diff --git a/openapiv3/annotations.pb.go b/openapiv3/annotations.pb.go
new file mode 100644
index 0000000..5c2b63e
--- /dev/null
+++ b/openapiv3/annotations.pb.go
@@ -0,0 +1,182 @@
+// Copyright 2022 Google LLC. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Code generated by protoc-gen-go. DO NOT EDIT.
+// versions:
+// 	protoc-gen-go v1.27.1
+// 	protoc        v3.19.3
+// source: openapiv3/annotations.proto
+
+package openapi_v3
+
+import (
+	protoreflect "google.golang.org/protobuf/reflect/protoreflect"
+	protoimpl "google.golang.org/protobuf/runtime/protoimpl"
+	descriptorpb "google.golang.org/protobuf/types/descriptorpb"
+	reflect "reflect"
+)
+
+const (
+	// Verify that this generated code is sufficiently up-to-date.
+	_ = protoimpl.EnforceVersion(20 - protoimpl.MinVersion)
+	// Verify that runtime/protoimpl is sufficiently up-to-date.
+	_ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20)
+)
+
+var file_openapiv3_annotations_proto_extTypes = []protoimpl.ExtensionInfo{
+	{
+		ExtendedType:  (*descriptorpb.FileOptions)(nil),
+		ExtensionType: (*Document)(nil),
+		Field:         1143,
+		Name:          "openapi.v3.document",
+		Tag:           "bytes,1143,opt,name=document",
+		Filename:      "openapiv3/annotations.proto",
+	},
+	{
+		ExtendedType:  (*descriptorpb.MethodOptions)(nil),
+		ExtensionType: (*Operation)(nil),
+		Field:         1143,
+		Name:          "openapi.v3.operation",
+		Tag:           "bytes,1143,opt,name=operation",
+		Filename:      "openapiv3/annotations.proto",
+	},
+	{
+		ExtendedType:  (*descriptorpb.MessageOptions)(nil),
+		ExtensionType: (*Schema)(nil),
+		Field:         1143,
+		Name:          "openapi.v3.schema",
+		Tag:           "bytes,1143,opt,name=schema",
+		Filename:      "openapiv3/annotations.proto",
+	},
+	{
+		ExtendedType:  (*descriptorpb.FieldOptions)(nil),
+		ExtensionType: (*Schema)(nil),
+		Field:         1143,
+		Name:          "openapi.v3.property",
+		Tag:           "bytes,1143,opt,name=property",
+		Filename:      "openapiv3/annotations.proto",
+	},
+}
+
+// Extension fields to descriptorpb.FileOptions.
+var (
+	// optional openapi.v3.Document document = 1143;
+	E_Document = &file_openapiv3_annotations_proto_extTypes[0]
+)
+
+// Extension fields to descriptorpb.MethodOptions.
+var (
+	// optional openapi.v3.Operation operation = 1143;
+	E_Operation = &file_openapiv3_annotations_proto_extTypes[1]
+)
+
+// Extension fields to descriptorpb.MessageOptions.
+var (
+	// optional openapi.v3.Schema schema = 1143;
+	E_Schema = &file_openapiv3_annotations_proto_extTypes[2]
+)
+
+// Extension fields to descriptorpb.FieldOptions.
+var (
+	// optional openapi.v3.Schema property = 1143;
+	E_Property = &file_openapiv3_annotations_proto_extTypes[3]
+)
+
+var File_openapiv3_annotations_proto protoreflect.FileDescriptor
+
+var file_openapiv3_annotations_proto_rawDesc = []byte{
+	0x0a, 0x1b, 0x6f, 0x70, 0x65, 0x6e, 0x61, 0x70, 0x69, 0x76, 0x33, 0x2f, 0x61, 0x6e, 0x6e, 0x6f,
+	0x74, 0x61, 0x74, 0x69, 0x6f, 0x6e, 0x73, 0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x12, 0x0a, 0x6f,
+	0x70, 0x65, 0x6e, 0x61, 0x70, 0x69, 0x2e, 0x76, 0x33, 0x1a, 0x20, 0x67, 0x6f, 0x6f, 0x67, 0x6c,
+	0x65, 0x2f, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x62, 0x75, 0x66, 0x2f, 0x64, 0x65, 0x73, 0x63, 0x72,
+	0x69, 0x70, 0x74, 0x6f, 0x72, 0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x1a, 0x19, 0x6f, 0x70, 0x65,
+	0x6e, 0x61, 0x70, 0x69, 0x76, 0x33, 0x2f, 0x4f, 0x70, 0x65, 0x6e, 0x41, 0x50, 0x49, 0x76, 0x33,
+	0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x3a, 0x4f, 0x0a, 0x08, 0x64, 0x6f, 0x63, 0x75, 0x6d, 0x65,
+	0x6e, 0x74, 0x12, 0x1c, 0x2e, 0x67, 0x6f, 0x6f, 0x67, 0x6c, 0x65, 0x2e, 0x70, 0x72, 0x6f, 0x74,
+	0x6f, 0x62, 0x75, 0x66, 0x2e, 0x46, 0x69, 0x6c, 0x65, 0x4f, 0x70, 0x74, 0x69, 0x6f, 0x6e, 0x73,
+	0x18, 0xf7, 0x08, 0x20, 0x01, 0x28, 0x0b, 0x32, 0x14, 0x2e, 0x6f, 0x70, 0x65, 0x6e, 0x61, 0x70,
+	0x69, 0x2e, 0x76, 0x33, 0x2e, 0x44, 0x6f, 0x63, 0x75, 0x6d, 0x65, 0x6e, 0x74, 0x52, 0x08, 0x64,
+	0x6f, 0x63, 0x75, 0x6d, 0x65, 0x6e, 0x74, 0x3a, 0x54, 0x0a, 0x09, 0x6f, 0x70, 0x65, 0x72, 0x61,
+	0x74, 0x69, 0x6f, 0x6e, 0x12, 0x1e, 0x2e, 0x67, 0x6f, 0x6f, 0x67, 0x6c, 0x65, 0x2e, 0x70, 0x72,
+	0x6f, 0x74, 0x6f, 0x62, 0x75, 0x66, 0x2e, 0x4d, 0x65, 0x74, 0x68, 0x6f, 0x64, 0x4f, 0x70, 0x74,
+	0x69, 0x6f, 0x6e, 0x73, 0x18, 0xf7, 0x08, 0x20, 0x01, 0x28, 0x0b, 0x32, 0x15, 0x2e, 0x6f, 0x70,
+	0x65, 0x6e, 0x61, 0x70, 0x69, 0x2e, 0x76, 0x33, 0x2e, 0x4f, 0x70, 0x65, 0x72, 0x61, 0x74, 0x69,
+	0x6f, 0x6e, 0x52, 0x09, 0x6f, 0x70, 0x65, 0x72, 0x61, 0x74, 0x69, 0x6f, 0x6e, 0x3a, 0x4c, 0x0a,
+	0x06, 0x73, 0x63, 0x68, 0x65, 0x6d, 0x61, 0x12, 0x1f, 0x2e, 0x67, 0x6f, 0x6f, 0x67, 0x6c, 0x65,
+	0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x62, 0x75, 0x66, 0x2e, 0x4d, 0x65, 0x73, 0x73, 0x61, 0x67,
+	0x65, 0x4f, 0x70, 0x74, 0x69, 0x6f, 0x6e, 0x73, 0x18, 0xf7, 0x08, 0x20, 0x01, 0x28, 0x0b, 0x32,
+	0x12, 0x2e, 0x6f, 0x70, 0x65, 0x6e, 0x61, 0x70, 0x69, 0x2e, 0x76, 0x33, 0x2e, 0x53, 0x63, 0x68,
+	0x65, 0x6d, 0x61, 0x52, 0x06, 0x73, 0x63, 0x68, 0x65, 0x6d, 0x61, 0x3a, 0x4e, 0x0a, 0x08, 0x70,
+	0x72, 0x6f, 0x70, 0x65, 0x72, 0x74, 0x79, 0x12, 0x1d, 0x2e, 0x67, 0x6f, 0x6f, 0x67, 0x6c, 0x65,
+	0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x62, 0x75, 0x66, 0x2e, 0x46, 0x69, 0x65, 0x6c, 0x64, 0x4f,
+	0x70, 0x74, 0x69, 0x6f, 0x6e, 0x73, 0x18, 0xf7, 0x08, 0x20, 0x01, 0x28, 0x0b, 0x32, 0x12, 0x2e,
+	0x6f, 0x70, 0x65, 0x6e, 0x61, 0x70, 0x69, 0x2e, 0x76, 0x33, 0x2e, 0x53, 0x63, 0x68, 0x65, 0x6d,
+	0x61, 0x52, 0x08, 0x70, 0x72, 0x6f, 0x70, 0x65, 0x72, 0x74, 0x79, 0x42, 0x42, 0x0a, 0x0e, 0x6f,
+	0x72, 0x67, 0x2e, 0x6f, 0x70, 0x65, 0x6e, 0x61, 0x70, 0x69, 0x5f, 0x76, 0x33, 0x42, 0x10, 0x41,
+	0x6e, 0x6e, 0x6f, 0x74, 0x61, 0x74, 0x69, 0x6f, 0x6e, 0x73, 0x50, 0x72, 0x6f, 0x74, 0x6f, 0x50,
+	0x01, 0x5a, 0x16, 0x2e, 0x2f, 0x6f, 0x70, 0x65, 0x6e, 0x61, 0x70, 0x69, 0x76, 0x33, 0x3b, 0x6f,
+	0x70, 0x65, 0x6e, 0x61, 0x70, 0x69, 0x5f, 0x76, 0x33, 0xa2, 0x02, 0x03, 0x4f, 0x41, 0x53, 0x62,
+	0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x33,
+}
+
+var file_openapiv3_annotations_proto_goTypes = []interface{}{
+	(*descriptorpb.FileOptions)(nil),    // 0: google.protobuf.FileOptions
+	(*descriptorpb.MethodOptions)(nil),  // 1: google.protobuf.MethodOptions
+	(*descriptorpb.MessageOptions)(nil), // 2: google.protobuf.MessageOptions
+	(*descriptorpb.FieldOptions)(nil),   // 3: google.protobuf.FieldOptions
+	(*Document)(nil),                    // 4: openapi.v3.Document
+	(*Operation)(nil),                   // 5: openapi.v3.Operation
+	(*Schema)(nil),                      // 6: openapi.v3.Schema
+}
+var file_openapiv3_annotations_proto_depIdxs = []int32{
+	0, // 0: openapi.v3.document:extendee -> google.protobuf.FileOptions
+	1, // 1: openapi.v3.operation:extendee -> google.protobuf.MethodOptions
+	2, // 2: openapi.v3.schema:extendee -> google.protobuf.MessageOptions
+	3, // 3: openapi.v3.property:extendee -> google.protobuf.FieldOptions
+	4, // 4: openapi.v3.document:type_name -> openapi.v3.Document
+	5, // 5: openapi.v3.operation:type_name -> openapi.v3.Operation
+	6, // 6: openapi.v3.schema:type_name -> openapi.v3.Schema
+	6, // 7: openapi.v3.property:type_name -> openapi.v3.Schema
+	8, // [8:8] is the sub-list for method output_type
+	8, // [8:8] is the sub-list for method input_type
+	4, // [4:8] is the sub-list for extension type_name
+	0, // [0:4] is the sub-list for extension extendee
+	0, // [0:0] is the sub-list for field type_name
+}
+
+func init() { file_openapiv3_annotations_proto_init() }
+func file_openapiv3_annotations_proto_init() {
+	if File_openapiv3_annotations_proto != nil {
+		return
+	}
+	file_openapiv3_OpenAPIv3_proto_init()
+	type x struct{}
+	out := protoimpl.TypeBuilder{
+		File: protoimpl.DescBuilder{
+			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
+			RawDescriptor: file_openapiv3_annotations_proto_rawDesc,
+			NumEnums:      0,
+			NumMessages:   0,
+			NumExtensions: 4,
+			NumServices:   0,
+		},
+		GoTypes:           file_openapiv3_annotations_proto_goTypes,
+		DependencyIndexes: file_openapiv3_annotations_proto_depIdxs,
+		ExtensionInfos:    file_openapiv3_annotations_proto_extTypes,
+	}.Build()
+	File_openapiv3_annotations_proto = out.File
+	file_openapiv3_annotations_proto_rawDesc = nil
+	file_openapiv3_annotations_proto_goTypes = nil
+	file_openapiv3_annotations_proto_depIdxs = nil
+}
diff --git a/openapiv3/annotations.proto b/openapiv3/annotations.proto
new file mode 100644
index 0000000..09ee0aa
--- /dev/null
+++ b/openapiv3/annotations.proto
@@ -0,0 +1,56 @@
+// Copyright 2022 Google LLC. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+syntax = "proto3";
+
+package openapi.v3;
+
+import "google/protobuf/descriptor.proto";
+import "openapiv3/OpenAPIv3.proto";
+
+// The Go package name.
+option go_package = "./openapiv3;openapi_v3";
+// This option lets the proto compiler generate Java code inside the package
+// name (see below) instead of inside an outer class. It creates a simpler
+// developer experience by reducing one-level of name nesting and be
+// consistent with most programming languages that don't support outer classes.
+option java_multiple_files = true;
+// The Java outer classname should be the filename in UpperCamelCase. This
+// class is only used to hold proto descriptor, so developers don't need to
+// work with it directly.
+option java_outer_classname = "AnnotationsProto";
+// The Java package name must be proto package name with proper prefix.
+option java_package = "org.openapi_v3";
+// A reasonable prefix for the Objective-C symbols generated from the package.
+// It should at a minimum be 3 characters long, all uppercase, and convention
+// is to use an abbreviation of the package name. Something short, but
+// hopefully unique enough to not conflict with things that may come along in
+// the future. 'GPB' is reserved for the protocol buffer implementation itself.
+option objc_class_prefix = "OAS";
+
+extend google.protobuf.FileOptions {
+  Document document = 1143;
+}
+
+extend google.protobuf.MethodOptions {
+  Operation operation = 1143;
+}
+
+extend google.protobuf.MessageOptions {
+  Schema schema = 1143;
+}
+
+extend google.protobuf.FieldOptions {
+  Schema property = 1143;
+}