diff --git a/gateway/handle.go b/gateway/handle.go
index 5312efd..6ec4390 100644
--- a/gateway/handle.go
+++ b/gateway/handle.go
@@ -9,7 +9,7 @@ import (
 
 func Handle(sh ServerHandler, codec protocol.ServerCodec, r io.Reader, w io.Writer) error {
 	return rpc.Handle(sh, codec, r, w, func(codecReq protocol.ServerCodecRequest) (result interface{}, err error) {
-		var params []byte
+		var params []string
 		if params, err = codecReq.Params(); nil != err {
 			return nil, err
 		}
diff --git a/gateway/server_handler.go b/gateway/server_handler.go
index 890ff70..88178f3 100644
--- a/gateway/server_handler.go
+++ b/gateway/server_handler.go
@@ -7,5 +7,5 @@ import (
 type ServerHandler interface {
 	rpc.ServerHandler
 
-	Invoke(method string, params []byte) (result interface{}, err error)
+	Invoke(method string, params []string) (result interface{}, err error)
 }
diff --git a/gateway/server_handlers.go b/gateway/server_handlers.go
index e695155..7f822f4 100644
--- a/gateway/server_handlers.go
+++ b/gateway/server_handlers.go
@@ -10,7 +10,7 @@ type ServerHandlers struct {
 	rpc.ServerHandlers
 }
 
-func (sh *ServerHandlers) Invoke(method string, params []byte) (result interface{}, err error) {
+func (sh *ServerHandlers) Invoke(method string, params []string) (result interface{}, err error) {
 
 	return nil, errors.New("Server: Handler method[Invoke] of Server is not implement")
 }
diff --git a/protocol/json/client_notify.go b/protocol/json/client_notify.go
index 1f40d16..a7a057d 100644
--- a/protocol/json/client_notify.go
+++ b/protocol/json/client_notify.go
@@ -62,9 +62,20 @@ func (ccn *ClientCodecNotify) ReadParams(args []interface{}) error {
 	return ccn.err
 }
 
-func (ccn *ClientCodecNotify) Params() ([]byte, error) {
+func (ccn *ClientCodecNotify) Params() ([]string, error) {
 	if ccn.err == nil && ccn.notify.Params != nil {
-		return *ccn.notify.Params, nil
+		var results []string
+
+		if err := json.Unmarshal(*ccn.notify.Params, &results); err != nil {
+			ccn.err = &Error{
+				Code:    E_INVALID_REQ,
+				Message: err.Error(),
+				Data:    ccn.notify.Params,
+			}
+			return nil, ccn.err
+		}
+
+		return results, nil
 	}
 	return nil, ccn.err
 }
diff --git a/protocol/json/server.go b/protocol/json/server.go
index 7ad57c2..6f8f53b 100644
--- a/protocol/json/server.go
+++ b/protocol/json/server.go
@@ -202,9 +202,20 @@ func (scr *ServerCodecRequest) ReadParams(args []interface{}) error {
 	return scr.err
 }
 
-func (scr *ServerCodecRequest) Params() ([]byte, error) {
+func (scr *ServerCodecRequest) Params() ([]string, error) {
 	if scr.err == nil && scr.request.Params != nil {
-		return *scr.request.Params, nil
+		var results []string
+
+		if err := json.Unmarshal(*scr.request.Params, &results); err != nil {
+			scr.err = &Error{
+				Code:    E_INVALID_REQ,
+				Message: err.Error(),
+				Data:    scr.request.Params,
+			}
+			return nil, scr.err
+		}
+
+		return results, nil
 	}
 	return nil, scr.err
 }
diff --git a/protocol/registry_codec.go b/protocol/registry_codec.go
index 421cd21..44babe7 100644
--- a/protocol/registry_codec.go
+++ b/protocol/registry_codec.go
@@ -9,6 +9,6 @@ type RegistryCodec interface {
 	Method() string
 	// Reads the request filling the RPC method args.
 	ReadParams(args []interface{}) error
-	Params() ([]byte, error)
+	Params() ([]string, error)
 	Complete()
 }
diff --git a/server_handler.go b/server_handler.go
index 855ea7e..c228a73 100644
--- a/server_handler.go
+++ b/server_handler.go
@@ -8,6 +8,7 @@ import (
 
 type ServerHandler interface {
 	RegisterCodec(codec protocol.ServerCodec, contentType string)
+	GetCodec(contentType string) (protocol.ServerCodec, error)
 
 	OnPreRead(r io.Reader)
 	OnPostRead(r io.Reader)
@@ -17,6 +18,4 @@ type ServerHandler interface {
 
 	OnPreWriteError(w io.Writer, err error)
 	OnPostWriteError(w io.Writer, err error)
-
-	GetCodec(contentType string) (protocol.ServerCodec, error)
 }