From ffa01de78fc0bde0f2a1587862e8c9e15970f1f6 Mon Sep 17 00:00:00 2001
From: Vasiliy Tolstov <v.tolstov@unistack.org>
Date: Thu, 30 Jan 2025 23:26:45 +0300
Subject: [PATCH] broker: refactor (#396)

* remove subscribe from server
* remove publish from client
* broker package refactoring

Co-authored-by: vtolstov <vtolstov@users.noreply.github.com>
Reviewed-on: https://git.unistack.org/unistack-org/micro/pulls/396
Co-authored-by: Vasiliy Tolstov <v.tolstov@unistack.org>
Co-committed-by: Vasiliy Tolstov <v.tolstov@unistack.org>
---
 README.md                             |   2 +-
 broker/broker.go                      |  91 ++--
 broker/context.go                     |  10 -
 broker/context_test.go                |  11 -
 broker/memory/memory.go               | 413 ++++++++----------
 broker/memory/memory_test.go          |  94 ++--
 broker/noop.go                        | 104 +++--
 broker/noop_test.go                   |   4 +-
 broker/options.go                     |  96 +----
 {server => broker}/subscriber.go      |  25 +-
 client/client.go                      |  30 +-
 client/context.go                     |  10 -
 client/context_test.go                |  11 -
 client/noop.go                        | 142 +------
 client/noop_test.go                   |  35 --
 client/options.go                     |  98 -----
 codec/frame.proto                     |   2 +-
 codec/noop.go                         |   2 +-
 errors/errors.proto                   |   2 +-
 event.go                              |  27 --
 go.mod                                |  15 +-
 go.sum                                |  69 +--
 logger/slog/slog_test.go              |   7 +-
 metadata/context.go                   | 181 --------
 metadata/context_test.go              | 140 ------
 metadata/headers.go                   |  19 +
 metadata/metadata.go                  | 588 ++++++++++++++++++++------
 metadata/metadata_grpc.go             | 282 ------------
 metadata/metadata_test.go             | 207 +++++----
 micro_test.go                         |  24 +-
 network/network.go                    |  55 ---
 network/options.go                    | 135 ------
 network/transport/context.go          |  34 --
 network/transport/memory.go           | 258 -----------
 network/transport/memory_test.go      | 100 -----
 network/transport/options.go          | 175 --------
 network/transport/transport.go        |  63 ---
 network/tunnel/broker/broker.go       | 372 ----------------
 network/tunnel/options.go             | 192 ---------
 network/tunnel/transport/listener.go  |  30 --
 network/tunnel/transport/transport.go | 113 -----
 network/tunnel/tunnel.go              | 106 -----
 proxy/options.go                      |  98 -----
 proxy/proxy.go                        |  21 -
 register/memory/memory.go             |  29 +-
 server/noop.go                        | 369 +---------------
 server/noop_test.go                   | 124 ------
 server/registry.go                    |   4 -
 server/server.go                      |  58 +--
 server/wrapper.go                     |   8 -
 service.go                            |   5 -
 service_test.go                       |  36 --
 util/socket/pool.go                   |  65 ---
 util/socket/socket.go                 | 118 ------
 54 files changed, 1011 insertions(+), 4298 deletions(-)
 rename {server => broker}/subscriber.go (81%)
 delete mode 100644 client/noop_test.go
 delete mode 100644 event.go
 delete mode 100644 metadata/context.go
 delete mode 100644 metadata/context_test.go
 create mode 100644 metadata/headers.go
 delete mode 100644 metadata/metadata_grpc.go
 delete mode 100644 network/network.go
 delete mode 100644 network/options.go
 delete mode 100644 network/transport/context.go
 delete mode 100644 network/transport/memory.go
 delete mode 100644 network/transport/memory_test.go
 delete mode 100644 network/transport/options.go
 delete mode 100644 network/transport/transport.go
 delete mode 100644 network/tunnel/broker/broker.go
 delete mode 100644 network/tunnel/options.go
 delete mode 100644 network/tunnel/transport/listener.go
 delete mode 100644 network/tunnel/transport/transport.go
 delete mode 100644 network/tunnel/tunnel.go
 delete mode 100644 proxy/options.go
 delete mode 100644 proxy/proxy.go
 delete mode 100644 server/noop_test.go
 delete mode 100644 util/socket/pool.go
 delete mode 100644 util/socket/socket.go

diff --git a/README.md b/README.md
index a96be5a7..bf401306 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 # Micro
-![Coverage](https://img.shields.io/badge/Coverage-44.6%25-yellow)
+![Coverage](https://img.shields.io/badge/Coverage-43.9%25-yellow)
 [![License](https://img.shields.io/:license-apache-blue.svg)](https://opensource.org/licenses/Apache-2.0)
 [![Doc](https://img.shields.io/badge/go.dev-reference-007d9c?logo=go&logoColor=white&style=flat-square)](https://pkg.go.dev/go.unistack.org/micro/v3?tab=overview)
 [![Status](https://git.unistack.org/unistack-org/micro/actions/workflows/job_tests.yml/badge.svg?branch=v3)](https://git.unistack.org/unistack-org/micro/actions?query=workflow%3Abuild+branch%3Av3+event%3Apush)
diff --git a/broker/broker.go b/broker/broker.go
index 0dfea1fb..53b15d4e 100644
--- a/broker/broker.go
+++ b/broker/broker.go
@@ -18,6 +18,10 @@ var (
 	ErrNotConnected = errors.New("broker not connected")
 	// ErrDisconnected returns when broker disconnected
 	ErrDisconnected = errors.New("broker disconnected")
+	// ErrInvalidMessage returns when invalid Message passed
+	ErrInvalidMessage = errors.New("invalid message")
+	// ErrInvalidHandler returns when subscriber passed to Subscribe
+	ErrInvalidHandler = errors.New("invalid handler")
 	// DefaultGracefulTimeout
 	DefaultGracefulTimeout = 5 * time.Second
 )
@@ -36,14 +40,12 @@ type Broker interface {
 	Connect(ctx context.Context) error
 	// Disconnect disconnect from broker
 	Disconnect(ctx context.Context) error
+	// NewMessage create new broker message to publish.
+	NewMessage(ctx context.Context, hdr metadata.Metadata, body interface{}, opts ...PublishOption) (Message, error)
 	// Publish message to broker topic
-	Publish(ctx context.Context, topic string, msg *Message, opts ...PublishOption) error
+	Publish(ctx context.Context, topic string, messages ...Message) error
 	// Subscribe subscribes to topic message via handler
-	Subscribe(ctx context.Context, topic string, h Handler, opts ...SubscribeOption) (Subscriber, error)
-	// BatchPublish messages to broker with multiple topics
-	BatchPublish(ctx context.Context, msgs []*Message, opts ...PublishOption) error
-	// BatchSubscribe subscribes to topic messages via handler
-	BatchSubscribe(ctx context.Context, topic string, h BatchHandler, opts ...SubscribeOption) (Subscriber, error)
+	Subscribe(ctx context.Context, topic string, handler interface{}, opts ...SubscribeOption) (Subscriber, error)
 	// String type of broker
 	String() string
 	// Live returns broker liveness
@@ -55,72 +57,27 @@ type Broker interface {
 }
 
 type (
-	FuncPublish        func(ctx context.Context, topic string, msg *Message, opts ...PublishOption) error
-	HookPublish        func(next FuncPublish) FuncPublish
-	FuncBatchPublish   func(ctx context.Context, msgs []*Message, opts ...PublishOption) error
-	HookBatchPublish   func(next FuncBatchPublish) FuncBatchPublish
-	FuncSubscribe      func(ctx context.Context, topic string, h Handler, opts ...SubscribeOption) (Subscriber, error)
-	HookSubscribe      func(next FuncSubscribe) FuncSubscribe
-	FuncBatchSubscribe func(ctx context.Context, topic string, h BatchHandler, opts ...SubscribeOption) (Subscriber, error)
-	HookBatchSubscribe func(next FuncBatchSubscribe) FuncBatchSubscribe
+	FuncPublish   func(ctx context.Context, topic string, messages ...Message) error
+	HookPublish   func(next FuncPublish) FuncPublish
+	FuncSubscribe func(ctx context.Context, topic string, handler interface{}, opts ...SubscribeOption) (Subscriber, error)
+	HookSubscribe func(next FuncSubscribe) FuncSubscribe
 )
 
-// Handler is used to process messages via a subscription of a topic.
-type Handler func(Event) error
-
-// Events contains multiple events
-type Events []Event
-
-// Ack try to ack all events and return
-func (evs Events) Ack() error {
-	var err error
-	for _, ev := range evs {
-		if err = ev.Ack(); err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
-// SetError sets error on event
-func (evs Events) SetError(err error) {
-	for _, ev := range evs {
-		ev.SetError(err)
-	}
-}
-
-// BatchHandler is used to process messages in batches via a subscription of a topic.
-type BatchHandler func(Events) error
-
-// Event is given to a subscription handler for processing
-type Event interface {
-	// Context return context.Context for event
+// Message is given to a subscription handler for processing
+type Message interface {
+	// Context for the message.
 	Context() context.Context
-	// Topic returns event topic
+	// Topic returns message destination topic.
 	Topic() string
-	// Message returns broker message
-	Message() *Message
-	// Ack acknowledge message
+	// Header returns message headers.
+	Header() metadata.Metadata
+	// Body returns broker message []byte slice
+	Body() []byte
+	// Unmarshal try to decode message body to dst.
+	// This is helper method that uses codec.Unmarshal.
+	Unmarshal(dst interface{}, opts ...codec.Option) error
+	// Ack acknowledge message if supported.
 	Ack() error
-	// Error returns message error (like decoding errors or some other)
-	Error() error
-	// SetError set event processing error
-	SetError(err error)
-}
-
-// Message is used to transfer data
-type Message struct {
-	// Header contains message metadata
-	Header metadata.Metadata
-	// Body contains message body
-	Body codec.RawMessage
-}
-
-// NewMessage create broker message with topic filled
-func NewMessage(topic string) *Message {
-	m := &Message{Header: metadata.New(2)}
-	m.Header.Set(metadata.HeaderTopic, topic)
-	return m
 }
 
 // Subscriber is a convenience return type for the Subscribe method
diff --git a/broker/context.go b/broker/context.go
index 71d3e90a..6115511c 100644
--- a/broker/context.go
+++ b/broker/context.go
@@ -51,13 +51,3 @@ func SetOption(k, v interface{}) Option {
 		o.Context = context.WithValue(o.Context, k, v)
 	}
 }
-
-// SetPublishOption returns a function to setup a context with given value
-func SetPublishOption(k, v interface{}) PublishOption {
-	return func(o *PublishOptions) {
-		if o.Context == nil {
-			o.Context = context.Background()
-		}
-		o.Context = context.WithValue(o.Context, k, v)
-	}
-}
diff --git a/broker/context_test.go b/broker/context_test.go
index cd4feb5e..3860e93b 100644
--- a/broker/context_test.go
+++ b/broker/context_test.go
@@ -49,17 +49,6 @@ func TestSetSubscribeOption(t *testing.T) {
 	}
 }
 
-func TestSetPublishOption(t *testing.T) {
-	type key struct{}
-	o := SetPublishOption(key{}, "test")
-	opts := &PublishOptions{}
-	o(opts)
-
-	if v, ok := opts.Context.Value(key{}).(string); !ok || v == "" {
-		t.Fatal("SetPublishOption not works")
-	}
-}
-
 func TestSetOption(t *testing.T) {
 	type key struct{}
 	o := SetOption(key{}, "test")
diff --git a/broker/memory/memory.go b/broker/memory/memory.go
index 3030729d..c95c1b0c 100644
--- a/broker/memory/memory.go
+++ b/broker/memory/memory.go
@@ -2,9 +2,11 @@ package broker
 
 import (
 	"context"
+	"strings"
 	"sync"
 
 	"go.unistack.org/micro/v4/broker"
+	"go.unistack.org/micro/v4/codec"
 	"go.unistack.org/micro/v4/logger"
 	"go.unistack.org/micro/v4/metadata"
 	"go.unistack.org/micro/v4/options"
@@ -14,54 +16,90 @@ import (
 	"go.unistack.org/micro/v4/util/rand"
 )
 
-type memoryBroker struct {
-	funcPublish        broker.FuncPublish
-	funcBatchPublish   broker.FuncBatchPublish
-	funcSubscribe      broker.FuncSubscribe
-	funcBatchSubscribe broker.FuncBatchSubscribe
-	subscribers        map[string][]*memorySubscriber
-	addr               string
-	opts               broker.Options
+type Broker struct {
+	funcPublish   broker.FuncPublish
+	funcSubscribe broker.FuncSubscribe
+	subscribers   map[string][]*Subscriber
+	addr          string
+	opts          broker.Options
 	sync.RWMutex
 	connected bool
 }
 
-type memoryEvent struct {
-	err     error
-	message interface{}
+type memoryMessage struct {
+	c     codec.Codec
+	topic string
+	ctx   context.Context
+	body  []byte
+	hdr   metadata.Metadata
+	opts  broker.PublishOptions
+}
+
+func (m *memoryMessage) Ack() error {
+	return nil
+}
+
+func (m *memoryMessage) Body() []byte {
+	return m.body
+}
+
+func (m *memoryMessage) Header() metadata.Metadata {
+	return m.hdr
+}
+
+func (m *memoryMessage) Context() context.Context {
+	return m.ctx
+}
+
+func (m *memoryMessage) Topic() string {
+	return ""
+}
+
+func (m *memoryMessage) Unmarshal(dst interface{}, opts ...codec.Option) error {
+	return m.c.Unmarshal(m.body, dst)
+}
+
+type Subscriber struct {
+	ctx     context.Context
+	exit    chan bool
+	handler interface{}
+	id      string
 	topic   string
-	opts    broker.Options
+	opts    broker.SubscribeOptions
 }
 
-type memorySubscriber struct {
-	ctx          context.Context
-	exit         chan bool
-	handler      broker.Handler
-	batchhandler broker.BatchHandler
-	id           string
-	topic        string
-	opts         broker.SubscribeOptions
+func (b *Broker) newCodec(ct string) (codec.Codec, error) {
+	if idx := strings.IndexRune(ct, ';'); idx >= 0 {
+		ct = ct[:idx]
+	}
+	b.RLock()
+	c, ok := b.opts.Codecs[ct]
+	b.RUnlock()
+	if ok {
+		return c, nil
+	}
+	return nil, codec.ErrUnknownContentType
 }
 
-func (m *memoryBroker) Options() broker.Options {
-	return m.opts
+func (b *Broker) Options() broker.Options {
+	return b.opts
 }
 
-func (m *memoryBroker) Address() string {
-	return m.addr
+func (b *Broker) Address() string {
+	return b.addr
 }
 
-func (m *memoryBroker) Connect(ctx context.Context) error {
+func (b *Broker) Connect(ctx context.Context) error {
 	select {
 	case <-ctx.Done():
 		return ctx.Err()
 	default:
 	}
 
-	m.Lock()
-	defer m.Unlock()
+	b.Lock()
+	defer b.Unlock()
 
-	if m.connected {
+	if b.connected {
 		return nil
 	}
 
@@ -75,154 +113,126 @@ func (m *memoryBroker) Connect(ctx context.Context) error {
 	// set addr with port
 	addr = mnet.HostPort(addr, 10000+i)
 
-	m.addr = addr
-	m.connected = true
+	b.addr = addr
+	b.connected = true
 
 	return nil
 }
 
-func (m *memoryBroker) Disconnect(ctx context.Context) error {
+func (b *Broker) Disconnect(ctx context.Context) error {
 	select {
 	case <-ctx.Done():
 		return ctx.Err()
 	default:
 	}
 
-	m.Lock()
-	defer m.Unlock()
+	b.Lock()
+	defer b.Unlock()
 
-	if !m.connected {
+	if !b.connected {
 		return nil
 	}
 
-	m.connected = false
+	b.connected = false
 	return nil
 }
 
-func (m *memoryBroker) Init(opts ...broker.Option) error {
+func (b *Broker) Init(opts ...broker.Option) error {
 	for _, o := range opts {
-		o(&m.opts)
+		o(&b.opts)
 	}
 
-	m.funcPublish = m.fnPublish
-	m.funcBatchPublish = m.fnBatchPublish
-	m.funcSubscribe = m.fnSubscribe
-	m.funcBatchSubscribe = m.fnBatchSubscribe
+	b.funcPublish = b.fnPublish
+	b.funcSubscribe = b.fnSubscribe
 
-	m.opts.Hooks.EachPrev(func(hook options.Hook) {
+	b.opts.Hooks.EachPrev(func(hook options.Hook) {
 		switch h := hook.(type) {
 		case broker.HookPublish:
-			m.funcPublish = h(m.funcPublish)
-		case broker.HookBatchPublish:
-			m.funcBatchPublish = h(m.funcBatchPublish)
+			b.funcPublish = h(b.funcPublish)
 		case broker.HookSubscribe:
-			m.funcSubscribe = h(m.funcSubscribe)
-		case broker.HookBatchSubscribe:
-			m.funcBatchSubscribe = h(m.funcBatchSubscribe)
+			b.funcSubscribe = h(b.funcSubscribe)
 		}
 	})
 
 	return nil
 }
 
-func (m *memoryBroker) Publish(ctx context.Context, topic string, msg *broker.Message, opts ...broker.PublishOption) error {
-	return m.funcPublish(ctx, topic, msg, opts...)
+func (b *Broker) NewMessage(ctx context.Context, hdr metadata.Metadata, body interface{}, opts ...broker.PublishOption) (broker.Message, error) {
+	options := broker.NewPublishOptions(opts...)
+	m := &memoryMessage{ctx: ctx, hdr: hdr, opts: options}
+	c, err := b.newCodec(m.opts.ContentType)
+	if err == nil {
+		m.body, err = c.Marshal(body)
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	return m, nil
 }
 
-func (m *memoryBroker) fnPublish(ctx context.Context, topic string, msg *broker.Message, opts ...broker.PublishOption) error {
-	msg.Header.Set(metadata.HeaderTopic, topic)
-	return m.publish(ctx, []*broker.Message{msg}, opts...)
+func (b *Broker) Publish(ctx context.Context, topic string, messages ...broker.Message) error {
+	return b.funcPublish(ctx, topic, messages...)
 }
 
-func (m *memoryBroker) BatchPublish(ctx context.Context, msgs []*broker.Message, opts ...broker.PublishOption) error {
-	return m.funcBatchPublish(ctx, msgs, opts...)
+func (b *Broker) fnPublish(ctx context.Context, topic string, messages ...broker.Message) error {
+	return b.publish(ctx, topic, messages...)
 }
 
-func (m *memoryBroker) fnBatchPublish(ctx context.Context, msgs []*broker.Message, opts ...broker.PublishOption) error {
-	return m.publish(ctx, msgs, opts...)
-}
-
-func (m *memoryBroker) publish(ctx context.Context, msgs []*broker.Message, opts ...broker.PublishOption) error {
-	m.RLock()
-	if !m.connected {
-		m.RUnlock()
+func (b *Broker) publish(ctx context.Context, topic string, messages ...broker.Message) error {
+	b.RLock()
+	if !b.connected {
+		b.RUnlock()
 		return broker.ErrNotConnected
 	}
-	m.RUnlock()
-
-	var err error
+	b.RUnlock()
 
 	select {
 	case <-ctx.Done():
 		return ctx.Err()
 	default:
-		options := broker.NewPublishOptions(opts...)
+	}
 
-		msgTopicMap := make(map[string]broker.Events)
-		for _, v := range msgs {
-			p := &memoryEvent{opts: m.opts}
+	b.RLock()
+	subs, ok := b.subscribers[topic]
+	b.RUnlock()
+	if !ok {
+		return nil
+	}
 
-			if m.opts.Codec == nil || options.BodyOnly {
-				p.topic, _ = v.Header.Get(metadata.HeaderTopic)
-				p.message = v.Body
-			} else {
-				p.topic, _ = v.Header.Get(metadata.HeaderTopic)
-				p.message, err = m.opts.Codec.Marshal(v)
-				if err != nil {
-					return err
-				}
+	var err error
+
+	for _, sub := range subs {
+		switch s := sub.handler.(type) {
+		default:
+			if b.opts.Logger.V(logger.ErrorLevel) {
+				b.opts.Logger.Error(ctx, "broker  handler error", broker.ErrInvalidHandler)
 			}
-			msgTopicMap[p.topic] = append(msgTopicMap[p.topic], p)
-		}
-
-		beh := m.opts.BatchErrorHandler
-		eh := m.opts.ErrorHandler
-
-		for t, ms := range msgTopicMap {
-			m.RLock()
-			subs, ok := m.subscribers[t]
-			m.RUnlock()
-			if !ok {
-				continue
-			}
-
-			for _, sub := range subs {
-				if sub.opts.BatchErrorHandler != nil {
-					beh = sub.opts.BatchErrorHandler
-				}
-				if sub.opts.ErrorHandler != nil {
-					eh = sub.opts.ErrorHandler
-				}
-
-				switch {
-				// batch processing
-				case sub.batchhandler != nil:
-					if err = sub.batchhandler(ms); err != nil {
-						ms.SetError(err)
-						if beh != nil {
-							_ = beh(ms)
-						} else if m.opts.Logger.V(logger.ErrorLevel) {
-							m.opts.Logger.Error(m.opts.Context, err.Error())
-						}
-					} else if sub.opts.AutoAck {
-						if err = ms.Ack(); err != nil {
-							m.opts.Logger.Error(m.opts.Context, "broker ack error", err)
-						}
+		case func(broker.Message) error:
+			for _, message := range messages {
+				msg, ok := message.(*memoryMessage)
+				if !ok {
+					if b.opts.Logger.V(logger.ErrorLevel) {
+						b.opts.Logger.Error(ctx, "broker handler error", broker.ErrInvalidMessage)
 					}
-					// single processing
-				case sub.handler != nil:
-					for _, p := range ms {
-						if err = sub.handler(p); err != nil {
-							p.SetError(err)
-							if eh != nil {
-								_ = eh(p)
-							} else if m.opts.Logger.V(logger.ErrorLevel) {
-								m.opts.Logger.Error(m.opts.Context, "broker handler error", err)
-							}
-						} else if sub.opts.AutoAck {
-							if err = p.Ack(); err != nil {
-								m.opts.Logger.Error(m.opts.Context, "broker ack error", err)
-							}
+				}
+				msg.topic = topic
+				if err = s(msg); err == nil && sub.opts.AutoAck {
+					err = msg.Ack()
+				}
+				if err != nil {
+					if b.opts.Logger.V(logger.ErrorLevel) {
+						b.opts.Logger.Error(ctx, "broker handler error", err)
+					}
+				}
+			}
+		case func([]broker.Message) error:
+			if err = s(messages); err == nil && sub.opts.AutoAck {
+				for _, message := range messages {
+					err = message.Ack()
+					if err != nil {
+						if b.opts.Logger.V(logger.ErrorLevel) {
+							b.opts.Logger.Error(ctx, "broker handler error", err)
 						}
 					}
 				}
@@ -233,17 +243,21 @@ func (m *memoryBroker) publish(ctx context.Context, msgs []*broker.Message, opts
 	return nil
 }
 
-func (m *memoryBroker) BatchSubscribe(ctx context.Context, topic string, handler broker.BatchHandler, opts ...broker.SubscribeOption) (broker.Subscriber, error) {
-	return m.funcBatchSubscribe(ctx, topic, handler, opts...)
+func (b *Broker) Subscribe(ctx context.Context, topic string, handler interface{}, opts ...broker.SubscribeOption) (broker.Subscriber, error) {
+	return b.funcSubscribe(ctx, topic, handler, opts...)
 }
 
-func (m *memoryBroker) fnBatchSubscribe(ctx context.Context, topic string, handler broker.BatchHandler, opts ...broker.SubscribeOption) (broker.Subscriber, error) {
-	m.RLock()
-	if !m.connected {
-		m.RUnlock()
+func (b *Broker) fnSubscribe(ctx context.Context, topic string, handler interface{}, opts ...broker.SubscribeOption) (broker.Subscriber, error) {
+	if err := broker.IsValidHandler(handler); err != nil {
+		return nil, err
+	}
+
+	b.RLock()
+	if !b.connected {
+		b.RUnlock()
 		return nil, broker.ErrNotConnected
 	}
-	m.RUnlock()
+	b.RUnlock()
 
 	sid, err := id.New()
 	if err != nil {
@@ -252,56 +266,7 @@ func (m *memoryBroker) fnBatchSubscribe(ctx context.Context, topic string, handl
 
 	options := broker.NewSubscribeOptions(opts...)
 
-	sub := &memorySubscriber{
-		exit:         make(chan bool, 1),
-		id:           sid,
-		topic:        topic,
-		batchhandler: handler,
-		opts:         options,
-		ctx:          ctx,
-	}
-
-	m.Lock()
-	m.subscribers[topic] = append(m.subscribers[topic], sub)
-	m.Unlock()
-
-	go func() {
-		<-sub.exit
-		m.Lock()
-		newSubscribers := make([]*memorySubscriber, 0, len(m.subscribers)-1)
-		for _, sb := range m.subscribers[topic] {
-			if sb.id == sub.id {
-				continue
-			}
-			newSubscribers = append(newSubscribers, sb)
-		}
-		m.subscribers[topic] = newSubscribers
-		m.Unlock()
-	}()
-
-	return sub, nil
-}
-
-func (m *memoryBroker) Subscribe(ctx context.Context, topic string, handler broker.Handler, opts ...broker.SubscribeOption) (broker.Subscriber, error) {
-	return m.funcSubscribe(ctx, topic, handler, opts...)
-}
-
-func (m *memoryBroker) fnSubscribe(ctx context.Context, topic string, handler broker.Handler, opts ...broker.SubscribeOption) (broker.Subscriber, error) {
-	m.RLock()
-	if !m.connected {
-		m.RUnlock()
-		return nil, broker.ErrNotConnected
-	}
-	m.RUnlock()
-
-	sid, err := id.New()
-	if err != nil {
-		return nil, err
-	}
-
-	options := broker.NewSubscribeOptions(opts...)
-
-	sub := &memorySubscriber{
+	sub := &Subscriber{
 		exit:    make(chan bool, 1),
 		id:      sid,
 		topic:   topic,
@@ -310,102 +275,64 @@ func (m *memoryBroker) fnSubscribe(ctx context.Context, topic string, handler br
 		ctx:     ctx,
 	}
 
-	m.Lock()
-	m.subscribers[topic] = append(m.subscribers[topic], sub)
-	m.Unlock()
+	b.Lock()
+	b.subscribers[topic] = append(b.subscribers[topic], sub)
+	b.Unlock()
 
 	go func() {
 		<-sub.exit
-		m.Lock()
-		newSubscribers := make([]*memorySubscriber, 0, len(m.subscribers)-1)
-		for _, sb := range m.subscribers[topic] {
+		b.Lock()
+		newSubscribers := make([]*Subscriber, 0, len(b.subscribers)-1)
+		for _, sb := range b.subscribers[topic] {
 			if sb.id == sub.id {
 				continue
 			}
 			newSubscribers = append(newSubscribers, sb)
 		}
-		m.subscribers[topic] = newSubscribers
-		m.Unlock()
+		b.subscribers[topic] = newSubscribers
+		b.Unlock()
 	}()
 
 	return sub, nil
 }
 
-func (m *memoryBroker) String() string {
+func (b *Broker) String() string {
 	return "memory"
 }
 
-func (m *memoryBroker) Name() string {
-	return m.opts.Name
+func (b *Broker) Name() string {
+	return b.opts.Name
 }
 
-func (m *memoryBroker) Live() bool {
+func (b *Broker) Live() bool {
 	return true
 }
 
-func (m *memoryBroker) Ready() bool {
+func (b *Broker) Ready() bool {
 	return true
 }
 
-func (m *memoryBroker) Health() bool {
+func (b *Broker) Health() bool {
 	return true
 }
 
-func (m *memoryEvent) Topic() string {
-	return m.topic
-}
-
-func (m *memoryEvent) Message() *broker.Message {
-	switch v := m.message.(type) {
-	case *broker.Message:
-		return v
-	case []byte:
-		msg := &broker.Message{}
-		if err := m.opts.Codec.Unmarshal(v, msg); err != nil {
-			if m.opts.Logger.V(logger.ErrorLevel) {
-				m.opts.Logger.Error(m.opts.Context, "[memory]: failed to unmarshal: %v", err)
-			}
-			return nil
-		}
-		return msg
-	}
-
-	return nil
-}
-
-func (m *memoryEvent) Ack() error {
-	return nil
-}
-
-func (m *memoryEvent) Error() error {
-	return m.err
-}
-
-func (m *memoryEvent) SetError(err error) {
-	m.err = err
-}
-
-func (m *memoryEvent) Context() context.Context {
-	return m.opts.Context
-}
-
-func (m *memorySubscriber) Options() broker.SubscribeOptions {
+func (m *Subscriber) Options() broker.SubscribeOptions {
 	return m.opts
 }
 
-func (m *memorySubscriber) Topic() string {
+func (m *Subscriber) Topic() string {
 	return m.topic
 }
 
-func (m *memorySubscriber) Unsubscribe(ctx context.Context) error {
+func (m *Subscriber) Unsubscribe(ctx context.Context) error {
 	m.exit <- true
 	return nil
 }
 
 // NewBroker return new memory broker
 func NewBroker(opts ...broker.Option) broker.Broker {
-	return &memoryBroker{
+	return &Broker{
 		opts:        broker.NewOptions(opts...),
-		subscribers: make(map[string][]*memorySubscriber),
+		subscribers: make(map[string][]*Subscriber),
 	}
 }
diff --git a/broker/memory/memory_test.go b/broker/memory/memory_test.go
index 737d1b98..2d2fd4de 100644
--- a/broker/memory/memory_test.go
+++ b/broker/memory/memory_test.go
@@ -5,62 +5,23 @@ import (
 	"fmt"
 	"testing"
 
+	"go.uber.org/atomic"
 	"go.unistack.org/micro/v4/broker"
+	"go.unistack.org/micro/v4/codec"
 	"go.unistack.org/micro/v4/metadata"
 )
 
-func TestMemoryBatchBroker(t *testing.T) {
-	b := NewBroker()
-	ctx := context.Background()
+type hldr struct {
+	c atomic.Int64
+}
 
-	if err := b.Init(); err != nil {
-		t.Fatalf("Unexpected init error %v", err)
-	}
-
-	if err := b.Connect(ctx); err != nil {
-		t.Fatalf("Unexpected connect error %v", err)
-	}
-
-	topic := "test"
-	count := 10
-
-	fn := func(evts broker.Events) error {
-		return evts.Ack()
-	}
-
-	sub, err := b.BatchSubscribe(ctx, topic, fn)
-	if err != nil {
-		t.Fatalf("Unexpected error subscribing %v", err)
-	}
-
-	msgs := make([]*broker.Message, 0, count)
-	for i := 0; i < count; i++ {
-		message := &broker.Message{
-			Header: map[string]string{
-				metadata.HeaderTopic: topic,
-				"foo":                "bar",
-				"id":                 fmt.Sprintf("%d", i),
-			},
-			Body: []byte(`"hello world"`),
-		}
-		msgs = append(msgs, message)
-	}
-
-	if err := b.BatchPublish(ctx, msgs); err != nil {
-		t.Fatalf("Unexpected error publishing %v", err)
-	}
-
-	if err := sub.Unsubscribe(ctx); err != nil {
-		t.Fatalf("Unexpected error unsubscribing from %s: %v", topic, err)
-	}
-
-	if err := b.Disconnect(ctx); err != nil {
-		t.Fatalf("Unexpected connect error %v", err)
-	}
+func (h *hldr) Handler(m broker.Message) error {
+	h.c.Add(1)
+	return nil
 }
 
 func TestMemoryBroker(t *testing.T) {
-	b := NewBroker()
+	b := NewBroker(broker.Codec("application/octet-stream", codec.NewCodec()))
 	ctx := context.Background()
 
 	if err := b.Init(); err != nil {
@@ -72,38 +33,33 @@ func TestMemoryBroker(t *testing.T) {
 	}
 
 	topic := "test"
-	count := 10
+	count := int64(10)
 
-	fn := func(_ broker.Event) error {
-		return nil
-	}
+	h := &hldr{}
 
-	sub, err := b.Subscribe(ctx, topic, fn)
+	sub, err := b.Subscribe(ctx, topic, h.Handler)
 	if err != nil {
 		t.Fatalf("Unexpected error subscribing %v", err)
 	}
 
-	msgs := make([]*broker.Message, 0, count)
-	for i := 0; i < count; i++ {
-		message := &broker.Message{
-			Header: map[string]string{
-				metadata.HeaderTopic: topic,
-				"foo":                "bar",
-				"id":                 fmt.Sprintf("%d", i),
-			},
-			Body: []byte(`"hello world"`),
+	for i := int64(0); i < count; i++ {
+		message, err := b.NewMessage(ctx,
+			metadata.Pairs(
+				"foo", "bar",
+				"id", fmt.Sprintf("%d", i),
+			),
+			[]byte(`"hello world"`),
+			broker.PublishContentType("application/octet-stream"),
+		)
+		if err != nil {
+			t.Fatal(err)
 		}
-		msgs = append(msgs, message)
 
 		if err := b.Publish(ctx, topic, message); err != nil {
 			t.Fatalf("Unexpected error publishing %d err: %v", i, err)
 		}
 	}
 
-	if err := b.BatchPublish(ctx, msgs); err != nil {
-		t.Fatalf("Unexpected error publishing %v", err)
-	}
-
 	if err := sub.Unsubscribe(ctx); err != nil {
 		t.Fatalf("Unexpected error unsubscribing from %s: %v", topic, err)
 	}
@@ -111,4 +67,8 @@ func TestMemoryBroker(t *testing.T) {
 	if err := b.Disconnect(ctx); err != nil {
 		t.Fatalf("Unexpected connect error %v", err)
 	}
+
+	if h.c.Load() != count {
+		t.Fatal("invalid messages count received")
+	}
 }
diff --git a/broker/noop.go b/broker/noop.go
index 625ababc..4d160f3d 100644
--- a/broker/noop.go
+++ b/broker/noop.go
@@ -3,24 +3,37 @@ package broker
 import (
 	"context"
 	"strings"
+	"sync"
 
+	"go.unistack.org/micro/v4/codec"
+	"go.unistack.org/micro/v4/metadata"
 	"go.unistack.org/micro/v4/options"
 )
 
 type NoopBroker struct {
-	funcPublish        FuncPublish
-	funcBatchPublish   FuncBatchPublish
-	funcSubscribe      FuncSubscribe
-	funcBatchSubscribe FuncBatchSubscribe
-	opts               Options
+	funcPublish   FuncPublish
+	funcSubscribe FuncSubscribe
+	opts          Options
+	sync.RWMutex
+}
+
+func (b *NoopBroker) newCodec(ct string) (codec.Codec, error) {
+	if idx := strings.IndexRune(ct, ';'); idx >= 0 {
+		ct = ct[:idx]
+	}
+	b.RLock()
+	c, ok := b.opts.Codecs[ct]
+	b.RUnlock()
+	if ok {
+		return c, nil
+	}
+	return nil, codec.ErrUnknownContentType
 }
 
 func NewBroker(opts ...Option) *NoopBroker {
 	b := &NoopBroker{opts: NewOptions(opts...)}
 	b.funcPublish = b.fnPublish
-	b.funcBatchPublish = b.fnBatchPublish
 	b.funcSubscribe = b.fnSubscribe
-	b.funcBatchSubscribe = b.fnBatchSubscribe
 
 	return b
 }
@@ -55,20 +68,14 @@ func (b *NoopBroker) Init(opts ...Option) error {
 	}
 
 	b.funcPublish = b.fnPublish
-	b.funcBatchPublish = b.fnBatchPublish
 	b.funcSubscribe = b.fnSubscribe
-	b.funcBatchSubscribe = b.fnBatchSubscribe
 
 	b.opts.Hooks.EachPrev(func(hook options.Hook) {
 		switch h := hook.(type) {
 		case HookPublish:
 			b.funcPublish = h(b.funcPublish)
-		case HookBatchPublish:
-			b.funcBatchPublish = h(b.funcBatchPublish)
 		case HookSubscribe:
 			b.funcSubscribe = h(b.funcSubscribe)
-		case HookBatchSubscribe:
-			b.funcBatchSubscribe = h(b.funcBatchSubscribe)
 		}
 	})
 
@@ -87,43 +94,72 @@ func (b *NoopBroker) Address() string {
 	return strings.Join(b.opts.Addrs, ",")
 }
 
-func (b *NoopBroker) fnBatchPublish(_ context.Context, _ []*Message, _ ...PublishOption) error {
+type noopMessage struct {
+	c    codec.Codec
+	ctx  context.Context
+	body []byte
+	hdr  metadata.Metadata
+	opts PublishOptions
+}
+
+func (m *noopMessage) Ack() error {
 	return nil
 }
 
-func (b *NoopBroker) BatchPublish(ctx context.Context, msgs []*Message, opts ...PublishOption) error {
-	return b.funcBatchPublish(ctx, msgs, opts...)
+func (m *noopMessage) Body() []byte {
+	return m.body
 }
 
-func (b *NoopBroker) fnPublish(_ context.Context, _ string, _ *Message, _ ...PublishOption) error {
+func (m *noopMessage) Header() metadata.Metadata {
+	return m.hdr
+}
+
+func (m *noopMessage) Context() context.Context {
+	return m.ctx
+}
+
+func (m *noopMessage) Topic() string {
+	return ""
+}
+
+func (m *noopMessage) Unmarshal(dst interface{}, opts ...codec.Option) error {
+	return m.c.Unmarshal(m.body, dst)
+}
+
+func (b *NoopBroker) NewMessage(ctx context.Context, hdr metadata.Metadata, body interface{}, opts ...PublishOption) (Message, error) {
+	options := NewPublishOptions(opts...)
+	m := &noopMessage{ctx: ctx, hdr: hdr, opts: options}
+	c, err := b.newCodec(m.opts.ContentType)
+	if err == nil {
+		m.body, err = c.Marshal(body)
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	return m, nil
+}
+
+func (b *NoopBroker) fnPublish(_ context.Context, _ string, _ ...Message) error {
 	return nil
 }
 
-func (b *NoopBroker) Publish(ctx context.Context, topic string, msg *Message, opts ...PublishOption) error {
-	return b.funcPublish(ctx, topic, msg, opts...)
+func (b *NoopBroker) Publish(ctx context.Context, topic string, msg ...Message) error {
+	return b.funcPublish(ctx, topic, msg...)
 }
 
 type NoopSubscriber struct {
-	ctx          context.Context
-	topic        string
-	handler      Handler
-	batchHandler BatchHandler
-	opts         SubscribeOptions
+	ctx     context.Context
+	topic   string
+	handler interface{}
+	opts    SubscribeOptions
 }
 
-func (b *NoopBroker) fnBatchSubscribe(ctx context.Context, topic string, handler BatchHandler, opts ...SubscribeOption) (Subscriber, error) {
-	return &NoopSubscriber{ctx: ctx, topic: topic, opts: NewSubscribeOptions(opts...), batchHandler: handler}, nil
-}
-
-func (b *NoopBroker) BatchSubscribe(ctx context.Context, topic string, handler BatchHandler, opts ...SubscribeOption) (Subscriber, error) {
-	return b.funcBatchSubscribe(ctx, topic, handler, opts...)
-}
-
-func (b *NoopBroker) fnSubscribe(ctx context.Context, topic string, handler Handler, opts ...SubscribeOption) (Subscriber, error) {
+func (b *NoopBroker) fnSubscribe(ctx context.Context, topic string, handler interface{}, opts ...SubscribeOption) (Subscriber, error) {
 	return &NoopSubscriber{ctx: ctx, topic: topic, opts: NewSubscribeOptions(opts...), handler: handler}, nil
 }
 
-func (b *NoopBroker) Subscribe(ctx context.Context, topic string, handler Handler, opts ...SubscribeOption) (Subscriber, error) {
+func (b *NoopBroker) Subscribe(ctx context.Context, topic string, handler interface{}, opts ...SubscribeOption) (Subscriber, error) {
 	return b.funcSubscribe(ctx, topic, handler, opts...)
 }
 
diff --git a/broker/noop_test.go b/broker/noop_test.go
index 824b4b00..8350b118 100644
--- a/broker/noop_test.go
+++ b/broker/noop_test.go
@@ -10,9 +10,9 @@ type testHook struct {
 }
 
 func (t *testHook) Publish1(fn FuncPublish) FuncPublish {
-	return func(ctx context.Context, topic string, msg *Message, opts ...PublishOption) error {
+	return func(ctx context.Context, topic string, messages ...Message) error {
 		t.f = true
-		return fn(ctx, topic, msg, opts...)
+		return fn(ctx, topic, messages...)
 	}
 }
 
diff --git a/broker/options.go b/broker/options.go
index 717fb10a..a9900921 100644
--- a/broker/options.go
+++ b/broker/options.go
@@ -23,8 +23,8 @@ type Options struct {
 	Tracer tracer.Tracer
 	// Register can be used for clustering
 	Register register.Register
-	// Codec holds the codec for marshal/unmarshal
-	Codec codec.Codec
+	// Codecs holds the codecs for marshal/unmarshal based on content-type
+	Codecs map[string]codec.Codec
 	// Logger used for logging
 	Logger logger.Logger
 	// Meter used for metrics
@@ -37,11 +37,6 @@ type Options struct {
 	// TLSConfig holds tls.TLSConfig options
 	TLSConfig *tls.Config
 
-	// ErrorHandler used when broker can't unmarshal incoming message
-	ErrorHandler Handler
-	// BatchErrorHandler used when broker can't unmashal incoming messages
-	BatchErrorHandler BatchHandler
-
 	// Addrs holds the broker address
 	Addrs []string
 	// Hooks can be run before broker Publish/BatchPublish and
@@ -59,10 +54,11 @@ func NewOptions(opts ...Option) Options {
 		Logger:          logger.DefaultLogger,
 		Context:         context.Background(),
 		Meter:           meter.DefaultMeter,
-		Codec:           codec.DefaultCodec,
+		Codecs:          make(map[string]codec.Codec),
 		Tracer:          tracer.DefaultTracer,
 		GracefulTimeout: DefaultGracefulTimeout,
 	}
+
 	for _, o := range opts {
 		o(&options)
 	}
@@ -78,17 +74,16 @@ func Context(ctx context.Context) Option {
 
 // PublishOptions struct
 type PublishOptions struct {
-	// Context holds external options
-	Context context.Context
-	// BodyOnly flag says the message contains raw body bytes
+	// ContentType for message body
+	ContentType string
+	// BodyOnly flag says the message contains raw body bytes and don't need
+	// codec Marshal method
 	BodyOnly bool
 }
 
 // NewPublishOptions creates PublishOptions struct
 func NewPublishOptions(opts ...PublishOption) PublishOptions {
-	options := PublishOptions{
-		Context: context.Background(),
-	}
+	options := PublishOptions{}
 	for _, o := range opts {
 		o(&options)
 	}
@@ -99,10 +94,6 @@ func NewPublishOptions(opts ...PublishOption) PublishOptions {
 type SubscribeOptions struct {
 	// Context holds external options
 	Context context.Context
-	// ErrorHandler used when broker can't unmarshal incoming message
-	ErrorHandler Handler
-	// BatchErrorHandler used when broker can't unmashal incoming messages
-	BatchErrorHandler BatchHandler
 	// Group holds consumer group
 	Group string
 	// AutoAck flag specifies auto ack of incoming message when no error happens
@@ -121,6 +112,13 @@ type Option func(*Options)
 // PublishOption func
 type PublishOption func(*PublishOptions)
 
+// PublishContentType sets message content-type that used to Marshal
+func PublishContentType(ct string) PublishOption {
+	return func(o *PublishOptions) {
+		o.ContentType = ct
+	}
+}
+
 // PublishBodyOnly publish only body of the message
 func PublishBodyOnly(b bool) PublishOption {
 	return func(o *PublishOptions) {
@@ -128,13 +126,6 @@ func PublishBodyOnly(b bool) PublishOption {
 	}
 }
 
-// PublishContext sets the context
-func PublishContext(ctx context.Context) PublishOption {
-	return func(o *PublishOptions) {
-		o.Context = ctx
-	}
-}
-
 // Addrs sets the host addresses to be used by the broker
 func Addrs(addrs ...string) Option {
 	return func(o *Options) {
@@ -142,51 +133,10 @@ func Addrs(addrs ...string) Option {
 	}
 }
 
-// Codec sets the codec used for encoding/decoding used where
-// a broker does not support headers
-func Codec(c codec.Codec) Option {
+// Codec sets the codec used for encoding/decoding messages
+func Codec(ct string, c codec.Codec) Option {
 	return func(o *Options) {
-		o.Codec = c
-	}
-}
-
-// ErrorHandler will catch all broker errors that cant be handled
-// in normal way, for example Codec errors
-func ErrorHandler(h Handler) Option {
-	return func(o *Options) {
-		o.ErrorHandler = h
-	}
-}
-
-// BatchErrorHandler will catch all broker errors that cant be handled
-// in normal way, for example Codec errors
-func BatchErrorHandler(h BatchHandler) Option {
-	return func(o *Options) {
-		o.BatchErrorHandler = h
-	}
-}
-
-// SubscribeErrorHandler will catch all broker errors that cant be handled
-// in normal way, for example Codec errors
-func SubscribeErrorHandler(h Handler) SubscribeOption {
-	return func(o *SubscribeOptions) {
-		o.ErrorHandler = h
-	}
-}
-
-// SubscribeBatchErrorHandler will catch all broker errors that cant be handled
-// in normal way, for example Codec errors
-func SubscribeBatchErrorHandler(h BatchHandler) SubscribeOption {
-	return func(o *SubscribeOptions) {
-		o.BatchErrorHandler = h
-	}
-}
-
-// Queue sets the subscribers queue
-// Deprecated
-func Queue(name string) SubscribeOption {
-	return func(o *SubscribeOptions) {
-		o.Group = name
+		o.Codecs[ct] = c
 	}
 }
 
@@ -253,14 +203,6 @@ func SubscribeContext(ctx context.Context) SubscribeOption {
 	}
 }
 
-// DisableAutoAck disables auto ack
-// Deprecated
-func DisableAutoAck() SubscribeOption {
-	return func(o *SubscribeOptions) {
-		o.AutoAck = false
-	}
-}
-
 // SubscribeAutoAck contol auto acking of messages
 // after they have been handled.
 func SubscribeAutoAck(b bool) SubscribeOption {
diff --git a/server/subscriber.go b/broker/subscriber.go
similarity index 81%
rename from server/subscriber.go
rename to broker/subscriber.go
index 81ee6030..bdced69c 100644
--- a/server/subscriber.go
+++ b/broker/subscriber.go
@@ -1,4 +1,4 @@
-package server
+package broker
 
 import (
 	"fmt"
@@ -8,7 +8,8 @@ import (
 )
 
 const (
-	subSig = "func(context.Context, interface{}) error"
+	messageSig  = "func(broker.Message) error"
+	messagesSig = "func([]broker.Message) error"
 )
 
 // Precompute the reflect type for error. Can't use error directly
@@ -31,31 +32,31 @@ func isExportedOrBuiltinType(t reflect.Type) bool {
 	return isExported(t.Name()) || t.PkgPath() == ""
 }
 
-// ValidateSubscriber func signature
-func ValidateSubscriber(sub Subscriber) error {
-	typ := reflect.TypeOf(sub.Subscriber())
+// IsValidHandler func signature
+func IsValidHandler(sub interface{}) error {
+	typ := reflect.TypeOf(sub)
 	var argType reflect.Type
 	switch typ.Kind() {
 	case reflect.Func:
 		name := "Func"
 		switch typ.NumIn() {
-		case 2:
-			argType = typ.In(1)
+		case 1:
+			argType = typ.In(0)
 		default:
-			return fmt.Errorf("subscriber %v takes wrong number of args: %v required signature %s", name, typ.NumIn(), subSig)
+			return fmt.Errorf("subscriber %v takes wrong number of args: %v required signature %s", name, typ.NumIn(), messageSig)
 		}
 		if !isExportedOrBuiltinType(argType) {
 			return fmt.Errorf("subscriber %v argument type not exported: %v", name, argType)
 		}
 		if typ.NumOut() != 1 {
 			return fmt.Errorf("subscriber %v has wrong number of return values: %v require signature %s",
-				name, typ.NumOut(), subSig)
+				name, typ.NumOut(), messageSig)
 		}
 		if returnType := typ.Out(0); returnType != typeOfError {
 			return fmt.Errorf("subscriber %v returns %v not error", name, returnType.String())
 		}
 	default:
-		hdlr := reflect.ValueOf(sub.Subscriber())
+		hdlr := reflect.ValueOf(sub)
 		name := reflect.Indirect(hdlr).Type().Name()
 
 		for m := 0; m < typ.NumMethod(); m++ {
@@ -65,7 +66,7 @@ func ValidateSubscriber(sub Subscriber) error {
 				argType = method.Type.In(2)
 			default:
 				return fmt.Errorf("subscriber %v.%v takes wrong number of args: %v required signature %s",
-					name, method.Name, method.Type.NumIn(), subSig)
+					name, method.Name, method.Type.NumIn(), messageSig)
 			}
 
 			if !isExportedOrBuiltinType(argType) {
@@ -74,7 +75,7 @@ func ValidateSubscriber(sub Subscriber) error {
 			if method.Type.NumOut() != 1 {
 				return fmt.Errorf(
 					"subscriber %v.%v has wrong number of return values: %v require signature %s",
-					name, method.Name, method.Type.NumOut(), subSig)
+					name, method.Name, method.Type.NumOut(), messageSig)
 			}
 			if returnType := method.Type.Out(0); returnType != typeOfError {
 				return fmt.Errorf("subscriber %v.%v returns %v not error", name, method.Name, returnType.String())
diff --git a/client/client.go b/client/client.go
index 4925fe93..30cb04b3 100644
--- a/client/client.go
+++ b/client/client.go
@@ -29,40 +29,24 @@ var (
 )
 
 // Client is the interface used to make requests to services.
-// It supports Request/Response via Transport and Publishing via the Broker.
 // It also supports bidirectional streaming of requests.
 type Client interface {
 	Name() string
 	Init(opts ...Option) error
 	Options() Options
-	NewMessage(topic string, msg interface{}, opts ...MessageOption) Message
 	NewRequest(service string, endpoint string, req interface{}, opts ...RequestOption) Request
 	Call(ctx context.Context, req Request, rsp interface{}, opts ...CallOption) error
 	Stream(ctx context.Context, req Request, opts ...CallOption) (Stream, error)
-	Publish(ctx context.Context, msg Message, opts ...PublishOption) error
-	BatchPublish(ctx context.Context, msg []Message, opts ...PublishOption) error
 	String() string
 }
 
 type (
-	FuncCall         func(ctx context.Context, req Request, rsp interface{}, opts ...CallOption) error
-	HookCall         func(next FuncCall) FuncCall
-	FuncStream       func(ctx context.Context, req Request, opts ...CallOption) (Stream, error)
-	HookStream       func(next FuncStream) FuncStream
-	FuncPublish      func(ctx context.Context, msg Message, opts ...PublishOption) error
-	HookPublish      func(next FuncPublish) FuncPublish
-	FuncBatchPublish func(ctx context.Context, msg []Message, opts ...PublishOption) error
-	HookBatchPublish func(next FuncBatchPublish) FuncBatchPublish
+	FuncCall   func(ctx context.Context, req Request, rsp interface{}, opts ...CallOption) error
+	HookCall   func(next FuncCall) FuncCall
+	FuncStream func(ctx context.Context, req Request, opts ...CallOption) (Stream, error)
+	HookStream func(next FuncStream) FuncStream
 )
 
-// Message is the interface for publishing asynchronously
-type Message interface {
-	Topic() string
-	Payload() interface{}
-	ContentType() string
-	Metadata() metadata.Metadata
-}
-
 // Request is the interface for a synchronous request used by Call or Stream
 type Request interface {
 	// The service to call
@@ -121,11 +105,5 @@ type Option func(*Options)
 // CallOption used by Call or Stream
 type CallOption func(*CallOptions)
 
-// PublishOption used by Publish
-type PublishOption func(*PublishOptions)
-
-// MessageOption used by NewMessage
-type MessageOption func(*MessageOptions)
-
 // RequestOption used by NewRequest
 type RequestOption func(*RequestOptions)
diff --git a/client/context.go b/client/context.go
index 539e61a1..b5e6d95d 100644
--- a/client/context.go
+++ b/client/context.go
@@ -32,16 +32,6 @@ func NewContext(ctx context.Context, c Client) context.Context {
 	return context.WithValue(ctx, clientKey{}, c)
 }
 
-// SetPublishOption returns a function to setup a context with given value
-func SetPublishOption(k, v interface{}) PublishOption {
-	return func(o *PublishOptions) {
-		if o.Context == nil {
-			o.Context = context.Background()
-		}
-		o.Context = context.WithValue(o.Context, k, v)
-	}
-}
-
 // SetCallOption returns a function to setup a context with given value
 func SetCallOption(k, v interface{}) CallOption {
 	return func(o *CallOptions) {
diff --git a/client/context_test.go b/client/context_test.go
index e562529e..ced09a78 100644
--- a/client/context_test.go
+++ b/client/context_test.go
@@ -39,17 +39,6 @@ func TestNewNilContext(t *testing.T) {
 	}
 }
 
-func TestSetPublishOption(t *testing.T) {
-	type key struct{}
-	o := SetPublishOption(key{}, "test")
-	opts := &PublishOptions{}
-	o(opts)
-
-	if v, ok := opts.Context.Value(key{}).(string); !ok || v == "" {
-		t.Fatal("SetPublishOption not works")
-	}
-}
-
 func TestSetCallOption(t *testing.T) {
 	type key struct{}
 	o := SetCallOption(key{}, "test")
diff --git a/client/noop.go b/client/noop.go
index 4d1d446a..6623c70f 100644
--- a/client/noop.go
+++ b/client/noop.go
@@ -3,11 +3,9 @@ package client
 import (
 	"context"
 	"fmt"
-	"os"
 	"strconv"
 	"time"
 
-	"go.unistack.org/micro/v4/broker"
 	"go.unistack.org/micro/v4/codec"
 	"go.unistack.org/micro/v4/errors"
 	"go.unistack.org/micro/v4/metadata"
@@ -23,17 +21,9 @@ var DefaultCodecs = map[string]codec.Codec{
 }
 
 type noopClient struct {
-	funcPublish      FuncPublish
-	funcBatchPublish FuncBatchPublish
-	funcCall         FuncCall
-	funcStream       FuncStream
-	opts             Options
-}
-
-type noopMessage struct {
-	topic   string
-	payload interface{}
-	opts    MessageOptions
+	funcCall   FuncCall
+	funcStream FuncStream
+	opts       Options
 }
 
 type noopRequest struct {
@@ -52,8 +42,6 @@ func NewClient(opts ...Option) Client {
 
 	n.funcCall = n.fnCall
 	n.funcStream = n.fnStream
-	n.funcPublish = n.fnPublish
-	n.funcBatchPublish = n.fnBatchPublish
 
 	return n
 }
@@ -158,32 +146,6 @@ func (n *noopStream) CloseSend() error {
 	return n.err
 }
 
-func (n *noopMessage) Topic() string {
-	return n.topic
-}
-
-func (n *noopMessage) Payload() interface{} {
-	return n.payload
-}
-
-func (n *noopMessage) ContentType() string {
-	return n.opts.ContentType
-}
-
-func (n *noopMessage) Metadata() metadata.Metadata {
-	return n.opts.Metadata
-}
-
-func (n *noopClient) newCodec(contentType string) (codec.Codec, error) {
-	if cf, ok := n.opts.Codecs[contentType]; ok {
-		return cf, nil
-	}
-	if cf, ok := DefaultCodecs[contentType]; ok {
-		return cf, nil
-	}
-	return nil, codec.ErrUnknownContentType
-}
-
 func (n *noopClient) Init(opts ...Option) error {
 	for _, o := range opts {
 		o(&n.opts)
@@ -191,8 +153,6 @@ func (n *noopClient) Init(opts ...Option) error {
 
 	n.funcCall = n.fnCall
 	n.funcStream = n.fnStream
-	n.funcPublish = n.fnPublish
-	n.funcBatchPublish = n.fnBatchPublish
 
 	n.opts.Hooks.EachPrev(func(hook options.Hook) {
 		switch h := hook.(type) {
@@ -200,10 +160,6 @@ func (n *noopClient) Init(opts ...Option) error {
 			n.funcCall = h(n.funcCall)
 		case HookStream:
 			n.funcStream = h(n.funcStream)
-		case HookPublish:
-			n.funcPublish = h(n.funcPublish)
-		case HookBatchPublish:
-			n.funcBatchPublish = h(n.funcBatchPublish)
 		}
 	})
 
@@ -376,11 +332,6 @@ func (n *noopClient) NewRequest(service, endpoint string, _ interface{}, _ ...Re
 	return &noopRequest{service: service, endpoint: endpoint}
 }
 
-func (n *noopClient) NewMessage(topic string, msg interface{}, opts ...MessageOption) Message {
-	options := NewMessageOptions(append([]MessageOption{MessageContentType(n.opts.ContentType)}, opts...)...)
-	return &noopMessage{topic: topic, payload: msg, opts: options}
-}
-
 func (n *noopClient) Stream(ctx context.Context, req Request, opts ...CallOption) (Stream, error) {
 	ts := time.Now()
 	n.opts.Meter.Counter(semconv.ClientRequestInflight, "endpoint", req.Endpoint()).Inc()
@@ -549,90 +500,3 @@ func (n *noopClient) fnStream(ctx context.Context, req Request, opts ...CallOpti
 func (n *noopClient) stream(ctx context.Context, _ string, _ Request, _ CallOptions) (Stream, error) {
 	return &noopStream{ctx: ctx}, nil
 }
-
-func (n *noopClient) BatchPublish(ctx context.Context, ps []Message, opts ...PublishOption) error {
-	return n.funcBatchPublish(ctx, ps, opts...)
-}
-
-func (n *noopClient) fnBatchPublish(ctx context.Context, ps []Message, opts ...PublishOption) error {
-	return n.publish(ctx, ps, opts...)
-}
-
-func (n *noopClient) Publish(ctx context.Context, p Message, opts ...PublishOption) error {
-	return n.funcPublish(ctx, p, opts...)
-}
-
-func (n *noopClient) fnPublish(ctx context.Context, p Message, opts ...PublishOption) error {
-	return n.publish(ctx, []Message{p}, opts...)
-}
-
-func (n *noopClient) publish(ctx context.Context, ps []Message, opts ...PublishOption) error {
-	options := NewPublishOptions(opts...)
-
-	msgs := make([]*broker.Message, 0, len(ps))
-
-	// get proxy
-	exchange := ""
-	if v, ok := os.LookupEnv("MICRO_PROXY"); ok {
-		exchange = v
-	}
-	// get the exchange
-	if len(options.Exchange) > 0 {
-		exchange = options.Exchange
-	}
-
-	omd, ok := metadata.FromOutgoingContext(ctx)
-	if !ok {
-		omd = metadata.New(0)
-	}
-
-	for _, p := range ps {
-		md := metadata.Copy(omd)
-		topic := p.Topic()
-		if len(exchange) > 0 {
-			topic = exchange
-		}
-		md[metadata.HeaderTopic] = topic
-		iter := p.Metadata().Iterator()
-		var k, v string
-		for iter.Next(&k, &v) {
-			md.Set(k, v)
-		}
-
-		md[metadata.HeaderContentType] = p.ContentType()
-
-		var body []byte
-
-		// passed in raw data
-		if d, ok := p.Payload().(*codec.Frame); ok {
-			body = d.Data
-		} else {
-			// use codec for payload
-			cf, err := n.newCodec(p.ContentType())
-			if err != nil {
-				return errors.InternalServerError("go.micro.client", "%s", err)
-			}
-
-			// set the body
-			b, err := cf.Marshal(p.Payload())
-			if err != nil {
-				return errors.InternalServerError("go.micro.client", "%s", err)
-			}
-			body = b
-		}
-
-		msgs = append(msgs, &broker.Message{Header: md, Body: body})
-	}
-
-	if len(msgs) == 1 {
-		return n.opts.Broker.Publish(ctx, msgs[0].Header[metadata.HeaderTopic], msgs[0],
-			broker.PublishContext(options.Context),
-			broker.PublishBodyOnly(options.BodyOnly),
-		)
-	}
-
-	return n.opts.Broker.BatchPublish(ctx, msgs,
-		broker.PublishContext(options.Context),
-		broker.PublishBodyOnly(options.BodyOnly),
-	)
-}
diff --git a/client/noop_test.go b/client/noop_test.go
deleted file mode 100644
index cc05204c..00000000
--- a/client/noop_test.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package client
-
-import (
-	"context"
-	"testing"
-)
-
-type testHook struct {
-	f bool
-}
-
-func (t *testHook) Publish(fn FuncPublish) FuncPublish {
-	return func(ctx context.Context, msg Message, opts ...PublishOption) error {
-		t.f = true
-		return fn(ctx, msg, opts...)
-	}
-}
-
-func TestNoopHook(t *testing.T) {
-	h := &testHook{}
-
-	c := NewClient(Hooks(HookPublish(h.Publish)))
-
-	if err := c.Init(); err != nil {
-		t.Fatal(err)
-	}
-
-	if err := c.Publish(context.TODO(), c.NewMessage("", nil, MessageContentType("application/octet-stream"))); err != nil {
-		t.Fatal(err)
-	}
-
-	if !h.f {
-		t.Fatal("hook not works")
-	}
-}
diff --git a/client/options.go b/client/options.go
index fba8bd83..da6f1fc3 100644
--- a/client/options.go
+++ b/client/options.go
@@ -137,43 +137,6 @@ func Context(ctx context.Context) Option {
 	}
 }
 
-// NewPublishOptions create new PublishOptions struct from option
-func NewPublishOptions(opts ...PublishOption) PublishOptions {
-	options := PublishOptions{}
-	for _, o := range opts {
-		o(&options)
-	}
-	return options
-}
-
-// PublishOptions holds publish options
-type PublishOptions struct {
-	// Context used for external options
-	Context context.Context
-	// Exchange topic exchange name
-	Exchange string
-	// BodyOnly will publish only message body
-	BodyOnly bool
-}
-
-// NewMessageOptions creates message options struct
-func NewMessageOptions(opts ...MessageOption) MessageOptions {
-	options := MessageOptions{Metadata: metadata.New(1)}
-	for _, o := range opts {
-		o(&options)
-	}
-	return options
-}
-
-// MessageOptions holds client message options
-type MessageOptions struct {
-	// Metadata additional metadata
-	Metadata metadata.Metadata
-	// ContentType specify content-type of message
-	// deprecated
-	ContentType string
-}
-
 // NewRequestOptions creates new RequestOptions struct
 func NewRequestOptions(opts ...RequestOption) RequestOptions {
 	options := RequestOptions{}
@@ -374,43 +337,6 @@ func DialTimeout(d time.Duration) Option {
 	}
 }
 
-// WithExchange sets the exchange to route a message through
-// Deprecated
-func WithExchange(e string) PublishOption {
-	return func(o *PublishOptions) {
-		o.Exchange = e
-	}
-}
-
-// PublishExchange sets the exchange to route a message through
-func PublishExchange(e string) PublishOption {
-	return func(o *PublishOptions) {
-		o.Exchange = e
-	}
-}
-
-// WithBodyOnly publish only message body
-// DERECATED
-func WithBodyOnly(b bool) PublishOption {
-	return func(o *PublishOptions) {
-		o.BodyOnly = b
-	}
-}
-
-// PublishBodyOnly publish only message body
-func PublishBodyOnly(b bool) PublishOption {
-	return func(o *PublishOptions) {
-		o.BodyOnly = b
-	}
-}
-
-// PublishContext sets the context in publish options
-func PublishContext(ctx context.Context) PublishOption {
-	return func(o *PublishOptions) {
-		o.Context = ctx
-	}
-}
-
 // WithContextDialer pass ContextDialer to client call
 func WithContextDialer(fn func(context.Context, string) (net.Conn, error)) CallOption {
 	return func(o *CallOptions) {
@@ -522,30 +448,6 @@ func WithSelectOptions(sops ...selector.SelectOption) CallOption {
 	}
 }
 
-// WithMessageContentType sets the message content type
-// Deprecated
-func WithMessageContentType(ct string) MessageOption {
-	return func(o *MessageOptions) {
-		o.Metadata.Set(metadata.HeaderContentType, ct)
-		o.ContentType = ct
-	}
-}
-
-// MessageContentType sets the message content type
-func MessageContentType(ct string) MessageOption {
-	return func(o *MessageOptions) {
-		o.Metadata.Set(metadata.HeaderContentType, ct)
-		o.ContentType = ct
-	}
-}
-
-// MessageMetadata sets the message metadata
-func MessageMetadata(k, v string) MessageOption {
-	return func(o *MessageOptions) {
-		o.Metadata.Set(k, v)
-	}
-}
-
 // StreamingRequest specifies that request is streaming
 func StreamingRequest(b bool) RequestOption {
 	return func(o *RequestOptions) {
diff --git a/codec/frame.proto b/codec/frame.proto
index 69dc556a..8a2c2349 100644
--- a/codec/frame.proto
+++ b/codec/frame.proto
@@ -17,7 +17,7 @@ syntax = "proto3";
 package micro.codec;
 
 option cc_enable_arenas = true;
-option go_package = "go.unistack.org/micro/v3/codec;codec";
+option go_package = "go.unistack.org/micro/v4/codec;codec";
 option java_multiple_files = true;
 option java_outer_classname = "MicroCodec";
 option java_package = "micro.codec";
diff --git a/codec/noop.go b/codec/noop.go
index 76d21d93..3565bc8f 100644
--- a/codec/noop.go
+++ b/codec/noop.go
@@ -3,7 +3,7 @@ package codec
 import (
 	"encoding/json"
 
-	codecpb "go.unistack.org/micro-proto/v3/codec"
+	codecpb "go.unistack.org/micro-proto/v4/codec"
 )
 
 type noopCodec struct {
diff --git a/errors/errors.proto b/errors/errors.proto
index 76164b86..e95d12d6 100644
--- a/errors/errors.proto
+++ b/errors/errors.proto
@@ -17,7 +17,7 @@ syntax = "proto3";
 package micro.errors;
 
 option cc_enable_arenas = true;
-option go_package = "go.unistack.org/micro/v3/errors;errors";
+option go_package = "go.unistack.org/micro/v4/errors;errors";
 option java_multiple_files = true;
 option java_outer_classname = "MicroErrors";
 option java_package = "micro.errors";
diff --git a/event.go b/event.go
deleted file mode 100644
index 1e4116d6..00000000
--- a/event.go
+++ /dev/null
@@ -1,27 +0,0 @@
-package micro
-
-import (
-	"context"
-
-	"go.unistack.org/micro/v4/client"
-)
-
-// Event is used to publish messages to a topic
-type Event interface {
-	// Publish publishes a message to the event topic
-	Publish(ctx context.Context, msg interface{}, opts ...client.PublishOption) error
-}
-
-type event struct {
-	c     client.Client
-	topic string
-}
-
-// NewEvent creates a new event publisher
-func NewEvent(topic string, c client.Client) Event {
-	return &event{c, topic}
-}
-
-func (e *event) Publish(ctx context.Context, msg interface{}, opts ...client.PublishOption) error {
-	return e.c.Publish(ctx, e.c.NewMessage(e.topic, msg), opts...)
-}
diff --git a/go.mod b/go.mod
index 358b50f5..b3aded58 100644
--- a/go.mod
+++ b/go.mod
@@ -11,8 +11,9 @@ require (
 	github.com/matoous/go-nanoid v1.5.1
 	github.com/patrickmn/go-cache v2.1.0+incompatible
 	github.com/silas/dag v0.0.0-20220518035006-a7e85ada93c5
+	go.uber.org/atomic v1.11.0
 	go.uber.org/automaxprocs v1.6.0
-	go.unistack.org/micro-proto/v3 v3.4.1
+	go.unistack.org/micro-proto/v4 v4.1.0
 	golang.org/x/sync v0.10.0
 	google.golang.org/grpc v1.69.4
 	google.golang.org/protobuf v1.36.3
@@ -20,22 +21,12 @@ require (
 )
 
 require (
-	github.com/cilium/ebpf v0.16.0 // indirect
-	github.com/containerd/cgroups/v3 v3.0.4 // indirect
-	github.com/containerd/log v0.1.0 // indirect
-	github.com/coreos/go-systemd/v22 v22.5.0 // indirect
 	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
-	github.com/docker/go-units v0.5.0 // indirect
-	github.com/godbus/dbus/v5 v5.1.0 // indirect
-	github.com/moby/sys/userns v0.1.0 // indirect
-	github.com/opencontainers/runtime-spec v1.2.0 // indirect
+	github.com/kr/pretty v0.3.1 // indirect
 	github.com/pbnjay/memory v0.0.0-20210728143218-7b4eea64cf58 // indirect
 	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
 	github.com/rogpeppe/go-internal v1.13.1 // indirect
-	github.com/sirupsen/logrus v1.9.3 // indirect
 	github.com/stretchr/testify v1.10.0 // indirect
-	go.uber.org/goleak v1.3.0 // indirect
-	golang.org/x/exp v0.0.0-20241210194714-1829a127f884 // indirect
 	golang.org/x/net v0.34.0 // indirect
 	golang.org/x/sys v0.29.0 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20241216192217-9240e9c98484 // indirect
diff --git a/go.sum b/go.sum
index 72be286c..71ab9d91 100644
--- a/go.sum
+++ b/go.sum
@@ -2,39 +2,19 @@ dario.cat/mergo v1.0.1 h1:Ra4+bf83h2ztPIQYNP99R6m+Y7KfnARDfID+a+vLl4s=
 dario.cat/mergo v1.0.1/go.mod h1:uNxQE+84aUszobStD9th8a29P2fMDhsBdgRYvZOxGmk=
 github.com/DATA-DOG/go-sqlmock v1.5.2 h1:OcvFkGmslmlZibjAjaHm3L//6LiuBgolP7OputlJIzU=
 github.com/DATA-DOG/go-sqlmock v1.5.2/go.mod h1:88MAG/4G7SMwSE3CeA0ZKzrT5CiOU3OJ+JlNzwDqpNU=
-github.com/KimMachineGun/automemlimit v0.6.1 h1:ILa9j1onAAMadBsyyUJv5cack8Y1WT26yLj/V+ulKp8=
-github.com/KimMachineGun/automemlimit v0.6.1/go.mod h1:T7xYht7B8r6AG/AqFcUdc7fzd2bIdBKmepfP2S1svPY=
+github.com/KimMachineGun/automemlimit v0.7.0 h1:7G06p/dMSf7G8E6oq+f2uOPuVncFyIlDI/pBWK49u88=
+github.com/KimMachineGun/automemlimit v0.7.0/go.mod h1:QZxpHaGOQoYvFhv/r4u3U0JTC2ZcOwbSr11UZF46UBM=
 github.com/ash3in/uuidv8 v1.2.0 h1:2oogGdtCPwaVtyvPPGin4TfZLtOGE5F+W++E880G6SI=
 github.com/ash3in/uuidv8 v1.2.0/go.mod h1:BnU0wJBxnzdEKmVg4xckBkD+VZuecTFTUP3M0dWgyY4=
-github.com/cilium/ebpf v0.16.0 h1:+BiEnHL6Z7lXnlGUsXQPPAE7+kenAd4ES8MQ5min0Ok=
-github.com/cilium/ebpf v0.16.0/go.mod h1:L7u2Blt2jMM/vLAVgjxluxtBKlz3/GWjB0dMOEngfwE=
-github.com/containerd/cgroups/v3 v3.0.4 h1:2fs7l3P0Qxb1nKWuJNFiwhp2CqiKzho71DQkDrHJIo4=
-github.com/containerd/cgroups/v3 v3.0.4/go.mod h1:SA5DLYnXO8pTGYiAHXz94qvLQTKfVM5GEVisn4jpins=
-github.com/containerd/log v0.1.0 h1:TCJt7ioM2cr/tfR8GPbGf9/VRAX8D2B4PjzCpfX540I=
-github.com/containerd/log v0.1.0/go.mod h1:VRRf09a7mHDIRezVKTRCrOq78v577GXq3bSa3EhrzVo=
-github.com/coreos/go-systemd/v22 v22.5.0 h1:RrqgGjYQKalulkV8NGVIfkXQf6YYmOyiJKk8iXXhfZs=
-github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
-github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
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 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc h1:U9qPSI2PIWSS1VwoXQT9A3Wy9MM3WgvqSxFWenqJduM=
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/docker/go-units v0.5.0 h1:69rxXcBk27SvSaaxTtLh/8llcHD8vYHT7WSdRZ/jvr4=
-github.com/docker/go-units v0.5.0/go.mod h1:fgPhTUdO+D/Jk86RDLlptpiXQzgHJF7gydDDbaIK4Dk=
-github.com/go-quicktest/qt v1.101.0 h1:O1K29Txy5P2OK0dGo59b7b0LR6wKfIhttaAhHUyn7eI=
-github.com/go-quicktest/qt v1.101.0/go.mod h1:14Bz/f7NwaXPtdYEgzsx46kqSxVwTbzVZsDC26tQJow=
-github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
-github.com/godbus/dbus/v5 v5.1.0 h1:4KLkAxT3aOY8Li4FRJe/KvhoNFFxo0m6fNuFUO8QJUk=
-github.com/godbus/dbus/v5 v5.1.0/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
 github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
 github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
-github.com/josharian/native v1.1.0 h1:uuaP0hAbW7Y4l0ZRQ6C9zfb7Mg1mbFKry/xzDAfmtLA=
-github.com/josharian/native v1.1.0/go.mod h1:7X/raswPFr05uY3HiLlYeyQntB6OO7E/d2Cu7qoaN2w=
-github.com/jsimonetti/rtnetlink/v2 v2.0.1 h1:xda7qaHDSVOsADNouv7ukSuicKZO7GgVUCXxpaIEIlM=
-github.com/jsimonetti/rtnetlink/v2 v2.0.1/go.mod h1:7MoNYNbb3UaDHtF8udiJo/RH6VsTKP1pqKLUTVCvToE=
 github.com/kisielk/sqlstruct v0.0.0-20201105191214-5f3e10d3ab46/go.mod h1:yyMNCyc/Ib3bDTKd379tNMpB/7/H5TjM2Y9QJ5THLbE=
 github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
@@ -45,59 +25,44 @@ github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/matoous/go-nanoid v1.5.1 h1:aCjdvTyO9LLnTIi0fgdXhOPPvOHjpXN6Ik9DaNjIct4=
 github.com/matoous/go-nanoid v1.5.1/go.mod h1:zyD2a71IubI24efhpvkJz+ZwfwagzgSO6UNiFsZKN7U=
-github.com/mdlayher/netlink v1.7.2 h1:/UtM3ofJap7Vl4QWCPDGXY8d3GIY2UGSDbK+QWmY8/g=
-github.com/mdlayher/netlink v1.7.2/go.mod h1:xraEF7uJbxLhc5fpHL4cPe221LI2bdttWlU+ZGLfQSw=
-github.com/mdlayher/socket v0.4.1 h1:eM9y2/jlbs1M615oshPQOHZzj6R6wMT7bX5NPiQvn2U=
-github.com/mdlayher/socket v0.4.1/go.mod h1:cAqeGjoufqdxWkD7DkpyS+wcefOtmu5OQ8KuoJGIReA=
-github.com/moby/sys/userns v0.1.0 h1:tVLXkFOxVu9A64/yh59slHVv9ahO9UIev4JZusOLG/g=
-github.com/moby/sys/userns v0.1.0/go.mod h1:IHUYgu/kao6N8YZlp9Cf444ySSvCmDlmzUcYfDHOl28=
-github.com/opencontainers/runtime-spec v1.2.0 h1:z97+pHb3uELt/yiAWD691HNHQIF07bE7dzrbT927iTk=
-github.com/opencontainers/runtime-spec v1.2.0/go.mod h1:jwyrGlmzljRJv/Fgzds9SsS/C5hL+LL3ko9hs6T5lQ0=
 github.com/patrickmn/go-cache v2.1.0+incompatible h1:HRMgzkcYKYpi3C8ajMPV8OFXaaRUnok+kx1WdO15EQc=
 github.com/patrickmn/go-cache v2.1.0+incompatible/go.mod h1:3Qf8kWWT7OJRJbdiICTKqZju1ZixQ/KpMGzzAfe6+WQ=
 github.com/pbnjay/memory v0.0.0-20210728143218-7b4eea64cf58 h1:onHthvaw9LFnH4t2DcNVpwGmV9E1BkGknEliJkfwQj0=
 github.com/pbnjay/memory v0.0.0-20210728143218-7b4eea64cf58/go.mod h1:DXv8WO4yhMYhSNPKjeNKa5WY9YCIEBRbNzFFPJbWO6Y=
-github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
 github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 h1:Jamvg5psRIccs7FGNTlIRMkT8wgtp5eCXdBlqhYGL6U=
 github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prashantv/gostub v1.1.0 h1:BTyx3RfQjRHnUWaGF9oQos79AlQ5k8WNktv7VGvVH4g=
 github.com/prashantv/gostub v1.1.0/go.mod h1:A5zLQHz7ieHGG7is6LLXLz7I8+3LZzsrV0P1IAHhP5U=
+github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
 github.com/rogpeppe/go-internal v1.13.1 h1:KvO1DLK/DRN07sQ1LQKScxyZJuNnedQ5/wKSR38lUII=
 github.com/rogpeppe/go-internal v1.13.1/go.mod h1:uMEvuHeurkdAXX61udpOXGD/AzZDWNMNyH2VO9fmH0o=
 github.com/silas/dag v0.0.0-20220518035006-a7e85ada93c5 h1:G/FZtUu7a6NTWl3KUHMV9jkLAh/Rvtf03NWMHaEDl+E=
 github.com/silas/dag v0.0.0-20220518035006-a7e85ada93c5/go.mod h1:7RTUFBdIRC9nZ7/3RyRNH1bdqIShrDejd1YbLwgPS+I=
-github.com/sirupsen/logrus v1.9.3 h1:dueUQJ1C2q9oE3F7wvmSGAaVtTmUizReu6fjN8uqzbQ=
-github.com/sirupsen/logrus v1.9.3/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
-github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
 github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+go.uber.org/atomic v1.11.0 h1:ZvwS0R+56ePWxUNi+Atn9dWONBPp/AUETXlHW0DxSjE=
+go.uber.org/atomic v1.11.0/go.mod h1:LUxbIzbOniOlMKjJjyPfpl4v+PKK2cNJn91OQbhoJI0=
 go.uber.org/automaxprocs v1.6.0 h1:O3y2/QNTOdbF+e/dpXNNW7Rx2hZ4sTIPyybbxyNqTUs=
 go.uber.org/automaxprocs v1.6.0/go.mod h1:ifeIMSnPZuznNm6jmdzmU3/bfk01Fe2fotchwEFJ8r8=
-go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
-go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
-go.unistack.org/micro-proto/v3 v3.4.1 h1:UTjLSRz2YZuaHk9iSlVqqsA50JQNAEK2ZFboGqtEa9Q=
-go.unistack.org/micro-proto/v3 v3.4.1/go.mod h1:okx/cnOhzuCX0ggl/vToatbCupi0O44diiiLLsZ93Zo=
-golang.org/x/exp v0.0.0-20241210194714-1829a127f884 h1:Y/Mj/94zIQQGHVSv1tTtQBDaQaJe62U9bkDZKKyhPCU=
-golang.org/x/exp v0.0.0-20241210194714-1829a127f884/go.mod h1:qj5a5QZpwLU2NLQudwIN5koi3beDhSAlJwa67PuM98c=
-golang.org/x/net v0.33.0 h1:74SYHlV8BIgHIFC/LrYkOGIwL19eTYXQ5wc6TBuO36I=
-golang.org/x/net v0.33.0/go.mod h1:HXLR5J+9DxmrqMwG9qjGCxZ+zKXxBru04zlTvWlWuN4=
+go.unistack.org/micro-proto/v4 v4.1.0 h1:qPwL2n/oqh9RE3RTTDgt28XK3QzV597VugQPaw9lKUk=
+go.unistack.org/micro-proto/v4 v4.1.0/go.mod h1:ArmK7o+uFvxSY3dbJhKBBX4Pm1rhWdLEFf3LxBrMtec=
+golang.org/x/net v0.34.0 h1:Mb7Mrk043xzHgnRM88suvJFwzVrRfHEHJEl5/71CKw0=
+golang.org/x/net v0.34.0/go.mod h1:di0qlW3YNM5oh6GqDGQr92MyTozJPmybPK4Ev/Gm31k=
 golang.org/x/sync v0.10.0 h1:3NQrjDixjgGwUOCaF8w2+VYHv0Ve/vGYSbdkTa98gmQ=
 golang.org/x/sync v0.10.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
-golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.28.0 h1:Fksou7UEQUWlKvIdsqzJmUmCX3cZuD2+P3XyyzwMhlA=
-golang.org/x/sys v0.28.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
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+golang.org/x/sys v0.29.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/text v0.21.0 h1:zyQAAkrwaneQ066sspRyJaG9VNi/YJ1NfzcGB3hZ/qo=
 golang.org/x/text v0.21.0/go.mod h1:4IBbMaMmOPCJ8SecivzSH54+73PCFmPWxNTLm+vZkEQ=
 google.golang.org/genproto/googleapis/rpc v0.0.0-20241216192217-9240e9c98484 h1:Z7FRVJPSMaHQxD0uXU8WdgFh8PseLM8Q8NzhnpMrBhQ=
 google.golang.org/genproto/googleapis/rpc v0.0.0-20241216192217-9240e9c98484/go.mod h1:lcTa1sDdWEIHMWlITnIczmw5w60CF9ffkb8Z+DVmmjA=
-google.golang.org/grpc v1.69.2 h1:U3S9QEtbXC0bYNvRtcoklF3xGtLViumSYxWykJS+7AU=
-google.golang.org/grpc v1.69.2/go.mod h1:vyjdE6jLBI76dgpDojsFGNaHlxdjXN9ghpnd2o7JGZ4=
-google.golang.org/protobuf v1.36.1 h1:yBPeRvTftaleIgM3PZ/WBIZ7XM/eEYAaEyCwvyjq/gk=
-google.golang.org/protobuf v1.36.1/go.mod h1:9fA7Ob0pmnwhb644+1+CVWFRbNajQ6iRojtC/QF5bRE=
+google.golang.org/grpc v1.69.4 h1:MF5TftSMkd8GLw/m0KM6V8CMOCY6NZ1NQDPGFgbTt4A=
+google.golang.org/grpc v1.69.4/go.mod h1:vyjdE6jLBI76dgpDojsFGNaHlxdjXN9ghpnd2o7JGZ4=
+google.golang.org/protobuf v1.36.3 h1:82DV7MYdb8anAVi3qge1wSnMDrnKK7ebr+I0hHRN1BU=
+google.golang.org/protobuf v1.36.3/go.mod h1:9fA7Ob0pmnwhb644+1+CVWFRbNajQ6iRojtC/QF5bRE=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/logger/slog/slog_test.go b/logger/slog/slog_test.go
index 18a24297..e8e6d353 100644
--- a/logger/slog/slog_test.go
+++ b/logger/slog/slog_test.go
@@ -412,9 +412,10 @@ func Test_WithContextAttrFunc(t *testing.T) {
 			}
 			attrs := make([]interface{}, 0, 10)
 			for k, v := range md {
-				switch k {
-				case "X-Request-Id", "Phone", "External-Id", "Source-Service", "X-App-Install-Id", "Client-Id", "Client-Ip":
-					attrs = append(attrs, strings.ToLower(k), v)
+				key := strings.ToLower(k)
+				switch key {
+				case "x-request-id", "phone", "external-Id", "source-service", "x-app-install-id", "client-id", "client-ip":
+					attrs = append(attrs, key, v[0])
 				}
 			}
 			return attrs
diff --git a/metadata/context.go b/metadata/context.go
deleted file mode 100644
index 471b144a..00000000
--- a/metadata/context.go
+++ /dev/null
@@ -1,181 +0,0 @@
-//go:build !exclude
-
-// Package metadata is a way of defining message headers
-package metadata
-
-import (
-	"context"
-)
-
-type (
-	mdIncomingKey struct{}
-	mdOutgoingKey struct{}
-	mdKey         struct{}
-)
-
-// FromIncomingContext returns metadata from incoming ctx
-// returned metadata shoud not be modified or race condition happens
-func FromIncomingContext(ctx context.Context) (Metadata, bool) {
-	if ctx == nil {
-		return nil, false
-	}
-	md, ok := ctx.Value(mdIncomingKey{}).(*rawMetadata)
-	if !ok || md.md == nil {
-		return nil, false
-	}
-	return md.md, ok
-}
-
-// MustIncomingContext returns metadata from incoming ctx
-// returned metadata shoud not be modified or race condition happens.
-// If metadata not exists panics.
-func MustIncomingContext(ctx context.Context) Metadata {
-	md, ok := FromIncomingContext(ctx)
-	if !ok {
-		panic("missing metadata")
-	}
-	return md
-}
-
-// FromOutgoingContext returns metadata from outgoing ctx
-// returned metadata shoud not be modified or race condition happens
-func FromOutgoingContext(ctx context.Context) (Metadata, bool) {
-	if ctx == nil {
-		return nil, false
-	}
-	md, ok := ctx.Value(mdOutgoingKey{}).(*rawMetadata)
-	if !ok || md.md == nil {
-		return nil, false
-	}
-	return md.md, ok
-}
-
-// MustOutgoingContext returns metadata from outgoing ctx
-// returned metadata shoud not be modified or race condition happens.
-// If metadata not exists panics.
-func MustOutgoingContext(ctx context.Context) Metadata {
-	md, ok := FromOutgoingContext(ctx)
-	if !ok {
-		panic("missing metadata")
-	}
-	return md
-}
-
-// FromContext returns metadata from the given context
-// returned metadata shoud not be modified or race condition happens
-func FromContext(ctx context.Context) (Metadata, bool) {
-	if ctx == nil {
-		return nil, false
-	}
-	md, ok := ctx.Value(mdKey{}).(*rawMetadata)
-	if !ok || md.md == nil {
-		return nil, false
-	}
-	return md.md, ok
-}
-
-// MustContext returns metadata from the given context
-// returned metadata shoud not be modified or race condition happens
-func MustContext(ctx context.Context) Metadata {
-	md, ok := FromContext(ctx)
-	if !ok {
-		panic("missing metadata")
-	}
-	return md
-}
-
-// NewContext creates a new context with the given metadata
-func NewContext(ctx context.Context, md Metadata) context.Context {
-	if ctx == nil {
-		ctx = context.Background()
-	}
-	return context.WithValue(ctx, mdKey{}, &rawMetadata{md})
-}
-
-// SetOutgoingContext modify outgoing context with given metadata
-func SetOutgoingContext(ctx context.Context, md Metadata) bool {
-	if ctx == nil {
-		return false
-	}
-	if omd, ok := ctx.Value(mdOutgoingKey{}).(*rawMetadata); ok {
-		omd.md = md
-		return true
-	}
-	return false
-}
-
-// SetIncomingContext modify incoming context with given metadata
-func SetIncomingContext(ctx context.Context, md Metadata) bool {
-	if ctx == nil {
-		return false
-	}
-	if omd, ok := ctx.Value(mdIncomingKey{}).(*rawMetadata); ok {
-		omd.md = md
-		return true
-	}
-	return false
-}
-
-// NewIncomingContext creates a new context with incoming metadata attached
-func NewIncomingContext(ctx context.Context, md Metadata) context.Context {
-	if ctx == nil {
-		ctx = context.Background()
-	}
-	return context.WithValue(ctx, mdIncomingKey{}, &rawMetadata{md})
-}
-
-// NewOutgoingContext creates a new context with outcoming metadata attached
-func NewOutgoingContext(ctx context.Context, md Metadata) context.Context {
-	if ctx == nil {
-		ctx = context.Background()
-	}
-	return context.WithValue(ctx, mdOutgoingKey{}, &rawMetadata{md})
-}
-
-// AppendOutgoingContext apends new md to context
-func AppendOutgoingContext(ctx context.Context, kv ...string) context.Context {
-	md, ok := Pairs(kv...)
-	if !ok {
-		return ctx
-	}
-	omd, ok := FromOutgoingContext(ctx)
-	if !ok {
-		return NewOutgoingContext(ctx, md)
-	}
-	for k, v := range md {
-		omd.Set(k, v)
-	}
-	return ctx
-}
-
-// AppendIncomingContext apends new md to context
-func AppendIncomingContext(ctx context.Context, kv ...string) context.Context {
-	md, ok := Pairs(kv...)
-	if !ok {
-		return ctx
-	}
-	omd, ok := FromIncomingContext(ctx)
-	if !ok {
-		return NewIncomingContext(ctx, md)
-	}
-	for k, v := range md {
-		omd.Set(k, v)
-	}
-	return ctx
-}
-
-// AppendContext apends new md to context
-func AppendContext(ctx context.Context, kv ...string) context.Context {
-	md, ok := Pairs(kv...)
-	if !ok {
-		return ctx
-	}
-	omd, ok := FromContext(ctx)
-	if !ok {
-		return NewContext(ctx, md)
-	}
-	for k, v := range md {
-		omd.Set(k, v)
-	}
-	return ctx
-}
diff --git a/metadata/context_test.go b/metadata/context_test.go
deleted file mode 100644
index deaa020a..00000000
--- a/metadata/context_test.go
+++ /dev/null
@@ -1,140 +0,0 @@
-package metadata
-
-import (
-	"context"
-	"testing"
-)
-
-func TestFromNilContext(t *testing.T) {
-	// nolint: staticcheck
-	c, ok := FromContext(nil)
-	if ok || c != nil {
-		t.Fatal("FromContext not works")
-	}
-}
-
-func TestNewNilContext(t *testing.T) {
-	// nolint: staticcheck
-	ctx := NewContext(nil, New(0))
-
-	c, ok := FromContext(ctx)
-	if c == nil || !ok {
-		t.Fatal("NewContext not works")
-	}
-}
-
-func TestFromContext(t *testing.T) {
-	ctx := context.WithValue(context.TODO(), mdKey{}, &rawMetadata{New(0)})
-
-	c, ok := FromContext(ctx)
-	if c == nil || !ok {
-		t.Fatal("FromContext not works")
-	}
-}
-
-func TestNewContext(t *testing.T) {
-	ctx := NewContext(context.TODO(), New(0))
-
-	c, ok := FromContext(ctx)
-	if c == nil || !ok {
-		t.Fatal("NewContext not works")
-	}
-}
-
-func TestFromIncomingContext(t *testing.T) {
-	ctx := context.WithValue(context.TODO(), mdIncomingKey{}, &rawMetadata{New(0)})
-
-	c, ok := FromIncomingContext(ctx)
-	if c == nil || !ok {
-		t.Fatal("FromIncomingContext not works")
-	}
-}
-
-func TestFromOutgoingContext(t *testing.T) {
-	ctx := context.WithValue(context.TODO(), mdOutgoingKey{}, &rawMetadata{New(0)})
-
-	c, ok := FromOutgoingContext(ctx)
-	if c == nil || !ok {
-		t.Fatal("FromOutgoingContext not works")
-	}
-}
-
-func TestSetIncomingContext(t *testing.T) {
-	md := New(1)
-	md.Set("key", "val")
-	ctx := context.WithValue(context.TODO(), mdIncomingKey{}, &rawMetadata{})
-	if !SetIncomingContext(ctx, md) {
-		t.Fatal("SetIncomingContext not works")
-	}
-	md, ok := FromIncomingContext(ctx)
-	if md == nil || !ok {
-		t.Fatal("SetIncomingContext not works")
-	} else if v, ok := md.Get("key"); !ok || v != "val" {
-		t.Fatal("SetIncomingContext not works")
-	}
-}
-
-func TestSetOutgoingContext(t *testing.T) {
-	md := New(1)
-	md.Set("key", "val")
-	ctx := context.WithValue(context.TODO(), mdOutgoingKey{}, &rawMetadata{})
-	if !SetOutgoingContext(ctx, md) {
-		t.Fatal("SetOutgoingContext not works")
-	}
-	md, ok := FromOutgoingContext(ctx)
-	if md == nil || !ok {
-		t.Fatal("SetOutgoingContext not works")
-	} else if v, ok := md.Get("key"); !ok || v != "val" {
-		t.Fatal("SetOutgoingContext not works")
-	}
-}
-
-func TestNewIncomingContext(t *testing.T) {
-	md := New(1)
-	md.Set("key", "val")
-	ctx := NewIncomingContext(context.TODO(), md)
-
-	c, ok := FromIncomingContext(ctx)
-	if c == nil || !ok {
-		t.Fatal("NewIncomingContext not works")
-	}
-}
-
-func TestNewOutgoingContext(t *testing.T) {
-	md := New(1)
-	md.Set("key", "val")
-	ctx := NewOutgoingContext(context.TODO(), md)
-
-	c, ok := FromOutgoingContext(ctx)
-	if c == nil || !ok {
-		t.Fatal("NewOutgoingContext not works")
-	}
-}
-
-func TestAppendIncomingContext(t *testing.T) {
-	md := New(1)
-	md.Set("key1", "val1")
-	ctx := AppendIncomingContext(context.TODO(), "key2", "val2")
-
-	nmd, ok := FromIncomingContext(ctx)
-	if nmd == nil || !ok {
-		t.Fatal("AppendIncomingContext not works")
-	}
-	if v, ok := nmd.Get("key2"); !ok || v != "val2" {
-		t.Fatal("AppendIncomingContext not works")
-	}
-}
-
-func TestAppendOutgoingContext(t *testing.T) {
-	md := New(1)
-	md.Set("key1", "val1")
-	ctx := AppendOutgoingContext(context.TODO(), "key2", "val2")
-
-	nmd, ok := FromOutgoingContext(ctx)
-	if nmd == nil || !ok {
-		t.Fatal("AppendOutgoingContext not works")
-	}
-	if v, ok := nmd.Get("key2"); !ok || v != "val2" {
-		t.Fatal("AppendOutgoingContext not works")
-	}
-}
diff --git a/metadata/headers.go b/metadata/headers.go
new file mode 100644
index 00000000..7e670eee
--- /dev/null
+++ b/metadata/headers.go
@@ -0,0 +1,19 @@
+// Package metadata is a way of defining message headers
+package metadata
+
+var (
+	// HeaderTopic is the header name that contains topic name
+	HeaderTopic = "Micro-Topic"
+	// HeaderContentType specifies content type of message
+	HeaderContentType = "Content-Type"
+	// HeaderEndpoint specifies endpoint in service
+	HeaderEndpoint = "Micro-Endpoint"
+	// HeaderService specifies service
+	HeaderService = "Micro-Service"
+	// HeaderTimeout specifies timeout of operation
+	HeaderTimeout = "Micro-Timeout"
+	// HeaderAuthorization specifies Authorization header
+	HeaderAuthorization = "Authorization"
+	// HeaderXRequestID specifies request id
+	HeaderXRequestID = "X-Request-Id"
+)
diff --git a/metadata/metadata.go b/metadata/metadata.go
index f2729e73..abc8fd81 100644
--- a/metadata/metadata.go
+++ b/metadata/metadata.go
@@ -1,43 +1,462 @@
-//go:build !exclude
-
-// Package metadata is a way of defining message headers
 package metadata
 
 import (
+	"context"
+	"fmt"
 	"net/textproto"
 	"sort"
 	"strings"
 )
 
-var (
-	// HeaderTopic is the header name that contains topic name
-	HeaderTopic = "Micro-Topic"
-	// HeaderContentType specifies content type of message
-	HeaderContentType = "Content-Type"
-	// HeaderEndpoint specifies endpoint in service
-	HeaderEndpoint = "Micro-Endpoint"
-	// HeaderService specifies service
-	HeaderService = "Micro-Service"
-	// HeaderTimeout specifies timeout of operation
-	HeaderTimeout = "Micro-Timeout"
-	// HeaderAuthorization specifies Authorization header
-	HeaderAuthorization = "Authorization"
-	// HeaderXRequestID specifies request id
-	HeaderXRequestID = "X-Request-Id"
-)
-
-// Metadata is our way of representing request headers internally.
-// They're used at the RPC level and translate back and forth
-// from Transport headers.
-type Metadata map[string]string
-
-type rawMetadata struct {
-	md Metadata
-}
-
 // defaultMetadataSize used when need to init new Metadata
 var defaultMetadataSize = 2
 
+// Metadata is a mapping from metadata keys to values. Users should use the following
+// two convenience functions New and Pairs to generate Metadata.
+type Metadata map[string][]string
+
+// New creates an zero Metadata.
+func New(l int) Metadata {
+	if l == 0 {
+		l = defaultMetadataSize
+	}
+	md := make(Metadata, l)
+	return md
+}
+
+// NewWithMetadata creates an Metadata from a given key-value map.
+func NewWithMetadata(m map[string]string) Metadata {
+	md := make(Metadata, len(m))
+	for key, val := range m {
+		md[key] = append(md[key], val)
+	}
+	return md
+}
+
+// Pairs returns an Metadata formed by the mapping of key, value ...
+// Pairs panics if len(kv) is odd.
+func Pairs(kv ...string) Metadata {
+	if len(kv)%2 == 1 {
+		panic(fmt.Sprintf("metadata: Pairs got the odd number of input pairs for metadata: %d", len(kv)))
+	}
+	md := make(Metadata, len(kv)/2)
+	for i := 0; i < len(kv); i += 2 {
+		md[kv[i]] = append(md[kv[i]], kv[i+1])
+	}
+	return md
+}
+
+// Len returns the number of items in Metadata.
+func (md Metadata) Len() int {
+	return len(md)
+}
+
+// Copy returns a copy of Metadata.
+func Copy(src Metadata) Metadata {
+	out := make(Metadata, len(src))
+	for k, v := range src {
+		out[k] = copyOf(v)
+	}
+	return out
+}
+
+// Copy returns a copy of Metadata.
+func (md Metadata) Copy() Metadata {
+	out := make(Metadata, len(md))
+	for k, v := range md {
+		out[k] = copyOf(v)
+	}
+	return out
+}
+
+// AsHTTP1 returns a copy of Metadata
+// with CanonicalMIMEHeaderKey.
+func (md Metadata) AsHTTP1() map[string][]string {
+	out := make(map[string][]string, len(md))
+	for k, v := range md {
+		out[textproto.CanonicalMIMEHeaderKey(k)] = copyOf(v)
+	}
+	return out
+}
+
+// AsHTTP1 returns a copy of Metadata
+// with strings.ToLower.
+func (md Metadata) AsHTTP2() map[string][]string {
+	out := make(map[string][]string, len(md))
+	for k, v := range md {
+		out[strings.ToLower(k)] = copyOf(v)
+	}
+	return out
+}
+
+// CopyTo copies Metadata to out.
+func (md Metadata) CopyTo(out Metadata) {
+	for k, v := range md {
+		out[k] = copyOf(v)
+	}
+}
+
+// Get obtains the values for a given key.
+func (md Metadata) MustGet(k string) []string {
+	v, ok := md.Get(k)
+	if !ok {
+		panic("missing metadata key")
+	}
+	return v
+}
+
+// Get obtains the values for a given key.
+func (md Metadata) Get(k string) ([]string, bool) {
+	v, ok := md[k]
+	if !ok {
+		v, ok = md[strings.ToLower(k)]
+	}
+	if !ok {
+		v, ok = md[textproto.CanonicalMIMEHeaderKey(k)]
+	}
+	return v, ok
+}
+
+// MustGetJoined obtains the values for a given key
+// with joined values with "," symbol
+func (md Metadata) MustGetJoined(k string) string {
+	v, ok := md.GetJoined(k)
+	if !ok {
+		panic("missing metadata key")
+	}
+	return v
+}
+
+// GetJoined obtains the values for a given key
+// with joined values with "," symbol
+func (md Metadata) GetJoined(k string) (string, bool) {
+	v, ok := md.Get(k)
+	if !ok {
+		return "", ok
+	}
+	return strings.Join(v, ","), true
+}
+
+// Set sets the value of a given key with a slice of values.
+func (md Metadata) Add(key string, vals ...string) {
+	if len(vals) == 0 {
+		return
+	}
+	md[key] = vals
+}
+
+// Set sets the value of a given key with a slice of values.
+func (md Metadata) Set(kvs ...string) {
+	if len(kvs)%2 == 1 {
+		panic(fmt.Sprintf("metadata: Set got an odd number of input pairs for metadata: %d", len(kvs)))
+	}
+
+	for i := 0; i < len(kvs); i += 2 {
+		md[kvs[i]] = append(md[kvs[i]], kvs[i+1])
+	}
+}
+
+// Append adds the values to key k, not overwriting what was already stored at
+// that key.
+func (md Metadata) Append(key string, vals ...string) {
+	if len(vals) == 0 {
+		return
+	}
+	md[key] = append(md[key], vals...)
+}
+
+// Del removes the values for a given keys k.
+func (md Metadata) Del(k ...string) {
+	for i := range k {
+		delete(md, k[i])
+		delete(md, strings.ToLower(k[i]))
+		delete(md, textproto.CanonicalMIMEHeaderKey(k[i]))
+	}
+}
+
+// Join joins any number of Metadatas into a single Metadata.
+//
+// The order of values for each key is determined by the order in which the Metadatas
+// containing those values are presented to Join.
+func Join(mds ...Metadata) Metadata {
+	out := Metadata{}
+	for _, Metadata := range mds {
+		for k, v := range Metadata {
+			out[k] = append(out[k], v...)
+		}
+	}
+	return out
+}
+
+type (
+	metadataIncomingKey struct{}
+	metadataOutgoingKey struct{}
+	metadataCurrentKey  struct{}
+)
+
+// NewContext creates a new context with Metadata attached. Metadata must
+// not be modified after calling this function.
+func NewContext(ctx context.Context, md Metadata) context.Context {
+	return context.WithValue(ctx, metadataCurrentKey{}, rawMetadata{md: md})
+}
+
+// NewIncomingContext creates a new context with incoming Metadata attached. Metadata must
+// not be modified after calling this function.
+func NewIncomingContext(ctx context.Context, md Metadata) context.Context {
+	return context.WithValue(ctx, metadataIncomingKey{}, rawMetadata{md: md})
+}
+
+// NewOutgoingContext creates a new context with outgoing Metadata attached. If used
+// in conjunction with AppendOutgoingContext, NewOutgoingContext will
+// overwrite any previously-appended metadata. Metadata must not be modified after
+// calling this function.
+func NewOutgoingContext(ctx context.Context, md Metadata) context.Context {
+	return context.WithValue(ctx, metadataOutgoingKey{}, rawMetadata{md: md})
+}
+
+// AppendContext returns a new context with the provided kv merged
+// with any existing metadata in the context. Please refer to the documentation
+// of Pairs for a description of kv.
+func AppendContext(ctx context.Context, kv ...string) context.Context {
+	if len(kv)%2 == 1 {
+		panic(fmt.Sprintf("metadata: AppendContext got an odd number of input pairs for metadata: %d", len(kv)))
+	}
+	md, _ := ctx.Value(metadataCurrentKey{}).(rawMetadata)
+	added := make([][]string, len(md.added)+1)
+	copy(added, md.added)
+	kvCopy := make([]string, 0, len(kv))
+	for i := 0; i < len(kv); i += 2 {
+		kvCopy = append(kvCopy, strings.ToLower(kv[i]), kv[i+1])
+	}
+	added[len(added)-1] = kvCopy
+	return context.WithValue(ctx, metadataCurrentKey{}, rawMetadata{md: md.md, added: added})
+}
+
+// AppendIncomingContext returns a new context with the provided kv merged
+// with any existing metadata in the context. Please refer to the documentation
+// of Pairs for a description of kv.
+func AppendIncomingContext(ctx context.Context, kv ...string) context.Context {
+	if len(kv)%2 == 1 {
+		panic(fmt.Sprintf("metadata: AppendIncomingContext got an odd number of input pairs for metadata: %d", len(kv)))
+	}
+	md, _ := ctx.Value(metadataIncomingKey{}).(rawMetadata)
+	added := make([][]string, len(md.added)+1)
+	copy(added, md.added)
+	kvCopy := make([]string, 0, len(kv))
+	for i := 0; i < len(kv); i += 2 {
+		kvCopy = append(kvCopy, strings.ToLower(kv[i]), kv[i+1])
+	}
+	added[len(added)-1] = kvCopy
+	return context.WithValue(ctx, metadataIncomingKey{}, rawMetadata{md: md.md, added: added})
+}
+
+// AppendOutgoingContext returns a new context with the provided kv merged
+// with any existing metadata in the context. Please refer to the documentation
+// of Pairs for a description of kv.
+func AppendOutgoingContext(ctx context.Context, kv ...string) context.Context {
+	if len(kv)%2 == 1 {
+		panic(fmt.Sprintf("metadata: AppendOutgoingContext got an odd number of input pairs for metadata: %d", len(kv)))
+	}
+	md, _ := ctx.Value(metadataOutgoingKey{}).(rawMetadata)
+	added := make([][]string, len(md.added)+1)
+	copy(added, md.added)
+	kvCopy := make([]string, 0, len(kv))
+	for i := 0; i < len(kv); i += 2 {
+		kvCopy = append(kvCopy, strings.ToLower(kv[i]), kv[i+1])
+	}
+	added[len(added)-1] = kvCopy
+	return context.WithValue(ctx, metadataOutgoingKey{}, rawMetadata{md: md.md, added: added})
+}
+
+// FromContext returns the metadata in ctx if it exists.
+func FromContext(ctx context.Context) (Metadata, bool) {
+	raw, ok := ctx.Value(metadataCurrentKey{}).(rawMetadata)
+	if !ok {
+		return nil, false
+	}
+	metadataSize := len(raw.md)
+	for i := range raw.added {
+		metadataSize += len(raw.added[i]) / 2
+	}
+
+	out := make(Metadata, metadataSize)
+	for k, v := range raw.md {
+		out[k] = copyOf(v)
+	}
+	for _, added := range raw.added {
+		if len(added)%2 == 1 {
+			panic(fmt.Sprintf("metadata: FromContext got an odd number of input pairs for metadata: %d", len(added)))
+		}
+
+		for i := 0; i < len(added); i += 2 {
+			out[added[i]] = append(out[added[i]], added[i+1])
+		}
+	}
+	return out, true
+}
+
+// MustContext returns the metadata in ctx.
+func MustContext(ctx context.Context) Metadata {
+	md, ok := FromContext(ctx)
+	if !ok {
+		panic("missing metadata")
+	}
+	return md
+}
+
+// FromIncomingContext returns the incoming metadata in ctx if it exists.
+func FromIncomingContext(ctx context.Context) (Metadata, bool) {
+	raw, ok := ctx.Value(metadataIncomingKey{}).(rawMetadata)
+	if !ok {
+		return nil, false
+	}
+	metadataSize := len(raw.md)
+	for i := range raw.added {
+		metadataSize += len(raw.added[i]) / 2
+	}
+
+	out := make(Metadata, metadataSize)
+	for k, v := range raw.md {
+		out[k] = copyOf(v)
+	}
+	for _, added := range raw.added {
+		if len(added)%2 == 1 {
+			panic(fmt.Sprintf("metadata: FromIncomingContext got an odd number of input pairs for metadata: %d", len(added)))
+		}
+
+		for i := 0; i < len(added); i += 2 {
+			out[added[i]] = append(out[added[i]], added[i+1])
+		}
+	}
+	return out, true
+}
+
+// MustIncomingContext returns the incoming metadata in ctx.
+func MustIncomingContext(ctx context.Context) Metadata {
+	md, ok := FromIncomingContext(ctx)
+	if !ok {
+		panic("missing metadata")
+	}
+	return md
+}
+
+// ValueFromIncomingContext returns the metadata value corresponding to the metadata
+// key from the incoming metadata if it exists. Keys are matched in a case insensitive
+// manner.
+func ValueFromIncomingContext(ctx context.Context, key string) []string {
+	raw, ok := ctx.Value(metadataIncomingKey{}).(rawMetadata)
+	if !ok {
+		return nil
+	}
+
+	if v, ok := raw.md[key]; ok {
+		return copyOf(v)
+	}
+	for k, v := range raw.md {
+		// Case insensitive comparison: Metadata is a map, and there's no guarantee
+		// that the Metadata attached to the context is created using our helper
+		// functions.
+		if strings.EqualFold(k, key) {
+			return copyOf(v)
+		}
+	}
+	return nil
+}
+
+// ValueFromCurrentContext returns the metadata value corresponding to the metadata
+// key from the incoming metadata if it exists. Keys are matched in a case insensitive
+// manner.
+func ValueFromCurrentContext(ctx context.Context, key string) []string {
+	md, ok := ctx.Value(metadataCurrentKey{}).(rawMetadata)
+	if !ok {
+		return nil
+	}
+
+	if v, ok := md.md[key]; ok {
+		return copyOf(v)
+	}
+	for k, v := range md.md {
+		// Case insensitive comparison: Metadata is a map, and there's no guarantee
+		// that the Metadata attached to the context is created using our helper
+		// functions.
+		if strings.EqualFold(k, key) {
+			return copyOf(v)
+		}
+	}
+	return nil
+}
+
+// MustOutgoingContext returns the outgoing metadata in ctx.
+func MustOutgoingContext(ctx context.Context) Metadata {
+	md, ok := FromOutgoingContext(ctx)
+	if !ok {
+		panic("missing metadata")
+	}
+	return md
+}
+
+// ValueFromOutgoingContext returns the metadata value corresponding to the metadata
+// key from the incoming metadata if it exists. Keys are matched in a case insensitive
+// manner.
+func ValueFromOutgoingContext(ctx context.Context, key string) []string {
+	md, ok := ctx.Value(metadataOutgoingKey{}).(rawMetadata)
+	if !ok {
+		return nil
+	}
+
+	if v, ok := md.md[key]; ok {
+		return copyOf(v)
+	}
+	for k, v := range md.md {
+		// Case insensitive comparison: Metadata is a map, and there's no guarantee
+		// that the Metadata attached to the context is created using our helper
+		// functions.
+		if strings.EqualFold(k, key) {
+			return copyOf(v)
+		}
+	}
+	return nil
+}
+
+func copyOf(v []string) []string {
+	vals := make([]string, len(v))
+	copy(vals, v)
+	return vals
+}
+
+// FromOutgoingContext returns the outgoing metadata in ctx if it exists.
+func FromOutgoingContext(ctx context.Context) (Metadata, bool) {
+	raw, ok := ctx.Value(metadataOutgoingKey{}).(rawMetadata)
+	if !ok {
+		return nil, false
+	}
+
+	metadataSize := len(raw.md)
+	for i := range raw.added {
+		metadataSize += len(raw.added[i]) / 2
+	}
+
+	out := make(Metadata, metadataSize)
+	for k, v := range raw.md {
+		out[k] = copyOf(v)
+	}
+	for _, added := range raw.added {
+		if len(added)%2 == 1 {
+			panic(fmt.Sprintf("metadata: FromOutgoingContext got an odd number of input pairs for metadata: %d", len(added)))
+		}
+
+		for i := 0; i < len(added); i += 2 {
+			out[added[i]] = append(out[added[i]], added[i+1])
+		}
+	}
+	return out, ok
+}
+
+type rawMetadata struct {
+	md    Metadata
+	added [][]string
+}
+
 // Iterator used to iterate over metadata with order
 type Iterator struct {
 	md   Metadata
@@ -47,14 +466,18 @@ type Iterator struct {
 }
 
 // Next advance iterator to next element
-func (iter *Iterator) Next(k, v *string) bool {
+func (iter *Iterator) Next(k *string, v *[]string) bool {
 	if iter.cur+1 > iter.cnt {
 		return false
 	}
 
-	*k = iter.keys[iter.cur]
-	*v = iter.md[*k]
-	iter.cur++
+	if k != nil && v != nil {
+		*k = iter.keys[iter.cur]
+		vv := iter.md[*k]
+		*v = make([]string, len(vv))
+		copy(*v, vv)
+		iter.cur++
+	}
 	return true
 }
 
@@ -68,102 +491,3 @@ func (md Metadata) Iterator() *Iterator {
 	sort.Strings(iter.keys)
 	return iter
 }
-
-func (md Metadata) MustGet(key string) string {
-	val, ok := md.Get(key)
-	if !ok {
-		panic("missing metadata key")
-	}
-	return val
-}
-
-// Get returns value from metadata by key
-func (md Metadata) Get(key string) (string, bool) {
-	// fast path
-	val, ok := md[key]
-	if !ok {
-		// slow path
-		val, ok = md[textproto.CanonicalMIMEHeaderKey(key)]
-		if !ok {
-			val, ok = md[strings.ToLower(key)]
-		}
-	}
-	return val, ok
-}
-
-// Set is used to store value in metadata
-func (md Metadata) Set(kv ...string) {
-	if len(kv)%2 == 1 {
-		kv = kv[:len(kv)-1]
-	}
-	for idx := 0; idx < len(kv); idx += 2 {
-		md[textproto.CanonicalMIMEHeaderKey(kv[idx])] = kv[idx+1]
-	}
-}
-
-// Del is used to remove value from metadata
-func (md Metadata) Del(keys ...string) {
-	for _, key := range keys {
-		// fast path
-		delete(md, key)
-		// slow path
-		delete(md, textproto.CanonicalMIMEHeaderKey(key))
-		// very slow path
-		delete(md, strings.ToLower(key))
-	}
-}
-
-// Copy makes a copy of the metadata
-func (md Metadata) CopyTo(dst Metadata) {
-	for k, v := range md {
-		dst[k] = v
-	}
-}
-
-// Copy makes a copy of the metadata
-func Copy(md Metadata, exclude ...string) Metadata {
-	nmd := New(len(md))
-	for k, v := range md {
-		nmd[k] = v
-	}
-	nmd.Del(exclude...)
-	return nmd
-}
-
-// New return new sized metadata
-func New(size int) Metadata {
-	if size == 0 {
-		size = defaultMetadataSize
-	}
-	return make(Metadata, size)
-}
-
-// Merge merges metadata to existing metadata, overwriting if specified
-func Merge(omd Metadata, mmd Metadata, overwrite bool) Metadata {
-	var ok bool
-	nmd := Copy(omd)
-	for key, val := range mmd {
-		_, ok = nmd[key]
-		switch {
-		case ok && !overwrite:
-			continue
-		case val != "":
-			nmd[key] = val
-		case ok && val == "":
-			nmd.Del(key)
-		}
-	}
-	return nmd
-}
-
-// Pairs from which metadata created
-func Pairs(kv ...string) (Metadata, bool) {
-	if len(kv)%2 == 1 {
-		return nil, false
-	}
-	md := New(len(kv) / 2)
-	for idx := 0; idx < len(kv); idx += 2 {
-		md[kv[idx]] = kv[idx+1]
-	}
-	return md, true
-}
diff --git a/metadata/metadata_grpc.go b/metadata/metadata_grpc.go
deleted file mode 100644
index f5f2bbf1..00000000
--- a/metadata/metadata_grpc.go
+++ /dev/null
@@ -1,282 +0,0 @@
-//go:build exclude
-
-// Package metadata TODO need compare with micro metadata
-package metadata // import "google.golang.org/grpc/metadata"
-
-import (
-	"context"
-	"fmt"
-	"strings"
-)
-
-// MD is a mapping from metadata keys to values. Users should use the following
-// two convenience functions New and Pairs to generate MD.
-type MD map[string][]string
-
-type Metadata map[string]string
-
-// New creates an MD from a given key-value map.
-//
-// Only the following ASCII characters are allowed in keys:
-//   - digits: 0-9
-//   - uppercase letters: A-Z (normalized to lower)
-//   - lowercase letters: a-z
-//   - special characters: -_.
-//
-// Uppercase letters are automatically converted to lowercase.
-//
-// Keys beginning with "grpc-" are reserved for grpc-internal use only and may
-// result in errors if set in metadata.
-func New(m map[string]string) MD {
-	md := make(MD, len(m))
-	for k, val := range m {
-		key := strings.ToLower(k)
-		md[key] = append(md[key], val)
-	}
-	return md
-}
-
-// Pairs returns an MD formed by the mapping of key, value ...
-// Pairs panics if len(kv) is odd.
-//
-// Only the following ASCII characters are allowed in keys:
-//   - digits: 0-9
-//   - uppercase letters: A-Z (normalized to lower)
-//   - lowercase letters: a-z
-//   - special characters: -_.
-//
-// Uppercase letters are automatically converted to lowercase.
-//
-// Keys beginning with "grpc-" are reserved for grpc-internal use only and may
-// result in errors if set in metadata.
-func Pairs(kv ...string) MD {
-	if len(kv)%2 == 1 {
-		panic(fmt.Sprintf("metadata: Pairs got the odd number of input pairs for metadata: %d", len(kv)))
-	}
-	md := make(MD, len(kv)/2)
-	for i := 0; i < len(kv); i += 2 {
-		key := strings.ToLower(kv[i])
-		md[key] = append(md[key], kv[i+1])
-	}
-	return md
-}
-
-// Len returns the number of items in md.
-func (md MD) Len() int {
-	return len(md)
-}
-
-// Copy returns a copy of md.
-func (md MD) Copy() MD {
-	out := make(MD, len(md))
-	for k, v := range md {
-		out[k] = copyOf(v)
-	}
-	return out
-}
-
-// Get obtains the values for a given key.
-//
-// k is converted to lowercase before searching in md.
-func (md MD) Get(k string) []string {
-	k = strings.ToLower(k)
-	return md[k]
-}
-
-// Set sets the value of a given key with a slice of values.
-//
-// k is converted to lowercase before storing in md.
-func (md MD) Set(k string, vals ...string) {
-	if len(vals) == 0 {
-		return
-	}
-	k = strings.ToLower(k)
-	md[k] = vals
-}
-
-// Append adds the values to key k, not overwriting what was already stored at
-// that key.
-//
-// k is converted to lowercase before storing in md.
-func (md MD) Append(k string, vals ...string) {
-	if len(vals) == 0 {
-		return
-	}
-	k = strings.ToLower(k)
-	md[k] = append(md[k], vals...)
-}
-
-// Delete removes the values for a given key k which is converted to lowercase
-// before removing it from md.
-func (md MD) Delete(k string) {
-	k = strings.ToLower(k)
-	delete(md, k)
-}
-
-// Join joins any number of mds into a single MD.
-//
-// The order of values for each key is determined by the order in which the mds
-// containing those values are presented to Join.
-func Join(mds ...MD) MD {
-	out := MD{}
-	for _, md := range mds {
-		for k, v := range md {
-			out[k] = append(out[k], v...)
-		}
-	}
-	return out
-}
-
-type mdIncomingKey struct{}
-type mdOutgoingKey struct{}
-
-// NewIncomingContext creates a new context with incoming md attached. md must
-// not be modified after calling this function.
-func NewIncomingContext(ctx context.Context, md Metadata) context.Context {
-	in := make(MD, len(md))
-	for k, v := range md {
-		in[k] = []string{v}
-	}
-
-	return context.WithValue(ctx, mdIncomingKey{}, in)
-}
-
-// NewOutgoingContext creates a new context with outgoing md attached. If used
-// in conjunction with AppendToOutgoingContext, NewOutgoingContext will
-// overwrite any previously-appended metadata. md must not be modified after
-// calling this function.
-func NewOutgoingContext(ctx context.Context, md Metadata) context.Context {
-	out := make(MD, len(md))
-	for k, v := range md {
-		out[k] = []string{v}
-	}
-
-	return context.WithValue(ctx, mdOutgoingKey{}, rawMD{md: out})
-}
-
-// AppendToOutgoingContext returns a new context with the provided kv merged
-// with any existing metadata in the context. Please refer to the documentation
-// of Pairs for a description of kv.
-func AppendToOutgoingContext(ctx context.Context, kv ...string) context.Context {
-	if len(kv)%2 == 1 {
-		panic(fmt.Sprintf("metadata: AppendToOutgoingContext got an odd number of input pairs for metadata: %d", len(kv)))
-	}
-	md, _ := ctx.Value(mdOutgoingKey{}).(rawMD)
-	added := make([][]string, len(md.added)+1)
-	copy(added, md.added)
-	kvCopy := make([]string, 0, len(kv))
-	for i := 0; i < len(kv); i += 2 {
-		kvCopy = append(kvCopy, strings.ToLower(kv[i]), kv[i+1])
-	}
-	added[len(added)-1] = kvCopy
-	return context.WithValue(ctx, mdOutgoingKey{}, rawMD{md: md.md, added: added})
-}
-
-// FromIncomingContext returns the incoming metadata in ctx if it exists.
-//
-// All keys in the returned MD are lowercase.
-func FromIncomingContext(ctx context.Context) (Metadata, bool) {
-	md, ok := ctx.Value(mdIncomingKey{}).(MD)
-	if !ok {
-		return nil, false
-	}
-	out := make(Metadata, len(md))
-	for k, v := range md {
-		// We need to manually convert all keys to lower case, because MD is a
-		// map, and there's no guarantee that the MD attached to the context is
-		// created using our helper functions.
-
-		if len(v) > 0 {
-			key := strings.ToLower(k)
-			out[key] = v[0]
-		}
-
-	}
-	return out, true
-}
-
-// ValueFromIncomingContext returns the metadata value corresponding to the metadata
-// key from the incoming metadata if it exists. Keys are matched in a case insensitive
-// manner.
-func ValueFromIncomingContext(ctx context.Context, key string) []string {
-	md, ok := ctx.Value(mdIncomingKey{}).(MD)
-	if !ok {
-		return nil
-	}
-
-	if v, ok := md[key]; ok {
-		return copyOf(v)
-	}
-	for k, v := range md {
-		// Case insensitive comparison: MD is a map, and there's no guarantee
-		// that the MD attached to the context is created using our helper
-		// functions.
-		if strings.EqualFold(k, key) {
-			return copyOf(v)
-		}
-	}
-	return nil
-}
-
-func copyOf(v []string) []string {
-	vals := make([]string, len(v))
-	copy(vals, v)
-	return vals
-}
-
-// fromOutgoingContextRaw returns the un-merged, intermediary contents of rawMD.
-//
-// Remember to perform strings.ToLower on the keys, for both the returned MD (MD
-// is a map, there's no guarantee it's created using our helper functions) and
-// the extra kv pairs (AppendToOutgoingContext doesn't turn them into
-// lowercase).
-func fromOutgoingContextRaw(ctx context.Context) (MD, [][]string, bool) {
-	raw, ok := ctx.Value(mdOutgoingKey{}).(rawMD)
-	if !ok {
-		return nil, nil, false
-	}
-
-	return raw.md, raw.added, true
-}
-
-// FromOutgoingContext returns the outgoing metadata in ctx if it exists.
-//
-// All keys in the returned MD are lowercase.
-func FromOutgoingContext(ctx context.Context) (Metadata, bool) {
-	raw, ok := ctx.Value(mdOutgoingKey{}).(rawMD)
-	if !ok {
-		return nil, false
-	}
-
-	mdSize := len(raw.md)
-	for i := range raw.added {
-		mdSize += len(raw.added[i]) / 2
-	}
-
-	out := make(Metadata, mdSize)
-	for k, v := range raw.md {
-		// We need to manually convert all keys to lower case, because MD is a
-		// map, and there's no guarantee that the MD attached to the context is
-		// created using our helper functions.
-		if len(v) > 0 {
-			key := strings.ToLower(k)
-			out[key] = v[0]
-		}
-	}
-	for _, added := range raw.added {
-		if len(added)%2 == 1 {
-			panic(fmt.Sprintf("metadata: FromOutgoingContext got an odd number of input pairs for metadata: %d", len(added)))
-		}
-
-		for i := 0; i < len(added); i += 2 {
-			key := strings.ToLower(added[i])
-			out[key] = added[i+1]
-		}
-	}
-	return out, ok
-}
-
-type rawMD struct {
-	md    MD
-	added [][]string
-}
diff --git a/metadata/metadata_test.go b/metadata/metadata_test.go
index 47d53cf9..4b1a47c7 100644
--- a/metadata/metadata_test.go
+++ b/metadata/metadata_test.go
@@ -5,10 +5,21 @@ import (
 	"testing"
 )
 
+/*
+func TestAppendOutgoingContextModify(t *testing.T) {
+	md := Pairs("key1", "val1")
+	ctx := NewOutgoingContext(context.TODO(), md)
+	nctx := AppendOutgoingContext(ctx, "key1", "val3", "key2", "val2")
+	_ = nctx
+	omd := MustOutgoingContext(nctx)
+	fmt.Printf("%#+v\n", omd)
+}
+*/
+
 func TestLowercase(t *testing.T) {
 	md := New(1)
-	md["x-request-id"] = "12345"
-	v, ok := md.Get("X-Request-Id")
+	md["x-request-id"] = []string{"12345"}
+	v, ok := md.GetJoined("X-Request-Id")
 	if !ok || v == "" {
 		t.Fatalf("metadata invalid %#+v", md)
 	}
@@ -38,15 +49,12 @@ func TestMultipleUsage(t *testing.T) {
 
 func TestMetadataSetMultiple(t *testing.T) {
 	md := New(4)
-	md.Set("key1", "val1", "key2", "val2", "key3")
+	md.Set("key1", "val1", "key2", "val2")
 
-	if v, ok := md.Get("key1"); !ok || v != "val1" {
+	if v, ok := md.GetJoined("key1"); !ok || v != "val1" {
 		t.Fatalf("invalid kv %#+v", md)
 	}
-	if v, ok := md.Get("key2"); !ok || v != "val2" {
-		t.Fatalf("invalid kv %#+v", md)
-	}
-	if _, ok := md.Get("key3"); ok {
+	if v, ok := md.GetJoined("key2"); !ok || v != "val2" {
 		t.Fatalf("invalid kv %#+v", md)
 	}
 }
@@ -64,22 +72,12 @@ func TestAppend(t *testing.T) {
 }
 
 func TestPairs(t *testing.T) {
-	md, ok := Pairs("key1", "val1", "key2", "val2")
-	if !ok {
-		t.Fatal("odd number of kv")
-	}
-	if _, ok = md.Get("key1"); !ok {
+	md := Pairs("key1", "val1", "key2", "val2")
+	if _, ok := md.Get("key1"); !ok {
 		t.Fatal("key1 not found")
 	}
 }
 
-func testCtx(ctx context.Context) {
-	md := New(2)
-	md.Set("Key1", "Val1_new")
-	md.Set("Key3", "Val3")
-	SetOutgoingContext(ctx, md)
-}
-
 func TestPassing(t *testing.T) {
 	ctx := context.TODO()
 	md1 := New(2)
@@ -87,69 +85,62 @@ func TestPassing(t *testing.T) {
 	md1.Set("Key2", "Val2")
 
 	ctx = NewIncomingContext(ctx, md1)
-	testCtx(ctx)
+
 	_, ok := FromOutgoingContext(ctx)
 	if ok {
 		t.Fatalf("create outgoing context")
 	}
 
-	ctx = NewOutgoingContext(ctx, New(1))
-	testCtx(ctx)
+	ctx = NewOutgoingContext(ctx, md1)
+
 	md, ok := FromOutgoingContext(ctx)
 	if !ok {
 		t.Fatalf("missing metadata from outgoing context")
 	}
-	if v, ok := md.Get("Key1"); !ok || v != "Val1_new" {
+	if v, ok := md.Get("Key1"); !ok || v[0] != "Val1" {
 		t.Fatalf("invalid metadata value %#+v", md)
 	}
 }
 
-func TestMerge(t *testing.T) {
-	omd := Metadata{
-		"key1": "val1",
-	}
-	mmd := Metadata{
-		"key2": "val2",
-	}
-
-	nmd := Merge(omd, mmd, true)
-	if len(nmd) != 2 {
-		t.Fatalf("merge failed: %v", nmd)
-	}
-}
-
-func TestIterator(_ *testing.T) {
-	md := Metadata{
-		"1Last":   "last",
-		"2First":  "first",
-		"3Second": "second",
-	}
+func TestIterator(t *testing.T) {
+	md := Pairs(
+		"1Last", "last",
+		"2First", "first",
+		"3Second", "second",
+	)
 
 	iter := md.Iterator()
-	var k, v string
-
+	var k string
+	var v []string
+	chk := New(3)
 	for iter.Next(&k, &v) {
-		// fmt.Printf("k: %s, v: %s\n", k, v)
+		chk[k] = v
+	}
+
+	for k, v := range chk {
+		if cv, ok := md[k]; !ok || len(cv) != len(v) || cv[0] != v[0] {
+			t.Fatalf("XXXX %#+v %#+v", chk, md)
+		}
 	}
 }
 
 func TestMedataCanonicalKey(t *testing.T) {
 	md := New(1)
 	md.Set("x-request-id", "12345")
-	v, ok := md.Get("x-request-id")
+	v, ok := md.GetJoined("x-request-id")
 	if !ok {
 		t.Fatalf("failed to get x-request-id")
 	} else if v != "12345" {
 		t.Fatalf("invalid metadata value: %s != %s", "12345", v)
 	}
 
-	v, ok = md.Get("X-Request-Id")
+	v, ok = md.GetJoined("X-Request-Id")
 	if !ok {
 		t.Fatalf("failed to get x-request-id")
 	} else if v != "12345" {
 		t.Fatalf("invalid metadata value: %s != %s", "12345", v)
 	}
-	v, ok = md.Get("X-Request-ID")
+	v, ok = md.GetJoined("X-Request-ID")
 	if !ok {
 		t.Fatalf("failed to get x-request-id")
 	} else if v != "12345" {
@@ -162,7 +153,7 @@ func TestMetadataSet(t *testing.T) {
 
 	md.Set("Key", "val")
 
-	val, ok := md.Get("Key")
+	val, ok := md.GetJoined("Key")
 	if !ok {
 		t.Fatal("key Key not found")
 	}
@@ -173,8 +164,8 @@ func TestMetadataSet(t *testing.T) {
 
 func TestMetadataDelete(t *testing.T) {
 	md := Metadata{
-		"Foo": "bar",
-		"Baz": "empty",
+		"Foo": []string{"bar"},
+		"Baz": []string{"empty"},
 	}
 
 	md.Del("Baz")
@@ -184,25 +175,16 @@ func TestMetadataDelete(t *testing.T) {
 	}
 }
 
-func TestNilContext(t *testing.T) {
-	var ctx context.Context
-
-	_, ok := FromContext(ctx)
-	if ok {
-		t.Fatal("nil context")
-	}
-}
-
 func TestMetadataCopy(t *testing.T) {
 	md := Metadata{
-		"Foo": "bar",
-		"Bar": "baz",
+		"Foo": []string{"bar"},
+		"Bar": []string{"baz"},
 	}
 
 	cp := Copy(md)
 
 	for k, v := range md {
-		if cv := cp[k]; cv != v {
+		if cv := cp[k]; cv[0] != v[0] {
 			t.Fatalf("Got %s:%s for %s:%s", k, cv, k, v)
 		}
 	}
@@ -210,7 +192,7 @@ func TestMetadataCopy(t *testing.T) {
 
 func TestMetadataContext(t *testing.T) {
 	md := Metadata{
-		"Foo": "bar",
+		"Foo": []string{"bar"},
 	}
 
 	ctx := NewContext(context.TODO(), md)
@@ -220,7 +202,7 @@ func TestMetadataContext(t *testing.T) {
 		t.Errorf("Unexpected error retrieving metadata, got %t", ok)
 	}
 
-	if emd["Foo"] != md["Foo"] {
+	if emd["Foo"][0] != md["Foo"][0] {
 		t.Errorf("Expected key: %s val: %s, got key: %s val: %s", "Foo", md["Foo"], "Foo", emd["Foo"])
 	}
 
@@ -229,13 +211,88 @@ func TestMetadataContext(t *testing.T) {
 	}
 }
 
-func TestCopy(t *testing.T) {
-	md := New(2)
-	md.Set("key1", "val1", "key2", "val2")
-	nmd := Copy(md, "key2")
-	if len(nmd) != 1 {
-		t.Fatal("Copy exclude not works")
-	} else if nmd["Key1"] != "val1" {
-		t.Fatal("Copy exclude not works")
+func TestFromContext(t *testing.T) {
+	ctx := context.WithValue(context.TODO(), metadataCurrentKey{}, rawMetadata{md: New(0)})
+
+	c, ok := FromContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("FromContext not works")
+	}
+}
+
+func TestNewContext(t *testing.T) {
+	ctx := NewContext(context.TODO(), New(0))
+
+	c, ok := FromContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("NewContext not works")
+	}
+}
+
+func TestFromIncomingContext(t *testing.T) {
+	ctx := context.WithValue(context.TODO(), metadataIncomingKey{}, rawMetadata{md: New(0)})
+
+	c, ok := FromIncomingContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("FromIncomingContext not works")
+	}
+}
+
+func TestFromOutgoingContext(t *testing.T) {
+	ctx := context.WithValue(context.TODO(), metadataOutgoingKey{}, rawMetadata{md: New(0)})
+
+	c, ok := FromOutgoingContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("FromOutgoingContext not works")
+	}
+}
+
+func TestNewIncomingContext(t *testing.T) {
+	md := New(1)
+	md.Set("key", "val")
+	ctx := NewIncomingContext(context.TODO(), md)
+
+	c, ok := FromIncomingContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("NewIncomingContext not works")
+	}
+}
+
+func TestNewOutgoingContext(t *testing.T) {
+	md := New(1)
+	md.Set("key", "val")
+	ctx := NewOutgoingContext(context.TODO(), md)
+
+	c, ok := FromOutgoingContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("NewOutgoingContext not works")
+	}
+}
+
+func TestAppendIncomingContext(t *testing.T) {
+	md := New(1)
+	md.Set("key1", "val1")
+	ctx := AppendIncomingContext(context.TODO(), "key2", "val2")
+
+	nmd, ok := FromIncomingContext(ctx)
+	if nmd == nil || !ok {
+		t.Fatal("AppendIncomingContext not works")
+	}
+	if v, ok := nmd.GetJoined("key2"); !ok || v != "val2" {
+		t.Fatal("AppendIncomingContext not works")
+	}
+}
+
+func TestAppendOutgoingContext(t *testing.T) {
+	md := New(1)
+	md.Set("key1", "val1")
+	ctx := AppendOutgoingContext(context.TODO(), "key2", "val2")
+
+	nmd, ok := FromOutgoingContext(ctx)
+	if nmd == nil || !ok {
+		t.Fatal("AppendOutgoingContext not works")
+	}
+	if v, ok := nmd.GetJoined("key2"); !ok || v != "val2" {
+		t.Fatal("AppendOutgoingContext not works")
 	}
 }
diff --git a/micro_test.go b/micro_test.go
index f92c223e..f8990f6f 100644
--- a/micro_test.go
+++ b/micro_test.go
@@ -8,6 +8,7 @@ import (
 
 	"go.unistack.org/micro/v4/broker"
 	"go.unistack.org/micro/v4/fsm"
+	"go.unistack.org/micro/v4/metadata"
 )
 
 func TestAs(t *testing.T) {
@@ -61,6 +62,8 @@ func TestAs(t *testing.T) {
 	}
 }
 
+var _ broker.Broker = (*bro)(nil)
+
 type bro struct {
 	name string
 }
@@ -87,23 +90,18 @@ func (p *bro) Connect(_ context.Context) error { return nil }
 // Disconnect disconnect from broker
 func (p *bro) Disconnect(_ context.Context) error { return nil }
 
-// Publish message, msg can be single broker.Message or []broker.Message
-func (p *bro) Publish(_ context.Context, _ string, _ *broker.Message, _ ...broker.PublishOption) error {
-	return nil
-}
-
-// BatchPublish messages to broker with multiple topics
-func (p *bro) BatchPublish(_ context.Context, _ []*broker.Message, _ ...broker.PublishOption) error {
-	return nil
-}
-
-// BatchSubscribe subscribes to topic messages via handler
-func (p *bro) BatchSubscribe(_ context.Context, _ string, _ broker.BatchHandler, _ ...broker.SubscribeOption) (broker.Subscriber, error) {
+// NewMessage creates new message
+func (p *bro) NewMessage(_ context.Context, _ metadata.Metadata, _ interface{}, _ ...broker.PublishOption) (broker.Message, error) {
 	return nil, nil
 }
 
+// Publish message, msg can be single broker.Message or []broker.Message
+func (p *bro) Publish(_ context.Context, _ string, _ ...broker.Message) error {
+	return nil
+}
+
 // Subscribe subscribes to topic message via handler
-func (p *bro) Subscribe(_ context.Context, _ string, _ broker.Handler, _ ...broker.SubscribeOption) (broker.Subscriber, error) {
+func (p *bro) Subscribe(_ context.Context, _ string, _ interface{}, _ ...broker.SubscribeOption) (broker.Subscriber, error) {
 	return nil, nil
 }
 
diff --git a/network/network.go b/network/network.go
deleted file mode 100644
index 125f3a92..00000000
--- a/network/network.go
+++ /dev/null
@@ -1,55 +0,0 @@
-// Package network is for creating internetworks
-package network
-
-import (
-	"go.unistack.org/micro/v4/client"
-	"go.unistack.org/micro/v4/server"
-)
-
-// Error is network node errors
-type Error interface {
-	// Count is current count of errors
-	Count() int
-	// Msg is last error message
-	Msg() string
-}
-
-// Status is node status
-type Status interface {
-	// Error reports error status
-	Error() Error
-}
-
-// Node is network node
-type Node interface {
-	// Id is node id
-	Id() string
-	// Address is node bind address
-	Address() string
-	// Peers returns node peers
-	Peers() []Node
-	// Network is the network node is in
-	Network() Network
-	// Status returns node status
-	Status() Status
-}
-
-// Network is micro network
-type Network interface {
-	// Node is network node
-	Node
-	// Initialise options
-	Init(...Option) error
-	// Options returns the network options
-	Options() Options
-	// Name of the network
-	Name() string
-	// Connect starts the resolver and tunnel server
-	Connect() error
-	// Close stops the tunnel and resolving
-	Close() error
-	// Client is micro client
-	Client() client.Client
-	// Server is micro server
-	Server() server.Server
-}
diff --git a/network/options.go b/network/options.go
deleted file mode 100644
index 1bf2fdaa..00000000
--- a/network/options.go
+++ /dev/null
@@ -1,135 +0,0 @@
-package network
-
-import (
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v4/network/tunnel"
-	"go.unistack.org/micro/v4/proxy"
-	"go.unistack.org/micro/v4/router"
-	"go.unistack.org/micro/v4/tracer"
-	"go.unistack.org/micro/v4/util/id"
-)
-
-// Option func
-type Option func(*Options)
-
-// Options configure network
-type Options struct {
-	// Router used for routing
-	Router router.Router
-	// Proxy holds the proxy
-	Proxy proxy.Proxy
-	// Logger used for logging
-	Logger logger.Logger
-	// Meter used for metrics
-	Meter meter.Meter
-	// Tracer used for tracing
-	Tracer tracer.Tracer
-	// Tunnel used for transfer data
-	Tunnel tunnel.Tunnel
-	// ID of the node
-	ID string
-	// Name of the network
-	Name string
-	// Address to bind to
-	Address string
-	// Advertise sets the address to advertise
-	Advertise string
-	// Nodes is a list of nodes to connect to
-	Nodes []string
-}
-
-// ID sets the id of the network node
-func ID(id string) Option {
-	return func(o *Options) {
-		o.ID = id
-	}
-}
-
-// Name sets the network name
-func Name(n string) Option {
-	return func(o *Options) {
-		o.Name = n
-	}
-}
-
-// Address sets the network address
-func Address(a string) Option {
-	return func(o *Options) {
-		o.Address = a
-	}
-}
-
-// Advertise sets the address to advertise
-func Advertise(a string) Option {
-	return func(o *Options) {
-		o.Advertise = a
-	}
-}
-
-// Nodes is a list of nodes to connect to
-func Nodes(n ...string) Option {
-	return func(o *Options) {
-		o.Nodes = n
-	}
-}
-
-// Tunnel sets the network tunnel
-func Tunnel(t tunnel.Tunnel) Option {
-	return func(o *Options) {
-		o.Tunnel = t
-	}
-}
-
-// Router sets the network router
-func Router(r router.Router) Option {
-	return func(o *Options) {
-		o.Router = r
-	}
-}
-
-// Proxy sets the network proxy
-func Proxy(p proxy.Proxy) Option {
-	return func(o *Options) {
-		o.Proxy = p
-	}
-}
-
-// Logger sets the network logger
-func Logger(l logger.Logger) Option {
-	return func(o *Options) {
-		o.Logger = l
-	}
-}
-
-// Meter sets the meter
-func Meter(m meter.Meter) Option {
-	return func(o *Options) {
-		o.Meter = m
-	}
-}
-
-// Tracer to be used for tracing
-func Tracer(t tracer.Tracer) Option {
-	return func(o *Options) {
-		o.Tracer = t
-	}
-}
-
-// NewOptions returns network default options
-func NewOptions(opts ...Option) Options {
-	options := Options{
-		ID:      id.MustNew(),
-		Name:    "go.micro",
-		Address: ":0",
-		Logger:  logger.DefaultLogger,
-		Meter:   meter.DefaultMeter,
-		Tracer:  tracer.DefaultTracer,
-	}
-
-	for _, o := range opts {
-		o(&options)
-	}
-
-	return options
-}
diff --git a/network/transport/context.go b/network/transport/context.go
deleted file mode 100644
index 73e4681d..00000000
--- a/network/transport/context.go
+++ /dev/null
@@ -1,34 +0,0 @@
-package transport
-
-import (
-	"context"
-)
-
-type transportKey struct{}
-
-// FromContext get transport from context
-func FromContext(ctx context.Context) (Transport, bool) {
-	if ctx == nil {
-		return nil, false
-	}
-	c, ok := ctx.Value(transportKey{}).(Transport)
-	return c, ok
-}
-
-// NewContext put transport in context
-func NewContext(ctx context.Context, c Transport) context.Context {
-	if ctx == nil {
-		ctx = context.Background()
-	}
-	return context.WithValue(ctx, transportKey{}, c)
-}
-
-// SetOption returns a function to setup a context with given value
-func SetOption(k, v interface{}) Option {
-	return func(o *Options) {
-		if o.Context == nil {
-			o.Context = context.Background()
-		}
-		o.Context = context.WithValue(o.Context, k, v)
-	}
-}
diff --git a/network/transport/memory.go b/network/transport/memory.go
deleted file mode 100644
index 6447978f..00000000
--- a/network/transport/memory.go
+++ /dev/null
@@ -1,258 +0,0 @@
-package transport
-
-import (
-	"context"
-	"errors"
-	"fmt"
-	"net"
-	"sync"
-	"time"
-
-	maddr "go.unistack.org/micro/v4/util/addr"
-	mnet "go.unistack.org/micro/v4/util/net"
-	"go.unistack.org/micro/v4/util/rand"
-)
-
-type memorySocket struct {
-	ctx     context.Context
-	recv    chan *Message
-	exit    chan bool
-	lexit   chan bool
-	send    chan *Message
-	local   string
-	remote  string
-	timeout time.Duration
-	sync.RWMutex
-}
-
-type memoryClient struct {
-	*memorySocket
-	opts DialOptions
-}
-
-type memoryListener struct {
-	lopts ListenOptions
-	ctx   context.Context
-	exit  chan bool
-	conn  chan *memorySocket
-	addr  string
-	topts Options
-	sync.RWMutex
-}
-
-type memoryTransport struct {
-	listeners map[string]*memoryListener
-	opts      Options
-	sync.RWMutex
-}
-
-func (ms *memorySocket) Recv(m *Message) error {
-	ms.RLock()
-	defer ms.RUnlock()
-
-	ctx := ms.ctx
-	if ms.timeout > 0 {
-		var cancel context.CancelFunc
-		ctx, cancel = context.WithTimeout(ms.ctx, ms.timeout)
-		defer cancel()
-	}
-
-	select {
-	case <-ctx.Done():
-		return ctx.Err()
-	case <-ms.exit:
-		return errors.New("connection closed")
-	case <-ms.lexit:
-		return errors.New("server connection closed")
-	case cm := <-ms.recv:
-		*m = *cm
-	}
-	return nil
-}
-
-func (ms *memorySocket) Local() string {
-	return ms.local
-}
-
-func (ms *memorySocket) Remote() string {
-	return ms.remote
-}
-
-func (ms *memorySocket) Send(m *Message) error {
-	ms.RLock()
-	defer ms.RUnlock()
-
-	ctx := ms.ctx
-	if ms.timeout > 0 {
-		var cancel context.CancelFunc
-		ctx, cancel = context.WithTimeout(ms.ctx, ms.timeout)
-		defer cancel()
-	}
-
-	select {
-	case <-ctx.Done():
-		return ctx.Err()
-	case <-ms.exit:
-		return errors.New("connection closed")
-	case <-ms.lexit:
-		return errors.New("server connection closed")
-	case ms.send <- m:
-	}
-	return nil
-}
-
-func (ms *memorySocket) Close() error {
-	ms.Lock()
-	defer ms.Unlock()
-	select {
-	case <-ms.exit:
-		return nil
-	default:
-		close(ms.exit)
-	}
-	return nil
-}
-
-func (m *memoryListener) Addr() string {
-	return m.addr
-}
-
-func (m *memoryListener) Close() error {
-	m.Lock()
-	defer m.Unlock()
-	select {
-	case <-m.exit:
-		return nil
-	default:
-		close(m.exit)
-	}
-	return nil
-}
-
-func (m *memoryListener) Accept(fn func(Socket)) error {
-	for {
-		select {
-		case <-m.exit:
-			return nil
-		case c := <-m.conn:
-			go fn(&memorySocket{
-				lexit:   c.lexit,
-				exit:    c.exit,
-				send:    c.recv,
-				recv:    c.send,
-				local:   c.Remote(),
-				remote:  c.Local(),
-				timeout: m.topts.Timeout,
-				ctx:     m.topts.Context,
-			})
-		}
-	}
-}
-
-func (m *memoryTransport) Dial(ctx context.Context, addr string, opts ...DialOption) (Client, error) {
-	m.RLock()
-	defer m.RUnlock()
-
-	listener, ok := m.listeners[addr]
-	if !ok {
-		return nil, errors.New("could not dial " + addr)
-	}
-
-	options := NewDialOptions(opts...)
-
-	client := &memoryClient{
-		&memorySocket{
-			send:    make(chan *Message),
-			recv:    make(chan *Message),
-			exit:    make(chan bool),
-			lexit:   listener.exit,
-			local:   addr,
-			remote:  addr,
-			timeout: m.opts.Timeout,
-			ctx:     m.opts.Context,
-		},
-		options,
-	}
-
-	// pseudo connect
-	select {
-	case <-listener.exit:
-		return nil, errors.New("connection error")
-	case listener.conn <- client.memorySocket:
-	}
-
-	return client, nil
-}
-
-func (m *memoryTransport) Listen(ctx context.Context, addr string, opts ...ListenOption) (Listener, error) {
-	m.Lock()
-	defer m.Unlock()
-
-	options := NewListenOptions(opts...)
-
-	host, port, err := net.SplitHostPort(addr)
-	if err != nil {
-		return nil, err
-	}
-
-	addr, err = maddr.Extract(host)
-	if err != nil {
-		return nil, err
-	}
-
-	// if zero port then randomly assign one
-	if len(port) > 0 && port == "0" {
-		var rng rand.Rand
-		i := rng.Intn(20000)
-		port = fmt.Sprintf("%d", 10000+i)
-	}
-
-	// set addr with port
-	addr = mnet.HostPort(addr, port)
-
-	if _, ok := m.listeners[addr]; ok {
-		return nil, errors.New("already listening on " + addr)
-	}
-
-	listener := &memoryListener{
-		lopts: options,
-		topts: m.opts,
-		addr:  addr,
-		conn:  make(chan *memorySocket),
-		exit:  make(chan bool),
-		ctx:   m.opts.Context,
-	}
-
-	m.listeners[addr] = listener
-
-	return listener, nil
-}
-
-func (m *memoryTransport) Init(opts ...Option) error {
-	for _, o := range opts {
-		o(&m.opts)
-	}
-	return nil
-}
-
-func (m *memoryTransport) Options() Options {
-	return m.opts
-}
-
-func (m *memoryTransport) String() string {
-	return "memory"
-}
-
-func (m *memoryTransport) Name() string {
-	return m.opts.Name
-}
-
-// NewTransport returns new memory transport with options
-func NewTransport(opts ...Option) Transport {
-	options := NewOptions(opts...)
-
-	return &memoryTransport{
-		opts:      options,
-		listeners: make(map[string]*memoryListener),
-	}
-}
diff --git a/network/transport/memory_test.go b/network/transport/memory_test.go
deleted file mode 100644
index cf712b86..00000000
--- a/network/transport/memory_test.go
+++ /dev/null
@@ -1,100 +0,0 @@
-package transport
-
-import (
-	"context"
-	"os"
-	"testing"
-)
-
-func TestMemoryTransport(t *testing.T) {
-	tr := NewTransport()
-	ctx := context.Background()
-	// bind / listen
-	l, err := tr.Listen(ctx, "127.0.0.1:8080")
-	if err != nil {
-		t.Fatalf("Unexpected error listening %v", err)
-	}
-	defer l.Close()
-
-	cherr := make(chan error, 1)
-	// accept
-	go func() {
-		if nerr := l.Accept(func(sock Socket) {
-			for {
-				var m Message
-				if rerr := sock.Recv(&m); rerr != nil {
-					cherr <- rerr
-					return
-				}
-				if len(os.Getenv("INTEGRATION_TESTS")) == 0 {
-					t.Logf("Server Received %s", string(m.Body))
-				}
-				if cerr := sock.Send(&Message{
-					Body: []byte(`pong`),
-				}); cerr != nil {
-					cherr <- cerr
-					return
-				}
-			}
-		}); nerr != nil {
-			cherr <- err
-		}
-	}()
-
-	// dial
-	c, err := tr.Dial(ctx, "127.0.0.1:8080")
-	if err != nil {
-		t.Fatalf("Unexpected error dialing %v", err)
-	}
-	defer c.Close()
-
-	select {
-	case err := <-cherr:
-		t.Fatal(err)
-	default:
-		// send <=> receive
-		for i := 0; i < 3; i++ {
-			if err := c.Send(&Message{
-				Body: []byte(`ping`),
-			}); err != nil {
-				return
-			}
-			var m Message
-			if err := c.Recv(&m); err != nil {
-				return
-			}
-			if len(os.Getenv("INTEGRATION_TESTS")) == 0 {
-				t.Logf("Client Received %s", string(m.Body))
-			}
-		}
-	}
-}
-
-func TestListener(t *testing.T) {
-	tr := NewTransport()
-	ctx := context.Background()
-	// bind / listen on random port
-	l, err := tr.Listen(ctx, ":0")
-	if err != nil {
-		t.Fatalf("Unexpected error listening %v", err)
-	}
-	defer l.Close()
-
-	// try again
-	l2, err := tr.Listen(ctx, ":0")
-	if err != nil {
-		t.Fatalf("Unexpected error listening %v", err)
-	}
-	defer l2.Close()
-
-	// now make sure it still fails
-	l3, err := tr.Listen(ctx, ":8080")
-	if err != nil {
-		t.Fatalf("Unexpected error listening %v", err)
-	}
-	defer l3.Close()
-
-	if _, err := tr.Listen(ctx, ":8080"); err == nil {
-		t.Fatal("Expected error binding to :8080 got nil")
-	}
-}
diff --git a/network/transport/options.go b/network/transport/options.go
deleted file mode 100644
index 6ab32d4b..00000000
--- a/network/transport/options.go
+++ /dev/null
@@ -1,175 +0,0 @@
-package transport
-
-import (
-	"context"
-	"crypto/tls"
-	"time"
-
-	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v4/tracer"
-)
-
-// Options struct holds the transport options
-type Options struct {
-	// Meter used for metrics
-	Meter meter.Meter
-	// Tracer used for tracing
-	Tracer tracer.Tracer
-	// Codec used for marshal/unmarshal messages
-	Codec codec.Codec
-	// Logger used for logging
-	Logger logger.Logger
-	// Context holds external options
-	Context context.Context
-	// TLSConfig holds tls.TLSConfig options
-	TLSConfig *tls.Config
-	// Name holds the transport name
-	Name string
-	// Addrs holds the transport addrs
-	Addrs []string
-	// Timeout holds the timeout
-	Timeout time.Duration
-}
-
-// NewOptions returns new options
-func NewOptions(opts ...Option) Options {
-	options := Options{
-		Logger:  logger.DefaultLogger,
-		Meter:   meter.DefaultMeter,
-		Tracer:  tracer.DefaultTracer,
-		Context: context.Background(),
-	}
-
-	for _, o := range opts {
-		o(&options)
-	}
-
-	return options
-}
-
-// DialOptions struct
-type DialOptions struct {
-	// Context holds the external options
-	Context context.Context
-	// Timeout holds the timeout
-	Timeout time.Duration
-	// Stream flag
-	Stream bool
-}
-
-// NewDialOptions returns new DialOptions
-func NewDialOptions(opts ...DialOption) DialOptions {
-	options := DialOptions{
-		Timeout: DefaultDialTimeout,
-		Context: context.Background(),
-	}
-
-	for _, o := range opts {
-		o(&options)
-	}
-
-	return options
-}
-
-// ListenOptions struct
-type ListenOptions struct {
-	// TODO: add tls options when listening
-	// Currently set in global options
-	// Context holds the external options
-	Context context.Context
-	// TLSConfig holds the *tls.Config options
-	TLSConfig *tls.Config
-}
-
-// NewListenOptions returns new ListenOptions
-func NewListenOptions(opts ...ListenOption) ListenOptions {
-	options := ListenOptions{
-		Context: context.Background(),
-	}
-
-	for _, o := range opts {
-		o(&options)
-	}
-
-	return options
-}
-
-// Addrs to use for transport
-func Addrs(addrs ...string) Option {
-	return func(o *Options) {
-		o.Addrs = addrs
-	}
-}
-
-// Logger sets the logger
-func Logger(l logger.Logger) Option {
-	return func(o *Options) {
-		o.Logger = l
-	}
-}
-
-// Meter sets the meter
-func Meter(m meter.Meter) Option {
-	return func(o *Options) {
-		o.Meter = m
-	}
-}
-
-// Context sets the context
-func Context(ctx context.Context) Option {
-	return func(o *Options) {
-		o.Context = ctx
-	}
-}
-
-// Codec sets the codec used for encoding where the transport
-// does not support message headers
-func Codec(c codec.Codec) Option {
-	return func(o *Options) {
-		o.Codec = c
-	}
-}
-
-// Timeout sets the timeout for Send/Recv execution
-func Timeout(t time.Duration) Option {
-	return func(o *Options) {
-		o.Timeout = t
-	}
-}
-
-// TLSConfig to be used for the transport.
-func TLSConfig(t *tls.Config) Option {
-	return func(o *Options) {
-		o.TLSConfig = t
-	}
-}
-
-// WithStream indicates whether this is a streaming connection
-func WithStream() DialOption {
-	return func(o *DialOptions) {
-		o.Stream = true
-	}
-}
-
-// WithTimeout used when dialling the remote side
-func WithTimeout(d time.Duration) DialOption {
-	return func(o *DialOptions) {
-		o.Timeout = d
-	}
-}
-
-// Tracer to be used for tracing
-func Tracer(t tracer.Tracer) Option {
-	return func(o *Options) {
-		o.Tracer = t
-	}
-}
-
-// Name sets the name
-func Name(n string) Option {
-	return func(o *Options) {
-		o.Name = n
-	}
-}
diff --git a/network/transport/transport.go b/network/transport/transport.go
deleted file mode 100644
index 78333595..00000000
--- a/network/transport/transport.go
+++ /dev/null
@@ -1,63 +0,0 @@
-// Package transport is an interface for synchronous connection based communication
-package transport
-
-import (
-	"context"
-	"time"
-
-	"go.unistack.org/micro/v4/metadata"
-)
-
-var (
-	// DefaultTransport is the global default transport
-	DefaultTransport = NewTransport()
-	// DefaultDialTimeout the default dial timeout
-	DefaultDialTimeout = time.Second * 5
-)
-
-// Transport is an interface which is used for communication between
-// services. It uses connection based socket send/recv semantics and
-// has various implementations; http, grpc, quic.
-type Transport interface {
-	Init(...Option) error
-	Options() Options
-	Dial(ctx context.Context, addr string, opts ...DialOption) (Client, error)
-	Listen(ctx context.Context, addr string, opts ...ListenOption) (Listener, error)
-	String() string
-}
-
-// Message is used to transfer data
-type Message struct {
-	Header metadata.Metadata
-	Body   []byte
-}
-
-// Socket bastraction interface
-type Socket interface {
-	Recv(*Message) error
-	Send(*Message) error
-	Close() error
-	Local() string
-	Remote() string
-}
-
-// Client is the socket owner
-type Client interface {
-	Socket
-}
-
-// Listener is the interface for stream oriented messaging
-type Listener interface {
-	Addr() string
-	Close() error
-	Accept(func(Socket)) error
-}
-
-// Option is the option signature
-type Option func(*Options)
-
-// DialOption is the option signature
-type DialOption func(*DialOptions)
-
-// ListenOption is the option signature
-type ListenOption func(*ListenOptions)
diff --git a/network/tunnel/broker/broker.go b/network/tunnel/broker/broker.go
deleted file mode 100644
index 77ea946d..00000000
--- a/network/tunnel/broker/broker.go
+++ /dev/null
@@ -1,372 +0,0 @@
-// Package broker is a tunnel broker
-package broker
-
-import (
-	"context"
-	"fmt"
-
-	"go.unistack.org/micro/v4/broker"
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/metadata"
-	"go.unistack.org/micro/v4/network/transport"
-	"go.unistack.org/micro/v4/network/tunnel"
-)
-
-type tunBroker struct {
-	tunnel tunnel.Tunnel
-	opts   broker.Options
-}
-
-type tunSubscriber struct {
-	listener tunnel.Listener
-	handler  broker.Handler
-	closed   chan bool
-	topic    string
-	opts     broker.SubscribeOptions
-}
-
-type tunBatchSubscriber struct {
-	listener tunnel.Listener
-	handler  broker.BatchHandler
-	closed   chan bool
-	topic    string
-	opts     broker.SubscribeOptions
-}
-
-type tunEvent struct {
-	err     error
-	message *broker.Message
-	topic   string
-}
-
-// used to access tunnel from options context
-type (
-	tunnelKey  struct{}
-	tunnelAddr struct{}
-)
-
-func (t *tunBroker) Live() bool {
-	return true
-}
-
-func (t *tunBroker) Ready() bool {
-	return true
-}
-
-func (t *tunBroker) Health() bool {
-	return true
-}
-
-func (t *tunBroker) Init(opts ...broker.Option) error {
-	for _, o := range opts {
-		o(&t.opts)
-	}
-	return nil
-}
-
-func (t *tunBroker) Name() string {
-	return t.opts.Name
-}
-
-func (t *tunBroker) Options() broker.Options {
-	return t.opts
-}
-
-func (t *tunBroker) Address() string {
-	return t.tunnel.Address()
-}
-
-func (t *tunBroker) Connect(ctx context.Context) error {
-	return t.tunnel.Connect(ctx)
-}
-
-func (t *tunBroker) Disconnect(ctx context.Context) error {
-	return t.tunnel.Close(ctx)
-}
-
-func (t *tunBroker) BatchPublish(ctx context.Context, msgs []*broker.Message, _ ...broker.PublishOption) error {
-	// TODO: this is probably inefficient, we might want to just maintain an open connection
-	// it may be easier to add broadcast to the tunnel
-	topicMap := make(map[string]tunnel.Session)
-
-	var err error
-	for _, msg := range msgs {
-		topic, _ := msg.Header.Get(metadata.HeaderTopic)
-		c, ok := topicMap[topic]
-		if !ok {
-			c, err = t.tunnel.Dial(ctx, topic, tunnel.DialMode(tunnel.Multicast))
-			if err != nil {
-				return err
-			}
-			defer c.Close()
-			topicMap[topic] = c
-		}
-
-		if err = c.Send(&transport.Message{
-			Header: msg.Header,
-			Body:   msg.Body,
-		}); err != nil {
-			//	msg.SetError(err)
-			return err
-		}
-	}
-
-	return nil
-}
-
-func (t *tunBroker) Publish(ctx context.Context, topic string, m *broker.Message, _ ...broker.PublishOption) error {
-	// TODO: this is probably inefficient, we might want to just maintain an open connection
-	// it may be easier to add broadcast to the tunnel
-	c, err := t.tunnel.Dial(ctx, topic, tunnel.DialMode(tunnel.Multicast))
-	if err != nil {
-		return err
-	}
-	defer c.Close()
-
-	return c.Send(&transport.Message{
-		Header: m.Header,
-		Body:   m.Body,
-	})
-}
-
-func (t *tunBroker) BatchSubscribe(ctx context.Context, topic string, h broker.BatchHandler, opts ...broker.SubscribeOption) (broker.Subscriber, error) {
-	l, err := t.tunnel.Listen(ctx, topic, tunnel.ListenMode(tunnel.Multicast))
-	if err != nil {
-		return nil, err
-	}
-
-	tunSub := &tunBatchSubscriber{
-		topic:    topic,
-		handler:  h,
-		opts:     broker.NewSubscribeOptions(opts...),
-		closed:   make(chan bool),
-		listener: l,
-	}
-
-	// start processing
-	go tunSub.run()
-
-	return tunSub, nil
-}
-
-func (t *tunBroker) Subscribe(ctx context.Context, topic string, h broker.Handler, opts ...broker.SubscribeOption) (broker.Subscriber, error) {
-	l, err := t.tunnel.Listen(ctx, topic, tunnel.ListenMode(tunnel.Multicast))
-	if err != nil {
-		return nil, err
-	}
-
-	tunSub := &tunSubscriber{
-		topic:    topic,
-		handler:  h,
-		opts:     broker.NewSubscribeOptions(opts...),
-		closed:   make(chan bool),
-		listener: l,
-	}
-
-	// start processing
-	go tunSub.run()
-
-	return tunSub, nil
-}
-
-func (t *tunBroker) String() string {
-	return "tunnel"
-}
-
-func (t *tunBatchSubscriber) run() {
-	for {
-		// accept a new connection
-		c, err := t.listener.Accept()
-		if err != nil {
-			select {
-			case <-t.closed:
-				return
-			default:
-				continue
-			}
-		}
-
-		// receive message
-		m := new(transport.Message)
-		if err := c.Recv(m); err != nil {
-			if logger.DefaultLogger.V(logger.ErrorLevel) {
-				logger.DefaultLogger.Error(t.opts.Context, err.Error(), err)
-			}
-			if err = c.Close(); err != nil {
-				if logger.DefaultLogger.V(logger.ErrorLevel) {
-					logger.DefaultLogger.Error(t.opts.Context, err.Error(), err)
-				}
-			}
-			continue
-		}
-
-		// close the connection
-		c.Close()
-
-		evts := broker.Events{&tunEvent{
-			topic: t.topic,
-			message: &broker.Message{
-				Header: m.Header,
-				Body:   m.Body,
-			},
-		}}
-		// handle the message
-		go func() {
-			_ = t.handler(evts)
-		}()
-
-	}
-}
-
-func (t *tunSubscriber) run() {
-	for {
-		// accept a new connection
-		c, err := t.listener.Accept()
-		if err != nil {
-			select {
-			case <-t.closed:
-				return
-			default:
-				continue
-			}
-		}
-
-		// receive message
-		m := new(transport.Message)
-		if err := c.Recv(m); err != nil {
-			if logger.DefaultLogger.V(logger.ErrorLevel) {
-				logger.DefaultLogger.Error(t.opts.Context, err.Error(), err)
-			}
-			if err = c.Close(); err != nil {
-				if logger.DefaultLogger.V(logger.ErrorLevel) {
-					logger.DefaultLogger.Error(t.opts.Context, err.Error(), err)
-				}
-			}
-			continue
-		}
-
-		// close the connection
-		c.Close()
-
-		// handle the message
-		go func() {
-			_ = t.handler(&tunEvent{
-				topic: t.topic,
-				message: &broker.Message{
-					Header: m.Header,
-					Body:   m.Body,
-				},
-			})
-		}()
-	}
-}
-
-func (t *tunBatchSubscriber) Options() broker.SubscribeOptions {
-	return t.opts
-}
-
-func (t *tunBatchSubscriber) Topic() string {
-	return t.topic
-}
-
-func (t *tunBatchSubscriber) Unsubscribe(ctx context.Context) error {
-	select {
-	case <-t.closed:
-		return nil
-	default:
-		close(t.closed)
-		return t.listener.Close()
-	}
-}
-
-func (t *tunSubscriber) Options() broker.SubscribeOptions {
-	return t.opts
-}
-
-func (t *tunSubscriber) Topic() string {
-	return t.topic
-}
-
-func (t *tunSubscriber) Unsubscribe(ctx context.Context) error {
-	select {
-	case <-t.closed:
-		return nil
-	default:
-		close(t.closed)
-		return t.listener.Close()
-	}
-}
-
-func (t *tunEvent) Topic() string {
-	return t.topic
-}
-
-func (t *tunEvent) Message() *broker.Message {
-	return t.message
-}
-
-func (t *tunEvent) Ack() error {
-	return nil
-}
-
-func (t *tunEvent) Error() error {
-	return t.err
-}
-
-func (t *tunEvent) SetError(err error) {
-	t.err = err
-}
-
-func (t *tunEvent) Context() context.Context {
-	return context.TODO()
-}
-
-// NewBroker returns new tunnel broker
-func NewBroker(opts ...broker.Option) (broker.Broker, error) {
-	options := broker.NewOptions(opts...)
-
-	t, ok := options.Context.Value(tunnelKey{}).(tunnel.Tunnel)
-	if !ok {
-		return nil, fmt.Errorf("tunnel not set")
-	}
-
-	a, ok := options.Context.Value(tunnelAddr{}).(string)
-	if ok {
-		// initialise address
-		if err := t.Init(tunnel.Address(a)); err != nil {
-			return nil, err
-		}
-	}
-
-	if len(options.Addrs) > 0 {
-		// initialise nodes
-		if err := t.Init(tunnel.Nodes(options.Addrs...)); err != nil {
-			return nil, err
-		}
-	}
-
-	return &tunBroker{
-		opts:   options,
-		tunnel: t,
-	}, nil
-}
-
-// WithAddress sets the tunnel address
-func WithAddress(a string) broker.Option {
-	return func(o *broker.Options) {
-		if o.Context == nil {
-			o.Context = context.Background()
-		}
-		o.Context = context.WithValue(o.Context, tunnelAddr{}, a)
-	}
-}
-
-// WithTunnel sets the internal tunnel
-func WithTunnel(t tunnel.Tunnel) broker.Option {
-	return func(o *broker.Options) {
-		if o.Context == nil {
-			o.Context = context.Background()
-		}
-		o.Context = context.WithValue(o.Context, tunnelKey{}, t)
-	}
-}
diff --git a/network/tunnel/options.go b/network/tunnel/options.go
deleted file mode 100644
index cf8832ab..00000000
--- a/network/tunnel/options.go
+++ /dev/null
@@ -1,192 +0,0 @@
-package tunnel
-
-import (
-	"time"
-
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v4/network/transport"
-	"go.unistack.org/micro/v4/tracer"
-	"go.unistack.org/micro/v4/util/id"
-)
-
-var (
-	// DefaultAddress is default tunnel bind address
-	DefaultAddress = ":0"
-	// DefaultToken the shared default token
-	DefaultToken = "go.micro.tunnel"
-)
-
-// Option func signature
-type Option func(*Options)
-
-// Options provides network configuration options
-type Options struct {
-	// Logger used for logging
-	Logger logger.Logger
-	// Meter used for metrics
-	Meter meter.Meter
-	// Tracer used for tracing
-	Tracer tracer.Tracer
-	// Transport used for communication
-	Transport transport.Transport
-	// Token the shared auth token
-	Token string
-	// Name holds the tunnel name
-	Name string
-	// ID holds the tunnel id
-	ID string
-	// Address holds the tunnel address
-	Address string
-	// Nodes holds the tunnel nodes
-	Nodes []string
-}
-
-// DialOption func
-type DialOption func(*DialOptions)
-
-// DialOptions provides dial options
-type DialOptions struct {
-	// Link specifies the link to use
-	Link string
-	// specify mode of the session
-	Mode Mode
-	// Wait for connection to be accepted
-	Wait bool
-	// the dial timeout
-	Timeout time.Duration
-}
-
-// ListenOption func
-type ListenOption func(*ListenOptions)
-
-// ListenOptions provides listen options
-type ListenOptions struct {
-	// Mode specify mode of the session
-	Mode Mode
-	// Timeout the read timeout
-	Timeout time.Duration
-}
-
-// ID sets the tunnel id
-func ID(id string) Option {
-	return func(o *Options) {
-		o.ID = id
-	}
-}
-
-// Logger sets the logger
-func Logger(l logger.Logger) Option {
-	return func(o *Options) {
-		o.Logger = l
-	}
-}
-
-// Meter sets the meter
-func Meter(m meter.Meter) Option {
-	return func(o *Options) {
-		o.Meter = m
-	}
-}
-
-// Address sets the tunnel address
-func Address(a string) Option {
-	return func(o *Options) {
-		o.Address = a
-	}
-}
-
-// Nodes specify remote network nodes
-func Nodes(n ...string) Option {
-	return func(o *Options) {
-		o.Nodes = n
-	}
-}
-
-// Token sets the shared token for auth
-func Token(t string) Option {
-	return func(o *Options) {
-		o.Token = t
-	}
-}
-
-// Transport listens for incoming connections
-func Transport(t transport.Transport) Option {
-	return func(o *Options) {
-		o.Transport = t
-	}
-}
-
-// ListenMode option
-func ListenMode(m Mode) ListenOption {
-	return func(o *ListenOptions) {
-		o.Mode = m
-	}
-}
-
-// ListenTimeout for reads and writes on the listener session
-func ListenTimeout(t time.Duration) ListenOption {
-	return func(o *ListenOptions) {
-		o.Timeout = t
-	}
-}
-
-// DialMode multicast sets the multicast option to send only to those mapped
-func DialMode(m Mode) DialOption {
-	return func(o *DialOptions) {
-		o.Mode = m
-	}
-}
-
-// DialTimeout sets the dial timeout of the connection
-func DialTimeout(t time.Duration) DialOption {
-	return func(o *DialOptions) {
-		o.Timeout = t
-	}
-}
-
-// DialLink specifies the link to pin this connection to.
-// This is not applicable if the multicast option is set.
-func DialLink(id string) DialOption {
-	return func(o *DialOptions) {
-		o.Link = id
-	}
-}
-
-// DialWait specifies whether to wait for the connection
-// to be accepted before returning the session
-func DialWait(b bool) DialOption {
-	return func(o *DialOptions) {
-		o.Wait = b
-	}
-}
-
-// NewOptions returns router default options with filled values
-func NewOptions(opts ...Option) Options {
-	options := Options{
-		ID:      id.MustNew(),
-		Address: DefaultAddress,
-		Token:   DefaultToken,
-		Logger:  logger.DefaultLogger,
-		Meter:   meter.DefaultMeter,
-		Tracer:  tracer.DefaultTracer,
-	}
-	for _, o := range opts {
-		o(&options)
-	}
-	return options
-}
-
-// Tracer to be used for tracing
-func Tracer(t tracer.Tracer) Option {
-	return func(o *Options) {
-		o.Tracer = t
-	}
-}
-
-// Name sets the name
-func Name(n string) Option {
-	return func(o *Options) {
-		o.Name = n
-	}
-}
diff --git a/network/tunnel/transport/listener.go b/network/tunnel/transport/listener.go
deleted file mode 100644
index eb506e48..00000000
--- a/network/tunnel/transport/listener.go
+++ /dev/null
@@ -1,30 +0,0 @@
-package transport
-
-import (
-	"go.unistack.org/micro/v4/network/transport"
-	"go.unistack.org/micro/v4/network/tunnel"
-)
-
-type tunListener struct {
-	l tunnel.Listener
-}
-
-func (t *tunListener) Addr() string {
-	return t.l.Channel()
-}
-
-func (t *tunListener) Close() error {
-	return t.l.Close()
-}
-
-func (t *tunListener) Accept(fn func(socket transport.Socket)) error {
-	for {
-		// accept connection
-		c, err := t.l.Accept()
-		if err != nil {
-			return err
-		}
-		// execute the function
-		go fn(c)
-	}
-}
diff --git a/network/tunnel/transport/transport.go b/network/tunnel/transport/transport.go
deleted file mode 100644
index 4b4c0270..00000000
--- a/network/tunnel/transport/transport.go
+++ /dev/null
@@ -1,113 +0,0 @@
-// Package transport provides a tunnel transport
-package transport
-
-import (
-	"context"
-	"fmt"
-
-	"go.unistack.org/micro/v4/network/transport"
-	"go.unistack.org/micro/v4/network/tunnel"
-)
-
-type tunTransport struct {
-	tunnel  tunnel.Tunnel
-	options transport.Options
-}
-
-type tunnelKey struct{}
-
-type transportKey struct{}
-
-func (t *tunTransport) Init(opts ...transport.Option) error {
-	for _, o := range opts {
-		o(&t.options)
-	}
-
-	// close the existing tunnel
-	if t.tunnel != nil {
-		t.tunnel.Close(context.TODO())
-	}
-
-	// get the tunnel
-	tun, ok := t.options.Context.Value(tunnelKey{}).(tunnel.Tunnel)
-	if !ok {
-		return fmt.Errorf("tunnel not set")
-	}
-
-	// get the transport
-	tr, ok := t.options.Context.Value(transportKey{}).(transport.Transport)
-	if ok {
-		_ = tun.Init(tunnel.Transport(tr))
-	}
-
-	// set the tunnel
-	t.tunnel = tun
-
-	return nil
-}
-
-func (t *tunTransport) Dial(ctx context.Context, addr string, opts ...transport.DialOption) (transport.Client, error) {
-	if err := t.tunnel.Connect(ctx); err != nil {
-		return nil, err
-	}
-
-	c, err := t.tunnel.Dial(ctx, addr)
-	if err != nil {
-		return nil, err
-	}
-
-	return c, nil
-}
-
-func (t *tunTransport) Listen(ctx context.Context, addr string, opts ...transport.ListenOption) (transport.Listener, error) {
-	if err := t.tunnel.Connect(ctx); err != nil {
-		return nil, err
-	}
-
-	l, err := t.tunnel.Listen(ctx, addr)
-	if err != nil {
-		return nil, err
-	}
-
-	return &tunListener{l}, nil
-}
-
-func (t *tunTransport) Options() transport.Options {
-	return t.options
-}
-
-func (t *tunTransport) String() string {
-	return "tunnel"
-}
-
-// NewTransport honours the initialiser used in
-func NewTransport(opts ...transport.Option) transport.Transport {
-	t := &tunTransport{
-		options: transport.Options{},
-	}
-
-	// initialise
-	// t.Init(opts...)
-
-	return t
-}
-
-// WithTunnel sets the internal tunnel
-func WithTunnel(t tunnel.Tunnel) transport.Option {
-	return func(o *transport.Options) {
-		if o.Context == nil {
-			o.Context = context.Background()
-		}
-		o.Context = context.WithValue(o.Context, tunnelKey{}, t)
-	}
-}
-
-// WithTransport sets the internal transport
-func WithTransport(t transport.Transport) transport.Option {
-	return func(o *transport.Options) {
-		if o.Context == nil {
-			o.Context = context.Background()
-		}
-		o.Context = context.WithValue(o.Context, transportKey{}, t)
-	}
-}
diff --git a/network/tunnel/tunnel.go b/network/tunnel/tunnel.go
deleted file mode 100644
index f3a9ae96..00000000
--- a/network/tunnel/tunnel.go
+++ /dev/null
@@ -1,106 +0,0 @@
-// Package tunnel provides gre network tunnelling
-package tunnel
-
-import (
-	"context"
-	"errors"
-	"time"
-
-	"go.unistack.org/micro/v4/network/transport"
-)
-
-// DefaultTunnel contains default tunnel implementation
-var DefaultTunnel Tunnel
-
-const (
-	// Unicast send over one link
-	Unicast Mode = iota
-	// Multicast send to all channel listeners
-	Multicast
-	// Broadcast send to all links
-	Broadcast
-)
-
-var (
-	// DefaultDialTimeout is the dial timeout if none is specified
-	DefaultDialTimeout = time.Second * 5
-	// ErrDialTimeout is returned by a call to Dial where the timeout occurs
-	ErrDialTimeout = errors.New("dial timeout")
-	// ErrDiscoverChan is returned when we failed to receive the "announce" back from a discovery
-	ErrDiscoverChan = errors.New("failed to discover channel")
-	// ErrLinkNotFound is returned when a link is specified at dial time and does not exist
-	ErrLinkNotFound = errors.New("link not found")
-	// ErrLinkDisconnected is returned when a link we attempt to send to is disconnected
-	ErrLinkDisconnected = errors.New("link not connected")
-	// ErrLinkLoopback is returned when attempting to send an outbound message over loopback link
-	ErrLinkLoopback = errors.New("link is loopback")
-	// ErrLinkRemote is returned when attempting to send a loopback message over remote link
-	ErrLinkRemote = errors.New("link is remote")
-	// ErrReadTimeout is a timeout on session.Recv
-	ErrReadTimeout = errors.New("read timeout")
-	// ErrDecryptingData is for when theres a nonce error
-	ErrDecryptingData = errors.New("error decrypting data")
-)
-
-// Mode of the session
-type Mode uint8
-
-// Tunnel creates a gre tunnel on top of the micro/transport.
-// It establishes multiple streams using the Micro-Tunnel-Channel header
-// and Micro-Tunnel-Session header. The tunnel id is a hash of
-// the address being requested.
-type Tunnel interface {
-	// Init initializes tunnel with options
-	Init(opts ...Option) error
-	// Address returns the address the tunnel is listening on
-	Address() string
-	// Connect connects the tunnel
-	Connect(ctx context.Context) error
-	// Close closes the tunnel
-	Close(ctx context.Context) error
-	// Links returns all the links the tunnel is connected to
-	Links() []Link
-	// Dial allows a client to connect to a channel
-	Dial(ctx context.Context, channel string, opts ...DialOption) (Session, error)
-	// Listen allows to accept connections on a channel
-	Listen(ctx context.Context, channel string, opts ...ListenOption) (Listener, error)
-	// String returns the name of the tunnel implementation
-	String() string
-}
-
-// Link represents internal links to the tunnel
-type Link interface {
-	// Id returns the link unique Id
-	Id() string
-	// Delay is the current load on the link (lower is better)
-	Delay() int64
-	// Length returns the roundtrip time as nanoseconds (lower is better)
-	Length() int64
-	// Current transfer rate as bits per second (lower is better)
-	Rate() float64
-	// Is this a loopback link
-	Loopback() bool
-	// State of the link: connected/closed/error
-	State() string
-	// honours transport socket
-	transport.Socket
-}
-
-// Listener provides similar constructs to the transport.Listener
-type Listener interface {
-	Accept() (Session, error)
-	Channel() string
-	Close() error
-}
-
-// Session is a unique session created when dialling or accepting connections on the tunnel
-type Session interface {
-	// The unique session id
-	Id() string
-	// The channel name
-	Channel() string
-	// The link the session is on
-	Link() string
-	// a transport socket
-	transport.Socket
-}
diff --git a/proxy/options.go b/proxy/options.go
deleted file mode 100644
index f1d01271..00000000
--- a/proxy/options.go
+++ /dev/null
@@ -1,98 +0,0 @@
-// Package proxy is a transparent proxy built on the micro/server
-package proxy
-
-import (
-	"go.unistack.org/micro/v4/client"
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v4/router"
-	"go.unistack.org/micro/v4/tracer"
-)
-
-// Options for proxy
-type Options struct {
-	// Tracer used for tracing
-	Tracer tracer.Tracer
-	// Client for communication
-	Client client.Client
-	// Router for routing
-	Router router.Router
-	// Logger used for logging
-	Logger logger.Logger
-	// Meter used for metrics
-	Meter meter.Meter
-	// Links holds the communication links
-	Links map[string]client.Client
-	// Endpoint holds the destination address
-	Endpoint string
-}
-
-// Option func signature
-type Option func(o *Options)
-
-// NewOptions returns new options struct that filled by opts
-func NewOptions(opts ...Option) Options {
-	options := Options{
-		Logger: logger.DefaultLogger,
-		Meter:  meter.DefaultMeter,
-		Tracer: tracer.DefaultTracer,
-	}
-
-	for _, o := range opts {
-		o(&options)
-	}
-
-	return options
-}
-
-// WithEndpoint sets a proxy endpoint
-func WithEndpoint(e string) Option {
-	return func(o *Options) {
-		o.Endpoint = e
-	}
-}
-
-// WithClient sets the client
-func WithClient(c client.Client) Option {
-	return func(o *Options) {
-		o.Client = c
-	}
-}
-
-// WithRouter specifies the router to use
-func WithRouter(r router.Router) Option {
-	return func(o *Options) {
-		o.Router = r
-	}
-}
-
-// WithLogger specifies the logger to use
-func WithLogger(l logger.Logger) Option {
-	return func(o *Options) {
-		o.Logger = l
-	}
-}
-
-// WithMeter specifies the meter to use
-func WithMeter(m meter.Meter) Option {
-	return func(o *Options) {
-		o.Meter = m
-	}
-}
-
-// WithLink sets a link for outbound requests
-func WithLink(name string, c client.Client) Option {
-	return func(o *Options) {
-		if o.Links == nil {
-			o.Links = make(map[string]client.Client)
-		}
-		o.Links[name] = c
-	}
-}
-
-// Tracer to be used for tracing
-func Tracer(t tracer.Tracer) Option {
-	return func(o *Options) {
-		o.Tracer = t
-	}
-}
diff --git a/proxy/proxy.go b/proxy/proxy.go
deleted file mode 100644
index bca6c47b..00000000
--- a/proxy/proxy.go
+++ /dev/null
@@ -1,21 +0,0 @@
-// Package proxy is a transparent proxy built on the micro/server
-package proxy
-
-import (
-	"context"
-
-	"go.unistack.org/micro/v4/server"
-)
-
-// DefaultEndpoint holds default proxy address
-var DefaultEndpoint = "localhost:9090"
-
-// Proxy can be used as a proxy server for micro services
-type Proxy interface {
-	// ProcessMessage handles inbound messages
-	ProcessMessage(context.Context, server.Message) error
-	// ServeRequest handles inbound requests
-	ServeRequest(context.Context, server.Request, server.Response) error
-	// Name of the proxy protocol
-	String() string
-}
diff --git a/register/memory/memory.go b/register/memory/memory.go
index 43518e98..2e6f3794 100644
--- a/register/memory/memory.go
+++ b/register/memory/memory.go
@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"go.unistack.org/micro/v4/logger"
+	"go.unistack.org/micro/v4/metadata"
 	"go.unistack.org/micro/v4/register"
 	"go.unistack.org/micro/v4/util/id"
 )
@@ -23,10 +24,9 @@ type node struct {
 }
 
 type record struct {
-	Name     string
-	Version  string
-	Metadata map[string]string
-	Nodes    map[string]*node
+	Name    string
+	Version string
+	Nodes   map[string]*node
 }
 
 type memory struct {
@@ -160,19 +160,14 @@ func (m *memory) Register(_ context.Context, s *register.Service, opts ...regist
 			continue
 		}
 
-		metadata := make(map[string]string, len(n.Metadata))
-
-		// make copy of metadata
-		for k, v := range n.Metadata {
-			metadata[k] = v
-		}
+		md := metadata.Copy(n.Metadata)
 
 		// add the node
 		srvs[s.Name][s.Version].Nodes[n.ID] = &node{
 			Node: &register.Node{
 				ID:       n.ID,
 				Address:  n.Address,
-				Metadata: metadata,
+				Metadata: md,
 			},
 			TTL:      options.TTL,
 			LastSeen: time.Now(),
@@ -452,23 +447,15 @@ func serviceToRecord(s *register.Service, ttl time.Duration) *record {
 }
 
 func recordToService(r *record, namespace string) *register.Service {
-	metadata := make(map[string]string, len(r.Metadata))
-	for k, v := range r.Metadata {
-		metadata[k] = v
-	}
-
 	nodes := make([]*register.Node, len(r.Nodes))
 	i := 0
 	for _, n := range r.Nodes {
-		md := make(map[string]string, len(n.Metadata))
-		for k, v := range n.Metadata {
-			md[k] = v
-		}
+		nmd := metadata.Copy(n.Metadata)
 
 		nodes[i] = &register.Node{
 			ID:       n.ID,
 			Address:  n.Address,
-			Metadata: md,
+			Metadata: nmd,
 		}
 		i++
 	}
diff --git a/server/noop.go b/server/noop.go
index 74d57409..fab5fdc5 100644
--- a/server/noop.go
+++ b/server/noop.go
@@ -1,20 +1,13 @@
 package server
 
 import (
-	"context"
 	"fmt"
 	"reflect"
-	"runtime/debug"
-	"strings"
 	"sync"
 	"time"
 
-	"go.unistack.org/micro/v4/broker"
 	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v4/errors"
 	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/metadata"
-	"go.unistack.org/micro/v4/options"
 	"go.unistack.org/micro/v4/register"
 	maddr "go.unistack.org/micro/v4/util/addr"
 	mnet "go.unistack.org/micro/v4/util/net"
@@ -26,10 +19,6 @@ var DefaultCodecs = map[string]codec.Codec{
 	"application/octet-stream": codec.NewCodec(),
 }
 
-const (
-	defaultContentType = "application/json"
-)
-
 type rpcHandler struct {
 	opts    HandlerOptions
 	handler interface{}
@@ -62,13 +51,12 @@ func (r *rpcHandler) Options() HandlerOptions {
 }
 
 type noopServer struct {
-	h           Handler
-	wg          *sync.WaitGroup
-	rsvc        *register.Service
-	handlers    map[string]Handler
-	subscribers map[*subscriber][]broker.Subscriber
-	exit        chan chan error
-	opts        Options
+	h        Handler
+	wg       *sync.WaitGroup
+	rsvc     *register.Service
+	handlers map[string]Handler
+	exit     chan chan error
+	opts     Options
 	sync.RWMutex
 	registered bool
 	started    bool
@@ -80,25 +68,12 @@ func NewServer(opts ...Option) Server {
 	if n.handlers == nil {
 		n.handlers = make(map[string]Handler)
 	}
-	if n.subscribers == nil {
-		n.subscribers = make(map[*subscriber][]broker.Subscriber)
-	}
 	if n.exit == nil {
 		n.exit = make(chan chan error)
 	}
 	return n
 }
 
-func (n *noopServer) newCodec(contentType string) (codec.Codec, error) {
-	if cf, ok := n.opts.Codecs[contentType]; ok {
-		return cf, nil
-	}
-	if cf, ok := DefaultCodecs[contentType]; ok {
-		return cf, nil
-	}
-	return nil, codec.ErrUnknownContentType
-}
-
 func (n *noopServer) Live() bool {
 	return true
 }
@@ -120,65 +95,10 @@ func (n *noopServer) Name() string {
 	return n.opts.Name
 }
 
-func (n *noopServer) Subscribe(sb Subscriber) error {
-	sub, ok := sb.(*subscriber)
-	if !ok {
-		return fmt.Errorf("invalid subscriber: expected *subscriber")
-	} else if len(sub.handlers) == 0 {
-		return fmt.Errorf("invalid subscriber: no handler functions")
-	}
-
-	if err := ValidateSubscriber(sb); err != nil {
-		return err
-	}
-
-	n.Lock()
-	if _, ok = n.subscribers[sub]; ok {
-		n.Unlock()
-		return fmt.Errorf("subscriber %v already exists", sub)
-	}
-
-	n.subscribers[sub] = nil
-	n.Unlock()
-	return nil
-}
-
-type rpcMessage struct {
-	payload     interface{}
-	codec       codec.Codec
-	header      metadata.Metadata
-	topic       string
-	contentType string
-}
-
-func (r *rpcMessage) ContentType() string {
-	return r.contentType
-}
-
-func (r *rpcMessage) Topic() string {
-	return r.topic
-}
-
-func (r *rpcMessage) Body() interface{} {
-	return r.payload
-}
-
-func (r *rpcMessage) Header() metadata.Metadata {
-	return r.header
-}
-
-func (r *rpcMessage) Codec() codec.Codec {
-	return r.codec
-}
-
 func (n *noopServer) NewHandler(h interface{}, opts ...HandlerOption) Handler {
 	return newRPCHandler(h, opts...)
 }
 
-func (n *noopServer) NewSubscriber(topic string, sb interface{}, opts ...SubscriberOption) Subscriber {
-	return newSubscriber(topic, sb, opts...)
-}
-
 func (n *noopServer) Init(opts ...Option) error {
 	for _, o := range opts {
 		o(&n.opts)
@@ -187,9 +107,6 @@ func (n *noopServer) Init(opts ...Option) error {
 	if n.handlers == nil {
 		n.handlers = make(map[string]Handler, 1)
 	}
-	if n.subscribers == nil {
-		n.subscribers = make(map[*subscriber][]broker.Subscriber, 1)
-	}
 
 	if n.exit == nil {
 		n.exit = make(chan chan error)
@@ -288,33 +205,6 @@ func (n *noopServer) Deregister() error {
 
 	n.registered = false
 
-	cx := config.Context
-
-	wg := sync.WaitGroup{}
-	for sb, subs := range n.subscribers {
-		for idx := range subs {
-			if sb.Options().Context != nil {
-				cx = sb.Options().Context
-			}
-
-			ncx := cx
-			wg.Add(1)
-			go func(s broker.Subscriber) {
-				defer wg.Done()
-				if config.Logger.V(logger.InfoLevel) {
-					config.Logger.Info(n.opts.Context, "unsubscribing from topic: "+s.Topic())
-				}
-				if err := s.Unsubscribe(ncx); err != nil {
-					if config.Logger.V(logger.ErrorLevel) {
-						config.Logger.Error(n.opts.Context, "unsubscribing from topic: "+s.Topic(), err)
-					}
-				}
-			}(subs[idx])
-		}
-		n.subscribers[sb] = nil
-	}
-	wg.Wait()
-
 	n.Unlock()
 	return nil
 }
@@ -351,21 +241,6 @@ func (n *noopServer) Start() error {
 	}
 	n.Unlock()
 
-	// only connect if we're subscribed
-	if len(n.subscribers) > 0 {
-		// connect to the broker
-		if err := config.Broker.Connect(config.Context); err != nil {
-			if config.Logger.V(logger.ErrorLevel) {
-				config.Logger.Error(n.opts.Context, fmt.Sprintf("broker [%s] connect error", config.Broker.String()), err)
-			}
-			return err
-		}
-
-		if config.Logger.V(logger.InfoLevel) {
-			config.Logger.Info(n.opts.Context, fmt.Sprintf("broker [%s] Connected to %s", config.Broker.String(), config.Broker.Address()))
-		}
-	}
-
 	// use RegisterCheck func before register
 	// nolint: nestif
 	if err := config.RegisterCheck(config.Context); err != nil {
@@ -381,10 +256,6 @@ func (n *noopServer) Start() error {
 		}
 	}
 
-	if err := n.subscribe(); err != nil {
-		return err
-	}
-
 	go func() {
 		t := new(time.Ticker)
 
@@ -468,42 +339,6 @@ func (n *noopServer) Start() error {
 	return nil
 }
 
-func (n *noopServer) subscribe() error {
-	config := n.Options()
-
-	subCtx := config.Context
-
-	for sb := range n.subscribers {
-
-		if cx := sb.Options().Context; cx != nil {
-			subCtx = cx
-		}
-
-		opts := []broker.SubscribeOption{
-			broker.SubscribeContext(subCtx),
-			broker.SubscribeAutoAck(sb.Options().AutoAck),
-			broker.SubscribeBodyOnly(sb.Options().BodyOnly),
-		}
-
-		if queue := sb.Options().Queue; len(queue) > 0 {
-			opts = append(opts, broker.SubscribeGroup(queue))
-		}
-
-		if config.Logger.V(logger.InfoLevel) {
-			config.Logger.Info(n.opts.Context, "subscribing to topic: "+sb.Topic())
-		}
-
-		sub, err := config.Broker.Subscribe(subCtx, sb.Topic(), n.createSubHandler(sb, config), opts...)
-		if err != nil {
-			return err
-		}
-
-		n.subscribers[sb] = []broker.Subscriber{sub}
-	}
-
-	return nil
-}
-
 func (n *noopServer) Stop() error {
 	n.RLock()
 	if !n.started {
@@ -523,195 +358,3 @@ func (n *noopServer) Stop() error {
 
 	return err
 }
-
-func newSubscriber(topic string, sub interface{}, opts ...SubscriberOption) Subscriber {
-	var handlers []*handler
-
-	options := NewSubscriberOptions(opts...)
-
-	if typ := reflect.TypeOf(sub); typ.Kind() == reflect.Func {
-		h := &handler{
-			method: reflect.ValueOf(sub),
-		}
-
-		switch typ.NumIn() {
-		case 1:
-			h.reqType = typ.In(0)
-		case 2:
-			h.ctxType = typ.In(0)
-			h.reqType = typ.In(1)
-		}
-
-		handlers = append(handlers, h)
-	} else {
-		for m := 0; m < typ.NumMethod(); m++ {
-			method := typ.Method(m)
-			h := &handler{
-				method: method.Func,
-			}
-
-			switch method.Type.NumIn() {
-			case 2:
-				h.reqType = method.Type.In(1)
-			case 3:
-				h.ctxType = method.Type.In(1)
-				h.reqType = method.Type.In(2)
-			}
-
-			handlers = append(handlers, h)
-		}
-	}
-
-	return &subscriber{
-		rcvr:       reflect.ValueOf(sub),
-		typ:        reflect.TypeOf(sub),
-		topic:      topic,
-		subscriber: sub,
-		handlers:   handlers,
-		opts:       options,
-	}
-}
-
-//nolint:gocyclo
-func (n *noopServer) createSubHandler(sb *subscriber, opts Options) broker.Handler {
-	return func(p broker.Event) (err error) {
-		defer func() {
-			if r := recover(); r != nil {
-				n.RLock()
-				config := n.opts
-				n.RUnlock()
-				if config.Logger.V(logger.ErrorLevel) {
-					config.Logger.Error(n.opts.Context, "panic recovered: ", r)
-					config.Logger.Error(n.opts.Context, string(debug.Stack()))
-				}
-				err = errors.InternalServerError(n.opts.Name+".subscriber", "panic recovered: %v", r)
-			}
-		}()
-
-		msg := p.Message()
-		// if we don't have headers, create empty map
-		if msg.Header == nil {
-			msg.Header = metadata.New(2)
-		}
-
-		ct := msg.Header["Content-Type"]
-		if len(ct) == 0 {
-			msg.Header.Set(metadata.HeaderContentType, defaultContentType)
-			ct = defaultContentType
-		}
-		cf, err := n.newCodec(ct)
-		if err != nil {
-			return err
-		}
-
-		hdr := metadata.New(len(msg.Header))
-		for k, v := range msg.Header {
-			hdr.Set(k, v)
-		}
-
-		ctx := metadata.NewIncomingContext(sb.opts.Context, hdr)
-
-		results := make(chan error, len(sb.handlers))
-
-		for i := 0; i < len(sb.handlers); i++ {
-			handler := sb.handlers[i]
-
-			var isVal bool
-			var req reflect.Value
-
-			if handler.reqType.Kind() == reflect.Ptr {
-				req = reflect.New(handler.reqType.Elem())
-			} else {
-				req = reflect.New(handler.reqType)
-				isVal = true
-			}
-			if isVal {
-				req = req.Elem()
-			}
-
-			if err = cf.Unmarshal(msg.Body, req.Interface()); err != nil {
-				return err
-			}
-
-			fn := func(ctx context.Context, msg Message) error {
-				var vals []reflect.Value
-				if sb.typ.Kind() != reflect.Func {
-					vals = append(vals, sb.rcvr)
-				}
-				if handler.ctxType != nil {
-					vals = append(vals, reflect.ValueOf(ctx))
-				}
-
-				vals = append(vals, reflect.ValueOf(msg.Body()))
-
-				returnValues := handler.method.Call(vals)
-				if rerr := returnValues[0].Interface(); rerr != nil {
-					return rerr.(error)
-				}
-				return nil
-			}
-
-			opts.Hooks.EachPrev(func(hook options.Hook) {
-				if h, ok := hook.(HookSubHandler); ok {
-					fn = h(fn)
-				}
-			})
-
-			if n.wg != nil {
-				n.wg.Add(1)
-			}
-			go func() {
-				if n.wg != nil {
-					defer n.wg.Done()
-				}
-				cerr := fn(ctx, &rpcMessage{
-					topic:       sb.topic,
-					contentType: ct,
-					payload:     req.Interface(),
-					header:      msg.Header,
-				})
-				results <- cerr
-			}()
-		}
-		var errors []string
-		for i := 0; i < len(sb.handlers); i++ {
-			if rerr := <-results; rerr != nil {
-				errors = append(errors, rerr.Error())
-			}
-		}
-		if len(errors) > 0 {
-			err = fmt.Errorf("subscriber error: %s", strings.Join(errors, "\n"))
-		}
-		return err
-	}
-}
-
-func (s *subscriber) Topic() string {
-	return s.topic
-}
-
-func (s *subscriber) Subscriber() interface{} {
-	return s.subscriber
-}
-
-func (s *subscriber) Options() SubscriberOptions {
-	return s.opts
-}
-
-type subscriber struct {
-	topic string
-
-	typ        reflect.Type
-	subscriber interface{}
-
-	handlers []*handler
-
-	rcvr reflect.Value
-	opts SubscriberOptions
-}
-
-type handler struct {
-	reqType reflect.Type
-	ctxType reflect.Type
-	method  reflect.Value
-}
diff --git a/server/noop_test.go b/server/noop_test.go
deleted file mode 100644
index 2752e6ff..00000000
--- a/server/noop_test.go
+++ /dev/null
@@ -1,124 +0,0 @@
-package server_test
-
-import (
-	"context"
-	"fmt"
-	"testing"
-
-	"go.unistack.org/micro/v4/broker"
-	"go.unistack.org/micro/v4/client"
-	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v4/options"
-	"go.unistack.org/micro/v4/server"
-)
-
-type TestHandler struct {
-	t *testing.T
-}
-
-type TestMessage struct {
-	Name string
-}
-
-func (h *TestHandler) SingleSubHandler(ctx context.Context, msg *codec.Frame) error {
-	// fmt.Printf("msg %s\n", msg.Data)
-	return nil
-}
-
-func TestNoopSub(t *testing.T) {
-	ctx := context.Background()
-
-	b := broker.NewBroker()
-
-	if err := b.Init(); err != nil {
-		t.Fatal(err)
-	}
-
-	if err := b.Connect(ctx); err != nil {
-		t.Fatal(err)
-	}
-
-	if err := logger.DefaultLogger.Init(logger.WithLevel(logger.ErrorLevel)); err != nil {
-		t.Fatal(err)
-	}
-	s := server.NewServer(
-		server.Broker(b),
-		server.Codec("application/octet-stream", codec.NewCodec()),
-	)
-	if err := s.Init(); err != nil {
-		t.Fatal(err)
-	}
-
-	c := client.NewClient(
-		client.Broker(b),
-		client.Codec("application/octet-stream", codec.NewCodec()),
-		client.ContentType("application/octet-stream"),
-	)
-	if err := c.Init(); err != nil {
-		t.Fatal(err)
-	}
-	h := &TestHandler{t: t}
-
-	if err := s.Subscribe(s.NewSubscriber("single_topic", h.SingleSubHandler,
-		server.SubscriberQueue("queue"),
-	)); err != nil {
-		t.Fatal(err)
-	}
-
-	if err := s.Start(); err != nil {
-		t.Fatal(err)
-	}
-
-	msgs := make([]client.Message, 0, 8)
-	for i := 0; i < 8; i++ {
-		msgs = append(msgs, c.NewMessage("batch_topic", &codec.Frame{Data: []byte(fmt.Sprintf(`{"name": "test_name %d"}`, i))}))
-	}
-
-	if err := c.BatchPublish(ctx, msgs); err != nil {
-		t.Fatal(err)
-	}
-
-	defer func() {
-		if err := s.Stop(); err != nil {
-			t.Fatal(err)
-		}
-	}()
-}
-
-func TestHooks_Wrap(t *testing.T) {
-	n := 5
-	fn1 := func(next server.FuncSubHandler) server.FuncSubHandler {
-		return func(ctx context.Context, msg server.Message) (err error) {
-			n *= 2
-			return next(ctx, msg)
-		}
-	}
-	fn2 := func(next server.FuncSubHandler) server.FuncSubHandler {
-		return func(ctx context.Context, msg server.Message) (err error) {
-			n -= 10
-			return next(ctx, msg)
-		}
-	}
-
-	hs := &options.Hooks{}
-	hs.Append(server.HookSubHandler(fn1), server.HookSubHandler(fn2))
-
-	var fn = func(ctx context.Context, msg server.Message) error {
-		return nil
-	}
-
-	hs.EachPrev(func(hook options.Hook) {
-		if h, ok := hook.(server.HookSubHandler); ok {
-			fn = h(fn)
-		}
-	})
-
-	if err := fn(nil, nil); err != nil {
-		t.Fatal(err)
-	}
-
-	if n != 0 {
-		t.Fatalf("uncorrected hooks call")
-	}
-}
diff --git a/server/registry.go b/server/registry.go
index a6d34fed..9d4bf7dc 100644
--- a/server/registry.go
+++ b/server/registry.go
@@ -77,10 +77,6 @@ func NewRegisterService(s Server) (*register.Service, error) {
 	}
 	node.Metadata = metadata.Copy(opts.Metadata)
 
-	node.Metadata["server"] = s.String()
-	node.Metadata["broker"] = opts.Broker.String()
-	node.Metadata["register"] = opts.Register.String()
-
 	return &register.Service{
 		Name:    opts.Name,
 		Version: opts.Version,
diff --git a/server/server.go b/server/server.go
index 4648a0f8..14f8acb4 100644
--- a/server/server.go
+++ b/server/server.go
@@ -3,6 +3,7 @@ package server
 
 import (
 	"context"
+	"errors"
 	"time"
 
 	"go.unistack.org/micro/v4/codec"
@@ -51,10 +52,6 @@ type Server interface {
 	Handle(h Handler) error
 	// Create a new handler
 	NewHandler(h interface{}, opts ...HandlerOption) Handler
-	// Create a new subscriber
-	NewSubscriber(topic string, h interface{}, opts ...SubscriberOption) Subscriber
-	// Register a subscriber
-	Subscribe(s Subscriber) error
 	// Start the server
 	Start() error
 	// Stop the server
@@ -70,36 +67,10 @@ type Server interface {
 }
 
 type (
-	FuncSubHandler func(ctx context.Context, ms Message) error
-	HookSubHandler func(next FuncSubHandler) FuncSubHandler
-	FuncHandler    func(ctx context.Context, req Request, rsp interface{}) error
-	HookHandler    func(next FuncHandler) FuncHandler
+	FuncHandler func(ctx context.Context, req Request, rsp interface{}) error
+	HookHandler func(next FuncHandler) FuncHandler
 )
 
-/*
-// Router handle serving messages
-type Router interface {
-	// ProcessMessage processes a message
-	ProcessMessage(ctx context.Context, msg Message) error
-	// ServeRequest processes a request to completion
-	ServeRequest(ctx context.Context, req Request, rsp Response) error
-}
-*/
-
-// Message is an async message interface
-type Message interface {
-	// Topic of the message
-	Topic() string
-	// The decoded payload value
-	Body() interface{}
-	// The content type of the payload
-	ContentType() string
-	// The raw headers of the message
-	Header() metadata.Metadata
-	// Codec used to decode the message
-	Codec() codec.Codec
-}
-
 // Request is a synchronous request interface
 type Request interface {
 	// Service name requested
@@ -172,11 +143,20 @@ type Handler interface {
 	Options() HandlerOptions
 }
 
-// Subscriber interface represents a subscription to a given topic using
-// a specific subscriber function or object with endpoints. It mirrors
-// the handler in its behaviour.
-type Subscriber interface {
-	Topic() string
-	Subscriber() interface{}
-	Options() SubscriberOptions
+type serverHeaderKey struct{}
+
+func ResponseMetadata(ctx context.Context, md *metadata.Metadata) context.Context {
+	return context.WithValue(ctx, serverHeaderKey{}, md)
+}
+
+func SetResponseMetadata(ctx context.Context, md metadata.Metadata) error {
+	if md.Len() == 0 {
+		return nil
+	}
+	h, ok := ctx.Value(serverHeaderKey{}).(*metadata.Metadata)
+	if !ok || h == nil {
+		return errors.New("missing metadata")
+	}
+	md.CopyTo(*h)
+	return nil
 }
diff --git a/server/wrapper.go b/server/wrapper.go
index 3e4d3ecd..3500dc78 100644
--- a/server/wrapper.go
+++ b/server/wrapper.go
@@ -9,17 +9,9 @@ import (
 // request and response types.
 type HandlerFunc func(ctx context.Context, req Request, rsp interface{}) error
 
-// SubscriberFunc represents a single method of a subscriber. It's used primarily
-// for the wrappers. What's handed to the actual method is the concrete
-// publication message.
-type SubscriberFunc func(ctx context.Context, msg Message) error
-
 // HandlerWrapper wraps the HandlerFunc and returns the equivalent
 type HandlerWrapper func(HandlerFunc) HandlerFunc
 
-// SubscriberWrapper wraps the SubscriberFunc and returns the equivalent
-type SubscriberWrapper func(SubscriberFunc) SubscriberFunc
-
 // StreamWrapper wraps a Stream interface and returns the equivalent.
 // Because streams exist for the lifetime of a method invocation this
 // is a convenient way to wrap a Stream as its in use for trace, monitoring,
diff --git a/service.go b/service.go
index 7ba61843..1ea4c29d 100644
--- a/service.go
+++ b/service.go
@@ -95,11 +95,6 @@ func RegisterHandler(s server.Server, h interface{}, opts ...server.HandlerOptio
 	return s.Handle(s.NewHandler(h, opts...))
 }
 
-// RegisterSubscriber is syntactic sugar for registering a subscriber
-func RegisterSubscriber(topic string, s server.Server, h interface{}, opts ...server.SubscriberOption) error {
-	return s.Subscribe(s.NewSubscriber(topic, h, opts...))
-}
-
 type service struct {
 	done chan struct{}
 	opts Options
diff --git a/service_test.go b/service_test.go
index 32370619..9dff6262 100644
--- a/service_test.go
+++ b/service_test.go
@@ -1,7 +1,6 @@
 package micro
 
 import (
-	"context"
 	"reflect"
 	"testing"
 
@@ -80,41 +79,6 @@ func TestRegisterHandler(t *testing.T) {
 	}
 }
 
-func TestRegisterSubscriber(t *testing.T) {
-	type args struct {
-		topic string
-		s     server.Server
-		h     interface{}
-		opts  []server.SubscriberOption
-	}
-	h := func(_ context.Context, _ interface{}) error {
-		return nil
-	}
-	tests := []struct {
-		name    string
-		args    args
-		wantErr bool
-	}{
-		{
-			name: "RegisterSubscriber",
-			args: args{
-				topic: "test",
-				s:     server.DefaultServer,
-				h:     h,
-				opts:  nil,
-			},
-			wantErr: false,
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			if err := RegisterSubscriber(tt.args.topic, tt.args.s, tt.args.h, tt.args.opts...); (err != nil) != tt.wantErr {
-				t.Errorf("RegisterSubscriber() error = %v, wantErr %v", err, tt.wantErr)
-			}
-		})
-	}
-}
-
 func TestNewService(t *testing.T) {
 	type args struct {
 		opts []Option
diff --git a/util/socket/pool.go b/util/socket/pool.go
deleted file mode 100644
index 462ce883..00000000
--- a/util/socket/pool.go
+++ /dev/null
@@ -1,65 +0,0 @@
-package socket
-
-import (
-	"sync"
-)
-
-// Pool holds the socket pool
-type Pool struct {
-	pool map[string]*Socket
-	sync.RWMutex
-}
-
-// Get socket from pool
-func (p *Pool) Get(id string) (*Socket, bool) {
-	// attempt to get existing socket
-	p.RLock()
-	socket, ok := p.pool[id]
-	if ok {
-		p.RUnlock()
-		return socket, ok
-	}
-	p.RUnlock()
-
-	// save socket
-	p.Lock()
-	defer p.Unlock()
-	// double checked locking
-	socket, ok = p.pool[id]
-	if ok {
-		return socket, ok
-	}
-	// create new socket
-	socket = New(id)
-	p.pool[id] = socket
-
-	// return socket
-	return socket, false
-}
-
-// Release close the socket and delete from pool
-func (p *Pool) Release(s *Socket) {
-	p.Lock()
-	defer p.Unlock()
-
-	// close the socket
-	s.Close()
-	delete(p.pool, s.id)
-}
-
-// Close the pool and delete all the sockets
-func (p *Pool) Close() {
-	p.Lock()
-	defer p.Unlock()
-	for id, sock := range p.pool {
-		sock.Close()
-		delete(p.pool, id)
-	}
-}
-
-// NewPool returns a new socket pool
-func NewPool() *Pool {
-	return &Pool{
-		pool: make(map[string]*Socket),
-	}
-}
diff --git a/util/socket/socket.go b/util/socket/socket.go
deleted file mode 100644
index b36036e6..00000000
--- a/util/socket/socket.go
+++ /dev/null
@@ -1,118 +0,0 @@
-// Package socket provides a pseudo socket
-package socket
-
-import (
-	"io"
-
-	"go.unistack.org/micro/v4/network/transport"
-)
-
-// Socket is our pseudo socket for transport.Socket
-type Socket struct {
-	closed chan bool
-	send   chan *transport.Message
-	recv   chan *transport.Message
-	id     string
-	remote string
-	local  string
-}
-
-// SetLocal sets the local addr
-func (s *Socket) SetLocal(l string) {
-	s.local = l
-}
-
-// SetRemote sets the remote addr
-func (s *Socket) SetRemote(r string) {
-	s.remote = r
-}
-
-// Accept passes a message to the socket which will be processed by the call to Recv
-func (s *Socket) Accept(m *transport.Message) error {
-	select {
-	case s.recv <- m:
-		return nil
-	case <-s.closed:
-		return io.EOF
-	}
-}
-
-// Process takes the next message off the send queue created by a call to Send
-func (s *Socket) Process(m *transport.Message) error {
-	select {
-	case msg := <-s.send:
-		*m = *msg
-	case <-s.closed:
-		// see if we need to drain
-		select {
-		case msg := <-s.send:
-			*m = *msg
-			return nil
-		default:
-			return io.EOF
-		}
-	}
-	return nil
-}
-
-// Remote returns remote addr
-func (s *Socket) Remote() string {
-	return s.remote
-}
-
-// Local returns local addr
-func (s *Socket) Local() string {
-	return s.local
-}
-
-// Send message by via transport
-func (s *Socket) Send(m *transport.Message) error {
-	// send a message
-	select {
-	case s.send <- m:
-	case <-s.closed:
-		return io.EOF
-	}
-
-	return nil
-}
-
-// Recv message from transport
-func (s *Socket) Recv(m *transport.Message) error {
-	// receive a message
-	select {
-	case msg := <-s.recv:
-		// set message
-		*m = *msg
-	case <-s.closed:
-		return io.EOF
-	}
-
-	// return nil
-	return nil
-}
-
-// Close closes the socket
-func (s *Socket) Close() error {
-	select {
-	case <-s.closed:
-		// no op
-	default:
-		close(s.closed)
-	}
-	return nil
-}
-
-// New returns a new pseudo socket which can be used in the place of a transport socket.
-// Messages are sent to the socket via Accept and receives from the socket via Process.
-// SetLocal/SetRemote should be called before using the socket.
-func New(id string) *Socket {
-	return &Socket{
-		id:     id,
-		closed: make(chan bool),
-		local:  "local",
-		remote: "remote",
-		send:   make(chan *transport.Message, 128),
-		recv:   make(chan *transport.Message, 128),
-	}
-}