diff --git a/lib/ginny/models/mod.rb b/lib/ginny/models/mod.rb
new file mode 100644
index 0000000..c70679a
--- /dev/null
+++ b/lib/ginny/models/mod.rb
@@ -0,0 +1,51 @@
+module Ginny
+  # Used to generate a [module](https://ruby-doc.org/core-2.6.5/Module.html).
+  class Mod
+
+    # List of modules to declare the module inside. Only one is required.
+    # @return [String]
+    attr_accessor :modules
+    # Description of the module. [Markdown](https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet) is supported.
+    # @return [String]
+    attr_accessor :description
+    # String to write into the body of the module.
+    # @return [String]
+    attr_accessor :body
+
+    # @return [void]
+    def initialize()
+      self.modules = []
+    end
+
+    # Constructor for a Func. Use `create`, not `new`.
+    #
+    # @param args [Hash<Symbol>]
+    # @return [Ginny::Func]
+    def self.create(args = {})
+      m = Ginny::Mod.new()
+      m.modules     = args[:modules] unless args[:modules].nil?
+      m.description = args[:description]
+      m.body        = args[:body]
+      return m
+    end
+
+    # Write generated code out to a file.
+    #
+    # @param folder [String]
+    # @param file [String]
+    # @return [String]
+    def generate(folder = ".", file: nil)
+      name = file.nil? ? self.file_name() : file
+      path = File.join(File.expand_path(folder), name)
+      File.open(path, "a") { |f| f.write(self.render() + "\n") }
+      return path
+    end
+
+    # Return generated code as a string.
+    #
+    # @return [String]
+    def render()
+      return Ginny.mod(self.body, self.modules)
+    end
+  end
+end
diff --git a/test/ginny/mod_class_test.rb b/test/ginny/mod_class_test.rb
new file mode 100644
index 0000000..60c7abf
--- /dev/null
+++ b/test/ginny/mod_class_test.rb
@@ -0,0 +1,40 @@
+require "test_helper"
+
+class ModClassTest < Minitest::Test
+
+  def test_mod_without_body
+    want = <<~RUBY.strip
+      module Level1
+        module Level2
+        end
+      end
+    RUBY
+    have = Ginny::Mod.create(
+      modules: ["Level1", "Level2"],
+    ).render()
+    assert_equal(want, have)
+  end
+
+  def test_mod_with_body
+    want = <<~RUBY.strip
+      module Level1
+        module Level2
+          # Say hello.
+          # @return [String]
+          def greet()
+          end
+        end
+      end
+    RUBY
+    have = Ginny::Mod.create(
+      modules: ["Level1", "Level2"],
+      body: Ginny::Func.create(
+        name: "greet",
+        return_type: "String",
+        description: "Say hello.",
+      ).render(),
+    ).render()
+    assert_equal(want, have)
+  end
+
+end