diff --git a/codec.go b/codec.go
index 7111807..6181259 100644
--- a/codec.go
+++ b/codec.go
@@ -1,7 +1,7 @@
 package grpc
 
 import (
-	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v4/codec"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/encoding"
 )
diff --git a/codec_test.go b/codec_test.go
index 54b9e90..d08644f 100644
--- a/codec_test.go
+++ b/codec_test.go
@@ -2,9 +2,10 @@ package grpc
 
 import (
 	"context"
-	"go.unistack.org/micro/v3/codec"
-	gmetadata "google.golang.org/grpc/metadata"
 	"testing"
+
+	"go.unistack.org/micro/v4/codec"
+	gmetadata "google.golang.org/grpc/metadata"
 )
 
 type mockStream struct {
diff --git a/error.go b/error.go
index 3b18158..f0b5ba7 100644
--- a/error.go
+++ b/error.go
@@ -1,7 +1,7 @@
 package grpc
 
 import (
-	"go.unistack.org/micro/v3/errors"
+	"go.unistack.org/micro/v4/errors"
 	"google.golang.org/grpc/status"
 )
 
diff --git a/go.mod b/go.mod
index c00881f..a6fc461 100644
--- a/go.mod
+++ b/go.mod
@@ -1,19 +1,24 @@
-module go.unistack.org/micro-client-grpc/v3
+module go.unistack.org/micro-client-grpc/v4
 
-go 1.21
+go 1.23.0
 
-toolchain go1.23.1
+toolchain go1.23.3
 
 require (
-	go.unistack.org/micro/v3 v3.10.91
-	google.golang.org/grpc v1.67.0
+	go.unistack.org/micro/v4 v4.1.2
+	google.golang.org/grpc v1.70.0
 )
 
 require (
-	go.unistack.org/micro-proto/v3 v3.4.1 // indirect
-	golang.org/x/net v0.29.0 // indirect
-	golang.org/x/sys v0.25.0 // indirect
-	golang.org/x/text v0.18.0 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20240903143218-8af14fe29dc1 // indirect
-	google.golang.org/protobuf v1.34.2 // indirect
+	github.com/ash3in/uuidv8 v1.2.0 // indirect
+	github.com/google/uuid v1.6.0 // indirect
+	github.com/matoous/go-nanoid v1.5.1 // indirect
+	github.com/spf13/cast v1.7.1 // indirect
+	go.unistack.org/micro-proto/v4 v4.1.0 // indirect
+	golang.org/x/net v0.35.0 // indirect
+	golang.org/x/sys v0.30.0 // indirect
+	golang.org/x/text v0.22.0 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20250224174004-546df14abb99 // indirect
+	google.golang.org/protobuf v1.36.5 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
diff --git a/go.sum b/go.sum
index d8f1cd0..5710689 100644
--- a/go.sum
+++ b/go.sum
@@ -1,18 +1,57 @@
+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/ash3in/uuidv8 v1.2.0 h1:2oogGdtCPwaVtyvPPGin4TfZLtOGE5F+W++E880G6SI=
+github.com/ash3in/uuidv8 v1.2.0/go.mod h1:BnU0wJBxnzdEKmVg4xckBkD+VZuecTFTUP3M0dWgyY4=
+github.com/frankban/quicktest v1.14.6 h1:7Xjx+VpznH+oBnejlPUj8oUpdxnVs4f8XU8WnHkI4W8=
+github.com/frankban/quicktest v1.14.6/go.mod h1:4ptaffx2x8+WTWXmUCuVU6aPUX1/Mz7zb5vbUoiM6w0=
+github.com/go-logr/logr v1.4.2 h1:6pFjapn8bFcIbiKo3XT4j/BhANplGihG6tvd+8rYgrY=
+github.com/go-logr/logr v1.4.2/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
+github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
+github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
+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=
-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=
-go.unistack.org/micro/v3 v3.10.91 h1:vuJY4tXwpqimwIkEJ3TozMYNVQQs+C5QMlQWPgSY/YM=
-go.unistack.org/micro/v3 v3.10.91/go.mod h1:erMgt3Bl7vQQ0e9UpQyR5NlLiZ9pKeEJ9+1tfYFaqUg=
-golang.org/x/net v0.29.0 h1:5ORfpBpCs4HzDYoodCDBbwHzdR5UrLBZ3sOnUJmFoHo=
-golang.org/x/net v0.29.0/go.mod h1:gLkgy8jTGERgjzMic6DS9+SP0ajcu6Xu3Orq/SpETg0=
-golang.org/x/sys v0.25.0 h1:r+8e+loiHxRqhXVl6ML1nO3l1+oFoWbnlu2Ehimmi34=
-golang.org/x/sys v0.25.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/text v0.18.0 h1:XvMDiNzPAl0jr17s6W9lcaIhGUfUORdGCNsuLmPG224=
-golang.org/x/text v0.18.0/go.mod h1:BuEKDfySbSR4drPmRPG/7iBdf8hvFMuRexcpahXilzY=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20240903143218-8af14fe29dc1 h1:pPJltXNxVzT4pK9yD8vR9X75DaWYYmLGMsEvBfFQZzQ=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20240903143218-8af14fe29dc1/go.mod h1:UqMtugtsSgubUsoxbuAoiCXvqvErP7Gf0so0mK9tHxU=
-google.golang.org/grpc v1.67.0 h1:IdH9y6PF5MPSdAntIcpjQ+tXO41pcQsfZV2RxtQgVcw=
-google.golang.org/grpc v1.67.0/go.mod h1:1gLDyUQU7CTLJI90u3nXZ9ekeghjeM7pTDZlqFNg2AA=
-google.golang.org/protobuf v1.34.2 h1:6xV6lTsCfpGD21XK49h7MhtcApnLqkfYgPcdHftf6hg=
-google.golang.org/protobuf v1.34.2/go.mod h1:qYOHts0dSfpeUzUFpOMr/WGzszTmLH+DiWniOlNbLDw=
+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/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
+github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
+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/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/spf13/cast v1.7.1 h1:cuNEagBQEHWN1FnbGEjCXL2szYEXqfJPbP2HNUaca9Y=
+github.com/spf13/cast v1.7.1/go.mod h1:ancEpBxwJDODSW/UG4rDrAqiKolqNNh2DX3mk86cAdo=
+go.opentelemetry.io/otel v1.32.0 h1:WnBN+Xjcteh0zdk01SVqV55d/m62NJLJdIyb4y/WO5U=
+go.opentelemetry.io/otel v1.32.0/go.mod h1:00DCVSB0RQcnzlwyTfqtxSm+DRr9hpYrHjNGiBHVQIg=
+go.opentelemetry.io/otel/metric v1.32.0 h1:xV2umtmNcThh2/a/aCP+h64Xx5wsj8qqnkYZktzNa0M=
+go.opentelemetry.io/otel/metric v1.32.0/go.mod h1:jH7CIbbK6SH2V2wE16W05BHCtIDzauciCRLoc/SyMv8=
+go.opentelemetry.io/otel/sdk v1.32.0 h1:RNxepc9vK59A8XsgZQouW8ue8Gkb4jpWtJm9ge5lEG4=
+go.opentelemetry.io/otel/sdk v1.32.0/go.mod h1:LqgegDBjKMmb2GC6/PrTnteJG39I8/vJCAP9LlJXEjU=
+go.opentelemetry.io/otel/sdk/metric v1.32.0 h1:rZvFnvmvawYb0alrYkjraqJq0Z4ZUJAiyYCU9snn1CU=
+go.opentelemetry.io/otel/sdk/metric v1.32.0/go.mod h1:PWeZlq0zt9YkYAp3gjKZ0eicRYvOh1Gd+X99x6GHpCQ=
+go.opentelemetry.io/otel/trace v1.32.0 h1:WIC9mYrXf8TmY/EXuULKc8hR17vE+Hjv2cssQDe03fM=
+go.opentelemetry.io/otel/trace v1.32.0/go.mod h1:+i4rkvCraA+tG6AzwloGaCtkx53Fa+L+V8e9a7YvhT8=
+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=
+go.unistack.org/micro/v4 v4.1.2 h1:9SOlPYyPNNFpg1A7BsvhDyQm3gysLH1AhWbDCp1hyoY=
+go.unistack.org/micro/v4 v4.1.2/go.mod h1:lr3oYED8Ay1vjK68QqRw30QOtdk/ffpZqMFDasOUhKw=
+golang.org/x/net v0.35.0 h1:T5GQRQb2y08kTAByq9L4/bz8cipCdA8FbRTXewonqY8=
+golang.org/x/net v0.35.0/go.mod h1:EglIi67kWsHKlRzzVMUD93VMSWGFOMSZgxFjparz1Qk=
+golang.org/x/sys v0.30.0 h1:QjkSwP/36a20jFYWkSue1YwXzLmsV5Gfq7Eiy72C1uc=
+golang.org/x/sys v0.30.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/text v0.22.0 h1:bofq7m3/HAFvbF51jz3Q9wLg3jkvSPuiZu/pD1XwgtM=
+golang.org/x/text v0.22.0/go.mod h1:YRoo4H8PVmsu+E3Ou7cqLVH8oXWIHVoX0jqUWALQhfY=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20250224174004-546df14abb99 h1:ZSlhAUqC4r8TPzqLXQ0m3upBNZeF+Y8jQ3c4CR3Ujms=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20250224174004-546df14abb99/go.mod h1:LuRYeWDFV6WOn90g357N17oMCaxpgCnbi/44qJvDn2I=
+google.golang.org/grpc v1.70.0 h1:pWFv03aZoHzlRKHWicjsZytKAiYCtNS0dHbXnIdq7jQ=
+google.golang.org/grpc v1.70.0/go.mod h1:ofIJqVKDXx/JiXrwr2IG4/zwdH9txy3IlF40RmcJSQw=
+google.golang.org/protobuf v1.36.5 h1:tPhr+woSbjfYvY6/GPufUoYizxw1cF/yFoxJ2fmpwlM=
+google.golang.org/protobuf v1.36.5/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 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/grpc.go b/grpc.go
index d80a072..b0fd4c3 100644
--- a/grpc.go
+++ b/grpc.go
@@ -6,22 +6,20 @@ import (
 	"crypto/tls"
 	"fmt"
 	"net"
-	"os"
 	"reflect"
 	"strconv"
 	"strings"
 	"sync"
 	"time"
 
-	"go.unistack.org/micro/v3/broker"
-	"go.unistack.org/micro/v3/client"
-	"go.unistack.org/micro/v3/codec"
-	"go.unistack.org/micro/v3/errors"
-	"go.unistack.org/micro/v3/metadata"
-	"go.unistack.org/micro/v3/options"
-	"go.unistack.org/micro/v3/selector"
-	"go.unistack.org/micro/v3/semconv"
-	"go.unistack.org/micro/v3/tracer"
+	"go.unistack.org/micro/v4/client"
+	"go.unistack.org/micro/v4/codec"
+	"go.unistack.org/micro/v4/errors"
+	"go.unistack.org/micro/v4/metadata"
+	"go.unistack.org/micro/v4/options"
+	"go.unistack.org/micro/v4/selector"
+	"go.unistack.org/micro/v4/semconv"
+	"go.unistack.org/micro/v4/tracer"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials"
@@ -36,12 +34,10 @@ const (
 )
 
 type grpcClient struct {
-	funcPublish      client.FuncPublish
-	funcBatchPublish client.FuncBatchPublish
-	funcCall         client.FuncCall
-	funcStream       client.FuncStream
-	pool             *ConnPool
-	opts             client.Options
+	funcCall   client.FuncCall
+	funcStream client.FuncStream
+	pool       *ConnPool
+	opts       client.Options
 	sync.RWMutex
 	init bool
 }
@@ -78,15 +74,12 @@ func (g *grpcClient) secure(addr string) grpc.DialOption {
 }
 
 func (g *grpcClient) call(ctx context.Context, addr string, req client.Request, rsp interface{}, opts client.CallOptions) error {
-	var header map[string]string
+	var header map[string][]string
 
 	if md, ok := metadata.FromOutgoingContext(ctx); ok {
-		header = make(map[string]string, len(md))
-		for k, v := range md {
-			header[strings.ToLower(k)] = v
-		}
+		header = metadata.Copy(md)
 	} else {
-		header = make(map[string]string, 2)
+		header = make(map[string][]string, 2)
 	}
 	if opts.RequestMetadata != nil {
 		for k, v := range opts.RequestMetadata {
@@ -94,12 +87,11 @@ func (g *grpcClient) call(ctx context.Context, addr string, req client.Request,
 		}
 	}
 	// set timeout in nanoseconds
-	header["Grpc-Timeout"] = fmt.Sprintf("%dn", opts.RequestTimeout)
-	header["timeout"] = fmt.Sprintf("%dn", opts.RequestTimeout)
-	header["content-type"] = req.ContentType()
+	header["grpc-timeout"] = append(header["grpc-timeout"], fmt.Sprintf("%dn", opts.RequestTimeout))
+	header["timeout"] = append(header["timeout"], fmt.Sprintf("%dn", opts.RequestTimeout))
+	header["content-type"] = append(header["content-type"], req.ContentType())
 
-	md := gmetadata.New(header)
-	ctx = gmetadata.NewOutgoingContext(ctx, md)
+	ctx = gmetadata.NewOutgoingContext(ctx, header)
 
 	cf, err := g.newCodec(req.ContentType())
 	if err != nil {
@@ -185,7 +177,7 @@ func (g *grpcClient) call(ctx context.Context, addr string, req client.Request,
 	if opts.ResponseMetadata != nil {
 		*opts.ResponseMetadata = metadata.New(gmd.Len())
 		for k, v := range gmd {
-			opts.ResponseMetadata.Set(k, strings.Join(v, ","))
+			opts.ResponseMetadata.Append(k, v...)
 		}
 	}
 
@@ -193,27 +185,23 @@ func (g *grpcClient) call(ctx context.Context, addr string, req client.Request,
 }
 
 func (g *grpcClient) stream(ctx context.Context, addr string, req client.Request, rsp interface{}, opts client.CallOptions) error {
-	var header map[string]string
+	var header map[string][]string
 
 	if md, ok := metadata.FromOutgoingContext(ctx); ok {
-		header = make(map[string]string, len(md))
-		for k, v := range md {
-			header[k] = v
-		}
+		header = metadata.Copy(md)
 	} else {
-		header = make(map[string]string)
+		header = make(map[string][]string)
 	}
 
 	// set timeout in nanoseconds
 	if opts.StreamTimeout > time.Duration(0) {
-		header["Grpc-Timeout"] = fmt.Sprintf("%dn", opts.StreamTimeout)
-		header["timeout"] = fmt.Sprintf("%dn", opts.StreamTimeout)
+		header["grpc-timeout"] = append(header["grpc-timeout"], fmt.Sprintf("%dn", opts.RequestTimeout))
+		header["timeout"] = append(header["timeout"], fmt.Sprintf("%dn", opts.RequestTimeout))
 	}
 	// set the content type for the request
-	header["content-type"] = req.ContentType()
+	header["content-type"] = append(header["content-type"], req.ContentType())
 
-	md := gmetadata.New(header)
-	ctx = gmetadata.NewOutgoingContext(ctx, md)
+	ctx = gmetadata.NewOutgoingContext(ctx, header)
 
 	cf, err := g.newCodec(req.ContentType())
 	if err != nil {
@@ -418,8 +406,6 @@ func (g *grpcClient) Init(opts ...client.Option) error {
 
 	g.funcCall = g.fnCall
 	g.funcStream = g.fnStream
-	g.funcPublish = g.fnPublish
-	g.funcBatchPublish = g.fnBatchPublish
 
 	g.opts.Hooks.EachPrev(func(hook options.Hook) {
 		switch h := hook.(type) {
@@ -427,12 +413,9 @@ func (g *grpcClient) Init(opts ...client.Option) error {
 			g.funcCall = h(g.funcCall)
 		case client.HookStream:
 			g.funcStream = h(g.funcStream)
-		case client.HookPublish:
-			g.funcPublish = h(g.funcPublish)
-		case client.HookBatchPublish:
-			g.funcBatchPublish = h(g.funcBatchPublish)
 		}
 	})
+	g.init = true
 
 	return nil
 }
@@ -441,10 +424,6 @@ func (g *grpcClient) Options() client.Options {
 	return g.opts
 }
 
-func (g *grpcClient) NewMessage(topic string, msg interface{}, opts ...client.MessageOption) client.Message {
-	return newGRPCEvent(topic, msg, g.opts.ContentType, opts...)
-}
-
 func (g *grpcClient) NewRequest(service, method string, req interface{}, reqOpts ...client.RequestOption) client.Request {
 	return newGRPCRequest(service, method, req, g.opts.ContentType, reqOpts...)
 }
@@ -763,84 +742,6 @@ func (g *grpcClient) fnStream(ctx context.Context, req client.Request, opts ...c
 	return nil, grr
 }
 
-func (g *grpcClient) BatchPublish(ctx context.Context, ps []client.Message, opts ...client.PublishOption) error {
-	return g.funcBatchPublish(ctx, ps, opts...)
-}
-
-func (g *grpcClient) fnBatchPublish(ctx context.Context, ps []client.Message, opts ...client.PublishOption) error {
-	return g.publish(ctx, ps, opts...)
-}
-
-func (g *grpcClient) Publish(ctx context.Context, p client.Message, opts ...client.PublishOption) error {
-	return g.funcPublish(ctx, p, opts...)
-}
-
-func (g *grpcClient) fnPublish(ctx context.Context, p client.Message, opts ...client.PublishOption) error {
-	return g.publish(ctx, []client.Message{p}, opts...)
-}
-
-func (g *grpcClient) publish(ctx context.Context, ps []client.Message, opts ...client.PublishOption) error {
-	var body []byte
-
-	options := client.NewPublishOptions(opts...)
-
-	// get proxy
-	exchange := ""
-	if v, ok := os.LookupEnv("MICRO_PROXY"); ok {
-		exchange = v
-	}
-	// get the exchange
-	if len(options.Exchange) > 0 {
-		exchange = options.Exchange
-	}
-
-	msgs := make([]*broker.Message, 0, len(ps))
-
-	omd, ok := metadata.FromOutgoingContext(ctx)
-	if !ok {
-		omd = metadata.New(2)
-	}
-
-	for _, p := range ps {
-		md := metadata.Copy(omd)
-		topic := p.Topic()
-		if len(exchange) > 0 {
-			topic = exchange
-		}
-		md.Set(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()
-
-		// passed in raw data
-		if d, ok := p.Payload().(*codec.Frame); ok {
-			body = d.Data
-		} else {
-			// use codec for payload
-			cf, err := g.newCodec(p.ContentType())
-			if err != nil {
-				return errors.InternalServerError("go.micro.client", "%+v", err)
-			}
-			// set the body
-			b, err := cf.Marshal(p.Payload())
-			if err != nil {
-				return errors.InternalServerError("go.micro.client", "%+v", err)
-			}
-			body = b
-		}
-		msgs = append(msgs, &broker.Message{Header: md, Body: body})
-	}
-
-	return g.opts.Broker.BatchPublish(ctx, msgs,
-		broker.PublishContext(options.Context),
-		broker.PublishBodyOnly(options.BodyOnly),
-	)
-}
-
 func (g *grpcClient) String() string {
 	return "grpc"
 }
@@ -920,8 +821,6 @@ func NewClient(opts ...client.Option) client.Client {
 
 	c.funcCall = c.fnCall
 	c.funcStream = c.fnStream
-	c.funcPublish = c.fnPublish
-	c.funcBatchPublish = c.fnBatchPublish
 
 	return c
 }
diff --git a/message.go b/message.go
deleted file mode 100644
index f511f46..0000000
--- a/message.go
+++ /dev/null
@@ -1,44 +0,0 @@
-package grpc
-
-import (
-	"go.unistack.org/micro/v3/client"
-	"go.unistack.org/micro/v3/metadata"
-)
-
-type grpcEvent struct {
-	payload     interface{}
-	topic       string
-	contentType string
-	opts        client.MessageOptions
-}
-
-func newGRPCEvent(topic string, payload interface{}, contentType string, opts ...client.MessageOption) client.Message {
-	options := client.NewMessageOptions(opts...)
-
-	if len(options.ContentType) > 0 {
-		contentType = options.ContentType
-	}
-
-	return &grpcEvent{
-		payload:     payload,
-		topic:       topic,
-		contentType: contentType,
-		opts:        options,
-	}
-}
-
-func (g *grpcEvent) ContentType() string {
-	return g.contentType
-}
-
-func (g *grpcEvent) Topic() string {
-	return g.topic
-}
-
-func (g *grpcEvent) Payload() interface{} {
-	return g.payload
-}
-
-func (g *grpcEvent) Metadata() metadata.Metadata {
-	return g.opts.Metadata
-}
diff --git a/options.go b/options.go
index 02e56a8..f5ea9ec 100644
--- a/options.go
+++ b/options.go
@@ -4,7 +4,7 @@ package grpc
 import (
 	"context"
 
-	"go.unistack.org/micro/v3/client"
+	"go.unistack.org/micro/v4/client"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/encoding"
 )
diff --git a/request.go b/request.go
index a0f808e..2450aee 100644
--- a/request.go
+++ b/request.go
@@ -4,8 +4,8 @@ import (
 	"fmt"
 	"strings"
 
-	"go.unistack.org/micro/v3/client"
-	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v4/client"
+	"go.unistack.org/micro/v4/codec"
 )
 
 type grpcRequest struct {
diff --git a/response.go b/response.go
index 6c449cb..6ed854e 100644
--- a/response.go
+++ b/response.go
@@ -1,10 +1,8 @@
 package grpc
 
 import (
-	"strings"
-
-	"go.unistack.org/micro/v3/codec"
-	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v4/codec"
+	"go.unistack.org/micro/v4/metadata"
 	"google.golang.org/grpc"
 )
 
@@ -25,14 +23,19 @@ func (r *response) Header() metadata.Metadata {
 	if err != nil {
 		return nil
 	}
-	md := metadata.New(len(meta))
-	for k, v := range meta {
-		md.Set(k, strings.Join(v, ","))
-	}
-	return md
+
+	return metadata.Metadata(meta.Copy())
 }
 
 // Read the undecoded response
 func (r *response) Read() ([]byte, error) {
-	return nil, nil
+	f := &codec.Frame{}
+	wrap := &wrapStream{r.stream}
+
+	_, err := wrap.Read(f.Data)
+	if err != nil {
+		return nil, err
+	}
+
+	return f.Data, nil
 }
diff --git a/stream.go b/stream.go
index 00cf622..b591017 100644
--- a/stream.go
+++ b/stream.go
@@ -5,8 +5,8 @@ import (
 	"io"
 	"sync"
 
-	"go.unistack.org/micro/v3/client"
-	"go.unistack.org/micro/v3/tracer"
+	"go.unistack.org/micro/v4/client"
+	"go.unistack.org/micro/v4/tracer"
 	"google.golang.org/grpc"
 )