diff --git a/go.mod b/go.mod
index e2643ca..647abd7 100644
--- a/go.mod
+++ b/go.mod
@@ -5,7 +5,7 @@ go 1.23.1
 require (
 	somehole.com/common/log v0.1.3
 	somehole.com/common/security v0.2.1
-	somehole.com/service/router v0.13.3
+	somehole.com/service/router v0.16.0
 )
 
 require (
diff --git a/go.sum b/go.sum
index 25ece5b..ea17284 100644
--- a/go.sum
+++ b/go.sum
@@ -8,5 +8,5 @@ somehole.com/common/log v0.1.3 h1:2PAui0+5EryTAHqVUZQeepLcJTGssHKz2OL+jBknHI0=
 somehole.com/common/log v0.1.3/go.mod h1:NS2eHnN120GA6oFbBm3XhB5yHww0eXTbLuMQYZxYNyA=
 somehole.com/common/security v0.2.1 h1:H7TpErYKsCOxKYYie75jU7azO5vEgeqrQ9uA+AjXafA=
 somehole.com/common/security v0.2.1/go.mod h1:6SMKdIrfxT460XXWafpD6A9yT/ykwipGsGztA5g5vVM=
-somehole.com/service/router v0.13.3 h1:q4jGnqMIB+o78ZUmKy9HVMFpO/fjRh6Wud3WGIMH1rM=
-somehole.com/service/router v0.13.3/go.mod h1:F+/sNY4/ei7C9QD5+iA+gUHugcOAcrWspHKwX8d8oiM=
+somehole.com/service/router v0.16.0 h1:h9swbPfyCmXej26nvoXZYIt3RT/sAZPQZnCz1rbLBQk=
+somehole.com/service/router v0.16.0/go.mod h1:F+/sNY4/ei7C9QD5+iA+gUHugcOAcrWspHKwX8d8oiM=
diff --git a/router.go b/router.go
index 0e9f825..f4383ad 100644
--- a/router.go
+++ b/router.go
@@ -1,8 +1,6 @@
 package oauth2
 
 import (
-	"fmt"
-
 	"somehole.com/common/log"
 	"somehole.com/service/oauth2/server"
 	"somehole.com/service/router"
@@ -46,27 +44,9 @@ func NewRouter(r *router.Router, logger log.Logger, optionalEndpoints ...Endpoin
 }
 
 func (ro *Router) RegisterCallbackServer(srv server.CallbackServer) {
-	pro := router.Prototype{PrototypeRequestBuilder: server.CallbackRequestBuilder{}, PrototypeResponse: server.CallbackResponse{}}
-	server := func(req router.RequestBuilder, res router.Response) (errRes router.ErrorResponse) {
-		callbackRequest, ok := req.(*server.CallbackRequestBuilder)
-		if !ok {
-			panic(fmt.Errorf("expected CallbackRequest, got %T", req))
-		}
-		res, errRes = srv.Callback(callbackRequest)
-		return
-	}
-	ro.Register(ro.CallbackEndpoint, router.NewServer(pro, ro.Logger, server))
+	ro.Register(ro.CallbackEndpoint, router.NewServer(&server.CallbackRequestBuilder{}, &server.CallbackResponse{}, ro.Logger, srv.Callback))
 }
 
 func (ro *Router) RegisterTokenServer(srv server.TokenServer) {
-	pro := router.Prototype{PrototypeRequestBuilder: server.TokenRequestBuilder{}, PrototypeResponse: server.TokenResponse{}}
-	server := func(req router.RequestBuilder, res router.Response) (errRes router.ErrorResponse) {
-		callbackRequest, ok := req.(*server.TokenRequestBuilder)
-		if !ok {
-			panic(fmt.Errorf("expected TokenRequest, got %T", req))
-		}
-		res, errRes = srv.Token(callbackRequest)
-		return
-	}
-	ro.Register(ro.TokenEndpoint, router.NewServer(pro, ro.Logger, server))
+	ro.Register(ro.TokenEndpoint, router.NewServer(&server.TokenRequestBuilder{}, &server.TokenResponse{}, ro.Logger, srv.Token))
 }
diff --git a/server/callback.go b/server/callback.go
index 57b1e02..af1b475 100644
--- a/server/callback.go
+++ b/server/callback.go
@@ -15,7 +15,7 @@ type CallbackRequestBuilder struct {
 }
 
 func (rb CallbackRequestBuilder) RequestBuilder() router.RequestBuilder {
-	rb.DefaultRequestBuilder = router.NewDefaultRequestBuilder(&rb, nil, nil, nil, &rb.values.Values, &rb.values, nil, nil)
+	rb.DefaultRequestBuilder = router.NewDefaultRequestBuilder(&rb, CallbackRequestBuilder{}, &ErrorHandler{}, nil, nil, nil, &rb.values.Values, &rb.values, nil, nil)
 	return &rb
 }
 
@@ -28,7 +28,7 @@ type CallbackResponse struct {
 }
 
 func (r CallbackResponse) Response() router.Response {
-	r.DefaultResponse = router.NewDefaultResponse(&r, nil, nil, &r.Body.Body, &r.Body)
+	r.DefaultResponse = router.NewDefaultResponse(&r, CallbackResponse{}, nil, nil, &r.Body.Body, &r.Body)
 	return &r
 }
 
@@ -37,7 +37,7 @@ type UnimplementedCallbackServer struct{}
 func (UnimplementedCallbackServer) mustEmbedUnimplementedCallbackServer() {}
 
 func (UnimplementedCallbackServer) Callback(req *CallbackRequestBuilder) (res *CallbackResponse, errRes router.ErrorResponse) {
-	errRes = ErrorNotImplemented
+	errRes = &ErrorHandler{router.DefaultErrorNotImplemented}
 	return
 }
 
diff --git a/server/error.go b/server/error.go
index ad17457..a53d19a 100644
--- a/server/error.go
+++ b/server/error.go
@@ -2,54 +2,19 @@ package server
 
 import (
 	"encoding/json"
-	"fmt"
-	"net/http"
+
+	"somehole.com/service/router"
 )
 
-type Error uint32
-
-const (
-	Ok                    Error = http.StatusOK
-	ErrorNotImplemented   Error = http.StatusNotImplemented
-	ErrorMethodNotAllowed Error = http.StatusMethodNotAllowed
-	ErrorBadRequest       Error = http.StatusBadRequest
-	ErrorUnauthorized     Error = http.StatusUnauthorized
-	ErrorServerError      Error = http.StatusInternalServerError
-)
-
-func (e Error) Ok() (ok bool) {
-	return e == Ok
+type ErrorHandler struct {
+	router.DefaultError
 }
 
-func (e Error) HttpStatus() (code int) {
-	return int(e)
+func (*ErrorHandler) ErrorResponse(errorResponse router.ErrorResponse) router.ErrorResponse {
+	return &ErrorHandler{errorResponse.(router.DefaultError)}
 }
 
-func (e Error) String() (out string) {
-	switch e {
-	case Ok:
-		out = "ok"
-	case ErrorNotImplemented:
-		out = "server not implemented"
-	case ErrorMethodNotAllowed:
-		out = "method not allowed"
-	case ErrorBadRequest:
-		out = "bad request"
-	case ErrorUnauthorized:
-		out = "user unauthorized"
-	case ErrorServerError:
-		out = "internal server error"
-	default:
-		out = "unhandled error"
-	}
-	return
-}
-
-func (e Error) Error() (out string) {
-	return fmt.Sprintf("%s (%d)", e.String(), e.HttpStatus())
-}
-
-func (e Error) BodyBytes() (body []byte) {
+func (e *ErrorHandler) BodyBytes() (body []byte) {
 	body, _ = json.Marshal(struct{ Error string }{Error: e.String()})
 	return
 }
diff --git a/server/token.go b/server/token.go
index cb7703f..3239baa 100644
--- a/server/token.go
+++ b/server/token.go
@@ -16,7 +16,7 @@ type TokenRequestBuilder struct {
 }
 
 func (rb TokenRequestBuilder) RequestBuilder() router.RequestBuilder {
-	rb.DefaultRequestBuilder = router.NewDefaultRequestBuilder(&rb, nil, nil, nil, &rb.values.Values, &rb.values, nil, nil)
+	rb.DefaultRequestBuilder = router.NewDefaultRequestBuilder(&rb, TokenRequestBuilder{}, &ErrorHandler{}, nil, nil, nil, &rb.values.Values, &rb.values, nil, nil)
 	return &rb
 }
 
@@ -33,7 +33,7 @@ type TokenResponse struct {
 }
 
 func (r TokenResponse) Response() router.Response {
-	r.DefaultResponse = router.NewDefaultResponse(&r, nil, nil, &r.Body.Body, &r.Body)
+	r.DefaultResponse = router.NewDefaultResponse(&r, TokenResponse{}, nil, nil, &r.Body.Body, &r.Body)
 	return &r
 }
 
@@ -42,7 +42,7 @@ type UnimplementedTokenServer struct{}
 func (UnimplementedTokenServer) mustEmbedUnimplementedTokenServer() {}
 
 func (UnimplementedTokenServer) Token(req *TokenRequestBuilder) (res *TokenResponse, errRes router.ErrorResponse) {
-	errRes = ErrorNotImplemented
+	errRes = &ErrorHandler{router.DefaultErrorNotImplemented}
 	return
 }