diff --git a/build/test/server.go b/build/test/server.go
index 125f4532ae..ffb40349d5 100644
--- a/build/test/server.go
+++ b/build/test/server.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package test is for integration testing.
 package test
 
 import (
diff --git a/cmd/client/command/common.go b/cmd/client/command/common.go
index 65a5a0d8c0..49f6346c46 100644
--- a/cmd/client/command/common.go
+++ b/cmd/client/command/common.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package command implements commands of Easegress client.
 package command
 
 import (
diff --git a/cmd/client/main.go b/cmd/client/main.go
index 404ceeb312..cc7d512a55 100644
--- a/cmd/client/main.go
+++ b/cmd/client/main.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package main is the entry point of Easegress client.
 package main
 
 import (
diff --git a/cmd/server/main.go b/cmd/server/main.go
index 8d62b6ceee..c41ab5d6d5 100644
--- a/cmd/server/main.go
+++ b/cmd/server/main.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package main is the entry point of Easegress server.
 package main
 
 import (
diff --git a/example/backend-service/echo/echo.go b/example/backend-service/echo/echo.go
index e7ccaecd2a..12f837b5a8 100644
--- a/example/backend-service/echo/echo.go
+++ b/example/backend-service/echo/echo.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package main is the entry point of the simple echo server.
 package main
 
 import (
diff --git a/example/backend-service/mirror/mirror.go b/example/backend-service/mirror/mirror.go
index ed4263c4ea..366c5aadba 100644
--- a/example/backend-service/mirror/mirror.go
+++ b/example/backend-service/mirror/mirror.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package main is the entry point of the simple mirror server.
 package main
 
 import (
diff --git a/example/backend-service/remote/remote.go b/example/backend-service/remote/remote.go
index 987b2889c5..0fa89b71c6 100644
--- a/example/backend-service/remote/remote.go
+++ b/example/backend-service/remote/remote.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package main is the entry point of the simple Easegress remote server.
 package main
 
 import (
diff --git a/pkg/api/api.go b/pkg/api/api.go
index 479d75ea69..dfd0f22269 100644
--- a/pkg/api/api.go
+++ b/pkg/api/api.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package api implements the HTTP API of Easegress.
 package api
 
 import (
diff --git a/pkg/cluster/cluster.go b/pkg/cluster/cluster.go
index c70507744d..2321386445 100644
--- a/pkg/cluster/cluster.go
+++ b/pkg/cluster/cluster.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package cluster provides the cluster management.
 package cluster
 
 import (
diff --git a/pkg/cluster/clustertest/cluster.go b/pkg/cluster/clustertest/cluster.go
index 3707042b27..441906b9d3 100644
--- a/pkg/cluster/clustertest/cluster.go
+++ b/pkg/cluster/clustertest/cluster.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package clustertest provides a mocked cluster for testing.
 package clustertest
 
 import (
@@ -124,6 +125,7 @@ func (mc *MockedCluster) Put(key, value string) error {
 	return nil
 }
 
+// PutUnderTimeout implements interface function PutUnderTimeout
 func (mc *MockedCluster) PutUnderTimeout(key, value string, timeout time.Duration) error {
 	if mc.MockedPutUnderTimeout != nil {
 		return mc.MockedPutUnderTimeout(key, value, timeout)
diff --git a/pkg/cluster/customdata/customdata.go b/pkg/cluster/customdata/customdata.go
index c053988439..8217f6f2b4 100644
--- a/pkg/cluster/customdata/customdata.go
+++ b/pkg/cluster/customdata/customdata.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package customdata provides a way to store custom data in Easegress cluster.
 package customdata
 
 import (
diff --git a/pkg/common/utils.go b/pkg/common/utils.go
index a8d78b121a..5d0cb24edc 100644
--- a/pkg/common/utils.go
+++ b/pkg/common/utils.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package common provides several common utilities for other packages.
 package common
 
 import (
diff --git a/pkg/context/context.go b/pkg/context/context.go
index b689c84559..16c56fe16e 100644
--- a/pkg/context/context.go
+++ b/pkg/context/context.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package context provides the context for traffic handlers.
 package context
 
 import (
diff --git a/pkg/context/contexttest/contexttest.go b/pkg/context/contexttest/contexttest.go
index 6c00f6a1a5..81157e6122 100644
--- a/pkg/context/contexttest/contexttest.go
+++ b/pkg/context/contexttest/contexttest.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package contexttest provides utilities for testing context.
 package contexttest
 
 import "github.com/megaease/easegress/pkg/context"
diff --git a/pkg/env/env.go b/pkg/env/env.go
index 6209fcb24e..f19ef3590b 100644
--- a/pkg/env/env.go
+++ b/pkg/env/env.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package env provides functions for environment variables.
 package env
 
 import (
diff --git a/pkg/filters/builder/builder.go b/pkg/filters/builder/builder.go
index 393babccc2..f2b8a8191b 100644
--- a/pkg/filters/builder/builder.go
+++ b/pkg/filters/builder/builder.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package builder implements builder filters.
 package builder
 
 import (
diff --git a/pkg/filters/builder/requestadaptor.go b/pkg/filters/builder/requestadaptor.go
index 6cfc6af19b..f4c00d2999 100644
--- a/pkg/filters/builder/requestadaptor.go
+++ b/pkg/filters/builder/requestadaptor.go
@@ -150,6 +150,7 @@ type (
 		Sign                   *SignerSpec `json:"sign,omitempty" jsonschema:"omitempty"`
 	}
 
+	// RequestAdaptorTemplate is the template of the request adaptor.
 	RequestAdaptorTemplate struct {
 		Host   string                `json:"host" jsonschema:"omitempty"`
 		Method string                `json:"method" jsonschema:"omitempty,format=httpmethod"`
diff --git a/pkg/filters/builder/responseadaptor.go b/pkg/filters/builder/responseadaptor.go
index a1f6b9bd57..362e9ff0f4 100644
--- a/pkg/filters/builder/responseadaptor.go
+++ b/pkg/filters/builder/responseadaptor.go
@@ -74,6 +74,7 @@ type (
 		Decompress              string `json:"decompress" jsonschema:"omitempty"`
 	}
 
+	// ResponseAdaptorTemplate is the template of ResponseAdaptor.
 	ResponseAdaptorTemplate struct {
 		Header *httpheader.AdaptSpec `json:"header" jsonschema:"omitempty"`
 		Body   string                `json:"body" jsonschema:"omitempty"`
diff --git a/pkg/filters/certextractor/certextractor.go b/pkg/filters/certextractor/certextractor.go
index aca1f19677..914b7eecaf 100644
--- a/pkg/filters/certextractor/certextractor.go
+++ b/pkg/filters/certextractor/certextractor.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package certextractor implements a filter to extract given field from TLS.
 package certextractor
 
 import (
diff --git a/pkg/filters/connectcontrol/connectcontrol.go b/pkg/filters/connectcontrol/connectcontrol.go
index b36f7e2cd7..5619c87916 100644
--- a/pkg/filters/connectcontrol/connectcontrol.go
+++ b/pkg/filters/connectcontrol/connectcontrol.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package connectcontrol implements filter for controlling connections of MQTT clients
 package connectcontrol
 
 import (
diff --git a/pkg/filters/corsadaptor/corsadaptor.go b/pkg/filters/corsadaptor/corsadaptor.go
index 1c0e40f661..9ee3300bbb 100644
--- a/pkg/filters/corsadaptor/corsadaptor.go
+++ b/pkg/filters/corsadaptor/corsadaptor.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package corsadaptor implements a filter that adapts CORS stuff.
 package corsadaptor
 
 import (
diff --git a/pkg/filters/fallback/fallback.go b/pkg/filters/fallback/fallback.go
index 19801b2e66..d455ea2341 100644
--- a/pkg/filters/fallback/fallback.go
+++ b/pkg/filters/fallback/fallback.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package fallback implements the fallback filter.
 package fallback
 
 import (
diff --git a/pkg/filters/filters.go b/pkg/filters/filters.go
index cb7f7281e6..ed8bb42261 100644
--- a/pkg/filters/filters.go
+++ b/pkg/filters/filters.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package filters implements common functionality of filters.
 package filters
 
 import (
diff --git a/pkg/filters/headerlookup/headerlookup.go b/pkg/filters/headerlookup/headerlookup.go
index 45ef853c20..0cf78d1108 100644
--- a/pkg/filters/headerlookup/headerlookup.go
+++ b/pkg/filters/headerlookup/headerlookup.go
@@ -15,6 +15,8 @@
 * limitations under the License.
  */
 
+// Package headerlookup implements a filter that enriches request headers
+// per request, looking up values from etcd.
 package headerlookup
 
 import (
diff --git a/pkg/filters/headertojson/headertojson.go b/pkg/filters/headertojson/headertojson.go
index 03362bdf9b..d1fc76e497 100644
--- a/pkg/filters/headertojson/headertojson.go
+++ b/pkg/filters/headertojson/headertojson.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package headertojson implements a filter to convert HTTP request header to json.
 package headertojson
 
 import (
diff --git a/pkg/filters/kafka/kafka.go b/pkg/filters/kafka/kafka.go
index 1d0665d174..7ad23f1b18 100644
--- a/pkg/filters/kafka/kafka.go
+++ b/pkg/filters/kafka/kafka.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package kafka implements a kafka proxy for MQTT requests.
 package kafka
 
 import (
@@ -36,7 +37,7 @@ const (
 
 var kind = &filters.Kind{
 	Name:        Kind,
-	Description: "Kafka is a backend of MQTTProxy",
+	Description: "Kafka is a kafka proxy for MQTT requests",
 	Results:     []string{resultGetDataFailed},
 	DefaultSpec: func() filters.Spec {
 		return &Spec{}
@@ -51,7 +52,7 @@ func init() {
 }
 
 type (
-	// Kafka is kafka backend for MQTT proxy
+	// Kafka is a kafka proxy for MQTT requests.
 	Kafka struct {
 		spec     *Spec
 		producer sarama.AsyncProducer
diff --git a/pkg/filters/kafka/kafka_test.go b/pkg/filters/kafka/kafka_test.go
index 9fbfa32407..4dd2fbf821 100644
--- a/pkg/filters/kafka/kafka_test.go
+++ b/pkg/filters/kafka/kafka_test.go
@@ -63,11 +63,11 @@ func (m *mockAsyncProducer) AbortTxn() error {
 	return nil
 }
 
-func (m *mockAsyncProducer) AddOffsetsToTxn(offsets map[string][]*sarama.PartitionOffsetMetadata, groupId string) error {
+func (m *mockAsyncProducer) AddOffsetsToTxn(offsets map[string][]*sarama.PartitionOffsetMetadata, groupID string) error {
 	return nil
 }
 
-func (m *mockAsyncProducer) AddMessageToTxn(msg *sarama.ConsumerMessage, groupId string, metadata *string) error {
+func (m *mockAsyncProducer) AddMessageToTxn(msg *sarama.ConsumerMessage, groupID string, metadata *string) error {
 	return nil
 }
 
diff --git a/pkg/filters/kafkabackend/kafka.go b/pkg/filters/kafkabackend/kafka.go
index 1de1c4bcb0..ec0080df84 100644
--- a/pkg/filters/kafkabackend/kafka.go
+++ b/pkg/filters/kafkabackend/kafka.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package kafka implements a kafka proxy for HTTP requests.
 package kafka
 
 import (
@@ -38,7 +39,7 @@ const (
 
 var kind = &filters.Kind{
 	Name:        Kind,
-	Description: "Kafka is a backend of MQTTProxy",
+	Description: "Kafka is a kafka proxy for HTTP requests",
 	Results:     []string{resultParseErr},
 	DefaultSpec: func() filters.Spec {
 		return &Spec{}
@@ -53,7 +54,7 @@ func init() {
 }
 
 type (
-	// Kafka is kafka backend for MQTT proxy
+	// Kafka is a kafka proxy for HTTP requests.
 	Kafka struct {
 		spec     *Spec
 		producer sarama.AsyncProducer
diff --git a/pkg/filters/kafkabackend/kafka_test.go b/pkg/filters/kafkabackend/kafka_test.go
index d793b66096..9faa5a6779 100644
--- a/pkg/filters/kafkabackend/kafka_test.go
+++ b/pkg/filters/kafkabackend/kafka_test.go
@@ -59,11 +59,11 @@ func (m *mockAsyncProducer) AbortTxn() error {
 	return nil
 }
 
-func (m *mockAsyncProducer) AddOffsetsToTxn(offsets map[string][]*sarama.PartitionOffsetMetadata, groupId string) error {
+func (m *mockAsyncProducer) AddOffsetsToTxn(offsets map[string][]*sarama.PartitionOffsetMetadata, groupID string) error {
 	return nil
 }
 
-func (m *mockAsyncProducer) AddMessageToTxn(msg *sarama.ConsumerMessage, groupId string, metadata *string) error {
+func (m *mockAsyncProducer) AddMessageToTxn(msg *sarama.ConsumerMessage, groupID string, metadata *string) error {
 	return nil
 }
 
diff --git a/pkg/filters/meshadaptor/meshadaptor.go b/pkg/filters/meshadaptor/meshadaptor.go
index 528f278ca8..28509b4517 100644
--- a/pkg/filters/meshadaptor/meshadaptor.go
+++ b/pkg/filters/meshadaptor/meshadaptor.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package meshadaptor provides MeshAdaptor filter.
 package meshadaptor
 
 import (
diff --git a/pkg/filters/mock/mock.go b/pkg/filters/mock/mock.go
index cda7177a73..76c4b328c4 100644
--- a/pkg/filters/mock/mock.go
+++ b/pkg/filters/mock/mock.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package mock provides Mock filter.
 package mock
 
 import (
diff --git a/pkg/filters/mqttclientauth/mqttauth.go b/pkg/filters/mqttclientauth/mqttauth.go
index da1d4b56ca..2a0515f5b9 100644
--- a/pkg/filters/mqttclientauth/mqttauth.go
+++ b/pkg/filters/mqttclientauth/mqttauth.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package mqttclientauth implements authentication for MQTT clients.
 package mqttclientauth
 
 import (
diff --git a/pkg/filters/oidcadaptor/oidcadaptor.go b/pkg/filters/oidcadaptor/oidcadaptor.go
index 3025631479..40d5c48e77 100644
--- a/pkg/filters/oidcadaptor/oidcadaptor.go
+++ b/pkg/filters/oidcadaptor/oidcadaptor.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package oidcadaptor implements OpenID Connect authorization.
 package oidcadaptor
 
 import (
@@ -67,6 +68,7 @@ type store interface {
 	get(key string) string
 }
 
+// OIDCAdaptor is the filter for OpenID Connect authorization.
 type OIDCAdaptor struct {
 	spec *Spec
 	store
@@ -82,12 +84,13 @@ type OIDCAdaptor struct {
 	jwks         *keyfunc.JWKS
 }
 
+// Spec defines the spec of OIDCAdaptor.
 type Spec struct {
 	filters.BaseSpec `yaml:",inline"`
 
 	CookieName string `json:"cookieName"`
 
-	ClientId     string `json:"clientId" jsonschema:"required"`
+	ClientID     string `json:"clientId" jsonschema:"required"`
 	ClientSecret string `json:"clientSecret" jsonschema:"required"`
 
 	Discovery string `json:"discovery"`
@@ -107,10 +110,10 @@ type oidcConfig struct {
 	TokenEndpoint                     string   `json:"token_endpoint"`
 	UserInfoEndpoint                  string   `json:"userinfo_endpoint"`
 	RevocationEndpoint                string   `json:"revocation_endpoint"`
-	JwksUri                           string   `json:"jwks_uri"`
+	JwksURI                           string   `json:"jwks_uri"`
 	ResponseTypesSupported            []string `json:"response_types_supported"`
 	SubjectTypesSupported             []string `json:"subject_types_supported"`
-	IdTokenSigningAlgValuesSupported  []string `json:"id_token_signing_alg_values_supported"`
+	IDTokenSigningAlgValuesSupported  []string `json:"id_token_signing_alg_values_supported"`
 	ScopesSupported                   []string `json:"scopes_supported"`
 	TokenEndpointAuthMethodsSupported []string `json:"token_endpoint_auth_methods_supported"`
 	ClaimsSupported                   []string `json:"claims_supported"`
@@ -123,25 +126,29 @@ type oidcIDToken struct {
 	TokenType    string `json:"token_type"`
 	RefreshToken string `json:"refresh_token"`
 	ExpiresIn    int    `json:"expires_in"`
-	IdToken      string `json:"id_token"`
+	IDToken      string `json:"id_token"`
 }
 
 func init() {
 	filters.Register(kind)
 }
 
+// Name returns the name of the OIDCAdaptor filter instance.
 func (o *OIDCAdaptor) Name() string {
 	return o.spec.Name()
 }
 
+// Spec returns the spec used by the OIDCAdaptor instance.
 func (o *OIDCAdaptor) Spec() filters.Spec {
 	return o.spec
 }
 
+// Kind returns the kind of filter.
 func (o *OIDCAdaptor) Kind() *filters.Kind {
 	return kind
 }
 
+// Init initializes the filter.
 func (o *OIDCAdaptor) Init() {
 	// delegate store interface operation to itself for testing
 	o.store = o
@@ -164,11 +171,13 @@ func (o *OIDCAdaptor) Init() {
 	o.redirectPath = parsed.Path
 }
 
+// Inherit inherits previous generation of the filter instance.
 func (o *OIDCAdaptor) Inherit(previousGeneration filters.Filter) {
 	o.Init()
 	previousGeneration.Close()
 }
 
+// Handle handles the request.
 func (o *OIDCAdaptor) Handle(ctx *context.Context) (result string) {
 	req := ctx.GetInputRequest().(*httpprot.Request)
 	var rw *httpprot.Response
@@ -192,16 +201,18 @@ func (o *OIDCAdaptor) Handle(ctx *context.Context) (result string) {
 	if req.Path() == o.redirectPath {
 		return o.handleOIDCCallback(ctx)
 	}
-	authorizeUrl := o.buildAuthorizeURL(req)
+	authorizeURL := o.buildAuthorizeURL(req)
 	rw.SetStatusCode(http.StatusFound)
-	rw.Header().Set("Location", authorizeUrl)
+	rw.Header().Set("Location", authorizeURL)
 	return resultFiltered
 }
 
+// Status returns the status of the filter instance.
 func (o *OIDCAdaptor) Status() interface{} {
 	return nil
 }
 
+// Close closes the filter instance.
 func (o *OIDCAdaptor) Close() {
 }
 
@@ -222,7 +233,7 @@ func (o *OIDCAdaptor) initDiscoveryOIDCConf() {
 			logger.Errorf("parse jwksRefreshInterval[%s] duration error: %s", o.jwksRefreshInterval, err)
 		}
 	}
-	jwks, err := keyfunc.Get(oidcConf.JwksUri, keyfunc.Options{
+	jwks, err := keyfunc.Get(oidcConf.JwksURI, keyfunc.Options{
 		Client:          httpCli,
 		RefreshInterval: interval,
 	})
@@ -251,17 +262,17 @@ func (o *OIDCAdaptor) handleOIDCCallback(ctx *context.Context) string {
 			req.Header().Set("X-Access-Token", oidcToken.AccessToken)
 		}
 	}
-	reqUrl := o.store.get(clusterCacheKey("request_url", state))
-	req.Header().Set("X-Origin-Request-URL", reqUrl)
+	reqURL := o.store.get(clusterCacheKey("request_url", state))
+	req.Header().Set("X-Origin-Request-URL", reqURL)
 
 	userInfo := map[string]any{}
-	if len(oidcToken.IdToken) > 0 {
-		parseToken, err := o.validateIDToken(oidcToken.IdToken)
+	if len(oidcToken.IDToken) > 0 {
+		parseToken, err := o.validateIDToken(oidcToken.IDToken)
 		if err != nil {
 			return filterResp(rw, http.StatusUnauthorized, "invalid oidc id token")
 		}
 		if o.setIDTokenHeader {
-			req.Header().Set("X-ID-Token", oidcToken.IdToken)
+			req.Header().Set("X-ID-Token", oidcToken.IDToken)
 		}
 		if claims, ok := parseToken.Claims.(jwt.MapClaims); ok {
 			userInfo = claims
@@ -285,7 +296,7 @@ func (o *OIDCAdaptor) handleOIDCCallback(ctx *context.Context) string {
 func (o *OIDCAdaptor) fetchOIDCToken(authCode string, state string, spec *Spec, err error, rw *httpprot.Response, req *httpprot.Request) (*oidcIDToken, error) {
 	// client_secret_post || client_secret_basic
 	tokenFormData := url.Values{
-		"client_id":     {o.spec.ClientId},
+		"client_id":     {o.spec.ClientID},
 		"client_secret": {o.spec.ClientSecret},
 		"code":          {authCode},
 		"grant_type":    {"authorization_code"},
@@ -295,7 +306,7 @@ func (o *OIDCAdaptor) fetchOIDCToken(authCode string, state string, spec *Spec,
 	// https://openid.net/specs/openid-connect-core-1_0.html#TokenRequest
 	tokenReq, _ := http.NewRequest(http.MethodPost, o.oidcConfig.TokenEndpoint, strings.NewReader(tokenFormData.Encode()))
 	tokenReq.Header.Set("Content-Type", "application/x-www-form-urlencoded")
-	authBasic := base64.StdEncoding.EncodeToString([]byte(fmt.Sprintf("%s:%s", spec.ClientId, spec.ClientSecret)))
+	authBasic := base64.StdEncoding.EncodeToString([]byte(fmt.Sprintf("%s:%s", spec.ClientID, spec.ClientSecret)))
 	tokenReq.Header.Set("Authorization", "Basic "+authBasic)
 	tokenReq.Header.Set("Accept", "application/json")
 
@@ -360,40 +371,40 @@ func (o *OIDCAdaptor) validateCodeAndState(code, state string) error {
 
 func (o *OIDCAdaptor) buildAuthorizeURL(req *httpprot.Request) string {
 	// https://openid.net/specs/openid-connect-core-1_0.html#AuthorizationEndpoint
-	var authUrlBuilder strings.Builder
-	authUrlBuilder.WriteString(o.oidcConfig.AuthorizationEndpoint)
-	authUrlBuilder.WriteString("?client_id=" + o.spec.ClientId)
+	var authURLBuilder strings.Builder
+	authURLBuilder.WriteString(o.oidcConfig.AuthorizationEndpoint)
+	authURLBuilder.WriteString("?client_id=" + o.spec.ClientID)
 	state := strings.ReplaceAll(uuid.New().String(), "-", "")
 	// state is recommended
-	authUrlBuilder.WriteString("&state=" + state)
+	authURLBuilder.WriteString("&state=" + state)
 	// End-user may spend some time doing login stuff, so we use a 10-minute timeout
 	err := o.store.put(clusterCacheKey("state", state), "1", 10*time.Minute)
 	if err != nil {
 		logger.Errorf("put oidc state error: %s", err)
 	}
-	var reqUrl string
+	var reqURL string
 	args := req.URL().RawQuery
 	if args != "" {
-		reqUrl = fmt.Sprintf("%s://%s%s?%s", req.Scheme(), req.Host(), req.Path(), args)
+		reqURL = fmt.Sprintf("%s://%s%s?%s", req.Scheme(), req.Host(), req.Path(), args)
 	} else {
-		reqUrl = fmt.Sprintf("%s://%s%s", req.Scheme(), req.Host(), req.Path())
+		reqURL = fmt.Sprintf("%s://%s%s", req.Scheme(), req.Host(), req.Path())
 	}
-	err = o.store.put(clusterCacheKey("request_url", state), reqUrl, 10*time.Minute)
+	err = o.store.put(clusterCacheKey("request_url", state), reqURL, 10*time.Minute)
 	if err != nil {
 		logger.Errorf("put origin request url error: %s", err)
 	}
 	// nonce is optional
 	nonce := strings.ReplaceAll(uuid.New().String(), "-", "")
-	authUrlBuilder.WriteString("&nonce=" + nonce)
-	authUrlBuilder.WriteString("&response_type=code")
-	authUrlBuilder.WriteString("&scope=")
+	authURLBuilder.WriteString("&nonce=" + nonce)
+	authURLBuilder.WriteString("&response_type=code")
+	authURLBuilder.WriteString("&scope=")
 	if len(o.oidcConfig.ScopesSupported) > 0 {
-		authUrlBuilder.WriteString(strings.Join(o.oidcConfig.ScopesSupported, "+"))
+		authURLBuilder.WriteString(strings.Join(o.oidcConfig.ScopesSupported, "+"))
 	} else {
-		authUrlBuilder.WriteString("user")
+		authURLBuilder.WriteString("user")
 	}
-	authUrlBuilder.WriteString("&redirect_uri=" + url.QueryEscape(o.spec.RedirectURI))
-	return authUrlBuilder.String()
+	authURLBuilder.WriteString("&redirect_uri=" + url.QueryEscape(o.spec.RedirectURI))
+	return authURLBuilder.String()
 }
 
 func clusterCacheKey(tag string, val string) string {
diff --git a/pkg/filters/opafilter/opafilter.go b/pkg/filters/opafilter/opafilter.go
index 64f6d51ae9..34cf551a96 100644
--- a/pkg/filters/opafilter/opafilter.go
+++ b/pkg/filters/opafilter/opafilter.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package opafilter implements OpenPolicyAgent function.
 package opafilter
 
 import (
@@ -60,12 +61,14 @@ var kind = &filters.Kind{
 	},
 }
 
+// OPAFilter is the filter for OpenPolicyAgent.
 type OPAFilter struct {
 	spec                  *Spec
 	includedHeadersParsed []string `yaml:"includedHeadersParsed"`
 	regoQuery             *rego.PreparedEvalQuery
 }
 
+// Spec is the spec of the OPAFilter.
 type Spec struct {
 	filters.BaseSpec `yaml:",inline"`
 	DefaultStatus    int    `yaml:"defaultStatus"`
@@ -78,18 +81,22 @@ func init() {
 	filters.Register(kind)
 }
 
+// Name returns the name of the OPAFilter filter instance.
 func (o *OPAFilter) Name() string {
 	return o.spec.Name()
 }
 
+// Spec returns the spec of the OPAFilter filter instance.
 func (o *OPAFilter) Spec() filters.Spec {
 	return o.spec
 }
 
+// Kind returns the kind of the OPAFilter filter instance.
 func (o *OPAFilter) Kind() *filters.Kind {
 	return kind
 }
 
+// Init initialize the filter instance.
 func (o *OPAFilter) Init() {
 	o.includedHeadersParsed = strings.Split(o.spec.IncludedHeaders, ",")
 	if o.spec.DefaultStatus == 0 {
@@ -117,11 +124,13 @@ func (o *OPAFilter) Init() {
 	}
 }
 
+// Inherit inherits previous generation of filter instance.
 func (o *OPAFilter) Inherit(previousGeneration filters.Filter) {
 	o.Init()
 	previousGeneration.Close()
 }
 
+// Handle handles the request.
 func (o *OPAFilter) Handle(ctx *context.Context) (result string) {
 	req := ctx.GetInputRequest().(*httpprot.Request)
 	var rw *httpprot.Response
@@ -132,10 +141,12 @@ func (o *OPAFilter) Handle(ctx *context.Context) (result string) {
 	return o.evalRequest(req, rw)
 }
 
+// Status returns the status of the filter instance.
 func (o *OPAFilter) Status() interface{} {
 	return nil
 }
 
+// Close closes the filter instance.
 func (o *OPAFilter) Close() {
 }
 
diff --git a/pkg/filters/proxies/grpcproxy/loadbalance.go b/pkg/filters/proxies/grpcproxy/loadbalance.go
index b8915c8b67..a5656a978c 100644
--- a/pkg/filters/proxies/grpcproxy/loadbalance.go
+++ b/pkg/filters/proxies/grpcproxy/loadbalance.go
@@ -79,5 +79,5 @@ func (f *forwardLoadBalancer) ReturnServer(s *Server, req protocols.Request, res
 }
 
 // Close closes the load balancer.
-func (lb *forwardLoadBalancer) Close() {
+func (f *forwardLoadBalancer) Close() {
 }
diff --git a/pkg/filters/proxies/grpcproxy/proxy.go b/pkg/filters/proxies/grpcproxy/proxy.go
index 0c7e419ede..b2d72c94e1 100644
--- a/pkg/filters/proxies/grpcproxy/proxy.go
+++ b/pkg/filters/proxies/grpcproxy/proxy.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package grpcproxy provides the proxy filter of gRPC.
 package grpcproxy
 
 import (
@@ -84,11 +85,16 @@ type (
 	}
 
 	// Server is the backend server.
-	Server             = proxies.Server
-	RequestMatcher     = proxies.RequestMatcher
-	LoadBalancer       = proxies.LoadBalancer
-	LoadBalanceSpec    = proxies.LoadBalanceSpec
-	BaseServerPool     = proxies.ServerPoolBase
+	Server = proxies.Server
+	// RequestMatcher is the interface of a request matcher
+	RequestMatcher = proxies.RequestMatcher
+	// LoadBalancer is the interface of a load balancer.
+	LoadBalancer = proxies.LoadBalancer
+	// LoadBalanceSpec is the spec of a load balancer.
+	LoadBalanceSpec = proxies.LoadBalanceSpec
+	// BaseServerPool is the base of a server pool.
+	BaseServerPool = proxies.ServerPoolBase
+	// BaseServerPoolSpec is the spec of BaseServerPool.
 	BaseServerPoolSpec = proxies.ServerPoolBaseSpec
 )
 
diff --git a/pkg/filters/proxies/httpproxy/proxy.go b/pkg/filters/proxies/httpproxy/proxy.go
index fb662fb361..19add5812e 100644
--- a/pkg/filters/proxies/httpproxy/proxy.go
+++ b/pkg/filters/proxies/httpproxy/proxy.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package httpproxy provides the Proxy of HTTP.
 package httpproxy
 
 import (
@@ -129,11 +130,16 @@ type (
 	}
 
 	// Server is the backend server.
-	Server             = proxies.Server
-	RequestMatcher     = proxies.RequestMatcher
-	LoadBalancer       = proxies.LoadBalancer
-	LoadBalanceSpec    = proxies.LoadBalanceSpec
-	BaseServerPool     = proxies.ServerPoolBase
+	Server = proxies.Server
+	// RequestMatcher is the interface of a request matcher
+	RequestMatcher = proxies.RequestMatcher
+	// LoadBalancer is the interface of a load balancer.
+	LoadBalancer = proxies.LoadBalancer
+	// LoadBalanceSpec is the spec of a load balancer.
+	LoadBalanceSpec = proxies.LoadBalanceSpec
+	// BaseServerPool is the base of a server pool.
+	BaseServerPool = proxies.ServerPoolBase
+	// BaseServerPoolSpec is the spec of BaseServerPool.
 	BaseServerPoolSpec = proxies.ServerPoolBaseSpec
 )
 
diff --git a/pkg/filters/proxies/serverpool.go b/pkg/filters/proxies/serverpool.go
index 0e41cf1893..05abed5234 100644
--- a/pkg/filters/proxies/serverpool.go
+++ b/pkg/filters/proxies/serverpool.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package proxies provides the common interface and implementation of proxies.
 package proxies
 
 import (
diff --git a/pkg/filters/ratelimiter/ratelimiter.go b/pkg/filters/ratelimiter/ratelimiter.go
index 5381d6f730..92b3893a48 100644
--- a/pkg/filters/ratelimiter/ratelimiter.go
+++ b/pkg/filters/ratelimiter/ratelimiter.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package ratelimiter implements a rate limiter.
 package ratelimiter
 
 import (
diff --git a/pkg/filters/redirector/redirector.go b/pkg/filters/redirector/redirector.go
index ce4a1de355..6e0692687f 100644
--- a/pkg/filters/redirector/redirector.go
+++ b/pkg/filters/redirector/redirector.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package redirector implements a filter to handle HTTP redirects.
 package redirector
 
 import (
@@ -87,6 +88,7 @@ type (
 	}
 )
 
+// Validate validates the spec.
 func (s *Spec) Validate() error {
 	if _, ok := statusCodeMap[s.StatusCode]; !ok {
 		return errors.New("invalid status code of Redirector, support 300, 301, 302, 303, 304, 307, 308")
diff --git a/pkg/filters/remotefilter/remotefilter.go b/pkg/filters/remotefilter/remotefilter.go
index 43135a780b..328136a7e3 100644
--- a/pkg/filters/remotefilter/remotefilter.go
+++ b/pkg/filters/remotefilter/remotefilter.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package remotefilter implements the RemoteFilter filter to invokes remote apis.
 package remotefilter
 
 import (
diff --git a/pkg/filters/topicmapper/topicmapper.go b/pkg/filters/topicmapper/topicmapper.go
index 6e0400a055..572dbc4e96 100644
--- a/pkg/filters/topicmapper/topicmapper.go
+++ b/pkg/filters/topicmapper/topicmapper.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package topicmapper maps MQTT topic to Kafka topics and key-value headers
 package topicmapper
 
 import (
diff --git a/pkg/filters/validator/validator.go b/pkg/filters/validator/validator.go
index 7d10a40914..ab142a98e1 100644
--- a/pkg/filters/validator/validator.go
+++ b/pkg/filters/validator/validator.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package validator provides Validator filter to validates HTTP requests.
 package validator
 
 import (
diff --git a/pkg/filters/wasmhost/doc.go b/pkg/filters/wasmhost/doc.go
index 58f492ae1a..07122cfcf0 100644
--- a/pkg/filters/wasmhost/doc.go
+++ b/pkg/filters/wasmhost/doc.go
@@ -15,4 +15,5 @@
  * limitations under the License.
  */
 
+// Package wasmhost implements a host environment for WebAssembly.
 package wasmhost
diff --git a/pkg/graceupdate/graceupdate.go b/pkg/graceupdate/graceupdate.go
index 09048235e1..a54fe9b0a3 100644
--- a/pkg/graceupdate/graceupdate.go
+++ b/pkg/graceupdate/graceupdate.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package graceupdate provides graceful update for easegress.
 package graceupdate
 
 import (
diff --git a/pkg/logger/logger.go b/pkg/logger/logger.go
index 51cdd1c467..a73284a872 100644
--- a/pkg/logger/logger.go
+++ b/pkg/logger/logger.go
@@ -15,16 +15,18 @@
  * limitations under the License.
  */
 
+// Package logger provides logger for Easegress.
 package logger
 
 import (
-	"github.com/go-logr/zapr"
-	"go.opentelemetry.io/otel"
 	"io"
 	"os"
 	"path/filepath"
 	"time"
 
+	"github.com/go-logr/zapr"
+	"go.opentelemetry.io/otel"
+
 	"go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
 
diff --git a/pkg/object/autocertmanager/autocertmanager.go b/pkg/object/autocertmanager/autocertmanager.go
index ba6151535b..bf6bfea009 100644
--- a/pkg/object/autocertmanager/autocertmanager.go
+++ b/pkg/object/autocertmanager/autocertmanager.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package autocertmanager provides AutoCertManager to manage certificates automatically.
 package autocertmanager
 
 import (
diff --git a/pkg/object/consulserviceregistry/consulserviceregistry.go b/pkg/object/consulserviceregistry/consulserviceregistry.go
index 44b2a83825..1bd8d1493a 100644
--- a/pkg/object/consulserviceregistry/consulserviceregistry.go
+++ b/pkg/object/consulserviceregistry/consulserviceregistry.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package consulserviceregistry provides ConsulServiceRegistry.
 package consulserviceregistry
 
 import (
diff --git a/pkg/object/easemonitormetrics/easemonitormetrics.go b/pkg/object/easemonitormetrics/easemonitormetrics.go
index 45b8d2136f..2f5663e44f 100644
--- a/pkg/object/easemonitormetrics/easemonitormetrics.go
+++ b/pkg/object/easemonitormetrics/easemonitormetrics.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package easemonitormetrics provides EaseMonitorMetrics.
 package easemonitormetrics
 
 import (
diff --git a/pkg/object/etcdserviceregistry/etcdserviceregistry.go b/pkg/object/etcdserviceregistry/etcdserviceregistry.go
index 06b419b56f..dff9504511 100644
--- a/pkg/object/etcdserviceregistry/etcdserviceregistry.go
+++ b/pkg/object/etcdserviceregistry/etcdserviceregistry.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package eserviceregistry provides EtcdServiceRegistry.
 package eserviceregistry
 
 import (
diff --git a/pkg/object/eurekaserviceregistry/eurekaserviceregistry.go b/pkg/object/eurekaserviceregistry/eurekaserviceregistry.go
index de2c3dbf5e..e8afcd1ef1 100644
--- a/pkg/object/eurekaserviceregistry/eurekaserviceregistry.go
+++ b/pkg/object/eurekaserviceregistry/eurekaserviceregistry.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package eurekaserviceregistry provides EurekaServiceRegistry.
 package eurekaserviceregistry
 
 import (
diff --git a/pkg/object/function/faascontroller.go b/pkg/object/function/faascontroller.go
index 21aa94dbf3..bf97d484c0 100644
--- a/pkg/object/function/faascontroller.go
+++ b/pkg/object/function/faascontroller.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package function provides FaasController.
 package function
 
 import (
diff --git a/pkg/object/function/provider/provider.go b/pkg/object/function/provider/provider.go
index cba06c018a..1cdee3c171 100644
--- a/pkg/object/function/provider/provider.go
+++ b/pkg/object/function/provider/provider.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package provider defines and implements FaasProvider interface.
 package provider
 
 import (
diff --git a/pkg/object/function/spec/fsm.go b/pkg/object/function/spec/fsm.go
index 715e3a6163..d563df5837 100644
--- a/pkg/object/function/spec/fsm.go
+++ b/pkg/object/function/spec/fsm.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package spec provides the spec for FaaS.
 package spec
 
 import (
diff --git a/pkg/object/function/storage/storage.go b/pkg/object/function/storage/storage.go
index dc667fd2db..02591b73ae 100644
--- a/pkg/object/function/storage/storage.go
+++ b/pkg/object/function/storage/storage.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package storage provides the storage for FaaS.
 package storage
 
 import (
diff --git a/pkg/object/function/worker/worker.go b/pkg/object/function/worker/worker.go
index 98a79b002f..547cbea15d 100644
--- a/pkg/object/function/worker/worker.go
+++ b/pkg/object/function/worker/worker.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package worker provides the worker for FaaSController.
 package worker
 
 import (
diff --git a/pkg/object/globalfilter/globalfilter.go b/pkg/object/globalfilter/globalfilter.go
index d7d4b6a99c..aee0effd58 100644
--- a/pkg/object/globalfilter/globalfilter.go
+++ b/pkg/object/globalfilter/globalfilter.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package globalfilter provides GlobalFilter.
 package globalfilter
 
 import (
diff --git a/pkg/object/grpcserver/grpcserver.go b/pkg/object/grpcserver/grpcserver.go
index 5f0a0f3dbb..5562d7e2fd 100644
--- a/pkg/object/grpcserver/grpcserver.go
+++ b/pkg/object/grpcserver/grpcserver.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package grpcserver implements the GRPCServer.
 package grpcserver
 
 import (
diff --git a/pkg/object/httpserver/httpserver.go b/pkg/object/httpserver/httpserver.go
index 0bf087b4f8..1651e42aec 100644
--- a/pkg/object/httpserver/httpserver.go
+++ b/pkg/object/httpserver/httpserver.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package httpserver implements the HTTPServer.
 package httpserver
 
 import (
diff --git a/pkg/object/httpserver/routers/ordered/router.go b/pkg/object/httpserver/routers/ordered/router.go
index 51ef70b628..04f5e349bf 100644
--- a/pkg/object/httpserver/routers/ordered/router.go
+++ b/pkg/object/httpserver/routers/ordered/router.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package ordered provides the router implementation of ordered routing policy.
 package ordered
 
 import (
diff --git a/pkg/object/httpserver/routers/radixtree/router.go b/pkg/object/httpserver/routers/radixtree/router.go
index fe317e9de9..c882bbc55b 100644
--- a/pkg/object/httpserver/routers/radixtree/router.go
+++ b/pkg/object/httpserver/routers/radixtree/router.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package radixtree provides the router implementation of radix tree routing policy.
 package radixtree
 
 import (
diff --git a/pkg/object/httpserver/routers/routers.go b/pkg/object/httpserver/routers/routers.go
index 1fb7c529be..d91376e5c9 100644
--- a/pkg/object/httpserver/routers/routers.go
+++ b/pkg/object/httpserver/routers/routers.go
@@ -15,6 +15,8 @@
  * limitations under the License.
  */
 
+// Package routers provides the router interface and the implementation of
+// different routing policies.
 package routers
 
 import (
diff --git a/pkg/object/ingresscontroller/ingresscontroller.go b/pkg/object/ingresscontroller/ingresscontroller.go
index 1d416c7988..34def5cb4a 100644
--- a/pkg/object/ingresscontroller/ingresscontroller.go
+++ b/pkg/object/ingresscontroller/ingresscontroller.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package ingresscontroller implements a K8s ingress controller.
 package ingresscontroller
 
 import (
diff --git a/pkg/object/meshcontroller/api/api.go b/pkg/object/meshcontroller/api/api.go
index 27788fcc57..32f6b8e255 100644
--- a/pkg/object/meshcontroller/api/api.go
+++ b/pkg/object/meshcontroller/api/api.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package api provides the API for mesh controller.
 package api
 
 import (
diff --git a/pkg/object/meshcontroller/certmanager/certmanager.go b/pkg/object/meshcontroller/certmanager/certmanager.go
index 235d4c1b88..cfd7564bb2 100644
--- a/pkg/object/meshcontroller/certmanager/certmanager.go
+++ b/pkg/object/meshcontroller/certmanager/certmanager.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package certmanager provides the cert manager for mesh controller.
 package certmanager
 
 import (
diff --git a/pkg/object/meshcontroller/informer/informer.go b/pkg/object/meshcontroller/informer/informer.go
index c08c9b166d..ae8d624b56 100644
--- a/pkg/object/meshcontroller/informer/informer.go
+++ b/pkg/object/meshcontroller/informer/informer.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package informer provides the informer for mesh controller.
 package informer
 
 import (
diff --git a/pkg/object/meshcontroller/ingresscontroller/ingresscontroller.go b/pkg/object/meshcontroller/ingresscontroller/ingresscontroller.go
index b025655441..b70f1b8e0b 100644
--- a/pkg/object/meshcontroller/ingresscontroller/ingresscontroller.go
+++ b/pkg/object/meshcontroller/ingresscontroller/ingresscontroller.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package ingresscontroller implements the ingress controller for service mesh.
 package ingresscontroller
 
 import (
diff --git a/pkg/object/meshcontroller/label/label.go b/pkg/object/meshcontroller/label/label.go
index 693076ba0d..11da5615a4 100644
--- a/pkg/object/meshcontroller/label/label.go
+++ b/pkg/object/meshcontroller/label/label.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package label defines labels.
 package label
 
 const (
diff --git a/pkg/object/meshcontroller/layout/layout.go b/pkg/object/meshcontroller/layout/layout.go
index c7f159bc3b..02ee08fd2b 100644
--- a/pkg/object/meshcontroller/layout/layout.go
+++ b/pkg/object/meshcontroller/layout/layout.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package layout defines the layout of the data in etcd.
 package layout
 
 import (
diff --git a/pkg/object/meshcontroller/master/master.go b/pkg/object/meshcontroller/master/master.go
index dff6ee22f9..c7af28ed7f 100644
--- a/pkg/object/meshcontroller/master/master.go
+++ b/pkg/object/meshcontroller/master/master.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package master provides master role of Easegress for mesh control plane.
 package master
 
 import (
diff --git a/pkg/object/meshcontroller/meshcontroller.go b/pkg/object/meshcontroller/meshcontroller.go
index 3df1e56068..1df7ed3db0 100644
--- a/pkg/object/meshcontroller/meshcontroller.go
+++ b/pkg/object/meshcontroller/meshcontroller.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package meshcontroller provides the service mesh controller.
 package meshcontroller
 
 import (
diff --git a/pkg/object/meshcontroller/registrycenter/registrycenter.go b/pkg/object/meshcontroller/registrycenter/registrycenter.go
index c90c960af1..e5f4c17ee9 100644
--- a/pkg/object/meshcontroller/registrycenter/registrycenter.go
+++ b/pkg/object/meshcontroller/registrycenter/registrycenter.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package registrycenter provides registry center server.
 package registrycenter
 
 import (
diff --git a/pkg/object/meshcontroller/service/service.go b/pkg/object/meshcontroller/service/service.go
index 9d91cf33eb..ab9031f7cb 100644
--- a/pkg/object/meshcontroller/service/service.go
+++ b/pkg/object/meshcontroller/service/service.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package service provides business layer between mesh and store.
 package service
 
 import (
diff --git a/pkg/object/meshcontroller/spec/spec.go b/pkg/object/meshcontroller/spec/spec.go
index ff8c4c93ef..1656456d28 100644
--- a/pkg/object/meshcontroller/spec/spec.go
+++ b/pkg/object/meshcontroller/spec/spec.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package spec defines the spec for various objects in mesh.
 package spec
 
 import (
diff --git a/pkg/object/meshcontroller/storage/storage.go b/pkg/object/meshcontroller/storage/storage.go
index 66e19072d9..dba46d9158 100644
--- a/pkg/object/meshcontroller/storage/storage.go
+++ b/pkg/object/meshcontroller/storage/storage.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package storage provides the storage APIs.
 package storage
 
 import (
diff --git a/pkg/object/meshcontroller/worker/worker.go b/pkg/object/meshcontroller/worker/worker.go
index 6e3ffe9673..5a7b824ed0 100644
--- a/pkg/object/meshcontroller/worker/worker.go
+++ b/pkg/object/meshcontroller/worker/worker.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package worker provides the worker for mesh controller.
 package worker
 
 import (
diff --git a/pkg/object/mqttproxy/mqttproxy.go b/pkg/object/mqttproxy/mqttproxy.go
index 22a323712f..67ea50d3a4 100644
--- a/pkg/object/mqttproxy/mqttproxy.go
+++ b/pkg/object/mqttproxy/mqttproxy.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package mqttproxy implements the MQTTProxy.
 package mqttproxy
 
 import (
diff --git a/pkg/object/mqttproxy/topicmgr.go b/pkg/object/mqttproxy/topicmgr.go
index ddf6868f19..f73b44cccb 100644
--- a/pkg/object/mqttproxy/topicmgr.go
+++ b/pkg/object/mqttproxy/topicmgr.go
@@ -25,6 +25,7 @@ import (
 	lru "github.com/hashicorp/golang-lru"
 )
 
+// TopicManager is the interface of a topic manager.
 type TopicManager interface {
 	subscribe(topics []string, qoss []byte, clientID string) error
 	unsubscribe(topics []string, clientID string) error
diff --git a/pkg/object/nacosserviceregistry/nacosserviceregistry.go b/pkg/object/nacosserviceregistry/nacosserviceregistry.go
index bcbda9e1a5..1b6e3db34f 100644
--- a/pkg/object/nacosserviceregistry/nacosserviceregistry.go
+++ b/pkg/object/nacosserviceregistry/nacosserviceregistry.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package nacosserviceregistry provides the NacosServiceRegistry.
 package nacosserviceregistry
 
 import (
diff --git a/pkg/object/pipeline/pipeline.go b/pkg/object/pipeline/pipeline.go
index 75c227eee2..5d901f87e4 100644
--- a/pkg/object/pipeline/pipeline.go
+++ b/pkg/object/pipeline/pipeline.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package pipeline provides the pipeline of Easegress.
 package pipeline
 
 import (
diff --git a/pkg/object/rawconfigtrafficcontroller/rawconfigtrafficcontroller.go b/pkg/object/rawconfigtrafficcontroller/rawconfigtrafficcontroller.go
index 8e1037dfad..e013370393 100644
--- a/pkg/object/rawconfigtrafficcontroller/rawconfigtrafficcontroller.go
+++ b/pkg/object/rawconfigtrafficcontroller/rawconfigtrafficcontroller.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package rawconfigtrafficcontroller implements the RawConfigTrafficController.
 package rawconfigtrafficcontroller
 
 import (
diff --git a/pkg/object/serviceregistry/serviceregistry.go b/pkg/object/serviceregistry/serviceregistry.go
index 94d56ea634..8e617ed46b 100644
--- a/pkg/object/serviceregistry/serviceregistry.go
+++ b/pkg/object/serviceregistry/serviceregistry.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package serviceregistry provides the service registry.
 package serviceregistry
 
 import (
diff --git a/pkg/object/statussynccontroller/statussynccontroller.go b/pkg/object/statussynccontroller/statussynccontroller.go
index 7202672d24..b9b0431863 100644
--- a/pkg/object/statussynccontroller/statussynccontroller.go
+++ b/pkg/object/statussynccontroller/statussynccontroller.go
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+// Package statussynccontroller implements the StatusSyncController.
 package statussynccontroller
 
 import (
diff --git a/pkg/object/trafficcontroller/trafficcontroller.go b/pkg/object/trafficcontroller/trafficcontroller.go
index 6c1ed6720b..685b605571 100644
--- a/pkg/object/trafficcontroller/trafficcontroller.go
+++ b/pkg/object/trafficcontroller/trafficcontroller.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package trafficcontroller implements the TrafficController.
 package trafficcontroller
 
 import (
diff --git a/pkg/object/zookeeperserviceregistry/zookeeperserviceregistry.go b/pkg/object/zookeeperserviceregistry/zookeeperserviceregistry.go
index 7332facbaa..9c765e1888 100644
--- a/pkg/object/zookeeperserviceregistry/zookeeperserviceregistry.go
+++ b/pkg/object/zookeeperserviceregistry/zookeeperserviceregistry.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package zookeeperserviceregistry implements the ZookeeperServiceRegistry.
 package zookeeperserviceregistry
 
 import (
diff --git a/pkg/option/option.go b/pkg/option/option.go
index 3f7941f477..dd61ecb7a6 100644
--- a/pkg/option/option.go
+++ b/pkg/option/option.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package option implements the start-up options.
 package option
 
 import (
diff --git a/pkg/pidfile/pidfile.go b/pkg/pidfile/pidfile.go
index c9432b7f4a..f042702a1e 100644
--- a/pkg/pidfile/pidfile.go
+++ b/pkg/pidfile/pidfile.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package pidfile provides pidfile related functions.
 package pidfile
 
 import (
diff --git a/pkg/profile/profile.go b/pkg/profile/profile.go
index 88274502a8..61a606e80d 100644
--- a/pkg/profile/profile.go
+++ b/pkg/profile/profile.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package profile provides profile related functions.
 package profile
 
 import (
diff --git a/pkg/protocols/grpcprot/fake.go b/pkg/protocols/grpcprot/fake.go
index 644186a176..0978a25f73 100644
--- a/pkg/protocols/grpcprot/fake.go
+++ b/pkg/protocols/grpcprot/fake.go
@@ -19,18 +19,22 @@ package grpcprot
 
 import (
 	"context"
+
 	"google.golang.org/grpc"
 )
 
+// FakeServerStream is a fake grpc.ServerStream for testing.
 type FakeServerStream struct {
 	grpc.ServerStream
 	ctx context.Context
 }
 
+// NewFakeServerStream returns a new FakeServerStream.
 func NewFakeServerStream(ctx context.Context) *FakeServerStream {
 	return &FakeServerStream{ctx: ctx}
 }
 
+// Context returns the context of the stream.
 func (f *FakeServerStream) Context() context.Context {
 	return f.ctx
 }
diff --git a/pkg/protocols/grpcprot/grpc.go b/pkg/protocols/grpcprot/grpc.go
index bfe9280b42..658f1e1075 100644
--- a/pkg/protocols/grpcprot/grpc.go
+++ b/pkg/protocols/grpcprot/grpc.go
@@ -15,10 +15,12 @@
  * limitations under the License.
  */
 
+// Package grpcprot implements the grpc protocol.
 package grpcprot
 
 import (
 	"fmt"
+
 	"github.com/megaease/easegress/pkg/protocols"
 	"google.golang.org/grpc"
 )
@@ -29,30 +31,36 @@ type Protocol struct {
 
 var _ protocols.Protocol = (*Protocol)(nil)
 
+// CreateRequest creates a Request.
 func (p *Protocol) CreateRequest(req interface{}) (protocols.Request, error) {
-	if r, ok := req.(grpc.ServerStream); ok {
+	r, ok := req.(grpc.ServerStream)
+	if ok {
 		return NewRequestWithServerStream(r), nil
-	} else {
-		return nil, fmt.Errorf("input param's type should be grpc.ServerStream")
 	}
+	return nil, fmt.Errorf("input param's type should be grpc.ServerStream")
 }
 
+// CreateResponse creates a Response.
 func (p *Protocol) CreateResponse(resp interface{}) (protocols.Response, error) {
 	return NewResponse(), nil
 }
 
+// NewRequestInfo creates a RequestInfo.
 func (p *Protocol) NewRequestInfo() interface{} {
 	panic("implement me")
 }
 
+// BuildRequest builds a Request from request info.
 func (p *Protocol) BuildRequest(reqInfo interface{}) (protocols.Request, error) {
 	panic("implement me")
 }
 
+// NewResponseInfo creates a ResponseInfo.
 func (p *Protocol) NewResponseInfo() interface{} {
 	panic("implement me")
 }
 
+// BuildResponse builds a Response from response info.
 func (p *Protocol) BuildResponse(respInfo interface{}) (protocols.Response, error) {
 	panic("implement me")
 }
diff --git a/pkg/protocols/grpcprot/header.go b/pkg/protocols/grpcprot/header.go
index 9ca6a65426..ca3739c522 100644
--- a/pkg/protocols/grpcprot/header.go
+++ b/pkg/protocols/grpcprot/header.go
@@ -33,26 +33,31 @@ type (
 	Trailer = Header
 )
 
+// NewHeader returns a new Header
 func NewHeader(md metadata.MD) *Header {
 	return &Header{
 		md: md.Copy(),
 	}
 }
 
+// NewTrailer returns a new Trailer
 func NewTrailer(md metadata.MD) *Trailer {
 	return &Trailer{
 		md: md.Copy(),
 	}
 }
 
+// GetMD returns the metadata.MD
 func (h *Header) GetMD() metadata.MD {
 	return h.md.Copy()
 }
 
+// RawAdd adds the key, value pair to the header.
 func (h *Header) RawAdd(key string, values ...string) {
 	h.md.Append(key, values...)
 }
 
+// Add adds the key, value pair to the header.
 func (h *Header) Add(key string, value interface{}) {
 	switch value.(type) {
 	case string:
@@ -64,10 +69,12 @@ func (h *Header) Add(key string, value interface{}) {
 	}
 }
 
+// RawSet sets the header entries associated with key to the given value.
 func (h *Header) RawSet(key string, values ...string) {
 	h.md.Set(key, values...)
 }
 
+// Set sets the header entries associated with key to the given value.
 func (h *Header) Set(key string, value interface{}) {
 	switch value.(type) {
 	case string:
@@ -79,14 +86,17 @@ func (h *Header) Set(key string, value interface{}) {
 	}
 }
 
+// RawGet gets the values associated with the given key.
 func (h *Header) RawGet(key string) []string {
 	return h.md.Get(key)
 }
 
+// Get gets the values associated with the given key.
 func (h *Header) Get(key string) interface{} {
 	return h.md.Get(key)
 }
 
+// Del deletes the values associated with key.
 func (h *Header) Del(key string) {
 	h.md.Delete(key)
 }
@@ -118,6 +128,7 @@ func (h *Header) Walk(fn func(key string, value interface{}) bool) {
 	}
 }
 
+// Clone returns a copy of the header.
 func (h *Header) Clone() protocols.Header {
 	return &Header{
 		md: h.md.Copy(),
diff --git a/pkg/protocols/grpcprot/request.go b/pkg/protocols/grpcprot/request.go
index af5746299b..5c3b4b88a0 100644
--- a/pkg/protocols/grpcprot/request.go
+++ b/pkg/protocols/grpcprot/request.go
@@ -60,6 +60,7 @@ type (
 )
 
 const (
+	// Authority is the key of authority in grpc metadata
 	Authority = ":authority"
 )
 
@@ -109,6 +110,7 @@ func NewRequestWithContext(ctx context.Context) *Request {
 	return r
 }
 
+// Network returns the network type of the address.
 func (a *Addr) Network() string {
 	if a != nil {
 		// Per the documentation on net/http.Request.RemoteAddr, if this is
@@ -125,6 +127,7 @@ func (a *Addr) Network() string {
 	return ""
 }
 
+// String implements the Stringer interface.
 func (a *Addr) String() string { return a.addr }
 
 func (a *Addr) setAddr(addr string) {
@@ -247,6 +250,7 @@ func (r *Request) RealIP() string {
 	return ip
 }
 
+// SetRealIP set the client ip of the request.
 func (r *Request) SetRealIP(ip string) {
 	r.realIP = ""
 	if strings.ContainsRune(r.peer.Addr.String(), ':') {
@@ -262,6 +266,7 @@ func (r *Request) SourceHost() string {
 	return r.peer.Addr.(*Addr).String()
 }
 
+// SetSourceHost set the source host of the request.
 func (r *Request) SetSourceHost(sourceHost string) {
 	r.peer.Addr.(*Addr).setAddr(sourceHost)
 }
@@ -272,6 +277,7 @@ func (r *Request) Host() string {
 	return r.header.GetFirst(Authority)
 }
 
+// SetHost set the host of the request.
 func (r *Request) SetHost(host string) {
 	r.header.Set(Authority, host)
 }
diff --git a/pkg/protocols/grpcprot/response.go b/pkg/protocols/grpcprot/response.go
index 38bd59e42e..4c53efc9ed 100644
--- a/pkg/protocols/grpcprot/response.go
+++ b/pkg/protocols/grpcprot/response.go
@@ -18,11 +18,12 @@
 package grpcprot
 
 import (
+	"io"
+
 	"github.com/megaease/easegress/pkg/protocols"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/metadata"
 	"google.golang.org/grpc/status"
-	"io"
 )
 
 // Response wrapper status.Status
@@ -38,6 +39,7 @@ var (
 	_ protocols.Response = (*Response)(nil)
 )
 
+// NewResponse returns a new Response.
 func NewResponse() *Response {
 	return &Response{
 		Status:  nil,
@@ -46,22 +48,27 @@ func NewResponse() *Response {
 	}
 }
 
+// SetTrailer sets the trailer of the response.
 func (r *Response) SetTrailer(trailer *Trailer) {
 	r.trailer.md = trailer.md
 }
 
+// Trailer returns the trailer of the response.
 func (r *Response) Trailer() protocols.Trailer {
 	return r.trailer
 }
 
+// RawTrailer returns the trailer of the response.
 func (r *Response) RawTrailer() *Trailer {
 	return r.trailer
 }
 
+// GetStatus returns the status of the response.
 func (r *Response) GetStatus() *status.Status {
 	return r.Status
 }
 
+// SetStatus sets the status of the response.
 func (r *Response) SetStatus(s *status.Status) {
 	if s == nil {
 		r.Status = status.New(codes.OK, "OK")
@@ -70,6 +77,7 @@ func (r *Response) SetStatus(s *status.Status) {
 	r.Status = s
 }
 
+// StatusCode returns the status code of the response.
 func (r *Response) StatusCode() int {
 	if r.Status == nil {
 		return int(codes.OK)
@@ -77,10 +85,12 @@ func (r *Response) StatusCode() int {
 	return int(r.Status.Code())
 }
 
+// SetHeader sets the header of the response.
 func (r *Response) SetHeader(header *Header) {
 	r.header.md = header.md
 }
 
+// Header returns the header of the response.
 func (r *Response) Header() protocols.Header {
 	return r.header
 }
@@ -90,30 +100,37 @@ func (r *Response) RawHeader() *Header {
 	return r.header
 }
 
+// IsStream returns true if the response is a stream.
 func (r *Response) IsStream() bool {
 	return true
 }
 
+// SetPayload sets the payload of the response.
 func (r *Response) SetPayload(payload interface{}) {
 	panic("implement me")
 }
 
+// GetPayload returns the payload of the response.
 func (r *Response) GetPayload() io.Reader {
 	panic("implement me")
 }
 
+// RawPayload returns the payload of the response.
 func (r *Response) RawPayload() []byte {
 	panic("implement me")
 }
 
+// PayloadSize returns the size of the payload.
 func (r *Response) PayloadSize() int64 {
 	panic("implement me")
 }
 
+// ToBuilderResponse wraps the response and returns the wrapper, the
+// return value can be used in the template of the Builder filters.
 func (r *Response) ToBuilderResponse(name string) interface{} {
 	panic("implement me")
 }
 
+// Close closes the response.
 func (r *Response) Close() {
-
 }
diff --git a/pkg/protocols/httpprot/http.go b/pkg/protocols/httpprot/http.go
index 4c3868b1c5..21be73e534 100644
--- a/pkg/protocols/httpprot/http.go
+++ b/pkg/protocols/httpprot/http.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package httpprot implements the HTTP protocol.
 package httpprot
 
 import (
diff --git a/pkg/protocols/httpprot/httpheader/httpheader.go b/pkg/protocols/httpprot/httpheader/httpheader.go
index fb03688818..140d7d0613 100644
--- a/pkg/protocols/httpprot/httpheader/httpheader.go
+++ b/pkg/protocols/httpprot/httpheader/httpheader.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package httpheader provides HTTP Header related functions.
 package httpheader
 
 import (
diff --git a/pkg/protocols/httpprot/httpstat/httpstat.go b/pkg/protocols/httpprot/httpstat/httpstat.go
index 126d8f36a7..066e1e6417 100644
--- a/pkg/protocols/httpprot/httpstat/httpstat.go
+++ b/pkg/protocols/httpprot/httpstat/httpstat.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package httpstat implements the statistics tool for HTTP traffic.
 package httpstat
 
 import (
diff --git a/pkg/protocols/httpprot/response.go b/pkg/protocols/httpprot/response.go
index 99b66e12d3..7be79b53b0 100644
--- a/pkg/protocols/httpprot/response.go
+++ b/pkg/protocols/httpprot/response.go
@@ -71,6 +71,7 @@ func (r *Response) IsStream() bool {
 	return r.stream != nil
 }
 
+// Trailer returns the trailer of the response in type protocols.Trailer.
 func (r *Response) Trailer() protocols.Trailer {
 	return newHeader(r.Std().Trailer)
 }
diff --git a/pkg/protocols/mqttprot/mqtt.go b/pkg/protocols/mqttprot/mqtt.go
index e647fd7610..4001c1cf1f 100644
--- a/pkg/protocols/mqttprot/mqtt.go
+++ b/pkg/protocols/mqttprot/mqtt.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package mqttprot implements the MQTT protocol.
 package mqttprot
 
 import "github.com/megaease/easegress/pkg/protocols"
diff --git a/pkg/protocols/mqttprot/response.go b/pkg/protocols/mqttprot/response.go
index bd4cff56e9..c73494a8ac 100644
--- a/pkg/protocols/mqttprot/response.go
+++ b/pkg/protocols/mqttprot/response.go
@@ -45,6 +45,7 @@ func (r *Response) IsStream() bool {
 	return false
 }
 
+// Trailer returns the trailer of the response.
 func (r *Response) Trailer() protocols.Trailer {
 	panic("implement me")
 }
diff --git a/pkg/protocols/protocols.go b/pkg/protocols/protocols.go
index 642120920e..3b9560ab30 100644
--- a/pkg/protocols/protocols.go
+++ b/pkg/protocols/protocols.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package protocols defines the common interface of protocols used in Easegress.
 package protocols
 
 import (
@@ -135,6 +136,7 @@ type Header interface {
 	Clone() Header
 }
 
+// Trailer is the trailers of a request or response.
 type Trailer = Header
 
 // Protocol is the interface of a protocol.
diff --git a/pkg/registry/registry.go b/pkg/registry/registry.go
index e3b6bcc14d..7fca686c1e 100644
--- a/pkg/registry/registry.go
+++ b/pkg/registry/registry.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package registry is the registry of filters and objects in Easegress.
 package registry
 
 import (
@@ -61,6 +62,7 @@ import (
 	_ "github.com/megaease/easegress/pkg/object/trafficcontroller"
 	_ "github.com/megaease/easegress/pkg/object/zookeeperserviceregistry"
 
+	// Routers
 	_ "github.com/megaease/easegress/pkg/object/httpserver/routers/ordered"
 	_ "github.com/megaease/easegress/pkg/object/httpserver/routers/radixtree"
 )
diff --git a/pkg/resilience/resilience.go b/pkg/resilience/resilience.go
index 991a8977f6..a742e6814a 100644
--- a/pkg/resilience/resilience.go
+++ b/pkg/resilience/resilience.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package resilience implements the resilience policies.
 package resilience
 
 import (
diff --git a/pkg/supervisor/supervisor.go b/pkg/supervisor/supervisor.go
index 56ab1b7898..1ebc890a3e 100644
--- a/pkg/supervisor/supervisor.go
+++ b/pkg/supervisor/supervisor.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package supervisor implements the supervisor of all objects.
 package supervisor
 
 import (
diff --git a/pkg/tracing/tracing.go b/pkg/tracing/tracing.go
index fae5e85eb7..2aee152a64 100644
--- a/pkg/tracing/tracing.go
+++ b/pkg/tracing/tracing.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package tracing implements the tracing.
 package tracing
 
 import (
diff --git a/pkg/util/circuitbreaker/circuitbreaker.go b/pkg/util/circuitbreaker/circuitbreaker.go
index cde849391e..d04965033b 100644
--- a/pkg/util/circuitbreaker/circuitbreaker.go
+++ b/pkg/util/circuitbreaker/circuitbreaker.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package circuitbreaker implements the circuit breaker logic.
 package circuitbreaker
 
 import (
diff --git a/pkg/util/codecounter/codecounter.go b/pkg/util/codecounter/codecounter.go
index c73fb35f80..bdd5d7012b 100644
--- a/pkg/util/codecounter/codecounter.go
+++ b/pkg/util/codecounter/codecounter.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package codecounter provides a goroutine unsafe HTTP status code counter.
 package codecounter
 
 import "sync/atomic"
diff --git a/pkg/util/codectool/codectool.go b/pkg/util/codectool/codectool.go
index 39c147f2cf..4d6bedbfe6 100644
--- a/pkg/util/codectool/codectool.go
+++ b/pkg/util/codectool/codectool.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package codectool provides some codec tools for JSON and YAML marshaling.
 package codectool
 
 import (
diff --git a/pkg/util/dynamicobject/dynamicobject.go b/pkg/util/dynamicobject/dynamicobject.go
index c3e5727e40..16deb82dbd 100644
--- a/pkg/util/dynamicobject/dynamicobject.go
+++ b/pkg/util/dynamicobject/dynamicobject.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package dynamicobject provides a dynamic object.
 package dynamicobject
 
 // DynamicObject defines a dynamic object which is a map of string to
diff --git a/pkg/util/easemonitor/easemonitor.go b/pkg/util/easemonitor/easemonitor.go
index 512230a30a..a17cb700c1 100644
--- a/pkg/util/easemonitor/easemonitor.go
+++ b/pkg/util/easemonitor/easemonitor.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package easemonitor provides the common fields and interfaces for EaseMonitor metrics.
 package easemonitor
 
 import (
diff --git a/pkg/util/fasttime/fasttime.go b/pkg/util/fasttime/fasttime.go
index 043719f64f..f46536434d 100644
--- a/pkg/util/fasttime/fasttime.go
+++ b/pkg/util/fasttime/fasttime.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package fasttime provides fast time.Now() and time.Since() and time.Format().
 package fasttime
 
 import (
diff --git a/pkg/util/filterwriter/filterwriter.go b/pkg/util/filterwriter/filterwriter.go
index ec05b87b8b..91352e8e61 100644
--- a/pkg/util/filterwriter/filterwriter.go
+++ b/pkg/util/filterwriter/filterwriter.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package filterwriter provides a filter writer.
 package filterwriter
 
 import (
diff --git a/pkg/util/ipfilter/ipfilter.go b/pkg/util/ipfilter/ipfilter.go
index 4cb18b52dd..d35644ec12 100644
--- a/pkg/util/ipfilter/ipfilter.go
+++ b/pkg/util/ipfilter/ipfilter.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package ipfilter provides IPFilter.
 package ipfilter
 
 import (
diff --git a/pkg/util/jmxtool/common.go b/pkg/util/jmxtool/common.go
index 068a7d7d3f..18d81400eb 100644
--- a/pkg/util/jmxtool/common.go
+++ b/pkg/util/jmxtool/common.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package jmxtool provides some tools for jmx
 package jmxtool
 
 import (
diff --git a/pkg/util/k8s/k8s.go b/pkg/util/k8s/k8s.go
index 4500bab9fc..8c7dccef8f 100644
--- a/pkg/util/k8s/k8s.go
+++ b/pkg/util/k8s/k8s.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package k8s provides kubernetes utilities.
 package k8s
 
 import (
diff --git a/pkg/util/limitlistener/limitlistener.go b/pkg/util/limitlistener/limitlistener.go
index b91aad1c6e..d003239759 100644
--- a/pkg/util/limitlistener/limitlistener.go
+++ b/pkg/util/limitlistener/limitlistener.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package limitlistener provides a Listener that accepts at most n simultaneous.
 package limitlistener
 
 import (
diff --git a/pkg/util/pathadaptor/pathadaptor.go b/pkg/util/pathadaptor/pathadaptor.go
index 1a55950550..66c11e4b51 100644
--- a/pkg/util/pathadaptor/pathadaptor.go
+++ b/pkg/util/pathadaptor/pathadaptor.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package pathadaptor provides a path adaptor.
 package pathadaptor
 
 import (
diff --git a/pkg/util/prometheushelper/helper.go b/pkg/util/prometheushelper/helper.go
index d96cc1b9cb..1a22b16ec1 100644
--- a/pkg/util/prometheushelper/helper.go
+++ b/pkg/util/prometheushelper/helper.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package prometheushelper provides helper functions for prometheus.
 package prometheushelper
 
 import (
diff --git a/pkg/util/ratelimiter/ratelimiter.go b/pkg/util/ratelimiter/ratelimiter.go
index 2650c72da0..71d7d488a6 100644
--- a/pkg/util/ratelimiter/ratelimiter.go
+++ b/pkg/util/ratelimiter/ratelimiter.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package ratelimiter provides a rate limiter
 package ratelimiter
 
 import (
diff --git a/pkg/util/readers/readerat.go b/pkg/util/readers/readerat.go
index 798d95d1db..b6af28b63b 100644
--- a/pkg/util/readers/readerat.go
+++ b/pkg/util/readers/readerat.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package readers provides several readers.
 package readers
 
 import (
diff --git a/pkg/util/sampler/sampler.go b/pkg/util/sampler/sampler.go
index 47289d39b6..d80fde2c42 100644
--- a/pkg/util/sampler/sampler.go
+++ b/pkg/util/sampler/sampler.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package sampler provides utilities for sampling.
 package sampler
 
 import (
diff --git a/pkg/util/sem/semaphore.go b/pkg/util/sem/semaphore.go
index 5e1a9f989f..a70eca4c12 100644
--- a/pkg/util/sem/semaphore.go
+++ b/pkg/util/sem/semaphore.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package sem provides a semaphore with a max capacity.
 package sem
 
 import (
diff --git a/pkg/util/signer/signer.go b/pkg/util/signer/signer.go
index 96261c6e87..cb502806f6 100644
--- a/pkg/util/signer/signer.go
+++ b/pkg/util/signer/signer.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package signer provides a signer for HTTP requests.
 package signer
 
 import (
diff --git a/pkg/util/stringtool/stringtool.go b/pkg/util/stringtool/stringtool.go
index 5ea60d506e..e0ec90b332 100644
--- a/pkg/util/stringtool/stringtool.go
+++ b/pkg/util/stringtool/stringtool.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package stringtool provides string utilities.
 package stringtool
 
 import (
@@ -127,6 +128,7 @@ func (sm *StringMatcher) Validate() error {
 	return fmt.Errorf("all patterns are empty")
 }
 
+// Init initializes the StringMatcher.
 func (sm *StringMatcher) Init() {
 	if sm.RegEx != "" {
 		sm.re = regexp.MustCompile(sm.RegEx)
diff --git a/pkg/util/timetool/distributedtimer.go b/pkg/util/timetool/distributedtimer.go
index 753959d897..f77d5e0b99 100644
--- a/pkg/util/timetool/distributedtimer.go
+++ b/pkg/util/timetool/distributedtimer.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package timetool provides time utilities.
 package timetool
 
 import (
diff --git a/pkg/util/urlclusteranalyzer/urlclusteranalyzer.go b/pkg/util/urlclusteranalyzer/urlclusteranalyzer.go
index 5186dd9a1e..e81975fd0c 100644
--- a/pkg/util/urlclusteranalyzer/urlclusteranalyzer.go
+++ b/pkg/util/urlclusteranalyzer/urlclusteranalyzer.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package urlclusteranalyzer provides url cluster analyzer.
 package urlclusteranalyzer
 
 import (
diff --git a/pkg/util/urlrule/urlrule.go b/pkg/util/urlrule/urlrule.go
index 310c3880e5..8aee11dc5a 100644
--- a/pkg/util/urlrule/urlrule.go
+++ b/pkg/util/urlrule/urlrule.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package urlrule impelments match rule for HTTP requests.
 package urlrule
 
 import (
diff --git a/pkg/v/v.go b/pkg/v/v.go
index 47c991dfd4..60a5aa87c3 100644
--- a/pkg/v/v.go
+++ b/pkg/v/v.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package v implements the common validation logic of Easegress.
 package v
 
 import (
diff --git a/pkg/version/version.go b/pkg/version/version.go
index b7b4b2ac7c..87e4680016 100644
--- a/pkg/version/version.go
+++ b/pkg/version/version.go
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+// Package version defines the version of Easegress.
 package version
 
 import "fmt"