From 379b055cc7132d93e8e749fad8b05ff644f8b924 Mon Sep 17 00:00:00 2001
From: Juli Tera <terajul@amazon.com>
Date: Wed, 3 Jun 2026 15:02:30 -0700
Subject: [PATCH 01/23] Change ShapeRef to MemberShape

---
 gems/smithy-cbor/lib/smithy-cbor/builder.rb   | 18 ++---
 gems/smithy-cbor/lib/smithy-cbor/codec.rb     |  4 +-
 gems/smithy-cbor/lib/smithy-cbor/parser.rb    | 22 +++---
 gems/smithy-cbor/sig/smithy-cbor/codec.rbs    |  4 +-
 .../spec/smithy-cbor/builder_spec.rb          |  4 +-
 .../lib/smithy-client/default_params.rb       | 10 +--
 .../lib/smithy-client/log_param_filter.rb     | 18 ++---
 .../lib/smithy-client/param_converter.rb      | 16 ++---
 .../lib/smithy-client/param_validator.rb      | 26 +++----
 .../lib/smithy-client/plugins/host_prefix.rb  |  2 +-
 .../plugins/idempotency_token.rb              |  2 +-
 .../plugins/request_compression.rb            |  6 +-
 .../plugins/transfer_encoding.rb              |  6 +-
 .../rpc_v2_cbor/error_handler.rb              |  4 +-
 .../lib/smithy-client/rpc_v2_cbor/handler.rb  |  6 +-
 .../smithy-client/stubbing/data_applicator.rb | 10 +--
 .../lib/smithy-client/stubbing/empty_stub.rb  |  8 +--
 .../smithy-client/log_param_filter_spec.rb    |  4 +-
 .../smithy-client/param_converter_spec.rb     |  4 +-
 .../plugins/transfer_encoding_spec.rb         |  4 +-
 gems/smithy-json/lib/smithy-json/builder.rb   | 18 ++---
 gems/smithy-json/lib/smithy-json/codec.rb     |  4 +-
 gems/smithy-json/lib/smithy-json/parser.rb    | 22 +++---
 gems/smithy-json/sig/smithy-json/codec.rbs    |  4 +-
 .../spec/smithy-json/builder_spec.rb          |  4 +-
 .../document_utils/deserializer.rb            | 20 +++---
 .../document_utils/serializer.rb              | 18 ++---
 .../smithy-schema/lib/smithy-schema/shapes.rb | 46 ++++++-------
 .../sig/smithy-schema/shapes.rbs              | 44 ++++++------
 .../spec/smithy-schema/shapes_spec.rb         | 68 +++++++++----------
 gems/smithy-xml/lib/smithy-xml/builder.rb     | 30 ++++----
 gems/smithy-xml/lib/smithy-xml/codec.rb       |  4 +-
 gems/smithy-xml/lib/smithy-xml/parser.rb      |  4 +-
 .../smithy-xml/lib/smithy-xml/parser/frame.rb | 22 +++---
 gems/smithy-xml/sig/smithy-xml/codec.rbs      |  4 +-
 .../spec/smithy-xml/builder_spec.rb           |  6 +-
 .../smithy/templates/client/errors_rbs.erb    |  2 +-
 .../lib/smithy/templates/client/schema.erb    |  2 +-
 gems/smithy/lib/smithy/views/client/schema.rb | 28 ++++----
 .../spec/interfaces/rename_shapes_spec.rb     |  4 +-
 .../interfaces/synthetic_input_output_spec.rb | 12 ++--
 .../spec/support/examples/schema_examples.rb  | 24 +++----
 42 files changed, 284 insertions(+), 284 deletions(-)

diff --git a/gems/smithy-cbor/lib/smithy-cbor/builder.rb b/gems/smithy-cbor/lib/smithy-cbor/builder.rb
index 076e718dd..7eb4bab2b 100644
--- a/gems/smithy-cbor/lib/smithy-cbor/builder.rb
+++ b/gems/smithy-cbor/lib/smithy-cbor/builder.rb
@@ -13,8 +13,8 @@ def initialize(options = {})
       end
 
       def build(shape, data)
-        ref = shape.is_a?(ShapeRef) ? shape : ShapeRef.new(shape: shape)
-        return if ref.shape == Prelude::Unit
+        ref = shape.is_a?(MemberShape) ? shape : MemberShape.new(target: shape)
+        return if ref.target == Prelude::Unit
 
         Cbor.encode(shape(ref, data))
       end
@@ -22,7 +22,7 @@ def build(shape, data)
       private
 
       def shape(ref, value)
-        case ref.shape
+        case ref.target
         when BlobShape then blob(value)
         when ListShape then list(ref, value)
         when MapShape then map(ref, value)
@@ -39,7 +39,7 @@ def blob(value)
       def list(ref, values)
         return if values.nil?
 
-        shape = ref.shape
+        shape = ref.target
         values.collect do |value|
           shape(shape.member, value)
         end
@@ -48,7 +48,7 @@ def list(ref, values)
       def map(ref, values)
         return if values.nil?
 
-        shape = ref.shape
+        shape = ref.target
         values.each.with_object({}) do |(key, value), data|
           data[key] = shape(shape.value, value)
         end
@@ -57,7 +57,7 @@ def map(ref, values)
       def structure(ref, values)
         return if values.nil?
 
-        ref.shape.members.each_with_object({}) do |(member_name, member_ref), data|
+        ref.target.members.each_with_object({}) do |(member_name, member_ref), data|
           value = values[member_name]
           next if value.nil?
 
@@ -70,12 +70,12 @@ def union(ref, values) # rubocop:disable Metrics/AbcSize
 
         data = {}
         if values.is_a?(Schema::Union)
-          _name, member_ref = ref.shape.member_by_type(values.class)
+          _name, member_ref = ref.target.member_by_type(values.class)
           data[member_ref.location_name] = shape(member_ref, values.value)
         else
           key, value = values.first
-          if ref.shape.member?(key)
-            member_ref = ref.shape.member(key)
+          if ref.target.member?(key)
+            member_ref = ref.target.member(key)
             data[member_ref.location_name] = shape(member_ref, value)
           end
         end
diff --git a/gems/smithy-cbor/lib/smithy-cbor/codec.rb b/gems/smithy-cbor/lib/smithy-cbor/codec.rb
index 72e5cb451..1931e6c64 100644
--- a/gems/smithy-cbor/lib/smithy-cbor/codec.rb
+++ b/gems/smithy-cbor/lib/smithy-cbor/codec.rb
@@ -9,14 +9,14 @@ def initialize(options = {})
         @options = options
       end
 
-      # @param [ShapeRef, Shape] shape
+      # @param [MemberShape, Shape] shape
       # @param [Object] data
       # @return [String, nil]
       def build(shape, data)
         Builder.new(@options).build(shape, data)
       end
 
-      # @param [ShapeRef, Shape] shape
+      # @param [MemberShape, Shape] shape
       # @param [String] bytes
       # @param [Object, nil] target (nil)
       # @return [Object, nil]
diff --git a/gems/smithy-cbor/lib/smithy-cbor/parser.rb b/gems/smithy-cbor/lib/smithy-cbor/parser.rb
index 18b1fcb96..2d580df76 100644
--- a/gems/smithy-cbor/lib/smithy-cbor/parser.rb
+++ b/gems/smithy-cbor/lib/smithy-cbor/parser.rb
@@ -15,7 +15,7 @@ def initialize(options = {})
       def parse(shape, bytes, target = nil)
         return {} if bytes.empty?
 
-        ref = shape.is_a?(ShapeRef) ? shape : ShapeRef.new(shape: shape)
+        ref = shape.is_a?(MemberShape) ? shape : MemberShape.new(target: shape)
         shape(ref, Cbor.decode(bytes), target)
       end
 
@@ -24,7 +24,7 @@ def parse(shape, bytes, target = nil)
       def shape(ref, value, target = nil)
         return nil if value.nil?
 
-        case ref.shape
+        case ref.target
         when ListShape then list(ref, value, target)
         when MapShape then map(ref, value, target)
         when StructureShape then structure(ref, value, target)
@@ -36,9 +36,9 @@ def shape(ref, value, target = nil)
       def list(ref, values, target = nil)
         target = [] if target.nil?
         values.each do |value|
-          next if value.nil? && !sparse?(ref.shape)
+          next if value.nil? && !sparse?(ref.target)
 
-          target << shape(ref.shape.member, value)
+          target << shape(ref.target.member, value)
         end
         target
       end
@@ -46,16 +46,16 @@ def list(ref, values, target = nil)
       def map(ref, values, target = nil)
         target = {} if target.nil?
         values.each do |key, value|
-          next if value.nil? && !sparse?(ref.shape)
+          next if value.nil? && !sparse?(ref.target)
 
-          target[key] = shape(ref.shape.value, value)
+          target[key] = shape(ref.target.value, value)
         end
         target
       end
 
       def structure(ref, values, target = nil)
-        target = ref.shape.type.new if target.nil?
-        ref.shape.members.each do |member_name, member_ref|
+        target = ref.target.type.new if target.nil?
+        ref.target.members.each do |member_name, member_ref|
           value = values[member_ref.location_name]
           target[member_name] = shape(member_ref, value) unless value.nil?
         end
@@ -63,17 +63,17 @@ def structure(ref, values, target = nil)
       end
 
       def union(ref, values, target = nil) # rubocop:disable Metrics/AbcSize
-        ref.shape.members.each do |member_name, member_ref|
+        ref.target.members.each do |member_name, member_ref|
           value = values[member_ref.location_name]
           next if value.nil?
 
-          target = ref.shape.member_type(member_name) if target.nil?
+          target = ref.target.member_type(member_name) if target.nil?
           return target.new(member_name => shape(member_ref, value))
         end
 
         values.delete('__type')
         key, value = values.first
-        ref.shape.member_type(:unknown).new(unknown: { key => value })
+        ref.target.member_type(:unknown).new(unknown: { key => value })
       end
 
       def sparse?(shape)
diff --git a/gems/smithy-cbor/sig/smithy-cbor/codec.rbs b/gems/smithy-cbor/sig/smithy-cbor/codec.rbs
index 6febd3a71..2b6341287 100644
--- a/gems/smithy-cbor/sig/smithy-cbor/codec.rbs
+++ b/gems/smithy-cbor/sig/smithy-cbor/codec.rbs
@@ -2,8 +2,8 @@ module Smithy
   module Cbor
     module Codec
       def initialize: (?Hash[Symbol, untyped] options) -> void
-      def build: (Schema::Shapes::Shape | Schema::Shapes::ShapeRef shape, Object data) -> (nil | String)
-      def parse: (Schema::Shapes::Shape | Schema::Shapes::ShapeRef shape, String bytes, ?Object ?target) -> Object?
+      def build: (Schema::Shapes::Shape | Schema::Shapes::MemberShape shape, Object data) -> (nil | String)
+      def parse: (Schema::Shapes::Shape | Schema::Shapes::MemberShape shape, String bytes, ?Object ?target) -> Object?
     end
   end
 end
\ No newline at end of file
diff --git a/gems/smithy-cbor/spec/smithy-cbor/builder_spec.rb b/gems/smithy-cbor/spec/smithy-cbor/builder_spec.rb
index 72f363b0f..4ebead47d 100644
--- a/gems/smithy-cbor/spec/smithy-cbor/builder_spec.rb
+++ b/gems/smithy-cbor/spec/smithy-cbor/builder_spec.rb
@@ -77,7 +77,7 @@ module Cbor
 
       context 'unions' do
         it 'builds unions as a type' do
-          union = structure_shape.member(:union).shape.member_type(:string).new(string: 'string')
+          union = structure_shape.member(:union).target.member_type(:string).new(string: 'string')
           type = structure_shape.type.new(union: union)
           bytes = subject.build(structure_shape, type)
           expect(Cbor.decode(bytes)).to eq({ 'union' => { 'string' => 'string' } })
@@ -90,7 +90,7 @@ module Cbor
         end
 
         it 'builds union unit members as a type' do
-          union = structure_shape.member(:union).shape.member_type(:unit).new(unit: Schema::EmptyStructure.new)
+          union = structure_shape.member(:union).target.member_type(:unit).new(unit: Schema::EmptyStructure.new)
           type = structure_shape.type.new(union: union)
           bytes = subject.build(structure_shape, type)
           expect(Cbor.decode(bytes)).to eq('union' => { 'unit' => {} })
diff --git a/gems/smithy-client/lib/smithy-client/default_params.rb b/gems/smithy-client/lib/smithy-client/default_params.rb
index db3401bcf..8d879527b 100644
--- a/gems/smithy-client/lib/smithy-client/default_params.rb
+++ b/gems/smithy-client/lib/smithy-client/default_params.rb
@@ -22,7 +22,7 @@ def apply(params)
       private
 
       def shape(ref, value)
-        case ref.shape
+        case ref.target
         when ListShape then list(ref, value)
         when MapShape then map(ref, value)
         when StructureShape then structure(ref, value)
@@ -33,7 +33,7 @@ def shape(ref, value)
       def list(ref, values)
         return if values.nil?
 
-        shape = ref.shape
+        shape = ref.target
         values.each do |value|
           shape(shape.member, value)
         end
@@ -43,7 +43,7 @@ def list(ref, values)
       def map(ref, values)
         return if values.nil?
 
-        shape = ref.shape
+        shape = ref.target
         values.each_pair do |_key, value|
           shape(shape.value, value)
         end
@@ -53,7 +53,7 @@ def map(ref, values)
       def structure(ref, values)
         return if values.nil?
 
-        ref.shape.members.each do |member_name, member_ref|
+        ref.target.members.each do |member_name, member_ref|
           value = values[member_name]
           value ||= default(member_ref) if default?(ref, member_ref.traits)
           next if value.nil? && !default?(ref, member_ref.traits) # default can have nil values
@@ -72,7 +72,7 @@ def default?(ref, traits)
 
       def default(ref)
         default = ref.traits['smithy.api#default']
-        case ref.shape
+        case ref.target
         when BlobShape then Base64.strict_decode64(default)
         when TimestampShape then timestamp_default(default)
         else default
diff --git a/gems/smithy-client/lib/smithy-client/log_param_filter.rb b/gems/smithy-client/lib/smithy-client/log_param_filter.rb
index ebd00af84..551c9e849 100644
--- a/gems/smithy-client/lib/smithy-client/log_param_filter.rb
+++ b/gems/smithy-client/lib/smithy-client/log_param_filter.rb
@@ -11,7 +11,7 @@ def initialize(options = {})
       end
 
       def filter(ref, values)
-        case ref.shape
+        case ref.target
         when ListShape then list(ref, values)
         when MapShape then map(ref, values)
         when StructureShape then structure(ref, values)
@@ -23,7 +23,7 @@ def filter(ref, values)
       private
 
       def list(ref, values)
-        shape = ref.shape
+        shape = ref.target
         return '[FILTERED]' if sensitive?(shape)
 
         member_ref = shape.member
@@ -31,7 +31,7 @@ def list(ref, values)
       end
 
       def map(ref, values)
-        shape = ref.shape
+        shape = ref.target
         return '[FILTERED]' if sensitive?(shape)
 
         filtered = {}
@@ -43,13 +43,13 @@ def map(ref, values)
       end
 
       def scalar(ref, value)
-        return '[FILTERED]' if sensitive?(ref.shape)
+        return '[FILTERED]' if sensitive?(ref.target)
 
         value
       end
 
       def structure(ref, values)
-        shape = ref.shape
+        shape = ref.target
         return '[FILTERED]' if sensitive?(shape)
 
         filtered = {}
@@ -63,17 +63,17 @@ def structure(ref, values)
       end
 
       def union(ref, values) # rubocop:disable Metrics/AbcSize
-        shape = ref.shape
+        shape = ref.target
         return '[FILTERED]' if sensitive?(shape)
 
         filtered = {}
         if values.is_a?(Schema::Union)
-          name, member_ref = ref.shape.member_by_type(values.class)
+          name, member_ref = ref.target.member_by_type(values.class)
           filtered[name] = filter(member_ref, values.value)
         else
           key, value = values.first
-          if ref.shape.member?(key)
-            member_ref = ref.shape.member(key)
+          if ref.target.member?(key)
+            member_ref = ref.target.member(key)
             filtered[key] = filter(member_ref, value)
           end
         end
diff --git a/gems/smithy-client/lib/smithy-client/param_converter.rb b/gems/smithy-client/lib/smithy-client/param_converter.rb
index f89eb0237..a28633225 100644
--- a/gems/smithy-client/lib/smithy-client/param_converter.rb
+++ b/gems/smithy-client/lib/smithy-client/param_converter.rb
@@ -36,11 +36,11 @@ def close_opened_files
       private
 
       def c(ref, value)
-        self.class.c(ref.shape.class, value, self)
+        self.class.c(ref.target.class, value, self)
       end
 
       def shape(ref, value)
-        case ref.shape
+        case ref.target
         when ListShape then list(ref, value)
         when MapShape then map(ref, value)
         when StructureShape then structure(ref, value)
@@ -53,7 +53,7 @@ def list(ref, values)
         values = c(ref, values)
         return values unless values.is_a?(Array)
 
-        values.collect { |v| shape(ref.shape.member, v) }
+        values.collect { |v| shape(ref.target.member, v) }
       end
 
       def map(ref, values)
@@ -61,7 +61,7 @@ def map(ref, values)
         return values unless values.is_a?(Hash)
 
         values.each.with_object({}) do |(key, value), hash|
-          hash[shape(ref.shape.key, key)] = shape(ref.shape.value, value)
+          hash[shape(ref.target.key, key)] = shape(ref.target.value, value)
         end
       end
 
@@ -71,9 +71,9 @@ def structure(ref, values)
 
         values.each_pair do |k, v|
           next if v.nil?
-          next unless ref.shape.member?(k)
+          next unless ref.target.member?(k)
 
-          values[k] = shape(ref.shape.member(k), v)
+          values[k] = shape(ref.target.member(k), v)
         end
         values
       end
@@ -82,11 +82,11 @@ def union(ref, values)
         values = c(ref, values)
 
         if values.is_a?(Schema::Union)
-          _name, member_ref = ref.shape.member_by_type(values.class)
+          _name, member_ref = ref.target.member_by_type(values.class)
           values = shape(member_ref, values)
         elsif values.is_a?(Hash)
           key, value = values.first
-          values[key] = shape(ref.shape.member(key), value)
+          values[key] = shape(ref.target.member(key), value)
         end
         values
       end
diff --git a/gems/smithy-client/lib/smithy-client/param_validator.rb b/gems/smithy-client/lib/smithy-client/param_validator.rb
index 6959ebbc1..1bede2ab9 100644
--- a/gems/smithy-client/lib/smithy-client/param_validator.rb
+++ b/gems/smithy-client/lib/smithy-client/param_validator.rb
@@ -29,7 +29,7 @@ def validate!(params, context: 'params')
 
       # rubocop:disable Metrics
       def shape(ref, value, errors, context)
-        case ref.shape
+        case ref.target
         when StructureShape then structure(ref, value, errors, context)
         when ListShape then list(ref, value, errors, context)
         when MapShape then map(ref, value, errors, context)
@@ -96,7 +96,7 @@ def list(ref, values, errors, context)
         values.each.with_index do |value, index|
           next unless value
 
-          shape(ref.shape.member, value, errors, context + "[#{index}]")
+          shape(ref.target.member, value, errors, context + "[#{index}]")
         end
       end
 
@@ -107,16 +107,16 @@ def map(ref, values, errors, context)
         end
 
         values.each do |key, value|
-          shape(ref.shape.key, key, errors, "#{context} #{key.inspect} key")
+          shape(ref.target.key, key, errors, "#{context} #{key.inspect} key")
           next unless value
 
-          shape(ref.shape.value, value, errors, context + "[#{key.inspect}]")
+          shape(ref.target.value, value, errors, context + "[#{key.inspect}]")
         end
       end
 
       def member(ref, name, value, errors, context)
-        if ref.shape.member?(name)
-          member_ref = ref.shape.member(name)
+        if ref.target.member?(name)
+          member_ref = ref.target.member(name)
           shape(member_ref, value, errors, context + "[#{name.inspect}]")
         else
           errors << "unexpected value at #{context}[#{name.inspect}]"
@@ -124,7 +124,7 @@ def member(ref, name, value, errors, context)
       end
 
       def structure(ref, values, errors, context)
-        return if ref.shape == Prelude::Unit
+        return if ref.target == Prelude::Unit
         return unless valid_structure?(ref, values, errors, context)
 
         validate_required_members(ref, values, errors, context) if @validate_required
@@ -136,7 +136,7 @@ def structure(ref, values, errors, context)
       end
 
       def valid_structure?(ref, values, errors, context)
-        if !values.is_a?(Hash) && !values.is_a?(ref.shape.type)
+        if !values.is_a?(Hash) && !values.is_a?(ref.target.type)
           errors << expected_got(context, 'a Hash', values)
           return false
         end
@@ -148,7 +148,7 @@ def union(ref, values, errors, context)
         return unless valid_union?(ref, values, errors, context)
 
         if values.is_a?(Schema::Union)
-          _name, member_ref = ref.shape.member_by_type(values.class)
+          _name, member_ref = ref.target.member_by_type(values.class)
           shape(member_ref, values.value, errors, context)
         elsif values.is_a?(Hash)
           values.each_pair do |name, value|
@@ -160,7 +160,7 @@ def union(ref, values, errors, context)
       end
 
       def valid_union?(ref, values, errors, context)
-        return true if values.is_a?(ref.shape.type)
+        return true if values.is_a?(ref.target.type)
 
         unless values.is_a?(Hash)
           errors << expected_got(context, 'a Hash', values)
@@ -168,14 +168,14 @@ def valid_union?(ref, values, errors, context)
         end
         return true if values.size <= 1
 
-        union_members = ref.shape.members.keys.join(', ')
+        union_members = ref.target.members.keys.join(', ')
         error = "expected #{context} to be a Hash with one of #{union_members}, got #{values.size} keys instead."
         errors << error
         false
       end
 
       def validate_required_members(ref, values, errors, context)
-        ref.shape.members.each do |name, member_ref|
+        ref.target.members.each do |name, member_ref|
           traits = member_ref.traits
           next unless traits.key?('smithy.api#required') && !traits.key?('smithy.api#clientOptional')
 
@@ -187,7 +187,7 @@ def validate_required_members(ref, values, errors, context)
       end
 
       def streaming_input?(ref)
-        ref.shape.traits.key?('smithy.api#streaming')
+        ref.target.traits.key?('smithy.api#streaming')
       end
 
       def io_like?(value, require_size: false)
diff --git a/gems/smithy-client/lib/smithy-client/plugins/host_prefix.rb b/gems/smithy-client/lib/smithy-client/plugins/host_prefix.rb
index 0e174bd3e..769cae103 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/host_prefix.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/host_prefix.rb
@@ -51,7 +51,7 @@ def apply_host_prefix(context, host_prefix)
 
           def label_value(input, label, params)
             name = nil
-            input.shape.members.each do |member_name, member_ref|
+            input.target.members.each do |member_name, member_ref|
               next unless member_ref.traits.key?('smithy.api#hostLabel')
               next unless member_ref.location_name == label
 
diff --git a/gems/smithy-client/lib/smithy-client/plugins/idempotency_token.rb b/gems/smithy-client/lib/smithy-client/plugins/idempotency_token.rb
index 88505e12e..bd57b084b 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/idempotency_token.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/idempotency_token.rb
@@ -21,7 +21,7 @@ def call(context)
           private
 
           def apply_idempotency_token(input, params)
-            input.shape.members.each do |member_name, member_ref|
+            input.target.members.each do |member_name, member_ref|
               next unless member_ref.traits.key?('smithy.api#idempotencyToken')
 
               params[member_name] ||= SecureRandom.uuid
diff --git a/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb b/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb
index 953f3d57f..44ff7e27a 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb
@@ -92,9 +92,9 @@ def request_encoding_selection(context)
           end
 
           def streaming?(input)
-            input.shape.members.any? do |_, member_ref|
-              member_ref.shape.traits.key?('smithy.api#streaming') &&
-                !member_ref.shape.traits.key?('smithy.api#requiresLength')
+            input.target.members.any? do |_, member_ref|
+              member_ref.target.traits.key?('smithy.api#streaming') &&
+                !member_ref.target.traits.key?('smithy.api#requiresLength')
             end
           end
 
diff --git a/gems/smithy-client/lib/smithy-client/plugins/transfer_encoding.rb b/gems/smithy-client/lib/smithy-client/plugins/transfer_encoding.rb
index 13fef8c0e..823bcdca8 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/transfer_encoding.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/transfer_encoding.rb
@@ -13,7 +13,7 @@ class Handler < Client::Handler
           def call(context)
             payload_ref = streaming_member_ref(context)
             # Proceed with TE header logic IFF there's a streaming payload.
-            apply_transfer_encoding(context, payload_ref.shape) if payload_ref
+            apply_transfer_encoding(context, payload_ref.target) if payload_ref
             @handler.call(context)
           end
 
@@ -29,8 +29,8 @@ def apply_transfer_encoding(context, payload)
           end
 
           def streaming_member_ref(context)
-            context.operation.input.shape.members.detect do |_, ref|
-              ref.shape.traits.key?('smithy.api#streaming')
+            context.operation.input.target.members.detect do |_, ref|
+              ref.target.traits.key?('smithy.api#streaming')
             end&.last
           end
 
diff --git a/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/error_handler.rb b/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/error_handler.rb
index c693784bb..1da335e68 100644
--- a/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/error_handler.rb
+++ b/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/error_handler.rb
@@ -48,9 +48,9 @@ def extract_error(body, context)
         def parse_error_data(context, body, code)
           data = Schema::EmptyStructure.new
           context.operation.errors.each do |ref|
-            next unless ref.shape.name == code
+            next unless ref.target.name == code
 
-            data = Cbor::Parser.new.parse(ref, body, ref.shape.type.new)
+            data = Cbor::Parser.new.parse(ref, body, ref.target.type.new)
           end
           data
         end
diff --git a/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/handler.rb b/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/handler.rb
index cf5a58065..8f0f1a49c 100644
--- a/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/handler.rb
+++ b/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/handler.rb
@@ -36,7 +36,7 @@ def apply_content_type_header(context)
           content_type =
             if event_stream?(input)
               'application/vnd.amazon.eventstream'
-            elsif input.shape != Schema::Shapes::Prelude::Unit
+            elsif input.target != Schema::Shapes::Prelude::Unit
               'application/cbor'
             end
 
@@ -65,8 +65,8 @@ def apply_url_path(context)
         end
 
         def event_stream?(ref)
-          ref.shape.members.each_value do |member_ref|
-            shape = member_ref.shape
+          ref.target.members.each_value do |member_ref|
+            shape = member_ref.target
             return true if shape.traits.key?('smithy.api#streaming') && shape.is_a?(Schema::Shapes::UnionShape)
           end
           false
diff --git a/gems/smithy-client/lib/smithy-client/stubbing/data_applicator.rb b/gems/smithy-client/lib/smithy-client/stubbing/data_applicator.rb
index 402ac33c5..2ea15052c 100644
--- a/gems/smithy-client/lib/smithy-client/stubbing/data_applicator.rb
+++ b/gems/smithy-client/lib/smithy-client/stubbing/data_applicator.rb
@@ -19,7 +19,7 @@ def apply(data, stub)
         private
 
         def shape(ref, value, stub = nil)
-          case ref.shape
+          case ref.target
           when StructureShape then structure(ref, value, stub)
           when ListShape then list(ref, value)
           when MapShape then map(ref, value)
@@ -30,7 +30,7 @@ def shape(ref, value, stub = nil)
         def list(ref, value)
           return if value.nil?
 
-          shape = ref.shape
+          shape = ref.target
           value.each_with_object([]) do |v, list|
             list << shape(shape.member, v)
           end
@@ -39,7 +39,7 @@ def list(ref, value)
         def map(ref, value)
           return if value.nil?
 
-          shape = ref.shape
+          shape = ref.target
           value.each_with_object({}) do |(k, v), map|
             map[k.to_s] = shape(shape.value, v)
           end
@@ -48,8 +48,8 @@ def map(ref, value)
         def structure(ref, data, stub)
           return if data.nil?
 
-          stub = ref.shape.type.new if stub.nil?
-          shape = ref.shape
+          stub = ref.target.type.new if stub.nil?
+          shape = ref.target
           data.each_pair do |key, value|
             stub[key] = shape(shape.member(key), value)
           end
diff --git a/gems/smithy-client/lib/smithy-client/stubbing/empty_stub.rb b/gems/smithy-client/lib/smithy-client/stubbing/empty_stub.rb
index ef18755f5..ed1de27d0 100644
--- a/gems/smithy-client/lib/smithy-client/stubbing/empty_stub.rb
+++ b/gems/smithy-client/lib/smithy-client/stubbing/empty_stub.rb
@@ -22,7 +22,7 @@ def stub
         private
 
         def shape(ref, visited)
-          shape = ref.shape
+          shape = ref.target
           return nil if visited.include?(shape)
 
           visited += [shape]
@@ -37,14 +37,14 @@ def shape(ref, visited)
         end
 
         def structure(ref, visited)
-          shape = ref.shape
+          shape = ref.target
           shape.members.each_with_object(shape.type.new) do |(member_name, member_ref), struct|
             struct[member_name] = shape(member_ref, visited)
           end
         end
 
         def union(ref, visited)
-          shape = ref.shape
+          shape = ref.target
           member_name, member_ref = shape.members.first
           return unless member_name
 
@@ -54,7 +54,7 @@ def union(ref, visited)
         end
 
         def scalar(ref)
-          case ref.shape
+          case ref.target
           when BigDecimalShape then BigDecimal(0)
           when BlobShape, EnumShape, StringShape then ref.location_name
           when BooleanShape then false
diff --git a/gems/smithy-client/spec/smithy-client/log_param_filter_spec.rb b/gems/smithy-client/spec/smithy-client/log_param_filter_spec.rb
index e7892b72e..c18d2b3c3 100644
--- a/gems/smithy-client/spec/smithy-client/log_param_filter_spec.rb
+++ b/gems/smithy-client/spec/smithy-client/log_param_filter_spec.rb
@@ -35,7 +35,7 @@ module Client
             'target' => 'smithy.ruby.tests#SensitiveStructure'
           }
 
-          sensitive_structure = input.shape.member(:sensitive_structure).shape.type
+          sensitive_structure = input.target.member(:sensitive_structure).target.type
           filtered = subject.filter(input, { sensitive_structure: sensitive_structure.new(string: 'sensitive') })
           expect(filtered).to eq(sensitive_structure: '[FILTERED]')
         end
@@ -120,7 +120,7 @@ module Client
 
         it 'filters sensitive unions as a type' do
           shapes['smithy.ruby.tests#Union']['traits'] = { 'smithy.api#sensitive' => {} }
-          union = input.shape.member(:union).shape.member_type(:string)
+          union = input.target.member(:union).target.member_type(:string)
           filtered = subject.filter(input, { union: union.new(string: 'sensitive') })
           expect(filtered).to eq(union: '[FILTERED]')
         end
diff --git a/gems/smithy-client/spec/smithy-client/param_converter_spec.rb b/gems/smithy-client/spec/smithy-client/param_converter_spec.rb
index 1f525e1e8..87d7dc9f8 100644
--- a/gems/smithy-client/spec/smithy-client/param_converter_spec.rb
+++ b/gems/smithy-client/spec/smithy-client/param_converter_spec.rb
@@ -49,8 +49,8 @@ module Client
         end
 
         it 'performs a deeply nested conversion of values when using types' do
-          structure_type = input.shape.type
-          union_type = input.shape.member(:union).shape.member_type(:structure)
+          structure_type = input.target.type
+          union_type = input.target.member(:union).target.member_type(:structure)
           params = structure_type.new(
             structure: structure_type.new(boolean: 'true'),
             map: 'not a map',
diff --git a/gems/smithy-client/spec/smithy-client/plugins/transfer_encoding_spec.rb b/gems/smithy-client/spec/smithy-client/plugins/transfer_encoding_spec.rb
index 215f660d8..664420d2b 100644
--- a/gems/smithy-client/spec/smithy-client/plugins/transfer_encoding_spec.rb
+++ b/gems/smithy-client/spec/smithy-client/plugins/transfer_encoding_spec.rb
@@ -25,8 +25,8 @@ module Plugins
         let(:streaming_body_plugin) do
           handler_class = Class.new(Client::Handler) do
             def call(context)
-              context.operation.input.shape.members.each do |name, ref|
-                if ref.shape.traits.key?('smithy.api#streaming') && context.params[name.to_sym]
+              context.operation.input.target.members.each do |name, ref|
+                if ref.target.traits.key?('smithy.api#streaming') && context.params[name.to_sym]
                   context.http_request.body = context.params[name.to_sym]
                   break
                 end
diff --git a/gems/smithy-json/lib/smithy-json/builder.rb b/gems/smithy-json/lib/smithy-json/builder.rb
index c55cf456d..1d7b846c9 100644
--- a/gems/smithy-json/lib/smithy-json/builder.rb
+++ b/gems/smithy-json/lib/smithy-json/builder.rb
@@ -13,14 +13,14 @@ def initialize(options = {})
       end
 
       def build(shape, data)
-        ref = shape.is_a?(ShapeRef) ? shape : ShapeRef.new(shape: shape)
+        ref = shape.is_a?(MemberShape) ? shape : MemberShape.new(target: shape)
         Smithy::Json.dump(shape(ref, data))
       end
 
       private
 
       def shape(ref, value) # rubocop:disable Metrics/CyclomaticComplexity
-        case ref.shape
+        case ref.target
         when BlobShape then blob(value)
         when FloatShape then float(value)
         when ListShape then list(ref, value)
@@ -51,7 +51,7 @@ def float(value)
       def list(ref, values)
         return if values.nil?
 
-        shape = ref.shape
+        shape = ref.target
         values.collect do |value|
           shape(shape.member, value)
         end
@@ -60,7 +60,7 @@ def list(ref, values)
       def map(ref, values)
         return if values.nil?
 
-        shape = ref.shape
+        shape = ref.target
         values.each.with_object({}) do |(key, value), data|
           data[key] = shape(shape.value, value)
         end
@@ -69,7 +69,7 @@ def map(ref, values)
       def structure(ref, values)
         return if values.nil?
 
-        ref.shape.members.each_with_object({}) do |(member_name, member_ref), data|
+        ref.target.members.each_with_object({}) do |(member_name, member_ref), data|
           value = values[member_name]
           data[location_name(member_ref)] = shape(member_ref, value) unless value.nil?
         end
@@ -77,7 +77,7 @@ def structure(ref, values)
 
       def timestamp(ref, value)
         trait = 'smithy.api#timestampFormat'
-        case ref.traits[trait] || ref.shape.traits[trait]
+        case ref.traits[trait] || ref.target.traits[trait]
         when 'date-time' then value.utc.iso8601
         when 'http-date' then value.utc.httpdate
         else
@@ -91,12 +91,12 @@ def union(ref, values) # rubocop:disable Metrics/AbcSize
 
         data = {}
         if values.is_a?(Schema::Union)
-          _name, member_ref = ref.shape.member_by_type(values.class)
+          _name, member_ref = ref.target.member_by_type(values.class)
           data[location_name(member_ref)] = shape(member_ref, values.value)
         else
           key, value = values.first
-          if ref.shape.member?(key)
-            member_ref = ref.shape.member(key)
+          if ref.target.member?(key)
+            member_ref = ref.target.member(key)
             data[location_name(member_ref)] = shape(member_ref, value)
           end
         end
diff --git a/gems/smithy-json/lib/smithy-json/codec.rb b/gems/smithy-json/lib/smithy-json/codec.rb
index 82e8abd25..c808dfc4a 100644
--- a/gems/smithy-json/lib/smithy-json/codec.rb
+++ b/gems/smithy-json/lib/smithy-json/codec.rb
@@ -9,14 +9,14 @@ def initialize(options = {})
         @options = options
       end
 
-      # @param [ShapeRef, Shape] shape
+      # @param [MemberShape, Shape] shape
       # @param [Object] data
       # @return [String, nil]
       def build(shape, data)
         Builder.new(@options).build(shape, data)
       end
 
-      # @param [ShapeRef, Shape] shape
+      # @param [MemberShape, Shape] shape
       # @param [String] bytes
       # @param [Object, nil] target (nil)
       # @return [Object, nil]
diff --git a/gems/smithy-json/lib/smithy-json/parser.rb b/gems/smithy-json/lib/smithy-json/parser.rb
index e21c05c6a..a99e8d0b4 100644
--- a/gems/smithy-json/lib/smithy-json/parser.rb
+++ b/gems/smithy-json/lib/smithy-json/parser.rb
@@ -15,14 +15,14 @@ def initialize(options = {})
       def parse(shape, bytes, target = nil)
         return {} if bytes.empty?
 
-        ref = shape.is_a?(ShapeRef) ? shape : ShapeRef.new(shape: shape)
+        ref = shape.is_a?(MemberShape) ? shape : MemberShape.new(target: shape)
         shape(ref, Smithy::Json.load(bytes), target)
       end
 
       private
 
       def shape(ref, value, target = nil) # rubocop:disable Metrics/CyclomaticComplexity
-        case ref.shape
+        case ref.target
         when BlobShape then Base64.decode64(value)
         when FloatShape then float(value)
         when ListShape then list(ref, value, target)
@@ -48,9 +48,9 @@ def list(ref, values, target = nil)
 
         target = [] if target.nil?
         values.each do |value|
-          next if value.nil? && !sparse?(ref.shape)
+          next if value.nil? && !sparse?(ref.target)
 
-          target << shape(ref.shape.member, value)
+          target << shape(ref.target.member, value)
         end
         target
       end
@@ -58,9 +58,9 @@ def list(ref, values, target = nil)
       def map(ref, values, target = nil)
         target = {} if target.nil?
         values.each do |key, value|
-          next if value.nil? && !sparse?(ref.shape)
+          next if value.nil? && !sparse?(ref.target)
 
-          target[key] = shape(ref.shape.value, value)
+          target[key] = shape(ref.target.value, value)
         end
         target
       end
@@ -68,8 +68,8 @@ def map(ref, values, target = nil)
       def structure(ref, values, target = nil)
         return if values.nil?
 
-        target = ref.shape.type.new if target.nil?
-        ref.shape.members.each do |member_name, member_ref|
+        target = ref.target.type.new if target.nil?
+        ref.target.members.each do |member_name, member_ref|
           value = values[location_name(member_ref)]
           target[member_name] = shape(member_ref, value) unless value.nil?
         end
@@ -90,17 +90,17 @@ def timestamp(value)
       end
 
       def union(ref, values, target = nil) # rubocop:disable Metrics/AbcSize
-        ref.shape.members.each do |member_name, member_ref|
+        ref.target.members.each do |member_name, member_ref|
           value = values[location_name(member_ref)]
           next if value.nil?
 
-          target = ref.shape.member_type(member_name) if target.nil?
+          target = ref.target.member_type(member_name) if target.nil?
           return target.new(member_name => shape(member_ref, value))
         end
 
         values.delete('__type')
         key, value = values.first
-        ref.shape.member_type(:unknown).new(unknown: { key => value })
+        ref.target.member_type(:unknown).new(unknown: { key => value })
       end
 
       def location_name(ref)
diff --git a/gems/smithy-json/sig/smithy-json/codec.rbs b/gems/smithy-json/sig/smithy-json/codec.rbs
index 0c5b60994..5d55bff0f 100644
--- a/gems/smithy-json/sig/smithy-json/codec.rbs
+++ b/gems/smithy-json/sig/smithy-json/codec.rbs
@@ -2,8 +2,8 @@ module Smithy
   module Json
     class Codec
       def initialize: (?Hash[Symbol, untyped] options) -> void
-      def build: (Schema::Shapes::Shape | Schema::Shapes::ShapeRef shape, Object data) -> (nil | String)
-      def parse: (Schema::Shapes::Shape | Schema::Shapes::ShapeRef shape, String bytes, ?Object ?target) -> Object?
+      def build: (Schema::Shapes::Shape | Schema::Shapes::MemberShape shape, Object data) -> (nil | String)
+      def parse: (Schema::Shapes::Shape | Schema::Shapes::MemberShape shape, String bytes, ?Object ?target) -> Object?
     end
   end
 end
\ No newline at end of file
diff --git a/gems/smithy-json/spec/smithy-json/builder_spec.rb b/gems/smithy-json/spec/smithy-json/builder_spec.rb
index 821a656c1..08f286eb3 100644
--- a/gems/smithy-json/spec/smithy-json/builder_spec.rb
+++ b/gems/smithy-json/spec/smithy-json/builder_spec.rb
@@ -90,7 +90,7 @@ module Json
 
       context 'unions' do
         it 'builds unions as a type' do
-          union = structure_shape.member(:union).shape.member_type(:string).new(string: 'string')
+          union = structure_shape.member(:union).target.member_type(:string).new(string: 'string')
           type = structure_shape.type.new(union: union)
           bytes = subject.build(structure_shape, type)
           expect(Json.load(bytes)).to eq({ 'union' => { 'string' => 'string' } })
@@ -103,7 +103,7 @@ module Json
         end
 
         it 'builds union unit members as a type' do
-          union = structure_shape.member(:union).shape.member_type(:unit).new(unit: Schema::EmptyStructure.new)
+          union = structure_shape.member(:union).target.member_type(:unit).new(unit: Schema::EmptyStructure.new)
           type = structure_shape.type.new(union: union)
           bytes = subject.build(structure_shape, type)
           expect(Json.load(bytes)).to eq('union' => { 'unit' => {} })
diff --git a/gems/smithy-schema/lib/smithy-schema/document_utils/deserializer.rb b/gems/smithy-schema/lib/smithy-schema/document_utils/deserializer.rb
index 7104a1f34..d4b5635fd 100644
--- a/gems/smithy-schema/lib/smithy-schema/document_utils/deserializer.rb
+++ b/gems/smithy-schema/lib/smithy-schema/document_utils/deserializer.rb
@@ -13,14 +13,14 @@ def initialize(options = {})
         end
 
         def deserialize(data, shape, target)
-          ref = shape.is_a?(ShapeRef) ? shape : ShapeRef.new(shape: shape)
+          ref = shape.is_a?(MemberShape) ? shape : MemberShape.new(target: shape)
           shape(ref, data, target)
         end
 
         private
 
         def shape(ref, value, target = nil) # rubocop:disable Metrics/CyclomaticComplexity
-          case ref.shape
+          case ref.target
           when BlobShape then Base64.strict_decode64(value)
           when DocumentShape then document(value)
           when FloatShape then float(value)
@@ -39,7 +39,7 @@ def document(values)
           msg = 'invalid document - document discriminator not found in type registry'
           raise ArgumentError, msg unless @type_registry.key?(values['__type'])
 
-          shape(ShapeRef.new(shape: @type_registry[values['__type']]), values)
+          shape(MemberShape.new(target: @type_registry[values['__type']]), values)
         end
 
         def float(value)
@@ -57,7 +57,7 @@ def list(ref, values, target = nil)
 
           target = [] if target.nil?
           values.each do |value|
-            target << shape(ref.shape.member, value) unless value.nil?
+            target << shape(ref.target.member, value) unless value.nil?
           end
           target
         end
@@ -67,7 +67,7 @@ def map(ref, values, target = nil)
 
           target = {} if target.nil?
           values.each do |key, value|
-            target[key] = shape(ref.shape.value, value) unless value.nil?
+            target[key] = shape(ref.target.value, value) unless value.nil?
           end
           target
         end
@@ -75,8 +75,8 @@ def map(ref, values, target = nil)
         def structure(ref, values, target = nil)
           return if values.nil?
 
-          target = ref.shape.type.new if target.nil?
-          ref.shape.members.each do |member_name, member_ref|
+          target = ref.target.type.new if target.nil?
+          ref.target.members.each do |member_name, member_ref|
             value = values[location_name(member_ref)]
             target[member_name] = shape(member_ref, value) unless value.nil?
           end
@@ -101,17 +101,17 @@ def timestamp(value)
         end
 
         def union(ref, values, target = nil) # rubocop:disable Metrics/AbcSize
-          ref.shape.members.each do |member_name, member_ref|
+          ref.target.members.each do |member_name, member_ref|
             value = values[location_name(member_ref)]
             next if value.nil?
 
-            target = ref.shape.member_type(member_name) if target.nil?
+            target = ref.target.member_type(member_name) if target.nil?
             return target.new(member_name => shape(member_ref, value))
           end
 
           values.delete('__type')
           key, value = values.first
-          ref.shape.member_type(:unknown).new(key, value)
+          ref.target.member_type(:unknown).new(key, value)
         end
 
         def location_name(ref)
diff --git a/gems/smithy-schema/lib/smithy-schema/document_utils/serializer.rb b/gems/smithy-schema/lib/smithy-schema/document_utils/serializer.rb
index 3f98dfe21..7be3e0edf 100644
--- a/gems/smithy-schema/lib/smithy-schema/document_utils/serializer.rb
+++ b/gems/smithy-schema/lib/smithy-schema/document_utils/serializer.rb
@@ -19,7 +19,7 @@ def initialize(options = {})
         end
 
         def format_document_data(shape, data)
-          ref = shape.is_a?(ShapeRef) ? shape : ShapeRef.new(shape: shape)
+          ref = shape.is_a?(MemberShape) ? shape : MemberShape.new(target: shape)
           document_data = shape(ref, data)
           document_data['__type'] = shape.id
           document_data
@@ -42,7 +42,7 @@ def serialize_untyped(values)
         private
 
         def shape(ref, values) # rubocop:disable Metrics/CyclomaticComplexity
-          case ref.shape
+          case ref.target
           when BlobShape then blob(values)
           when DocumentShape then document(values)
           when FloatShape then float(values)
@@ -92,7 +92,7 @@ def float(value)
         def list(ref, values)
           return if values.nil?
 
-          shape = ref.shape
+          shape = ref.target
           values.collect do |value|
             shape(shape.member, value)
           end
@@ -101,7 +101,7 @@ def list(ref, values)
         def map(ref, values)
           return if values.nil?
 
-          shape = ref.shape
+          shape = ref.target
           values.each.with_object({}) do |(key, value), data|
             data[key.to_s] = shape(shape.value, value)
           end
@@ -110,7 +110,7 @@ def map(ref, values)
         def structure(ref, values)
           return if values.nil?
 
-          ref.shape.members.each_with_object({}) do |(member_name, member_ref), data|
+          ref.target.members.each_with_object({}) do |(member_name, member_ref), data|
             value = resolve_value(member_name, member_ref, values.to_h)
             data[location_name(member_ref)] = shape(member_ref, value) unless value.nil?
           end
@@ -121,7 +121,7 @@ def timestamp(ref, value)
           return value.to_i unless @timestamp_format
 
           trait = 'smithy.api#timestampFormat'
-          case ref.traits[trait] || ref.shape.traits[trait]
+          case ref.traits[trait] || ref.target.traits[trait]
           when 'date-time' then value.utc.iso8601
           when 'http-date' then value.utc.httpdate
           else
@@ -135,7 +135,7 @@ def union(ref, values)
 
           data = {}
           if values.is_a?(Union)
-            _name, member_ref = ref.shape.member_by_type(values.class)
+            _name, member_ref = ref.target.member_by_type(values.class)
             data[location_name(member_ref)] = shape(member_ref, values)
           else
             key, value = values.first
@@ -161,9 +161,9 @@ def normalize_timestamp_value(value)
         end
 
         def resolve_member_ref(ref, name)
-          return ref.shape.member(name) if ref.shape.member?(name)
+          return ref.target.member(name) if ref.target.member?(name)
 
-          ref.shape.members.values.find do |member_ref|
+          ref.target.members.values.find do |member_ref|
             member_ref.traits['smithy.api#jsonName'] == name || member_ref.location_name == name
           end
         end
diff --git a/gems/smithy-schema/lib/smithy-schema/shapes.rb b/gems/smithy-schema/lib/smithy-schema/shapes.rb
index caa8e94ba..d78c517dc 100644
--- a/gems/smithy-schema/lib/smithy-schema/shapes.rb
+++ b/gems/smithy-schema/lib/smithy-schema/shapes.rb
@@ -35,16 +35,16 @@ def []=(key, value)
       end
 
       # A reference to a shape.
-      class ShapeRef
+      class MemberShape
         def initialize(options = {})
-          @shape = options[:shape]
+          @target = options[:target]
           @location_name = options[:location_name]
           @traits = options[:traits] || {}
           @metadata = {}
         end
 
         # @return [Shape]
-        attr_accessor :shape
+        attr_accessor :target
 
         # @return [String, nil]
         attr_accessor :location_name
@@ -123,13 +123,13 @@ def initialize(options = {})
         # @return [String]
         attr_accessor :name
 
-        # @return [ShapeRef]
+        # @return [MemberShape]
         attr_accessor :input
 
-        # @return [ShapeRef]
+        # @return [MemberShape]
         attr_accessor :output
 
-        # @return [Array<ShapeRef>]
+        # @return [Array<MemberShape>]
         attr_accessor :errors
       end
 
@@ -152,10 +152,10 @@ def initialize(options = {})
           @members = {}
         end
 
-        # @return [Hash<Symbol, ShapeRef>]
+        # @return [Hash<Symbol, MemberShape>]
         attr_accessor :members
 
-        # @return [ShapeRef]
+        # @return [MemberShape]
         def add_member(name, shape_ref)
           @members[name] = shape_ref
         end
@@ -167,7 +167,7 @@ def member?(name)
         end
 
         # @param [Symbol] name
-        # @return [ShapeRef, nil]
+        # @return [MemberShape, nil]
         def member(name)
           @members[name]
         end
@@ -186,10 +186,10 @@ def initialize(options = {})
           @members = {}
         end
 
-        # @return [Hash<Symbol, ShapeRef>]
+        # @return [Hash<Symbol, MemberShape>]
         attr_accessor :members
 
-        # @return [ShapeRef]
+        # @return [MemberShape]
         def add_member(name, shape_ref)
           @members[name] = shape_ref
         end
@@ -201,7 +201,7 @@ def member?(name)
         end
 
         # @param [Symbol] name
-        # @return [ShapeRef, nil]
+        # @return [MemberShape, nil]
         def member(name)
           @members[name]
         end
@@ -209,16 +209,16 @@ def member(name)
 
       # Represents a List shape.
       class ListShape < Shape
-        # @return [ShapeRef]
+        # @return [MemberShape]
         attr_accessor :member
       end
 
       # Represents a Map shape.
       class MapShape < Shape
-        # @return [ShapeRef]
+        # @return [MemberShape]
         attr_accessor :key
 
-        # @return [ShapeRef]
+        # @return [MemberShape]
         attr_accessor :value
       end
 
@@ -232,13 +232,13 @@ def initialize(options = {})
           @members = {}
         end
 
-        # @return [Hash<Symbol, ShapeRef>]
+        # @return [Hash<Symbol, MemberShape>]
         attr_accessor :members
 
         # @return [Class]
         attr_accessor :type
 
-        # @return [ShapeRef]
+        # @return [MemberShape]
         def add_member(name, shape_ref)
           @members[name] = shape_ref
         end
@@ -250,7 +250,7 @@ def member?(name)
         end
 
         # @param [Symbol] name
-        # @return [ShapeRef, nil]
+        # @return [MemberShape, nil]
         def member(name)
           @members[name]
         end
@@ -268,19 +268,19 @@ def initialize(options = {})
           @members_by_type = {}
         end
 
-        # @return [Hash<Symbol, ShapeRef>]
+        # @return [Hash<Symbol, MemberShape>]
         attr_accessor :members
 
         # @return [Hash<Symbol, Class>]
         attr_accessor :member_types
 
-        # @return [Hash<Class, [String, ShapeRef]>]
+        # @return [Hash<Class, [String, MemberShape]>]
         attr_accessor :members_by_type
 
         # @return [Class]
         attr_accessor :type
 
-        # @return [ShapeRef]
+        # @return [MemberShape]
         def add_member(name, type, shape_ref)
           @member_types[name] = type
           @members_by_type[type] = [name, shape_ref]
@@ -294,7 +294,7 @@ def member?(name)
         end
 
         # @param [Symbol] name
-        # @return [ShapeRef, nil]
+        # @return [MemberShape, nil]
         def member(name)
           @members[name]
         end
@@ -318,7 +318,7 @@ def member_by_type?(type)
         end
 
         # @param [Class] type
-        # @return [ShapeRef, nil]
+        # @return [MemberShape, nil]
         def member_by_type(type)
           @members_by_type[type]
         end
diff --git a/gems/smithy-schema/sig/smithy-schema/shapes.rbs b/gems/smithy-schema/sig/smithy-schema/shapes.rbs
index b21661af6..d1fe31fc9 100644
--- a/gems/smithy-schema/sig/smithy-schema/shapes.rbs
+++ b/gems/smithy-schema/sig/smithy-schema/shapes.rbs
@@ -11,10 +11,10 @@ module Smithy
         def []=: (Symbol, Object) -> void
       end
 
-      class ShapeRef
+      class MemberShape
         def initialize: (?Hash[Symbol, untyped]) -> void
 
-        attr_accessor shape: Shape
+        attr_accessor target: Shape
         attr_accessor location_name: String?
         attr_accessor traits: Hash[String, untyped]
         def []: (Symbol) -> Object
@@ -33,9 +33,9 @@ module Smithy
 
       class OperationShape < Shape
         attr_accessor name: String
-        attr_accessor input: ShapeRef
-        attr_accessor output: ShapeRef
-        attr_accessor errors: Array[ShapeRef]
+        attr_accessor input: MemberShape
+        attr_accessor output: MemberShape
+        attr_accessor errors: Array[MemberShape]
       end
 
       class BigDecimalShape < Shape
@@ -51,60 +51,60 @@ module Smithy
       end
 
       class EnumShape < Shape
-        attr_accessor members: Hash[Symbol, ShapeRef]
-        def add_member: (Symbol, ShapeRef) -> ShapeRef
+        attr_accessor members: Hash[Symbol, MemberShape]
+        def add_member: (Symbol, MemberShape) -> MemberShape
         def member?: (Symbol?) -> bool
-        def member: (Symbol) -> ShapeRef?
+        def member: (Symbol) -> MemberShape?
       end
 
       class IntegerShape < Shape
       end
 
       class IntEnumShape < Shape
-        attr_accessor members: Hash[Symbol, ShapeRef]
-        def add_member: (Symbol, ShapeRef) -> ShapeRef
+        attr_accessor members: Hash[Symbol, MemberShape]
+        def add_member: (Symbol, MemberShape) -> MemberShape
         def member?: (Symbol?) -> bool
-        def member: (Symbol) -> ShapeRef?
+        def member: (Symbol) -> MemberShape?
       end
 
       class FloatShape < Shape
       end
 
       class ListShape < Shape
-        attr_accessor member: ShapeRef
+        attr_accessor member: MemberShape
       end
 
       class MapShape < Shape
-        attr_accessor key: ShapeRef
-        attr_accessor value: ShapeRef
+        attr_accessor key: MemberShape
+        attr_accessor value: MemberShape
       end
 
       class StringShape < Shape
       end
 
       class StructureShape < Shape
-        attr_accessor members: Hash[Symbol, ShapeRef]
+        attr_accessor members: Hash[Symbol, MemberShape]
         attr_accessor type: Class | Struct[untyped]
-        def add_member: (Symbol, ShapeRef) -> ShapeRef
+        def add_member: (Symbol, MemberShape) -> MemberShape
         def member?: (Symbol?) -> bool
-        def member: (Symbol) -> ShapeRef?
+        def member: (Symbol) -> MemberShape?
       end
 
       class TimestampShape < Shape
       end
 
       class UnionShape < Shape
-        attr_accessor members: Hash[Symbol, ShapeRef]
+        attr_accessor members: Hash[Symbol, MemberShape]
         attr_accessor member_types: Hash[Symbol, Class]
-        attr_accessor members_by_type: Hash[Class, [Symbol, ShapeRef]]
+        attr_accessor members_by_type: Hash[Class, [Symbol, MemberShape]]
         attr_accessor type: Class | Struct[untyped]
-        def add_member: (Symbol, Class, ShapeRef) -> ShapeRef
+        def add_member: (Symbol, Class, MemberShape) -> MemberShape
         def member?: (Symbol?) -> bool
-        def member: (Symbol) -> ShapeRef?
+        def member: (Symbol) -> MemberShape?
         def member_type?: (Symbol) -> bool
         def member_type: (Symbol) -> Class?
         def member_by_type?: (Class) -> bool
-        def member_by_type: (Class) -> [Symbol, ShapeRef]?
+        def member_by_type: (Class) -> [Symbol, MemberShape]?
       end
 
       module Prelude
diff --git a/gems/smithy-schema/spec/smithy-schema/shapes_spec.rb b/gems/smithy-schema/spec/smithy-schema/shapes_spec.rb
index 9ac332fa2..feffeb7c3 100644
--- a/gems/smithy-schema/spec/smithy-schema/shapes_spec.rb
+++ b/gems/smithy-schema/spec/smithy-schema/shapes_spec.rb
@@ -40,17 +40,17 @@ module Shapes
         end
       end
 
-      describe ShapeRef do
-        subject { ShapeRef.new }
+      describe MemberShape do
+        subject { MemberShape.new }
 
         it 'defaults shape to nil' do
-          expect(subject.shape).to be_nil
+          expect(subject.target).to be_nil
         end
 
         it 'can reference a shape' do
           shape = Shape.new
-          subject = ShapeRef.new(shape: shape)
-          expect(subject.shape).to be(shape)
+          subject = MemberShape.new(target: shape)
+          expect(subject.target).to be(shape)
         end
 
         it 'defaults a location name to nil' do
@@ -58,7 +58,7 @@ module Shapes
         end
 
         it 'stores a location name' do
-          subject = ShapeRef.new(location_name: 'foo')
+          subject = MemberShape.new(location_name: 'foo')
           expect(subject.location_name).to eq('foo')
         end
 
@@ -67,7 +67,7 @@ module Shapes
         end
 
         it 'can get and set metadata' do
-          subject = ShapeRef.new
+          subject = MemberShape.new
           subject[:foo] = 'bar'
           expect(subject[:foo]).to eq('bar')
         end
@@ -152,7 +152,7 @@ module Shapes
       describe OperationShape do
         subject { OperationShape.new }
 
-        let(:shape_ref) { ShapeRef.new(shape: StructureShape.new) }
+        let(:shape_ref) { MemberShape.new(target: StructureShape.new) }
 
         it 'is a subclass of Shape' do
           expect(subject).to be_kind_of(Shape)
@@ -244,15 +244,15 @@ module Shapes
 
         describe '#add_member' do
           it 'adds a member reference' do
-            shape_ref = ShapeRef.new(shape: StringShape.new)
+            shape_ref = MemberShape.new(target: StringShape.new)
             subject.add_member(:foo, shape_ref)
-            expect(subject.members[:foo]).to be_kind_of(ShapeRef)
+            expect(subject.members[:foo]).to be_kind_of(MemberShape)
           end
         end
 
         describe '#member?' do
           it 'returns true if member exists' do
-            shape_ref = ShapeRef.new(shape: StringShape.new)
+            shape_ref = MemberShape.new(target: StringShape.new)
             subject.add_member(:foo, shape_ref)
             expect(subject.member?(:foo)).to be(true)
           end
@@ -260,9 +260,9 @@ module Shapes
 
         describe '#member' do
           it 'returns the member' do
-            shape_ref = ShapeRef.new(shape: StringShape.new)
+            shape_ref = MemberShape.new(target: StringShape.new)
             subject.add_member(:foo, shape_ref)
-            expect(subject.member(:foo)).to be_kind_of(ShapeRef)
+            expect(subject.member(:foo)).to be_kind_of(MemberShape)
           end
         end
       end
@@ -288,15 +288,15 @@ module Shapes
 
         describe '#add_member' do
           it 'adds a member reference' do
-            shape_ref = ShapeRef.new(shape: StringShape.new)
+            shape_ref = MemberShape.new(target: StringShape.new)
             subject.add_member(:foo, shape_ref)
-            expect(subject.members[:foo]).to be_kind_of(ShapeRef)
+            expect(subject.members[:foo]).to be_kind_of(MemberShape)
           end
         end
 
         describe '#member?' do
           it 'returns true if member exists' do
-            shape_ref = ShapeRef.new(shape: StringShape.new)
+            shape_ref = MemberShape.new(target: StringShape.new)
             subject.add_member(:foo, shape_ref)
             expect(subject.member?(:foo)).to be(true)
           end
@@ -304,9 +304,9 @@ module Shapes
 
         describe '#member' do
           it 'returns the member' do
-            shape_ref = ShapeRef.new(shape: StringShape.new)
+            shape_ref = MemberShape.new(target: StringShape.new)
             subject.add_member(:foo, shape_ref)
-            expect(subject.member(:foo)).to be_kind_of(ShapeRef)
+            expect(subject.member(:foo)).to be_kind_of(MemberShape)
           end
         end
       end
@@ -334,7 +334,7 @@ module Shapes
 
         describe '#member accessor' do
           it 'gets and sets a member' do
-            shape_ref = ShapeRef.new(shape: StringShape.new)
+            shape_ref = MemberShape.new(target: StringShape.new)
             subject.member = shape_ref
             expect(subject.member).to eq(shape_ref)
           end
@@ -360,7 +360,7 @@ module Shapes
 
         describe '#key accessor' do
           it 'gets and sets a key' do
-            shape_ref = ShapeRef.new(shape: StringShape.new)
+            shape_ref = MemberShape.new(target: StringShape.new)
             subject.key = shape_ref
             expect(subject.key).to eq(shape_ref)
           end
@@ -368,7 +368,7 @@ module Shapes
 
         describe '#value accessor' do
           it 'gets and sets a value' do
-            shape_ref = ShapeRef.new(shape: StringShape.new)
+            shape_ref = MemberShape.new(target: StringShape.new)
             subject.value = shape_ref
             expect(subject.value).to eq(shape_ref)
           end
@@ -403,15 +403,15 @@ module Shapes
 
         describe '#add_member' do
           it 'adds a member reference' do
-            shape_ref = ShapeRef.new(shape: StringShape.new)
+            shape_ref = MemberShape.new(target: StringShape.new)
             subject.add_member(:foo, shape_ref)
-            expect(subject.members[:foo]).to be_kind_of(ShapeRef)
+            expect(subject.members[:foo]).to be_kind_of(MemberShape)
           end
         end
 
         describe '#member?' do
           it 'returns true if member exists' do
-            shape_ref = ShapeRef.new(shape: StringShape.new)
+            shape_ref = MemberShape.new(target: StringShape.new)
             subject.add_member(:foo, shape_ref)
             expect(subject.member?(:foo)).to be(true)
           end
@@ -419,9 +419,9 @@ module Shapes
 
         describe '#member' do
           it 'returns the member' do
-            shape_ref = ShapeRef.new(shape: StringShape.new)
+            shape_ref = MemberShape.new(target: StringShape.new)
             subject.add_member(:foo, shape_ref)
-            expect(subject.member(:foo)).to be_kind_of(ShapeRef)
+            expect(subject.member(:foo)).to be_kind_of(MemberShape)
           end
         end
       end
@@ -464,7 +464,7 @@ module Shapes
 
         describe '#add_member' do
           it 'adds a member with its type' do
-            shape_ref = ShapeRef.new(shape: StringShape.new)
+            shape_ref = MemberShape.new(target: StringShape.new)
             subject.add_member(:foo, union_type, shape_ref)
             expect(subject.members[:foo]).to be(shape_ref)
             expect(subject.member_types[:foo]).to be(union_type)
@@ -474,7 +474,7 @@ module Shapes
 
         describe '#member?' do
           it 'returns true if member exists' do
-            shape_ref = ShapeRef.new(shape: StringShape.new)
+            shape_ref = MemberShape.new(target: StringShape.new)
             subject.add_member(:foo, union_type, shape_ref)
             expect(subject.member?(:foo)).to be(true)
           end
@@ -482,15 +482,15 @@ module Shapes
 
         describe '#member' do
           it 'returns the member' do
-            shape_ref = ShapeRef.new(shape: StringShape.new)
+            shape_ref = MemberShape.new(target: StringShape.new)
             subject.add_member(:foo, union_type, shape_ref)
-            expect(subject.member(:foo)).to be_kind_of(ShapeRef)
+            expect(subject.member(:foo)).to be_kind_of(MemberShape)
           end
         end
 
         describe '#member_type?' do
           it 'returns true if member type exists' do
-            shape_ref = ShapeRef.new(shape: StringShape.new)
+            shape_ref = MemberShape.new(target: StringShape.new)
             subject.add_member(:foo, union_type, shape_ref)
             expect(subject.member_type?(:foo)).to be(true)
           end
@@ -498,7 +498,7 @@ module Shapes
 
         describe '#member_type' do
           it 'returns the member type' do
-            shape_ref = ShapeRef.new(shape: StringShape.new)
+            shape_ref = MemberShape.new(target: StringShape.new)
             subject.add_member(:foo, union_type, shape_ref)
             expect(subject.member_type(:foo)).to eq(union_type)
           end
@@ -506,7 +506,7 @@ module Shapes
 
         describe '#member_by_type?' do
           it 'returns true if member by type exists' do
-            shape_ref = ShapeRef.new(shape: StringShape.new)
+            shape_ref = MemberShape.new(target: StringShape.new)
             subject.add_member(:foo, union_type, shape_ref)
             expect(subject.member_by_type?(union_type)).to be(true)
           end
@@ -514,7 +514,7 @@ module Shapes
 
         describe '#member_by_type' do
           it 'returns the member by type' do
-            shape_ref = ShapeRef.new(shape: StringShape.new)
+            shape_ref = MemberShape.new(target: StringShape.new)
             subject.add_member(:foo, union_type, shape_ref)
             expect(subject.member_by_type(union_type)).to eq([:foo, shape_ref])
           end
diff --git a/gems/smithy-xml/lib/smithy-xml/builder.rb b/gems/smithy-xml/lib/smithy-xml/builder.rb
index 3ef193a17..c6935ad17 100644
--- a/gems/smithy-xml/lib/smithy-xml/builder.rb
+++ b/gems/smithy-xml/lib/smithy-xml/builder.rb
@@ -14,17 +14,17 @@ def initialize(options = {})
       end
 
       def build(shape, data, target = nil)
-        ref = shape.is_a?(ShapeRef) ? shape : ShapeRef.new(shape: shape)
+        ref = shape.is_a?(MemberShape) ? shape : MemberShape.new(target: shape)
         target ||= []
         @builder = DocBuilder.new(target: target, indent: @indent, pad: @pad)
-        structure(ref.location_name || ref.shape.traits['smithy.api#xmlName'] || ref.shape.name, ref, data)
+        structure(ref.location_name || ref.target.traits['smithy.api#xmlName'] || ref.target.name, ref, data)
         target.join
       end
 
       private
 
       def shape(name, ref, value)
-        case ref.shape
+        case ref.target
         when BlobShape then node(name, ref, blob(value))
         when ListShape then list(name, ref, value)
         when MapShape then map(name, ref, value)
@@ -40,7 +40,7 @@ def blob(value)
       end
 
       def list(name, ref, values)
-        member_ref = ref.shape.member
+        member_ref = ref.target.member
         if flat?(ref)
           values.each do |value|
             shape(name, member_ref, value)
@@ -48,15 +48,15 @@ def list(name, ref, values)
         else
           node(name, ref) do
             values.each do |value|
-              shape(location_name(member_ref, 'member'), ref.shape.member, value)
+              shape(location_name(member_ref, 'member'), ref.target.member, value)
             end
           end
         end
       end
 
       def map(name, ref, values) # rubocop:disable Metrics/AbcSize
-        key_ref = ref.shape.key
-        value_ref = ref.shape.value
+        key_ref = ref.target.key
+        value_ref = ref.target.value
         if flat?(ref)
           values.each do |key, value|
             node(name, ref) do
@@ -67,7 +67,7 @@ def map(name, ref, values) # rubocop:disable Metrics/AbcSize
         else
           node(name, ref) do
             values.each do |key, value|
-              node('entry', ShapeRef.new(shape: MapShape.new)) do
+              node('entry', MemberShape.new(target: MapShape.new)) do
                 shape(location_name(key_ref, 'key'), key_ref, key)
                 shape(location_name(value_ref, 'value'), value_ref, value)
               end
@@ -80,7 +80,7 @@ def structure(name, ref, values)
         return node(name, ref) if values.empty?
 
         node(name, ref, structure_attrs(ref, values)) do
-          ref.shape.members.each do |member_name, member_ref|
+          ref.target.members.each do |member_name, member_ref|
             next if values[member_name].nil?
             next if xml_attribute?(member_ref)
 
@@ -90,7 +90,7 @@ def structure(name, ref, values)
       end
 
       def structure_attrs(ref, values)
-        ref.shape.members.each_with_object({}) do |(member_name, member_ref), attrs|
+        ref.target.members.each_with_object({}) do |(member_name, member_ref), attrs|
           if xml_attribute?(member_ref) && values.key?(member_name)
             attrs[location_name(member_ref, member_ref.location_name)] = values[member_name]
           end
@@ -99,7 +99,7 @@ def structure_attrs(ref, values)
 
       def timestamp(ref, value)
         trait = 'smithy.api#timestampFormat'
-        case ref.traits[trait] || ref.shape.traits[trait]
+        case ref.traits[trait] || ref.target.traits[trait]
         when 'epoch-seconds' then value.to_i.to_s
         when 'http-date' then value.utc.httpdate
         else
@@ -113,12 +113,12 @@ def union(name, ref, values) # rubocop:disable Metrics/AbcSize
 
         node(name, ref, structure_attrs(ref, values)) do
           if values.is_a?(Schema::Union)
-            _name, member_ref = ref.shape.member_by_type(values.class)
+            _name, member_ref = ref.target.member_by_type(values.class)
             shape(location_name(member_ref, member_ref.location_name), member_ref, values.value)
           else
             key, value = values.first
-            if ref.shape.member?(key)
-              member_ref = ref.shape.member(key)
+            if ref.target.member?(key)
+              member_ref = ref.target.member(key)
               shape(location_name(member_ref, member_ref.location_name), member_ref, value)
             end
           end
@@ -156,7 +156,7 @@ def node(name, ref, *args, &)
 
       def shape_attrs(ref)
         trait = 'smithy.api#xmlNamespace'
-        xmlns = ref.traits[trait] || ref.shape.traits[trait]
+        xmlns = ref.traits[trait] || ref.target.traits[trait]
         return {} unless xmlns
 
         if (prefix = xmlns['prefix'])
diff --git a/gems/smithy-xml/lib/smithy-xml/codec.rb b/gems/smithy-xml/lib/smithy-xml/codec.rb
index 821199ba7..aede627ed 100644
--- a/gems/smithy-xml/lib/smithy-xml/codec.rb
+++ b/gems/smithy-xml/lib/smithy-xml/codec.rb
@@ -9,7 +9,7 @@ def initialize(options = {})
         @options = options
       end
 
-      # @param [ShapeRef, Shape] shape
+      # @param [MemberShape, Shape] shape
       # @param [Object] data
       # @param [String, nil] target (nil)
       # @return [String, nil]
@@ -17,7 +17,7 @@ def build(shape, data, target = nil)
         Builder.new(@options).build(shape, data, target)
       end
 
-      # @param [ShapeRef, Shape] shape
+      # @param [MemberShape, Shape] shape
       # @param [String] bytes
       # @param [Object, nil] target (nil)
       # @return [Object, nil]
diff --git a/gems/smithy-xml/lib/smithy-xml/parser.rb b/gems/smithy-xml/lib/smithy-xml/parser.rb
index 9f54726a4..a48ddbc8f 100644
--- a/gems/smithy-xml/lib/smithy-xml/parser.rb
+++ b/gems/smithy-xml/lib/smithy-xml/parser.rb
@@ -22,12 +22,12 @@ def initialize(options = {})
       # The purpose of the unhandled callback block is to allow callers to access values
       # such as a request ID that are part of the XML body but not part of modeling.
       #
-      # @param [ShapeRef, Shape] shape
+      # @param [MemberShape, Shape] shape
       # @param [String] bytes
       # @param [Object, nil] target (nil)
       # @return [Object]
       def parse(shape, bytes, target = nil, &)
-        ref = shape.is_a?(ShapeRef) ? shape : ShapeRef.new(shape: shape)
+        ref = shape.is_a?(MemberShape) ? shape : MemberShape.new(target: shape)
         bytes = '<xml/>' if bytes.nil? || bytes.empty?
         stack = Stack.new(ref, target, &)
         @engine.new(stack).parse(bytes.to_s)
diff --git a/gems/smithy-xml/lib/smithy-xml/parser/frame.rb b/gems/smithy-xml/lib/smithy-xml/parser/frame.rb
index 161464e49..da8d4dd18 100644
--- a/gems/smithy-xml/lib/smithy-xml/parser/frame.rb
+++ b/gems/smithy-xml/lib/smithy-xml/parser/frame.rb
@@ -25,7 +25,7 @@ def new(path, parent, ref, result = nil)
           private
 
           def frame_class(ref)
-            klass = FRAME_CLASSES[ref.shape.class]
+            klass = FRAME_CLASSES[ref.target.class]
             if klass == ListFrame && ref.traits.key?('smithy.api#xmlFlattened')
               FlatListFrame
             elsif klass == MapFrame && ref.traits.key?('smithy.api#xmlFlattened')
@@ -103,7 +103,7 @@ def result
       class FlatListFrame < Frame
         def initialize(xml_name, *args)
           super
-          @member = Frame.new(xml_name, self, @ref.shape.member)
+          @member = Frame.new(xml_name, self, @ref.target.member)
         end
 
         def result
@@ -147,7 +147,7 @@ class ListFrame < Frame
         def initialize(*args)
           super
           @result = []
-          @member_xml_name = @ref.shape.member.traits['smithy.api#xmlName'] || 'member'
+          @member_xml_name = @ref.target.member.traits['smithy.api#xmlName'] || 'member'
         end
 
         def child_frame(xml_name)
@@ -155,7 +155,7 @@ def child_frame(xml_name)
             raise NotImplementedError, "Expected XML name '#{@member_xml_name}' for ListFrame, got '#{xml_name}'"
           end
 
-          Frame.new(xml_name, self, @ref.shape.member)
+          Frame.new(xml_name, self, @ref.target.member)
         end
 
         def consume_child_frame(child)
@@ -167,10 +167,10 @@ def consume_child_frame(child)
       class MapEntryFrame < Frame
         def initialize(xml_name, *args)
           super
-          @key_name = @ref.shape.key.traits['smithy.api#xmlName'] || 'key'
-          @key = Frame.new(xml_name, self, @ref.shape.key)
-          @value_name = @ref.shape.value.traits['smithy.api#xmlName'] || 'value'
-          @value = Frame.new(xml_name, self, @ref.shape.value)
+          @key_name = @ref.target.key.traits['smithy.api#xmlName'] || 'key'
+          @key = Frame.new(xml_name, self, @ref.target.key)
+          @value_name = @ref.target.value.traits['smithy.api#xmlName'] || 'value'
+          @value = Frame.new(xml_name, self, @ref.target.value)
         end
 
         # @return [StringFrame]
@@ -234,16 +234,16 @@ class StructureFrame < Frame
         def initialize(xml_name, parent, ref, result = nil)
           super
           @members = {}
-          ref.shape.members.each do |member_name, member_ref|
+          ref.target.members.each do |member_name, member_ref|
             @members[xml_name(member_ref)] = { name: member_name, ref: member_ref }
           end
-          @result ||= ref.shape.type.new
+          @result ||= ref.target.type.new
         end
 
         def child_frame(xml_name)
           if (@member = @members[xml_name])
             Frame.new(xml_name, self, @member[:ref])
-          elsif @ref.shape.is_a?(UnionShape)
+          elsif @ref.target.is_a?(UnionShape)
             UnknownMemberFrame.new(xml_name, self, nil, @result)
           else
             NullFrame.new(xml_name, self)
diff --git a/gems/smithy-xml/sig/smithy-xml/codec.rbs b/gems/smithy-xml/sig/smithy-xml/codec.rbs
index 43bbbff0b..5768e40d6 100644
--- a/gems/smithy-xml/sig/smithy-xml/codec.rbs
+++ b/gems/smithy-xml/sig/smithy-xml/codec.rbs
@@ -1,8 +1,8 @@
 module Smithy
   module Xml
     class Codec
-      def build: (Schema::Shapes::Shape | Schema::Shapes::ShapeRef shape, Object data) -> (nil | String)
-      def parse: (Schema::Shapes::Shape | Schema::Shapes::ShapeRef shape, String bytes, ?Object ?target) -> Object?
+      def build: (Schema::Shapes::Shape | Schema::Shapes::MemberShape shape, Object data) -> (nil | String)
+      def parse: (Schema::Shapes::Shape | Schema::Shapes::MemberShape shape, String bytes, ?Object ?target) -> Object?
     end
   end
 end
\ No newline at end of file
diff --git a/gems/smithy-xml/spec/smithy-xml/builder_spec.rb b/gems/smithy-xml/spec/smithy-xml/builder_spec.rb
index ff78c8bdd..bcbec1641 100644
--- a/gems/smithy-xml/spec/smithy-xml/builder_spec.rb
+++ b/gems/smithy-xml/spec/smithy-xml/builder_spec.rb
@@ -16,7 +16,7 @@ def inline(xml)
       end
 
       it 'returns an empty frame when given a unit shape' do
-        ref = Schema::Shapes::ShapeRef.new(shape: Schema::Shapes::Prelude::Unit)
+        ref = Schema::Shapes::MemberShape.new(target: Schema::Shapes::Prelude::Unit)
         expect(subject.build(ref, '')).to eq('<Unit/>')
       end
 
@@ -166,7 +166,7 @@ def inline(xml)
 
       context 'unions' do
         it 'builds unions as a type' do
-          union = structure_shape.member(:union).shape.member_type(:string).new(string: 'string')
+          union = structure_shape.member(:union).target.member_type(:string).new(string: 'string')
           type = structure_shape.type.new(union: union)
           bytes = subject.build(structure_shape, type)
           expect(bytes).to include('<union><string>string</string></union>')
@@ -179,7 +179,7 @@ def inline(xml)
         end
 
         it 'builds union unit members as a type' do
-          union = structure_shape.member(:union).shape.member_type(:unit).new(unit: Schema::EmptyStructure.new)
+          union = structure_shape.member(:union).target.member_type(:unit).new(unit: Schema::EmptyStructure.new)
           type = structure_shape.type.new(union: union)
           bytes = subject.build(structure_shape, type)
           expect(bytes).to include('<union><unit/></union>')
diff --git a/gems/smithy/lib/smithy/templates/client/errors_rbs.erb b/gems/smithy/lib/smithy/templates/client/errors_rbs.erb
index 002ea6564..fa54effba 100644
--- a/gems/smithy/lib/smithy/templates/client/errors_rbs.erb
+++ b/gems/smithy/lib/smithy/templates/client/errors_rbs.erb
@@ -3,7 +3,7 @@ module <%= module_name %>
 <% errors.each do |error| -%>
     class <%= error.name %> < Smithy::Client::ServiceError
 <% error.members.each do |member| -%>
-      def <%= member.name %>: () -> <%= Model::RBS.type(model, member.shape['target'], Model.shape(model, member.shape['target'])) %>?
+      def <%= member.name %>: () -> <%= Model::RBS.type(model, member.target['target'], Model.shape(model, member.target['target'])) %>?
 <% end -%>
 <% if error.retryable? -%>
       def retryable?: () -> true
diff --git a/gems/smithy/lib/smithy/templates/client/schema.erb b/gems/smithy/lib/smithy/templates/client/schema.erb
index 0a3afda6c..b4f51b6a0 100644
--- a/gems/smithy/lib/smithy/templates/client/schema.erb
+++ b/gems/smithy/lib/smithy/templates/client/schema.erb
@@ -34,7 +34,7 @@ module <%= module_name %>
 <% shape.members.each do |member| -%>
     <%= shape.name %>.add_member(:<%= member.name %>, <%= shape.union_type(member) %>, <%= member.initializer %>)
 <% end -%>
-    <%= shape.name %>.add_member(:unknown, Types::<%= shape.name %>::Unknown, ::Smithy::Schema::Shapes::ShapeRef.new(shape: ::Smithy::Schema::Shapes::Prelude::Unit))
+    <%= shape.name %>.add_member(:unknown, Types::<%= shape.name %>::Unknown, ::Smithy::Schema::Shapes::MemberShape.new(target: ::Smithy::Schema::Shapes::Prelude::Unit))
     <%= shape.name %>.type = <%= shape.type_class %>
 <% end -%>
 <% end -%>
diff --git a/gems/smithy/lib/smithy/views/client/schema.rb b/gems/smithy/lib/smithy/views/client/schema.rb
index 6df4f9b95..36f44b20f 100644
--- a/gems/smithy/lib/smithy/views/client/schema.rb
+++ b/gems/smithy/lib/smithy/views/client/schema.rb
@@ -115,16 +115,16 @@ def paginator
           private
 
           def build_input(input)
-            ShapeRef.new(@service, nil, input)
+            MemberShape.new(@service, nil, input)
           end
 
           def build_output(output)
-            ShapeRef.new(@service, nil, output)
+            MemberShape.new(@service, nil, output)
           end
 
           def build_errors(errors)
             errors = Set.new(@service.fetch('errors', [])).merge(errors)
-            errors.map { |error| ShapeRef.new(@service, nil, error) }
+            errors.map { |error| MemberShape.new(@service, nil, error) }
           end
         end
 
@@ -205,7 +205,7 @@ def http_payload
           private
 
           def build_shape_refs(members)
-            members.map { |name, member| ShapeRef.new(@service, name, member) }
+            members.map { |name, member| MemberShape.new(@service, name, member) }
           end
         end
 
@@ -221,7 +221,7 @@ def initialize(service, id, shape)
           private
 
           def build_shape_refs(members)
-            members.map { |name, shape_ref| ShapeRef.new(@service, name, shape_ref) }
+            members.map { |name, shape_ref| MemberShape.new(@service, name, shape_ref) }
           end
         end
 
@@ -237,7 +237,7 @@ def initialize(service, id, shape)
           private
 
           def build_shape_refs(members)
-            members.map { |name, member| ShapeRef.new(@service, name, member) }
+            members.map { |name, member| MemberShape.new(@service, name, member) }
           end
         end
 
@@ -245,7 +245,7 @@ def build_shape_refs(members)
         class ListShape < Shape
           def initialize(service, id, shape)
             super
-            @member = ShapeRef.new(@service, nil, shape['member'])
+            @member = MemberShape.new(@service, nil, shape['member'])
           end
 
           attr_reader :member
@@ -255,8 +255,8 @@ def initialize(service, id, shape)
         class MapShape < Shape
           def initialize(service, id, shape)
             super
-            @key = ShapeRef.new(@service, nil, shape['key'])
-            @value = ShapeRef.new(@service, nil, shape['value'])
+            @key = MemberShape.new(@service, nil, shape['key'])
+            @value = MemberShape.new(@service, nil, shape['value'])
           end
 
           attr_reader :key, :value
@@ -282,12 +282,12 @@ def union_type(shape_ref)
           private
 
           def build_shape_refs(members)
-            members.map { |name, member| ShapeRef.new(@service, name, member) }
+            members.map { |name, member| MemberShape.new(@service, name, member) }
           end
         end
 
         # @api private
-        class ShapeRef
+        class MemberShape
           OMITTED_TRAITS = %w[
             smithy.api#documentation
           ].freeze
@@ -320,17 +320,17 @@ def initialize(service, location_name, shape_ref)
             @service = service
             @name = location_name.underscore if location_name
             @location_name = location_name
-            @shape = shape(shape_ref['target'])
+            @target = shape(shape_ref['target'])
             @traits = shape_ref.fetch('traits', {}).except(*OMITTED_TRAITS)
           end
 
           attr_reader :name, :location_name
 
           def initializer
-            options_str = "shape: #{@shape}"
+            options_str = "target: #{@target}"
             options_str += ", location_name: \"#{@location_name}\"" if @location_name
             options_str += ", traits: #{@traits}" unless @traits.empty?
-            "::Smithy::Schema::Shapes::ShapeRef.new(#{options_str})"
+            "::Smithy::Schema::Shapes::MemberShape.new(#{options_str})"
           end
 
           def shape(id)
diff --git a/gems/smithy/spec/interfaces/rename_shapes_spec.rb b/gems/smithy/spec/interfaces/rename_shapes_spec.rb
index ae32e1bb7..a52bea17c 100644
--- a/gems/smithy/spec/interfaces/rename_shapes_spec.rb
+++ b/gems/smithy/spec/interfaces/rename_shapes_spec.rb
@@ -37,8 +37,8 @@
       it 'assigns renamed shapes to operation inputs and outputs' do
         client = RenameShapes::Client.new
         operation = client.config.service.operation(:operation)
-        expect(operation.input.shape.type).to eq(RenameShapes::Types::RenamedOperationInput)
-        expect(operation.output.shape.type).to eq(RenameShapes::Types::RenamedOperationOutput)
+        expect(operation.input.target.type).to eq(RenameShapes::Types::RenamedOperationInput)
+        expect(operation.output.target.type).to eq(RenameShapes::Types::RenamedOperationOutput)
       end
     end
   end
diff --git a/gems/smithy/spec/interfaces/synthetic_input_output_spec.rb b/gems/smithy/spec/interfaces/synthetic_input_output_spec.rb
index 9e7886cb1..b7de49521 100644
--- a/gems/smithy/spec/interfaces/synthetic_input_output_spec.rb
+++ b/gems/smithy/spec/interfaces/synthetic_input_output_spec.rb
@@ -37,25 +37,25 @@
       it 'assigns synthetic input and output shapes to the operation' do
         client = SyntheticInputOutput::Client.new
         operation = client.config.service.operation(:operation)
-        expect(operation.input.shape.type).to eq(SyntheticInputOutput::Types::OperationInput)
-        expect(operation.output.shape.type).to eq(SyntheticInputOutput::Types::OperationOutput)
+        expect(operation.input.target.type).to eq(SyntheticInputOutput::Types::OperationInput)
+        expect(operation.output.target.type).to eq(SyntheticInputOutput::Types::OperationOutput)
       end
 
       it 'preserves input and output shapes on the operation with the input and output trait' do
         client = SyntheticInputOutput::Client.new
         operation = client.config.service.operation(:operation_with_input_and_output_traits)
-        expect(operation.input.shape.type)
+        expect(operation.input.target.type)
           .to eq(SyntheticInputOutput::Types::OperationWithInputAndOutputTraitsInput)
-        expect(operation.output.shape.type)
+        expect(operation.output.target.type)
           .to eq(SyntheticInputOutput::Types::OperationWithInputAndOutputTraitsOutput)
       end
 
       it 'handles naming conflicts by inserting Operation between the operation name and the suffix' do
         client = SyntheticInputOutput::Client.new
         operation = client.config.service.operation(:operation_with_naming_conflict)
-        expect(operation.input.shape.type)
+        expect(operation.input.target.type)
           .to eq(SyntheticInputOutput::Types::OperationWithNamingConflictOperationInput)
-        expect(operation.output.shape.type)
+        expect(operation.output.target.type)
           .to eq(SyntheticInputOutput::Types::OperationWithNamingConflictOperationOutput)
       end
     end
diff --git a/gems/smithy/spec/support/examples/schema_examples.rb b/gems/smithy/spec/support/examples/schema_examples.rb
index 58cbd0f9d..68e320ac4 100644
--- a/gems/smithy/spec/support/examples/schema_examples.rb
+++ b/gems/smithy/spec/support/examples/schema_examples.rb
@@ -190,9 +190,9 @@ def expect_generated_shape(subject, shape_class, shape_hash)
 
       it 'has members' do
         expect(subject.members.keys).to eq(%i[foo])
-        expect(subject.members[:foo].shape).to be_a(Smithy::Schema::Shapes::StructureShape)
+        expect(subject.members[:foo].target).to be_a(Smithy::Schema::Shapes::StructureShape)
         expect(subject.members[:foo].traits).to eq(expected_member['traits'])
-        expect(subject.members[:foo].shape.id).to eq(expected_member['target'])
+        expect(subject.members[:foo].target.id).to eq(expected_member['target'])
       end
 
       it 'has a member with traits' do
@@ -217,9 +217,9 @@ def expect_generated_shape(subject, shape_class, shape_hash)
 
       it 'has members' do
         expect(subject.members.keys).to eq(%i[baz])
-        expect(subject.members[:baz].shape).to be_a(Smithy::Schema::Shapes::StructureShape)
+        expect(subject.members[:baz].target).to be_a(Smithy::Schema::Shapes::StructureShape)
         expect(subject.members[:baz].traits).to eq(expected_member['traits'])
-        expect(subject.members[:baz].shape.id).to eq(expected_member['target'])
+        expect(subject.members[:baz].target.id).to eq(expected_member['target'])
       end
 
       it 'has a member with traits' do
@@ -243,8 +243,8 @@ def expect_generated_shape(subject, shape_class, shape_hash)
       end
 
       it 'has a member' do
-        expect(subject.member.shape).to be_a(Smithy::Schema::Shapes::StringShape)
-        expect(subject.member.shape.id).to eq(expected_member['target'])
+        expect(subject.member.target).to be_a(Smithy::Schema::Shapes::StringShape)
+        expect(subject.member.target.id).to eq(expected_member['target'])
       end
 
       it 'has a member with traits' do
@@ -268,10 +268,10 @@ def expect_generated_shape(subject, shape_class, shape_hash)
       end
 
       it 'has key and value members' do
-        expect(subject.key.shape).to be_a(Smithy::Schema::Shapes::StringShape)
-        expect(subject.key.shape.id).to eq(expected_shape['key']['target'])
-        expect(subject.value.shape).to be_a(Smithy::Schema::Shapes::StringShape)
-        expect(subject.value.shape.id).to eq(expected_shape['value']['target'])
+        expect(subject.key.target).to be_a(Smithy::Schema::Shapes::StringShape)
+        expect(subject.key.target.id).to eq(expected_shape['key']['target'])
+        expect(subject.value.target).to be_a(Smithy::Schema::Shapes::StringShape)
+        expect(subject.value.target.id).to eq(expected_shape['value']['target'])
       end
 
       it 'has keys and values with traits' do
@@ -315,12 +315,12 @@ def expect_generated_shape(subject, shape_class, shape_hash)
       end
 
       it 'supports unit types' do
-        expect(subject.member(:unit).shape).to eq(Smithy::Schema::Shapes::Prelude::Unit)
+        expect(subject.member(:unit).target).to eq(Smithy::Schema::Shapes::Prelude::Unit)
         expect(subject.member_type(:unit)).to eq(ShapeService::Types::Union::Unit)
       end
 
       it 'has an unknown member' do
-        expect(subject.member(:unknown).shape).to eq(Smithy::Schema::Shapes::Prelude::Unit)
+        expect(subject.member(:unknown).target).to eq(Smithy::Schema::Shapes::Prelude::Unit)
         expect(subject.member_type(:unknown)).to eq(ShapeService::Types::Union::Unknown)
       end
     end

From c16b2c2641034d2497aadb7e64beb462848a5d4b Mon Sep 17 00:00:00 2001
From: Juli Tera <terajul@amazon.com>
Date: Wed, 3 Jun 2026 17:20:22 -0700
Subject: [PATCH 02/23] Fix unintended rename in errors

---
 gems/smithy/lib/smithy/templates/client/errors_rbs.erb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gems/smithy/lib/smithy/templates/client/errors_rbs.erb b/gems/smithy/lib/smithy/templates/client/errors_rbs.erb
index fa54effba..002ea6564 100644
--- a/gems/smithy/lib/smithy/templates/client/errors_rbs.erb
+++ b/gems/smithy/lib/smithy/templates/client/errors_rbs.erb
@@ -3,7 +3,7 @@ module <%= module_name %>
 <% errors.each do |error| -%>
     class <%= error.name %> < Smithy::Client::ServiceError
 <% error.members.each do |member| -%>
-      def <%= member.name %>: () -> <%= Model::RBS.type(model, member.target['target'], Model.shape(model, member.target['target'])) %>?
+      def <%= member.name %>: () -> <%= Model::RBS.type(model, member.shape['target'], Model.shape(model, member.shape['target'])) %>?
 <% end -%>
 <% if error.retryable? -%>
       def retryable?: () -> true

From acd5268e21d5f7a6f34c1499c7ff5d5007b591da Mon Sep 17 00:00:00 2001
From: Juli Tera <terajul@amazon.com>
Date: Wed, 3 Jun 2026 17:24:35 -0700
Subject: [PATCH 03/23] Introduce target reference

---
 gems/smithy-schema/lib/smithy-schema/shapes.rb | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/gems/smithy-schema/lib/smithy-schema/shapes.rb b/gems/smithy-schema/lib/smithy-schema/shapes.rb
index d78c517dc..5431260f3 100644
--- a/gems/smithy-schema/lib/smithy-schema/shapes.rb
+++ b/gems/smithy-schema/lib/smithy-schema/shapes.rb
@@ -11,8 +11,11 @@ def initialize(options = {})
           @name = options[:name]
           @traits = options[:traits] || {}
           @metadata = {}
+          @target = self
         end
 
+        attr_reader :target
+
         # @return [String] Absolute shape ID from model
         attr_accessor :id
 

From 20ed88599849c3ab61a9a24aff99e3e93ab810ed Mon Sep 17 00:00:00 2001
From: Juli Tera <terajul@amazon.com>
Date: Wed, 3 Jun 2026 17:24:51 -0700
Subject: [PATCH 04/23] Update projections

---
 projections/shapes/lib/shapes/client.rb   |   2 +
 projections/shapes/lib/shapes/schema.rb   | 100 +++++++++++-----------
 projections/weather/lib/weather/client.rb |   2 +
 projections/weather/lib/weather/schema.rb |  50 +++++------
 4 files changed, 79 insertions(+), 75 deletions(-)

diff --git a/projections/shapes/lib/shapes/client.rb b/projections/shapes/lib/shapes/client.rb
index 43823faab..34b0ad788 100644
--- a/projections/shapes/lib/shapes/client.rb
+++ b/projections/shapes/lib/shapes/client.rb
@@ -20,6 +20,7 @@
 require 'smithy-client/plugins/retry_errors'
 require 'smithy-client/plugins/sign_requests'
 require 'smithy-client/plugins/stub_responses'
+require 'smithy-client/plugins/transfer_encoding'
 require 'smithy-client/plugins/user_agent'
 
 module ShapeService
@@ -49,6 +50,7 @@ class Client < Smithy::Client::Base
     add_plugin(Smithy::Client::Plugins::RetryErrors)
     add_plugin(Smithy::Client::Plugins::SignRequests)
     add_plugin(Smithy::Client::Plugins::StubResponses)
+    add_plugin(Smithy::Client::Plugins::TransferEncoding)
     add_plugin(Smithy::Client::Plugins::UserAgent)
 
     # @param options [Hash] Client options
diff --git a/projections/shapes/lib/shapes/schema.rb b/projections/shapes/lib/shapes/schema.rb
index 40e8988f8..61a8da789 100644
--- a/projections/shapes/lib/shapes/schema.rb
+++ b/projections/shapes/lib/shapes/schema.rb
@@ -28,57 +28,57 @@ module Schema
     Timestamp = ::Smithy::Schema::Shapes::TimestampShape.new(id: "smithy.ruby.tests#Timestamp", name: "Timestamp", traits: {"smithy.ruby.tests#shape" => {}})
     Union = ::Smithy::Schema::Shapes::UnionShape.new(id: "smithy.ruby.tests#Union", name: "Union", traits: {"smithy.ruby.tests#shape" => {}})
 
-    Enum.add_member(:foo, ::Smithy::Schema::Shapes::ShapeRef.new(shape: ::Smithy::Schema::Shapes::Prelude::Unit, location_name: "FOO", traits: {"smithy.api#enumValue" => "bar"}))
-    IntEnum.add_member(:baz, ::Smithy::Schema::Shapes::ShapeRef.new(shape: ::Smithy::Schema::Shapes::Prelude::Unit, location_name: "BAZ", traits: {"smithy.api#enumValue" => 1}))
-    List.member = ::Smithy::Schema::Shapes::ShapeRef.new(shape: String, traits: {"smithy.ruby.tests#shape" => {}})
-    Map.key = ::Smithy::Schema::Shapes::ShapeRef.new(shape: String, traits: {"smithy.ruby.tests#shape" => {}})
-    Map.value = ::Smithy::Schema::Shapes::ShapeRef.new(shape: String, traits: {"smithy.ruby.tests#shape" => {}})
-    OperationInput.add_member(:blob, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Blob, location_name: "blob"))
-    OperationInput.add_member(:boolean, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Boolean, location_name: "boolean"))
-    OperationInput.add_member(:string, ::Smithy::Schema::Shapes::ShapeRef.new(shape: String, location_name: "string"))
-    OperationInput.add_member(:byte, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Byte, location_name: "byte"))
-    OperationInput.add_member(:short, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Short, location_name: "short"))
-    OperationInput.add_member(:integer, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Integer, location_name: "integer"))
-    OperationInput.add_member(:long, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Long, location_name: "long"))
-    OperationInput.add_member(:float, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Float, location_name: "float"))
-    OperationInput.add_member(:double, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Double, location_name: "double"))
-    OperationInput.add_member(:big_integer, ::Smithy::Schema::Shapes::ShapeRef.new(shape: BigInteger, location_name: "bigInteger"))
-    OperationInput.add_member(:big_decimal, ::Smithy::Schema::Shapes::ShapeRef.new(shape: BigDecimal, location_name: "bigDecimal"))
-    OperationInput.add_member(:timestamp, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Timestamp, location_name: "timestamp"))
-    OperationInput.add_member(:document, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Document, location_name: "document"))
-    OperationInput.add_member(:enum, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Enum, location_name: "enum"))
-    OperationInput.add_member(:int_enum, ::Smithy::Schema::Shapes::ShapeRef.new(shape: IntEnum, location_name: "intEnum"))
-    OperationInput.add_member(:list, ::Smithy::Schema::Shapes::ShapeRef.new(shape: List, location_name: "list"))
-    OperationInput.add_member(:map, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Map, location_name: "map"))
-    OperationInput.add_member(:structure, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Structure, location_name: "structure"))
-    OperationInput.add_member(:union, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Union, location_name: "union"))
+    Enum.add_member(:foo, ::Smithy::Schema::Shapes::MemberShape.new(target: ::Smithy::Schema::Shapes::Prelude::Unit, location_name: "FOO", traits: {"smithy.api#enumValue" => "bar"}))
+    IntEnum.add_member(:baz, ::Smithy::Schema::Shapes::MemberShape.new(target: ::Smithy::Schema::Shapes::Prelude::Unit, location_name: "BAZ", traits: {"smithy.api#enumValue" => 1}))
+    List.member = ::Smithy::Schema::Shapes::MemberShape.new(target: String, traits: {"smithy.ruby.tests#shape" => {}})
+    Map.key = ::Smithy::Schema::Shapes::MemberShape.new(target: String, traits: {"smithy.ruby.tests#shape" => {}})
+    Map.value = ::Smithy::Schema::Shapes::MemberShape.new(target: String, traits: {"smithy.ruby.tests#shape" => {}})
+    OperationInput.add_member(:blob, ::Smithy::Schema::Shapes::MemberShape.new(target: Blob, location_name: "blob"))
+    OperationInput.add_member(:boolean, ::Smithy::Schema::Shapes::MemberShape.new(target: Boolean, location_name: "boolean"))
+    OperationInput.add_member(:string, ::Smithy::Schema::Shapes::MemberShape.new(target: String, location_name: "string"))
+    OperationInput.add_member(:byte, ::Smithy::Schema::Shapes::MemberShape.new(target: Byte, location_name: "byte"))
+    OperationInput.add_member(:short, ::Smithy::Schema::Shapes::MemberShape.new(target: Short, location_name: "short"))
+    OperationInput.add_member(:integer, ::Smithy::Schema::Shapes::MemberShape.new(target: Integer, location_name: "integer"))
+    OperationInput.add_member(:long, ::Smithy::Schema::Shapes::MemberShape.new(target: Long, location_name: "long"))
+    OperationInput.add_member(:float, ::Smithy::Schema::Shapes::MemberShape.new(target: Float, location_name: "float"))
+    OperationInput.add_member(:double, ::Smithy::Schema::Shapes::MemberShape.new(target: Double, location_name: "double"))
+    OperationInput.add_member(:big_integer, ::Smithy::Schema::Shapes::MemberShape.new(target: BigInteger, location_name: "bigInteger"))
+    OperationInput.add_member(:big_decimal, ::Smithy::Schema::Shapes::MemberShape.new(target: BigDecimal, location_name: "bigDecimal"))
+    OperationInput.add_member(:timestamp, ::Smithy::Schema::Shapes::MemberShape.new(target: Timestamp, location_name: "timestamp"))
+    OperationInput.add_member(:document, ::Smithy::Schema::Shapes::MemberShape.new(target: Document, location_name: "document"))
+    OperationInput.add_member(:enum, ::Smithy::Schema::Shapes::MemberShape.new(target: Enum, location_name: "enum"))
+    OperationInput.add_member(:int_enum, ::Smithy::Schema::Shapes::MemberShape.new(target: IntEnum, location_name: "intEnum"))
+    OperationInput.add_member(:list, ::Smithy::Schema::Shapes::MemberShape.new(target: List, location_name: "list"))
+    OperationInput.add_member(:map, ::Smithy::Schema::Shapes::MemberShape.new(target: Map, location_name: "map"))
+    OperationInput.add_member(:structure, ::Smithy::Schema::Shapes::MemberShape.new(target: Structure, location_name: "structure"))
+    OperationInput.add_member(:union, ::Smithy::Schema::Shapes::MemberShape.new(target: Union, location_name: "union"))
     OperationInput.type = Types::OperationInput
-    OperationOutput.add_member(:blob, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Blob, location_name: "blob"))
-    OperationOutput.add_member(:boolean, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Boolean, location_name: "boolean"))
-    OperationOutput.add_member(:string, ::Smithy::Schema::Shapes::ShapeRef.new(shape: String, location_name: "string"))
-    OperationOutput.add_member(:byte, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Byte, location_name: "byte"))
-    OperationOutput.add_member(:short, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Short, location_name: "short"))
-    OperationOutput.add_member(:integer, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Integer, location_name: "integer"))
-    OperationOutput.add_member(:long, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Long, location_name: "long"))
-    OperationOutput.add_member(:float, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Float, location_name: "float"))
-    OperationOutput.add_member(:double, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Double, location_name: "double"))
-    OperationOutput.add_member(:big_integer, ::Smithy::Schema::Shapes::ShapeRef.new(shape: BigInteger, location_name: "bigInteger"))
-    OperationOutput.add_member(:big_decimal, ::Smithy::Schema::Shapes::ShapeRef.new(shape: BigDecimal, location_name: "bigDecimal"))
-    OperationOutput.add_member(:timestamp, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Timestamp, location_name: "timestamp"))
-    OperationOutput.add_member(:document, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Document, location_name: "document"))
-    OperationOutput.add_member(:enum, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Enum, location_name: "enum"))
-    OperationOutput.add_member(:int_enum, ::Smithy::Schema::Shapes::ShapeRef.new(shape: IntEnum, location_name: "intEnum"))
-    OperationOutput.add_member(:list, ::Smithy::Schema::Shapes::ShapeRef.new(shape: List, location_name: "list"))
-    OperationOutput.add_member(:map, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Map, location_name: "map"))
-    OperationOutput.add_member(:structure, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Structure, location_name: "structure"))
-    OperationOutput.add_member(:union, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Union, location_name: "union"))
+    OperationOutput.add_member(:blob, ::Smithy::Schema::Shapes::MemberShape.new(target: Blob, location_name: "blob"))
+    OperationOutput.add_member(:boolean, ::Smithy::Schema::Shapes::MemberShape.new(target: Boolean, location_name: "boolean"))
+    OperationOutput.add_member(:string, ::Smithy::Schema::Shapes::MemberShape.new(target: String, location_name: "string"))
+    OperationOutput.add_member(:byte, ::Smithy::Schema::Shapes::MemberShape.new(target: Byte, location_name: "byte"))
+    OperationOutput.add_member(:short, ::Smithy::Schema::Shapes::MemberShape.new(target: Short, location_name: "short"))
+    OperationOutput.add_member(:integer, ::Smithy::Schema::Shapes::MemberShape.new(target: Integer, location_name: "integer"))
+    OperationOutput.add_member(:long, ::Smithy::Schema::Shapes::MemberShape.new(target: Long, location_name: "long"))
+    OperationOutput.add_member(:float, ::Smithy::Schema::Shapes::MemberShape.new(target: Float, location_name: "float"))
+    OperationOutput.add_member(:double, ::Smithy::Schema::Shapes::MemberShape.new(target: Double, location_name: "double"))
+    OperationOutput.add_member(:big_integer, ::Smithy::Schema::Shapes::MemberShape.new(target: BigInteger, location_name: "bigInteger"))
+    OperationOutput.add_member(:big_decimal, ::Smithy::Schema::Shapes::MemberShape.new(target: BigDecimal, location_name: "bigDecimal"))
+    OperationOutput.add_member(:timestamp, ::Smithy::Schema::Shapes::MemberShape.new(target: Timestamp, location_name: "timestamp"))
+    OperationOutput.add_member(:document, ::Smithy::Schema::Shapes::MemberShape.new(target: Document, location_name: "document"))
+    OperationOutput.add_member(:enum, ::Smithy::Schema::Shapes::MemberShape.new(target: Enum, location_name: "enum"))
+    OperationOutput.add_member(:int_enum, ::Smithy::Schema::Shapes::MemberShape.new(target: IntEnum, location_name: "intEnum"))
+    OperationOutput.add_member(:list, ::Smithy::Schema::Shapes::MemberShape.new(target: List, location_name: "list"))
+    OperationOutput.add_member(:map, ::Smithy::Schema::Shapes::MemberShape.new(target: Map, location_name: "map"))
+    OperationOutput.add_member(:structure, ::Smithy::Schema::Shapes::MemberShape.new(target: Structure, location_name: "structure"))
+    OperationOutput.add_member(:union, ::Smithy::Schema::Shapes::MemberShape.new(target: Union, location_name: "union"))
     OperationOutput.type = Types::OperationOutput
-    Structure.add_member(:member, ::Smithy::Schema::Shapes::ShapeRef.new(shape: String, location_name: "member", traits: {"smithy.ruby.tests#shape" => {}}))
+    Structure.add_member(:member, ::Smithy::Schema::Shapes::MemberShape.new(target: String, location_name: "member", traits: {"smithy.ruby.tests#shape" => {}}))
     Structure.type = Types::Structure
-    Union.add_member(:string, Types::Union::String, ::Smithy::Schema::Shapes::ShapeRef.new(shape: String, location_name: "string", traits: {"smithy.ruby.tests#shape" => {}}))
-    Union.add_member(:structure, Types::Union::Structure, ::Smithy::Schema::Shapes::ShapeRef.new(shape: Structure, location_name: "structure", traits: {"smithy.ruby.tests#shape" => {}}))
-    Union.add_member(:unit, Types::Union::Unit, ::Smithy::Schema::Shapes::ShapeRef.new(shape: ::Smithy::Schema::Shapes::Prelude::Unit, location_name: "unit", traits: {"smithy.ruby.tests#shape" => {}}))
-    Union.add_member(:unknown, Types::Union::Unknown, ::Smithy::Schema::Shapes::ShapeRef.new(shape: ::Smithy::Schema::Shapes::Prelude::Unit))
+    Union.add_member(:string, Types::Union::String, ::Smithy::Schema::Shapes::MemberShape.new(target: String, location_name: "string", traits: {"smithy.ruby.tests#shape" => {}}))
+    Union.add_member(:structure, Types::Union::Structure, ::Smithy::Schema::Shapes::MemberShape.new(target: Structure, location_name: "structure", traits: {"smithy.ruby.tests#shape" => {}}))
+    Union.add_member(:unit, Types::Union::Unit, ::Smithy::Schema::Shapes::MemberShape.new(target: ::Smithy::Schema::Shapes::Prelude::Unit, location_name: "unit", traits: {"smithy.ruby.tests#shape" => {}}))
+    Union.add_member(:unknown, Types::Union::Unknown, ::Smithy::Schema::Shapes::MemberShape.new(target: ::Smithy::Schema::Shapes::Prelude::Unit))
     Union.type = Types::Union
 
     ShapeService = ::Smithy::Schema::Shapes::ServiceShape.new do |service|
@@ -89,8 +89,8 @@ module Schema
       service.add_operation(:operation, ::Smithy::Schema::Shapes::OperationShape.new do |operation|
         operation.id = "smithy.ruby.tests#Operation"
         operation.name = "Operation"
-        operation.input = ::Smithy::Schema::Shapes::ShapeRef.new(shape: OperationInput)
-        operation.output = ::Smithy::Schema::Shapes::ShapeRef.new(shape: OperationOutput)
+        operation.input = ::Smithy::Schema::Shapes::MemberShape.new(target: OperationInput)
+        operation.output = ::Smithy::Schema::Shapes::MemberShape.new(target: OperationOutput)
         operation.traits = {"smithy.ruby.tests#shape" => {}}
       end)
     end
diff --git a/projections/weather/lib/weather/client.rb b/projections/weather/lib/weather/client.rb
index 80efaf90b..c4e47eb3b 100644
--- a/projections/weather/lib/weather/client.rb
+++ b/projections/weather/lib/weather/client.rb
@@ -20,6 +20,7 @@
 require 'smithy-client/plugins/retry_errors'
 require 'smithy-client/plugins/sign_requests'
 require 'smithy-client/plugins/stub_responses'
+require 'smithy-client/plugins/transfer_encoding'
 require 'smithy-client/plugins/user_agent'
 
 module Weather
@@ -49,6 +50,7 @@ class Client < Smithy::Client::Base
     add_plugin(Smithy::Client::Plugins::RetryErrors)
     add_plugin(Smithy::Client::Plugins::SignRequests)
     add_plugin(Smithy::Client::Plugins::StubResponses)
+    add_plugin(Smithy::Client::Plugins::TransferEncoding)
     add_plugin(Smithy::Client::Plugins::UserAgent)
 
     # @param options [Hash] Client options
diff --git a/projections/weather/lib/weather/schema.rb b/projections/weather/lib/weather/schema.rb
index ddcc30a94..a63e42308 100644
--- a/projections/weather/lib/weather/schema.rb
+++ b/projections/weather/lib/weather/schema.rb
@@ -19,31 +19,31 @@ module Schema
     ListCitiesOutput = ::Smithy::Schema::Shapes::StructureShape.new(id: "example.weather#ListCitiesOutput", name: "ListCitiesOutput")
     NoSuchResource = ::Smithy::Schema::Shapes::StructureShape.new(id: "example.weather#NoSuchResource", name: "NoSuchResource", traits: {"smithy.api#error" => "client"})
 
-    CityCoordinates.add_member(:latitude, ::Smithy::Schema::Shapes::ShapeRef.new(shape: ::Smithy::Schema::Shapes::Prelude::Float, location_name: "latitude", traits: {"smithy.api#required" => {}}))
-    CityCoordinates.add_member(:longitude, ::Smithy::Schema::Shapes::ShapeRef.new(shape: ::Smithy::Schema::Shapes::Prelude::Float, location_name: "longitude", traits: {"smithy.api#required" => {}}))
+    CityCoordinates.add_member(:latitude, ::Smithy::Schema::Shapes::MemberShape.new(target: ::Smithy::Schema::Shapes::Prelude::Float, location_name: "latitude", traits: {"smithy.api#required" => {}}))
+    CityCoordinates.add_member(:longitude, ::Smithy::Schema::Shapes::MemberShape.new(target: ::Smithy::Schema::Shapes::Prelude::Float, location_name: "longitude", traits: {"smithy.api#required" => {}}))
     CityCoordinates.type = Types::CityCoordinates
-    CitySummaries.member = ::Smithy::Schema::Shapes::ShapeRef.new(shape: CitySummary)
-    CitySummary.add_member(:city_id, ::Smithy::Schema::Shapes::ShapeRef.new(shape: CityId, location_name: "cityId", traits: {"smithy.api#required" => {}}))
-    CitySummary.add_member(:name, ::Smithy::Schema::Shapes::ShapeRef.new(shape: ::Smithy::Schema::Shapes::Prelude::String, location_name: "name", traits: {"smithy.api#required" => {}}))
+    CitySummaries.member = ::Smithy::Schema::Shapes::MemberShape.new(target: CitySummary)
+    CitySummary.add_member(:city_id, ::Smithy::Schema::Shapes::MemberShape.new(target: CityId, location_name: "cityId", traits: {"smithy.api#required" => {}}))
+    CitySummary.add_member(:name, ::Smithy::Schema::Shapes::MemberShape.new(target: ::Smithy::Schema::Shapes::Prelude::String, location_name: "name", traits: {"smithy.api#required" => {}}))
     CitySummary.type = Types::CitySummary
-    GetCityInput.add_member(:city_id, ::Smithy::Schema::Shapes::ShapeRef.new(shape: CityId, location_name: "cityId", traits: {"smithy.api#required" => {}}))
+    GetCityInput.add_member(:city_id, ::Smithy::Schema::Shapes::MemberShape.new(target: CityId, location_name: "cityId", traits: {"smithy.api#required" => {}}))
     GetCityInput.type = Types::GetCityInput
-    GetCityOutput.add_member(:name, ::Smithy::Schema::Shapes::ShapeRef.new(shape: ::Smithy::Schema::Shapes::Prelude::String, location_name: "name", traits: {"smithy.api#notProperty" => {}, "smithy.api#required" => {}}))
-    GetCityOutput.add_member(:coordinates, ::Smithy::Schema::Shapes::ShapeRef.new(shape: CityCoordinates, location_name: "coordinates", traits: {"smithy.api#required" => {}}))
+    GetCityOutput.add_member(:name, ::Smithy::Schema::Shapes::MemberShape.new(target: ::Smithy::Schema::Shapes::Prelude::String, location_name: "name", traits: {"smithy.api#notProperty" => {}, "smithy.api#required" => {}}))
+    GetCityOutput.add_member(:coordinates, ::Smithy::Schema::Shapes::MemberShape.new(target: CityCoordinates, location_name: "coordinates", traits: {"smithy.api#required" => {}}))
     GetCityOutput.type = Types::GetCityOutput
-    GetCurrentTimeOutput.add_member(:time, ::Smithy::Schema::Shapes::ShapeRef.new(shape: ::Smithy::Schema::Shapes::Prelude::Timestamp, location_name: "time", traits: {"smithy.api#required" => {}}))
+    GetCurrentTimeOutput.add_member(:time, ::Smithy::Schema::Shapes::MemberShape.new(target: ::Smithy::Schema::Shapes::Prelude::Timestamp, location_name: "time", traits: {"smithy.api#required" => {}}))
     GetCurrentTimeOutput.type = Types::GetCurrentTimeOutput
-    GetForecastInput.add_member(:city_id, ::Smithy::Schema::Shapes::ShapeRef.new(shape: CityId, location_name: "cityId", traits: {"smithy.api#required" => {}}))
+    GetForecastInput.add_member(:city_id, ::Smithy::Schema::Shapes::MemberShape.new(target: CityId, location_name: "cityId", traits: {"smithy.api#required" => {}}))
     GetForecastInput.type = Types::GetForecastInput
-    GetForecastOutput.add_member(:chance_of_rain, ::Smithy::Schema::Shapes::ShapeRef.new(shape: ::Smithy::Schema::Shapes::Prelude::Float, location_name: "chanceOfRain"))
+    GetForecastOutput.add_member(:chance_of_rain, ::Smithy::Schema::Shapes::MemberShape.new(target: ::Smithy::Schema::Shapes::Prelude::Float, location_name: "chanceOfRain"))
     GetForecastOutput.type = Types::GetForecastOutput
-    ListCitiesInput.add_member(:next_token, ::Smithy::Schema::Shapes::ShapeRef.new(shape: ::Smithy::Schema::Shapes::Prelude::String, location_name: "nextToken"))
-    ListCitiesInput.add_member(:page_size, ::Smithy::Schema::Shapes::ShapeRef.new(shape: ::Smithy::Schema::Shapes::Prelude::Integer, location_name: "pageSize"))
+    ListCitiesInput.add_member(:next_token, ::Smithy::Schema::Shapes::MemberShape.new(target: ::Smithy::Schema::Shapes::Prelude::String, location_name: "nextToken"))
+    ListCitiesInput.add_member(:page_size, ::Smithy::Schema::Shapes::MemberShape.new(target: ::Smithy::Schema::Shapes::Prelude::Integer, location_name: "pageSize"))
     ListCitiesInput.type = Types::ListCitiesInput
-    ListCitiesOutput.add_member(:next_token, ::Smithy::Schema::Shapes::ShapeRef.new(shape: ::Smithy::Schema::Shapes::Prelude::String, location_name: "nextToken"))
-    ListCitiesOutput.add_member(:items, ::Smithy::Schema::Shapes::ShapeRef.new(shape: CitySummaries, location_name: "items", traits: {"smithy.api#required" => {}}))
+    ListCitiesOutput.add_member(:next_token, ::Smithy::Schema::Shapes::MemberShape.new(target: ::Smithy::Schema::Shapes::Prelude::String, location_name: "nextToken"))
+    ListCitiesOutput.add_member(:items, ::Smithy::Schema::Shapes::MemberShape.new(target: CitySummaries, location_name: "items", traits: {"smithy.api#required" => {}}))
     ListCitiesOutput.type = Types::ListCitiesOutput
-    NoSuchResource.add_member(:resource_type, ::Smithy::Schema::Shapes::ShapeRef.new(shape: ::Smithy::Schema::Shapes::Prelude::String, location_name: "resourceType", traits: {"smithy.api#required" => {}}))
+    NoSuchResource.add_member(:resource_type, ::Smithy::Schema::Shapes::MemberShape.new(target: ::Smithy::Schema::Shapes::Prelude::String, location_name: "resourceType", traits: {"smithy.api#required" => {}}))
     NoSuchResource.type = Types::NoSuchResource
 
     Weather = ::Smithy::Schema::Shapes::ServiceShape.new do |service|
@@ -54,30 +54,30 @@ module Schema
       service.add_operation(:get_city, ::Smithy::Schema::Shapes::OperationShape.new do |operation|
         operation.id = "example.weather#GetCity"
         operation.name = "GetCity"
-        operation.input = ::Smithy::Schema::Shapes::ShapeRef.new(shape: GetCityInput)
-        operation.output = ::Smithy::Schema::Shapes::ShapeRef.new(shape: GetCityOutput)
-        operation.errors << ::Smithy::Schema::Shapes::ShapeRef.new(shape: NoSuchResource)
+        operation.input = ::Smithy::Schema::Shapes::MemberShape.new(target: GetCityInput)
+        operation.output = ::Smithy::Schema::Shapes::MemberShape.new(target: GetCityOutput)
+        operation.errors << ::Smithy::Schema::Shapes::MemberShape.new(target: NoSuchResource)
         operation.traits = {"smithy.api#readonly" => {}}
       end)
       service.add_operation(:get_current_time, ::Smithy::Schema::Shapes::OperationShape.new do |operation|
         operation.id = "example.weather#GetCurrentTime"
         operation.name = "GetCurrentTime"
-        operation.input = ::Smithy::Schema::Shapes::ShapeRef.new(shape: ::Smithy::Schema::Shapes::Prelude::Unit)
-        operation.output = ::Smithy::Schema::Shapes::ShapeRef.new(shape: GetCurrentTimeOutput)
+        operation.input = ::Smithy::Schema::Shapes::MemberShape.new(target: ::Smithy::Schema::Shapes::Prelude::Unit)
+        operation.output = ::Smithy::Schema::Shapes::MemberShape.new(target: GetCurrentTimeOutput)
         operation.traits = {"smithy.api#readonly" => {}}
       end)
       service.add_operation(:get_forecast, ::Smithy::Schema::Shapes::OperationShape.new do |operation|
         operation.id = "example.weather#GetForecast"
         operation.name = "GetForecast"
-        operation.input = ::Smithy::Schema::Shapes::ShapeRef.new(shape: GetForecastInput)
-        operation.output = ::Smithy::Schema::Shapes::ShapeRef.new(shape: GetForecastOutput)
+        operation.input = ::Smithy::Schema::Shapes::MemberShape.new(target: GetForecastInput)
+        operation.output = ::Smithy::Schema::Shapes::MemberShape.new(target: GetForecastOutput)
         operation.traits = {"smithy.api#readonly" => {}}
       end)
       service.add_operation(:list_cities, ::Smithy::Schema::Shapes::OperationShape.new do |operation|
         operation.id = "example.weather#ListCities"
         operation.name = "ListCities"
-        operation.input = ::Smithy::Schema::Shapes::ShapeRef.new(shape: ListCitiesInput)
-        operation.output = ::Smithy::Schema::Shapes::ShapeRef.new(shape: ListCitiesOutput)
+        operation.input = ::Smithy::Schema::Shapes::MemberShape.new(target: ListCitiesInput)
+        operation.output = ::Smithy::Schema::Shapes::MemberShape.new(target: ListCitiesOutput)
         operation.traits = {"smithy.api#readonly" => {}}
         operation[:paginator] = Paginators::ListCities.new
       end)

From 969094b64425673e5d70d30c0e3f4d646ff66429 Mon Sep 17 00:00:00 2001
From: Juli Tera <terajul@amazon.com>
Date: Thu, 4 Jun 2026 09:06:21 -0700
Subject: [PATCH 05/23] Update Json codec with SERDE

---
 gems/smithy-json/lib/smithy-json/builder.rb | 55 ++++++++---------
 gems/smithy-json/lib/smithy-json/parser.rb  | 67 ++++++++++-----------
 2 files changed, 59 insertions(+), 63 deletions(-)

diff --git a/gems/smithy-json/lib/smithy-json/builder.rb b/gems/smithy-json/lib/smithy-json/builder.rb
index 1d7b846c9..9095fe04f 100644
--- a/gems/smithy-json/lib/smithy-json/builder.rb
+++ b/gems/smithy-json/lib/smithy-json/builder.rb
@@ -13,21 +13,20 @@ def initialize(options = {})
       end
 
       def build(shape, data)
-        ref = shape.is_a?(MemberShape) ? shape : MemberShape.new(target: shape)
-        Smithy::Json.dump(shape(ref, data))
+        Smithy::Json.dump(serialize_shape(shape, data))
       end
 
       private
 
-      def shape(ref, value) # rubocop:disable Metrics/CyclomaticComplexity
-        case ref.target
+      def serialize_shape(shape, value) # rubocop:disable Metrics/CyclomaticComplexity
+        case shape.target
         when BlobShape then blob(value)
         when FloatShape then float(value)
-        when ListShape then list(ref, value)
-        when MapShape then map(ref, value)
-        when StructureShape then structure(ref, value)
-        when TimestampShape then timestamp(ref, value)
-        when UnionShape then union(ref, value)
+        when ListShape then list(shape, value)
+        when MapShape then map(shape, value)
+        when StructureShape then structure(shape, value)
+        when TimestampShape then timestamp(shape, value)
+        when UnionShape then union(shape, value)
         else value
         end
       end
@@ -48,36 +47,34 @@ def float(value)
         end
       end
 
-      def list(ref, values)
+      def list(shape, values)
         return if values.nil?
 
-        shape = ref.target
         values.collect do |value|
-          shape(shape.member, value)
+          serialize_shape(shape.target.member, value)
         end
       end
 
-      def map(ref, values)
+      def map(shape, values)
         return if values.nil?
 
-        shape = ref.target
         values.each.with_object({}) do |(key, value), data|
-          data[key] = shape(shape.value, value)
+          data[key] = serialize_shape(shape.target.value, value)
         end
       end
 
-      def structure(ref, values)
+      def structure(shape, values)
         return if values.nil?
 
-        ref.target.members.each_with_object({}) do |(member_name, member_ref), data|
+        shape.target.members.each_with_object({}) do |(member_name, member_shape), data|
           value = values[member_name]
-          data[location_name(member_ref)] = shape(member_ref, value) unless value.nil?
+          data[location_name(member_shape)] = serialize_shape(member_shape, value) unless value.nil?
         end
       end
 
-      def timestamp(ref, value)
+      def timestamp(shape, value)
         trait = 'smithy.api#timestampFormat'
-        case ref.traits[trait] || ref.target.traits[trait]
+        case shape.traits[trait] || shape.target.traits[trait]
         when 'date-time' then value.utc.iso8601
         when 'http-date' then value.utc.httpdate
         else
@@ -86,27 +83,27 @@ def timestamp(ref, value)
         end
       end
 
-      def union(ref, values) # rubocop:disable Metrics/AbcSize
+      def union(shape, values) # rubocop:disable Metrics/AbcSize
         return if values.nil?
 
         data = {}
         if values.is_a?(Schema::Union)
-          _name, member_ref = ref.target.member_by_type(values.class)
-          data[location_name(member_ref)] = shape(member_ref, values.value)
+          _name, member_ref = shape.target.member_by_type(values.class)
+          data[location_name(member_ref)] = serialize_shape(member_ref, values.value)
         else
           key, value = values.first
-          if ref.target.member?(key)
-            member_ref = ref.target.member(key)
-            data[location_name(member_ref)] = shape(member_ref, value)
+          if shape.target.member?(key)
+            member_ref = shape.target.member(key)
+            data[location_name(member_ref)] = serialize_shape(member_ref, value)
           end
         end
         data
       end
 
-      def location_name(ref)
-        return ref.location_name unless @json_name
+      def location_name(member)
+        return member.location_name unless @json_name
 
-        ref.traits['smithy.api#jsonName'] || ref.location_name
+        member.traits['smithy.api#jsonName'] || member.location_name
       end
     end
   end
diff --git a/gems/smithy-json/lib/smithy-json/parser.rb b/gems/smithy-json/lib/smithy-json/parser.rb
index a99e8d0b4..5aa5b893c 100644
--- a/gems/smithy-json/lib/smithy-json/parser.rb
+++ b/gems/smithy-json/lib/smithy-json/parser.rb
@@ -12,24 +12,23 @@ def initialize(options = {})
         @json_name = options[:json_name] || false
       end
 
-      def parse(shape, bytes, target = nil)
+      def parse(shape, bytes, result = nil)
         return {} if bytes.empty?
 
-        ref = shape.is_a?(MemberShape) ? shape : MemberShape.new(target: shape)
-        shape(ref, Smithy::Json.load(bytes), target)
+        deserialize_shape(shape, Smithy::Json.load(bytes), result)
       end
 
       private
 
-      def shape(ref, value, target = nil) # rubocop:disable Metrics/CyclomaticComplexity
-        case ref.target
+      def deserialize_shape(shape, value, result = nil) # rubocop:disable Metrics/CyclomaticComplexity
+        case shape.target
         when BlobShape then Base64.decode64(value)
         when FloatShape then float(value)
-        when ListShape then list(ref, value, target)
-        when MapShape then map(ref, value, target)
-        when StructureShape then structure(ref, value, target)
+        when ListShape then list(shape, value, result)
+        when MapShape then map(shape, value, result)
+        when StructureShape then structure(shape, value, result)
         when TimestampShape then timestamp(value)
-        when UnionShape then union(ref, value, target)
+        when UnionShape then union(shape, value, result)
         else value
         end
       end
@@ -43,37 +42,37 @@ def float(value)
         end
       end
 
-      def list(ref, values, target = nil)
+      def list(shape, values, result = nil)
         return if values.nil?
 
-        target = [] if target.nil?
+        result = [] if result.nil?
         values.each do |value|
-          next if value.nil? && !sparse?(ref.target)
+          next if value.nil? && !sparse?(shape.target)
 
-          target << shape(ref.target.member, value)
+          result << deserialize_shape(shape.target.member, value)
         end
-        target
+        result
       end
 
-      def map(ref, values, target = nil)
-        target = {} if target.nil?
+      def map(shape, values, result = nil)
+        result = {} if result.nil?
         values.each do |key, value|
-          next if value.nil? && !sparse?(ref.target)
+          next if value.nil? && !sparse?(shape.target)
 
-          target[key] = shape(ref.target.value, value)
+          result[key] = deserialize_shape(shape.target.value, value)
         end
-        target
+        result
       end
 
-      def structure(ref, values, target = nil)
+      def structure(shape, values, result = nil)
         return if values.nil?
 
-        target = ref.target.type.new if target.nil?
-        ref.target.members.each do |member_name, member_ref|
-          value = values[location_name(member_ref)]
-          target[member_name] = shape(member_ref, value) unless value.nil?
+        result = shape.target.type.new if result.nil?
+        shape.target.members.each do |member_name, member_shape|
+          value = values[location_name(member_shape)]
+          result[member_name] = deserialize_shape(member_shape, value) unless value.nil?
         end
-        target
+        result
       end
 
       def timestamp(value)
@@ -89,24 +88,24 @@ def timestamp(value)
         end
       end
 
-      def union(ref, values, target = nil) # rubocop:disable Metrics/AbcSize
-        ref.target.members.each do |member_name, member_ref|
-          value = values[location_name(member_ref)]
+      def union(shape, values, result = nil) # rubocop:disable Metrics/AbcSize
+        shape.target.members.each do |member_name, member_shape|
+          value = values[location_name(member_shape)]
           next if value.nil?
 
-          target = ref.target.member_type(member_name) if target.nil?
-          return target.new(member_name => shape(member_ref, value))
+          result = shape.target.member_type(member_name) if result.nil?
+          return result.new(member_name => deserialize_shape(member_shape, value))
         end
 
         values.delete('__type')
         key, value = values.first
-        ref.target.member_type(:unknown).new(unknown: { key => value })
+        shape.target.member_type(:unknown).new(unknown: { key => value })
       end
 
-      def location_name(ref)
-        return ref.location_name unless @json_name
+      def location_name(member)
+        return member.location_name unless @json_name
 
-        ref.traits['smithy.api#jsonName'] || ref.location_name
+        member.traits['smithy.api#jsonName'] || member.location_name
       end
 
       def sparse?(shape)

From f64addf74f860e3c0556dbe84ebd7c91caf0b922 Mon Sep 17 00:00:00 2001
From: Juli Tera <terajul@amazon.com>
Date: Thu, 4 Jun 2026 12:47:13 -0700
Subject: [PATCH 06/23] Remove MemberShape wrapper from operation input/output

---
 .../lib/smithy/templates/client/schema.erb    |   4 +-
 gems/smithy/lib/smithy/views/client/schema.rb | 140 +++++++++---------
 .../spec/interfaces/rename_shapes_spec.rb     |   4 +-
 .../interfaces/synthetic_input_output_spec.rb |  12 +-
 4 files changed, 81 insertions(+), 79 deletions(-)

diff --git a/gems/smithy/lib/smithy/templates/client/schema.erb b/gems/smithy/lib/smithy/templates/client/schema.erb
index b4f51b6a0..e4dd12b03 100644
--- a/gems/smithy/lib/smithy/templates/client/schema.erb
+++ b/gems/smithy/lib/smithy/templates/client/schema.erb
@@ -50,8 +50,8 @@ module <%= module_name %>
       service.add_operation(:<%= shape.name.underscore %>, ::Smithy::Schema::Shapes::OperationShape.new do |operation|
         operation.id = "<%= shape.id %>"
         operation.name = "<%= shape.name %>"
-        operation.input = <%= shape.input.initializer %>
-        operation.output = <%= shape.output.initializer %>
+        operation.input = <%= shape.input %>
+        operation.output = <%= shape.output %>
 <% shape.errors.each do |error| -%>
         operation.errors << <%= error.initializer %>
 <% end -%>
diff --git a/gems/smithy/lib/smithy/views/client/schema.rb b/gems/smithy/lib/smithy/views/client/schema.rb
index 36f44b20f..2c20265a1 100644
--- a/gems/smithy/lib/smithy/views/client/schema.rb
+++ b/gems/smithy/lib/smithy/views/client/schema.rb
@@ -54,6 +54,58 @@ def build_shape(id, shape)
           end
         end
 
+        # Shared resolution logic for the schema view classes. Mixed into the
+        # shape views ({Shape} and its subclasses), {OperationShape}, and
+        # {MemberShape} — every class that needs to turn an absolute shape ID
+        # into the Ruby constant the generated schema references. Relies on the
+        # including class exposing the unwrapped service hash as +@service+.
+        # @api private
+        module SchemaHelper
+          # Maps Smithy prelude shape IDs to their generated +Prelude::*+
+          # constant names. Prelude shapes are shared built-ins and are never
+          # emitted per-service, so they resolve to a fixed constant rather than
+          # a service-local one.
+          PRELUDE_SHAPES_MAP = {
+            'smithy.api#BigInteger' => 'Prelude::BigInteger',
+            'smithy.api#BigDecimal' => 'Prelude::BigDecimal',
+            'smithy.api#Blob' => 'Prelude::Blob',
+            'smithy.api#Boolean' => 'Prelude::Boolean',
+            'smithy.api#Byte' => 'Prelude::Byte',
+            'smithy.api#Document' => 'Prelude::Document',
+            'smithy.api#Double' => 'Prelude::Double',
+            'smithy.api#Float' => 'Prelude::Float',
+            'smithy.api#Integer' => 'Prelude::Integer',
+            'smithy.api#Long' => 'Prelude::Long',
+            'smithy.api#PrimitiveBoolean' => 'Prelude::PrimitiveBoolean',
+            'smithy.api#PrimitiveByte' => 'Prelude::PrimitiveByte',
+            'smithy.api#PrimitiveDouble' => 'Prelude::PrimitiveDouble',
+            'smithy.api#PrimitiveFloat' => 'Prelude::PrimitiveFloat',
+            'smithy.api#PrimitiveInteger' => 'Prelude::PrimitiveInteger',
+            'smithy.api#PrimitiveLong' => 'Prelude::PrimitiveLong',
+            'smithy.api#PrimitiveShort' => 'Prelude::PrimitiveShort',
+            'smithy.api#Short' => 'Prelude::Short',
+            'smithy.api#String' => 'Prelude::String',
+            'smithy.api#Timestamp' => 'Prelude::Timestamp',
+            'smithy.api#Unit' => 'Prelude::Unit'
+          }.freeze
+
+          # Resolves an absolute shape ID to the Ruby constant the generated
+          # schema references for it.
+          #
+          # - Prelude shapes resolve to their fully-qualified
+          #   +::Smithy::Schema::Shapes::Prelude::*+ constant.
+          # - All other shapes resolve to a service-local constant name,
+          #   honoring the service's +rename+ map when present.
+          #
+          # @param [String] id Absolute shape ID (e.g. +"example.weather#GetCityInput"+).
+          # @return [String] The constant reference as a string (e.g. +"GetCityInput"+).
+          def shape_name_from_id(id)
+            return "::Smithy::Schema::Shapes::#{PRELUDE_SHAPES_MAP[id]}" if PRELUDE_SHAPES_MAP.key?(id)
+
+            (@service.dig('rename', id) || Model::Shape.name(id)).camelize
+          end
+        end
+
         # @api private
         class ServiceShape
           OMITTED_TRAITS = %w[
@@ -78,6 +130,8 @@ def name
 
         # @api private
         class OperationShape
+          include SchemaHelper
+
           OMITTED_TRAITS = %w[
             smithy.api#documentation
             smithy.api#examples
@@ -92,8 +146,8 @@ def initialize(service, id, shape)
             _, @service = service.first
             @id = id
             @name = (@service.dig('rename', @id) || Model::Shape.name(@id)).camelize
-            @input = build_input(shape['input'])
-            @output = build_output(shape['output'])
+            @input = shape_name_from_id(shape['input']['target'])
+            @output = shape_name_from_id(shape['output']['target'])
             @errors = build_errors(shape.fetch('errors', []))
             @traits = shape.fetch('traits', {})
           end
@@ -114,14 +168,6 @@ def paginator
 
           private
 
-          def build_input(input)
-            MemberShape.new(@service, nil, input)
-          end
-
-          def build_output(output)
-            MemberShape.new(@service, nil, output)
-          end
-
           def build_errors(errors)
             errors = Set.new(@service.fetch('errors', [])).merge(errors)
             errors.map { |error| MemberShape.new(@service, nil, error) }
@@ -130,6 +176,8 @@ def build_errors(errors)
 
         # @api private
         class Shape
+          include SchemaHelper
+
           OMITTED_TRAITS = %w[
             smithy.api#documentation
           ].freeze
@@ -172,6 +220,12 @@ def initializer
             options_str += ", traits: #{@traits}" unless @traits.empty?
             "::Smithy::Schema::Shapes::#{SHAPE_CLASS_MAP[@type]}.new(#{options_str})"
           end
+
+          private
+
+          def build_members(members)
+            members.map { |name, member| MemberShape.new(@service, name, member) }
+          end
         end
 
         # @api private
@@ -184,7 +238,7 @@ class StructureShape < Shape
 
           def initialize(service, id, shape)
             super
-            @members = build_shape_refs(shape['members'])
+            @members = build_members(shape['members'])
             @traits = shape.fetch('traits', {}).except(*OMITTED_TRAITS)
           end
 
@@ -201,44 +255,26 @@ def http_payload?
           def http_payload
             @members.find(&:http_payload).http_payload
           end
-
-          private
-
-          def build_shape_refs(members)
-            members.map { |name, member| MemberShape.new(@service, name, member) }
-          end
         end
 
         # @api private
         class EnumShape < Shape
           def initialize(service, id, shape)
             super
-            @members = build_shape_refs(shape['members'])
+            @members = build_members(shape['members'])
           end
 
           attr_reader :members
-
-          private
-
-          def build_shape_refs(members)
-            members.map { |name, shape_ref| MemberShape.new(@service, name, shape_ref) }
-          end
         end
 
         # @api private
         class IntEnumShape < Shape
           def initialize(service, id, shape)
             super
-            @members = build_shape_refs(shape['members'])
+            @members = build_members(shape['members'])
           end
 
           attr_reader :members
-
-          private
-
-          def build_shape_refs(members)
-            members.map { |name, member| MemberShape.new(@service, name, member) }
-          end
         end
 
         # @api private
@@ -266,7 +302,7 @@ def initialize(service, id, shape)
         class UnionShape < Shape
           def initialize(service, id, shape)
             super
-            @members = build_shape_refs(shape['members'])
+            @members = build_members(shape['members'])
           end
 
           attr_reader :members
@@ -278,49 +314,21 @@ def type_class
           def union_type(shape_ref)
             "#{type_class}::#{shape_ref.location_name.camelize}"
           end
-
-          private
-
-          def build_shape_refs(members)
-            members.map { |name, member| MemberShape.new(@service, name, member) }
-          end
         end
 
         # @api private
         class MemberShape
+          include SchemaHelper
+
           OMITTED_TRAITS = %w[
             smithy.api#documentation
           ].freeze
 
-          PRELUDE_SHAPES_MAP = {
-            'smithy.api#BigInteger' => 'Prelude::BigInteger',
-            'smithy.api#BigDecimal' => 'Prelude::BigDecimal',
-            'smithy.api#Blob' => 'Prelude::Blob',
-            'smithy.api#Boolean' => 'Prelude::Boolean',
-            'smithy.api#Byte' => 'Prelude::Byte',
-            'smithy.api#Document' => 'Prelude::Document',
-            'smithy.api#Double' => 'Prelude::Double',
-            'smithy.api#Float' => 'Prelude::Float',
-            'smithy.api#Integer' => 'Prelude::Integer',
-            'smithy.api#Long' => 'Prelude::Long',
-            'smithy.api#PrimitiveBoolean' => 'Prelude::PrimitiveBoolean',
-            'smithy.api#PrimitiveByte' => 'Prelude::PrimitiveByte',
-            'smithy.api#PrimitiveDouble' => 'Prelude::PrimitiveDouble',
-            'smithy.api#PrimitiveFloat' => 'Prelude::PrimitiveFloat',
-            'smithy.api#PrimitiveInteger' => 'Prelude::PrimitiveInteger',
-            'smithy.api#PrimitiveLong' => 'Prelude::PrimitiveLong',
-            'smithy.api#PrimitiveShort' => 'Prelude::PrimitiveShort',
-            'smithy.api#Short' => 'Prelude::Short',
-            'smithy.api#String' => 'Prelude::String',
-            'smithy.api#Timestamp' => 'Prelude::Timestamp',
-            'smithy.api#Unit' => 'Prelude::Unit'
-          }.freeze
-
           def initialize(service, location_name, shape_ref)
             @service = service
             @name = location_name.underscore if location_name
             @location_name = location_name
-            @target = shape(shape_ref['target'])
+            @target = shape_name_from_id(shape_ref['target'])
             @traits = shape_ref.fetch('traits', {}).except(*OMITTED_TRAITS)
           end
 
@@ -333,12 +341,6 @@ def initializer
             "::Smithy::Schema::Shapes::MemberShape.new(#{options_str})"
           end
 
-          def shape(id)
-            return "::Smithy::Schema::Shapes::#{PRELUDE_SHAPES_MAP[id]}" if PRELUDE_SHAPES_MAP.key?(id)
-
-            (@service.dig('rename', id) || Model::Shape.name(id)).camelize
-          end
-
           def http_payload?
             @traits.key?('smithy.api#httpPayload')
           end
diff --git a/gems/smithy/spec/interfaces/rename_shapes_spec.rb b/gems/smithy/spec/interfaces/rename_shapes_spec.rb
index a52bea17c..863561eed 100644
--- a/gems/smithy/spec/interfaces/rename_shapes_spec.rb
+++ b/gems/smithy/spec/interfaces/rename_shapes_spec.rb
@@ -37,8 +37,8 @@
       it 'assigns renamed shapes to operation inputs and outputs' do
         client = RenameShapes::Client.new
         operation = client.config.service.operation(:operation)
-        expect(operation.input.target.type).to eq(RenameShapes::Types::RenamedOperationInput)
-        expect(operation.output.target.type).to eq(RenameShapes::Types::RenamedOperationOutput)
+        expect(operation.input.type).to eq(RenameShapes::Types::RenamedOperationInput)
+        expect(operation.output.type).to eq(RenameShapes::Types::RenamedOperationOutput)
       end
     end
   end
diff --git a/gems/smithy/spec/interfaces/synthetic_input_output_spec.rb b/gems/smithy/spec/interfaces/synthetic_input_output_spec.rb
index b7de49521..f37ea33f4 100644
--- a/gems/smithy/spec/interfaces/synthetic_input_output_spec.rb
+++ b/gems/smithy/spec/interfaces/synthetic_input_output_spec.rb
@@ -37,25 +37,25 @@
       it 'assigns synthetic input and output shapes to the operation' do
         client = SyntheticInputOutput::Client.new
         operation = client.config.service.operation(:operation)
-        expect(operation.input.target.type).to eq(SyntheticInputOutput::Types::OperationInput)
-        expect(operation.output.target.type).to eq(SyntheticInputOutput::Types::OperationOutput)
+        expect(operation.input.type).to eq(SyntheticInputOutput::Types::OperationInput)
+        expect(operation.output.type).to eq(SyntheticInputOutput::Types::OperationOutput)
       end
 
       it 'preserves input and output shapes on the operation with the input and output trait' do
         client = SyntheticInputOutput::Client.new
         operation = client.config.service.operation(:operation_with_input_and_output_traits)
-        expect(operation.input.target.type)
+        expect(operation.input.type)
           .to eq(SyntheticInputOutput::Types::OperationWithInputAndOutputTraitsInput)
-        expect(operation.output.target.type)
+        expect(operation.output.type)
           .to eq(SyntheticInputOutput::Types::OperationWithInputAndOutputTraitsOutput)
       end
 
       it 'handles naming conflicts by inserting Operation between the operation name and the suffix' do
         client = SyntheticInputOutput::Client.new
         operation = client.config.service.operation(:operation_with_naming_conflict)
-        expect(operation.input.target.type)
+        expect(operation.input.type)
           .to eq(SyntheticInputOutput::Types::OperationWithNamingConflictOperationInput)
-        expect(operation.output.target.type)
+        expect(operation.output.type)
           .to eq(SyntheticInputOutput::Types::OperationWithNamingConflictOperationOutput)
       end
     end

From adec0fbc02cc59cbb9f4c475131fb7ec59eb4c82 Mon Sep 17 00:00:00 2001
From: Juli Tera <terajul@amazon.com>
Date: Thu, 4 Jun 2026 12:47:28 -0700
Subject: [PATCH 07/23] Update projections

---
 projections/shapes/lib/shapes/schema.rb   |  4 ++--
 projections/weather/lib/weather/schema.rb | 16 ++++++++--------
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/projections/shapes/lib/shapes/schema.rb b/projections/shapes/lib/shapes/schema.rb
index 61a8da789..f4dfa0810 100644
--- a/projections/shapes/lib/shapes/schema.rb
+++ b/projections/shapes/lib/shapes/schema.rb
@@ -89,8 +89,8 @@ module Schema
       service.add_operation(:operation, ::Smithy::Schema::Shapes::OperationShape.new do |operation|
         operation.id = "smithy.ruby.tests#Operation"
         operation.name = "Operation"
-        operation.input = ::Smithy::Schema::Shapes::MemberShape.new(target: OperationInput)
-        operation.output = ::Smithy::Schema::Shapes::MemberShape.new(target: OperationOutput)
+        operation.input = OperationInput
+        operation.output = OperationOutput
         operation.traits = {"smithy.ruby.tests#shape" => {}}
       end)
     end
diff --git a/projections/weather/lib/weather/schema.rb b/projections/weather/lib/weather/schema.rb
index a63e42308..7eff0acd0 100644
--- a/projections/weather/lib/weather/schema.rb
+++ b/projections/weather/lib/weather/schema.rb
@@ -54,30 +54,30 @@ module Schema
       service.add_operation(:get_city, ::Smithy::Schema::Shapes::OperationShape.new do |operation|
         operation.id = "example.weather#GetCity"
         operation.name = "GetCity"
-        operation.input = ::Smithy::Schema::Shapes::MemberShape.new(target: GetCityInput)
-        operation.output = ::Smithy::Schema::Shapes::MemberShape.new(target: GetCityOutput)
+        operation.input = GetCityInput
+        operation.output = GetCityOutput
         operation.errors << ::Smithy::Schema::Shapes::MemberShape.new(target: NoSuchResource)
         operation.traits = {"smithy.api#readonly" => {}}
       end)
       service.add_operation(:get_current_time, ::Smithy::Schema::Shapes::OperationShape.new do |operation|
         operation.id = "example.weather#GetCurrentTime"
         operation.name = "GetCurrentTime"
-        operation.input = ::Smithy::Schema::Shapes::MemberShape.new(target: ::Smithy::Schema::Shapes::Prelude::Unit)
-        operation.output = ::Smithy::Schema::Shapes::MemberShape.new(target: GetCurrentTimeOutput)
+        operation.input = ::Smithy::Schema::Shapes::Prelude::Unit
+        operation.output = GetCurrentTimeOutput
         operation.traits = {"smithy.api#readonly" => {}}
       end)
       service.add_operation(:get_forecast, ::Smithy::Schema::Shapes::OperationShape.new do |operation|
         operation.id = "example.weather#GetForecast"
         operation.name = "GetForecast"
-        operation.input = ::Smithy::Schema::Shapes::MemberShape.new(target: GetForecastInput)
-        operation.output = ::Smithy::Schema::Shapes::MemberShape.new(target: GetForecastOutput)
+        operation.input = GetForecastInput
+        operation.output = GetForecastOutput
         operation.traits = {"smithy.api#readonly" => {}}
       end)
       service.add_operation(:list_cities, ::Smithy::Schema::Shapes::OperationShape.new do |operation|
         operation.id = "example.weather#ListCities"
         operation.name = "ListCities"
-        operation.input = ::Smithy::Schema::Shapes::MemberShape.new(target: ListCitiesInput)
-        operation.output = ::Smithy::Schema::Shapes::MemberShape.new(target: ListCitiesOutput)
+        operation.input = ListCitiesInput
+        operation.output = ListCitiesOutput
         operation.traits = {"smithy.api#readonly" => {}}
         operation[:paginator] = Paginators::ListCities.new
       end)

From 1b9b8c7488f2ce440701dc7fdb50393177f6e3da Mon Sep 17 00:00:00 2001
From: Juli Tera <terajul@amazon.com>
Date: Thu, 4 Jun 2026 12:54:58 -0700
Subject: [PATCH 08/23] Remove shape refs

---
 gems/smithy/lib/smithy/views/client/schema.rb | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/gems/smithy/lib/smithy/views/client/schema.rb b/gems/smithy/lib/smithy/views/client/schema.rb
index 2c20265a1..56ff386d4 100644
--- a/gems/smithy/lib/smithy/views/client/schema.rb
+++ b/gems/smithy/lib/smithy/views/client/schema.rb
@@ -311,8 +311,8 @@ def type_class
             "Types::#{(@service.dig('rename', @id) || Model::Shape.name(@id)).camelize}"
           end
 
-          def union_type(shape_ref)
-            "#{type_class}::#{shape_ref.location_name.camelize}"
+          def union_type(member)
+            "#{type_class}::#{member.location_name.camelize}"
           end
         end
 
@@ -324,12 +324,12 @@ class MemberShape
             smithy.api#documentation
           ].freeze
 
-          def initialize(service, location_name, shape_ref)
+          def initialize(service, location_name, member_def)
             @service = service
             @name = location_name.underscore if location_name
             @location_name = location_name
-            @target = shape_name_from_id(shape_ref['target'])
-            @traits = shape_ref.fetch('traits', {}).except(*OMITTED_TRAITS)
+            @target = shape_name_from_id(member_def['target'])
+            @traits = member_def.fetch('traits', {}).except(*OMITTED_TRAITS)
           end
 
           attr_reader :name, :location_name

From 6108a77232557c358fb3fbb3be2684fbb742b322 Mon Sep 17 00:00:00 2001
From: Juli Tera <terajul@amazon.com>
Date: Thu, 4 Jun 2026 13:03:55 -0700
Subject: [PATCH 09/23] Refacor CBOR codec to new standards

---
 gems/smithy-cbor/lib/smithy-cbor/builder.rb | 45 +++++++--------
 gems/smithy-cbor/lib/smithy-cbor/parser.rb  | 61 ++++++++++-----------
 2 files changed, 51 insertions(+), 55 deletions(-)

diff --git a/gems/smithy-cbor/lib/smithy-cbor/builder.rb b/gems/smithy-cbor/lib/smithy-cbor/builder.rb
index 7eb4bab2b..e2b9b46b1 100644
--- a/gems/smithy-cbor/lib/smithy-cbor/builder.rb
+++ b/gems/smithy-cbor/lib/smithy-cbor/builder.rb
@@ -13,21 +13,20 @@ def initialize(options = {})
       end
 
       def build(shape, data)
-        ref = shape.is_a?(MemberShape) ? shape : MemberShape.new(target: shape)
-        return if ref.target == Prelude::Unit
+        return if shape.target == Prelude::Unit
 
-        Cbor.encode(shape(ref, data))
+        Cbor.encode(serialize_shape(shape, data))
       end
 
       private
 
-      def shape(ref, value)
-        case ref.target
+      def serialize_shape(shape, value)
+        case shape.target
         when BlobShape then blob(value)
-        when ListShape then list(ref, value)
-        when MapShape then map(ref, value)
-        when StructureShape then structure(ref, value)
-        when UnionShape then union(ref, value)
+        when ListShape then list(shape, value)
+        when MapShape then map(shape, value)
+        when StructureShape then structure(shape, value)
+        when UnionShape then union(shape, value)
         else value
         end
       end
@@ -36,47 +35,45 @@ def blob(value)
         value.respond_to?(:read) ? value.read : value
       end
 
-      def list(ref, values)
+      def list(shape, values)
         return if values.nil?
 
-        shape = ref.target
         values.collect do |value|
-          shape(shape.member, value)
+          serialize_shape(shape.target.member, value)
         end
       end
 
-      def map(ref, values)
+      def map(shape, values)
         return if values.nil?
 
-        shape = ref.target
         values.each.with_object({}) do |(key, value), data|
-          data[key] = shape(shape.value, value)
+          data[key] = serialize_shape(shape.target.value, value)
         end
       end
 
-      def structure(ref, values)
+      def structure(shape, values)
         return if values.nil?
 
-        ref.target.members.each_with_object({}) do |(member_name, member_ref), data|
+        shape.target.members.each_with_object({}) do |(member_name, member_shape), data|
           value = values[member_name]
           next if value.nil?
 
-          data[member_ref.location_name] = shape(member_ref, value)
+          data[member_shape.location_name] = serialize_shape(member_shape, value)
         end
       end
 
-      def union(ref, values) # rubocop:disable Metrics/AbcSize
+      def union(shape, values) # rubocop:disable Metrics/AbcSize
         return if values.nil?
 
         data = {}
         if values.is_a?(Schema::Union)
-          _name, member_ref = ref.target.member_by_type(values.class)
-          data[member_ref.location_name] = shape(member_ref, values.value)
+          _name, member_shape = shape.target.member_by_type(values.class)
+          data[member_shape.location_name] = serialize_shape(member_shape, values.value)
         else
           key, value = values.first
-          if ref.target.member?(key)
-            member_ref = ref.target.member(key)
-            data[member_ref.location_name] = shape(member_ref, value)
+          if shape.target.member?(key)
+            member_shape = shape.target.member(key)
+            data[member_shape.location_name] = serialize_shape(member_shape, value)
           end
         end
         data
diff --git a/gems/smithy-cbor/lib/smithy-cbor/parser.rb b/gems/smithy-cbor/lib/smithy-cbor/parser.rb
index 2d580df76..1342df72a 100644
--- a/gems/smithy-cbor/lib/smithy-cbor/parser.rb
+++ b/gems/smithy-cbor/lib/smithy-cbor/parser.rb
@@ -12,68 +12,67 @@ def initialize(options = {})
         @options = options
       end
 
-      def parse(shape, bytes, target = nil)
+      def parse(shape, bytes, result = nil)
         return {} if bytes.empty?
 
-        ref = shape.is_a?(MemberShape) ? shape : MemberShape.new(target: shape)
-        shape(ref, Cbor.decode(bytes), target)
+        deserialize_shape(shape, Cbor.decode(bytes), result)
       end
 
       private
 
-      def shape(ref, value, target = nil)
+      def deserialize_shape(shape, value, result = nil)
         return nil if value.nil?
 
-        case ref.target
-        when ListShape then list(ref, value, target)
-        when MapShape then map(ref, value, target)
-        when StructureShape then structure(ref, value, target)
-        when UnionShape then union(ref, value, target)
+        case shape.target
+        when ListShape then list(shape, value, result)
+        when MapShape then map(shape, value, result)
+        when StructureShape then structure(shape, value, result)
+        when UnionShape then union(shape, value, result)
         else value
         end
       end
 
-      def list(ref, values, target = nil)
-        target = [] if target.nil?
+      def list(shape, values, result = nil)
+        result = [] if result.nil?
         values.each do |value|
-          next if value.nil? && !sparse?(ref.target)
+          next if value.nil? && !sparse?(shape.target)
 
-          target << shape(ref.target.member, value)
+          result << deserialize_shape(shape.target.member, value)
         end
-        target
+        result
       end
 
-      def map(ref, values, target = nil)
-        target = {} if target.nil?
+      def map(shape, values, result = nil)
+        result = {} if result.nil?
         values.each do |key, value|
-          next if value.nil? && !sparse?(ref.target)
+          next if value.nil? && !sparse?(shape.target)
 
-          target[key] = shape(ref.target.value, value)
+          result[key] = deserialize_shape(shape.target.value, value)
         end
-        target
+        result
       end
 
-      def structure(ref, values, target = nil)
-        target = ref.target.type.new if target.nil?
-        ref.target.members.each do |member_name, member_ref|
-          value = values[member_ref.location_name]
-          target[member_name] = shape(member_ref, value) unless value.nil?
+      def structure(shape, values, result = nil)
+        result = shape.target.type.new if result.nil?
+        shape.target.members.each do |member_name, member_shape|
+          value = values[member_shape.location_name]
+          result[member_name] = deserialize_shape(member_shape, value) unless value.nil?
         end
-        target
+        result
       end
 
-      def union(ref, values, target = nil) # rubocop:disable Metrics/AbcSize
-        ref.target.members.each do |member_name, member_ref|
-          value = values[member_ref.location_name]
+      def union(shape, values, result = nil) # rubocop:disable Metrics/AbcSize
+        shape.target.members.each do |member_name, member_shape|
+          value = values[member_shape.location_name]
           next if value.nil?
 
-          target = ref.target.member_type(member_name) if target.nil?
-          return target.new(member_name => shape(member_ref, value))
+          result = shape.target.member_type(member_name) if result.nil?
+          return result.new(member_name => deserialize_shape(member_shape, value))
         end
 
         values.delete('__type')
         key, value = values.first
-        ref.target.member_type(:unknown).new(unknown: { key => value })
+        shape.target.member_type(:unknown).new(unknown: { key => value })
       end
 
       def sparse?(shape)

From 68715943be277ec9ad4e5513eb9678c598c1703f Mon Sep 17 00:00:00 2001
From: Juli Tera <terajul@amazon.com>
Date: Thu, 4 Jun 2026 13:56:21 -0700
Subject: [PATCH 10/23] Refactor XML codec

---
 gems/smithy-xml/lib/smithy-xml/builder.rb     | 131 +++++++++---------
 gems/smithy-xml/lib/smithy-xml/doc_builder.rb |  20 +--
 gems/smithy-xml/lib/smithy-xml/parser.rb      |   9 +-
 .../smithy-xml/lib/smithy-xml/parser/frame.rb |  48 +++----
 .../smithy-xml/lib/smithy-xml/parser/stack.rb |   6 +-
 5 files changed, 108 insertions(+), 106 deletions(-)

diff --git a/gems/smithy-xml/lib/smithy-xml/builder.rb b/gems/smithy-xml/lib/smithy-xml/builder.rb
index c6935ad17..60de2b659 100644
--- a/gems/smithy-xml/lib/smithy-xml/builder.rb
+++ b/gems/smithy-xml/lib/smithy-xml/builder.rb
@@ -13,25 +13,24 @@ def initialize(options = {})
         @pad = options.fetch(:pad, '')
       end
 
-      def build(shape, data, target = nil)
-        ref = shape.is_a?(MemberShape) ? shape : MemberShape.new(target: shape)
-        target ||= []
-        @builder = DocBuilder.new(target: target, indent: @indent, pad: @pad)
-        structure(ref.location_name || ref.target.traits['smithy.api#xmlName'] || ref.target.name, ref, data)
-        target.join
+      def build(shape, data, output = nil)
+        output ||= []
+        @builder = DocBuilder.new(output: output, indent: @indent, pad: @pad)
+        structure(shape.target.traits['smithy.api#xmlName'] || shape.target.name, shape, data)
+        output.join
       end
 
       private
 
-      def shape(name, ref, value)
-        case ref.target
-        when BlobShape then node(name, ref, blob(value))
-        when ListShape then list(name, ref, value)
-        when MapShape then map(name, ref, value)
-        when StructureShape then structure(name, ref, value)
-        when TimestampShape then node(name, ref, timestamp(ref, value))
-        when UnionShape then union(name, ref, value)
-        else node(name, ref, value.to_s)
+      def serialize_shape(name, shape, value)
+        case shape.target
+        when BlobShape then node(name, shape, blob(value))
+        when ListShape then list(name, shape, value)
+        when MapShape then map(name, shape, value)
+        when StructureShape then structure(name, shape, value)
+        when TimestampShape then node(name, shape, timestamp(shape, value))
+        when UnionShape then union(name, shape, value)
+        else node(name, shape, value.to_s)
         end
       end
 
@@ -39,67 +38,71 @@ def blob(value)
         Base64.strict_encode64(value.respond_to?(:read) ? value.read : value)
       end
 
-      def list(name, ref, values)
-        member_ref = ref.target.member
-        if flat?(ref)
+      def list(name, shape, values)
+        member_shape = shape.target.member
+        if flat?(shape)
           values.each do |value|
-            shape(name, member_ref, value)
+            serialize_shape(name, member_shape, value)
           end
         else
-          node(name, ref) do
+          node(name, shape) do
             values.each do |value|
-              shape(location_name(member_ref, 'member'), ref.target.member, value)
+              serialize_shape(location_name(member_shape, 'member'), shape.target.member, value)
             end
           end
         end
       end
 
-      def map(name, ref, values) # rubocop:disable Metrics/AbcSize
-        key_ref = ref.target.key
-        value_ref = ref.target.value
-        if flat?(ref)
-          values.each do |key, value|
-            node(name, ref) do
-              shape(location_name(key_ref, 'key'), key_ref, key)
-              shape(location_name(value_ref, 'value'), value_ref, value)
-            end
-          end
+      def map(name, shape, values)
+        key_ref = shape.target.key
+        value_ref = shape.target.value
+        if flat?(shape)
+          resolve_flat(name, shape, values, key_ref, value_ref)
         else
-          node(name, ref) do
+          node(name, shape) do
             values.each do |key, value|
               node('entry', MemberShape.new(target: MapShape.new)) do
-                shape(location_name(key_ref, 'key'), key_ref, key)
-                shape(location_name(value_ref, 'value'), value_ref, value)
+                serialize_shape(location_name(key_ref, 'key'), key_ref, key)
+                serialize_shape(location_name(value_ref, 'value'), value_ref, value)
               end
             end
           end
         end
       end
 
-      def structure(name, ref, values)
-        return node(name, ref) if values.empty?
+      def resolve_flat(name, shape, values, key_ref, value_ref)
+        values.each do |key, value|
+          node(name, shape) do
+            serialize_shape(location_name(key_ref, 'key'), key_ref, key)
+            serialize_shape(location_name(value_ref, 'value'), value_ref, value)
+          end
+        end
+      end
+
+      def structure(name, shape, values)
+        return node(name, shape) if values.empty?
 
-        node(name, ref, structure_attrs(ref, values)) do
-          ref.target.members.each do |member_name, member_ref|
+        node(name, shape, structure_attrs(shape, values)) do
+          shape.target.members.each do |member_name, member_shape|
             next if values[member_name].nil?
-            next if xml_attribute?(member_ref)
+            next if xml_attribute?(member_shape)
 
-            shape(location_name(member_ref, member_ref.location_name), member_ref, values[member_name])
+            serialize_shape(location_name(member_shape, member_shape.location_name), member_shape, values[member_name])
           end
         end
       end
 
-      def structure_attrs(ref, values)
-        ref.target.members.each_with_object({}) do |(member_name, member_ref), attrs|
-          if xml_attribute?(member_ref) && values.key?(member_name)
-            attrs[location_name(member_ref, member_ref.location_name)] = values[member_name]
+      def structure_attrs(shape, values)
+        shape.target.members.each_with_object({}) do |(member_name, member_shape), attrs|
+          if xml_attribute?(member_shape) && values.key?(member_name)
+            attrs[location_name(member_shape, member_shape.location_name)] = values[member_name]
           end
         end
       end
 
-      def timestamp(ref, value)
+      def timestamp(shape, value)
         trait = 'smithy.api#timestampFormat'
-        case ref.traits[trait] || ref.target.traits[trait]
+        case shape.traits[trait] || shape.target.traits[trait]
         when 'epoch-seconds' then value.to_i.to_s
         when 'http-date' then value.utc.httpdate
         else
@@ -108,33 +111,33 @@ def timestamp(ref, value)
         end
       end
 
-      def union(name, ref, values) # rubocop:disable Metrics/AbcSize
-        return node(name, ref) if values.empty?
+      def union(name, shape, values) # rubocop:disable Metrics/AbcSize
+        return node(name, shape) if values.empty?
 
-        node(name, ref, structure_attrs(ref, values)) do
+        node(name, shape, structure_attrs(shape, values)) do
           if values.is_a?(Schema::Union)
-            _name, member_ref = ref.target.member_by_type(values.class)
-            shape(location_name(member_ref, member_ref.location_name), member_ref, values.value)
+            _name, member_shape = shape.target.member_by_type(values.class)
+            serialize_shape(location_name(member_shape, member_shape.location_name), member_shape, values.value)
           else
             key, value = values.first
-            if ref.target.member?(key)
-              member_ref = ref.target.member(key)
-              shape(location_name(member_ref, member_ref.location_name), member_ref, value)
+            if shape.target.member?(key)
+              member_shape = shape.target.member(key)
+              serialize_shape(location_name(member_shape, member_shape.location_name), member_shape, value)
             end
           end
         end
       end
 
-      def location_name(ref, default = nil)
-        ref.traits['smithy.api#xmlName'] || default
+      def location_name(shape, default = nil)
+        shape.traits['smithy.api#xmlName'] || default
       end
 
-      def flat?(ref)
-        ref.traits.key?('smithy.api#xmlFlattened')
+      def flat?(shape)
+        shape.traits.key?('smithy.api#xmlFlattened')
       end
 
-      def xml_attribute?(ref)
-        ref.traits.key?('smithy.api#xmlAttribute')
+      def xml_attribute?(shape)
+        shape.traits.key?('smithy.api#xmlAttribute')
       end
 
       # The `args` list may contain:
@@ -147,16 +150,16 @@ def xml_attribute?(ref)
       # Pass a block if you want to nest XML nodes inside.  When doing this,
       # you may *not* pass a value to the `args` list.
       #
-      def node(name, ref, *args, &)
+      def node(name, shape, *args, &)
         attrs = args.last.is_a?(Hash) ? args.pop : {}
-        attrs = shape_attrs(ref).merge(attrs)
+        attrs = shape_attrs(shape).merge(attrs)
         args << attrs
         @builder.node(name, *args, &)
       end
 
-      def shape_attrs(ref)
+      def shape_attrs(shape)
         trait = 'smithy.api#xmlNamespace'
-        xmlns = ref.traits[trait] || ref.target.traits[trait]
+        xmlns = shape.traits[trait] || shape.target.traits[trait]
         return {} unless xmlns
 
         if (prefix = xmlns['prefix'])
diff --git a/gems/smithy-xml/lib/smithy-xml/doc_builder.rb b/gems/smithy-xml/lib/smithy-xml/doc_builder.rb
index 0431dad29..e527a65db 100644
--- a/gems/smithy-xml/lib/smithy-xml/doc_builder.rb
+++ b/gems/smithy-xml/lib/smithy-xml/doc_builder.rb
@@ -4,18 +4,18 @@ module Smithy
   module Xml
     # @api private
     class DocBuilder
-      # @option options [#<<] :target ('')
+      # @option options [#<<] :output ('')
       # @option options [String] :pad ('')
       # @option options [String] :indent ('')
       def initialize(options = {})
-        # The String has to be mutable because @target implements `<<` method.
-        @target = options[:target] || String.new
+        # The String has to be mutable because @output implements `<<` method.
+        @output = options[:output] || String.new
         @indent = options[:indent] || ''
         @pad = options[:pad] || ''
         @end_of_line = @indent == '' ? '' : "\n"
       end
 
-      attr_reader :target
+      attr_reader :output
 
       # @overload node(name, attributes = {})
       #   Adds a self closing element without any content.
@@ -33,15 +33,15 @@ def initialize(options = {})
       def node(name, *args, &) # rubocop:disable Metrics/AbcSize
         attrs = args.last.is_a?(Hash) ? args.pop : {}
         if block_given?
-          @target << open_el(name, attrs)
-          @target << @end_of_line
+          @output << open_el(name, attrs)
+          @output << @end_of_line
           increase_pad(&)
-          @target << @pad
-          @target << close_el(name)
+          @output << @pad
+          @output << close_el(name)
         elsif args.empty?
-          @target << empty_element(name, attrs)
+          @output << empty_element(name, attrs)
         else
-          @target << inline_element(name, args.first, attrs)
+          @output << inline_element(name, args.first, attrs)
         end
       end
 
diff --git a/gems/smithy-xml/lib/smithy-xml/parser.rb b/gems/smithy-xml/lib/smithy-xml/parser.rb
index a48ddbc8f..1ad19893b 100644
--- a/gems/smithy-xml/lib/smithy-xml/parser.rb
+++ b/gems/smithy-xml/lib/smithy-xml/parser.rb
@@ -22,14 +22,13 @@ def initialize(options = {})
       # The purpose of the unhandled callback block is to allow callers to access values
       # such as a request ID that are part of the XML body but not part of modeling.
       #
-      # @param [MemberShape, Shape] shape
+      # @param [Shape] shape
       # @param [String] bytes
-      # @param [Object, nil] target (nil)
+      # @param [Object, nil] result (nil)
       # @return [Object]
-      def parse(shape, bytes, target = nil, &)
-        ref = shape.is_a?(MemberShape) ? shape : MemberShape.new(target: shape)
+      def parse(shape, bytes, result = nil, &)
         bytes = '<xml/>' if bytes.nil? || bytes.empty?
-        stack = Stack.new(ref, target, &)
+        stack = Stack.new(shape, result, &)
         @engine.new(stack).parse(bytes.to_s)
         stack.result
       end
diff --git a/gems/smithy-xml/lib/smithy-xml/parser/frame.rb b/gems/smithy-xml/lib/smithy-xml/parser/frame.rb
index da8d4dd18..b2a3709fe 100644
--- a/gems/smithy-xml/lib/smithy-xml/parser/frame.rb
+++ b/gems/smithy-xml/lib/smithy-xml/parser/frame.rb
@@ -12,10 +12,10 @@ class Frame
         include Smithy::Schema::Shapes
 
         class << self
-          def new(path, parent, ref, result = nil)
+          def new(path, parent, shape, result = nil)
             if self == Frame
-              frame = frame_class(ref).allocate
-              frame.send(:initialize, path, parent, ref, result)
+              frame = frame_class(shape).allocate
+              frame.send(:initialize, path, parent, shape, result)
               frame
             else
               super
@@ -24,11 +24,11 @@ def new(path, parent, ref, result = nil)
 
           private
 
-          def frame_class(ref)
-            klass = FRAME_CLASSES[ref.target.class]
-            if klass == ListFrame && ref.traits.key?('smithy.api#xmlFlattened')
+          def frame_class(shape)
+            klass = FRAME_CLASSES[shape.target.class]
+            if klass == ListFrame && shape.traits.key?('smithy.api#xmlFlattened')
               FlatListFrame
-            elsif klass == MapFrame && ref.traits.key?('smithy.api#xmlFlattened')
+            elsif klass == MapFrame && shape.traits.key?('smithy.api#xmlFlattened')
               MapEntryFrame
             else
               klass
@@ -36,15 +36,15 @@ def frame_class(ref)
           end
         end
 
-        def initialize(path, parent, ref, result)
+        def initialize(path, parent, shape, result)
           @path = path
           @parent = parent
-          @ref = ref
+          @shape = shape
           @result = result
           @text = []
         end
 
-        attr_reader :parent, :ref, :result
+        attr_reader :parent, :shape, :result
 
         def append_text(value)
           @text << value
@@ -103,7 +103,7 @@ def result
       class FlatListFrame < Frame
         def initialize(xml_name, *args)
           super
-          @member = Frame.new(xml_name, self, @ref.target.member)
+          @member = Frame.new(xml_name, self, @shape.target.member)
         end
 
         def result
@@ -147,7 +147,7 @@ class ListFrame < Frame
         def initialize(*args)
           super
           @result = []
-          @member_xml_name = @ref.target.member.traits['smithy.api#xmlName'] || 'member'
+          @member_xml_name = @shape.target.member.traits['smithy.api#xmlName'] || 'member'
         end
 
         def child_frame(xml_name)
@@ -155,7 +155,7 @@ def child_frame(xml_name)
             raise NotImplementedError, "Expected XML name '#{@member_xml_name}' for ListFrame, got '#{xml_name}'"
           end
 
-          Frame.new(xml_name, self, @ref.target.member)
+          Frame.new(xml_name, self, @shape.target.member)
         end
 
         def consume_child_frame(child)
@@ -167,10 +167,10 @@ def consume_child_frame(child)
       class MapEntryFrame < Frame
         def initialize(xml_name, *args)
           super
-          @key_name = @ref.target.key.traits['smithy.api#xmlName'] || 'key'
-          @key = Frame.new(xml_name, self, @ref.target.key)
-          @value_name = @ref.target.value.traits['smithy.api#xmlName'] || 'value'
-          @value = Frame.new(xml_name, self, @ref.target.value)
+          @key_name = @shape.target.key.traits['smithy.api#xmlName'] || 'key'
+          @key = Frame.new(xml_name, self, @shape.target.key)
+          @value_name = @shape.target.value.traits['smithy.api#xmlName'] || 'value'
+          @value = Frame.new(xml_name, self, @shape.target.value)
         end
 
         # @return [StringFrame]
@@ -202,7 +202,7 @@ def child_frame(xml_name)
             raise NotImplementedError, "Expected XML name 'entry' for MapFrame, got '#{xml_name}'"
           end
 
-          MapEntryFrame.new(xml_name, self, @ref)
+          MapEntryFrame.new(xml_name, self, @shape)
         end
 
         def consume_child_frame(child)
@@ -231,19 +231,19 @@ def result
 
       # @api private
       class StructureFrame < Frame
-        def initialize(xml_name, parent, ref, result = nil)
+        def initialize(xml_name, parent, shape, result = nil)
           super
           @members = {}
-          ref.target.members.each do |member_name, member_ref|
+          shape.target.members.each do |member_name, member_ref|
             @members[xml_name(member_ref)] = { name: member_name, ref: member_ref }
           end
-          @result ||= ref.target.type.new
+          @result ||= shape.target.type.new
         end
 
         def child_frame(xml_name)
           if (@member = @members[xml_name])
             Frame.new(xml_name, self, @member[:ref])
-          elsif @ref.target.is_a?(UnionShape)
+          elsif @shape.target.is_a?(UnionShape)
             UnknownMemberFrame.new(xml_name, self, nil, @result)
           else
             NullFrame.new(xml_name, self)
@@ -267,8 +267,8 @@ def consume_child_frame(child) # rubocop:disable Metrics/AbcSize
 
         private
 
-        def xml_name(ref)
-          ref.traits['smithy.api#xmlName'] || ref.location_name
+        def xml_name(shape)
+          shape.traits['smithy.api#xmlName'] || shape.location_name
         end
       end
 
diff --git a/gems/smithy-xml/lib/smithy-xml/parser/stack.rb b/gems/smithy-xml/lib/smithy-xml/parser/stack.rb
index 00d1a8601..97f45614b 100644
--- a/gems/smithy-xml/lib/smithy-xml/parser/stack.rb
+++ b/gems/smithy-xml/lib/smithy-xml/parser/stack.rb
@@ -7,8 +7,8 @@ module Xml
     class Parser
       # @api private
       class Stack
-        def initialize(ref, result = nil, &unhandled_callback)
-          @ref = ref
+        def initialize(shape, result = nil, &unhandled_callback)
+          @shape = shape
           @result = result
           @unhandled_callback = unhandled_callback
           @frame = self
@@ -51,7 +51,7 @@ def error(msg, line = nil, column = nil)
         end
 
         def child_frame(name)
-          Frame.new(name, self, @ref, @result)
+          Frame.new(name, self, @shape, @result)
         end
 
         def consume_child_frame(frame)

From 1433a9316993242e8d2ab97f047b184ea0b25d41 Mon Sep 17 00:00:00 2001
From: Juli Tera <terajul@amazon.com>
Date: Thu, 4 Jun 2026 16:59:00 -0700
Subject: [PATCH 11/23] Follow-up fixes

---
 gems/smithy-schema/lib/smithy-schema/shapes.rb | 6 ++++--
 gems/smithy-xml/lib/smithy-xml/parser/frame.rb | 6 +++---
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/gems/smithy-schema/lib/smithy-schema/shapes.rb b/gems/smithy-schema/lib/smithy-schema/shapes.rb
index 5431260f3..8c3a11c4c 100644
--- a/gems/smithy-schema/lib/smithy-schema/shapes.rb
+++ b/gems/smithy-schema/lib/smithy-schema/shapes.rb
@@ -14,6 +14,8 @@ def initialize(options = {})
           @target = self
         end
 
+        # @return [Shape] Returns self, so a bare shape can be traversed
+        #   uniformly with a {MemberShape} via +#target+.
         attr_reader :target
 
         # @return [String] Absolute shape ID from model
@@ -126,10 +128,10 @@ def initialize(options = {})
         # @return [String]
         attr_accessor :name
 
-        # @return [MemberShape]
+        # @return [Shape]
         attr_accessor :input
 
-        # @return [MemberShape]
+        # @return [Shape]
         attr_accessor :output
 
         # @return [Array<MemberShape>]
diff --git a/gems/smithy-xml/lib/smithy-xml/parser/frame.rb b/gems/smithy-xml/lib/smithy-xml/parser/frame.rb
index b2a3709fe..20ce64a74 100644
--- a/gems/smithy-xml/lib/smithy-xml/parser/frame.rb
+++ b/gems/smithy-xml/lib/smithy-xml/parser/frame.rb
@@ -234,15 +234,15 @@ class StructureFrame < Frame
         def initialize(xml_name, parent, shape, result = nil)
           super
           @members = {}
-          shape.target.members.each do |member_name, member_ref|
-            @members[xml_name(member_ref)] = { name: member_name, ref: member_ref }
+          shape.target.members.each do |member_name, member_shape|
+            @members[xml_name(member_shape)] = { name: member_name, shape: member_shape }
           end
           @result ||= shape.target.type.new
         end
 
         def child_frame(xml_name)
           if (@member = @members[xml_name])
-            Frame.new(xml_name, self, @member[:ref])
+            Frame.new(xml_name, self, @member[:shape])
           elsif @shape.target.is_a?(UnionShape)
             UnknownMemberFrame.new(xml_name, self, nil, @result)
           else

From 80d31005d4dd851b87f6d292c2867c856410fc8c Mon Sep 17 00:00:00 2001
From: Juli Tera <terajul@amazon.com>
Date: Thu, 4 Jun 2026 17:01:51 -0700
Subject: [PATCH 12/23] Fix RBS

---
 gems/smithy-schema/sig/smithy-schema/shapes.rbs | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/gems/smithy-schema/sig/smithy-schema/shapes.rbs b/gems/smithy-schema/sig/smithy-schema/shapes.rbs
index d1fe31fc9..f28c3b7e9 100644
--- a/gems/smithy-schema/sig/smithy-schema/shapes.rbs
+++ b/gems/smithy-schema/sig/smithy-schema/shapes.rbs
@@ -4,6 +4,7 @@ module Smithy
       class Shape
         def initialize: (?Hash[Symbol, untyped]) ?{ (self) -> void } -> void
 
+        attr_reader target: Shape
         attr_accessor id: String
         attr_accessor name: String
         attr_accessor traits: Hash[String, untyped]
@@ -33,8 +34,8 @@ module Smithy
 
       class OperationShape < Shape
         attr_accessor name: String
-        attr_accessor input: MemberShape
-        attr_accessor output: MemberShape
+        attr_accessor input: Shape
+        attr_accessor output: Shape
         attr_accessor errors: Array[MemberShape]
       end
 

From a64909f515da7092dd3393cd578225d6c160cee7 Mon Sep 17 00:00:00 2001
From: Juli Tera <terajul@amazon.com>
Date: Thu, 4 Jun 2026 17:33:12 -0700
Subject: [PATCH 13/23] Rename codec dispatch methods

---
 gems/smithy-cbor/lib/smithy-cbor/builder.rb | 14 +++++++-------
 gems/smithy-cbor/lib/smithy-cbor/parser.rb  | 12 ++++++------
 gems/smithy-json/lib/smithy-json/builder.rb | 14 +++++++-------
 gems/smithy-json/lib/smithy-json/parser.rb  | 12 ++++++------
 gems/smithy-xml/lib/smithy-xml/builder.rb   | 20 ++++++++++----------
 5 files changed, 36 insertions(+), 36 deletions(-)

diff --git a/gems/smithy-cbor/lib/smithy-cbor/builder.rb b/gems/smithy-cbor/lib/smithy-cbor/builder.rb
index e2b9b46b1..08c427d87 100644
--- a/gems/smithy-cbor/lib/smithy-cbor/builder.rb
+++ b/gems/smithy-cbor/lib/smithy-cbor/builder.rb
@@ -15,12 +15,12 @@ def initialize(options = {})
       def build(shape, data)
         return if shape.target == Prelude::Unit
 
-        Cbor.encode(serialize_shape(shape, data))
+        Cbor.encode(build_shape(shape, data))
       end
 
       private
 
-      def serialize_shape(shape, value)
+      def build_shape(shape, value)
         case shape.target
         when BlobShape then blob(value)
         when ListShape then list(shape, value)
@@ -39,7 +39,7 @@ def list(shape, values)
         return if values.nil?
 
         values.collect do |value|
-          serialize_shape(shape.target.member, value)
+          build_shape(shape.target.member, value)
         end
       end
 
@@ -47,7 +47,7 @@ def map(shape, values)
         return if values.nil?
 
         values.each.with_object({}) do |(key, value), data|
-          data[key] = serialize_shape(shape.target.value, value)
+          data[key] = build_shape(shape.target.value, value)
         end
       end
 
@@ -58,7 +58,7 @@ def structure(shape, values)
           value = values[member_name]
           next if value.nil?
 
-          data[member_shape.location_name] = serialize_shape(member_shape, value)
+          data[member_shape.location_name] = build_shape(member_shape, value)
         end
       end
 
@@ -68,12 +68,12 @@ def union(shape, values) # rubocop:disable Metrics/AbcSize
         data = {}
         if values.is_a?(Schema::Union)
           _name, member_shape = shape.target.member_by_type(values.class)
-          data[member_shape.location_name] = serialize_shape(member_shape, values.value)
+          data[member_shape.location_name] = build_shape(member_shape, values.value)
         else
           key, value = values.first
           if shape.target.member?(key)
             member_shape = shape.target.member(key)
-            data[member_shape.location_name] = serialize_shape(member_shape, value)
+            data[member_shape.location_name] = build_shape(member_shape, value)
           end
         end
         data
diff --git a/gems/smithy-cbor/lib/smithy-cbor/parser.rb b/gems/smithy-cbor/lib/smithy-cbor/parser.rb
index 1342df72a..35d4fc78e 100644
--- a/gems/smithy-cbor/lib/smithy-cbor/parser.rb
+++ b/gems/smithy-cbor/lib/smithy-cbor/parser.rb
@@ -15,12 +15,12 @@ def initialize(options = {})
       def parse(shape, bytes, result = nil)
         return {} if bytes.empty?
 
-        deserialize_shape(shape, Cbor.decode(bytes), result)
+        parse_shape(shape, Cbor.decode(bytes), result)
       end
 
       private
 
-      def deserialize_shape(shape, value, result = nil)
+      def parse_shape(shape, value, result = nil)
         return nil if value.nil?
 
         case shape.target
@@ -37,7 +37,7 @@ def list(shape, values, result = nil)
         values.each do |value|
           next if value.nil? && !sparse?(shape.target)
 
-          result << deserialize_shape(shape.target.member, value)
+          result << parse_shape(shape.target.member, value)
         end
         result
       end
@@ -47,7 +47,7 @@ def map(shape, values, result = nil)
         values.each do |key, value|
           next if value.nil? && !sparse?(shape.target)
 
-          result[key] = deserialize_shape(shape.target.value, value)
+          result[key] = parse_shape(shape.target.value, value)
         end
         result
       end
@@ -56,7 +56,7 @@ def structure(shape, values, result = nil)
         result = shape.target.type.new if result.nil?
         shape.target.members.each do |member_name, member_shape|
           value = values[member_shape.location_name]
-          result[member_name] = deserialize_shape(member_shape, value) unless value.nil?
+          result[member_name] = parse_shape(member_shape, value) unless value.nil?
         end
         result
       end
@@ -67,7 +67,7 @@ def union(shape, values, result = nil) # rubocop:disable Metrics/AbcSize
           next if value.nil?
 
           result = shape.target.member_type(member_name) if result.nil?
-          return result.new(member_name => deserialize_shape(member_shape, value))
+          return result.new(member_name => parse_shape(member_shape, value))
         end
 
         values.delete('__type')
diff --git a/gems/smithy-json/lib/smithy-json/builder.rb b/gems/smithy-json/lib/smithy-json/builder.rb
index 9095fe04f..7edf9677a 100644
--- a/gems/smithy-json/lib/smithy-json/builder.rb
+++ b/gems/smithy-json/lib/smithy-json/builder.rb
@@ -13,12 +13,12 @@ def initialize(options = {})
       end
 
       def build(shape, data)
-        Smithy::Json.dump(serialize_shape(shape, data))
+        Smithy::Json.dump(build_shape(shape, data))
       end
 
       private
 
-      def serialize_shape(shape, value) # rubocop:disable Metrics/CyclomaticComplexity
+      def build_shape(shape, value) # rubocop:disable Metrics/CyclomaticComplexity
         case shape.target
         when BlobShape then blob(value)
         when FloatShape then float(value)
@@ -51,7 +51,7 @@ def list(shape, values)
         return if values.nil?
 
         values.collect do |value|
-          serialize_shape(shape.target.member, value)
+          build_shape(shape.target.member, value)
         end
       end
 
@@ -59,7 +59,7 @@ def map(shape, values)
         return if values.nil?
 
         values.each.with_object({}) do |(key, value), data|
-          data[key] = serialize_shape(shape.target.value, value)
+          data[key] = build_shape(shape.target.value, value)
         end
       end
 
@@ -68,7 +68,7 @@ def structure(shape, values)
 
         shape.target.members.each_with_object({}) do |(member_name, member_shape), data|
           value = values[member_name]
-          data[location_name(member_shape)] = serialize_shape(member_shape, value) unless value.nil?
+          data[location_name(member_shape)] = build_shape(member_shape, value) unless value.nil?
         end
       end
 
@@ -89,12 +89,12 @@ def union(shape, values) # rubocop:disable Metrics/AbcSize
         data = {}
         if values.is_a?(Schema::Union)
           _name, member_ref = shape.target.member_by_type(values.class)
-          data[location_name(member_ref)] = serialize_shape(member_ref, values.value)
+          data[location_name(member_ref)] = build_shape(member_ref, values.value)
         else
           key, value = values.first
           if shape.target.member?(key)
             member_ref = shape.target.member(key)
-            data[location_name(member_ref)] = serialize_shape(member_ref, value)
+            data[location_name(member_ref)] = build_shape(member_ref, value)
           end
         end
         data
diff --git a/gems/smithy-json/lib/smithy-json/parser.rb b/gems/smithy-json/lib/smithy-json/parser.rb
index 5aa5b893c..e2a251610 100644
--- a/gems/smithy-json/lib/smithy-json/parser.rb
+++ b/gems/smithy-json/lib/smithy-json/parser.rb
@@ -15,12 +15,12 @@ def initialize(options = {})
       def parse(shape, bytes, result = nil)
         return {} if bytes.empty?
 
-        deserialize_shape(shape, Smithy::Json.load(bytes), result)
+        parse_shape(shape, Smithy::Json.load(bytes), result)
       end
 
       private
 
-      def deserialize_shape(shape, value, result = nil) # rubocop:disable Metrics/CyclomaticComplexity
+      def parse_shape(shape, value, result = nil) # rubocop:disable Metrics/CyclomaticComplexity
         case shape.target
         when BlobShape then Base64.decode64(value)
         when FloatShape then float(value)
@@ -49,7 +49,7 @@ def list(shape, values, result = nil)
         values.each do |value|
           next if value.nil? && !sparse?(shape.target)
 
-          result << deserialize_shape(shape.target.member, value)
+          result << parse_shape(shape.target.member, value)
         end
         result
       end
@@ -59,7 +59,7 @@ def map(shape, values, result = nil)
         values.each do |key, value|
           next if value.nil? && !sparse?(shape.target)
 
-          result[key] = deserialize_shape(shape.target.value, value)
+          result[key] = parse_shape(shape.target.value, value)
         end
         result
       end
@@ -70,7 +70,7 @@ def structure(shape, values, result = nil)
         result = shape.target.type.new if result.nil?
         shape.target.members.each do |member_name, member_shape|
           value = values[location_name(member_shape)]
-          result[member_name] = deserialize_shape(member_shape, value) unless value.nil?
+          result[member_name] = parse_shape(member_shape, value) unless value.nil?
         end
         result
       end
@@ -94,7 +94,7 @@ def union(shape, values, result = nil) # rubocop:disable Metrics/AbcSize
           next if value.nil?
 
           result = shape.target.member_type(member_name) if result.nil?
-          return result.new(member_name => deserialize_shape(member_shape, value))
+          return result.new(member_name => parse_shape(member_shape, value))
         end
 
         values.delete('__type')
diff --git a/gems/smithy-xml/lib/smithy-xml/builder.rb b/gems/smithy-xml/lib/smithy-xml/builder.rb
index 60de2b659..83d1f87a4 100644
--- a/gems/smithy-xml/lib/smithy-xml/builder.rb
+++ b/gems/smithy-xml/lib/smithy-xml/builder.rb
@@ -22,7 +22,7 @@ def build(shape, data, output = nil)
 
       private
 
-      def serialize_shape(name, shape, value)
+      def build_shape(name, shape, value)
         case shape.target
         when BlobShape then node(name, shape, blob(value))
         when ListShape then list(name, shape, value)
@@ -42,12 +42,12 @@ def list(name, shape, values)
         member_shape = shape.target.member
         if flat?(shape)
           values.each do |value|
-            serialize_shape(name, member_shape, value)
+            build_shape(name, member_shape, value)
           end
         else
           node(name, shape) do
             values.each do |value|
-              serialize_shape(location_name(member_shape, 'member'), shape.target.member, value)
+              build_shape(location_name(member_shape, 'member'), shape.target.member, value)
             end
           end
         end
@@ -62,8 +62,8 @@ def map(name, shape, values)
           node(name, shape) do
             values.each do |key, value|
               node('entry', MemberShape.new(target: MapShape.new)) do
-                serialize_shape(location_name(key_ref, 'key'), key_ref, key)
-                serialize_shape(location_name(value_ref, 'value'), value_ref, value)
+                build_shape(location_name(key_ref, 'key'), key_ref, key)
+                build_shape(location_name(value_ref, 'value'), value_ref, value)
               end
             end
           end
@@ -73,8 +73,8 @@ def map(name, shape, values)
       def resolve_flat(name, shape, values, key_ref, value_ref)
         values.each do |key, value|
           node(name, shape) do
-            serialize_shape(location_name(key_ref, 'key'), key_ref, key)
-            serialize_shape(location_name(value_ref, 'value'), value_ref, value)
+            build_shape(location_name(key_ref, 'key'), key_ref, key)
+            build_shape(location_name(value_ref, 'value'), value_ref, value)
           end
         end
       end
@@ -87,7 +87,7 @@ def structure(name, shape, values)
             next if values[member_name].nil?
             next if xml_attribute?(member_shape)
 
-            serialize_shape(location_name(member_shape, member_shape.location_name), member_shape, values[member_name])
+            build_shape(location_name(member_shape, member_shape.location_name), member_shape, values[member_name])
           end
         end
       end
@@ -117,12 +117,12 @@ def union(name, shape, values) # rubocop:disable Metrics/AbcSize
         node(name, shape, structure_attrs(shape, values)) do
           if values.is_a?(Schema::Union)
             _name, member_shape = shape.target.member_by_type(values.class)
-            serialize_shape(location_name(member_shape, member_shape.location_name), member_shape, values.value)
+            build_shape(location_name(member_shape, member_shape.location_name), member_shape, values.value)
           else
             key, value = values.first
             if shape.target.member?(key)
               member_shape = shape.target.member(key)
-              serialize_shape(location_name(member_shape, member_shape.location_name), member_shape, value)
+              build_shape(location_name(member_shape, member_shape.location_name), member_shape, value)
             end
           end
         end

From cab41be43ce18b8c866c3f9d170262518d5f3a4f Mon Sep 17 00:00:00 2001
From: Juli Tera <terajul@amazon.com>
Date: Thu, 4 Jun 2026 17:33:18 -0700
Subject: [PATCH 14/23] Update codec documentation

---
 gems/smithy-cbor/lib/smithy-cbor/codec.rb | 10 +++++-----
 gems/smithy-json/lib/smithy-json/codec.rb | 10 +++++-----
 gems/smithy-xml/lib/smithy-xml/codec.rb   | 16 ++++++++--------
 3 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/gems/smithy-cbor/lib/smithy-cbor/codec.rb b/gems/smithy-cbor/lib/smithy-cbor/codec.rb
index 1931e6c64..2c95508e0 100644
--- a/gems/smithy-cbor/lib/smithy-cbor/codec.rb
+++ b/gems/smithy-cbor/lib/smithy-cbor/codec.rb
@@ -9,19 +9,19 @@ def initialize(options = {})
         @options = options
       end
 
-      # @param [MemberShape, Shape] shape
+      # @param [Shape] shape
       # @param [Object] data
       # @return [String, nil]
       def build(shape, data)
         Builder.new(@options).build(shape, data)
       end
 
-      # @param [MemberShape, Shape] shape
+      # @param [Shape] shape
       # @param [String] bytes
-      # @param [Object, nil] target (nil)
+      # @param [Object, nil] result (nil)
       # @return [Object, nil]
-      def parse(shape, bytes, target = nil)
-        Parser.new(@options).parse(shape, bytes, target)
+      def parse(shape, bytes, result = nil)
+        Parser.new(@options).parse(shape, bytes, result)
       end
     end
   end
diff --git a/gems/smithy-json/lib/smithy-json/codec.rb b/gems/smithy-json/lib/smithy-json/codec.rb
index c808dfc4a..0ad2c6d3c 100644
--- a/gems/smithy-json/lib/smithy-json/codec.rb
+++ b/gems/smithy-json/lib/smithy-json/codec.rb
@@ -9,19 +9,19 @@ def initialize(options = {})
         @options = options
       end
 
-      # @param [MemberShape, Shape] shape
+      # @param [Shape] shape
       # @param [Object] data
       # @return [String, nil]
       def build(shape, data)
         Builder.new(@options).build(shape, data)
       end
 
-      # @param [MemberShape, Shape] shape
+      # @param [Shape] shape
       # @param [String] bytes
-      # @param [Object, nil] target (nil)
+      # @param [Object, nil] result (nil)
       # @return [Object, nil]
-      def parse(shape, bytes, target = nil)
-        Parser.new(@options).parse(shape, bytes, target)
+      def parse(shape, bytes, result = nil)
+        Parser.new(@options).parse(shape, bytes, result)
       end
     end
   end
diff --git a/gems/smithy-xml/lib/smithy-xml/codec.rb b/gems/smithy-xml/lib/smithy-xml/codec.rb
index aede627ed..23ae8d86e 100644
--- a/gems/smithy-xml/lib/smithy-xml/codec.rb
+++ b/gems/smithy-xml/lib/smithy-xml/codec.rb
@@ -9,20 +9,20 @@ def initialize(options = {})
         @options = options
       end
 
-      # @param [MemberShape, Shape] shape
+      # @param [Shape] shape
       # @param [Object] data
-      # @param [String, nil] target (nil)
+      # @param [Array, nil] output (nil)
       # @return [String, nil]
-      def build(shape, data, target = nil)
-        Builder.new(@options).build(shape, data, target)
+      def build(shape, data, output = nil)
+        Builder.new(@options).build(shape, data, output)
       end
 
-      # @param [MemberShape, Shape] shape
+      # @param [Shape] shape
       # @param [String] bytes
-      # @param [Object, nil] target (nil)
+      # @param [Object, nil] result (nil)
       # @return [Object, nil]
-      def parse(shape, bytes, target = nil)
-        Parser.new(@options).parse(shape, bytes, target)
+      def parse(shape, bytes, result = nil)
+        Parser.new(@options).parse(shape, bytes, result)
       end
     end
   end

From 74ee26dd7409be1d045a1bb0d3bc1efed4c08d3d Mon Sep 17 00:00:00 2001
From: Juli Tera <terajul@amazon.com>
Date: Thu, 4 Jun 2026 17:33:34 -0700
Subject: [PATCH 15/23] Unwrap operation errors

---
 .../lib/smithy-client/plugins/transfer_encoding.rb        | 2 +-
 .../lib/smithy-client/rpc_v2_cbor/error_handler.rb        | 8 ++++----
 gems/smithy/lib/smithy/templates/client/schema.erb        | 2 +-
 gems/smithy/lib/smithy/views/client/schema.rb             | 2 +-
 projections/weather/lib/weather/schema.rb                 | 2 +-
 5 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/gems/smithy-client/lib/smithy-client/plugins/transfer_encoding.rb b/gems/smithy-client/lib/smithy-client/plugins/transfer_encoding.rb
index 823bcdca8..389ec9486 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/transfer_encoding.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/transfer_encoding.rb
@@ -29,7 +29,7 @@ def apply_transfer_encoding(context, payload)
           end
 
           def streaming_member_ref(context)
-            context.operation.input.target.members.detect do |_, ref|
+            context.operation.input.members.detect do |_, ref|
               ref.target.traits.key?('smithy.api#streaming')
             end&.last
           end
diff --git a/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/error_handler.rb b/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/error_handler.rb
index 1da335e68..af1ceda03 100644
--- a/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/error_handler.rb
+++ b/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/error_handler.rb
@@ -41,16 +41,16 @@ def extract_error(body, context)
           code = error_code(context, data)
           data = parse_error_data(context, body, code)
           [code, data]
-        rescue Cbor::Error
+        rescue Cbor::ParseError
           [http_status_error_code(context), Schema::EmptyStructure.new]
         end
 
         def parse_error_data(context, body, code)
           data = Schema::EmptyStructure.new
-          context.operation.errors.each do |ref|
-            next unless ref.target.name == code
+          context.operation.errors.each do |err_shape|
+            next unless err_shape.name == code
 
-            data = Cbor::Parser.new.parse(ref, body, ref.target.type.new)
+            data = Cbor::Parser.new.parse(err_shape, body, err_shape.type.new)
           end
           data
         end
diff --git a/gems/smithy/lib/smithy/templates/client/schema.erb b/gems/smithy/lib/smithy/templates/client/schema.erb
index e4dd12b03..d58a65ea3 100644
--- a/gems/smithy/lib/smithy/templates/client/schema.erb
+++ b/gems/smithy/lib/smithy/templates/client/schema.erb
@@ -53,7 +53,7 @@ module <%= module_name %>
         operation.input = <%= shape.input %>
         operation.output = <%= shape.output %>
 <% shape.errors.each do |error| -%>
-        operation.errors << <%= error.initializer %>
+        operation.errors << <%= error %>
 <% end -%>
         operation.traits = <%= shape.traits %>
 <% if !schema_gem? && shape.paginated? -%>
diff --git a/gems/smithy/lib/smithy/views/client/schema.rb b/gems/smithy/lib/smithy/views/client/schema.rb
index 56ff386d4..2e286949f 100644
--- a/gems/smithy/lib/smithy/views/client/schema.rb
+++ b/gems/smithy/lib/smithy/views/client/schema.rb
@@ -170,7 +170,7 @@ def paginator
 
           def build_errors(errors)
             errors = Set.new(@service.fetch('errors', [])).merge(errors)
-            errors.map { |error| MemberShape.new(@service, nil, error) }
+            errors.map { |error| shape_name_from_id(error['target']) }
           end
         end
 
diff --git a/projections/weather/lib/weather/schema.rb b/projections/weather/lib/weather/schema.rb
index 7eff0acd0..2c0934b1f 100644
--- a/projections/weather/lib/weather/schema.rb
+++ b/projections/weather/lib/weather/schema.rb
@@ -56,7 +56,7 @@ module Schema
         operation.name = "GetCity"
         operation.input = GetCityInput
         operation.output = GetCityOutput
-        operation.errors << ::Smithy::Schema::Shapes::MemberShape.new(target: NoSuchResource)
+        operation.errors << NoSuchResource
         operation.traits = {"smithy.api#readonly" => {}}
       end)
       service.add_operation(:get_current_time, ::Smithy::Schema::Shapes::OperationShape.new do |operation|

From de790970fa03a0345d550c6cb9bd99c5dd183811 Mon Sep 17 00:00:00 2001
From: Juli Tera <terajul@amazon.com>
Date: Thu, 4 Jun 2026 17:33:42 -0700
Subject: [PATCH 16/23] Update RBS for unwrapped shapes

---
 gems/smithy-schema/lib/smithy-schema/shapes.rb  | 2 +-
 gems/smithy-schema/sig/smithy-schema/shapes.rbs | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/gems/smithy-schema/lib/smithy-schema/shapes.rb b/gems/smithy-schema/lib/smithy-schema/shapes.rb
index 8c3a11c4c..9b832132c 100644
--- a/gems/smithy-schema/lib/smithy-schema/shapes.rb
+++ b/gems/smithy-schema/lib/smithy-schema/shapes.rb
@@ -134,7 +134,7 @@ def initialize(options = {})
         # @return [Shape]
         attr_accessor :output
 
-        # @return [Array<MemberShape>]
+        # @return [Array<Shape>]
         attr_accessor :errors
       end
 
diff --git a/gems/smithy-schema/sig/smithy-schema/shapes.rbs b/gems/smithy-schema/sig/smithy-schema/shapes.rbs
index f28c3b7e9..ea7a332a4 100644
--- a/gems/smithy-schema/sig/smithy-schema/shapes.rbs
+++ b/gems/smithy-schema/sig/smithy-schema/shapes.rbs
@@ -36,7 +36,7 @@ module Smithy
         attr_accessor name: String
         attr_accessor input: Shape
         attr_accessor output: Shape
-        attr_accessor errors: Array[MemberShape]
+        attr_accessor errors: Array[Shape]
       end
 
       class BigDecimalShape < Shape

From b2fee547c12ba0fb5f3ee4e64699cc5cb82004ce Mon Sep 17 00:00:00 2001
From: Juli Tera <terajul@amazon.com>
Date: Fri, 5 Jun 2026 08:16:58 -0700
Subject: [PATCH 17/23] Clean up codec RBS

---
 gems/smithy-cbor/sig/smithy-cbor/codec.rbs | 4 ++--
 gems/smithy-json/sig/smithy-json/codec.rbs | 4 ++--
 gems/smithy-xml/sig/smithy-xml/codec.rbs   | 4 ++--
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/gems/smithy-cbor/sig/smithy-cbor/codec.rbs b/gems/smithy-cbor/sig/smithy-cbor/codec.rbs
index 2b6341287..261cc3410 100644
--- a/gems/smithy-cbor/sig/smithy-cbor/codec.rbs
+++ b/gems/smithy-cbor/sig/smithy-cbor/codec.rbs
@@ -2,8 +2,8 @@ module Smithy
   module Cbor
     module Codec
       def initialize: (?Hash[Symbol, untyped] options) -> void
-      def build: (Schema::Shapes::Shape | Schema::Shapes::MemberShape shape, Object data) -> (nil | String)
-      def parse: (Schema::Shapes::Shape | Schema::Shapes::MemberShape shape, String bytes, ?Object ?target) -> Object?
+      def build: (Schema::Shapes::Shape shape, Object data) -> (nil | String)
+      def parse: (Schema::Shapes::Shape shape, String bytes, ?Object ?result) -> Object?
     end
   end
 end
\ No newline at end of file
diff --git a/gems/smithy-json/sig/smithy-json/codec.rbs b/gems/smithy-json/sig/smithy-json/codec.rbs
index 5d55bff0f..9a6249ca7 100644
--- a/gems/smithy-json/sig/smithy-json/codec.rbs
+++ b/gems/smithy-json/sig/smithy-json/codec.rbs
@@ -2,8 +2,8 @@ module Smithy
   module Json
     class Codec
       def initialize: (?Hash[Symbol, untyped] options) -> void
-      def build: (Schema::Shapes::Shape | Schema::Shapes::MemberShape shape, Object data) -> (nil | String)
-      def parse: (Schema::Shapes::Shape | Schema::Shapes::MemberShape shape, String bytes, ?Object ?target) -> Object?
+      def build: (Schema::Shapes::Shape shape, Object data) -> (nil | String)
+      def parse: (Schema::Shapes::Shape shape, String bytes, ?Object ?result) -> Object?
     end
   end
 end
\ No newline at end of file
diff --git a/gems/smithy-xml/sig/smithy-xml/codec.rbs b/gems/smithy-xml/sig/smithy-xml/codec.rbs
index 5768e40d6..638f8bbca 100644
--- a/gems/smithy-xml/sig/smithy-xml/codec.rbs
+++ b/gems/smithy-xml/sig/smithy-xml/codec.rbs
@@ -1,8 +1,8 @@
 module Smithy
   module Xml
     class Codec
-      def build: (Schema::Shapes::Shape | Schema::Shapes::MemberShape shape, Object data) -> (nil | String)
-      def parse: (Schema::Shapes::Shape | Schema::Shapes::MemberShape shape, String bytes, ?Object ?target) -> Object?
+      def build: (Schema::Shapes::Shape shape, Object data, ?Array? output) -> (nil | String)
+      def parse: (Schema::Shapes::Shape shape, String bytes, ?Object ?result) -> Object?
     end
   end
 end
\ No newline at end of file

From bfc5302710e929b2d19d56bc2959647ab37bf418 Mon Sep 17 00:00:00 2001
From: Juli Tera <terajul@amazon.com>
Date: Fri, 5 Jun 2026 08:49:59 -0700
Subject: [PATCH 18/23] Update plugin and handler shape references

---
 .../lib/smithy-client/plugins/host_prefix.rb  |  6 +--
 .../plugins/idempotency_token.rb              |  4 +-
 .../plugins/request_compression.rb            |  6 +--
 .../plugins/transfer_encoding.rb              | 18 ++++----
 .../lib/smithy-client/rpc_v2_cbor/handler.rb  |  8 ++--
 .../smithy-client/stubbing/data_applicator.rb | 36 +++++++--------
 .../lib/smithy-client/stubbing/empty_stub.rb  | 44 +++++++++----------
 .../plugins/transfer_encoding_spec.rb         |  4 +-
 .../spec/smithy-xml/builder_spec.rb           |  4 +-
 9 files changed, 65 insertions(+), 65 deletions(-)

diff --git a/gems/smithy-client/lib/smithy-client/plugins/host_prefix.rb b/gems/smithy-client/lib/smithy-client/plugins/host_prefix.rb
index 769cae103..536f5932d 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/host_prefix.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/host_prefix.rb
@@ -51,9 +51,9 @@ def apply_host_prefix(context, host_prefix)
 
           def label_value(input, label, params)
             name = nil
-            input.target.members.each do |member_name, member_ref|
-              next unless member_ref.traits.key?('smithy.api#hostLabel')
-              next unless member_ref.location_name == label
+            input.members.each do |member_name, member_shape|
+              next unless member_shape.traits.key?('smithy.api#hostLabel')
+              next unless member_shape.location_name == label
 
               name = member_name
             end
diff --git a/gems/smithy-client/lib/smithy-client/plugins/idempotency_token.rb b/gems/smithy-client/lib/smithy-client/plugins/idempotency_token.rb
index bd57b084b..1fc7989f7 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/idempotency_token.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/idempotency_token.rb
@@ -21,8 +21,8 @@ def call(context)
           private
 
           def apply_idempotency_token(input, params)
-            input.target.members.each do |member_name, member_ref|
-              next unless member_ref.traits.key?('smithy.api#idempotencyToken')
+            input.members.each do |member_name, member_shape|
+              next unless member_shape.traits.key?('smithy.api#idempotencyToken')
 
               params[member_name] ||= SecureRandom.uuid
             end
diff --git a/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb b/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb
index 44ff7e27a..6e4d23573 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/request_compression.rb
@@ -92,9 +92,9 @@ def request_encoding_selection(context)
           end
 
           def streaming?(input)
-            input.target.members.any? do |_, member_ref|
-              member_ref.target.traits.key?('smithy.api#streaming') &&
-                !member_ref.target.traits.key?('smithy.api#requiresLength')
+            input.members.any? do |_, member_shape|
+              member_shape.target.traits.key?('smithy.api#streaming') &&
+                !member_shape.target.traits.key?('smithy.api#requiresLength')
             end
           end
 
diff --git a/gems/smithy-client/lib/smithy-client/plugins/transfer_encoding.rb b/gems/smithy-client/lib/smithy-client/plugins/transfer_encoding.rb
index 389ec9486..7c34ba8ee 100644
--- a/gems/smithy-client/lib/smithy-client/plugins/transfer_encoding.rb
+++ b/gems/smithy-client/lib/smithy-client/plugins/transfer_encoding.rb
@@ -11,31 +11,31 @@ class TransferEncoding < Plugin
         # @api private
         class Handler < Client::Handler
           def call(context)
-            payload_ref = streaming_member_ref(context)
+            payload_member = streaming_member(context)
             # Proceed with TE header logic IFF there's a streaming payload.
-            apply_transfer_encoding(context, payload_ref.target) if payload_ref
+            apply_transfer_encoding(context, payload_member.target) if payload_member
             @handler.call(context)
           end
 
           private
 
-          def apply_transfer_encoding(context, payload)
+          def apply_transfer_encoding(context, payload_shape)
             return if context.http_request.body.respond_to?(:size)
-            if requires_length?(payload)
+            if requires_length?(payload_shape)
               raise Smithy::Client::Errors::MissingContentLength
             elsif unsigned_payload?(context)
               context.http_request.headers['Transfer-Encoding'] = 'chunked'
             end
           end
 
-          def streaming_member_ref(context)
-            context.operation.input.members.detect do |_, ref|
-              ref.target.traits.key?('smithy.api#streaming')
+          def streaming_member(context)
+            context.operation.input.members.detect do |_, member_shape|
+              member_shape.target.traits.key?('smithy.api#streaming')
             end&.last
           end
 
-          def requires_length?(payload)
-            payload.traits.key?('smithy.api#requiresLength')
+          def requires_length?(shape)
+            shape.traits.key?('smithy.api#requiresLength')
           end
 
           def unsigned_payload?(context)
diff --git a/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/handler.rb b/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/handler.rb
index 8f0f1a49c..8fc724807 100644
--- a/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/handler.rb
+++ b/gems/smithy-client/lib/smithy-client/rpc_v2_cbor/handler.rb
@@ -36,7 +36,7 @@ def apply_content_type_header(context)
           content_type =
             if event_stream?(input)
               'application/vnd.amazon.eventstream'
-            elsif input.target != Schema::Shapes::Prelude::Unit
+            elsif input != Schema::Shapes::Prelude::Unit
               'application/cbor'
             end
 
@@ -64,9 +64,9 @@ def apply_url_path(context)
           base.path += "/service/#{service_name}/operation/#{context.operation.name}"
         end
 
-        def event_stream?(ref)
-          ref.target.members.each_value do |member_ref|
-            shape = member_ref.target
+        def event_stream?(input_shape)
+          input_shape.members.each_value do |member_shape|
+            shape = member_shape.target
             return true if shape.traits.key?('smithy.api#streaming') && shape.is_a?(Schema::Shapes::UnionShape)
           end
           false
diff --git a/gems/smithy-client/lib/smithy-client/stubbing/data_applicator.rb b/gems/smithy-client/lib/smithy-client/stubbing/data_applicator.rb
index 2ea15052c..62916a900 100644
--- a/gems/smithy-client/lib/smithy-client/stubbing/data_applicator.rb
+++ b/gems/smithy-client/lib/smithy-client/stubbing/data_applicator.rb
@@ -8,50 +8,50 @@ module Stubbing
       class DataApplicator
         include Smithy::Schema::Shapes
 
-        def initialize(ref)
-          @ref = ref
+        def initialize(shape)
+          @shape = shape
         end
 
         def apply(data, stub)
-          structure(@ref, data, stub)
+          structure(@shape, data, stub)
         end
 
         private
 
-        def shape(ref, value, stub = nil)
-          case ref.target
-          when StructureShape then structure(ref, value, stub)
-          when ListShape then list(ref, value)
-          when MapShape then map(ref, value)
+        def apply_shape(shape, value, stub = nil)
+          case shape.target
+          when StructureShape then structure(shape, value, stub)
+          when ListShape then list(shape, value)
+          when MapShape then map(shape, value)
           else value
           end
         end
 
-        def list(ref, value)
+        def list(shape, value)
           return if value.nil?
 
-          shape = ref.target
+          shape = shape.target
           value.each_with_object([]) do |v, list|
-            list << shape(shape.member, v)
+            list << apply_shape(shape.member, v)
           end
         end
 
-        def map(ref, value)
+        def map(shape, value)
           return if value.nil?
 
-          shape = ref.target
+          shape = shape.target
           value.each_with_object({}) do |(k, v), map|
-            map[k.to_s] = shape(shape.value, v)
+            map[k.to_s] = apply_shape(shape.value, v)
           end
         end
 
-        def structure(ref, data, stub)
+        def structure(shape, data, stub)
           return if data.nil?
 
-          stub = ref.target.type.new if stub.nil?
-          shape = ref.target
+          stub = shape.target.type.new if stub.nil?
+          shape = shape.target
           data.each_pair do |key, value|
-            stub[key] = shape(shape.member(key), value)
+            stub[key] = apply_shape(shape.member(key), value)
           end
           stub
         end
diff --git a/gems/smithy-client/lib/smithy-client/stubbing/empty_stub.rb b/gems/smithy-client/lib/smithy-client/stubbing/empty_stub.rb
index ed1de27d0..d463ee7a6 100644
--- a/gems/smithy-client/lib/smithy-client/stubbing/empty_stub.rb
+++ b/gems/smithy-client/lib/smithy-client/stubbing/empty_stub.rb
@@ -10,53 +10,53 @@ module Stubbing
       class EmptyStub
         include Smithy::Schema::Shapes
 
-        def initialize(ref)
-          @ref = ref
+        def initialize(shape)
+          @shape = shape
         end
 
         # @return [Schema::Structure, Schema::EmptyStructure]
         def stub
-          structure(@ref, [])
+          structure(@shape, [])
         end
 
         private
 
-        def shape(ref, visited)
-          shape = ref.target
-          return nil if visited.include?(shape)
+        def stub_shape(shape, visited)
+          resolved_shape = shape.target
+          return nil if visited.include?(resolved_shape)
 
-          visited += [shape]
+          visited += [resolved_shape]
 
-          case shape
+          case resolved_shape
           when ListShape then []
           when MapShape then {}
-          when StructureShape then structure(ref, visited)
-          when UnionShape then union(ref, visited)
-          else scalar(ref)
+          when StructureShape then structure(shape, visited)
+          when UnionShape then union(shape, visited)
+          else scalar(shape)
           end
         end
 
-        def structure(ref, visited)
-          shape = ref.target
-          shape.members.each_with_object(shape.type.new) do |(member_name, member_ref), struct|
-            struct[member_name] = shape(member_ref, visited)
+        def structure(shape, visited)
+          shape = shape.target
+          shape.members.each_with_object(shape.type.new) do |(member_name, member_shape), struct|
+            struct[member_name] = stub_shape(member_shape, visited)
           end
         end
 
-        def union(ref, visited)
-          shape = ref.target
-          member_name, member_ref = shape.members.first
+        def union(shape, visited)
+          shape = shape.target
+          member_name, member_shape = shape.members.first
           return unless member_name
 
-          value = shape(member_ref, visited)
+          value = stub_shape(member_shape, visited)
           klass = shape.member_type(member_name)
           klass.new(member_name => value)
         end
 
-        def scalar(ref)
-          case ref.target
+        def scalar(shape)
+          case shape.target
           when BigDecimalShape then BigDecimal(0)
-          when BlobShape, EnumShape, StringShape then ref.location_name
+          when BlobShape, EnumShape, StringShape then shape.location_name
           when BooleanShape then false
           when IntegerShape, IntEnumShape then 0
           when FloatShape then 0.0
diff --git a/gems/smithy-client/spec/smithy-client/plugins/transfer_encoding_spec.rb b/gems/smithy-client/spec/smithy-client/plugins/transfer_encoding_spec.rb
index 664420d2b..15570a688 100644
--- a/gems/smithy-client/spec/smithy-client/plugins/transfer_encoding_spec.rb
+++ b/gems/smithy-client/spec/smithy-client/plugins/transfer_encoding_spec.rb
@@ -25,8 +25,8 @@ module Plugins
         let(:streaming_body_plugin) do
           handler_class = Class.new(Client::Handler) do
             def call(context)
-              context.operation.input.target.members.each do |name, ref|
-                if ref.target.traits.key?('smithy.api#streaming') && context.params[name.to_sym]
+              context.operation.input.members.each do |name, shape|
+                if shape.target.traits.key?('smithy.api#streaming') && context.params[name.to_sym]
                   context.http_request.body = context.params[name.to_sym]
                   break
                 end
diff --git a/gems/smithy-xml/spec/smithy-xml/builder_spec.rb b/gems/smithy-xml/spec/smithy-xml/builder_spec.rb
index bcbec1641..e1f696655 100644
--- a/gems/smithy-xml/spec/smithy-xml/builder_spec.rb
+++ b/gems/smithy-xml/spec/smithy-xml/builder_spec.rb
@@ -16,8 +16,8 @@ def inline(xml)
       end
 
       it 'returns an empty frame when given a unit shape' do
-        ref = Schema::Shapes::MemberShape.new(target: Schema::Shapes::Prelude::Unit)
-        expect(subject.build(ref, '')).to eq('<Unit/>')
+        shape = Schema::Shapes::MemberShape.new(target: Schema::Shapes::Prelude::Unit)
+        expect(subject.build(shape, '')).to eq('<Unit/>')
       end
 
       context 'structures' do

From d5b50311b348b8eca111724dbf9db8d1c028e246 Mon Sep 17 00:00:00 2001
From: Juli Tera <terajul@amazon.com>
Date: Fri, 5 Jun 2026 08:50:19 -0700
Subject: [PATCH 19/23] Update param helpers shape references

---
 .../lib/smithy-client/default_params.rb       | 48 +++++------
 .../lib/smithy-client/log_param_filter.rb     | 66 +++++++--------
 .../lib/smithy-client/param_converter.rb      | 54 ++++++-------
 .../lib/smithy-client/param_validator.rb      | 80 +++++++++----------
 .../smithy-client/log_param_filter_spec.rb    |  4 +-
 .../smithy-client/param_converter_spec.rb     |  4 +-
 6 files changed, 128 insertions(+), 128 deletions(-)

diff --git a/gems/smithy-client/lib/smithy-client/default_params.rb b/gems/smithy-client/lib/smithy-client/default_params.rb
index 8d879527b..ea4105b32 100644
--- a/gems/smithy-client/lib/smithy-client/default_params.rb
+++ b/gems/smithy-client/lib/smithy-client/default_params.rb
@@ -9,70 +9,70 @@ module Client
     class DefaultParams
       include Schema::Shapes
 
-      def initialize(ref)
-        @ref = ref
+      def initialize(shape)
+        @shape = shape
       end
 
       # @param [Hash] params
       # @return [Hash]
       def apply(params)
-        structure(@ref, params)
+        structure(@shape, params)
       end
 
       private
 
-      def shape(ref, value)
-        case ref.target
-        when ListShape then list(ref, value)
-        when MapShape then map(ref, value)
-        when StructureShape then structure(ref, value)
+      def apply_shape(shape, value)
+        case shape.target
+        when ListShape then list(shape, value)
+        when MapShape then map(shape, value)
+        when StructureShape then structure(shape, value)
         else value
         end
       end
 
-      def list(ref, values)
+      def list(shape, values)
         return if values.nil?
 
-        shape = ref.target
+        member = shape.target.member
         values.each do |value|
-          shape(shape.member, value)
+          apply_shape(member, value)
         end
         values
       end
 
-      def map(ref, values)
+      def map(shape, values)
         return if values.nil?
 
-        shape = ref.target
+        value_shape = shape.target.value
         values.each_pair do |_key, value|
-          shape(shape.value, value)
+          apply_shape(value_shape, value)
         end
         values
       end
 
-      def structure(ref, values)
+      def structure(shape, values)
         return if values.nil?
 
-        ref.target.members.each do |member_name, member_ref|
+        shape.target.members.each do |member_name, member_shape|
           value = values[member_name]
-          value ||= default(member_ref) if default?(ref, member_ref.traits)
-          next if value.nil? && !default?(ref, member_ref.traits) # default can have nil values
+          value ||= default(member_shape) if default?(shape, member_shape.traits)
+          next if value.nil? && !default?(shape, member_shape.traits) # default can have nil values
 
-          values[member_name] = shape(member_ref, value)
+          values[member_name] = apply_shape(member_shape, value)
         end
         values
       end
 
-      def default?(ref, traits)
+      def default?(shape, traits)
         # skip defaults for top level members
-        return false if ref == @ref
+        return false if shape == @shape
 
         traits.include?('smithy.api#default') && !traits.include?('smithy.api#clientOptional')
       end
 
-      def default(ref)
-        default = ref.traits['smithy.api#default']
-        case ref.target
+      def default(member_shape)
+        default = member_shape.traits['smithy.api#default']
+        case member_shape.target
         when BlobShape then Base64.strict_decode64(default)
         when TimestampShape then timestamp_default(default)
         else default
diff --git a/gems/smithy-client/lib/smithy-client/log_param_filter.rb b/gems/smithy-client/lib/smithy-client/log_param_filter.rb
index 551c9e849..d5b0697dc 100644
--- a/gems/smithy-client/lib/smithy-client/log_param_filter.rb
+++ b/gems/smithy-client/lib/smithy-client/log_param_filter.rb
@@ -10,71 +10,71 @@ def initialize(options = {})
         @filter_sensitive_params = options.fetch(:filter_sensitive_params, true)
       end
 
-      def filter(ref, values)
-        case ref.target
-        when ListShape then list(ref, values)
-        when MapShape then map(ref, values)
-        when StructureShape then structure(ref, values)
-        when UnionShape then union(ref, values)
-        else scalar(ref, values)
+      def filter(shape, values)
+        case shape.target
+        when ListShape then list(shape, values)
+        when MapShape then map(shape, values)
+        when StructureShape then structure(shape, values)
+        when UnionShape then union(shape, values)
+        else scalar(shape, values)
         end
       end
 
       private
 
-      def list(ref, values)
-        shape = ref.target
-        return '[FILTERED]' if sensitive?(shape)
+      def list(shape, values)
+        target = shape.target
+        return '[FILTERED]' if sensitive?(target)
 
-        member_ref = shape.member
-        values.collect { |value| filter(member_ref, value) }
+        member = target.member
+        values.collect { |value| filter(member, value) }
       end
 
-      def map(ref, values)
-        shape = ref.target
-        return '[FILTERED]' if sensitive?(shape)
+      def map(shape, values)
+        target = shape.target
+        return '[FILTERED]' if sensitive?(target)
 
         filtered = {}
-        value_ref = shape.value
+        value_shape = target.value
         values.each_pair do |key, value|
-          filtered[key] = filter(value_ref, value)
+          filtered[key] = filter(value_shape, value)
         end
         filtered
       end
 
-      def scalar(ref, value)
-        return '[FILTERED]' if sensitive?(ref.target)
+      def scalar(shape, value)
+        return '[FILTERED]' if sensitive?(shape.target)
 
         value
       end
 
-      def structure(ref, values)
-        shape = ref.target
-        return '[FILTERED]' if sensitive?(shape)
+      def structure(shape, values)
+        target = shape.target
+        return '[FILTERED]' if sensitive?(target)
 
         filtered = {}
         values.each_pair do |key, value|
-          next unless shape.member?(key)
+          next unless target.member?(key)
 
-          member_ref = shape.member(key)
-          filtered[key] = filter(member_ref, value)
+          member_shape = target.member(key)
+          filtered[key] = filter(member_shape, value)
         end
         filtered
       end
 
-      def union(ref, values) # rubocop:disable Metrics/AbcSize
-        shape = ref.target
-        return '[FILTERED]' if sensitive?(shape)
+      def union(shape, values)
+        target = shape.target
+        return '[FILTERED]' if sensitive?(target)
 
         filtered = {}
         if values.is_a?(Schema::Union)
-          name, member_ref = ref.target.member_by_type(values.class)
-          filtered[name] = filter(member_ref, values.value)
+          name, member_shape = target.member_by_type(values.class)
+          filtered[name] = filter(member_shape, values.value)
         else
           key, value = values.first
-          if ref.target.member?(key)
-            member_ref = ref.target.member(key)
-            filtered[key] = filter(member_ref, value)
+          if target.member?(key)
+            member_shape = target.member(key)
+            filtered[key] = filter(member_shape, value)
           end
         end
         filtered
diff --git a/gems/smithy-client/lib/smithy-client/param_converter.rb b/gems/smithy-client/lib/smithy-client/param_converter.rb
index a28633225..ea2d71cb3 100644
--- a/gems/smithy-client/lib/smithy-client/param_converter.rb
+++ b/gems/smithy-client/lib/smithy-client/param_converter.rb
@@ -15,8 +15,8 @@ class ParamConverter
       @mutex = Mutex.new
       @converters = Hash.new { |h, k| h[k] = {} }
 
-      def initialize(ref)
-        @ref = ref
+      def initialize(shape)
+        @shape = shape
         @opened_files = []
       end
 
@@ -25,7 +25,7 @@ def initialize(ref)
       # @param [Hash] params
       # @return [Hash]
       def convert(params)
-        structure(@ref, params)
+        structure(@shape, params)
       end
 
       def close_opened_files
@@ -35,58 +35,58 @@ def close_opened_files
 
       private
 
-      def c(ref, value)
-        self.class.c(ref.target.class, value, self)
+      def c(shape, value)
+        self.class.c(shape.target.class, value, self)
       end
 
-      def shape(ref, value)
-        case ref.target
-        when ListShape then list(ref, value)
-        when MapShape then map(ref, value)
-        when StructureShape then structure(ref, value)
-        when UnionShape then union(ref, value)
-        else c(ref, value)
+      def convert_shape(shape, value)
+        case shape.target
+        when ListShape then list(shape, value)
+        when MapShape then map(shape, value)
+        when StructureShape then structure(shape, value)
+        when UnionShape then union(shape, value)
+        else c(shape, value)
         end
       end
 
-      def list(ref, values)
-        values = c(ref, values)
+      def list(shape, values)
+        values = c(shape, values)
         return values unless values.is_a?(Array)
 
-        values.collect { |v| shape(ref.target.member, v) }
+        values.collect { |v| convert_shape(shape.target.member, v) }
       end
 
-      def map(ref, values)
-        values = c(ref, values)
+      def map(shape, values)
+        values = c(shape, values)
         return values unless values.is_a?(Hash)
 
         values.each.with_object({}) do |(key, value), hash|
-          hash[shape(ref.target.key, key)] = shape(ref.target.value, value)
+          hash[convert_shape(shape.target.key, key)] = convert_shape(shape.target.value, value)
         end
       end
 
-      def structure(ref, values)
-        values = c(ref, values)
+      def structure(shape, values)
+        values = c(shape, values)
         return values unless values.respond_to?(:each_pair)
 
         values.each_pair do |k, v|
           next if v.nil?
-          next unless ref.target.member?(k)
+          next unless shape.target.member?(k)
 
-          values[k] = shape(ref.target.member(k), v)
+          values[k] = convert_shape(shape.target.member(k), v)
         end
         values
       end
 
-      def union(ref, values)
-        values = c(ref, values)
+      def union(shape, values)
+        values = c(shape, values)
 
         if values.is_a?(Schema::Union)
-          _name, member_ref = ref.target.member_by_type(values.class)
-          values = shape(member_ref, values)
+          _name, member_shape = shape.target.member_by_type(values.class)
+          values = convert_shape(member_shape, values)
         elsif values.is_a?(Hash)
           key, value = values.first
-          values[key] = shape(ref.target.member(key), value)
+          values[key] = convert_shape(shape.target.member(key), value)
         end
         values
       end
diff --git a/gems/smithy-client/lib/smithy-client/param_validator.rb b/gems/smithy-client/lib/smithy-client/param_validator.rb
index 1bede2ab9..b27cb7753 100644
--- a/gems/smithy-client/lib/smithy-client/param_validator.rb
+++ b/gems/smithy-client/lib/smithy-client/param_validator.rb
@@ -10,8 +10,8 @@ class ParamValidator
 
       EXPECTED_GOT = 'expected %s to be %s, got class %s instead.'
 
-      def initialize(ref, validate_required: true)
-        @ref = ref
+      def initialize(shape, validate_required: true)
+        @shape = shape
         @validate_required = validate_required
       end
 
@@ -21,20 +21,20 @@ def initialize(ref, validate_required: true)
       # @raise [ArgumentError] if the params are invalid
       def validate!(params, context: 'params')
         errors = []
-        structure(@ref, params, errors, context)
+        structure(@shape, params, errors, context)
         raise ArgumentError, error_messages(errors) unless errors.empty?
       end
 
       private
 
       # rubocop:disable Metrics
-      def shape(ref, value, errors, context)
-        case ref.target
-        when StructureShape then structure(ref, value, errors, context)
-        when ListShape then list(ref, value, errors, context)
-        when MapShape then map(ref, value, errors, context)
-        when DocumentShape then document(ref, value, errors, context)
-        when UnionShape then union(ref, value, errors, context)
+      def validate_shape(shape, value, errors, context)
+        case shape.target
+        when StructureShape then structure(shape, value, errors, context)
+        when ListShape then list(shape, value, errors, context)
+        when MapShape then map(shape, value, errors, context)
+        when DocumentShape then document(shape, value, errors, context)
+        when UnionShape then union(shape, value, errors, context)
         when StringShape, EnumShape
           errors << expected_got(context, 'a String', value) unless value.is_a?(String)
         when IntegerShape, IntEnumShape
@@ -49,7 +49,7 @@ def shape(ref, value, errors, context)
           errors << expected_got(context, 'true or false', value) unless [true, false].include?(value)
         when BlobShape
           unless value.is_a?(String)
-            if streaming_input?(ref)
+            if streaming_input?(shape)
               unless io_like?(value)
                 errors << expected_got(
                   context,
@@ -87,7 +87,7 @@ def document(shape, value, errors, context)
         end
       end
 
-      def list(ref, values, errors, context)
+      def list(shape, values, errors, context)
         unless values.is_a?(Array)
           errors << expected_got(context, 'an Array', values)
           return
@@ -96,47 +96,47 @@ def list(ref, values, errors, context)
         values.each.with_index do |value, index|
           next unless value
 
-          shape(ref.target.member, value, errors, context + "[#{index}]")
+          validate_shape(shape.target.member, value, errors, context + "[#{index}]")
         end
       end
 
-      def map(ref, values, errors, context)
+      def map(shape, values, errors, context)
         unless values.is_a?(Hash)
           errors << expected_got(context, 'a Hash', values)
           return
         end
 
         values.each do |key, value|
-          shape(ref.target.key, key, errors, "#{context} #{key.inspect} key")
+          validate_shape(shape.target.key, key, errors, "#{context} #{key.inspect} key")
           next unless value
 
-          shape(ref.target.value, value, errors, context + "[#{key.inspect}]")
+          validate_shape(shape.target.value, value, errors, context + "[#{key.inspect}]")
         end
       end
 
-      def member(ref, name, value, errors, context)
-        if ref.target.member?(name)
-          member_ref = ref.target.member(name)
-          shape(member_ref, value, errors, context + "[#{name.inspect}]")
+      def member(shape, name, value, errors, context)
+        if shape.target.member?(name)
+          member_shape = shape.target.member(name)
+          validate_shape(member_shape, value, errors, context + "[#{name.inspect}]")
         else
           errors << "unexpected value at #{context}[#{name.inspect}]"
         end
       end
 
-      def structure(ref, values, errors, context)
-        return if ref.target == Prelude::Unit
-        return unless valid_structure?(ref, values, errors, context)
+      def structure(shape, values, errors, context)
+        return if shape.target == Prelude::Unit
+        return unless valid_structure?(shape, values, errors, context)
 
-        validate_required_members(ref, values, errors, context) if @validate_required
+        validate_required_members(shape, values, errors, context) if @validate_required
         values.each_pair do |name, value|
           next if value.nil?
 
-          member(ref, name, value, errors, context)
+          member(shape, name, value, errors, context)
         end
       end
 
-      def valid_structure?(ref, values, errors, context)
-        if !values.is_a?(Hash) && !values.is_a?(ref.target.type)
+      def valid_structure?(shape, values, errors, context)
+        if !values.is_a?(Hash) && !values.is_a?(shape.target.type)
           errors << expected_got(context, 'a Hash', values)
           return false
         end
@@ -144,23 +144,23 @@ def valid_structure?(ref, values, errors, context)
         true
       end
 
-      def union(ref, values, errors, context)
-        return unless valid_union?(ref, values, errors, context)
+      def union(shape, values, errors, context)
+        return unless valid_union?(shape, values, errors, context)
 
         if values.is_a?(Schema::Union)
-          _name, member_ref = ref.target.member_by_type(values.class)
-          shape(member_ref, values.value, errors, context)
+          _name, member_shape = shape.target.member_by_type(values.class)
+          validate_shape(member_shape, values.value, errors, context)
         elsif values.is_a?(Hash)
           values.each_pair do |name, value|
             next if value.nil?
 
-            member(ref, name, value, errors, context)
+            member(shape, name, value, errors, context)
           end
         end
       end
 
-      def valid_union?(ref, values, errors, context)
-        return true if values.is_a?(ref.target.type)
+      def valid_union?(shape, values, errors, context)
+        return true if values.is_a?(shape.target.type)
 
         unless values.is_a?(Hash)
           errors << expected_got(context, 'a Hash', values)
@@ -168,15 +168,15 @@ def valid_union?(ref, values, errors, context)
         end
         return true if values.size <= 1
 
-        union_members = ref.target.members.keys.join(', ')
+        union_members = shape.target.members.keys.join(', ')
         error = "expected #{context} to be a Hash with one of #{union_members}, got #{values.size} keys instead."
         errors << error
         false
       end
 
-      def validate_required_members(ref, values, errors, context)
-        ref.target.members.each do |name, member_ref|
-          traits = member_ref.traits
+      def validate_required_members(shape, values, errors, context)
+        shape.target.members.each do |name, member_shape|
+          traits = member_shape.traits
           next unless traits.key?('smithy.api#required') && !traits.key?('smithy.api#clientOptional')
 
           if values[name].nil?
@@ -186,8 +186,8 @@ def validate_required_members(ref, values, errors, context)
         end
       end
 
-      def streaming_input?(ref)
-        ref.target.traits.key?('smithy.api#streaming')
+      def streaming_input?(shape)
+        shape.target.traits.key?('smithy.api#streaming')
       end
 
       def io_like?(value, require_size: false)
diff --git a/gems/smithy-client/spec/smithy-client/log_param_filter_spec.rb b/gems/smithy-client/spec/smithy-client/log_param_filter_spec.rb
index c18d2b3c3..882fb7760 100644
--- a/gems/smithy-client/spec/smithy-client/log_param_filter_spec.rb
+++ b/gems/smithy-client/spec/smithy-client/log_param_filter_spec.rb
@@ -35,7 +35,7 @@ module Client
             'target' => 'smithy.ruby.tests#SensitiveStructure'
           }
 
-          sensitive_structure = input.target.member(:sensitive_structure).target.type
+          sensitive_structure = input.member(:sensitive_structure).target.type
           filtered = subject.filter(input, { sensitive_structure: sensitive_structure.new(string: 'sensitive') })
           expect(filtered).to eq(sensitive_structure: '[FILTERED]')
         end
@@ -120,7 +120,7 @@ module Client
 
         it 'filters sensitive unions as a type' do
           shapes['smithy.ruby.tests#Union']['traits'] = { 'smithy.api#sensitive' => {} }
-          union = input.target.member(:union).target.member_type(:string)
+          union = input.member(:union).target.member_type(:string)
           filtered = subject.filter(input, { union: union.new(string: 'sensitive') })
           expect(filtered).to eq(union: '[FILTERED]')
         end
diff --git a/gems/smithy-client/spec/smithy-client/param_converter_spec.rb b/gems/smithy-client/spec/smithy-client/param_converter_spec.rb
index 87d7dc9f8..30b19da24 100644
--- a/gems/smithy-client/spec/smithy-client/param_converter_spec.rb
+++ b/gems/smithy-client/spec/smithy-client/param_converter_spec.rb
@@ -49,8 +49,8 @@ module Client
         end
 
         it 'performs a deeply nested conversion of values when using types' do
-          structure_type = input.target.type
-          union_type = input.target.member(:union).target.member_type(:structure)
+          structure_type = input.type
+          union_type = input.member(:union).target.member_type(:structure)
           params = structure_type.new(
             structure: structure_type.new(boolean: 'true'),
             map: 'not a map',

From e36db8b51b77c4b55abcb8e4ce2a852cc959a04c Mon Sep 17 00:00:00 2001
From: Juli Tera <terajul@amazon.com>
Date: Fri, 5 Jun 2026 08:50:42 -0700
Subject: [PATCH 20/23] Update document_utils shape references

---
 .../document_utils/deserializer.rb            | 65 +++++++++--------
 .../document_utils/serializer.rb              | 71 +++++++++----------
 2 files changed, 67 insertions(+), 69 deletions(-)

diff --git a/gems/smithy-schema/lib/smithy-schema/document_utils/deserializer.rb b/gems/smithy-schema/lib/smithy-schema/document_utils/deserializer.rb
index d4b5635fd..ad044d082 100644
--- a/gems/smithy-schema/lib/smithy-schema/document_utils/deserializer.rb
+++ b/gems/smithy-schema/lib/smithy-schema/document_utils/deserializer.rb
@@ -12,23 +12,22 @@ def initialize(options = {})
           @type_registry = options[:type_registry]
         end
 
-        def deserialize(data, shape, target)
-          ref = shape.is_a?(MemberShape) ? shape : MemberShape.new(target: shape)
-          shape(ref, data, target)
+        def deserialize(data, shape, result)
+          deserialize_shape(shape, data, result)
         end
 
         private
 
-        def shape(ref, value, target = nil) # rubocop:disable Metrics/CyclomaticComplexity
-          case ref.target
+        def deserialize_shape(shape, value, result = nil) # rubocop:disable Metrics/CyclomaticComplexity
+          case shape.target
           when BlobShape then Base64.strict_decode64(value)
           when DocumentShape then document(value)
           when FloatShape then float(value)
-          when ListShape then list(ref, value, target)
-          when MapShape then map(ref, value, target)
-          when StructureShape then structure(ref, value, target)
+          when ListShape then list(shape, value, result)
+          when MapShape then map(shape, value, result)
+          when StructureShape then structure(shape, value, result)
           when TimestampShape then timestamp(value)
-          when UnionShape then union(ref, value, target)
+          when UnionShape then union(shape, value, result)
           else value
           end
         end
@@ -39,7 +38,7 @@ def document(values)
           msg = 'invalid document - document discriminator not found in type registry'
           raise ArgumentError, msg unless @type_registry.key?(values['__type'])
 
-          shape(MemberShape.new(target: @type_registry[values['__type']]), values)
+          deserialize_shape(@type_registry[values['__type']], values)
         end
 
         def float(value)
@@ -52,35 +51,35 @@ def float(value)
           end
         end
 
-        def list(ref, values, target = nil)
+        def list(shape, values, result = nil)
           return if values.nil?
 
-          target = [] if target.nil?
+          result = [] if result.nil?
           values.each do |value|
-            target << shape(ref.target.member, value) unless value.nil?
+            result << deserialize_shape(shape.target.member, value) unless value.nil?
           end
-          target
+          result
         end
 
-        def map(ref, values, target = nil)
+        def map(shape, values, result = nil)
           return if values.nil?
 
-          target = {} if target.nil?
+          result = {} if result.nil?
           values.each do |key, value|
-            target[key] = shape(ref.target.value, value) unless value.nil?
+            result[key] = deserialize_shape(shape.target.value, value) unless value.nil?
           end
-          target
+          result
         end
 
-        def structure(ref, values, target = nil)
+        def structure(shape, values, result = nil)
           return if values.nil?
 
-          target = ref.target.type.new if target.nil?
-          ref.target.members.each do |member_name, member_ref|
-            value = values[location_name(member_ref)]
-            target[member_name] = shape(member_ref, value) unless value.nil?
+          result = shape.target.type.new if result.nil?
+          shape.target.members.each do |member_name, member_shape|
+            value = values[location_name(member_shape)]
+            result[member_name] = deserialize_shape(member_shape, value) unless value.nil?
           end
-          target
+          result
         end
 
         def timestamp(value)
@@ -100,24 +99,24 @@ def timestamp(value)
           end
         end
 
-        def union(ref, values, target = nil) # rubocop:disable Metrics/AbcSize
-          ref.target.members.each do |member_name, member_ref|
-            value = values[location_name(member_ref)]
+        def union(shape, values, result = nil) # rubocop:disable Metrics/AbcSize
+          shape.target.members.each do |member_name, member_shape|
+            value = values[location_name(member_shape)]
             next if value.nil?
 
-            target = ref.target.member_type(member_name) if target.nil?
-            return target.new(member_name => shape(member_ref, value))
+            result = shape.target.member_type(member_name) if result.nil?
+            return result.new(member_name => deserialize_shape(member_shape, value))
           end
 
           values.delete('__type')
           key, value = values.first
-          ref.target.member_type(:unknown).new(key, value)
+          shape.target.member_type(:unknown).new(key, value)
         end
 
-        def location_name(ref)
-          return ref.location_name unless @json_name
+        def location_name(member_shape)
+          return member_shape.location_name unless @json_name
 
-          ref.traits['smithy.api#jsonName'] || ref.location_name
+          member_shape.traits['smithy.api#jsonName'] || member_shape.location_name
         end
       end
     end
diff --git a/gems/smithy-schema/lib/smithy-schema/document_utils/serializer.rb b/gems/smithy-schema/lib/smithy-schema/document_utils/serializer.rb
index 7be3e0edf..b65a04fe2 100644
--- a/gems/smithy-schema/lib/smithy-schema/document_utils/serializer.rb
+++ b/gems/smithy-schema/lib/smithy-schema/document_utils/serializer.rb
@@ -19,8 +19,7 @@ def initialize(options = {})
         end
 
         def format_document_data(shape, data)
-          ref = shape.is_a?(MemberShape) ? shape : MemberShape.new(target: shape)
-          document_data = shape(ref, data)
+          document_data = serialize_shape(shape, data)
           document_data['__type'] = shape.id
           document_data
         end
@@ -41,16 +40,16 @@ def serialize_untyped(values)
 
         private
 
-        def shape(ref, values) # rubocop:disable Metrics/CyclomaticComplexity
-          case ref.target
+        def serialize_shape(shape, values) # rubocop:disable Metrics/CyclomaticComplexity
+          case shape.target
           when BlobShape then blob(values)
           when DocumentShape then document(values)
           when FloatShape then float(values)
-          when ListShape then list(ref, values)
-          when MapShape then map(ref, values)
-          when StructureShape then structure(ref, values)
-          when TimestampShape then timestamp(ref, values)
-          when UnionShape then union(ref, values)
+          when ListShape then list(shape, values)
+          when MapShape then map(shape, values)
+          when StructureShape then structure(shape, values)
+          when TimestampShape then timestamp(shape, values)
+          when UnionShape then union(shape, values)
           else values
           end
         end
@@ -89,39 +88,39 @@ def float(value)
           end
         end
 
-        def list(ref, values)
+        def list(shape, values)
           return if values.nil?
 
-          shape = ref.target
+          member = shape.target.member
           values.collect do |value|
-            shape(shape.member, value)
+            serialize_shape(member, value)
           end
         end
 
-        def map(ref, values)
+        def map(shape, values)
           return if values.nil?
 
-          shape = ref.target
+          value_shape = shape.target.value
           values.each.with_object({}) do |(key, value), data|
-            data[key.to_s] = shape(shape.value, value)
+            data[key.to_s] = serialize_shape(value_shape, value)
           end
         end
 
-        def structure(ref, values)
+        def structure(shape, values)
           return if values.nil?
 
-          ref.target.members.each_with_object({}) do |(member_name, member_ref), data|
-            value = resolve_value(member_name, member_ref, values.to_h)
-            data[location_name(member_ref)] = shape(member_ref, value) unless value.nil?
+          shape.target.members.each_with_object({}) do |(member_name, member_shape), data|
+            value = resolve_value(member_name, member_shape, values.to_h)
+            data[location_name(member_shape)] = serialize_shape(member_shape, value) unless value.nil?
           end
         end
 
-        def timestamp(ref, value)
+        def timestamp(shape, value)
           value = normalize_timestamp_value(value)
           return value.to_i unless @timestamp_format
 
           trait = 'smithy.api#timestampFormat'
-          case ref.traits[trait] || ref.target.traits[trait]
+          case shape.traits[trait] || shape.target.traits[trait]
           when 'date-time' then value.utc.iso8601
           when 'http-date' then value.utc.httpdate
           else
@@ -130,26 +129,26 @@ def timestamp(ref, value)
           end
         end
 
-        def union(ref, values)
+        def union(shape, values)
           return if values.nil?
 
           data = {}
           if values.is_a?(Union)
-            _name, member_ref = ref.target.member_by_type(values.class)
-            data[location_name(member_ref)] = shape(member_ref, values)
+            _name, member_shape = shape.target.member_by_type(values.class)
+            data[location_name(member_shape)] = serialize_shape(member_shape, values)
           else
             key, value = values.first
-            if (member_ref = resolve_member_ref(ref, key))
-              data[location_name(member_ref)] = shape(member_ref, value)
+            if (member_shape = resolve_member_shape(shape, key))
+              data[location_name(member_shape)] = serialize_shape(member_shape, value)
             end
           end
           data
         end
 
-        def location_name(ref)
-          return ref.location_name unless @json_name
+        def location_name(member_shape)
+          return member_shape.location_name unless @json_name
 
-          ref.traits['smithy.api#jsonName'] || ref.location_name
+          member_shape.traits['smithy.api#jsonName'] || member_shape.location_name
         end
 
         def normalize_timestamp_value(value)
@@ -160,20 +159,20 @@ def normalize_timestamp_value(value)
           end
         end
 
-        def resolve_member_ref(ref, name)
-          return ref.target.member(name) if ref.target.member?(name)
+        def resolve_member_shape(shape, name)
+          return shape.target.member(name) if shape.target.member?(name)
 
-          ref.target.members.values.find do |member_ref|
-            member_ref.traits['smithy.api#jsonName'] == name || member_ref.location_name == name
+          shape.target.members.values.find do |member_shape|
+            member_shape.traits['smithy.api#jsonName'] == name || member_shape.location_name == name
           end
         end
 
-        def resolve_value(member_name, member_ref, values)
-          if (json_name = member_ref.traits['smithy.api#jsonName'])
+        def resolve_value(member_name, member_shape, values)
+          if (json_name = member_shape.traits['smithy.api#jsonName'])
             value = values[json_name]
             return value unless value.nil?
           end
-          values[member_name] || values[member_ref.location_name]
+          values[member_name] || values[member_shape.location_name]
         end
       end
     end

From 1c580798f5111ab416924675acfeae19de4e6e5d Mon Sep 17 00:00:00 2001
From: Juli Tera <terajul@amazon.com>
Date: Fri, 5 Jun 2026 09:00:02 -0700
Subject: [PATCH 21/23] Clean up remaining shape ref references

---
 gems/smithy-json/lib/smithy-json/builder.rb   |   8 +-
 .../smithy-schema/lib/smithy-schema/shapes.rb |  18 ++--
 .../spec/smithy-schema/shapes_spec.rb         | 102 +++++++++---------
 gems/smithy-xml/lib/smithy-xml/builder.rb     |  16 +--
 .../smithy-xml/lib/smithy-xml/parser/stack.rb |   2 +-
 5 files changed, 73 insertions(+), 73 deletions(-)

diff --git a/gems/smithy-json/lib/smithy-json/builder.rb b/gems/smithy-json/lib/smithy-json/builder.rb
index 7edf9677a..3aa7b5bfe 100644
--- a/gems/smithy-json/lib/smithy-json/builder.rb
+++ b/gems/smithy-json/lib/smithy-json/builder.rb
@@ -88,13 +88,13 @@ def union(shape, values) # rubocop:disable Metrics/AbcSize
 
         data = {}
         if values.is_a?(Schema::Union)
-          _name, member_ref = shape.target.member_by_type(values.class)
-          data[location_name(member_ref)] = build_shape(member_ref, values.value)
+          _name, member_shape = shape.target.member_by_type(values.class)
+          data[location_name(member_shape)] = build_shape(member_shape, values.value)
         else
           key, value = values.first
           if shape.target.member?(key)
-            member_ref = shape.target.member(key)
-            data[location_name(member_ref)] = build_shape(member_ref, value)
+            member_shape = shape.target.member(key)
+            data[location_name(member_shape)] = build_shape(member_shape, value)
           end
         end
         data
diff --git a/gems/smithy-schema/lib/smithy-schema/shapes.rb b/gems/smithy-schema/lib/smithy-schema/shapes.rb
index 9b832132c..271d6d1d2 100644
--- a/gems/smithy-schema/lib/smithy-schema/shapes.rb
+++ b/gems/smithy-schema/lib/smithy-schema/shapes.rb
@@ -161,8 +161,8 @@ def initialize(options = {})
         attr_accessor :members
 
         # @return [MemberShape]
-        def add_member(name, shape_ref)
-          @members[name] = shape_ref
+        def add_member(name, member_shape)
+          @members[name] = member_shape
         end
 
         # @param [Symbol] name
@@ -195,8 +195,8 @@ def initialize(options = {})
         attr_accessor :members
 
         # @return [MemberShape]
-        def add_member(name, shape_ref)
-          @members[name] = shape_ref
+        def add_member(name, member_shape)
+          @members[name] = member_shape
         end
 
         # @param [Symbol] name
@@ -244,8 +244,8 @@ def initialize(options = {})
         attr_accessor :type
 
         # @return [MemberShape]
-        def add_member(name, shape_ref)
-          @members[name] = shape_ref
+        def add_member(name, member_shape)
+          @members[name] = member_shape
         end
 
         # @param [Symbol] name
@@ -286,10 +286,10 @@ def initialize(options = {})
         attr_accessor :type
 
         # @return [MemberShape]
-        def add_member(name, type, shape_ref)
+        def add_member(name, type, member_shape)
           @member_types[name] = type
-          @members_by_type[type] = [name, shape_ref]
-          @members[name] = shape_ref
+          @members_by_type[type] = [name, member_shape]
+          @members[name] = member_shape
         end
 
         # @param [Symbol] name
diff --git a/gems/smithy-schema/spec/smithy-schema/shapes_spec.rb b/gems/smithy-schema/spec/smithy-schema/shapes_spec.rb
index feffeb7c3..72a036cb0 100644
--- a/gems/smithy-schema/spec/smithy-schema/shapes_spec.rb
+++ b/gems/smithy-schema/spec/smithy-schema/shapes_spec.rb
@@ -152,7 +152,7 @@ module Shapes
       describe OperationShape do
         subject { OperationShape.new }
 
-        let(:shape_ref) { MemberShape.new(target: StructureShape.new) }
+        let(:member_shape) { MemberShape.new(target: StructureShape.new) }
 
         it 'is a subclass of Shape' do
           expect(subject).to be_kind_of(Shape)
@@ -179,22 +179,22 @@ module Shapes
 
         context '#input' do
           it 'can get the input' do
-            subject = OperationShape.new(input: shape_ref)
-            expect(subject.input).to be(shape_ref)
+            subject = OperationShape.new(input: member_shape)
+            expect(subject.input).to be(member_shape)
           end
         end
 
         context '#output' do
           it 'can get the output' do
-            subject = OperationShape.new(output: shape_ref)
-            expect(subject.output).to be(shape_ref)
+            subject = OperationShape.new(output: member_shape)
+            expect(subject.output).to be(member_shape)
           end
         end
 
         context '#errors' do
           it 'can get a list of errors' do
-            subject = OperationShape.new(errors: [shape_ref])
-            expect(subject.errors).to eq([shape_ref])
+            subject = OperationShape.new(errors: [member_shape])
+            expect(subject.errors).to eq([member_shape])
           end
         end
       end
@@ -244,24 +244,24 @@ module Shapes
 
         describe '#add_member' do
           it 'adds a member reference' do
-            shape_ref = MemberShape.new(target: StringShape.new)
-            subject.add_member(:foo, shape_ref)
+            member_shape = MemberShape.new(target: StringShape.new)
+            subject.add_member(:foo, member_shape)
             expect(subject.members[:foo]).to be_kind_of(MemberShape)
           end
         end
 
         describe '#member?' do
           it 'returns true if member exists' do
-            shape_ref = MemberShape.new(target: StringShape.new)
-            subject.add_member(:foo, shape_ref)
+            member_shape = MemberShape.new(target: StringShape.new)
+            subject.add_member(:foo, member_shape)
             expect(subject.member?(:foo)).to be(true)
           end
         end
 
         describe '#member' do
           it 'returns the member' do
-            shape_ref = MemberShape.new(target: StringShape.new)
-            subject.add_member(:foo, shape_ref)
+            member_shape = MemberShape.new(target: StringShape.new)
+            subject.add_member(:foo, member_shape)
             expect(subject.member(:foo)).to be_kind_of(MemberShape)
           end
         end
@@ -288,24 +288,24 @@ module Shapes
 
         describe '#add_member' do
           it 'adds a member reference' do
-            shape_ref = MemberShape.new(target: StringShape.new)
-            subject.add_member(:foo, shape_ref)
+            member_shape = MemberShape.new(target: StringShape.new)
+            subject.add_member(:foo, member_shape)
             expect(subject.members[:foo]).to be_kind_of(MemberShape)
           end
         end
 
         describe '#member?' do
           it 'returns true if member exists' do
-            shape_ref = MemberShape.new(target: StringShape.new)
-            subject.add_member(:foo, shape_ref)
+            member_shape = MemberShape.new(target: StringShape.new)
+            subject.add_member(:foo, member_shape)
             expect(subject.member?(:foo)).to be(true)
           end
         end
 
         describe '#member' do
           it 'returns the member' do
-            shape_ref = MemberShape.new(target: StringShape.new)
-            subject.add_member(:foo, shape_ref)
+            member_shape = MemberShape.new(target: StringShape.new)
+            subject.add_member(:foo, member_shape)
             expect(subject.member(:foo)).to be_kind_of(MemberShape)
           end
         end
@@ -334,9 +334,9 @@ module Shapes
 
         describe '#member accessor' do
           it 'gets and sets a member' do
-            shape_ref = MemberShape.new(target: StringShape.new)
-            subject.member = shape_ref
-            expect(subject.member).to eq(shape_ref)
+            member_shape = MemberShape.new(target: StringShape.new)
+            subject.member = member_shape
+            expect(subject.member).to eq(member_shape)
           end
         end
       end
@@ -360,17 +360,17 @@ module Shapes
 
         describe '#key accessor' do
           it 'gets and sets a key' do
-            shape_ref = MemberShape.new(target: StringShape.new)
-            subject.key = shape_ref
-            expect(subject.key).to eq(shape_ref)
+            member_shape = MemberShape.new(target: StringShape.new)
+            subject.key = member_shape
+            expect(subject.key).to eq(member_shape)
           end
         end
 
         describe '#value accessor' do
           it 'gets and sets a value' do
-            shape_ref = MemberShape.new(target: StringShape.new)
-            subject.value = shape_ref
-            expect(subject.value).to eq(shape_ref)
+            member_shape = MemberShape.new(target: StringShape.new)
+            subject.value = member_shape
+            expect(subject.value).to eq(member_shape)
           end
         end
       end
@@ -403,24 +403,24 @@ module Shapes
 
         describe '#add_member' do
           it 'adds a member reference' do
-            shape_ref = MemberShape.new(target: StringShape.new)
-            subject.add_member(:foo, shape_ref)
+            member_shape = MemberShape.new(target: StringShape.new)
+            subject.add_member(:foo, member_shape)
             expect(subject.members[:foo]).to be_kind_of(MemberShape)
           end
         end
 
         describe '#member?' do
           it 'returns true if member exists' do
-            shape_ref = MemberShape.new(target: StringShape.new)
-            subject.add_member(:foo, shape_ref)
+            member_shape = MemberShape.new(target: StringShape.new)
+            subject.add_member(:foo, member_shape)
             expect(subject.member?(:foo)).to be(true)
           end
         end
 
         describe '#member' do
           it 'returns the member' do
-            shape_ref = MemberShape.new(target: StringShape.new)
-            subject.add_member(:foo, shape_ref)
+            member_shape = MemberShape.new(target: StringShape.new)
+            subject.add_member(:foo, member_shape)
             expect(subject.member(:foo)).to be_kind_of(MemberShape)
           end
         end
@@ -464,59 +464,59 @@ module Shapes
 
         describe '#add_member' do
           it 'adds a member with its type' do
-            shape_ref = MemberShape.new(target: StringShape.new)
-            subject.add_member(:foo, union_type, shape_ref)
-            expect(subject.members[:foo]).to be(shape_ref)
+            member_shape = MemberShape.new(target: StringShape.new)
+            subject.add_member(:foo, union_type, member_shape)
+            expect(subject.members[:foo]).to be(member_shape)
             expect(subject.member_types[:foo]).to be(union_type)
-            expect(subject.members_by_type[union_type]).to eq([:foo, shape_ref])
+            expect(subject.members_by_type[union_type]).to eq([:foo, member_shape])
           end
         end
 
         describe '#member?' do
           it 'returns true if member exists' do
-            shape_ref = MemberShape.new(target: StringShape.new)
-            subject.add_member(:foo, union_type, shape_ref)
+            member_shape = MemberShape.new(target: StringShape.new)
+            subject.add_member(:foo, union_type, member_shape)
             expect(subject.member?(:foo)).to be(true)
           end
         end
 
         describe '#member' do
           it 'returns the member' do
-            shape_ref = MemberShape.new(target: StringShape.new)
-            subject.add_member(:foo, union_type, shape_ref)
+            member_shape = MemberShape.new(target: StringShape.new)
+            subject.add_member(:foo, union_type, member_shape)
             expect(subject.member(:foo)).to be_kind_of(MemberShape)
           end
         end
 
         describe '#member_type?' do
           it 'returns true if member type exists' do
-            shape_ref = MemberShape.new(target: StringShape.new)
-            subject.add_member(:foo, union_type, shape_ref)
+            member_shape = MemberShape.new(target: StringShape.new)
+            subject.add_member(:foo, union_type, member_shape)
             expect(subject.member_type?(:foo)).to be(true)
           end
         end
 
         describe '#member_type' do
           it 'returns the member type' do
-            shape_ref = MemberShape.new(target: StringShape.new)
-            subject.add_member(:foo, union_type, shape_ref)
+            member_shape = MemberShape.new(target: StringShape.new)
+            subject.add_member(:foo, union_type, member_shape)
             expect(subject.member_type(:foo)).to eq(union_type)
           end
         end
 
         describe '#member_by_type?' do
           it 'returns true if member by type exists' do
-            shape_ref = MemberShape.new(target: StringShape.new)
-            subject.add_member(:foo, union_type, shape_ref)
+            member_shape = MemberShape.new(target: StringShape.new)
+            subject.add_member(:foo, union_type, member_shape)
             expect(subject.member_by_type?(union_type)).to be(true)
           end
         end
 
         describe '#member_by_type' do
           it 'returns the member by type' do
-            shape_ref = MemberShape.new(target: StringShape.new)
-            subject.add_member(:foo, union_type, shape_ref)
-            expect(subject.member_by_type(union_type)).to eq([:foo, shape_ref])
+            member_shape = MemberShape.new(target: StringShape.new)
+            subject.add_member(:foo, union_type, member_shape)
+            expect(subject.member_by_type(union_type)).to eq([:foo, member_shape])
           end
         end
       end
diff --git a/gems/smithy-xml/lib/smithy-xml/builder.rb b/gems/smithy-xml/lib/smithy-xml/builder.rb
index 83d1f87a4..c012f818e 100644
--- a/gems/smithy-xml/lib/smithy-xml/builder.rb
+++ b/gems/smithy-xml/lib/smithy-xml/builder.rb
@@ -54,27 +54,27 @@ def list(name, shape, values)
       end
 
       def map(name, shape, values)
-        key_ref = shape.target.key
-        value_ref = shape.target.value
+        key_shape = shape.target.key
+        value_shape = shape.target.value
         if flat?(shape)
-          resolve_flat(name, shape, values, key_ref, value_ref)
+          resolve_flat(name, shape, values, key_shape, value_shape)
         else
           node(name, shape) do
             values.each do |key, value|
               node('entry', MemberShape.new(target: MapShape.new)) do
-                build_shape(location_name(key_ref, 'key'), key_ref, key)
-                build_shape(location_name(value_ref, 'value'), value_ref, value)
+                build_shape(location_name(key_shape, 'key'), key_shape, key)
+                build_shape(location_name(value_shape, 'value'), value_shape, value)
               end
             end
           end
         end
       end
 
-      def resolve_flat(name, shape, values, key_ref, value_ref)
+      def resolve_flat(name, shape, values, key_shape, value_shape)
         values.each do |key, value|
           node(name, shape) do
-            build_shape(location_name(key_ref, 'key'), key_ref, key)
-            build_shape(location_name(value_ref, 'value'), value_ref, value)
+            build_shape(location_name(key_shape, 'key'), key_shape, key)
+            build_shape(location_name(value_shape, 'value'), value_shape, value)
           end
         end
       end
diff --git a/gems/smithy-xml/lib/smithy-xml/parser/stack.rb b/gems/smithy-xml/lib/smithy-xml/parser/stack.rb
index 97f45614b..979b4b614 100644
--- a/gems/smithy-xml/lib/smithy-xml/parser/stack.rb
+++ b/gems/smithy-xml/lib/smithy-xml/parser/stack.rb
@@ -22,7 +22,7 @@ def start_element(name)
 
         def attr(name, value)
           if name.to_s == 'encoding' && value.to_s == 'base64'
-            @frame = BlobFrame.new(name, @frame.parent, @frame.ref)
+            @frame = BlobFrame.new(name, @frame.parent, @frame.shape)
           else
             # don't try to parse shapes from xml namespace
             return if name.to_s == 'xmlns'

From cd1c965373f19d7a395ebe6c508f406f2190b7bf Mon Sep 17 00:00:00 2001
From: Juli Tera <terajul@amazon.com>
Date: Fri, 5 Jun 2026 09:16:35 -0700
Subject: [PATCH 22/23] Fix XML codec RBS Array type

---
 gems/smithy-xml/sig/smithy-xml/codec.rbs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gems/smithy-xml/sig/smithy-xml/codec.rbs b/gems/smithy-xml/sig/smithy-xml/codec.rbs
index 638f8bbca..b5f222ae5 100644
--- a/gems/smithy-xml/sig/smithy-xml/codec.rbs
+++ b/gems/smithy-xml/sig/smithy-xml/codec.rbs
@@ -1,7 +1,7 @@
 module Smithy
   module Xml
     class Codec
-      def build: (Schema::Shapes::Shape shape, Object data, ?Array? output) -> (nil | String)
+      def build: (Schema::Shapes::Shape shape, Object data, ?Array[String]? output) -> (nil | String)
       def parse: (Schema::Shapes::Shape shape, String bytes, ?Object ?result) -> Object?
     end
   end

From 5d6868d262b8804fb3ada5090274945375cbffd1 Mon Sep 17 00:00:00 2001
From: Juli Tera <terajul@amazon.com>
Date: Mon, 15 Jun 2026 11:48:46 -0700
Subject: [PATCH 23/23] Feeback - reword method

---
 gems/smithy-xml/lib/smithy-xml/builder.rb | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/gems/smithy-xml/lib/smithy-xml/builder.rb b/gems/smithy-xml/lib/smithy-xml/builder.rb
index c012f818e..62f143f71 100644
--- a/gems/smithy-xml/lib/smithy-xml/builder.rb
+++ b/gems/smithy-xml/lib/smithy-xml/builder.rb
@@ -57,7 +57,7 @@ def map(name, shape, values)
         key_shape = shape.target.key
         value_shape = shape.target.value
         if flat?(shape)
-          resolve_flat(name, shape, values, key_shape, value_shape)
+          flat_map_entries(name, shape, values, key_shape, value_shape)
         else
           node(name, shape) do
             values.each do |key, value|
@@ -70,7 +70,7 @@ def map(name, shape, values)
         end
       end
 
-      def resolve_flat(name, shape, values, key_shape, value_shape)
+      def flat_map_entries(name, shape, values, key_shape, value_shape)
         values.each do |key, value|
           node(name, shape) do
             build_shape(location_name(key_shape, 'key'), key_shape, key)