diff --git a/README.md b/README.md
index 9ef3dd9..feb66b3 100644
--- a/README.md
+++ b/README.md
@@ -17,6 +17,7 @@ Features:
     - [ ] mdns
     - [ ] kubernetes
 - [ ] default interceptors implementation: 
+    - [ ] default
     - [ ] validation
     - [ ] health
     - [ ] context logger
@@ -24,8 +25,8 @@ Features:
     - [ ] rate-limiting
     - [ ] auth claim in context
     - [ ] recovery
-    - [ ] tracing (open-tracing)
-    - [ ] metrics (prometheus)
+    - [x] tracing (open-tracing)
+    - [x] metrics (prometheus)
     - [ ] retries
     - [ ] context DB / transaction
     - ...
diff --git a/example/example.go b/example/example.go
index 1b05f4b..87ab274 100644
--- a/example/example.go
+++ b/example/example.go
@@ -14,6 +14,8 @@ import (
 	"github.com/sirupsen/logrus"
 
 	"go.linka.cloud/grpc/client"
+	metrics2 "go.linka.cloud/grpc/interceptors/metrics"
+	validation2 "go.linka.cloud/grpc/interceptors/validation"
 	"go.linka.cloud/grpc/logger"
 	"go.linka.cloud/grpc/registry/mdns"
 	"go.linka.cloud/grpc/service"
@@ -32,6 +34,7 @@ func (g *GreeterHandler) SayHello(ctx context.Context, req *HelloRequest) (*Hell
 }
 
 func (g *GreeterHandler) SayHelloStream(req *HelloStreamRequest, s Greeter_SayHelloStreamServer) error {
+
 	for i := int64(0); i < req.Count; i++ {
 		if err := s.Send(&HelloReply{Message: fmt.Sprintf("Hello %s (%d)!", req.Name, i+1)}); err != nil {
 			return err
@@ -64,6 +67,8 @@ func main() {
 	defer cancel()
 	var svc service.Service
 	var err error
+	metrics := metrics2.NewInterceptors()
+	validation := validation2.NewInterceptors(true)
 	address := "0.0.0.0:9991"
 	svc, err = service.New(
 		service.WithContext(ctx),
@@ -88,6 +93,7 @@ func main() {
 		service.WithGRPCWeb(true),
 		service.WithGRPCWebPrefix("/grpc"),
 		service.WithMiddlewares(httpLogger),
+		service.WithInterceptors(validation, metrics),
 	)
 	if err != nil {
 		panic(err)
@@ -115,6 +121,10 @@ func main() {
 		logrus.Fatal(err)
 	}
 	logrus.Infof("received message: %s", res.Message)
+	res, err = g.SayHello(context.Background(), &HelloRequest{})
+	if err == nil {
+		logrus.Fatal("expected validation error")
+	}
 	stream, err := g.SayHelloStream(context.Background(), &HelloStreamRequest{Name: "test", Count: 10})
 	if err != nil {
 		logrus.Fatal(err)
diff --git a/example/example.pb.go b/example/example.pb.go
index 41e7fa0..70a797f 100644
--- a/example/example.pb.go
+++ b/example/example.pb.go
@@ -10,6 +10,7 @@ import (
 	reflect "reflect"
 	sync "sync"
 
+	_ "github.com/envoyproxy/protoc-gen-validate/validate"
 	_ "google.golang.org/genproto/googleapis/api/annotations"
 	protoreflect "google.golang.org/protobuf/reflect/protoreflect"
 	protoimpl "google.golang.org/protobuf/runtime/protoimpl"
@@ -178,30 +179,33 @@ var file_example_example_proto_rawDesc = []byte{
 	0x65, 0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x12, 0x0a, 0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x77, 0x6f,
 	0x72, 0x6c, 0x64, 0x1a, 0x1c, 0x67, 0x6f, 0x6f, 0x67, 0x6c, 0x65, 0x2f, 0x61, 0x70, 0x69, 0x2f,
 	0x61, 0x6e, 0x6e, 0x6f, 0x74, 0x61, 0x74, 0x69, 0x6f, 0x6e, 0x73, 0x2e, 0x70, 0x72, 0x6f, 0x74,
-	0x6f, 0x22, 0x22, 0x0a, 0x0c, 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x52, 0x65, 0x71, 0x75, 0x65, 0x73,
-	0x74, 0x12, 0x12, 0x0a, 0x04, 0x6e, 0x61, 0x6d, 0x65, 0x18, 0x01, 0x20, 0x01, 0x28, 0x09, 0x52,
-	0x04, 0x6e, 0x61, 0x6d, 0x65, 0x22, 0x26, 0x0a, 0x0a, 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x52, 0x65,
-	0x70, 0x6c, 0x79, 0x12, 0x18, 0x0a, 0x07, 0x6d, 0x65, 0x73, 0x73, 0x61, 0x67, 0x65, 0x18, 0x01,
-	0x20, 0x01, 0x28, 0x09, 0x52, 0x07, 0x6d, 0x65, 0x73, 0x73, 0x61, 0x67, 0x65, 0x22, 0x3e, 0x0a,
-	0x12, 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x53, 0x74, 0x72, 0x65, 0x61, 0x6d, 0x52, 0x65, 0x71, 0x75,
-	0x65, 0x73, 0x74, 0x12, 0x12, 0x0a, 0x04, 0x6e, 0x61, 0x6d, 0x65, 0x18, 0x01, 0x20, 0x01, 0x28,
-	0x09, 0x52, 0x04, 0x6e, 0x61, 0x6d, 0x65, 0x12, 0x14, 0x0a, 0x05, 0x63, 0x6f, 0x75, 0x6e, 0x74,
-	0x18, 0x02, 0x20, 0x01, 0x28, 0x03, 0x52, 0x05, 0x63, 0x6f, 0x75, 0x6e, 0x74, 0x32, 0xb7, 0x01,
-	0x0a, 0x07, 0x47, 0x72, 0x65, 0x65, 0x74, 0x65, 0x72, 0x12, 0x5e, 0x0a, 0x08, 0x53, 0x61, 0x79,
-	0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x12, 0x18, 0x2e, 0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x77, 0x6f, 0x72,
-	0x6c, 0x64, 0x2e, 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x52, 0x65, 0x71, 0x75, 0x65, 0x73, 0x74, 0x1a,
-	0x16, 0x2e, 0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x77, 0x6f, 0x72, 0x6c, 0x64, 0x2e, 0x48, 0x65, 0x6c,
-	0x6c, 0x6f, 0x52, 0x65, 0x70, 0x6c, 0x79, 0x22, 0x20, 0x82, 0xd3, 0xe4, 0x93, 0x02, 0x1a, 0x22,
-	0x15, 0x2f, 0x61, 0x70, 0x69, 0x2f, 0x76, 0x31, 0x2f, 0x67, 0x72, 0x65, 0x65, 0x74, 0x65, 0x72,
-	0x2f, 0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x3a, 0x01, 0x2a, 0x12, 0x4c, 0x0a, 0x0e, 0x53, 0x61, 0x79,
-	0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x53, 0x74, 0x72, 0x65, 0x61, 0x6d, 0x12, 0x1e, 0x2e, 0x68, 0x65,
-	0x6c, 0x6c, 0x6f, 0x77, 0x6f, 0x72, 0x6c, 0x64, 0x2e, 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x53, 0x74,
-	0x72, 0x65, 0x61, 0x6d, 0x52, 0x65, 0x71, 0x75, 0x65, 0x73, 0x74, 0x1a, 0x16, 0x2e, 0x68, 0x65,
-	0x6c, 0x6c, 0x6f, 0x77, 0x6f, 0x72, 0x6c, 0x64, 0x2e, 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x52, 0x65,
-	0x70, 0x6c, 0x79, 0x22, 0x00, 0x30, 0x01, 0x42, 0x22, 0x5a, 0x20, 0x67, 0x6f, 0x2e, 0x6c, 0x69,
-	0x6e, 0x6b, 0x61, 0x2e, 0x63, 0x6c, 0x6f, 0x75, 0x64, 0x2f, 0x67, 0x72, 0x70, 0x63, 0x2f, 0x65,
-	0x78, 0x61, 0x6d, 0x70, 0x6c, 0x65, 0x3b, 0x6d, 0x61, 0x69, 0x6e, 0x62, 0x06, 0x70, 0x72, 0x6f,
-	0x74, 0x6f, 0x33,
+	0x6f, 0x1a, 0x17, 0x76, 0x61, 0x6c, 0x69, 0x64, 0x61, 0x74, 0x65, 0x2f, 0x76, 0x61, 0x6c, 0x69,
+	0x64, 0x61, 0x74, 0x65, 0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x22, 0x2d, 0x0a, 0x0c, 0x48, 0x65,
+	0x6c, 0x6c, 0x6f, 0x52, 0x65, 0x71, 0x75, 0x65, 0x73, 0x74, 0x12, 0x1d, 0x0a, 0x04, 0x6e, 0x61,
+	0x6d, 0x65, 0x18, 0x01, 0x20, 0x01, 0x28, 0x09, 0x42, 0x09, 0xfa, 0x42, 0x06, 0x72, 0x04, 0x10,
+	0x02, 0x18, 0x28, 0x52, 0x04, 0x6e, 0x61, 0x6d, 0x65, 0x22, 0x26, 0x0a, 0x0a, 0x48, 0x65, 0x6c,
+	0x6c, 0x6f, 0x52, 0x65, 0x70, 0x6c, 0x79, 0x12, 0x18, 0x0a, 0x07, 0x6d, 0x65, 0x73, 0x73, 0x61,
+	0x67, 0x65, 0x18, 0x01, 0x20, 0x01, 0x28, 0x09, 0x52, 0x07, 0x6d, 0x65, 0x73, 0x73, 0x61, 0x67,
+	0x65, 0x22, 0x49, 0x0a, 0x12, 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x53, 0x74, 0x72, 0x65, 0x61, 0x6d,
+	0x52, 0x65, 0x71, 0x75, 0x65, 0x73, 0x74, 0x12, 0x1d, 0x0a, 0x04, 0x6e, 0x61, 0x6d, 0x65, 0x18,
+	0x01, 0x20, 0x01, 0x28, 0x09, 0x42, 0x09, 0xfa, 0x42, 0x06, 0x72, 0x04, 0x10, 0x02, 0x18, 0x28,
+	0x52, 0x04, 0x6e, 0x61, 0x6d, 0x65, 0x12, 0x14, 0x0a, 0x05, 0x63, 0x6f, 0x75, 0x6e, 0x74, 0x18,
+	0x02, 0x20, 0x01, 0x28, 0x03, 0x52, 0x05, 0x63, 0x6f, 0x75, 0x6e, 0x74, 0x32, 0xb7, 0x01, 0x0a,
+	0x07, 0x47, 0x72, 0x65, 0x65, 0x74, 0x65, 0x72, 0x12, 0x5e, 0x0a, 0x08, 0x53, 0x61, 0x79, 0x48,
+	0x65, 0x6c, 0x6c, 0x6f, 0x12, 0x18, 0x2e, 0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x77, 0x6f, 0x72, 0x6c,
+	0x64, 0x2e, 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x52, 0x65, 0x71, 0x75, 0x65, 0x73, 0x74, 0x1a, 0x16,
+	0x2e, 0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x77, 0x6f, 0x72, 0x6c, 0x64, 0x2e, 0x48, 0x65, 0x6c, 0x6c,
+	0x6f, 0x52, 0x65, 0x70, 0x6c, 0x79, 0x22, 0x20, 0x82, 0xd3, 0xe4, 0x93, 0x02, 0x1a, 0x22, 0x15,
+	0x2f, 0x61, 0x70, 0x69, 0x2f, 0x76, 0x31, 0x2f, 0x67, 0x72, 0x65, 0x65, 0x74, 0x65, 0x72, 0x2f,
+	0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x3a, 0x01, 0x2a, 0x12, 0x4c, 0x0a, 0x0e, 0x53, 0x61, 0x79, 0x48,
+	0x65, 0x6c, 0x6c, 0x6f, 0x53, 0x74, 0x72, 0x65, 0x61, 0x6d, 0x12, 0x1e, 0x2e, 0x68, 0x65, 0x6c,
+	0x6c, 0x6f, 0x77, 0x6f, 0x72, 0x6c, 0x64, 0x2e, 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x53, 0x74, 0x72,
+	0x65, 0x61, 0x6d, 0x52, 0x65, 0x71, 0x75, 0x65, 0x73, 0x74, 0x1a, 0x16, 0x2e, 0x68, 0x65, 0x6c,
+	0x6c, 0x6f, 0x77, 0x6f, 0x72, 0x6c, 0x64, 0x2e, 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x52, 0x65, 0x70,
+	0x6c, 0x79, 0x22, 0x00, 0x30, 0x01, 0x42, 0x22, 0x5a, 0x20, 0x67, 0x6f, 0x2e, 0x6c, 0x69, 0x6e,
+	0x6b, 0x61, 0x2e, 0x63, 0x6c, 0x6f, 0x75, 0x64, 0x2f, 0x67, 0x72, 0x70, 0x63, 0x2f, 0x65, 0x78,
+	0x61, 0x6d, 0x70, 0x6c, 0x65, 0x3b, 0x6d, 0x61, 0x69, 0x6e, 0x62, 0x06, 0x70, 0x72, 0x6f, 0x74,
+	0x6f, 0x33,
 }
 
 var (
diff --git a/example/example.pb.validate.go b/example/example.pb.validate.go
index bc3cad3..980331c 100644
--- a/example/example.pb.validate.go
+++ b/example/example.pb.validate.go
@@ -46,7 +46,16 @@ func (m *HelloRequest) Validate(all bool) error {
 
 	var errors []error
 
-	// no validation rules for Name
+	if l := utf8.RuneCountInString(m.GetName()); l < 2 || l > 40 {
+		err := HelloRequestValidationError{
+			field:  "Name",
+			reason: "value length must be between 2 and 40 runes, inclusive",
+		}
+		if !all {
+			return err
+		}
+		errors = append(errors, err)
+	}
 
 	if len(errors) > 0 {
 		return HelloRequestMultiError(errors)
@@ -229,7 +238,16 @@ func (m *HelloStreamRequest) Validate(all bool) error {
 
 	var errors []error
 
-	// no validation rules for Name
+	if l := utf8.RuneCountInString(m.GetName()); l < 2 || l > 40 {
+		err := HelloStreamRequestValidationError{
+			field:  "Name",
+			reason: "value length must be between 2 and 40 runes, inclusive",
+		}
+		if !all {
+			return err
+		}
+		errors = append(errors, err)
+	}
 
 	// no validation rules for Count
 
diff --git a/example/example.proto b/example/example.proto
index 11399a8..9f860d6 100644
--- a/example/example.proto
+++ b/example/example.proto
@@ -5,6 +5,7 @@ package helloworld;
 option go_package = "go.linka.cloud/grpc/example;main";
 
 import "google/api/annotations.proto";
+import "validate/validate.proto";
 
 service Greeter {
     rpc SayHello (HelloRequest) returns (HelloReply) {
@@ -17,7 +18,7 @@ service Greeter {
 }
 
 message HelloRequest {
-    string name = 1;
+    string name = 1 [(validate.rules).string = {min_len: 2, max_len: 40}];
 }
 
 message HelloReply {
@@ -25,6 +26,6 @@ message HelloReply {
 }
 
 message HelloStreamRequest {
-    string name = 1;
+    string name = 1 [(validate.rules).string = {min_len: 2, max_len: 40}];
     int64 count = 2;
 }
diff --git a/go.mod b/go.mod
index 2bb1fa7..af5fcbc 100644
--- a/go.mod
+++ b/go.mod
@@ -10,7 +10,9 @@ require (
 	github.com/golang/protobuf v1.5.2
 	github.com/google/uuid v1.1.2
 	github.com/grpc-ecosystem/go-grpc-middleware v1.3.0
+	github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.5.0
+	github.com/grpc-ecosystem/grpc-opentracing v0.0.0-20180507213350-8e809c8a8645
 	github.com/iancoleman/strcase v0.2.0 // indirect
 	github.com/improbable-eng/grpc-web v0.14.1
 	github.com/jinzhu/gorm v1.9.12
@@ -19,6 +21,7 @@ require (
 	github.com/lyft/protoc-gen-star v0.6.0 // indirect
 	github.com/miekg/dns v1.1.35
 	github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e // indirect
+	github.com/opentracing/opentracing-go v1.1.0
 	github.com/planetscale/vtprotobuf v0.2.0
 	github.com/rs/cors v1.7.0
 	github.com/sirupsen/logrus v1.8.1
diff --git a/go.sum b/go.sum
index b7974ee..d247823 100644
--- a/go.sum
+++ b/go.sum
@@ -91,6 +91,7 @@ github.com/aws/aws-sdk-go-v2 v0.18.0/go.mod h1:JWVYvqSMppoMJC0x5wdwiImzgXTI9FuZw
 github.com/aybabtme/rgbterm v0.0.0-20170906152045-cc83f3b3ce59/go.mod h1:q/89r3U2H7sSsE2t6Kca0lfwTK8JdoNGS/yzM/4iH5I=
 github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
 github.com/beorn7/perks v1.0.0/go.mod h1:KWe93zE9D1o94FZ5RNwFwVgaQK1VOXiVxmqh+CedLV8=
+github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
 github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
 github.com/bgentry/speakeasy v0.1.0/go.mod h1:+zsyZBPWlz7T6j88CTgSN5bM796AkVf0kBD4zp0CCIs=
 github.com/bketelsen/crypt v0.0.3-0.20200106085610-5cbc8cc4026c/go.mod h1:MKsuJmJgSg28kpZDP6UIiPt0e0Oz0kqKNGyRaWEPv84=
@@ -102,7 +103,9 @@ github.com/cavaliercoder/go-cpio v0.0.0-20180626203310-925f9528c45e/go.mod h1:oD
 github.com/cenkalti/backoff v2.2.1+incompatible/go.mod h1:90ReRw6GdpyfrHakVjL/QHaoyV4aDUVVkXQJJJ3NXXM=
 github.com/census-instrumentation/opencensus-proto v0.2.0/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
 github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
+github.com/cespare/xxhash v1.1.0 h1:a6HrQnmkObjyL+Gs60czilIUGqrzKutQD6XZog3p+ko=
 github.com/cespare/xxhash v1.1.0/go.mod h1:XrSqR1VqqWfGrhpAt58auRo0WTKS1nRRg3ghfAqPWnc=
+github.com/cespare/xxhash/v2 v2.1.1 h1:6MnRN8NT7+YBpUIWxHtefFZOKTAPgGjpQSxqLNn0+qY=
 github.com/cespare/xxhash/v2 v2.1.1/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/chzyer/logex v1.1.10/go.mod h1:+Ywpsq7O8HXn0nuIou7OrIPyXbp3wmkHB+jjWRnGsAI=
 github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e/go.mod h1:nSuG5e5PlCu98SY8svDHJxuZscDgtXS6KTTbou5AhLI=
@@ -299,6 +302,7 @@ github.com/grpc-ecosystem/go-grpc-middleware v1.0.1-0.20190118093823-f849b5445de
 github.com/grpc-ecosystem/go-grpc-middleware v1.2.2/go.mod h1:EaizFBKfUKtMIF5iaDEhniwNedqGo9FuLFzppDr3uwI=
 github.com/grpc-ecosystem/go-grpc-middleware v1.3.0 h1:+9834+KizmvFV7pXQGSXQTsaWhq2GjuNUt0aUU0YBYw=
 github.com/grpc-ecosystem/go-grpc-middleware v1.3.0/go.mod h1:z0ButlSOZa5vEBq9m2m2hlwIgKw+rp3sdCBRoJY+30Y=
+github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0 h1:Ovs26xHkKqVztRpIrF/92BcuyuQ/YW4NSIpoGtfXNho=
 github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0/go.mod h1:8NvIoxWQoOIhqOTXgfV/d3M/q6VIi02HzZEHgUlZvzk=
 github.com/grpc-ecosystem/grpc-gateway v1.8.5/go.mod h1:vNeuVxBJEsws4ogUvrchl83t/GYV9WGTSLVdBhOQFDY=
 github.com/grpc-ecosystem/grpc-gateway v1.9.0/go.mod h1:vNeuVxBJEsws4ogUvrchl83t/GYV9WGTSLVdBhOQFDY=
@@ -306,6 +310,8 @@ github.com/grpc-ecosystem/grpc-gateway v1.9.2/go.mod h1:vNeuVxBJEsws4ogUvrchl83t
 github.com/grpc-ecosystem/grpc-gateway v1.9.5/go.mod h1:vNeuVxBJEsws4ogUvrchl83t/GYV9WGTSLVdBhOQFDY=
 github.com/grpc-ecosystem/grpc-gateway v1.16.0 h1:gmcG1KaJ57LophUzW0Hy8NmPhnMZb4M0+kPpLofRdBo=
 github.com/grpc-ecosystem/grpc-gateway v1.16.0/go.mod h1:BDjrQk3hbvj6Nolgz8mAMFbcEtjT1g+wF4CSlocrBnw=
+github.com/grpc-ecosystem/grpc-opentracing v0.0.0-20180507213350-8e809c8a8645 h1:MJG/KsmcqMwFAkh8mTnAwhyKoB+sTAnY4CACC110tbU=
+github.com/grpc-ecosystem/grpc-opentracing v0.0.0-20180507213350-8e809c8a8645/go.mod h1:6iZfnjpejD4L/4DwD7NryNaJyCQdzwWwH2MWhCA90Kw=
 github.com/hashicorp/consul/api v1.1.0/go.mod h1:VmuI/Lkw1nC05EYQWNKwWGbkg+FbDBtguAZLlVdkD9Q=
 github.com/hashicorp/consul/api v1.3.0/go.mod h1:MmDNSzIMUjNpY/mQ398R4bk2FnqQLoPndWW5VkKPlCE=
 github.com/hashicorp/consul/sdk v0.1.1/go.mod h1:VKf9jXwCTEY1QZP2MOLRhb5i/I/ssyNV1vwHyQBF0x8=
@@ -429,6 +435,7 @@ github.com/mattn/go-shellwords v1.0.10/go.mod h1:EZzvwXDESEeg03EKmM+RmDnNOPKG4lL
 github.com/mattn/go-sqlite3 v2.0.1+incompatible h1:xQ15muvnzGBHpIpdrNi1DA5x0+TcBZzsIDwmw9uTHzw=
 github.com/mattn/go-sqlite3 v2.0.1+incompatible/go.mod h1:FPy6KqzDD04eiIsT53CuJW3U88zkxoIYsOqkbpncsNc=
 github.com/mattn/go-zglob v0.0.1/go.mod h1:9fxibJccNxU2cnpIKLRRFA7zX7qhkJIQWBb449FYHOo=
+github.com/matttproud/golang_protobuf_extensions v1.0.1 h1:4hp9jkHxhMHkqkrB3Ix0jegS5sx/RkqARlsWZ6pIwiU=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
 github.com/mgutz/ansi v0.0.0-20170206155736-9520e82c474b/go.mod h1:01TrycV0kFyexm33Z7vhZRXopbI8J3TDReVlkTgMUxE=
 github.com/miekg/dns v1.0.14/go.mod h1:W1PPwlIAgtquWBMBEV9nkV9Cazfe8ScdGz/Lj7v3Nrg=
@@ -475,6 +482,7 @@ github.com/op/go-logging v0.0.0-20160315200505-970db520ece7/go.mod h1:HzydrMdWEr
 github.com/opentracing-contrib/go-observer v0.0.0-20170622124052-a52f23424492/go.mod h1:Ngi6UdF0k5OKD5t5wlmGhe/EDKPoUM3BXZSSfIuJbis=
 github.com/opentracing/basictracer-go v1.0.0/go.mod h1:QfBfYuafItcjQuMwinw9GhYKwFXS9KnPs5lxoYwgW74=
 github.com/opentracing/opentracing-go v1.0.2/go.mod h1:UkNAQd3GIcIGf0SeVgPpRdFStlNbqXla1AfSYxPUl2o=
+github.com/opentracing/opentracing-go v1.1.0 h1:pWlfV3Bxv7k65HYwkikxat0+s3pV4bsqf19k25Ur8rU=
 github.com/opentracing/opentracing-go v1.1.0/go.mod h1:UkNAQd3GIcIGf0SeVgPpRdFStlNbqXla1AfSYxPUl2o=
 github.com/openzipkin-contrib/zipkin-go-opentracing v0.4.5/go.mod h1:/wsWhb9smxSfWAKL3wpBW7V8scJMt8N8gnaMCS9E/cA=
 github.com/openzipkin/zipkin-go v0.1.6/go.mod h1:QgAqvLzwWbR/WpD4A3cGpPtJrZXNIiJc5AZX7/PBEpw=
@@ -504,12 +512,14 @@ github.com/prometheus/client_golang v0.9.3/go.mod h1:/TN21ttK/J9q6uSwhBd54HahCDf
 github.com/prometheus/client_golang v1.0.0/go.mod h1:db9x61etRT2tGnBNRi70OPL5FsnadC4Ky3P0J6CfImo=
 github.com/prometheus/client_golang v1.3.0/go.mod h1:hJaj2vgQTGQmVCsAACORcieXFeDPbaTKGT+JTgUa3og=
 github.com/prometheus/client_golang v1.7.1/go.mod h1:PY5Wy2awLA44sXw4AOSfFBetzPP4j5+D6mVACh+pe2M=
+github.com/prometheus/client_golang v1.11.0 h1:HNkLOAEQMIDv/K+04rukrLx6ch7msSRwf3/SASFAGtQ=
 github.com/prometheus/client_golang v1.11.0/go.mod h1:Z6t4BnS23TR94PD6BsDNk8yVqroYurpAkEiz0P2BEV0=
 github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910/go.mod h1:MbSGuTsp3dbXC40dX6PRTWyKYBIrTGTE9sqQNg2J8bo=
 github.com/prometheus/client_model v0.0.0-20190115171406-56726106282f/go.mod h1:MbSGuTsp3dbXC40dX6PRTWyKYBIrTGTE9sqQNg2J8bo=
 github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
 github.com/prometheus/client_model v0.1.0/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
+github.com/prometheus/client_model v0.2.0 h1:uq5h0d+GuxiXLJLNABMgp2qUWDPiLvgCzz2dUR+/W/M=
 github.com/prometheus/client_model v0.2.0/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
 github.com/prometheus/common v0.0.0-20181113130724-41aa239b4cce/go.mod h1:daVV7qP5qjZbuso7PdcryaAu0sAZbrN9i7WWcTMWvro=
 github.com/prometheus/common v0.2.0/go.mod h1:TNfzLD0ON7rHzMJeJkieUDPYmFC7Snx/y86RQel1bk4=
@@ -528,6 +538,7 @@ github.com/prometheus/procfs v0.0.2/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsT
 github.com/prometheus/procfs v0.0.8/go.mod h1:7Qr8sr6344vo1JqZ6HhLceV9o3AJ1Ff+GxbHq6oeK9A=
 github.com/prometheus/procfs v0.1.3/go.mod h1:lV6e/gmhEcM9IjHGsFOCxxuZ+z1YqCvr4OA4YeYWdaU=
 github.com/prometheus/procfs v0.3.0/go.mod h1:lV6e/gmhEcM9IjHGsFOCxxuZ+z1YqCvr4OA4YeYWdaU=
+github.com/prometheus/procfs v0.6.0 h1:mxy4L2jP6qMonqmq+aTtOx1ifVWUgG/TAmntgbh3xv4=
 github.com/prometheus/procfs v0.6.0/go.mod h1:cz+aTbrPOrUb4q7XlbU9ygM+/jj0fzG6c1xBZuNvfVA=
 github.com/prometheus/tsdb v0.7.1/go.mod h1:qhTCs0VvXwvX/y3TZrWD7rabWM+ijKTux40TwIPHuXU=
 github.com/rcrowley/go-metrics v0.0.0-20181016184325-3113b8401b8a/go.mod h1:bCqnVzQkZxMG4s8nGwiZ5l3QUCyqpo9Y+/ZMZ9VjZe4=
diff --git a/interceptors/interceptors.go b/interceptors/interceptors.go
new file mode 100644
index 0000000..72ae9cb
--- /dev/null
+++ b/interceptors/interceptors.go
@@ -0,0 +1,20 @@
+package interceptors
+
+import (
+	"google.golang.org/grpc"
+)
+
+type ServerInterceptors interface {
+	UnaryServerInterceptor() grpc.UnaryServerInterceptor
+	StreamServerInterceptor() grpc.StreamServerInterceptor
+}
+
+type ClientInterceptors interface {
+	UnaryClientInterceptor() grpc.UnaryClientInterceptor
+	StreamClientInterceptor() grpc.StreamClientInterceptor
+}
+
+type Interceptors interface {
+	ServerInterceptors
+	ClientInterceptors
+}
diff --git a/interceptors/metrics/interceptors.go b/interceptors/metrics/interceptors.go
new file mode 100644
index 0000000..da98cc9
--- /dev/null
+++ b/interceptors/metrics/interceptors.go
@@ -0,0 +1,57 @@
+package metrics
+
+import (
+	grpc_prometheus "github.com/grpc-ecosystem/go-grpc-prometheus"
+	"google.golang.org/grpc"
+
+	"go.linka.cloud/grpc/interceptors"
+)
+
+type metrics struct {
+	s *grpc_prometheus.ServerMetrics
+	c *grpc_prometheus.ClientMetrics
+}
+
+func NewInterceptors(opts ...grpc_prometheus.CounterOption) interceptors.Interceptors {
+	s := grpc_prometheus.NewServerMetrics(opts...)
+	c := grpc_prometheus.NewClientMetrics(opts...)
+	return &metrics{s: s, c: c}
+}
+
+func NewServerInterceptors(opts ...grpc_prometheus.CounterOption) interceptors.ServerInterceptors {
+	s := grpc_prometheus.NewServerMetrics(opts...)
+	return &metrics{s: s}
+}
+
+func NewClientInterceptors(opts ...grpc_prometheus.CounterOption) interceptors.ClientInterceptors {
+	c := grpc_prometheus.NewClientMetrics(opts...)
+	return &metrics{c: c}
+}
+
+func DefaultInterceptors() interceptors.Interceptors {
+	return &metrics{s: grpc_prometheus.DefaultServerMetrics, c: grpc_prometheus.DefaultClientMetrics}
+}
+
+func DefaultServerInterceptors() interceptors.ServerInterceptors {
+	return &metrics{s: grpc_prometheus.DefaultServerMetrics}
+}
+
+func DefaultClientInterceptors() interceptors.ClientInterceptors {
+	return &metrics{c: grpc_prometheus.DefaultClientMetrics}
+}
+
+func (m *metrics) UnaryServerInterceptor() grpc.UnaryServerInterceptor {
+	return m.s.UnaryServerInterceptor()
+}
+
+func (m *metrics) StreamServerInterceptor() grpc.StreamServerInterceptor {
+	return m.s.StreamServerInterceptor()
+}
+
+func (m *metrics) UnaryClientInterceptor() grpc.UnaryClientInterceptor {
+	return m.c.UnaryClientInterceptor()
+}
+
+func (m *metrics) StreamClientInterceptor() grpc.StreamClientInterceptor {
+	return m.c.StreamClientInterceptor()
+}
diff --git a/interceptors/tracing/interceptors.go b/interceptors/tracing/interceptors.go
new file mode 100644
index 0000000..5c44c4c
--- /dev/null
+++ b/interceptors/tracing/interceptors.go
@@ -0,0 +1,41 @@
+package tracing
+
+import (
+	"github.com/grpc-ecosystem/grpc-opentracing/go/otgrpc"
+	"github.com/opentracing/opentracing-go"
+	"google.golang.org/grpc"
+
+	"go.linka.cloud/grpc/interceptors"
+)
+
+type tracing struct {
+	opts []otgrpc.Option
+}
+
+func NewInterceptors(opts ...otgrpc.Option) interceptors.Interceptors {
+	return tracing{opts: opts}
+}
+
+func NewClientInterceptors(opts ...otgrpc.Option) interceptors.ClientInterceptors {
+	return tracing{opts: opts}
+}
+
+func (t tracing) UnaryClientInterceptor() grpc.UnaryClientInterceptor {
+	return otgrpc.OpenTracingClientInterceptor(opentracing.GlobalTracer(), t.opts...)
+}
+
+func (t tracing) StreamClientInterceptor() grpc.StreamClientInterceptor {
+	return otgrpc.OpenTracingStreamClientInterceptor(opentracing.GlobalTracer(), t.opts...)
+}
+
+func NewServerInterceptors(opts ...otgrpc.Option) interceptors.ServerInterceptors {
+	return tracing{opts: opts}
+}
+
+func (t tracing) UnaryServerInterceptor() grpc.UnaryServerInterceptor {
+	return otgrpc.OpenTracingServerInterceptor(opentracing.GlobalTracer(), t.opts...)
+}
+
+func (t tracing) StreamServerInterceptor() grpc.StreamServerInterceptor {
+	return otgrpc.OpenTracingStreamServerInterceptor(opentracing.GlobalTracer(), t.opts...)
+}
diff --git a/interceptors/validation/interceptors.go b/interceptors/validation/interceptors.go
new file mode 100644
index 0000000..958ae1a
--- /dev/null
+++ b/interceptors/validation/interceptors.go
@@ -0,0 +1 @@
+package validation
diff --git a/interceptors/validation/validation.go b/interceptors/validation/validation.go
new file mode 100644
index 0000000..24196da
--- /dev/null
+++ b/interceptors/validation/validation.go
@@ -0,0 +1,161 @@
+package validation
+
+import (
+	"context"
+
+	"google.golang.org/genproto/googleapis/rpc/errdetails"
+	"google.golang.org/grpc"
+	"google.golang.org/protobuf/proto"
+
+	"go.linka.cloud/grpc/errors"
+	"go.linka.cloud/grpc/interceptors"
+)
+
+// The validate interface starting with protoc-gen-validate v0.6.0.
+// See https://github.com/envoyproxy/protoc-gen-validate/pull/455.
+type validator interface {
+	Validate(all bool) error
+}
+
+// The validate interface prior to protoc-gen-validate v0.6.0.
+type validatorLegacy interface {
+	Validate() error
+}
+
+type validatorMultiError interface {
+	AllErrors() []error
+}
+
+type validatorError interface {
+	Field() string
+	Reason() string
+	Key() bool
+	Cause() error
+	ErrorName() string
+}
+
+func validatorErrorToGrpc(e validatorError) *errdetails.BadRequest_FieldViolation {
+	return &errdetails.BadRequest_FieldViolation{
+		Field:       e.Field(),
+		Description: e.Reason(),
+	}
+}
+
+func errToStatus(err error) error {
+	switch v := err.(type) {
+	case validatorError:
+		return errors.InvalidArgumentD(err, validatorErrorToGrpc(v))
+	case validatorMultiError:
+		var details []proto.Message
+		for _, v := range v.AllErrors() {
+			if d, ok := v.(validatorError); ok {
+				details = append(details, validatorErrorToGrpc(d))
+			}
+		}
+		return errors.InvalidArgumentd(err, details...)
+	default:
+		return errors.InvalidArgument(err)
+	}
+}
+
+func (i interceptor) validate(req interface{}) error {
+	switch v := req.(type) {
+	case validatorLegacy:
+		if err := v.Validate(); err != nil {
+			return errToStatus(err)
+		}
+	case validator:
+		if err := v.Validate(i.all); err != nil {
+			return errToStatus(err)
+		}
+	}
+	return nil
+}
+
+type interceptor struct {
+	all bool
+}
+
+func NewInterceptors(validateAll bool) interceptors.Interceptors {
+	return &interceptor{all: validateAll}
+}
+
+// UnaryServerInterceptor returns a new unary server interceptor that validates incoming messages.
+//
+// Invalid messages will be rejected with `InvalidArgument` before reaching any userspace handlers.
+func (i interceptor) UnaryServerInterceptor() grpc.UnaryServerInterceptor {
+	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
+		if err := i.validate(req); err != nil {
+			return nil, err
+		}
+		return handler(ctx, req)
+	}
+}
+
+// UnaryClientInterceptor returns a new unary client interceptor that validates outgoing messages.
+//
+// Invalid messages will be rejected with `InvalidArgument` before sending the request to server.
+func (i interceptor) UnaryClientInterceptor() grpc.UnaryClientInterceptor {
+	return func(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
+		if err := i.validate(req); err != nil {
+			return err
+		}
+		return invoker(ctx, method, req, reply, cc, opts...)
+	}
+}
+
+// StreamServerInterceptor returns a new streaming server interceptor that validates incoming messages.
+//
+// The stage at which invalid messages will be rejected with `InvalidArgument` varies based on the
+// type of the RPC. For `ServerStream` (1:m) requests, it will happen before reaching any userspace
+// handlers. For `ClientStream` (n:1) or `BidiStream` (n:m) RPCs, the messages will be rejected on
+// calls to `stream.Recv()`.
+func (i interceptor) StreamServerInterceptor() grpc.StreamServerInterceptor {
+	return func(srv interface{}, stream grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+		wrapper := &recvWrapper{ServerStream: stream, i: i}
+		return handler(srv, wrapper)
+	}
+}
+
+func (i interceptor) StreamClientInterceptor() grpc.StreamClientInterceptor {
+	return func(ctx context.Context, desc *grpc.StreamDesc, cc *grpc.ClientConn, method string, streamer grpc.Streamer, opts ...grpc.CallOption) (grpc.ClientStream, error) {
+		desc.Handler = (&sendWrapper{handler: desc.Handler, i: i}).Handler()
+		return streamer(ctx, desc, cc, method)
+	}
+}
+
+type recvWrapper struct {
+	i interceptor
+	grpc.ServerStream
+}
+
+func (s *recvWrapper) RecvMsg(m interface{}) error {
+	if err := s.ServerStream.RecvMsg(m); err != nil {
+		return err
+	}
+
+	if err := s.i.validate(m); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+type sendWrapper struct {
+	i interceptor
+	grpc.ServerStream
+	handler grpc.StreamHandler
+}
+
+func (s *sendWrapper) Handler() grpc.StreamHandler {
+	return func(srv interface{}, stream grpc.ServerStream) error {
+		return s.handler(srv, s)
+	}
+}
+
+func (s *sendWrapper) SendMsg(m interface{}) error {
+	if err := s.i.validate(m); err != nil {
+		return err
+	}
+	return s.ServerStream.SendMsg(m)
+}
diff --git a/service/options.go b/service/options.go
index 193de65..43cb3ad 100644
--- a/service/options.go
+++ b/service/options.go
@@ -17,6 +17,7 @@ import (
 	"google.golang.org/grpc"
 
 	"go.linka.cloud/grpc/certs"
+	"go.linka.cloud/grpc/interceptors"
 	"go.linka.cloud/grpc/registry"
 	"go.linka.cloud/grpc/transport"
 	"go.linka.cloud/grpc/utils/addr"
@@ -228,16 +229,45 @@ func WithAfterStop(fn ...func() error) Option {
 	}
 }
 
+func WithInterceptors(i ...interceptors.Interceptors) Option {
+	return func(o *options) {
+		for _, v := range i {
+			o.unaryServerInterceptors = append(o.unaryServerInterceptors, v.UnaryServerInterceptor())
+			o.streamServerInterceptors = append(o.streamServerInterceptors, v.StreamServerInterceptor())
+			o.unaryClientInterceptors = append(o.unaryClientInterceptors, v.UnaryClientInterceptor())
+			o.streamClientInterceptors = append(o.streamClientInterceptors, v.StreamClientInterceptor())
+		}
+	}
+}
+
+func WithServerInterceptors(i ...interceptors.ServerInterceptors) Option {
+	return func(o *options) {
+		for _, v := range i {
+			o.unaryServerInterceptors = append(o.unaryServerInterceptors, v.UnaryServerInterceptor())
+			o.streamServerInterceptors = append(o.streamServerInterceptors, v.StreamServerInterceptor())
+		}
+	}
+}
+
+func WithClientInterceptors(i ...interceptors.ClientInterceptors) Option {
+	return func(o *options) {
+		for _, v := range i {
+			o.unaryClientInterceptors = append(o.unaryClientInterceptors, v.UnaryClientInterceptor())
+			o.streamClientInterceptors = append(o.streamClientInterceptors, v.StreamClientInterceptor())
+		}
+	}
+}
+
 func WithUnaryClientInterceptor(i ...grpc.UnaryClientInterceptor) Option {
 	return func(o *options) {
-		o.clientInterceptors = append(o.clientInterceptors, i...)
+		o.unaryClientInterceptors = append(o.unaryClientInterceptors, i...)
 	}
 }
 
 // WithUnaryServerInterceptor adds unary Wrapper interceptors to the options passed into the server
 func WithUnaryServerInterceptor(i ...grpc.UnaryServerInterceptor) Option {
 	return func(o *options) {
-		o.serverInterceptors = append(o.serverInterceptors, i...)
+		o.unaryServerInterceptors = append(o.unaryServerInterceptors, i...)
 	}
 }
 
@@ -340,10 +370,11 @@ type options struct {
 
 	serverOpts []grpc.ServerOption
 
-	serverInterceptors       []grpc.UnaryServerInterceptor
+
+	unaryServerInterceptors  []grpc.UnaryServerInterceptor
 	streamServerInterceptors []grpc.StreamServerInterceptor
 
-	clientInterceptors       []grpc.UnaryClientInterceptor
+	unaryClientInterceptors  []grpc.UnaryClientInterceptor
 	streamClientInterceptors []grpc.StreamClientInterceptor
 
 	mux           ServeMux
@@ -428,7 +459,7 @@ func (o *options) ServerOpts() []grpc.ServerOption {
 }
 
 func (o *options) ServerInterceptors() []grpc.UnaryServerInterceptor {
-	return o.serverInterceptors
+	return o.unaryServerInterceptors
 }
 
 func (o *options) StreamServerInterceptors() []grpc.StreamServerInterceptor {
@@ -436,7 +467,7 @@ func (o *options) StreamServerInterceptors() []grpc.StreamServerInterceptor {
 }
 
 func (o *options) ClientInterceptors() []grpc.UnaryClientInterceptor {
-	return o.clientInterceptors
+	return o.unaryClientInterceptors
 }
 
 func (o *options) StreamClientInterceptors() []grpc.StreamClientInterceptor {
diff --git a/service/service.go b/service/service.go
index 7445137..fe939bc 100644
--- a/service/service.go
+++ b/service/service.go
@@ -107,10 +107,10 @@ func newService(opts ...Option) (*service, error) {
 		}
 		return s.run()
 	}
-	ui := grpcmiddleware.ChainUnaryServer(s.opts.serverInterceptors...)
+	ui := grpcmiddleware.ChainUnaryServer(s.opts.unaryServerInterceptors...)
 	s.inproc = s.inproc.WithServerUnaryInterceptor(ui)
 
-	si := grpcmiddleware.ChainStreamServer(/*TODO(adphi): add to options*/)
+	si := grpcmiddleware.ChainStreamServer( /*TODO(adphi): add to options*/ )
 	s.inproc = s.inproc.WithServerStreamInterceptor(si)
 
 	gopts := []grpc.ServerOption{
@@ -181,8 +181,8 @@ func (s *service) run() error {
 
 	if reflect.DeepEqual(s.opts.cors, cors.Options{}) {
 		s.opts.cors = cors.Options{
-			AllowedHeaders:   []string{"*"},
-			AllowedMethods:   []string{
+			AllowedHeaders: []string{"*"},
+			AllowedMethods: []string{
 				http.MethodGet,
 				http.MethodPost,
 				http.MethodPut,
@@ -235,7 +235,7 @@ func (s *service) run() error {
 		logrus.Warnf("received %v", sig)
 		return s.Close()
 	case err := <-errs:
-		if err != nil && !ignoreMuxError(err){
+		if err != nil && !ignoreMuxError(err) {
 			logrus.Error(err)
 			return err
 		}
diff --git a/signals/signal_posix.go b/signals/signal_posix.go
index 9bdb4e7..a0f00a7 100644
--- a/signals/signal_posix.go
+++ b/signals/signal_posix.go
@@ -1,3 +1,4 @@
+//go:build !windows
 // +build !windows
 
 /*