
-    attr_accessor http_api_key_provider (): Hearth::IdentityProvider
-    attr_accessor http_bearer_provider (): Hearth::IdentityProvider
-    attr_accessor http_client (): Hearth::HTTP::Client
-    attr_accessor http_custom_key_provider (): untyped
-    attr_accessor http_login_provider (): Hearth::IdentityProvider
-    attr_accessor interceptors (): Hearth::InterceptorList[Config]
-    attr_accessor logger (): Logger
-    attr_accessor plugins (): Hearth::PluginList[Config]
-    attr_accessor request_min_compression_size_bytes (): Integer
-    attr_accessor retry_strategy (): Hearth::_RetryStrategy
-    attr_accessor stage (): String
-    attr_accessor stub_responses (): bool
-    attr_accessor stubs (): Hearth::Stubs
-    attr_accessor test_config (): untyped
-    attr_accessor validate_input (): bool
+    attr_accessor auth_resolver (): Hearth::_AuthResolver[Auth::Params]?
+    attr_accessor auth_schemes (): Array[Hearth::AuthSchemes::Base]?
+    attr_accessor disable_host_prefix (): bool?
+    attr_accessor disable_request_compression (): bool?
+    attr_accessor endpoint (): String?
+    attr_accessor endpoint_resolver (): Hearth::_EndpointResolver[Endpoint::Params]?
+    attr_accessor http2_client (): Hearth::HTTP2::Client?
+    attr_accessor http_api_key_provider (): Hearth::IdentityProvider?
+    attr_accessor http_bearer_provider (): Hearth::IdentityProvider?
+    attr_accessor http_client (): Hearth::HTTP::Client?
+    attr_accessor http_custom_key_provider (): Hearth::IdentityProvider?
+    attr_accessor http_login_provider (): Hearth::IdentityProvider?
+    attr_accessor interceptors (): Hearth::InterceptorList[Config]?
+    attr_accessor logger (): Logger?
+    attr_accessor plugins (): Hearth::PluginList[Config]?
+    attr_accessor request_min_compression_size_bytes (): Integer?
+    attr_accessor retry_strategy (): Hearth::_RetryStrategy?
+    attr_accessor stage (): String?
+    attr_accessor stub_responses (): bool?
+    attr_accessor stubs (): Hearth::Stubs?
+    attr_accessor test_config (): untyped?
+    attr_accessor validate_input (): bool?
 
     def validate!: () -> void
   end
diff --git a/codegen/projections/white_label/sig/white_label/endpoint.rbs b/codegen/projections/white_label/sig/white_label/endpoint.rbs
index 2fa3c8bfc..52035906a 100644
--- a/codegen/projections/white_label/sig/white_label/endpoint.rbs
+++ b/codegen/projections/white_label/sig/white_label/endpoint.rbs
@@ -9,11 +9,12 @@
 
 module WhiteLabel
   module Endpoint
-    class Params < ::Struct[untyped]
-      attr_accessor dataplane: bool
-      attr_accessor resource_url: ::String
-      attr_accessor endpoint: ::String
-      attr_accessor stage: ::String
+    class Params
+      def initialize: (?dataplane: bool?, ?resource_url: ::String?, ?endpoint: ::String?, ?stage: ::String?) -> void
+      attr_accessor dataplane (): bool?
+      attr_accessor resource_url (): ::String?
+      attr_accessor endpoint (): ::String?
+      attr_accessor stage (): ::String?
     end
 
     class Resolver
diff --git a/codegen/projections/white_label/sig/white_label/types.rbs b/codegen/projections/white_label/sig/white_label/types.rbs
index ee56a61a7..b734e4748 100644
--- a/codegen/projections/white_label/sig/white_label/types.rbs
+++ b/codegen/projections/white_label/sig/white_label/types.rbs
@@ -37,22 +37,22 @@ module WhiteLabel
       attr_accessor struct (): Types::Struct?
       attr_accessor un_required_number (): ::Integer?
       attr_accessor un_required_bool (): bool?
-      attr_accessor number (): ::Integer
-      attr_accessor bool (): bool
-      attr_accessor hello (): ::String
-      attr_accessor simple_enum (): ::String
-      attr_accessor valued_enum (): ::String
-      attr_accessor int_enum (): ::Integer
-      attr_accessor null_document (): Hearth::document
-      attr_accessor string_document (): Hearth::document
-      attr_accessor boolean_document (): Hearth::document
-      attr_accessor numbers_document (): Hearth::document
-      attr_accessor list_document (): Hearth::document
-      attr_accessor map_document (): Hearth::document
-      attr_accessor list_of_strings (): ::Array[::String]
-      attr_accessor map_of_strings (): ::Hash[::String, ::String]
-      attr_accessor iso8601_timestamp (): ::Time
-      attr_accessor epoch_timestamp (): ::Time
+      attr_accessor number (): ::Integer?
+      attr_accessor bool (): bool?
+      attr_accessor hello (): ::String?
+      attr_accessor simple_enum (): ::String?
+      attr_accessor valued_enum (): ::String?
+      attr_accessor int_enum (): ::Integer?
+      attr_accessor null_document (): Hearth::document?
+      attr_accessor string_document (): Hearth::document?
+      attr_accessor boolean_document (): Hearth::document?
+      attr_accessor numbers_document (): Hearth::document?
+      attr_accessor list_document (): Hearth::document?
+      attr_accessor map_document (): Hearth::document?
+      attr_accessor list_of_strings (): ::Array[::String]?
+      attr_accessor map_of_strings (): ::Hash[::String, ::String]?
+      attr_accessor iso8601_timestamp (): ::Time?
+      attr_accessor epoch_timestamp (): ::Time?
     end
 
     class DefaultsTestInput
@@ -66,22 +66,22 @@ module WhiteLabel
       attr_accessor struct (): Types::Struct?
       attr_accessor un_required_number (): ::Integer?
       attr_accessor un_required_bool (): bool?
-      attr_accessor number (): ::Integer
-      attr_accessor bool (): bool
-      attr_accessor hello (): ::String
-      attr_accessor simple_enum (): ::String
-      attr_accessor valued_enum (): ::String
-      attr_accessor int_enum (): ::Integer
-      attr_accessor null_document (): Hearth::document
-      attr_accessor string_document (): Hearth::document
-      attr_accessor boolean_document (): Hearth::document
-      attr_accessor numbers_document (): Hearth::document
-      attr_accessor list_document (): Hearth::document
-      attr_accessor map_document (): Hearth::document
-      attr_accessor list_of_strings (): ::Array[::String]
-      attr_accessor map_of_strings (): ::Hash[::String, ::String]
-      attr_accessor iso8601_timestamp (): ::Time
-      attr_accessor epoch_timestamp (): ::Time
+      attr_accessor number (): ::Integer?
+      attr_accessor bool (): bool?
+      attr_accessor hello (): ::String?
+      attr_accessor simple_enum (): ::String?
+      attr_accessor valued_enum (): ::String?
+      attr_accessor int_enum (): ::Integer?
+      attr_accessor null_document (): Hearth::document?
+      attr_accessor string_document (): Hearth::document?
+      attr_accessor boolean_document (): Hearth::document?
+      attr_accessor numbers_document (): Hearth::document?
+      attr_accessor list_document (): Hearth::document?
+      attr_accessor map_document (): Hearth::document?
+      attr_accessor list_of_strings (): ::Array[::String]?
+      attr_accessor map_of_strings (): ::Hash[::String, ::String]?
+      attr_accessor iso8601_timestamp (): ::Time?
+      attr_accessor epoch_timestamp (): ::Time?
     end
 
     class EndpointOperationInput
@@ -94,7 +94,7 @@ module WhiteLabel
 
     class EndpointWithHostLabelOperationInput
       include Hearth::Structure
-      attr_accessor label_member (): ::String
+      attr_accessor label_member (): ::String?
     end
 
     class EndpointWithHostLabelOperationOutput
@@ -277,7 +277,7 @@ module WhiteLabel
 
     class RequestCompressionStreamingInput
       include Hearth::Structure
-      attr_accessor body (): (Hearth::_ReadableIO | Hearth::_WritableIO)
+      attr_accessor body (): (Hearth::_ReadableIO | Hearth::_WritableIO)?
     end
 
     class RequestCompressionStreamingOutput
@@ -286,7 +286,7 @@ module WhiteLabel
 
     class ResourceEndpointInput
       include Hearth::Structure
-      attr_accessor resource_url (): ::String
+      attr_accessor resource_url (): ::String?
     end
 
     class ResourceEndpointOutput
@@ -320,17 +320,17 @@ module WhiteLabel
 
     class StreamingInput
       include Hearth::Structure
-      attr_accessor stream (): (Hearth::_ReadableIO | Hearth::_WritableIO)
+      attr_accessor stream (): (Hearth::_ReadableIO | Hearth::_WritableIO)?
     end
 
     class StreamingOutput
       include Hearth::Structure
-      attr_accessor stream (): (Hearth::_ReadableIO | Hearth::_WritableIO)
+      attr_accessor stream (): (Hearth::_ReadableIO | Hearth::_WritableIO)?
     end
 
     class StreamingWithLengthInput
       include Hearth::Structure
-      attr_accessor stream (): (Hearth::_ReadableIO | Hearth::_WritableIO)
+      attr_accessor stream (): (Hearth::_ReadableIO | Hearth::_WritableIO)?
     end
 
     class StreamingWithLengthOutput
diff --git a/codegen/projections/white_label/spec/auth_spec.rb b/codegen/projections/white_label/spec/auth_spec.rb
index 35f767b89..2996539e8 100644
--- a/codegen/projections/white_label/spec/auth_spec.rb
+++ b/codegen/projections/white_label/spec/auth_spec.rb
@@ -158,7 +158,7 @@ module Auth
   end
 
   describe Config do
-    it 'validates identity resolvers' do
+    it 'validates identity resolvers', rbs_test: :skip do
       msg = /to be in \[Hearth::IdentityProvider\], got String/
       expect do
         Config.new(http_api_key_provider: 'foo').validate!
diff --git a/codegen/projections/white_label/spec/client_spec.rb b/codegen/projections/white_label/spec/client_spec.rb
index 2b27755c6..fa0316de2 100644
--- a/codegen/projections/white_label/spec/client_spec.rb
+++ b/codegen/projections/white_label/spec/client_spec.rb
@@ -19,7 +19,7 @@ module WhiteLabel
       client.kitchen_sink
     end
 
-    it 'validates config' do
+    it 'validates config', rbs_test: :skip do
       expect do
         Client.new(stub_responses: 'false')
       end.to raise_error(ArgumentError, /config\[:stub_responses\]/)
@@ -34,7 +34,7 @@ module WhiteLabel
         expect(client.config.logger).to eq(logger)
       end
 
-      it 'validates global config values' do
+      it 'validates global config values', rbs_test: :skip do
         Hearth.config[:logger] = 'logger'
         expect do
           Client.new
@@ -50,7 +50,7 @@ module WhiteLabel
     end
 
     context 'operation overrides' do
-      it 'validates config' do
+      it 'validates config', rbs_test: :skip do
         expect do
           client.kitchen_sink({}, endpoint: 1)
         end.to raise_error(ArgumentError, /config\[:endpoint\]/)
diff --git a/codegen/projections/white_label/spec/compression_spec.rb b/codegen/projections/white_label/spec/compression_spec.rb
index 163e27ae6..60345383b 100644
--- a/codegen/projections/white_label/spec/compression_spec.rb
+++ b/codegen/projections/white_label/spec/compression_spec.rb
@@ -5,7 +5,7 @@
 module WhiteLabel
   describe Config do
     context 'disable_request_compression' do
-      it 'raises error when given an invalid input' do
+      it 'raises when given an invalid input', rbs_test: :skip do
         expect { Config.new(disable_request_compression: 'string').validate! }
           .to raise_error(
             ArgumentError,
@@ -16,7 +16,7 @@ module WhiteLabel
     end
 
     context 'request_min_compression_size_bytes' do
-      it 'raises error when given invalid integer' do
+      it 'raises when given invalid integer' do
         expect { Config.new(request_min_compression_size_bytes: -1).validate! }
           .to raise_error(
             ArgumentError,
diff --git a/codegen/projections/white_label/spec/config_spec.rb b/codegen/projections/white_label/spec/config_spec.rb
index ea029ace1..a4a5497ec 100644
--- a/codegen/projections/white_label/spec/config_spec.rb
+++ b/codegen/projections/white_label/spec/config_spec.rb
@@ -31,7 +31,7 @@ module WhiteLabel
         expect(config.request_min_compression_size_bytes).to be_a(Integer)
       end
 
-      it 'validates types' do
+      it 'validates types', rbs_test: :skip do
         config = Config.new(logger: 'foo')
         expect { config.validate! }
           .to raise_error(ArgumentError, /config\[:logger\]/)
@@ -39,7 +39,7 @@ module WhiteLabel
 
       it 'raises on unknown keys' do
         expect { Config.new(foo: 'bar') }
-          .to raise_error(ArgumentError, /unknown keywords: foo/)
+          .to raise_error(ArgumentError, /config\[:foo\]/)
       end
     end
   end
diff --git a/codegen/projections/white_label/spec/endpoint_spec.rb b/codegen/projections/white_label/spec/endpoint_spec.rb
index 584341383..cda2fddab 100644
--- a/codegen/projections/white_label/spec/endpoint_spec.rb
+++ b/codegen/projections/white_label/spec/endpoint_spec.rb
@@ -28,7 +28,8 @@ module Endpoint
           endpoint = subject.resolve(params)
           expect(endpoint.uri).to eq(expected[:url])
           expect(endpoint.headers).to eq(expected[:headers])
-          expect(endpoint.auth_schemes).to eq(expected[:auth_schemes])
+          expect(endpoint.auth_schemes.map(&:scheme_id)).to eq(expected[:auth_schemes].map(&:scheme_id))
+          expect(endpoint.auth_schemes.map(&:properties)).to eq(expected[:auth_schemes].map(&:properties))
         end
 
         it 'produces the correct output from the client when calling endpoint_operation' do
@@ -67,7 +68,8 @@ module Endpoint
           endpoint = subject.resolve(params)
           expect(endpoint.uri).to eq(expected[:url])
           expect(endpoint.headers).to eq(expected[:headers])
-          expect(endpoint.auth_schemes).to eq(expected[:auth_schemes])
+          expect(endpoint.auth_schemes.map(&:scheme_id)).to eq(expected[:auth_schemes].map(&:scheme_id))
+          expect(endpoint.auth_schemes.map(&:properties)).to eq(expected[:auth_schemes].map(&:properties))
         end
       end
 
@@ -98,7 +100,8 @@ module Endpoint
           endpoint = subject.resolve(params)
           expect(endpoint.uri).to eq(expected[:url])
           expect(endpoint.headers).to eq(expected[:headers])
-          expect(endpoint.auth_schemes).to eq(expected[:auth_schemes])
+          expect(endpoint.auth_schemes.map(&:scheme_id)).to eq(expected[:auth_schemes].map(&:scheme_id))
+          expect(endpoint.auth_schemes.map(&:properties)).to eq(expected[:auth_schemes].map(&:properties))
         end
 
         it 'produces the correct output from the client when calling endpoint_operation' do
@@ -136,7 +139,8 @@ module Endpoint
           endpoint = subject.resolve(params)
           expect(endpoint.uri).to eq(expected[:url])
           expect(endpoint.headers).to eq(expected[:headers])
-          expect(endpoint.auth_schemes).to eq(expected[:auth_schemes])
+          expect(endpoint.auth_schemes.map(&:scheme_id)).to eq(expected[:auth_schemes].map(&:scheme_id))
+          expect(endpoint.auth_schemes.map(&:properties)).to eq(expected[:auth_schemes].map(&:properties))
         end
 
         it 'produces the correct output from the client when calling resource_endpoint' do
@@ -176,7 +180,8 @@ module Endpoint
           endpoint = subject.resolve(params)
           expect(endpoint.uri).to eq(expected[:url])
           expect(endpoint.headers).to eq(expected[:headers])
-          expect(endpoint.auth_schemes).to eq(expected[:auth_schemes])
+          expect(endpoint.auth_schemes.map(&:scheme_id)).to eq(expected[:auth_schemes].map(&:scheme_id))
+          expect(endpoint.auth_schemes.map(&:properties)).to eq(expected[:auth_schemes].map(&:properties))
         end
 
         it 'produces the correct output from the client when calling dataplane_endpoint' do
diff --git a/codegen/smithy-ruby-codegen-test-utils/src/main/java/software/amazon/smithy/ruby/codegen/integrations/WhiteLabelTestIntegration.java b/codegen/smithy-ruby-codegen-test-utils/src/main/java/software/amazon/smithy/ruby/codegen/integrations/WhiteLabelTestIntegration.java
index f955344ac..e159863ad 100644
--- a/codegen/smithy-ruby-codegen-test-utils/src/main/java/software/amazon/smithy/ruby/codegen/integrations/WhiteLabelTestIntegration.java
+++ b/codegen/smithy-ruby-codegen-test-utils/src/main/java/software/amazon/smithy/ruby/codegen/integrations/WhiteLabelTestIntegration.java
@@ -117,6 +117,7 @@ public List<AuthScheme> getAdditionalAuthSchemes(GenerationContext context) {
                                 identityType,
                                 HttpBasicAuthTrait.ID))
                 .documentationType(Hearth.IDENTITY_PROVIDER.toString())
+                .rbsType(Hearth.IDENTITY_PROVIDER.toString())
                 .defaultDynamicValue(defaultConfigValue)
                 .constraint(new TypeConstraint(Hearth.IDENTITY_PROVIDER.toString()))
                 .build();
diff --git a/codegen/smithy-ruby-codegen-test/integration-specs/auth_spec.rb b/codegen/smithy-ruby-codegen-test/integration-specs/auth_spec.rb
index 35f767b89..2996539e8 100644
--- a/codegen/smithy-ruby-codegen-test/integration-specs/auth_spec.rb
+++ b/codegen/smithy-ruby-codegen-test/integration-specs/auth_spec.rb
@@ -158,7 +158,7 @@ module Auth
   end
 
   describe Config do
-    it 'validates identity resolvers' do
+    it 'validates identity resolvers', rbs_test: :skip do
       msg = /to be in \[Hearth::IdentityProvider\], got String/
       expect do
         Config.new(http_api_key_provider: 'foo').validate!
diff --git a/codegen/smithy-ruby-codegen-test/integration-specs/client_spec.rb b/codegen/smithy-ruby-codegen-test/integration-specs/client_spec.rb
index 2b27755c6..fa0316de2 100644
--- a/codegen/smithy-ruby-codegen-test/integration-specs/client_spec.rb
+++ b/codegen/smithy-ruby-codegen-test/integration-specs/client_spec.rb
@@ -19,7 +19,7 @@ module WhiteLabel
       client.kitchen_sink
     end
 
-    it 'validates config' do
+    it 'validates config', rbs_test: :skip do
       expect do
         Client.new(stub_responses: 'false')
       end.to raise_error(ArgumentError, /config\[:stub_responses\]/)
@@ -34,7 +34,7 @@ module WhiteLabel
         expect(client.config.logger).to eq(logger)
       end
 
-      it 'validates global config values' do
+      it 'validates global config values', rbs_test: :skip do
         Hearth.config[:logger] = 'logger'
         expect do
           Client.new
@@ -50,7 +50,7 @@ module WhiteLabel
     end
 
     context 'operation overrides' do
-      it 'validates config' do
+      it 'validates config', rbs_test: :skip do
         expect do
           client.kitchen_sink({}, endpoint: 1)
         end.to raise_error(ArgumentError, /config\[:endpoint\]/)
diff --git a/codegen/smithy-ruby-codegen-test/integration-specs/compression_spec.rb b/codegen/smithy-ruby-codegen-test/integration-specs/compression_spec.rb
index 163e27ae6..60345383b 100644
--- a/codegen/smithy-ruby-codegen-test/integration-specs/compression_spec.rb
+++ b/codegen/smithy-ruby-codegen-test/integration-specs/compression_spec.rb
@@ -5,7 +5,7 @@
 module WhiteLabel
   describe Config do
     context 'disable_request_compression' do
-      it 'raises error when given an invalid input' do
+      it 'raises when given an invalid input', rbs_test: :skip do
         expect { Config.new(disable_request_compression: 'string').validate! }
           .to raise_error(
             ArgumentError,
@@ -16,7 +16,7 @@ module WhiteLabel
     end
 
     context 'request_min_compression_size_bytes' do
-      it 'raises error when given invalid integer' do
+      it 'raises when given invalid integer' do
         expect { Config.new(request_min_compression_size_bytes: -1).validate! }
           .to raise_error(
             ArgumentError,
diff --git a/codegen/smithy-ruby-codegen-test/integration-specs/config_spec.rb b/codegen/smithy-ruby-codegen-test/integration-specs/config_spec.rb
index ea029ace1..a4a5497ec 100644
--- a/codegen/smithy-ruby-codegen-test/integration-specs/config_spec.rb
+++ b/codegen/smithy-ruby-codegen-test/integration-specs/config_spec.rb
@@ -31,7 +31,7 @@ module WhiteLabel
         expect(config.request_min_compression_size_bytes).to be_a(Integer)
       end
 
-      it 'validates types' do
+      it 'validates types', rbs_test: :skip do
         config = Config.new(logger: 'foo')
         expect { config.validate! }
           .to raise_error(ArgumentError, /config\[:logger\]/)
@@ -39,7 +39,7 @@ module WhiteLabel
 
       it 'raises on unknown keys' do
         expect { Config.new(foo: 'bar') }
-          .to raise_error(ArgumentError, /unknown keywords: foo/)
+          .to raise_error(ArgumentError, /config\[:foo\]/)
       end
     end
   end
diff --git a/codegen/smithy-ruby-codegen/CHANGELOG.md b/codegen/smithy-ruby-codegen/CHANGELOG.md
index 5a0e4ef77..d04a7af7b 100644
--- a/codegen/smithy-ruby-codegen/CHANGELOG.md
+++ b/codegen/smithy-ruby-codegen/CHANGELOG.md
@@ -1,7 +1,8 @@
 Unreleased Changes
 ------------------
 
-* Issue - Remove `Struct` from generated Types.
+* Issue - Add `to_s` to `Structure`.
+* Issue - Remove `Struct` from generated Types, Config, and other places to allow for better RBS typing as well as less reserved words.
 * Feature - Add support for stringArray Endpoint parameters + operationContextParams binding.
 * Issue - Update reserved member names for new Struct methods.
 * Feature - Add support for Smithy RPC v2 CBOR protocol.
diff --git a/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/AuthGenerator.java b/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/AuthGenerator.java
index c49e412f1..0a5f3e43d 100644
--- a/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/AuthGenerator.java
+++ b/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/AuthGenerator.java
@@ -98,15 +98,32 @@ public void renderRbs() {
     }
 
     private void renderAuthParamsClass(RubyCodeWriter writer) {
-        writer.write("Params = Struct.new($L, keyword_init: true)",
-                context.getAuthParams().stream()
+        writer
+                .openBlock("class Params")
+                .openBlock("def initialize($L)", context.getAuthParams().stream()
+                        .map(p -> "%s: nil".formatted(RubyFormatter.toSnakeCase(p.getName())))
+                        .collect(Collectors.joining(", ")))
+                .call(() -> {
+                    context.getAuthParams().forEach(p -> {
+                        String authParam = RubyFormatter.toSnakeCase(p.getName());
+                        writer.write("@$L = $L", authParam, authParam);
+                    });
+                })
+                .closeBlock("end")
+                .write("")
+                .write("attr_accessor $L", context.getAuthParams().stream()
                         .map(p -> RubyFormatter.asSymbol(p.getName()))
-                        .collect(Collectors.joining(", ")));
+                        .collect(Collectors.joining(", ")))
+                .closeBlock("end");
     }
 
     private void renderRbsAuthParamsClass(RubyCodeWriter writer) {
         writer
-                .openBlock("class Params < ::Struct[untyped]")
+                .openBlock("class Params")
+                .write("def initialize: ($L) -> void",
+                        context.getAuthParams().stream()
+                                .map(p -> "?%s: %s?".formatted(p.getName(), p.getRbsType()))
+                                .collect(Collectors.joining(", ")))
                 .call(() -> {
                     context.getAuthParams().forEach(p -> {
                         writer.write("attr_accessor $L (): $L", p.getName(), p.getRbsType());
diff --git a/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/ConfigGenerator.java b/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/ConfigGenerator.java
index 4af31c737..85d6c9cfa 100644
--- a/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/ConfigGenerator.java
+++ b/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/ConfigGenerator.java
@@ -51,28 +51,36 @@ protected String getModule() {
 
     public void render() {
         write(writer -> {
-            String membersBlock = "nil";
+            String membersBlock;
             if (!clientConfigList.isEmpty()) {
                 membersBlock = clientConfigList
                         .stream()
-                        .map(clientConfig -> RubyFormatter.asSymbol(
-                                RubySymbolProvider.toMemberName(clientConfig.getName())))
-                        .collect(Collectors.joining(",\n"));
+                        .map(clientConfig -> RubySymbolProvider.toMemberName(clientConfig.getName()))
+                        .collect(Collectors.joining("\n"));
+            } else {
+                membersBlock = "";
             }
-            membersBlock += ",";
 
             writer
                     .preamble()
                     .includeRequires()
                     .openBlock("module $L", settings.getModule())
                     .call(() -> renderConfigDocumentation(writer))
-                    .openBlock("Config = ::Struct.new(")
-                    .write(membersBlock)
-                    .write("keyword_init: true")
-                    .closeBlock(") do")
-                    .indent()
+                    .openBlock("class Config")
                     .write("include $T", Hearth.CONFIGURATION)
                     .write("")
+                    .call(() -> {
+                        if (membersBlock.isBlank()) {
+                            writer.write("MEMBERS = [].freeze");
+                        } else {
+                            writer.openBlock("MEMBERS = %i[");
+                            writer.write(membersBlock);
+                            writer.closeBlock("].freeze");
+                        }
+                    })
+                    .write("")
+                    .write("attr_accessor(*MEMBERS)")
+                    .write("")
                     .call(() -> renderValidateMethod(writer))
                     .write("\nprivate\n")
                     .call(() -> renderDefaultsMethod(writer))
@@ -89,14 +97,13 @@ public void renderRbs() {
         writeRbs(writer -> {
             writer
                     .openBlock("module $L", settings.getModule())
-                    .openBlock("class Config < ::Struct[untyped]")
+                    .openBlock("class Config")
                     .write("include $T[instance]", Hearth.CONFIGURATION)
-                    .write("")
                     .call(() -> {
                         clientConfigList.forEach((clientConfig) -> {
                             String member = RubySymbolProvider.toMemberName(clientConfig.getName());
                             String rbsType = clientConfig.getRbsType();
-                            writer.write("attr_accessor $L (): $L", member, rbsType);
+                            writer.write("attr_accessor $L (): $L?", member, rbsType);
                         });
                     })
                     .write("")
diff --git a/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/EndpointGenerator.java b/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/EndpointGenerator.java
index 5f696f418..8cd08a7a4 100644
--- a/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/EndpointGenerator.java
+++ b/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/EndpointGenerator.java
@@ -230,7 +230,7 @@ private void renderEndpointParamsClass(RubyCodeWriter writer) {
         Map<String, String> defaultParams = new LinkedHashMap<>();
         endpointRuleSet.getParameters().forEach((parameter -> {
             String rubyParamName = RubyFormatter.toSnakeCase(parameter.getName().getName().getValue());
-            params.add(RubyFormatter.asSymbol(rubyParamName));
+            params.add(rubyParamName);
             if (parameter.getDefault().isPresent()) {
                 if (parameter.getType() == ParameterType.STRING) {
                     defaultParams.put(rubyParamName,
@@ -250,29 +250,26 @@ private void renderEndpointParamsClass(RubyCodeWriter writer) {
         }));
 
         writer
-                .openBlock("Params = ::Struct.new(")
-                .write(String.join(",\n", params) + ", ")
-                .write("keyword_init: true")
-                .closeBlock(") do")
-                .indent()
-                .write("include $T", Hearth.STRUCTURE)
+                .openBlock("class Params")
+                .openBlock("def initialize($L)", params.stream()
+                        .map(p -> "%s: nil".formatted(RubyFormatter.toSnakeCase(p)))
+                        .collect(Collectors.joining(", ")))
                 .call(() -> {
-                    if (!defaultParams.isEmpty()) {
-                        writer
-                                .write("")
-                                .openBlock("def initialize(*)")
-                                .write("super")
-                                .call(() -> {
-                                    defaultParams.forEach((param, defaultValue) -> {
-                                        writer.write("self.$1L = $2L if self.$1L.nil?",
-                                                param,
-                                                defaultValue);
-                                    });
-                                })
-                                .closeBlock("end");
-                    }
-
+                    params.forEach(p -> {
+                        String endpointParam = RubyFormatter.toSnakeCase(p);
+                        if (defaultParams.containsKey(endpointParam)) {
+                            writer.write("@$1L = $1L.nil? ? $2L : $1L",
+                                    endpointParam, defaultParams.get(endpointParam));
+                        } else {
+                            writer.write("@$L = $L", endpointParam, endpointParam);
+                        }
+                    });
                 })
+                .closeBlock("end")
+                .write("")
+                .write("attr_accessor $L", params.stream()
+                        .map(p -> RubyFormatter.asSymbol(p))
+                        .collect(Collectors.joining(", ")))
                 .closeBlock("end");
     }
 
@@ -292,10 +289,14 @@ private void renderRbsEndpointParamsClass(RubyCodeWriter writer) {
         }));
 
         writer
-                .openBlock("class Params < ::Struct[untyped]")
+                .openBlock("class Params")
+                .write("def initialize: ($L) -> void",
+                        paramsToTypes.entrySet().stream()
+                                .map(e -> "?%s: %s?".formatted(e.getKey(), e.getValue()))
+                                .collect(Collectors.joining(", ")))
                 .call(() -> {
                     paramsToTypes.forEach((param, rbsType) -> {
-                        writer.write("attr_accessor $L: $L", param, rbsType);
+                        writer.write("attr_accessor $L (): $L?", param, rbsType);
                     });
                 })
                 .closeBlock("end");
@@ -518,7 +519,10 @@ private void renderEndpointTestCases(RubyCodeWriter writer, List<EndpointTestCas
                                     .write("endpoint = subject.resolve(params)")
                                     .write("expect(endpoint.uri).to eq(expected[:url])")
                                     .write("expect(endpoint.headers).to eq(expected[:headers])")
-                                    .write("expect(endpoint.auth_schemes).to eq(expected[:auth_schemes])");
+                                    .write("expect(endpoint.auth_schemes.map(&:scheme_id)).to "
+                                            + "eq(expected[:auth_schemes].map(&:scheme_id))")
+                                    .write("expect(endpoint.auth_schemes.map(&:properties)).to "
+                                            + "eq(expected[:auth_schemes].map(&:properties))");
                         }
                     })
                     .closeBlock("end") // end main test case it block
diff --git a/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/GlobalConfigPluginGenerator.java b/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/GlobalConfigPluginGenerator.java
index b52c5e398..6f8560ce1 100644
--- a/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/GlobalConfigPluginGenerator.java
+++ b/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/GlobalConfigPluginGenerator.java
@@ -75,7 +75,7 @@ private void renderCallMethod(RubyCodeWriter writer) {
                 .openBlock("def call(config)")
                 .write("options = config.options")
                 .openBlock("$T.config.each do |key, value|", Hearth.HEARTH)
-                .write("config[key] = value unless options.key?(key)")
+                .write("config.send(\"#{key}=\", value) unless options.key?(key)")
                 .closeBlock("end")
                 .closeBlock("end");
     }
diff --git a/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/HttpProtocolTestGenerator.java b/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/HttpProtocolTestGenerator.java
index d53d31141..cbbccf4c0 100644
--- a/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/HttpProtocolTestGenerator.java
+++ b/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/HttpProtocolTestGenerator.java
@@ -180,7 +180,7 @@ private void renderResponseStubberTests(OperationShape operation,
             writer
                     .write("")
                     .writeDocstring(documentation)
-                    .openBlock("it 'stubs $L'$L$L do", testCase.getId(),
+                    .openBlock("it '$L'$L$L do", testCase.getId(),
                             skipTest(operation, testCase.getId(), "response"), skipRbsTest(outputShape))
                     .call(() -> renderResponseStubInterceptor(testCase))
                     .write("interceptor = $T.new(read_after_transmit: proc)", Hearth.INTERCEPTOR)
diff --git a/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/types/StructureGenerator.java b/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/types/StructureGenerator.java
index eca3a953b..996e86f9f 100644
--- a/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/types/StructureGenerator.java
+++ b/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/types/StructureGenerator.java
@@ -26,7 +26,6 @@
 import software.amazon.smithy.model.shapes.Shape;
 import software.amazon.smithy.model.shapes.ShapeVisitor;
 import software.amazon.smithy.model.shapes.StructureShape;
-import software.amazon.smithy.model.traits.RequiredTrait;
 import software.amazon.smithy.model.traits.SensitiveTrait;
 import software.amazon.smithy.ruby.codegen.GenerationContext;
 import software.amazon.smithy.ruby.codegen.Hearth;
@@ -103,8 +102,7 @@ public void render() {
                             Shape target = model.expectShape(memberShape.getTarget());
                             Symbol symbol = symbolProvider.toSymbol(target);
                             String rbsType = symbol.getProperty("rbsType").get().toString();
-                            String required = memberShape.hasTrait(RequiredTrait.class) ? "" : "?";
-                            writer.write("attr_accessor $L (): $L$L", memberName, rbsType, required);
+                            writer.write("attr_accessor $L (): $L?", memberName, rbsType);
                         });
                     })
                     .closeBlock("end");
@@ -191,25 +189,29 @@ private void renderToSMethod(RubyCodeWriter writer) {
 
             writer
                     .openBlock("\ndef to_s")
-                    .write("\"#<$L \"\\", fullQualifiedShapeName)
+                    .write("'#<$L ' \\", fullQualifiedShapeName)
                     .indent();
 
             while (iterator.hasNext()) {
                 MemberShape memberShape = iterator.next();
                 String key = symbolProvider.toMemberName(memberShape);
                 String value = "#{" + key + " || 'nil'}";
+                boolean memberLiteral = false;
 
                 if (memberShape.isBlobShape() || memberShape.isStringShape()) {
                     // Strings are wrapped in quotes
                     value = "\"" + value + "\"";
+                    memberLiteral = true;
                 } else if (memberShape.getMemberTrait(model, SensitiveTrait.class).isPresent()) {
-                    value = "\\\"[SENSITIVE]\\\"";
+                    value = "[SENSITIVE]";
+                    memberLiteral = true;
                 }
 
+                String quote = memberLiteral ? "'" : "\"";
                 if (iterator.hasNext()) {
-                    writer.write("\"$L=$L, \"\\", key, value);
+                    writer.write("$3L$1L=$2L, $3L \\", key, value, quote);
                 } else {
-                    writer.write("\"$L=$L>\"", key, value);
+                    writer.write("$3L$1L=$2L>$3L", key, value, quote);
                 }
             }
             writer
diff --git a/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/types/UnionGenerator.java b/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/types/UnionGenerator.java
index bda9accfa..df0bb69a8 100644
--- a/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/types/UnionGenerator.java
+++ b/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/types/UnionGenerator.java
@@ -112,19 +112,17 @@ public void render() {
     }
 
     private void renderUnionToSMethod(RubyCodeWriter writer, MemberShape memberShape) {
-        String fullQualifiedShapeName = settings.getModule() + "::Types::"
-                + symbolProvider.toMemberName(memberShape);
-
-        writer.write("")
-                .openBlock("def to_s");
-
-        if (memberShape.getMemberTrait(model, SensitiveTrait.class).isPresent()) {
-            writer.write("\"#<$L [SENSITIVE]>\"", fullQualifiedShapeName);
-        } else {
-            writer.write("\"#<$L #{__getobj__ || 'nil'}>\"", fullQualifiedShapeName);
+        if (!memberShape.getMemberTrait(model, SensitiveTrait.class).isPresent()) {
+            return;
         }
 
-        writer.closeBlock("end");
+        String fullQualifiedShapeName = settings.getModule() + "::Types::"
+                + symbolProvider.toMemberName(memberShape);
+        writer
+                .write("")
+                .openBlock("def to_s")
+                .write("\"#<$L [SENSITIVE]>\"", fullQualifiedShapeName)
+                .closeBlock("end");
     }
 
     private class UnionToHValueRbsVisitor extends ShapeVisitor.Default<String> {
diff --git a/hearth/CHANGELOG.md b/hearth/CHANGELOG.md
index 7c035b433..eb8dc58d5 100644
--- a/hearth/CHANGELOG.md
+++ b/hearth/CHANGELOG.md
@@ -1,7 +1,7 @@
 Unreleased Changes
 ------------------
 
-* Issue - Remove `Struct` from generated Types.
+* Issue - Remove `Struct` from generated Types, Config, and other places to allow for better RBS typing as well as less reserved words.
 * Feature - Add `Hearth::Cbor.encode` and `Hearth::Cbor.decode`.
 * Issue - Fix query param `to_s` for empty arrays.
 * Feature - [Breaking Change] Add `config` to `Hearth::Context` and refactor `logger` and `interceptors` inside of it.
diff --git a/hearth/lib/hearth/cbor.rb b/hearth/lib/hearth/cbor.rb
index 754bc8ba6..bd8a26379 100644
--- a/hearth/lib/hearth/cbor.rb
+++ b/hearth/lib/hearth/cbor.rb
@@ -13,16 +13,22 @@ module CBOR
     # A Tag consists of a tag number and a value.
     # In the extended generic data model, a tag number's definition
     # describes the additional semantics conveyed with the tag number.
-    # # @!method initialize(*args)
-    #   @option args [Integer] :tag The tag number.
-    #   @option args [Object] :value The tag's content.
-    # @!attribute tag
-    #   The tag number.
-    #   @return [Integer]
-    # @!attribute value
-    #   The tag's content.
-    #   @return [Object]
-    Tagged = Struct.new(:tag, :value)
+    class Tagged
+      # @param [Integer] :tag The tag number.
+      # @param [Object] :value The tag's content.
+      def initialize(tag:, value:)
+        @tag = tag
+        @value = value
+      end
+
+      # The tag number.
+      # @return [Integer]
+      attr_accessor :tag
+
+      # The tag's content.
+      # @return [Object]
+      attr_accessor :value
+    end
 
     # Generic Cbor error, super class for specific encode/decode related errors.
     class Error < StandardError; end
diff --git a/hearth/lib/hearth/cbor/decoder.rb b/hearth/lib/hearth/cbor/decoder.rb
index c60e8cd65..84d1c231c 100644
--- a/hearth/lib/hearth/cbor/decoder.rb
+++ b/hearth/lib/hearth/cbor/decoder.rb
@@ -72,7 +72,7 @@ def decode_item
           when TAG_TYPE_BIGDEC
             read_big_decimal
           else
-            Tagged.new(tag, decode_item)
+            Tagged.new(tag: tag, value: decode_item)
           end
         when :break_stop_code
           raise UnexpectedBreakCodeError
diff --git a/hearth/lib/hearth/config/resolver.rb b/hearth/lib/hearth/config/resolver.rb
index 9fa528c43..1771f55c5 100644
--- a/hearth/lib/hearth/config/resolver.rb
+++ b/hearth/lib/hearth/config/resolver.rb
@@ -7,10 +7,10 @@ module Config
     class Resolver
       private_class_method :new
 
-      # @param config [Struct]
+      # @param config [Configuration]
       # @param options [Hash]
       # @param defaults [Hash<Array<Proc>>]
-      # @return [Struct]
+      # @return [Configuration]
       def self.resolve(config, options, defaults = {})
         new(config).send(:resolve, options, defaults)
       end
@@ -30,8 +30,8 @@ def initialize(config)
       def resolve(options, defaults)
         @options = options
         @defaults = defaults
-        @config.members.each do |key|
-          @config[key] = self[key]
+        @config.class::MEMBERS.each do |key|
+          @config.send("#{key}=", self[key])
         end
       end
 
diff --git a/hearth/lib/hearth/configuration.rb b/hearth/lib/hearth/configuration.rb
index 3df757abc..998f7577f 100644
--- a/hearth/lib/hearth/configuration.rb
+++ b/hearth/lib/hearth/configuration.rb
@@ -5,13 +5,21 @@ module Hearth
   module Configuration
     def initialize(**options)
       @options = options.dup
+      Hearth::Validator.validate_unknown!(self, options, context: 'config')
       Hearth::Config::Resolver.resolve(self, options, _defaults)
-      super
     end
 
     # @return [Hash<Symbol, Object>] The original configuration options.
     attr_reader :options
 
+    # @return [Hash<Symbol, Object>] The configuration options.
+    def to_h(obj = self)
+      obj.class::MEMBERS.each_with_object({}) do |member, hash|
+        hash[member] = obj.send(member)
+      end
+    end
+    alias to_hash to_h
+
     def merge(configuration)
       self.class.new(**to_h.merge(configuration.to_h))
     end
diff --git a/hearth/lib/hearth/dns/host_address.rb b/hearth/lib/hearth/dns/host_address.rb
index b175fac19..7d931455f 100644
--- a/hearth/lib/hearth/dns/host_address.rb
+++ b/hearth/lib/hearth/dns/host_address.rb
@@ -3,25 +3,28 @@
 module Hearth
   module DNS
     # Address results from a DNS lookup in {HostResolver}.
-    # @!method initialize(*args)
-    #   @option args [Symbol] :address_type The type of address. For example,
-    #    :A or :AAAA.
-    #   @option args [String] :address The IP address.
-    #   @option args [String] :hostname The hostname that was resolved.
-    # @!attribute address_type
-    #   The type of address. For example, :A or :AAAA.
-    #   @return [Symbol]
-    # @!attribute address
-    #   The IP address.
-    #   @return [String]
-    # @!attribute hostname
-    #   The hostname that was resolved.
-    #   @return [String]
-    HostAddress = Struct.new(
-      :address_type,
-      :address,
-      :hostname,
-      keyword_init: true
-    )
+    class HostAddress
+      # @param [Symbol] :address_type The type of address. For example,
+      #  :A or :AAAA.
+      # @param [String] :address The IP address.
+      # @param [String] :hostname The hostname that was resolved.
+      def initialize(address_type:, address:, hostname:)
+        @address_type = address_type
+        @address = address
+        @hostname = hostname
+      end
+
+      # The type of address. For example, :A or :AAAA.
+      # @return [Symbol]
+      attr_accessor :address_type
+
+      # The IP address.
+      # @return [String]
+      attr_accessor :address
+
+      # The hostname that was resolved.
+      # @return [String]
+      attr_accessor :hostname
+    end
   end
 end
diff --git a/hearth/lib/hearth/endpoint_rules.rb b/hearth/lib/hearth/endpoint_rules.rb
index 6044812d4..2cb9d420f 100644
--- a/hearth/lib/hearth/endpoint_rules.rb
+++ b/hearth/lib/hearth/endpoint_rules.rb
@@ -11,49 +11,45 @@ module Hearth
   # invoked without additional dependencies, called the standard library.
   module EndpointRules
     # An Authentication Scheme supported by an Endpoint
-    # @!attribute scheme_id
-    #   The identifier of the authentication scheme.
-    #   @return [String]
-    # @!attribute properties
-    #   Additional properties of the authentication scheme.
-    #   @return [Hash]
-    AuthScheme = Struct.new(
-      :scheme_id,
-      :properties,
-      keyword_init: true
-    ) do
-      # @option args [String] :scheme_id
-      # @option args [Hash] :properties ({})
-      def initialize(*args)
-        super
-        self.properties ||= {}
+    class AuthScheme
+      # @param [String] :scheme_id
+      # @param [Hash] :properties ({})
+      def initialize(scheme_id:, properties: {})
+        @scheme_id = scheme_id
+        @properties = properties
       end
+
+      # The identifier of the authentication scheme.
+      # @return [String]
+      attr_accessor :scheme_id
+
+      # Additional properties of the authentication scheme.
+      # @return [Hash]
+      attr_accessor :properties
     end
 
     # An Endpoint resolved by an EndpointProvider
-    # @!attribute uri
-    #   The URI of the endpoint.
-    #   @return [String]
-    # @!attribute auth_schemes
-    #   The authentication schemes supported by the endpoint.
-    #   @return [Array<AuthScheme>]
-    # @!attribute headers
-    #   The headers to include in requests to the endpoint.
-    #   @return [Hash]
-    Endpoint = Struct.new(
-      :uri,
-      :auth_schemes,
-      :headers,
-      keyword_init: true
-    ) do
-      # @option args [String] :uri
-      # @option args [Array<AuthScheme>] :auth_schemes ([])
-      # @option args [Hash] :headers ({})
-      def initialize(*args)
-        super
-        self.auth_schemes ||= []
-        self.headers ||= {}
+    class Endpoint
+      # @param [String] :uri
+      # @param [Array<AuthScheme>] :auth_schemes ([])
+      # @param [Hash] :headers ({})
+      def initialize(uri:, auth_schemes: [], headers: {})
+        @uri = uri
+        @auth_schemes = auth_schemes
+        @headers = headers
       end
+
+      # The URI of the endpoint.
+      # @return [String]
+      attr_accessor :uri
+
+      # The authentication schemes supported by the endpoint.
+      # @return [Array<AuthScheme>]
+      attr_accessor :auth_schemes
+
+      # The headers to include in requests to the endpoint.
+      # @return [Hash]
+      attr_accessor :headers
     end
 
     # Evaluates whether the input string is a compliant RFC 1123 host segment.
diff --git a/hearth/lib/hearth/http/client.rb b/hearth/lib/hearth/http/client.rb
index 938d39230..05542a260 100644
--- a/hearth/lib/hearth/http/client.rb
+++ b/hearth/lib/hearth/http/client.rb
@@ -10,7 +10,7 @@ module HTTP
     # An HTTP client that uses Net::HTTP to send requests.
     class Client
       # @api private
-      OPTIONS = {
+      MEMBERS = {
         logger: nil,
         debug_output: nil,
         proxy: nil,
@@ -84,16 +84,16 @@ class Client
       #   optionally other keyword args similar to Addrinfo.getaddrinfo's
       #   positional parameters.
       def initialize(options = {})
-        unknown = options.keys - OPTIONS.keys
+        unknown = options.keys - MEMBERS.keys
         raise ArgumentError, "Unknown options: #{unknown}" unless unknown.empty?
 
-        OPTIONS.each_pair do |opt_name, default_value|
+        MEMBERS.each_pair do |opt_name, default_value|
           value = options.key?(opt_name) ? options[opt_name] : default_value
           instance_variable_set("@#{opt_name}", value)
         end
       end
 
-      OPTIONS.each_key do |attr_name|
+      MEMBERS.each_key do |attr_name|
         attr_reader(attr_name)
       end
 
@@ -254,7 +254,7 @@ def proxy_parts
       # Config options for the HTTP client used for connection pooling
       # @return [Hash]
       def pool_config
-        OPTIONS.each_key.with_object({}) do |option_name, hash|
+        MEMBERS.each_key.with_object({}) do |option_name, hash|
           hash[option_name] = instance_variable_get("@#{option_name}")
         end
       end
diff --git a/hearth/lib/hearth/middleware/auth.rb b/hearth/lib/hearth/middleware/auth.rb
index b1c054911..b350a92f9 100644
--- a/hearth/lib/hearth/middleware/auth.rb
+++ b/hearth/lib/hearth/middleware/auth.rb
@@ -44,14 +44,20 @@ def call(input, context)
 
       private
 
-      ResolvedAuth = Struct.new(
-        :scheme_id,
-        :signer,
-        :signer_properties,
-        :identity,
-        :identity_properties,
-        keyword_init: true
-      )
+      # @api private
+      class ResolvedAuth
+        def initialize(scheme_id:, signer:, signer_properties:,
+                       identity:, identity_properties:)
+          @scheme_id = scheme_id
+          @signer = signer
+          @signer_properties = signer_properties
+          @identity = identity
+          @identity_properties = identity_properties
+        end
+
+        attr_accessor :scheme_id, :signer, :signer_properties,
+                      :identity, :identity_properties
+      end
 
       def resolve_auth(auth_options)
         failures = []
diff --git a/hearth/lib/hearth/retry.rb b/hearth/lib/hearth/retry.rb
index cdfe23c3c..ddc632ec1 100644
--- a/hearth/lib/hearth/retry.rb
+++ b/hearth/lib/hearth/retry.rb
@@ -10,20 +10,19 @@
 module Hearth
   module Retry
     # Represents a token that can be used to retry an operation.
-    # @!attribute retry_count
-    #   The number of times the operation has been retried.
-    #   @return [Integer]
-    # @!attribute retry_delay
-    #   The delay before the next retry.
-    #   @return [Numeric]
-    Token = Struct.new(:retry_count, :retry_delay, keyword_init: true) do
-      # @option args [Integer] :retry_count (0)
-      # @option args [Numeric] :retry_delay (0)
-      def initialize(*args)
-        super
-        self.retry_count ||= 0
-        self.retry_delay ||= 0
+    class Token
+      def initialize(retry_count: 0, retry_delay: 0)
+        @retry_count = retry_count
+        @retry_delay = retry_delay
       end
+
+      # The number of times the operation has been retried.
+      # @return [Integer]
+      attr_accessor :retry_count
+
+      # The delay before the next retry.
+      # @return [Numeric]
+      attr_accessor :retry_delay
     end
   end
 end
diff --git a/hearth/lib/hearth/structure.rb b/hearth/lib/hearth/structure.rb
index a6b2efec3..1ab2db4a9 100644
--- a/hearth/lib/hearth/structure.rb
+++ b/hearth/lib/hearth/structure.rb
@@ -23,7 +23,7 @@ def initialize(options = {})
     # Deeply converts the Struct into a hash. Structure members that
     # are `nil` are omitted from the resultant hash.
     #
-    # @return [Hash, Structure, Object]
+    # @return [Hash, Structure]
     def to_h(obj = self)
       case obj
       when Union
@@ -40,6 +40,23 @@ def to_h(obj = self)
     end
     alias to_hash to_h
 
+    # Returns a string representation of the Structure.
+    def to_s(obj = self)
+      case obj
+      when Union
+        "#<#{obj.class.name} #{obj.__getobj__ || 'nil'}>"
+      when Structure
+        _to_s_structure(obj)
+      when Hash
+        _to_s_hash(obj).to_s
+      when Array
+        _to_s_array(obj).to_s
+      else
+        obj.to_s
+      end
+    end
+    alias to_string to_s
+
     private
 
     def _to_h_structure(obj)
@@ -58,5 +75,23 @@ def _to_h_hash(obj)
     def _to_h_array(obj)
       obj.collect { |value| to_hash(value) }
     end
+
+    def _to_s_structure(obj)
+      members = obj.class::MEMBERS.map do |member|
+        value = to_string(obj.send(member))
+        " #{member}=#{value.empty? ? 'nil' : value}"
+      end
+      "#<#{self.class.name}#{members.join(',')}>"
+    end
+
+    def _to_s_hash(obj)
+      obj.transform_values do |value|
+        to_string(value)
+      end
+    end
+
+    def _to_s_array(obj)
+      obj.collect { |value| to_string(value) }
+    end
   end
 end
diff --git a/hearth/lib/hearth/validator.rb b/hearth/lib/hearth/validator.rb
index 90bad2201..7b4ae2be5 100755
--- a/hearth/lib/hearth/validator.rb
+++ b/hearth/lib/hearth/validator.rb
@@ -59,12 +59,12 @@ def self.validate_types!(value, *types, context:)
     end
 
     # Validate unknown parameters are not present for a given Type.
-    # @param type [Structure] The Type to validate against.
+    # @param klass [Structure, Configuration] The class to validate against.
     # @param params [Hash] The parameters to validate.
     # @param context [String] The context of the value being validated.
     # @raise [ArgumentError] Raises when unknown parameters are present.
-    def self.validate_unknown!(type, params, context:)
-      unknown = params.keys - type.class::MEMBERS
+    def self.validate_unknown!(klass, params, context:)
+      unknown = params.keys - klass.class::MEMBERS
       return if unknown.empty?
 
       unknown = unknown.map { |key| "#{context}[:#{key}]" }
diff --git a/hearth/sig/lib/hearth/configuration.rbs b/hearth/sig/lib/hearth/configuration.rbs
index 6e537a36d..efb600d79 100644
--- a/hearth/sig/lib/hearth/configuration.rbs
+++ b/hearth/sig/lib/hearth/configuration.rbs
@@ -4,6 +4,9 @@ module Hearth
 
     attr_reader options: Hash[Symbol, untyped]
 
+    def to_h: (self) -> (Hash[Symbol, untyped] | self)
+    alias to_hash to_h
+
     def merge: (Hash[Symbol, untyped] configuration) -> ServiceConfig
   end
 end
diff --git a/hearth/sig/lib/hearth/dns/host_address.rbs b/hearth/sig/lib/hearth/dns/host_address.rbs
index 9d1987043..ed0b8847f 100644
--- a/hearth/sig/lib/hearth/dns/host_address.rbs
+++ b/hearth/sig/lib/hearth/dns/host_address.rbs
@@ -1,11 +1,13 @@
 module Hearth
   module DNS
-    class HostAddress < Struct[untyped]
-      attr_reader address_type: Symbol
+    class HostAddress
+      def initialize: (address_type: Symbol, address: String, hostname: String) -> void
 
-      attr_reader address: String
+      attr_accessor address_type: Symbol
 
-      attr_reader hostname: String
+      attr_accessor address: String
+
+      attr_accessor hostname: String
     end
   end
 end
diff --git a/hearth/sig/lib/hearth/endpoint_rules.rbs b/hearth/sig/lib/hearth/endpoint_rules.rbs
index 85cb1b9d9..ea634257a 100644
--- a/hearth/sig/lib/hearth/endpoint_rules.rbs
+++ b/hearth/sig/lib/hearth/endpoint_rules.rbs
@@ -1,12 +1,16 @@
 module Hearth
   module EndpointRules
-    class AuthScheme < Struct[untyped]
+    class AuthScheme
+      def initialize: (scheme_id: String, ?properties: ::Hash[String, untyped]) -> void
+
       attr_accessor scheme_id: String
 
       attr_accessor properties: Hash[String, untyped]
     end
 
-    class Endpoint < Struct[untyped]
+    class Endpoint
+      def initialize: (uri: String, ?auth_schemes: Array[AuthScheme], ?headers: Hash[String, String | Array[String]]) -> void
+
       attr_accessor uri: String
 
       attr_accessor auth_schemes: Array[AuthScheme]
diff --git a/hearth/sig/lib/hearth/retry.rbs b/hearth/sig/lib/hearth/retry.rbs
index 375b4422f..176fa41ff 100644
--- a/hearth/sig/lib/hearth/retry.rbs
+++ b/hearth/sig/lib/hearth/retry.rbs
@@ -1,6 +1,8 @@
 module Hearth
   module Retry
-    class Token < Struct[untyped]
+    class Token
+      def initialize: (?retry_count: Integer, ?retry_delay: Numeric) -> void
+
       attr_accessor retry_count (): Integer
 
       attr_accessor retry_delay (): Numeric
diff --git a/hearth/sig/lib/hearth/structure.rbs b/hearth/sig/lib/hearth/structure.rbs
index 67e76e0d5..3f2984385 100644
--- a/hearth/sig/lib/hearth/structure.rbs
+++ b/hearth/sig/lib/hearth/structure.rbs
@@ -1,6 +1,9 @@
 module Hearth
   module Structure
-    def to_h: (self) -> (Hash[Symbol, untyped] | self)
+    def to_h: (self) -> Hash[Symbol, untyped]
     alias to_hash to_h
+
+    def to_s: (self) -> String
+    alias to_string to_s
   end
 end
diff --git a/hearth/spec/hearth/cbor/cbor_spec.rb b/hearth/spec/hearth/cbor/cbor_spec.rb
index 14f104429..679dae760 100644
--- a/hearth/spec/hearth/cbor/cbor_spec.rb
+++ b/hearth/spec/hearth/cbor/cbor_spec.rb
@@ -22,7 +22,7 @@ def expected_value(expect)
           end
         when 'tag'
           value = expected_value(expect['tag']['value'])
-          CBOR::Tagged.new(expect['tag']['id'], value)
+          CBOR::Tagged.new(tag: expect['tag']['id'], value: value)
         when 'bool' then expect['bool']
         when 'null' then nil
         when 'undefined' then :undefined
@@ -34,16 +34,20 @@ def expected_value(expect)
       end
 
       def assert(actual, expected)
-        if expected.is_a?(Float) && expected.nan?
-          expect(actual.nan?).to be true
-        elsif expected.is_a?(Array)
+        case expected
+        when Array
           expected.each_with_index do |item, i|
             assert(actual[i], item)
           end
-        elsif expected.is_a?(Hash)
+        when Hash
           expected.each do |key, value|
             assert(actual[key], value)
           end
+        when Float
+          expect(actual.nan?).to be true if expected.nan?
+        when CBOR::Tagged
+          expect(actual.tag).to eq(expected.tag)
+          expect(actual.value).to eq(expected.value)
         else
           expect(actual).to eq(expected)
         end
diff --git a/hearth/spec/hearth/cbor/encoder_spec.rb b/hearth/spec/hearth/cbor/encoder_spec.rb
index fde5141aa..2f9960848 100644
--- a/hearth/spec/hearth/cbor/encoder_spec.rb
+++ b/hearth/spec/hearth/cbor/encoder_spec.rb
@@ -59,7 +59,7 @@ def cbor64_encode(value)
         end
 
         it 'encodes Tagged items' do
-          expect(cbor64_encode(Tagged.new(0, 0))).to eq('wAA=')
+          expect(cbor64_encode(Tagged.new(tag: 0, value: 0))).to eq('wAA=')
         end
 
         it 'encodes arrays' do
diff --git a/hearth/spec/hearth/client_spec.rb b/hearth/spec/hearth/client_spec.rb
index 90c12327d..8ab004e4c 100644
--- a/hearth/spec/hearth/client_spec.rb
+++ b/hearth/spec/hearth/client_spec.rb
@@ -1,15 +1,23 @@
 # frozen_string_literal: true
 
 module Hearth
-  module Test
-    Config = Struct.new(
-      :stub_responses, :stubs, :plugins, :interceptors, keyword_init: true
-    ) do
+  module TestClient
+    class Config
+      MEMBERS = %i[
+        stub_responses
+        stubs
+        plugins
+        interceptors
+      ].freeze
+
       include Hearth::Configuration
+
+      attr_accessor(*MEMBERS)
+
       def validate!
         Hearth::Validator.validate_types!(
-          stub_responses, TrueClass,
-          FalseClass, context: 'config[:stub_responses]'
+          stub_responses, TrueClass, FalseClass,
+          context: 'config[:stub_responses]'
         )
         Hearth::Validator.validate_types!(
           stubs, Hearth::Stubs,
@@ -20,8 +28,8 @@ def validate!
           context: 'config[:plugins]'
         )
         Hearth::Validator.validate_types!(
-          interceptors,
-          Hearth::InterceptorList, context: 'config[:interceptors]'
+          interceptors, Hearth::InterceptorList,
+          context: 'config[:interceptors]'
         )
       end
 
@@ -53,7 +61,7 @@ def operation_body_stream(_params = {}, options = {}, &block)
   end
 
   describe Client do
-    let(:subject) { Test::Client.new(stub_responses: true) }
+    let(:subject) { TestClient::Client.new(stub_responses: true) }
     let(:plugin) { proc { |_cfg| } }
     let(:interceptor) do
       Class.new do
@@ -63,7 +71,7 @@ def read_before_signing(*args); end
 
     after(:each) do
       # cleanup any class plugins
-      Test::Client.instance_variable_set(:@plugins, nil)
+      TestClient::Client.instance_variable_set(:@plugins, nil)
     end
 
     describe '#initialize' do
@@ -73,23 +81,23 @@ def read_before_signing(*args); end
 
       it 'validates config' do
         expect do
-          Test::Client.new(stub_responses: 'not a boolean')
+          TestClient::Client.new(stub_responses: 'not a boolean')
         end.to raise_error(ArgumentError, /config\[:stub_responses\]/)
       end
 
       it 'calls each Class plugin' do
-        Test::Client.plugins << plugin
+        TestClient::Client.plugins << plugin
         expect(plugin).to receive(:call)
-        Test::Client.new
+        TestClient::Client.new
       end
 
       it 'calls each plugin from initialize' do
         expect(plugin).to receive(:call)
-        Test::Client.new(plugins: PluginList.new([plugin]))
+        TestClient::Client.new(plugins: PluginList.new([plugin]))
       end
 
       it 'appends interceptors' do
-        client = Test::Client.new(interceptors: [interceptor])
+        client = TestClient::Client.new(interceptors: [interceptor])
         expect(client.config.interceptors.to_a).to include(interceptor)
       end
 
@@ -100,7 +108,7 @@ def read_before_signing(*args); end
 
     describe '#inspect' do
       it 'is the class name without instance variables' do
-        expect(subject.inspect).to eq('#<Hearth::Test::Client>')
+        expect(subject.inspect).to eq('#<Hearth::TestClient::Client>')
       end
     end
 
@@ -118,11 +126,15 @@ def read_before_signing(*args); end
       end
 
       it 'returns a config object' do
-        expect(subject.operation).to be_a(Test::Config)
+        expect(subject.operation).to be_a(TestClient::Config)
       end
 
       it 'has the same values as the client config' do
-        expect(subject.operation).to eq(subject.config)
+        actual = subject.operation
+        expected = subject.config
+        actual.class::MEMBERS.each do |member|
+          expect(actual.send(member)).to eq(expected.send(member))
+        end
       end
 
       it 'calls operation plugins' do
diff --git a/hearth/spec/hearth/config/resolver_spec.rb b/hearth/spec/hearth/config/resolver_spec.rb
index e1702292c..ee2ce893e 100644
--- a/hearth/spec/hearth/config/resolver_spec.rb
+++ b/hearth/spec/hearth/config/resolver_spec.rb
@@ -2,23 +2,24 @@
 
 module Hearth
   module Config
+    class TestResolverConfig
+      MEMBERS = %i[
+        option1
+        option2
+      ].freeze
+
+      attr_accessor(*MEMBERS)
+    end
+
     describe Resolver do
       subject { Resolver }
 
-      let(:config_class) do
-        Struct.new(
-          :option1,
-          :option2,
-          keyword_init: true
-        )
-      end
-
       it 'cannot be initialized' do
         expect { subject.new }.to raise_error(NoMethodError)
       end
 
       describe '.resolve' do
-        let(:config) { config_class.new }
+        let(:config) { TestResolverConfig.new }
 
         it 'creates the config with provided options' do
           defaults = { option1: ['should not be used'] }
diff --git a/hearth/spec/hearth/configuration_spec.rb b/hearth/spec/hearth/configuration_spec.rb
index f4a39079d..4ec5ecea1 100644
--- a/hearth/spec/hearth/configuration_spec.rb
+++ b/hearth/spec/hearth/configuration_spec.rb
@@ -1,62 +1,92 @@
 # frozen_string_literal: true
 
 module Hearth
-  describe Configuration do
-    let(:config_class) do
-      Struct.new(:simple_option, keyword_init: true) do
-        include Hearth::Configuration
+  class TestConfiguration
+    MEMBERS = %i[
+      simple_option
+      complex_option
+    ].freeze
 
-        def validate!
-          Hearth::Validator.validate_types!(
-            simple_option, String, context: 'config[:simple_option]'
-          )
-        end
+    include Hearth::Configuration
 
-        private
+    attr_accessor(*MEMBERS)
 
-        def _defaults
-          { simple_option: ['default'] }
-        end
-      end
+    def validate!
+      Hearth::Validator.validate_types!(
+        simple_option, String,
+        context: 'config[:simple_option]'
+      )
+      Hearth::Validator.validate_types!(
+        complex_option, Object,
+        context: 'config[:complex_option]'
+      )
+    end
+
+    private
+
+    def _defaults
+      {
+        simple_option: ['default'],
+        complex_option: [Object.new]
+      }.freeze
     end
+  end
 
+  describe Configuration do
     describe '#initialize' do
       it 'uses the config resolver' do
         options = { simple_option: 'test' }
         expect(Hearth::Config::Resolver).to receive(:resolve)
           .with(
-            an_instance_of(config_class),
+            an_instance_of(TestConfiguration),
             options,
-            { simple_option: ['default'] }
+            {
+              simple_option: ['default'],
+              complex_option: [an_instance_of(Object)]
+            }
           ).and_call_original
 
-        config = config_class.new(**options)
+        config = TestConfiguration.new(**options)
         expect(config.simple_option).to eq('test')
       end
 
       it 'resolves correctly when not passed any options' do
         expect(Hearth::Config::Resolver).to receive(:resolve)
           .with(
-            an_instance_of(config_class),
+            an_instance_of(TestConfiguration),
             {},
-            { simple_option: ['default'] }
+            {
+              simple_option: ['default'],
+              complex_option: [an_instance_of(Object)]
+            }
           ).and_call_original
 
-        config = config_class.new
+        config = TestConfiguration.new
         expect(config.simple_option).to eq('default')
       end
 
       it 'raises on unknown options' do
         expect do
-          config_class.new(unknown_option: 'test')
-        end.to raise_error(ArgumentError, /unknown_option/)
+          TestConfiguration.new(unknown_option: 'test')
+        end.to raise_error(ArgumentError, /config\[:unknown_option\]/)
+      end
+    end
+
+    describe '#to_h' do
+      it 'returns the configuration as a hash' do
+        object = Object.new
+        config = TestConfiguration.new(
+          simple_option: 'test',
+          complex_option: object
+        )
+        expect(config.to_h).to eq(simple_option: 'test', complex_option: object)
       end
     end
 
     describe '#merge' do
       it 'merges the configuration' do
-        config = config_class.new(simple_option: 'test')
-        merged = config.merge(config_class.new(simple_option: 'test2'))
+        config = TestConfiguration.new(simple_option: 'test')
+        merged = config.merge(TestConfiguration.new(simple_option: 'test2'))
         expect(merged.simple_option).to eq('test2')
       end
     end
diff --git a/hearth/spec/hearth/context_spec.rb b/hearth/spec/hearth/context_spec.rb
index 8e61ab049..b3de52707 100644
--- a/hearth/spec/hearth/context_spec.rb
+++ b/hearth/spec/hearth/context_spec.rb
@@ -48,7 +48,13 @@ module Hearth
 
     describe '#auth' do
       it 'allows for auth to be set' do
-        resolved_auth = Hearth::Middleware::Auth::ResolvedAuth.new
+        resolved_auth = Hearth::Middleware::Auth::ResolvedAuth.new(
+          scheme_id: double,
+          signer: double,
+          signer_properties: double,
+          identity: double,
+          identity_properties: double
+        )
         subject.auth = resolved_auth
         expect(subject.auth).to eq(resolved_auth)
       end
diff --git a/hearth/spec/hearth/dns/host_address_spec.rb b/hearth/spec/hearth/dns/host_address_spec.rb
index e87f46852..44fed5caa 100644
--- a/hearth/spec/hearth/dns/host_address_spec.rb
+++ b/hearth/spec/hearth/dns/host_address_spec.rb
@@ -3,13 +3,35 @@
 module Hearth
   module DNS
     describe HostAddress do
-      it 'can be initialized' do
+      let(:address_type) { :A }
+      let(:address) { '123.123.123.123' }
+      let(:hostname) { 'example.com' }
+
+      subject do
         HostAddress.new(
-          address_type: :A,
-          address: '123.123.123.123',
-          hostname: 'example.com'
+          address_type: address_type,
+          address: address,
+          hostname: hostname
         )
       end
+
+      describe '#address_type' do
+        it 'returns the address type' do
+          expect(subject.address_type).to eq(address_type)
+        end
+      end
+
+      describe '#address' do
+        it 'returns the address' do
+          expect(subject.address).to eq(address)
+        end
+      end
+
+      describe '#hostname' do
+        it 'returns the hostname' do
+          expect(subject.hostname).to eq(hostname)
+        end
+      end
     end
   end
 end
diff --git a/hearth/spec/hearth/http/error_parser_spec.rb b/hearth/spec/hearth/http/error_parser_spec.rb
index 24633d52d..3902e3f47 100644
--- a/hearth/spec/hearth/http/error_parser_spec.rb
+++ b/hearth/spec/hearth/http/error_parser_spec.rb
@@ -22,13 +22,13 @@ class ApiClientError < ApiError; end
 
       class ApiServerError < ApiError; end
 
-      class TestModeledError < ApiClientError; end
+      class ModeledError < ApiClientError; end
     end
 
     describe ErrorParser do
       let(:error_module) { TestErrors }
       let(:success_status) { 200 }
-      let(:errors) { [TestErrors::TestModeledError] }
+      let(:errors) { [TestErrors::ModeledError] }
 
       let(:resp_status) { 200 }
       let(:fields) { Fields.new }
@@ -98,7 +98,7 @@ class TestModeledError < ApiClientError; end
         context 'error code on response' do
           before do
             expect(TestErrors).to receive(:error_code)
-              .with(http_resp).and_return('TestModeledError')
+              .with(http_resp).and_return('ModeledError')
           end
 
           context 'error response: 2XX with error code' do
@@ -106,7 +106,7 @@ class TestModeledError < ApiClientError; end
 
             it 'returns the modeled error' do
               error = subject.parse(http_resp, metadata)
-              expect(error).to be_a(TestErrors::TestModeledError)
+              expect(error).to be_a(TestErrors::ModeledError)
             end
 
             context 'Modeled error not in errors' do
@@ -124,7 +124,7 @@ class TestModeledError < ApiClientError; end
 
             it 'returns the modeled error' do
               error = subject.parse(http_resp, metadata)
-              expect(error).to be_a(TestErrors::TestModeledError)
+              expect(error).to be_a(TestErrors::ModeledError)
             end
           end
         end
diff --git a/hearth/spec/hearth/middleware/endpoint_spec.rb b/hearth/spec/hearth/middleware/endpoint_spec.rb
index d99866d3e..e54dff1a6 100644
--- a/hearth/spec/hearth/middleware/endpoint_spec.rb
+++ b/hearth/spec/hearth/middleware/endpoint_spec.rb
@@ -2,10 +2,17 @@
 
 module Hearth
   module Middleware
+    class TestEndpointInput
+      include Hearth::Structure
+
+      MEMBERS = %i[foo].freeze
+
+      attr_accessor(*MEMBERS)
+    end
+
     describe Endpoint do
       let(:app) { double('app', call: output) }
-      let(:struct) { Struct.new(:foo, keyword_init: true) }
-      let(:input) { struct.new }
+      let(:input) { TestEndpointInput.new }
       let(:output) { double('output') }
       let(:endpoint_resolver) { double }
       let(:param_builder) { double }
diff --git a/hearth/spec/hearth/middleware/host_prefix_spec.rb b/hearth/spec/hearth/middleware/host_prefix_spec.rb
index 89f97a72a..0335c6369 100644
--- a/hearth/spec/hearth/middleware/host_prefix_spec.rb
+++ b/hearth/spec/hearth/middleware/host_prefix_spec.rb
@@ -2,10 +2,17 @@
 
 module Hearth
   module Middleware
+    class TestHostPrefixInput
+      include Hearth::Structure
+
+      MEMBERS = %i[foo].freeze
+
+      attr_accessor(*MEMBERS)
+    end
+
     describe HostPrefix do
       let(:app) { double('app', call: output) }
-      let(:struct) { Struct.new(:foo, keyword_init: true) }
-      let(:input) { struct.new }
+      let(:input) { TestHostPrefixInput.new }
       let(:output) { double('output') }
       let(:host_prefix) { 'foo.' }
 
@@ -42,7 +49,7 @@ module Middleware
 
           context 'host prefix has labels' do
             let(:host_prefix) { '{foo}.' }
-            let(:input) { struct.new(foo: 'bar') }
+            let(:input) { TestHostPrefixInput.new(foo: 'bar') }
 
             it 'populates the label with input' do
               expect(app).to receive(:call).with(input, context)
@@ -53,7 +60,7 @@ module Middleware
             end
 
             context 'input does not have the label' do
-              let(:input) { struct.new }
+              let(:input) { TestHostPrefixInput.new }
 
               it 'raises an ArgumentError' do
                 expect do
@@ -63,7 +70,7 @@ module Middleware
             end
 
             context 'input has an empty label' do
-              let(:input) { struct.new(foo: '') }
+              let(:input) { TestHostPrefixInput.new(foo: '') }
 
               it 'raises an ArgumentError' do
                 expect do
diff --git a/hearth/spec/hearth/middleware/send_spec.rb b/hearth/spec/hearth/middleware/send_spec.rb
index 995bb918f..cc07f1305 100644
--- a/hearth/spec/hearth/middleware/send_spec.rb
+++ b/hearth/spec/hearth/middleware/send_spec.rb
@@ -2,34 +2,44 @@
 
 module Hearth
   module Middleware
-    module Types
-      StubData = ::Struct.new(:member, keyword_init: true) do
-        include Hearth::Structure
-      end
+    module TestStubs
+      module Types
+        class StubData
+          include Hearth::Structure
 
-      StubErrorData = ::Struct.new(:message, keyword_init: true) do
-        include Hearth::Structure
-      end
-    end
+          MEMBERS = %i[member].freeze
 
-    module Errors
-      class StubError < StandardError; end
-      class OtherError < StandardError; end
-    end
+          attr_accessor(*MEMBERS)
+        end
+
+        class StubErrorData
+          include Hearth::Structure
+
+          MEMBERS = %i[message].freeze
 
-    module Stubs
-      class StubData
-        def self.build(params, context:); end
-        def self.validate!(output, context:); end
-        def self.default(visited = []); end
-        def self.stub(resp, stub:); end
+          attr_accessor(*MEMBERS)
+        end
       end
 
-      class StubError
-        def self.build(params, context:); end
-        def self.validate!(output, context:); end
-        def self.default(visited = []); end
-        def self.stub(resp, stub:); end
+      module Errors
+        class StubError < StandardError; end
+        class OtherError < StandardError; end
+      end
+
+      module Stubs
+        class StubData
+          def self.build(params, context:); end
+          def self.validate!(output, context:); end
+          def self.default(visited = []); end
+          def self.stub(resp, stub:); end
+        end
+
+        class StubError
+          def self.build(params, context:); end
+          def self.validate!(output, context:); end
+          def self.default(visited = []); end
+          def self.stub(resp, stub:); end
+        end
       end
     end
 
@@ -46,8 +56,8 @@ def self.stub(resp, stub:); end
           app,
           client: client,
           stub_responses: stub_responses,
-          stub_data_class: Stubs::StubData,
-          stub_error_classes: [Stubs::StubError],
+          stub_data_class: TestStubs::Stubs::StubData,
+          stub_error_classes: [TestStubs::Stubs::StubError],
           stubs: stubs
         )
       end
@@ -241,17 +251,17 @@ def self.stub(resp, stub:); end
           context 'stub is a hash' do
             context 'data stub' do
               let(:stub_hash) { { member: 'value' } }
-              let(:stub_data) { Types::StubData.new(**stub_hash) }
+              let(:stub_data) { TestStubs::Types::StubData.new(**stub_hash) }
 
               before { stubs.set_stubs(operation, [{ data: stub_hash }]) }
 
               it 'uses the data hash to stub the response' do
-                expect(Stubs::StubData).to receive(:build)
+                expect(TestStubs::Stubs::StubData).to receive(:build)
                   .with(stub_hash, context: 'stub')
                   .and_return(stub_data)
-                expect(Stubs::StubData).to receive(:validate!)
+                expect(TestStubs::Stubs::StubData).to receive(:validate!)
                   .with(stub_data, context: 'stub')
-                expect(Stubs::StubData).to receive(:stub)
+                expect(TestStubs::Stubs::StubData).to receive(:stub)
                   .with(response, stub: stub_data)
                 subject.call(input, context)
               end
@@ -262,12 +272,12 @@ def self.stub(resp, stub:); end
                 before { stubs.set_stubs(operation, [stub_proc]) }
 
                 it 'uses the data hash to stub the response' do
-                  expect(Stubs::StubData).to receive(:build)
+                  expect(TestStubs::Stubs::StubData).to receive(:build)
                     .with(stub_hash, context: 'stub')
                     .and_return(stub_data)
-                  expect(Stubs::StubData).to receive(:validate!)
+                  expect(TestStubs::Stubs::StubData).to receive(:validate!)
                     .with(stub_data, context: 'stub')
-                  expect(Stubs::StubData).to receive(:stub)
+                  expect(TestStubs::Stubs::StubData).to receive(:stub)
                     .with(response, stub: stub_data)
                   subject.call(input, context)
                 end
@@ -276,20 +286,22 @@ def self.stub(resp, stub:); end
 
             context 'error stub' do
               let(:stub_hash) do
-                { class: Errors::StubError, data: stub_error_data }
+                { class: TestStubs::Errors::StubError, data: stub_error_data }
               end
               let(:stub_error_data) { { message: 'error' } }
-              let(:stub_error) { Types::StubErrorData.new(**stub_error_data) }
+              let(:stub_error) do
+                TestStubs::Types::StubErrorData.new(**stub_error_data)
+              end
 
               before { stubs.set_stubs(operation, [{ error: stub_hash }]) }
 
               it 'uses the error hash to stub the response' do
-                expect(Stubs::StubError).to receive(:build)
+                expect(TestStubs::Stubs::StubError).to receive(:build)
                   .with(stub_error_data, context: 'stub')
                   .and_return(stub_error)
-                expect(Stubs::StubError).to receive(:validate!)
+                expect(TestStubs::Stubs::StubError).to receive(:validate!)
                   .with(stub_error, context: 'stub')
-                expect(Stubs::StubError).to receive(:stub)
+                expect(TestStubs::Stubs::StubError).to receive(:stub)
                   .with(response, stub: stub_error)
                 subject.call(input, context)
               end
@@ -300,12 +312,12 @@ def self.stub(resp, stub:); end
                 before { stubs.set_stubs(operation, [stub_proc]) }
 
                 it 'uses the error hash to stub the response' do
-                  expect(Stubs::StubError).to receive(:build)
+                  expect(TestStubs::Stubs::StubError).to receive(:build)
                     .with(stub_error_data, context: 'stub')
                     .and_return(stub_error)
-                  expect(Stubs::StubError).to receive(:validate!)
+                  expect(TestStubs::Stubs::StubError).to receive(:validate!)
                     .with(stub_error, context: 'stub')
-                  expect(Stubs::StubError).to receive(:stub)
+                  expect(TestStubs::Stubs::StubError).to receive(:stub)
                     .with(response, stub: stub_error)
                   subject.call(input, context)
                 end
@@ -332,7 +344,7 @@ def self.stub(resp, stub:); end
               end
 
               it 'raises with unknown error class' do
-                stub_hash[:class] = Errors::OtherError
+                stub_hash[:class] = TestStubs::Errors::OtherError
                 expect do
                   subject.call(input, context)
                 end.to raise_error(
@@ -363,18 +375,18 @@ def self.stub(resp, stub:); end
 
           context 'stub is nil' do
             let(:stub_hash) { { member: 'value' } }
-            let(:stub_data) { Types::StubData.new(**stub_hash) }
+            let(:stub_data) { TestStubs::Types::StubData.new(**stub_hash) }
 
             before { stubs.set_stubs(operation, [nil]) }
 
             it 'uses the stub class default' do
-              expect(Stubs::StubData).to receive(:default)
+              expect(TestStubs::Stubs::StubData).to receive(:default)
                 .and_return(stub_hash)
-              expect(Stubs::StubData).to receive(:build)
+              expect(TestStubs::Stubs::StubData).to receive(:build)
                 .with(stub_hash, context: 'stub')
                 .and_return(stub_data)
-              expect(Stubs::StubData).to receive(:validate!)
-              expect(Stubs::StubData).to receive(:stub)
+              expect(TestStubs::Stubs::StubData).to receive(:validate!)
+              expect(TestStubs::Stubs::StubData).to receive(:stub)
                 .with(response, stub: stub_data)
               subject.call(input, context)
             end
@@ -385,13 +397,13 @@ def self.stub(resp, stub:); end
               before { stubs.set_stubs(operation, [stub_proc]) }
 
               it 'uses the stub class default' do
-                expect(Stubs::StubData).to receive(:default)
+                expect(TestStubs::Stubs::StubData).to receive(:default)
                   .and_return(stub_hash)
-                expect(Stubs::StubData).to receive(:build)
+                expect(TestStubs::Stubs::StubData).to receive(:build)
                   .with(stub_hash, context: 'stub')
                   .and_return(stub_data)
-                expect(Stubs::StubData).to receive(:validate!)
-                expect(Stubs::StubData).to receive(:stub)
+                expect(TestStubs::Stubs::StubData).to receive(:validate!)
+                expect(TestStubs::Stubs::StubData).to receive(:stub)
                   .with(response, stub: stub_data)
                 subject.call(input, context)
               end
@@ -399,14 +411,14 @@ def self.stub(resp, stub:); end
           end
 
           context 'stub is a Hearth::Structure' do
-            let(:stub_data) { Types::StubData.new(member: 'value') }
+            let(:stub_data) { TestStubs::Types::StubData.new(member: 'value') }
 
             before { stubs.set_stubs(operation, [stub_data]) }
 
             it 'uses the stub class to stub the response' do
-              expect(Stubs::StubData).to receive(:validate!)
+              expect(TestStubs::Stubs::StubData).to receive(:validate!)
                 .with(stub_data, context: 'stub')
-              expect(Stubs::StubData).to receive(:stub)
+              expect(TestStubs::Stubs::StubData).to receive(:stub)
                 .with(response, stub: stub_data)
               subject.call(input, context)
             end
@@ -417,9 +429,9 @@ def self.stub(resp, stub:); end
               before { stubs.set_stubs(operation, [stub_proc]) }
 
               it 'uses the stub class to stub the response' do
-                expect(Stubs::StubData).to receive(:validate!)
+                expect(TestStubs::Stubs::StubData).to receive(:validate!)
                   .with(stub_data, context: 'stub')
-                expect(Stubs::StubData).to receive(:stub)
+                expect(TestStubs::Stubs::StubData).to receive(:stub)
                   .with(response, stub: stub_data)
                 subject.call(input, context)
               end
diff --git a/hearth/spec/hearth/structure_spec.rb b/hearth/spec/hearth/structure_spec.rb
index f835de22b..e1a70e944 100644
--- a/hearth/spec/hearth/structure_spec.rb
+++ b/hearth/spec/hearth/structure_spec.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 module Hearth
-  class MyStructure
+  class TestStructure
     include Hearth::Structure
 
     MEMBERS = %i[
@@ -27,15 +27,15 @@ def _defaults
 
   describe Structure do
     subject do
-      MyStructure.new(
-        struct_value: MyStructure.new(value: 'foo'),
+      TestStructure.new(
+        struct_value: TestStructure.new(value: 'foo'),
         array_value: [
-          MyStructure.new(value: 'foo'),
-          MyStructure.new(value: 'bar')
+          TestStructure.new(value: 'foo'),
+          TestStructure.new(value: 'bar')
         ],
-        hash_value: { key: MyStructure.new(value: 'value') },
+        hash_value: { key: TestStructure.new(value: 'value') },
         value: 'value',
-        union_value: MyUnion::StringValue.new('union'),
+        union_value: TestUnion::StringValue.new('union'),
         some_object: Object.new
       )
     end
@@ -46,7 +46,7 @@ def _defaults
       end
     end
 
-    describe '#to_hash' do
+    describe '#to_h' do
       it 'serializes nested structs to a hash' do
         expected = {
           struct_value: { value: 'foo', default_value: 'default' },
@@ -65,5 +65,20 @@ def _defaults
         expect(subject.to_h).to eq expected
       end
     end
+
+    describe '#to_s' do
+      it 'returns a string representation of the structure' do
+        actual = subject.to_s
+        expect(actual).to include(subject.class.name)
+        expect(actual).to include(subject.struct_value.to_s)
+        expect(actual).to include(subject.array_value.first.to_s)
+        expect(actual).to include(subject.array_value.last.to_s)
+        expect(actual).to include(subject.hash_value[:key].to_s)
+        expect(actual).to include(subject.value)
+        expect(actual).to include(subject.union_value.to_s)
+        expect(actual).to include(subject.some_object.to_s)
+        expect(actual).to include(subject.default_value)
+      end
+    end
   end
 end
diff --git a/hearth/spec/hearth/stubbing/client_stubs_spec.rb b/hearth/spec/hearth/stubbing/client_stubs_spec.rb
index 0a2a1eae6..fb7a1489f 100644
--- a/hearth/spec/hearth/stubbing/client_stubs_spec.rb
+++ b/hearth/spec/hearth/stubbing/client_stubs_spec.rb
@@ -1,15 +1,31 @@
 # frozen_string_literal: true
 
 module Hearth
-  module ClientStubTest
-    Config = Struct.new(:stub_responses, :stubs, keyword_init: true)
+  module TestClientStubs
+    class Config
+      MEMBERS = %i[
+        stub_responses
+        stubs
+      ].freeze
+
+      include Hearth::Configuration
+
+      attr_accessor(*MEMBERS)
+
+      private
+
+      def _defaults
+        {
+          stubs: [Hearth::Stubs.new]
+        }.freeze
+      end
+    end
 
     class Client
       include ClientStubs
 
       def initialize(config = Config.new)
         @config = config
-        @config.stubs = Hearth::Stubs.new
       end
 
       attr_accessor :config
@@ -17,8 +33,11 @@ def initialize(config = Config.new)
   end
 
   describe ClientStubs do
-    let(:config) { ClientStubTest::Config.new(stub_responses: stub_responses) }
-    subject { ClientStubTest::Client.new(config) }
+    let(:config) do
+      TestClientStubs::Config.new(stub_responses: stub_responses)
+    end
+
+    subject { TestClientStubs::Client.new(config) }
 
     describe '#stub_responses' do
       context 'stub_responses is true' do
diff --git a/hearth/spec/hearth/union_spec.rb b/hearth/spec/hearth/union_spec.rb
index 58875f651..5146fa66c 100644
--- a/hearth/spec/hearth/union_spec.rb
+++ b/hearth/spec/hearth/union_spec.rb
@@ -1,8 +1,8 @@
 # frozen_string_literal: true
 
 module Hearth
-  class MyUnion < Hearth::Union
-    class StringValue < MyUnion
+  class TestUnion < Hearth::Union
+    class StringValue < TestUnion
       def to_h
         { string_value: super(__getobj__) }
       end
@@ -10,7 +10,7 @@ def to_h
   end
 
   describe Union do
-    subject { MyUnion::StringValue.new('union') }
+    subject { TestUnion::StringValue.new('union') }
 
     it 'uses simple delegator and structure' do
       expect(subject).to be_a(SimpleDelegator)
@@ -22,5 +22,12 @@ def to_h
         expect(subject.to_h).to eq(string_value: 'union')
       end
     end
+
+    describe '#to_s' do
+      it 'returns a string representation' do
+        expect(subject.to_s)
+          .to eq('#<Hearth::TestUnion::StringValue union>')
+      end
+    end
   end
 end
diff --git a/hearth/spec/hearth/validator_spec.rb b/hearth/spec/hearth/validator_spec.rb
index b944794a4..ef18bd228 100644
--- a/hearth/spec/hearth/validator_spec.rb
+++ b/hearth/spec/hearth/validator_spec.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 module Hearth
-  class MyType
+  class TestValidatorInput
     include Hearth::Structure
 
     MEMBERS = %i[foo].freeze
@@ -10,7 +10,7 @@ class MyType
   end
 
   describe Validator do
-    let(:input) { MyType.new(params) }
+    let(:input) { TestValidatorInput.new(params) }
     let(:context) { 'input' }
 
     describe '.validate_range!' do
@@ -180,7 +180,7 @@ class MyType
     end
 
     describe '.validate_unknown!' do
-      let(:input) { MyType.new }
+      let(:input) { TestValidatorInput.new }
 
       context 'all members are known' do
         let(:params) { { foo: 'bar' } }
diff --git a/hearth/spec/hearth/waiters/poller_spec.rb b/hearth/spec/hearth/waiters/poller_spec.rb
index 57ae5bcb3..0acba65c9 100644
--- a/hearth/spec/hearth/waiters/poller_spec.rb
+++ b/hearth/spec/hearth/waiters/poller_spec.rb
@@ -2,6 +2,14 @@
 
 module Hearth
   module Waiters
+    class TestWaiterInput
+      include Hearth::Structure
+
+      MEMBERS = %i[string boolean all_string any_string].freeze
+
+      attr_accessor(*MEMBERS)
+    end
+
     describe Poller do
       subject do
         Poller.new(
@@ -12,18 +20,8 @@ module Waiters
 
       let(:client) { double('client') }
       let(:input_output_interceptor) { double('input_output_interceptor') }
-
-      let(:test_operation_struct) do
-        Struct.new(
-          :string,
-          :boolean,
-          :all_string,
-          :any_string,
-          keyword_init: true
-        )
-      end
-      let(:struct) do
-        test_operation_struct.new(
+      let(:input) do
+        TestWaiterInput.new(
           string: 'peccy',
           boolean: true,
           all_string: %w[foo foo],
@@ -32,7 +30,7 @@ module Waiters
       end
 
       let(:interceptor_context) do
-        double('ictx', input: struct)
+        double('ictx', input: input)
       end
 
       let(:error) do
@@ -73,9 +71,9 @@ module Waiters
             it 'returns retry state with response' do
               expect(client).to receive(:test_operation)
                 .with({}, { interceptors: [input_output_interceptor] })
-                .and_return(struct)
+                .and_return(input)
 
-              expect(subject.call(client, {}, {})).to eq [:retry, struct]
+              expect(subject.call(client, {}, {})).to eq [:retry, input]
             end
           end
         end
@@ -90,9 +88,9 @@ module Waiters
           it 'can match success' do
             expect(client).to receive(:test_operation)
               .with({}, { interceptors: [input_output_interceptor] })
-              .and_return(struct)
+              .and_return(input)
 
-            expect(subject.call(client, {}, {})).to eq [:success, struct]
+            expect(subject.call(client, {}, {})).to eq [:success, input]
           end
         end
 
@@ -132,9 +130,9 @@ module Waiters
             it 'can match string equals' do
               expect(client).to receive(:test_operation)
                 .with({}, { interceptors: [input_output_interceptor] })
-                .and_return(struct)
+                .and_return(input)
 
-              expect(subject.call(client, {}, {})).to eq [:success, struct]
+              expect(subject.call(client, {}, {})).to eq [:success, input]
             end
           end
 
@@ -157,9 +155,9 @@ module Waiters
             it 'can match boolean equals' do
               expect(client).to receive(:test_operation)
                 .with({}, { interceptors: [input_output_interceptor] })
-                .and_return(struct)
+                .and_return(input)
 
-              expect(subject.call(client, {}, {})).to eq [:success, struct]
+              expect(subject.call(client, {}, {})).to eq [:success, input]
             end
           end
 
@@ -182,9 +180,9 @@ module Waiters
             it 'can match boolean equals' do
               expect(client).to receive(:test_operation)
                 .with({}, { interceptors: [input_output_interceptor] })
-                .and_return(struct)
+                .and_return(input)
 
-              expect(subject.call(client, {}, {})).to eq [:success, struct]
+              expect(subject.call(client, {}, {})).to eq [:success, input]
             end
           end
 
@@ -207,9 +205,9 @@ module Waiters
             it 'can match boolean equals' do
               expect(client).to receive(:test_operation)
                 .with({}, { interceptors: [input_output_interceptor] })
-                .and_return(struct)
+                .and_return(input)
 
-              expect(subject.call(client, {}, {})).to eq [:success, struct]
+              expect(subject.call(client, {}, {})).to eq [:success, input]
             end
           end
         end
@@ -234,9 +232,9 @@ module Waiters
             it 'can match string equals' do
               expect(client).to receive(:test_operation)
                 .with({}, { interceptors: [input_output_interceptor] })
-                .and_return(struct)
+                .and_return(input)
 
-              expect(subject.call(client, {}, {})).to eq [:success, struct]
+              expect(subject.call(client, {}, {})).to eq [:success, input]
             end
           end
 
@@ -259,9 +257,9 @@ module Waiters
             it 'can match boolean equals' do
               expect(client).to receive(:test_operation)
                 .with({}, { interceptors: [input_output_interceptor] })
-                .and_return(struct)
+                .and_return(input)
 
-              expect(subject.call(client, {}, {})).to eq [:success, struct]
+              expect(subject.call(client, {}, {})).to eq [:success, input]
             end
           end
 
@@ -284,9 +282,9 @@ module Waiters
             it 'can match boolean equals' do
               expect(client).to receive(:test_operation)
                 .with({}, { interceptors: [input_output_interceptor] })
-                .and_return(struct)
+                .and_return(input)
 
-              expect(subject.call(client, {}, {})).to eq [:success, struct]
+              expect(subject.call(client, {}, {})).to eq [:success, input]
             end
           end
 
@@ -309,9 +307,9 @@ module Waiters
             it 'can match boolean equals' do
               expect(client).to receive(:test_operation)
                 .with({}, { interceptors: [input_output_interceptor] })
-                .and_return(struct)
+                .and_return(input)
 
-              expect(subject.call(client, {}, {})).to eq [:success, struct]
+              expect(subject.call(client, {}, {})).to eq [:success, input]
             end
           end
         end
@@ -345,9 +343,9 @@ module Waiters
           it 'iterates all matchers' do
             expect(client).to receive(:test_operation)
               .with({}, { interceptors: [input_output_interceptor] })
-              .and_return(struct)
+              .and_return(input)
 
-            expect(subject.call(client, {}, {})).to eq [:success, struct]
+            expect(subject.call(client, {}, {})).to eq [:success, input]
           end
         end
       end
diff --git a/hearth/spec/hearth/waiters/waiter_spec.rb b/hearth/spec/hearth/waiters/waiter_spec.rb
index aaf9f83fb..4ef1330ce 100644
--- a/hearth/spec/hearth/waiters/waiter_spec.rb
+++ b/hearth/spec/hearth/waiters/waiter_spec.rb
@@ -26,6 +26,14 @@ module Waiters
       end
     end
 
+    class TestWaiterOutput
+      include Hearth::Structure
+
+      MEMBERS = %i[member].freeze
+
+      attr_accessor(*MEMBERS)
+    end
+
     describe Waiter do
       subject do
         Waiter.new(
@@ -38,9 +46,7 @@ module Waiters
 
       let(:poller) { double('poller') }
       let(:client) { double('client') }
-
-      let(:response_struct) { Struct.new(:member, keyword_init: true) }
-      let(:response) { response_struct.new(member: 'foo') }
+      let(:response) { TestWaiterOutput.new(member: 'foo') }
 
       let(:error) do
         Hearth::ApiError.new(