diff --git a/example/main.go b/example/main.go
index 8dd4a8a..5707641 100644
--- a/example/main.go
+++ b/example/main.go
@@ -5,8 +5,9 @@ import (
 	"flag"
 	"fmt"
 	"git.diulo.com/mogfee/kit"
+	"git.diulo.com/mogfee/kit/errors"
+	"git.diulo.com/mogfee/kit/middleware/cors"
 	"git.diulo.com/mogfee/kit/transport/http"
-	http2 "net/http"
 )
 
 var host string
@@ -15,20 +16,6 @@ func init() {
 	flag.StringVar(&host, "h", "localhost:9922", "")
 }
 
-type cros struct {
-	h http2.Handler
-}
-
-func (c *cros) ServeHTTP(writer http2.ResponseWriter, request *http2.Request) {
-	request.Header.Set("Access-Control-Allow-Origin", "*")
-	request.Header.Set("Access-Control-Allow-Methods", "GET,POST,OPTIONS,PUT,PATCH,DELETE")
-	request.Header.Set("Access-Control-Allow-Credentials", "true")
-	request.Header.Set("Access-Control-Allow-Headers", "Content-Type,X-Requested-With,Access-Control-Allow-Credentials,User-Agent,Content-Length,Authorization")
-	request.Header.Set("xxxxx", "11")
-	fmt.Println("xxx")
-	c.h.ServeHTTP(writer, request)
-}
-
 func main() {
 	flag.Parse()
 	runApp(host)
@@ -47,15 +34,16 @@ func runApp(host string) {
 		//		h: handler,
 		//	}
 		//}),
-		http.Middleware(),
+		http.Middleware(cors.Cors()),
 	)
 	route := hs.Route("/")
-	route.GET("/api/v1/answer/listCategory", func(ctx http.Context) error {
+	route.POST("/api/v1/answer/addQuestion", func(ctx http.Context) error {
 		in := UserAddRequest{Name: "tom"}
 		http.SetOperation(ctx, "/api/abc")
 		h := ctx.Middleware(func(ctx context.Context, a any) (any, error) {
 			//tr, _ := transport.FromServerContext(ctx)
-			return AddUser(ctx, a.(*UserAddRequest))
+			//return AddUser(ctx, a.(*UserAddRequest))
+			return nil, errors.New(400, "BAD", "a")
 		})
 		out, err := h(ctx, &in)
 		if err != nil {
diff --git a/transport/http/codec.go b/transport/http/codec.go
index cb0e25d..aa47131 100644
--- a/transport/http/codec.go
+++ b/transport/http/codec.go
@@ -73,6 +73,7 @@ func DefaultResponseEncoder(w http.ResponseWriter, r *http.Request, v any) error
 	return err
 }
 func DefaultErrorEncoder(w http.ResponseWriter, r *http.Request, err error) {
+	fmt.Printf("%+v\n", w.Header())
 	se := errors.FromError(err)
 	codec, _ := CodeForRequest(r, "Accept")
 	body, err := codec.Marshal(se)
@@ -81,12 +82,6 @@ func DefaultErrorEncoder(w http.ResponseWriter, r *http.Request, err error) {
 		return
 	}
 	w.Header().Set("Content-Type", httputil.ContentType(codec.Name()))
-
-	//w.Header().Set("Access-Control-Allow-Origin", "*")
-	//w.Header().Set("Access-Control-Allow-Methods", "GET,POST,OPTIONS,PUT,PATCH,DELETE")
-	//w.Header().Set("Access-Control-Allow-Credentials", "true")
-	//w.Header().Set("Access-Control-Allow-Headers", "Content-Type,X-Requested-With,Access-Control-Allow-Credentials,User-Agent,Content-Length,Authorization")
-
 	w.WriteHeader(int(se.Status.Code))
 	_, _ = w.Write(body)
 }
diff --git a/transport/http/server.go b/transport/http/server.go
index d073c6d..75c68d7 100644
--- a/transport/http/server.go
+++ b/transport/http/server.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"crypto/tls"
 	"errors"
+	"fmt"
 	"git.diulo.com/mogfee/kit/internal/endpoint"
 	"git.diulo.com/mogfee/kit/internal/host"
 	"git.diulo.com/mogfee/kit/internal/matcher"
@@ -306,6 +307,7 @@ func (s *Server) filter() mux.MiddlewareFunc {
 			if s.endpoint != nil {
 				tr.endpoint = s.endpoint.String()
 			}
+			fmt.Println("tr")
 			tr.request = req.WithContext(transport.NewServerContext(ctx, tr))
 			next.ServeHTTP(w, tr.request)
 		})