diff --git a/lib/decode/language/ruby/parser.rb b/lib/decode/language/ruby/parser.rb
index 869edcd..a556872 100644
--- a/lib/decode/language/ruby/parser.rb
+++ b/lib/decode/language/ruby/parser.rb
@@ -163,15 +163,36 @@ def walk_definitions(node, parent = nil, source = nil, &block)
 						
 						yield definition
 					when :constant_write_node
-						definition = Constant.new(node.name,
-							comments: comments_for(node),
-							parent: parent,
-							node: node,
-							language: @language,
-						)
-						
-						store_definition(parent, node.name, definition)
-						yield definition
+						if super_class = struct_super_class_for(node.value)
+							definition = Class.new([node.name],
+								super_class: super_class,
+								visibility: :public,
+								comments: comments_for(node),
+								parent: parent,
+								node: node,
+								language: @language,
+								source: source,
+							)
+							
+							store_definition(parent, node.name, definition)
+							yield definition
+							
+							if body = node.value.block&.body
+								with_visibility do
+									walk_definitions(body, definition, source, &block)
+								end
+							end
+						else
+							definition = Constant.new(node.name,
+								comments: comments_for(node),
+								parent: parent,
+								node: node,
+								language: @language,
+							)
+							
+							store_definition(parent, node.name, definition)
+							yield definition
+						end
 					when :call_node
 						name = node.name
 						
@@ -506,6 +527,24 @@ def receiver_for(node)
 					end
 				end
 				
+				def struct_super_class_for(node)
+					return unless node&.type == :call_node
+					return unless node.block
+					
+					case node.receiver&.type
+					when :constant_read_node
+						receiver_name = node.receiver.name.to_s
+					when :constant_path_node
+						receiver_name = nested_name_for(node.receiver)
+					end
+					
+					if receiver_name == "Struct" && node.name == :new
+						return "Struct"
+					elsif receiver_name == "Data" && node.name == :define
+						return "Data"
+					end
+				end
+				
 				def singleton_name_for(node)
 					case node.expression.type
 					when :self_node
diff --git a/releases.md b/releases.md
index 137f8b3..cc22c3b 100644
--- a/releases.md
+++ b/releases.md
@@ -1,5 +1,9 @@
 # Releases
 
+## Unreleased
+
+  - Add support for indexing methods inside `Struct.new` and `Data.define` assignment blocks.
+
 ## v0.27.0
 
     - Add `decode:documentation:markdown` bake task for generating LLM-optimized Markdown documentation.
diff --git a/test/decode/language/ruby/.fixtures/data_struct.rb b/test/decode/language/ruby/.fixtures/data_struct.rb
new file mode 100644
index 0000000..c1ffb4e
--- /dev/null
+++ b/test/decode/language/ruby/.fixtures/data_struct.rb
@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+# The context object.
+Context = Struct.new(:arguments, keyword_init: true) do
+	# Build a context.
+	def self.for(arguments)
+	end
+	
+	# The completed words.
+	def words
+	end
+end
+
+module Types
+	# The request object.
+	Request = Data.define(:arguments) do
+		# Build a request.
+		def self.for(arguments)
+		end
+		
+		# The completed words.
+		def words
+		end
+	end
+end
diff --git a/test/decode/language/ruby/parser.rb b/test/decode/language/ruby/parser.rb
index 8feeb3b..2cdf7cd 100644
--- a/test/decode/language/ruby/parser.rb
+++ b/test/decode/language/ruby/parser.rb
@@ -196,6 +196,60 @@
 		end
 	end
 	
+	with "Struct.new and Data.define assignments" do
+		let(:path) {File.expand_path(".fixtures/data_struct.rb", __dir__)}
+		
+		it "treats Struct.new assignments as class-like containers" do
+			context = definitions.find{|definition| definition.full_path == [:Context]}
+			
+			expect(context).to be_a(Decode::Language::Ruby::Class)
+			expect(context).to have_attributes(
+				short_form: be == "class Context",
+				long_form: be == "class Context < Struct",
+				comments: be == ["The context object."],
+			)
+			expect(context).to be(:container?)
+		end
+		
+		it "extracts methods from Struct.new assignment blocks" do
+			methods = definitions.select{|definition| definition.parent&.name == :Context}
+			
+			expect(methods.collect(&:short_form)).to be == [
+				"def self.for",
+				"def words",
+			]
+			expect(methods.collect(&:full_path)).to be == [
+				[:Context, :for],
+				[:Context, :words],
+			]
+		end
+		
+		it "treats Data.define assignments as class-like containers" do
+			request = definitions.find{|definition| definition.full_path == [:Types, :Request]}
+			
+			expect(request).to be_a(Decode::Language::Ruby::Class)
+			expect(request).to have_attributes(
+				short_form: be == "class Request",
+				long_form: be == "class Types::Request < Data",
+				comments: be == ["The request object."],
+			)
+			expect(request).to be(:container?)
+		end
+		
+		it "extracts methods from Data.define assignment blocks" do
+			methods = definitions.select{|definition| definition.parent&.name == :Request}
+			
+			expect(methods.collect(&:short_form)).to be == [
+				"def self.for",
+				"def words",
+			]
+			expect(methods.collect(&:full_path)).to be == [
+				[:Types, :Request, :for],
+				[:Types, :Request, :words],
+			]
+		end
+	end
+	
 	with "attributes" do
 		let(:path) {File.expand_path(".fixtures/attributes.rb", __dir__)}