diff --git a/lib/protoboeuf/codegen.rb b/lib/protoboeuf/codegen.rb
index af9b1e1..cd692d1 100644
--- a/lib/protoboeuf/codegen.rb
+++ b/lib/protoboeuf/codegen.rb
@@ -88,8 +88,7 @@ def result(message, toplevel_enums, generate_types:, requires:, syntax:, options
         end
       end
 
-      attr_reader :message, :fields, :oneof_fields, :syntax
-      attr_reader :optional_fields, :enum_field_types
+      attr_reader :message, :fields, :oneof_fields, :syntax, :optional_fields, :enum_field_types, :oneof_json_names
 
       def initialize(message, toplevel_enums, generate_types:, requires:, syntax:, options:)
         @message = message
@@ -109,6 +108,7 @@ def initialize(message, toplevel_enums, generate_types:, requires:, syntax:, opt
         @oneof_fields = []
         @enum_fields = []
         @oneof_selection_fields = []
+        @oneof_json_names = {}
 
         optional_field_count = 0
 
@@ -123,6 +123,7 @@ def initialize(message, toplevel_enums, generate_types:, requires:, syntax:, opt
             optional_field_count += 1
           elsif field.has_oneof_index?
             (@oneof_fields[field.oneof_index] ||= []) << field
+            @oneof_json_names[field.name] = field.json_name
           elsif field.type == :TYPE_ENUM
             @enum_fields << field
           else
@@ -164,27 +165,46 @@ def conversion
           field.has_oneof_index? && !field.optional?
         end
 
-        oneofs = @oneof_selection_fields.map do |field|
-          "send(#{field.name.dump}).tap { |f| result[f.to_sym] = send(f) if f }"
-        end
+        oneofs = @oneof_selection_fields
 
         <<~RUBY
           #{type_signature(returns: "T::Hash[Symbol, T.untyped]")}
           def to_h
             result = {}
-            #{(oneofs + fields.map { |field| convert_field(field) }).join("\n")}
+            #{oneofs.map { |oneof| hash_assignment_for_oneof(oneof, json: false) }.join("\n")}
+            #{fields.map { |field| hash_assignment_for_field(field, json: false) }.join("\n")}
+            result
+          end
+
+          #{type_signature(params: "T::Hash[T.untyped, T.untyped]", returns: "T::Hash[Symbol, T.untyped]")}
+          def as_json(options = {})
+            result = {}
+            #{oneofs.map { |oneof| hash_assignment_for_oneof(oneof, json: true) }.join("\n")}
+            #{fields.map { |field| hash_assignment_for_field(field, json: true) }.join("\n")}
             result
           end
+
+          def to_json(options = {})
+            require 'json'
+            JSON.dump(as_json(options))
+          end
         RUBY
       end
 
-      def convert_field(field)
+      def hash_assignment_for_oneof(oneof, json: false)
+        "send(field.name.dump).tap { |f| result[f.to_sym] = send(f) if f }"
+      end
+
+      def hash_assignment_for_field(field, json: false)
+        key_string = "#{(json ? field.json_name : field.name).dump}.to_sym"
+        recurse_with = json ? "as_json" : "to_h"
+
         if field.repeated?
-          "result['#{field.name}'.to_sym] = #{iv_name(field)}"
+          "result[#{key_string}] = #{iv_name(field)}"
         elsif field.type == :TYPE_MESSAGE
-          "result['#{field.name}'.to_sym] = #{iv_name(field)}.to_h"
+          "result[#{key_string}] = #{iv_name(field)}.#{recurse_with}"
         else
-          "result['#{field.name}'.to_sym] = #{iv_name(field)}"
+          "result[#{key_string}] = #{iv_name(field)}"
         end
       end
 
@@ -782,6 +802,7 @@ def initialize_code
         initialize_type_signature(fields) +
           "def initialize(" + initialize_signature + ")\n" +
           init_bitmask(message) +
+          init_oneof_json_names(message) +
           initialize_oneofs +
           fields.map { |field|
             if field.has_oneof_index? && !field.optional?
@@ -910,6 +931,13 @@ def iv_name(field)
         "@#{field.name}"
       end
 
+      # Our generated code needs to keep a hash of oneof field names to their corresponding JSON name.  This is
+      # unnecessary for other field types since we can access the json_name upon code generation, but the particular
+      # oneof field isn't known until runtime.
+      def oneof_json_name(field)
+        "@_oneof_json_names[:#{field.name}]"
+      end
+
       def initialize_required_field(field)
         <<~RUBY
           #{bounds_check(field, lvar_read(field)).chomp}
@@ -1650,6 +1678,18 @@ def init_bitmask(msg)
         end
       end
 
+      ONEOF_JSON_NAMES = ERB.new(<<~RUBY, trim_mode: "-")
+        @_oneof_json_names = {
+          <%- oneof_json_names.each do |field_name, json_name| -%>
+          :<%= field_name.dump %> => <%= json_name.dump %>,
+          <%- end %>
+        }
+      RUBY
+
+      def init_oneof_json_names(_msg)
+        ONEOF_JSON_NAMES.result(binding)
+      end
+
       def set_bitmask(field) # rubocop:disable Naming/AccessorMethodName
         i = @optional_field_bit_lut.fetch(field.number) || raise("optional field should have a bit")
         "@_bitmask |= #{format("%#018x", 1 << i)}"
diff --git a/lib/protoboeuf/decorated_field.rb b/lib/protoboeuf/decorated_field.rb
index a6255c9..5de14a3 100644
--- a/lib/protoboeuf/decorated_field.rb
+++ b/lib/protoboeuf/decorated_field.rb
@@ -8,7 +8,16 @@ class DecoratedField
 
   extend Forwardable
 
-  def_delegators :@original_field, :name, :label, :type_name, :type, :number, :options, :oneof_index, :has_oneof_index?
+  def_delegators :@original_field,
+    :name,
+    :label,
+    :type_name,
+    :type,
+    :number,
+    :options,
+    :oneof_index,
+    :has_oneof_index?,
+    :json_name
 
   def initialize(field:, message:, syntax:)
     @original_field = field
diff --git a/lib/protoboeuf/google/protobuf/any.rb b/lib/protoboeuf/google/protobuf/any.rb
index 5977153..906cff6 100644
--- a/lib/protoboeuf/google/protobuf/any.rb
+++ b/lib/protoboeuf/google/protobuf/any.rb
@@ -28,6 +28,8 @@ def value=(v)
         end
 
         def initialize(type_url: "", value: "")
+          @_oneof_json_names = {}
+
           @type_url = type_url
 
           @value = value
@@ -553,10 +555,24 @@ def _encode(buff)
 
         def to_h
           result = {}
+
           result["type_url".to_sym] = @type_url
           result["value".to_sym] = @value
           result
         end
+
+        def as_json(options = {})
+          result = {}
+
+          result["typeUrl".to_sym] = @type_url
+          result["value".to_sym] = @value
+          result
+        end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
     end
   end
diff --git a/lib/protoboeuf/google/protobuf/boolvalue.rb b/lib/protoboeuf/google/protobuf/boolvalue.rb
index ed3424c..cdf4860 100644
--- a/lib/protoboeuf/google/protobuf/boolvalue.rb
+++ b/lib/protoboeuf/google/protobuf/boolvalue.rb
@@ -22,6 +22,8 @@ def value=(v)
         end
 
         def initialize(value: false)
+          @_oneof_json_names = {}
+
           @value = value
         end
 
@@ -349,9 +351,22 @@ def _encode(buff)
 
         def to_h
           result = {}
+
+          result["value".to_sym] = @value
+          result
+        end
+
+        def as_json(options = {})
+          result = {}
+
           result["value".to_sym] = @value
           result
         end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
     end
   end
diff --git a/lib/protoboeuf/google/protobuf/bytesvalue.rb b/lib/protoboeuf/google/protobuf/bytesvalue.rb
index 05905a2..bf9a2ad 100644
--- a/lib/protoboeuf/google/protobuf/bytesvalue.rb
+++ b/lib/protoboeuf/google/protobuf/bytesvalue.rb
@@ -22,6 +22,8 @@ def value=(v)
         end
 
         def initialize(value: "")
+          @_oneof_json_names = {}
+
           @value = value
         end
 
@@ -408,9 +410,22 @@ def _encode(buff)
 
         def to_h
           result = {}
+
+          result["value".to_sym] = @value
+          result
+        end
+
+        def as_json(options = {})
+          result = {}
+
           result["value".to_sym] = @value
           result
         end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
     end
   end
diff --git a/lib/protoboeuf/google/protobuf/descriptor.rb b/lib/protoboeuf/google/protobuf/descriptor.rb
index af152fe..108f36c 100644
--- a/lib/protoboeuf/google/protobuf/descriptor.rb
+++ b/lib/protoboeuf/google/protobuf/descriptor.rb
@@ -67,6 +67,8 @@ def file=(v)
         end
 
         def initialize(file: [])
+          @_oneof_json_names = {}
+
           @file = file
         end
 
@@ -512,9 +514,22 @@ def _encode(buff)
 
         def to_h
           result = {}
+
+          result["file".to_sym] = @file
+          result
+        end
+
+        def as_json(options = {})
+          result = {}
+
           result["file".to_sym] = @file
           result
         end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
       class FileDescriptorProto
         def self.decode(buff)
@@ -648,6 +663,8 @@ def initialize(
         )
           @_bitmask = 0
 
+          @_oneof_json_names = {}
+
           if name == nil
             @name = ""
           else
@@ -3357,6 +3374,7 @@ def _encode(buff)
 
         def to_h
           result = {}
+
           result["name".to_sym] = @name
           result["package".to_sym] = @package
           result["dependency".to_sym] = @dependency
@@ -3372,6 +3390,30 @@ def to_h
           result["edition".to_sym] = @edition
           result
         end
+
+        def as_json(options = {})
+          result = {}
+
+          result["name".to_sym] = @name
+          result["package".to_sym] = @package
+          result["dependency".to_sym] = @dependency
+          result["publicDependency".to_sym] = @public_dependency
+          result["weakDependency".to_sym] = @weak_dependency
+          result["messageType".to_sym] = @message_type
+          result["enumType".to_sym] = @enum_type
+          result["service".to_sym] = @service
+          result["extension".to_sym] = @extension
+          result["options".to_sym] = @options.as_json
+          result["sourceCodeInfo".to_sym] = @source_code_info.as_json
+          result["syntax".to_sym] = @syntax
+          result["edition".to_sym] = @edition
+          result
+        end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
       class DescriptorProto
         def self.decode(buff)
@@ -3430,6 +3472,8 @@ def options=(v)
           def initialize(start: nil, end: nil, options: nil)
             @_bitmask = 0
 
+            @_oneof_json_names = {}
+
             if start == nil
               @start = 0
             else
@@ -4205,11 +4249,26 @@ def _encode(buff)
 
           def to_h
             result = {}
+
             result["start".to_sym] = @start
             result["end".to_sym] = @end
             result["options".to_sym] = @options.to_h
             result
           end
+
+          def as_json(options = {})
+            result = {}
+
+            result["start".to_sym] = @start
+            result["end".to_sym] = @end
+            result["options".to_sym] = @options.as_json
+            result
+          end
+
+          def to_json(options = {})
+            require "json"
+            JSON.dump(as_json(options))
+          end
         end
 
         class ReservedRange
@@ -4254,6 +4313,8 @@ def end=(v)
           def initialize(start: nil, end: nil)
             @_bitmask = 0
 
+            @_oneof_json_names = {}
+
             if start == nil
               @start = 0
             else
@@ -4840,10 +4901,24 @@ def _encode(buff)
 
           def to_h
             result = {}
+
             result["start".to_sym] = @start
             result["end".to_sym] = @end
             result
           end
+
+          def as_json(options = {})
+            result = {}
+
+            result["start".to_sym] = @start
+            result["end".to_sym] = @end
+            result
+          end
+
+          def to_json(options = {})
+            require "json"
+            JSON.dump(as_json(options))
+          end
         end
         # required field readers
 
@@ -4928,6 +5003,8 @@ def initialize(
         )
           @_bitmask = 0
 
+          @_oneof_json_names = {}
+
           if name == nil
             @name = ""
           else
@@ -7055,6 +7132,7 @@ def _encode(buff)
 
         def to_h
           result = {}
+
           result["name".to_sym] = @name
           result["field".to_sym] = @field
           result["extension".to_sym] = @extension
@@ -7067,6 +7145,27 @@ def to_h
           result["reserved_name".to_sym] = @reserved_name
           result
         end
+
+        def as_json(options = {})
+          result = {}
+
+          result["name".to_sym] = @name
+          result["field".to_sym] = @field
+          result["extension".to_sym] = @extension
+          result["nestedType".to_sym] = @nested_type
+          result["enumType".to_sym] = @enum_type
+          result["extensionRange".to_sym] = @extension_range
+          result["oneofDecl".to_sym] = @oneof_decl
+          result["options".to_sym] = @options.as_json
+          result["reservedRange".to_sym] = @reserved_range
+          result["reservedName".to_sym] = @reserved_name
+          result
+        end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
       class ExtensionRangeOptions
         def self.decode(buff)
@@ -7140,6 +7239,8 @@ def initialize(
           )
             @_bitmask = 0
 
+            @_oneof_json_names = {}
+
             if number == nil
               @number = 0
             else
@@ -8038,6 +8139,7 @@ def _encode(buff)
 
           def to_h
             result = {}
+
             result["number".to_sym] = @number
             result["full_name".to_sym] = @full_name
             result["type".to_sym] = @type
@@ -8045,6 +8147,22 @@ def to_h
             result["repeated".to_sym] = @repeated
             result
           end
+
+          def as_json(options = {})
+            result = {}
+
+            result["number".to_sym] = @number
+            result["fullName".to_sym] = @full_name
+            result["type".to_sym] = @type
+            result["reserved".to_sym] = @reserved
+            result["repeated".to_sym] = @repeated
+            result
+          end
+
+          def to_json(options = {})
+            require "json"
+            JSON.dump(as_json(options))
+          end
         end
         module VerificationState
           DECLARATION = 0
@@ -8108,6 +8226,8 @@ def initialize(
         )
           @_bitmask = 0
 
+          @_oneof_json_names = {}
+
           @uninterpreted_option = uninterpreted_option
 
           @declaration = declaration
@@ -9104,12 +9224,28 @@ def _encode(buff)
 
         def to_h
           result = {}
+
           result["uninterpreted_option".to_sym] = @uninterpreted_option
           result["declaration".to_sym] = @declaration
           result["features".to_sym] = @features.to_h
           result["verification".to_sym] = @verification
           result
         end
+
+        def as_json(options = {})
+          result = {}
+
+          result["uninterpretedOption".to_sym] = @uninterpreted_option
+          result["declaration".to_sym] = @declaration
+          result["features".to_sym] = @features.as_json
+          result["verification".to_sym] = @verification
+          result
+        end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
       class FieldDescriptorProto
         def self.decode(buff)
@@ -9319,6 +9455,8 @@ def initialize(
         )
           @_bitmask = 0
 
+          @_oneof_json_names = {}
+
           if name == nil
             @name = ""
           else
@@ -11243,6 +11381,7 @@ def _encode(buff)
 
         def to_h
           result = {}
+
           result["name".to_sym] = @name
           result["number".to_sym] = @number
           result["label".to_sym] = @label
@@ -11256,6 +11395,28 @@ def to_h
           result["proto3_optional".to_sym] = @proto3_optional
           result
         end
+
+        def as_json(options = {})
+          result = {}
+
+          result["name".to_sym] = @name
+          result["number".to_sym] = @number
+          result["label".to_sym] = @label
+          result["type".to_sym] = @type
+          result["typeName".to_sym] = @type_name
+          result["extendee".to_sym] = @extendee
+          result["defaultValue".to_sym] = @default_value
+          result["oneofIndex".to_sym] = @oneof_index
+          result["jsonName".to_sym] = @json_name
+          result["options".to_sym] = @options.as_json
+          result["proto3Optional".to_sym] = @proto3_optional
+          result
+        end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
       class OneofDescriptorProto
         def self.decode(buff)
@@ -11289,6 +11450,8 @@ def options=(v)
         def initialize(name: nil, options: nil)
           @_bitmask = 0
 
+          @_oneof_json_names = {}
+
           if name == nil
             @name = ""
           else
@@ -11876,10 +12039,24 @@ def _encode(buff)
 
         def to_h
           result = {}
+
           result["name".to_sym] = @name
           result["options".to_sym] = @options.to_h
           result
         end
+
+        def as_json(options = {})
+          result = {}
+
+          result["name".to_sym] = @name
+          result["options".to_sym] = @options.as_json
+          result
+        end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
       class EnumDescriptorProto
         def self.decode(buff)
@@ -11931,6 +12108,8 @@ def end=(v)
           def initialize(start: nil, end: nil)
             @_bitmask = 0
 
+            @_oneof_json_names = {}
+
             if start == nil
               @start = 0
             else
@@ -12517,10 +12696,24 @@ def _encode(buff)
 
           def to_h
             result = {}
+
+            result["start".to_sym] = @start
+            result["end".to_sym] = @end
+            result
+          end
+
+          def as_json(options = {})
+            result = {}
+
             result["start".to_sym] = @start
             result["end".to_sym] = @end
             result
           end
+
+          def to_json(options = {})
+            require "json"
+            JSON.dump(as_json(options))
+          end
         end
         # required field readers
 
@@ -12570,6 +12763,8 @@ def initialize(
         )
           @_bitmask = 0
 
+          @_oneof_json_names = {}
+
           if name == nil
             @name = ""
           else
@@ -13707,6 +13902,7 @@ def _encode(buff)
 
         def to_h
           result = {}
+
           result["name".to_sym] = @name
           result["value".to_sym] = @value
           result["options".to_sym] = @options.to_h
@@ -13714,6 +13910,22 @@ def to_h
           result["reserved_name".to_sym] = @reserved_name
           result
         end
+
+        def as_json(options = {})
+          result = {}
+
+          result["name".to_sym] = @name
+          result["value".to_sym] = @value
+          result["options".to_sym] = @options.as_json
+          result["reservedRange".to_sym] = @reserved_range
+          result["reservedName".to_sym] = @reserved_name
+          result
+        end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
       class EnumValueDescriptorProto
         def self.decode(buff)
@@ -13759,6 +13971,8 @@ def options=(v)
         def initialize(name: nil, number: nil, options: nil)
           @_bitmask = 0
 
+          @_oneof_json_names = {}
+
           if name == nil
             @name = ""
           else
@@ -14511,11 +14725,26 @@ def _encode(buff)
 
         def to_h
           result = {}
+
           result["name".to_sym] = @name
           result["number".to_sym] = @number
           result["options".to_sym] = @options.to_h
           result
         end
+
+        def as_json(options = {})
+          result = {}
+
+          result["name".to_sym] = @name
+          result["number".to_sym] = @number
+          result["options".to_sym] = @options.as_json
+          result
+        end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
       class ServiceDescriptorProto
         def self.decode(buff)
@@ -14555,6 +14784,8 @@ def options=(v)
         def initialize(name: nil, method: [], options: nil)
           @_bitmask = 0
 
+          @_oneof_json_names = {}
+
           if name == nil
             @name = ""
           else
@@ -15340,11 +15571,26 @@ def _encode(buff)
 
         def to_h
           result = {}
+
           result["name".to_sym] = @name
           result["method".to_sym] = @method
           result["options".to_sym] = @options.to_h
           result
         end
+
+        def as_json(options = {})
+          result = {}
+
+          result["name".to_sym] = @name
+          result["method".to_sym] = @method
+          result["options".to_sym] = @options.as_json
+          result
+        end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
       class MethodDescriptorProto
         def self.decode(buff)
@@ -15413,6 +15659,8 @@ def initialize(
         )
           @_bitmask = 0
 
+          @_oneof_json_names = {}
+
           if name == nil
             @name = ""
           else
@@ -16478,6 +16726,7 @@ def _encode(buff)
 
         def to_h
           result = {}
+
           result["name".to_sym] = @name
           result["input_type".to_sym] = @input_type
           result["output_type".to_sym] = @output_type
@@ -16486,6 +16735,23 @@ def to_h
           result["server_streaming".to_sym] = @server_streaming
           result
         end
+
+        def as_json(options = {})
+          result = {}
+
+          result["name".to_sym] = @name
+          result["inputType".to_sym] = @input_type
+          result["outputType".to_sym] = @output_type
+          result["options".to_sym] = @options.as_json
+          result["clientStreaming".to_sym] = @client_streaming
+          result["serverStreaming".to_sym] = @server_streaming
+          result
+        end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
       class FileOptions
         def self.decode(buff)
@@ -16697,6 +16963,8 @@ def initialize(
         )
           @_bitmask = 0
 
+          @_oneof_json_names = {}
+
           if java_package == nil
             @java_package = ""
           else
@@ -19719,6 +19987,7 @@ def _encode(buff)
 
         def to_h
           result = {}
+
           result["java_package".to_sym] = @java_package
           result["java_outer_classname".to_sym] = @java_outer_classname
           result["java_multiple_files".to_sym] = @java_multiple_files
@@ -19744,6 +20013,40 @@ def to_h
           result["uninterpreted_option".to_sym] = @uninterpreted_option
           result
         end
+
+        def as_json(options = {})
+          result = {}
+
+          result["javaPackage".to_sym] = @java_package
+          result["javaOuterClassname".to_sym] = @java_outer_classname
+          result["javaMultipleFiles".to_sym] = @java_multiple_files
+          result[
+            "javaGenerateEqualsAndHash".to_sym
+          ] = @java_generate_equals_and_hash
+          result["javaStringCheckUtf8".to_sym] = @java_string_check_utf8
+          result["optimizeFor".to_sym] = @optimize_for
+          result["goPackage".to_sym] = @go_package
+          result["ccGenericServices".to_sym] = @cc_generic_services
+          result["javaGenericServices".to_sym] = @java_generic_services
+          result["pyGenericServices".to_sym] = @py_generic_services
+          result["deprecated".to_sym] = @deprecated
+          result["ccEnableArenas".to_sym] = @cc_enable_arenas
+          result["objcClassPrefix".to_sym] = @objc_class_prefix
+          result["csharpNamespace".to_sym] = @csharp_namespace
+          result["swiftPrefix".to_sym] = @swift_prefix
+          result["phpClassPrefix".to_sym] = @php_class_prefix
+          result["phpNamespace".to_sym] = @php_namespace
+          result["phpMetadataNamespace".to_sym] = @php_metadata_namespace
+          result["rubyPackage".to_sym] = @ruby_package
+          result["features".to_sym] = @features.as_json
+          result["uninterpretedOption".to_sym] = @uninterpreted_option
+          result
+        end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
       class MessageOptions
         def self.decode(buff)
@@ -19819,6 +20122,8 @@ def initialize(
         )
           @_bitmask = 0
 
+          @_oneof_json_names = {}
+
           if message_set_wire_format == nil
             @message_set_wire_format = false
           else
@@ -20908,6 +21213,7 @@ def _encode(buff)
 
         def to_h
           result = {}
+
           result["message_set_wire_format".to_sym] = @message_set_wire_format
           result[
             "no_standard_descriptor_accessor".to_sym
@@ -20921,6 +21227,28 @@ def to_h
           result["uninterpreted_option".to_sym] = @uninterpreted_option
           result
         end
+
+        def as_json(options = {})
+          result = {}
+
+          result["messageSetWireFormat".to_sym] = @message_set_wire_format
+          result[
+            "noStandardDescriptorAccessor".to_sym
+          ] = @no_standard_descriptor_accessor
+          result["deprecated".to_sym] = @deprecated
+          result["mapEntry".to_sym] = @map_entry
+          result[
+            "deprecatedLegacyJsonFieldConflicts".to_sym
+          ] = @deprecated_legacy_json_field_conflicts
+          result["features".to_sym] = @features.as_json
+          result["uninterpretedOption".to_sym] = @uninterpreted_option
+          result
+        end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
       class FieldOptions
         def self.decode(buff)
@@ -20964,6 +21292,8 @@ def value=(v)
           def initialize(edition: nil, value: nil)
             @_bitmask = 0
 
+            @_oneof_json_names = {}
+
             if edition == nil
               @edition = 0
             else
@@ -21527,10 +21857,24 @@ def _encode(buff)
 
           def to_h
             result = {}
+
+            result["edition".to_sym] = @edition
+            result["value".to_sym] = @value
+            result
+          end
+
+          def as_json(options = {})
+            result = {}
+
             result["edition".to_sym] = @edition
             result["value".to_sym] = @value
             result
           end
+
+          def to_json(options = {})
+            require "json"
+            JSON.dump(as_json(options))
+          end
         end
 
         class FeatureSupport
@@ -21592,6 +21936,8 @@ def initialize(
           )
             @_bitmask = 0
 
+            @_oneof_json_names = {}
+
             if edition_introduced == nil
               @edition_introduced = 0
             else
@@ -22476,12 +22822,28 @@ def _encode(buff)
 
           def to_h
             result = {}
+
             result["edition_introduced".to_sym] = @edition_introduced
             result["edition_deprecated".to_sym] = @edition_deprecated
             result["deprecation_warning".to_sym] = @deprecation_warning
             result["edition_removed".to_sym] = @edition_removed
             result
           end
+
+          def as_json(options = {})
+            result = {}
+
+            result["editionIntroduced".to_sym] = @edition_introduced
+            result["editionDeprecated".to_sym] = @edition_deprecated
+            result["deprecationWarning".to_sym] = @deprecation_warning
+            result["editionRemoved".to_sym] = @edition_removed
+            result
+          end
+
+          def to_json(options = {})
+            require "json"
+            JSON.dump(as_json(options))
+          end
         end
         module CType
           STRING = 0
@@ -22710,6 +23072,8 @@ def initialize(
         )
           @_bitmask = 0
 
+          @_oneof_json_names = {}
+
           if ctype == nil
             @ctype = 0
           else
@@ -24927,6 +25291,7 @@ def _encode(buff)
 
         def to_h
           result = {}
+
           result["ctype".to_sym] = @ctype
           result["packed".to_sym] = @packed
           result["jstype".to_sym] = @jstype
@@ -24943,6 +25308,31 @@ def to_h
           result["uninterpreted_option".to_sym] = @uninterpreted_option
           result
         end
+
+        def as_json(options = {})
+          result = {}
+
+          result["ctype".to_sym] = @ctype
+          result["packed".to_sym] = @packed
+          result["jstype".to_sym] = @jstype
+          result["lazy".to_sym] = @lazy
+          result["unverifiedLazy".to_sym] = @unverified_lazy
+          result["deprecated".to_sym] = @deprecated
+          result["weak".to_sym] = @weak
+          result["debugRedact".to_sym] = @debug_redact
+          result["retention".to_sym] = @retention
+          result["targets".to_sym] = @targets
+          result["editionDefaults".to_sym] = @edition_defaults
+          result["features".to_sym] = @features.as_json
+          result["featureSupport".to_sym] = @feature_support.as_json
+          result["uninterpretedOption".to_sym] = @uninterpreted_option
+          result
+        end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
       class OneofOptions
         def self.decode(buff)
@@ -24975,6 +25365,8 @@ def features=(v)
         def initialize(features: nil, uninterpreted_option: [])
           @_bitmask = 0
 
+          @_oneof_json_names = {}
+
           if features == nil
             @features = nil
           else
@@ -25612,10 +26004,24 @@ def _encode(buff)
 
         def to_h
           result = {}
+
           result["features".to_sym] = @features.to_h
           result["uninterpreted_option".to_sym] = @uninterpreted_option
           result
         end
+
+        def as_json(options = {})
+          result = {}
+
+          result["features".to_sym] = @features.as_json
+          result["uninterpretedOption".to_sym] = @uninterpreted_option
+          result
+        end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
       class EnumOptions
         def self.decode(buff)
@@ -25675,6 +26081,8 @@ def initialize(
         )
           @_bitmask = 0
 
+          @_oneof_json_names = {}
+
           if allow_alias == nil
             @allow_alias = false
           else
@@ -26584,6 +26992,7 @@ def _encode(buff)
 
         def to_h
           result = {}
+
           result["allow_alias".to_sym] = @allow_alias
           result["deprecated".to_sym] = @deprecated
           result[
@@ -26593,6 +27002,24 @@ def to_h
           result["uninterpreted_option".to_sym] = @uninterpreted_option
           result
         end
+
+        def as_json(options = {})
+          result = {}
+
+          result["allowAlias".to_sym] = @allow_alias
+          result["deprecated".to_sym] = @deprecated
+          result[
+            "deprecatedLegacyJsonFieldConflicts".to_sym
+          ] = @deprecated_legacy_json_field_conflicts
+          result["features".to_sym] = @features.as_json
+          result["uninterpretedOption".to_sym] = @uninterpreted_option
+          result
+        end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
       class EnumValueOptions
         def self.decode(buff)
@@ -26652,6 +27079,8 @@ def initialize(
         )
           @_bitmask = 0
 
+          @_oneof_json_names = {}
+
           if deprecated == nil
             @deprecated = false
           else
@@ -27658,6 +28087,7 @@ def _encode(buff)
 
         def to_h
           result = {}
+
           result["deprecated".to_sym] = @deprecated
           result["features".to_sym] = @features.to_h
           result["debug_redact".to_sym] = @debug_redact
@@ -27665,6 +28095,22 @@ def to_h
           result["uninterpreted_option".to_sym] = @uninterpreted_option
           result
         end
+
+        def as_json(options = {})
+          result = {}
+
+          result["deprecated".to_sym] = @deprecated
+          result["features".to_sym] = @features.as_json
+          result["debugRedact".to_sym] = @debug_redact
+          result["featureSupport".to_sym] = @feature_support.as_json
+          result["uninterpretedOption".to_sym] = @uninterpreted_option
+          result
+        end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
       class ServiceOptions
         def self.decode(buff)
@@ -27704,6 +28150,8 @@ def deprecated=(v)
         def initialize(features: nil, deprecated: nil, uninterpreted_option: [])
           @_bitmask = 0
 
+          @_oneof_json_names = {}
+
           if features == nil
             @features = nil
           else
@@ -28433,11 +28881,26 @@ def _encode(buff)
 
         def to_h
           result = {}
+
           result["features".to_sym] = @features.to_h
           result["deprecated".to_sym] = @deprecated
           result["uninterpreted_option".to_sym] = @uninterpreted_option
           result
         end
+
+        def as_json(options = {})
+          result = {}
+
+          result["features".to_sym] = @features.as_json
+          result["deprecated".to_sym] = @deprecated
+          result["uninterpretedOption".to_sym] = @uninterpreted_option
+          result
+        end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
       class MethodOptions
         def self.decode(buff)
@@ -28513,6 +28976,8 @@ def initialize(
         )
           @_bitmask = 0
 
+          @_oneof_json_names = {}
+
           if deprecated == nil
             @deprecated = false
           else
@@ -29403,12 +29868,28 @@ def _encode(buff)
 
         def to_h
           result = {}
+
           result["deprecated".to_sym] = @deprecated
           result["idempotency_level".to_sym] = @idempotency_level
           result["features".to_sym] = @features.to_h
           result["uninterpreted_option".to_sym] = @uninterpreted_option
           result
         end
+
+        def as_json(options = {})
+          result = {}
+
+          result["deprecated".to_sym] = @deprecated
+          result["idempotencyLevel".to_sym] = @idempotency_level
+          result["features".to_sym] = @features.as_json
+          result["uninterpretedOption".to_sym] = @uninterpreted_option
+          result
+        end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
       class UninterpretedOption
         def self.decode(buff)
@@ -29441,6 +29922,8 @@ def is_extension=(v)
           end
 
           def initialize(name_part: "", is_extension: false)
+            @_oneof_json_names = {}
+
             @name_part = name_part
 
             @is_extension = is_extension
@@ -29913,10 +30396,24 @@ def _encode(buff)
 
           def to_h
             result = {}
+
             result["name_part".to_sym] = @name_part
             result["is_extension".to_sym] = @is_extension
             result
           end
+
+          def as_json(options = {})
+            result = {}
+
+            result["namePart".to_sym] = @name_part
+            result["isExtension".to_sym] = @is_extension
+            result
+          end
+
+          def to_json(options = {})
+            require "json"
+            JSON.dump(as_json(options))
+          end
         end
         # required field readers
 
@@ -29995,6 +30492,8 @@ def initialize(
         )
           @_bitmask = 0
 
+          @_oneof_json_names = {}
+
           @name = name
 
           if identifier_value == nil
@@ -31287,6 +31786,7 @@ def _encode(buff)
 
         def to_h
           result = {}
+
           result["name".to_sym] = @name
           result["identifier_value".to_sym] = @identifier_value
           result["positive_int_value".to_sym] = @positive_int_value
@@ -31296,6 +31796,24 @@ def to_h
           result["aggregate_value".to_sym] = @aggregate_value
           result
         end
+
+        def as_json(options = {})
+          result = {}
+
+          result["name".to_sym] = @name
+          result["identifierValue".to_sym] = @identifier_value
+          result["positiveIntValue".to_sym] = @positive_int_value
+          result["negativeIntValue".to_sym] = @negative_int_value
+          result["doubleValue".to_sym] = @double_value
+          result["stringValue".to_sym] = @string_value
+          result["aggregateValue".to_sym] = @aggregate_value
+          result
+        end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
       class FeatureSet
         def self.decode(buff)
@@ -31491,6 +32009,8 @@ def initialize(
           message_encoding: nil,
           json_format: nil
         )
+          @_oneof_json_names = {}
+
           if field_presence == nil
             @field_presence = 0
           else
@@ -32698,6 +33218,7 @@ def _encode(buff)
 
         def to_h
           result = {}
+
           result["field_presence".to_sym] = @field_presence
           result["enum_type".to_sym] = @enum_type
           result["repeated_field_encoding".to_sym] = @repeated_field_encoding
@@ -32706,6 +33227,23 @@ def to_h
           result["json_format".to_sym] = @json_format
           result
         end
+
+        def as_json(options = {})
+          result = {}
+
+          result["fieldPresence".to_sym] = @field_presence
+          result["enumType".to_sym] = @enum_type
+          result["repeatedFieldEncoding".to_sym] = @repeated_field_encoding
+          result["utf8Validation".to_sym] = @utf8_validation
+          result["messageEncoding".to_sym] = @message_encoding
+          result["jsonFormat".to_sym] = @json_format
+          result
+        end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
       class FeatureSetDefaults
         def self.decode(buff)
@@ -32760,6 +33298,8 @@ def initialize(
           )
             @_bitmask = 0
 
+            @_oneof_json_names = {}
+
             if edition == nil
               @edition = 0
             else
@@ -33552,11 +34092,26 @@ def _encode(buff)
 
           def to_h
             result = {}
+
             result["edition".to_sym] = @edition
             result["overridable_features".to_sym] = @overridable_features.to_h
             result["fixed_features".to_sym] = @fixed_features.to_h
             result
           end
+
+          def as_json(options = {})
+            result = {}
+
+            result["edition".to_sym] = @edition
+            result["overridableFeatures".to_sym] = @overridable_features.as_json
+            result["fixedFeatures".to_sym] = @fixed_features.as_json
+            result
+          end
+
+          def to_json(options = {})
+            require "json"
+            JSON.dump(as_json(options))
+          end
         end
         # required field readers
 
@@ -33587,6 +34142,8 @@ def maximum_edition=(v)
         end
 
         def initialize(defaults: [], minimum_edition: nil, maximum_edition: nil)
+          @_oneof_json_names = {}
+
           @defaults = defaults
 
           if minimum_edition == nil
@@ -34352,11 +34909,26 @@ def _encode(buff)
 
         def to_h
           result = {}
+
           result["defaults".to_sym] = @defaults
           result["minimum_edition".to_sym] = @minimum_edition
           result["maximum_edition".to_sym] = @maximum_edition
           result
         end
+
+        def as_json(options = {})
+          result = {}
+
+          result["defaults".to_sym] = @defaults
+          result["minimumEdition".to_sym] = @minimum_edition
+          result["maximumEdition".to_sym] = @maximum_edition
+          result
+        end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
       class SourceCodeInfo
         def self.decode(buff)
@@ -34436,6 +35008,8 @@ def initialize(
           )
             @_bitmask = 0
 
+            @_oneof_json_names = {}
+
             path.each do |v|
               unless -2_147_483_648 <= v && v <= 2_147_483_647
                 raise RangeError,
@@ -35673,6 +36247,7 @@ def _encode(buff)
 
           def to_h
             result = {}
+
             result["path".to_sym] = @path
             result["span".to_sym] = @span
             result["leading_comments".to_sym] = @leading_comments
@@ -35682,6 +36257,24 @@ def to_h
             ] = @leading_detached_comments
             result
           end
+
+          def as_json(options = {})
+            result = {}
+
+            result["path".to_sym] = @path
+            result["span".to_sym] = @span
+            result["leadingComments".to_sym] = @leading_comments
+            result["trailingComments".to_sym] = @trailing_comments
+            result[
+              "leadingDetachedComments".to_sym
+            ] = @leading_detached_comments
+            result
+          end
+
+          def to_json(options = {})
+            require "json"
+            JSON.dump(as_json(options))
+          end
         end
         # required field readers
 
@@ -35692,6 +36285,8 @@ def location=(v)
         end
 
         def initialize(location: [])
+          @_oneof_json_names = {}
+
           @location = location
         end
 
@@ -36137,9 +36732,22 @@ def _encode(buff)
 
         def to_h
           result = {}
+
           result["location".to_sym] = @location
           result
         end
+
+        def as_json(options = {})
+          result = {}
+
+          result["location".to_sym] = @location
+          result
+        end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
       class GeneratedCodeInfo
         def self.decode(buff)
@@ -36248,6 +36856,8 @@ def initialize(
           )
             @_bitmask = 0
 
+            @_oneof_json_names = {}
+
             path.each do |v|
               unless -2_147_483_648 <= v && v <= 2_147_483_647
                 raise RangeError,
@@ -37409,6 +38019,7 @@ def _encode(buff)
 
           def to_h
             result = {}
+
             result["path".to_sym] = @path
             result["source_file".to_sym] = @source_file
             result["begin".to_sym] = @begin
@@ -37416,6 +38027,22 @@ def to_h
             result["semantic".to_sym] = @semantic
             result
           end
+
+          def as_json(options = {})
+            result = {}
+
+            result["path".to_sym] = @path
+            result["sourceFile".to_sym] = @source_file
+            result["begin".to_sym] = @begin
+            result["end".to_sym] = @end
+            result["semantic".to_sym] = @semantic
+            result
+          end
+
+          def to_json(options = {})
+            require "json"
+            JSON.dump(as_json(options))
+          end
         end
         # required field readers
 
@@ -37426,6 +38053,8 @@ def annotation=(v)
         end
 
         def initialize(annotation: [])
+          @_oneof_json_names = {}
+
           @annotation = annotation
         end
 
@@ -37871,9 +38500,22 @@ def _encode(buff)
 
         def to_h
           result = {}
+
           result["annotation".to_sym] = @annotation
           result
         end
+
+        def as_json(options = {})
+          result = {}
+
+          result["annotation".to_sym] = @annotation
+          result
+        end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
     end
   end
diff --git a/lib/protoboeuf/google/protobuf/doublevalue.rb b/lib/protoboeuf/google/protobuf/doublevalue.rb
index 7bd516a..24a324a 100644
--- a/lib/protoboeuf/google/protobuf/doublevalue.rb
+++ b/lib/protoboeuf/google/protobuf/doublevalue.rb
@@ -22,6 +22,8 @@ def value=(v)
         end
 
         def initialize(value: 0.0)
+          @_oneof_json_names = {}
+
           @value = value
         end
 
@@ -343,9 +345,22 @@ def _encode(buff)
 
         def to_h
           result = {}
+
+          result["value".to_sym] = @value
+          result
+        end
+
+        def as_json(options = {})
+          result = {}
+
           result["value".to_sym] = @value
           result
         end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
     end
   end
diff --git a/lib/protoboeuf/google/protobuf/duration.rb b/lib/protoboeuf/google/protobuf/duration.rb
index c8848e9..a400728 100644
--- a/lib/protoboeuf/google/protobuf/duration.rb
+++ b/lib/protoboeuf/google/protobuf/duration.rb
@@ -39,6 +39,8 @@ def nanos=(v)
         end
 
         def initialize(seconds: 0, nanos: 0)
+          @_oneof_json_names = {}
+
           unless -9_223_372_036_854_775_808 <= seconds &&
                    seconds <= 9_223_372_036_854_775_807
             raise RangeError,
@@ -597,10 +599,24 @@ def _encode(buff)
 
         def to_h
           result = {}
+
           result["seconds".to_sym] = @seconds
           result["nanos".to_sym] = @nanos
           result
         end
+
+        def as_json(options = {})
+          result = {}
+
+          result["seconds".to_sym] = @seconds
+          result["nanos".to_sym] = @nanos
+          result
+        end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
     end
   end
diff --git a/lib/protoboeuf/google/protobuf/field_mask.rb b/lib/protoboeuf/google/protobuf/field_mask.rb
index a63d3af..6457984 100644
--- a/lib/protoboeuf/google/protobuf/field_mask.rb
+++ b/lib/protoboeuf/google/protobuf/field_mask.rb
@@ -22,6 +22,8 @@ def paths=(v)
         end
 
         def initialize(paths: [])
+          @_oneof_json_names = {}
+
           @paths = paths
         end
 
@@ -423,9 +425,22 @@ def _encode(buff)
 
         def to_h
           result = {}
+
+          result["paths".to_sym] = @paths
+          result
+        end
+
+        def as_json(options = {})
+          result = {}
+
           result["paths".to_sym] = @paths
           result
         end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
     end
   end
diff --git a/lib/protoboeuf/google/protobuf/floatvalue.rb b/lib/protoboeuf/google/protobuf/floatvalue.rb
index 395f0f3..11058a8 100644
--- a/lib/protoboeuf/google/protobuf/floatvalue.rb
+++ b/lib/protoboeuf/google/protobuf/floatvalue.rb
@@ -22,6 +22,8 @@ def value=(v)
         end
 
         def initialize(value: 0.0)
+          @_oneof_json_names = {}
+
           @value = value
         end
 
@@ -343,9 +345,22 @@ def _encode(buff)
 
         def to_h
           result = {}
+
+          result["value".to_sym] = @value
+          result
+        end
+
+        def as_json(options = {})
+          result = {}
+
           result["value".to_sym] = @value
           result
         end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
     end
   end
diff --git a/lib/protoboeuf/google/protobuf/int32value.rb b/lib/protoboeuf/google/protobuf/int32value.rb
index 99e1f76..6723aac 100644
--- a/lib/protoboeuf/google/protobuf/int32value.rb
+++ b/lib/protoboeuf/google/protobuf/int32value.rb
@@ -27,6 +27,8 @@ def value=(v)
         end
 
         def initialize(value: 0)
+          @_oneof_json_names = {}
+
           unless -2_147_483_648 <= value && value <= 2_147_483_647
             raise RangeError,
                   "Value (#{value}) for field value is out of bounds (-2147483648..2147483647)"
@@ -429,9 +431,22 @@ def _encode(buff)
 
         def to_h
           result = {}
+
+          result["value".to_sym] = @value
+          result
+        end
+
+        def as_json(options = {})
+          result = {}
+
           result["value".to_sym] = @value
           result
         end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
     end
   end
diff --git a/lib/protoboeuf/google/protobuf/int64value.rb b/lib/protoboeuf/google/protobuf/int64value.rb
index b0c8f8c..469a2af 100644
--- a/lib/protoboeuf/google/protobuf/int64value.rb
+++ b/lib/protoboeuf/google/protobuf/int64value.rb
@@ -28,6 +28,8 @@ def value=(v)
         end
 
         def initialize(value: 0)
+          @_oneof_json_names = {}
+
           unless -9_223_372_036_854_775_808 <= value &&
                    value <= 9_223_372_036_854_775_807
             raise RangeError,
@@ -431,9 +433,22 @@ def _encode(buff)
 
         def to_h
           result = {}
+
+          result["value".to_sym] = @value
+          result
+        end
+
+        def as_json(options = {})
+          result = {}
+
           result["value".to_sym] = @value
           result
         end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
     end
   end
diff --git a/lib/protoboeuf/google/protobuf/stringvalue.rb b/lib/protoboeuf/google/protobuf/stringvalue.rb
index 4ac9462..436ddc8 100644
--- a/lib/protoboeuf/google/protobuf/stringvalue.rb
+++ b/lib/protoboeuf/google/protobuf/stringvalue.rb
@@ -22,6 +22,8 @@ def value=(v)
         end
 
         def initialize(value: "")
+          @_oneof_json_names = {}
+
           @value = value
         end
 
@@ -408,9 +410,22 @@ def _encode(buff)
 
         def to_h
           result = {}
+
+          result["value".to_sym] = @value
+          result
+        end
+
+        def as_json(options = {})
+          result = {}
+
           result["value".to_sym] = @value
           result
         end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
     end
   end
diff --git a/lib/protoboeuf/google/protobuf/struct.rb b/lib/protoboeuf/google/protobuf/struct.rb
index 0228456..c3257d8 100644
--- a/lib/protoboeuf/google/protobuf/struct.rb
+++ b/lib/protoboeuf/google/protobuf/struct.rb
@@ -34,6 +34,8 @@ def fields=(v)
         end
 
         def initialize(fields: {})
+          @_oneof_json_names = {}
+
           @fields = fields
         end
 
@@ -628,9 +630,22 @@ def _encode(buff)
 
         def to_h
           result = {}
+
+          result["fields".to_sym] = @fields
+          result
+        end
+
+        def as_json(options = {})
+          result = {}
+
           result["fields".to_sym] = @fields
           result
         end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
       class Value
         def self.decode(buff)
@@ -698,6 +713,14 @@ def initialize(
           struct_value: nil,
           list_value: nil
         )
+          @_oneof_json_names = {
+            null_value: "nullValue",
+            number_value: "numberValue",
+            string_value: "stringValue",
+            bool_value: "boolValue",
+            struct_value: "structValue",
+            list_value: "listValue"
+          }
           @kind = nil # oneof field
           if null_value == nil
             @null_value = 0
@@ -1784,9 +1807,22 @@ def _encode(buff)
 
         def to_h
           result = {}
-          send("kind").tap { |f| result[f.to_sym] = send(f) if f }
+          send(field.name.dump).tap { |f| result[f.to_sym] = send(f) if f }
+
+          result
+        end
+
+        def as_json(options = {})
+          result = {}
+          send(field.name.dump).tap { |f| result[f.to_sym] = send(f) if f }
+
           result
         end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
       class ListValue
         def self.decode(buff)
@@ -1805,6 +1841,8 @@ def values=(v)
         end
 
         def initialize(values: [])
+          @_oneof_json_names = {}
+
           @values = values
         end
 
@@ -2250,9 +2288,22 @@ def _encode(buff)
 
         def to_h
           result = {}
+
+          result["values".to_sym] = @values
+          result
+        end
+
+        def as_json(options = {})
+          result = {}
+
           result["values".to_sym] = @values
           result
         end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
     end
   end
diff --git a/lib/protoboeuf/google/protobuf/timestamp.rb b/lib/protoboeuf/google/protobuf/timestamp.rb
index ff5cf7c..73a9786 100644
--- a/lib/protoboeuf/google/protobuf/timestamp.rb
+++ b/lib/protoboeuf/google/protobuf/timestamp.rb
@@ -39,6 +39,8 @@ def nanos=(v)
         end
 
         def initialize(seconds: 0, nanos: 0)
+          @_oneof_json_names = {}
+
           unless -9_223_372_036_854_775_808 <= seconds &&
                    seconds <= 9_223_372_036_854_775_807
             raise RangeError,
@@ -597,10 +599,24 @@ def _encode(buff)
 
         def to_h
           result = {}
+
           result["seconds".to_sym] = @seconds
           result["nanos".to_sym] = @nanos
           result
         end
+
+        def as_json(options = {})
+          result = {}
+
+          result["seconds".to_sym] = @seconds
+          result["nanos".to_sym] = @nanos
+          result
+        end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
     end
   end
diff --git a/lib/protoboeuf/google/protobuf/uint32value.rb b/lib/protoboeuf/google/protobuf/uint32value.rb
index bd54058..9963f3d 100644
--- a/lib/protoboeuf/google/protobuf/uint32value.rb
+++ b/lib/protoboeuf/google/protobuf/uint32value.rb
@@ -27,6 +27,8 @@ def value=(v)
         end
 
         def initialize(value: 0)
+          @_oneof_json_names = {}
+
           unless 0 <= value && value <= 18_446_744_073_709_551_615
             raise RangeError,
                   "Value (#{value}) for field value is out of bounds (0..18446744073709551615)"
@@ -412,9 +414,22 @@ def _encode(buff)
 
         def to_h
           result = {}
+
+          result["value".to_sym] = @value
+          result
+        end
+
+        def as_json(options = {})
+          result = {}
+
           result["value".to_sym] = @value
           result
         end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
     end
   end
diff --git a/lib/protoboeuf/google/protobuf/uint64value.rb b/lib/protoboeuf/google/protobuf/uint64value.rb
index e1764d8..f292a5e 100644
--- a/lib/protoboeuf/google/protobuf/uint64value.rb
+++ b/lib/protoboeuf/google/protobuf/uint64value.rb
@@ -27,6 +27,8 @@ def value=(v)
         end
 
         def initialize(value: 0)
+          @_oneof_json_names = {}
+
           unless 0 <= value && value <= 18_446_744_073_709_551_615
             raise RangeError,
                   "Value (#{value}) for field value is out of bounds (0..18446744073709551615)"
@@ -412,9 +414,22 @@ def _encode(buff)
 
         def to_h
           result = {}
+
+          result["value".to_sym] = @value
+          result
+        end
+
+        def as_json(options = {})
+          result = {}
+
           result["value".to_sym] = @value
           result
         end
+
+        def to_json(options = {})
+          require "json"
+          JSON.dump(as_json(options))
+        end
       end
     end
   end