diff --git a/credentials/credential.go b/credentials/credential.go
index 5ad2871..2ab96f3 100644
--- a/credentials/credential.go
+++ b/credentials/credential.go
@@ -12,9 +12,9 @@ import (
 
 	"github.com/alibabacloud-go/debug/debug"
 	"github.com/alibabacloud-go/tea/tea"
+	"github.com/aliyun/credentials-go/credentials/internal/utils"
 	"github.com/aliyun/credentials-go/credentials/request"
 	"github.com/aliyun/credentials-go/credentials/response"
-	"github.com/aliyun/credentials-go/credentials/utils"
 )
 
 var debuglog = debug.Init("credential")
diff --git a/credentials/credential_test.go b/credentials/credential_test.go
index d5529a2..a33dbbc 100644
--- a/credentials/credential_test.go
+++ b/credentials/credential_test.go
@@ -5,8 +5,8 @@ import (
 	"testing"
 
 	"github.com/alibabacloud-go/tea/tea"
+	"github.com/aliyun/credentials-go/credentials/internal/utils"
 	"github.com/aliyun/credentials-go/credentials/request"
-	"github.com/aliyun/credentials-go/credentials/utils"
 	"github.com/stretchr/testify/assert"
 )
 
diff --git a/credentials/ecs_ram_role_credentials_provider.go b/credentials/ecs_ram_role_credentials_provider.go
index 70a0520..5a54d7b 100644
--- a/credentials/ecs_ram_role_credentials_provider.go
+++ b/credentials/ecs_ram_role_credentials_provider.go
@@ -7,8 +7,8 @@ import (
 	"time"
 
 	"github.com/alibabacloud-go/tea/tea"
+	"github.com/aliyun/credentials-go/credentials/internal/utils"
 	"github.com/aliyun/credentials-go/credentials/request"
-	"github.com/aliyun/credentials-go/credentials/utils"
 )
 
 var securityCredURL = "http://100.100.100.200/latest/meta-data/ram/security-credentials/"
diff --git a/credentials/internal/utils/runtime.go b/credentials/internal/utils/runtime.go
new file mode 100644
index 0000000..432395c
--- /dev/null
+++ b/credentials/internal/utils/runtime.go
@@ -0,0 +1,36 @@
+package utils
+
+import (
+	"context"
+	"net"
+	"time"
+)
+
+// Runtime is for setting timeout, proxy and host
+type Runtime struct {
+	ReadTimeout    int
+	ConnectTimeout int
+	Proxy          string
+	Host           string
+	STSEndpoint    string
+}
+
+// NewRuntime returns a Runtime
+func NewRuntime(readTimeout, connectTimeout int, proxy string, host string) *Runtime {
+	return &Runtime{
+		ReadTimeout:    readTimeout,
+		ConnectTimeout: connectTimeout,
+		Proxy:          proxy,
+		Host:           host,
+	}
+}
+
+// Timeout is for connect Timeout
+func Timeout(connectTimeout time.Duration) func(cxt context.Context, net, addr string) (c net.Conn, err error) {
+	return func(ctx context.Context, network, address string) (net.Conn, error) {
+		return (&net.Dialer{
+			Timeout:   connectTimeout,
+			DualStack: true,
+		}).DialContext(ctx, network, address)
+	}
+}
diff --git a/credentials/internal/utils/runtime_test.go b/credentials/internal/utils/runtime_test.go
new file mode 100644
index 0000000..873744e
--- /dev/null
+++ b/credentials/internal/utils/runtime_test.go
@@ -0,0 +1,24 @@
+package utils
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_NewRuntime(t *testing.T) {
+	runitme := NewRuntime(10, 10, "proxy", "host")
+	assert.Equal(t, 10, runitme.ReadTimeout)
+	assert.Equal(t, 10, runitme.ConnectTimeout)
+	assert.Equal(t, "proxy", runitme.Proxy)
+	assert.Equal(t, "host", runitme.Host)
+
+	dialContext := Timeout(5 * time.Second)
+	ctx, cancelFunc := context.WithTimeout(context.Background(), 1*time.Second)
+	assert.NotNil(t, cancelFunc)
+	c, err := dialContext(ctx, "127.0.0.1", "127.0.0.2")
+	assert.Nil(t, c)
+	assert.Equal(t, "dial 127.0.0.1: unknown network 127.0.0.1", err.Error())
+}
diff --git a/credentials/oidc_credentials_provider.go b/credentials/oidc_credentials_provider.go
index 8c70343..272a6da 100644
--- a/credentials/oidc_credentials_provider.go
+++ b/credentials/oidc_credentials_provider.go
@@ -10,8 +10,8 @@ import (
 	"time"
 
 	"github.com/alibabacloud-go/tea/tea"
+	"github.com/aliyun/credentials-go/credentials/internal/utils"
 	"github.com/aliyun/credentials-go/credentials/request"
-	"github.com/aliyun/credentials-go/credentials/utils"
 )
 
 // OIDCCredential is a kind of credentials
diff --git a/credentials/oidc_credentials_provider_test.go b/credentials/oidc_credentials_provider_test.go
index b09fe09..7f69818 100644
--- a/credentials/oidc_credentials_provider_test.go
+++ b/credentials/oidc_credentials_provider_test.go
@@ -9,7 +9,7 @@ import (
 
 	"github.com/stretchr/testify/assert"
 
-	"github.com/aliyun/credentials-go/credentials/utils"
+	"github.com/aliyun/credentials-go/credentials/internal/utils"
 )
 
 func TestNewOidcCredentialsProvider(t *testing.T) {
diff --git a/credentials/ram_role_arn_credentials_provider.go b/credentials/ram_role_arn_credentials_provider.go
index a909dd3..71ae004 100644
--- a/credentials/ram_role_arn_credentials_provider.go
+++ b/credentials/ram_role_arn_credentials_provider.go
@@ -8,8 +8,8 @@ import (
 	"time"
 
 	"github.com/alibabacloud-go/tea/tea"
+	"github.com/aliyun/credentials-go/credentials/internal/utils"
 	"github.com/aliyun/credentials-go/credentials/request"
-	"github.com/aliyun/credentials-go/credentials/utils"
 )
 
 const defaultDurationSeconds = 3600
diff --git a/credentials/ram_role_arn_credentials_provider_test.go b/credentials/ram_role_arn_credentials_provider_test.go
index c9f12df..04c66f2 100644
--- a/credentials/ram_role_arn_credentials_provider_test.go
+++ b/credentials/ram_role_arn_credentials_provider_test.go
@@ -8,7 +8,7 @@ import (
 	"strconv"
 	"testing"
 
-	"github.com/aliyun/credentials-go/credentials/utils"
+	"github.com/aliyun/credentials-go/credentials/internal/utils"
 	"github.com/stretchr/testify/assert"
 )
 
diff --git a/credentials/rsa_key_pair_credentials_provider.go b/credentials/rsa_key_pair_credentials_provider.go
index 4b57072..1d86f29 100644
--- a/credentials/rsa_key_pair_credentials_provider.go
+++ b/credentials/rsa_key_pair_credentials_provider.go
@@ -8,8 +8,8 @@ import (
 	"time"
 
 	"github.com/alibabacloud-go/tea/tea"
+	"github.com/aliyun/credentials-go/credentials/internal/utils"
 	"github.com/aliyun/credentials-go/credentials/request"
-	"github.com/aliyun/credentials-go/credentials/utils"
 )
 
 // Deprecated: no more recommend to use it
diff --git a/credentials/rsa_key_pair_credentials_provider_test.go b/credentials/rsa_key_pair_credentials_provider_test.go
index fa28cbc..5687920 100644
--- a/credentials/rsa_key_pair_credentials_provider_test.go
+++ b/credentials/rsa_key_pair_credentials_provider_test.go
@@ -5,7 +5,7 @@ import (
 	"net/http"
 	"testing"
 
-	"github.com/aliyun/credentials-go/credentials/utils"
+	"github.com/aliyun/credentials-go/credentials/internal/utils"
 
 	"github.com/stretchr/testify/assert"
 )
diff --git a/credentials/uri_credential.go b/credentials/uri_credential.go
index 8ac897e..56da596 100644
--- a/credentials/uri_credential.go
+++ b/credentials/uri_credential.go
@@ -7,8 +7,8 @@ import (
 	"time"
 
 	"github.com/alibabacloud-go/tea/tea"
+	"github.com/aliyun/credentials-go/credentials/internal/utils"
 	"github.com/aliyun/credentials-go/credentials/request"
-	"github.com/aliyun/credentials-go/credentials/utils"
 )
 
 // URLCredential is a kind of credential
diff --git a/credentials/utils/runtime.go b/credentials/utils/runtime.go
index 432395c..43830cd 100644
--- a/credentials/utils/runtime.go
+++ b/credentials/utils/runtime.go
@@ -7,6 +7,7 @@ import (
 )
 
 // Runtime is for setting timeout, proxy and host
+// Deprecated: it was used for internal
 type Runtime struct {
 	ReadTimeout    int
 	ConnectTimeout int
@@ -16,6 +17,7 @@ type Runtime struct {
 }
 
 // NewRuntime returns a Runtime
+// Deprecated: it was used for internal
 func NewRuntime(readTimeout, connectTimeout int, proxy string, host string) *Runtime {
 	return &Runtime{
 		ReadTimeout:    readTimeout,
@@ -26,6 +28,7 @@ func NewRuntime(readTimeout, connectTimeout int, proxy string, host string) *Run
 }
 
 // Timeout is for connect Timeout
+// Deprecated: it was used for internal
 func Timeout(connectTimeout time.Duration) func(cxt context.Context, net, addr string) (c net.Conn, err error) {
 	return func(ctx context.Context, network, address string) (net.Conn, error) {
 		return (&net.Dialer{
diff --git a/credentials/utils/utils.go b/credentials/utils/utils.go
index 7468407..66457c3 100644
--- a/credentials/utils/utils.go
+++ b/credentials/utils/utils.go
@@ -30,6 +30,7 @@ var hookRSA = func(fn func(rand io.Reader, priv *rsa.PrivateKey, hash crypto.Has
 }
 
 // GetUUID returns a uuid
+// Deprecated: it was used for internal
 func GetUUID() (uuidHex string) {
 	uuid := newUUID()
 	uuidHex = hex.EncodeToString(uuid[:])
@@ -46,6 +47,7 @@ func RandStringBytes(n int) string {
 }
 
 // ShaHmac1 return a string which has been hashed
+// Deprecated: it was used for internal
 func ShaHmac1(source, secret string) string {
 	key := []byte(secret)
 	hmac := hmac.New(sha1.New, key)
@@ -56,6 +58,7 @@ func ShaHmac1(source, secret string) string {
 }
 
 // Sha256WithRsa return a string which has been hashed with Rsa
+// Deprecated: it was used for internal
 func Sha256WithRsa(source, secret string) string {
 	decodeString, err := base64.StdEncoding.DecodeString(secret)
 	if err != nil {
@@ -79,6 +82,7 @@ func Sha256WithRsa(source, secret string) string {
 }
 
 // GetMD5Base64 returns a string which has been base64
+// Deprecated: it was used for internal
 func GetMD5Base64(bytes []byte) (base64Value string) {
 	md5Ctx := md5.New()
 	md5Ctx.Write(bytes)
@@ -88,6 +92,7 @@ func GetMD5Base64(bytes []byte) (base64Value string) {
 }
 
 // GetTimeInFormatISO8601 returns a time string
+// Deprecated: it was used for internal
 func GetTimeInFormatISO8601() (timeStr string) {
 	gmt := time.FixedZone("GMT", 0)
 
@@ -95,6 +100,7 @@ func GetTimeInFormatISO8601() (timeStr string) {
 }
 
 // GetURLFormedMap returns a url encoded string
+// Deprecated: it was used for internal
 func GetURLFormedMap(source map[string]string) (urlEncoded string) {
 	urlEncoder := url.Values{}
 	for key, value := range source {