diff --git a/codec/codec.go b/codec/codec.go
index c41cfaa9..8277cf51 100644
--- a/codec/codec.go
+++ b/codec/codec.go
@@ -23,13 +23,21 @@ type NewCodec func(io.ReadWriteCloser) Codec
 // connection. ReadBody may be called with a nil argument to force the
 // body to be read and discarded.
 type Codec interface {
-	ReadHeader(*Message, MessageType) error
-	ReadBody(interface{}) error
-	Write(*Message, interface{}) error
+	Reader
+	Writer
 	Close() error
 	String() string
 }
 
+type Reader interface {
+	ReadHeader(*Message, MessageType) error
+	ReadBody(interface{}) error
+}
+
+type Writer interface {
+	Write(*Message, interface{}) error
+}
+
 // Message represents detailed information about
 // the communication, likely followed by the body.
 // In the case of an error, body may be nil.
@@ -42,5 +50,5 @@ type Message struct {
 
 	// The values read from the socket
 	Header map[string]string
-	Body []byte
+	Body   []byte
 }
diff --git a/server/rpc_request.go b/server/rpc_request.go
index 31e2bb80..cbc4179d 100644
--- a/server/rpc_request.go
+++ b/server/rpc_request.go
@@ -22,7 +22,7 @@ type rpcMessage struct {
 	payload     interface{}
 }
 
-func (r *rpcRequest) Codec() codec.Codec {
+func (r *rpcRequest) Codec() codec.Reader {
 	return r.codec
 }
 
diff --git a/server/rpc_response.go b/server/rpc_response.go
index 92f974a1..d89fa0b6 100644
--- a/server/rpc_response.go
+++ b/server/rpc_response.go
@@ -3,12 +3,18 @@ package server
 import (
 	"net/http"
 
+	"github.com/micro/go-micro/codec"
 	"github.com/micro/go-micro/transport"
 )
 
 type rpcResponse struct {
 	header map[string]string
 	socket transport.Socket
+	codec  codec.Codec
+}
+
+func (r *rpcResponse) Codec() codec.Writer {
+	return r.codec
 }
 
 func (r *rpcResponse) WriteHeader(hdr map[string]string) {
diff --git a/server/rpc_router.go b/server/rpc_router.go
index 67db4f20..1043036b 100644
--- a/server/rpc_router.go
+++ b/server/rpc_router.go
@@ -164,7 +164,7 @@ func prepareMethod(method reflect.Method) *methodType {
 	return &methodType{method: method, ArgType: argType, ReplyType: replyType, ContextType: contextType, stream: stream}
 }
 
-func (router *router) sendResponse(sending sync.Locker, req *request, reply interface{}, cc codec.Codec, errmsg string, last bool) (err error) {
+func (router *router) sendResponse(sending sync.Locker, req *request, reply interface{}, cc codec.Writer, errmsg string, last bool) (err error) {
 	msg := new(codec.Message)
 	msg.Type = codec.Response
 	resp := router.getResponse()
@@ -184,7 +184,7 @@ func (router *router) sendResponse(sending sync.Locker, req *request, reply inte
 	return err
 }
 
-func (s *service) call(ctx context.Context, router *router, sending *sync.Mutex, mtype *methodType, req *request, argv, replyv reflect.Value, cc codec.Codec) {
+func (s *service) call(ctx context.Context, router *router, sending *sync.Mutex, mtype *methodType, req *request, argv, replyv reflect.Value, cc codec.Writer) {
 	function := mtype.method.Func
 	var returnValues []reflect.Value
 
@@ -232,7 +232,7 @@ func (s *service) call(ctx context.Context, router *router, sending *sync.Mutex,
 
 	stream := &rpcStream{
 		context: ctx,
-		codec:   cc,
+		codec:   cc.(codec.Codec),
 		request: r,
 		id:      req.msg.Id,
 	}
@@ -358,7 +358,7 @@ func (router *router) readRequest(r Request) (service *service, mtype *methodTyp
 	return
 }
 
-func (router *router) readHeader(cc codec.Codec) (service *service, mtype *methodType, req *request, keepReading bool, err error) {
+func (router *router) readHeader(cc codec.Reader) (service *service, mtype *methodType, req *request, keepReading bool, err error) {
 	// Grab the request header.
 	msg := new(codec.Message)
 	msg.Type = codec.Request
@@ -449,7 +449,6 @@ func (router *router) Handle(h Handler) error {
 }
 
 func (router *router) ServeRequest(ctx context.Context, r Request, rsp Response) error {
-	cc := r.Codec()
 	sending := new(sync.Mutex)
 	service, mtype, req, argv, replyv, keepReading, err := router.readRequest(r)
 	if err != nil {
@@ -458,11 +457,11 @@ func (router *router) ServeRequest(ctx context.Context, r Request, rsp Response)
 		}
 		// send a response if we actually managed to read a header.
 		if req != nil {
-			router.sendResponse(sending, req, invalidRequest, cc, err.Error(), true)
+			router.sendResponse(sending, req, invalidRequest, rsp.Codec(), err.Error(), true)
 			router.freeRequest(req)
 		}
 		return err
 	}
-	service.call(ctx, router, sending, mtype, req, argv, replyv, cc)
+	service.call(ctx, router, sending, mtype, req, argv, replyv, rsp.Codec())
 	return nil
 }
diff --git a/server/rpc_server.go b/server/rpc_server.go
index 1fc445a6..4481d9bb 100644
--- a/server/rpc_server.go
+++ b/server/rpc_server.go
@@ -110,12 +110,14 @@ func (s *rpcServer) ServeConn(sock transport.Socket) {
 			return
 		}
 
+		codec := newRpcCodec(&msg, sock, cf)
+
 		// internal request
 		request := &rpcRequest{
 			service:     msg.Header["X-Micro-Service"],
 			method:      msg.Header["X-Micro-Method"],
 			contentType: ct,
-			codec:       newRpcCodec(&msg, sock, cf),
+			codec:       codec,
 			header:      msg.Header,
 			body:        msg.Body,
 			socket:      sock,
@@ -126,6 +128,7 @@ func (s *rpcServer) ServeConn(sock transport.Socket) {
 		response := &rpcResponse{
 			header: make(map[string]string),
 			socket: sock,
+			codec:  codec,
 		}
 
 		// set router
diff --git a/server/server.go b/server/server.go
index 4b390f0a..fbfacd0d 100644
--- a/server/server.go
+++ b/server/server.go
@@ -54,13 +54,15 @@ type Request interface {
 	// Read the undecoded request body
 	Read() ([]byte, error)
 	// The encoded message stream
-	Codec() codec.Codec
+	Codec() codec.Reader
 	// Indicates whether its a stream
 	Stream() bool
 }
 
 // Response is the response writer for unencoded messages
 type Response interface {
+	// Encoded writer
+	Codec() codec.Writer
 	// Write the header
 	WriteHeader(map[string]string)
 	// write a response directly to the client