diff --git a/dtmcli/barrier.go b/dtmcli/barrier.go
index 5daf8fa..eaef70c 100644
--- a/dtmcli/barrier.go
+++ b/dtmcli/barrier.go
@@ -9,8 +9,10 @@ import (
 	"github.com/yedf/dtm/common"
 )
 
+// BusiFunc type for busi func
 type BusiFunc func(db *sql.DB) (interface{}, error)
 
+// TransInfo every branch info
 type TransInfo struct {
 	TransType  string
 	Gid        string
@@ -22,6 +24,7 @@ func (t *TransInfo) String() string {
 	return fmt.Sprintf("transInfo: %s %s %s %s", t.TransType, t.Gid, t.BranchID, t.BranchType)
 }
 
+// TransInfoFromReq construct transaction info from request
 func TransInfoFromReq(c *gin.Context) *TransInfo {
 	ti := &TransInfo{
 		TransType:  c.Query("trans_type"),
@@ -35,11 +38,13 @@ func TransInfoFromReq(c *gin.Context) *TransInfo {
 	return ti
 }
 
+// BarrierModel barrier model for gorm
 type BarrierModel struct {
 	common.ModelBase
 	TransInfo
 }
 
+// TableName gorm table name
 func (BarrierModel) TableName() string { return "dtm_barrier.barrier" }
 
 func insertBarrier(tx *sql.Tx, transType string, gid string, branchID string, branchType string) (int64, error) {
@@ -53,6 +58,7 @@ func insertBarrier(tx *sql.Tx, transType string, gid string, branchID string, br
 	return res.RowsAffected()
 }
 
+// ThroughBarrierCall barrier interface. busiCall will be called only when the request is necessary
 func ThroughBarrierCall(db *sql.DB, transInfo *TransInfo, busiCall BusiFunc) (res interface{}, rerr error) {
 	tx, rerr := db.BeginTx(context.Background(), &sql.TxOptions{})
 	if rerr != nil {
diff --git a/dtmcli/message.go b/dtmcli/message.go
index a5f984b..933bbe3 100644
--- a/dtmcli/message.go
+++ b/dtmcli/message.go
@@ -8,22 +8,27 @@ import (
 	"github.com/yedf/dtm/common"
 )
 
+// Msg reliable msg type
 type Msg struct {
 	MsgData
 	Server string
 }
 
+// MsgData msg data
 type MsgData struct {
 	Gid           string    `json:"gid"`
 	TransType     string    `json:"trans_type"`
 	Steps         []MsgStep `json:"steps"`
 	QueryPrepared string    `json:"query_prepared"`
 }
+
+// MsgStep struct of one step msg
 type MsgStep struct {
 	Action string `json:"action"`
 	Data   string `json:"data"`
 }
 
+// NewMsg create new msg
 func NewMsg(server string) *Msg {
 	return &Msg{
 		MsgData: MsgData{
@@ -33,6 +38,8 @@ func NewMsg(server string) *Msg {
 		Server: server,
 	}
 }
+
+// Add add a new step
 func (s *Msg) Add(action string, postData interface{}) *Msg {
 	logrus.Printf("msg %s Add %s %v", s.Gid, action, postData)
 	step := MsgStep{
@@ -43,6 +50,7 @@ func (s *Msg) Add(action string, postData interface{}) *Msg {
 	return s
 }
 
+// Submit submit the msg
 func (s *Msg) Submit() error {
 	logrus.Printf("committing %s body: %v", s.Gid, &s.MsgData)
 	resp, err := common.RestyClient.R().SetBody(&s.MsgData).Post(fmt.Sprintf("%s/submit", s.Server))
@@ -56,6 +64,7 @@ func (s *Msg) Submit() error {
 	return nil
 }
 
+// Prepare prepare the msg
 func (s *Msg) Prepare(queryPrepared string) error {
 	s.QueryPrepared = common.OrString(queryPrepared, s.QueryPrepared)
 	logrus.Printf("preparing %s body: %v", s.Gid, &s.MsgData)
diff --git a/dtmcli/saga.go b/dtmcli/saga.go
index bf615c7..7399570 100644
--- a/dtmcli/saga.go
+++ b/dtmcli/saga.go
@@ -8,22 +8,27 @@ import (
 	"github.com/yedf/dtm/common"
 )
 
+// Saga struct of saga
 type Saga struct {
 	SagaData
 	Server string
 }
 
+// SagaData sage data
 type SagaData struct {
 	Gid       string     `json:"gid"`
 	TransType string     `json:"trans_type"`
 	Steps     []SagaStep `json:"steps"`
 }
+
+// SagaStep one step of saga
 type SagaStep struct {
 	Action     string `json:"action"`
 	Compensate string `json:"compensate"`
 	Data       string `json:"data"`
 }
 
+// NewSaga create a saga
 func NewSaga(server string) *Saga {
 	return &Saga{
 		SagaData: SagaData{
@@ -32,6 +37,8 @@ func NewSaga(server string) *Saga {
 		Server: server,
 	}
 }
+
+// Add add a saga step
 func (s *Saga) Add(action string, compensate string, postData interface{}) *Saga {
 	logrus.Printf("saga %s Add %s %s %v", s.Gid, action, compensate, postData)
 	step := SagaStep{
@@ -43,6 +50,7 @@ func (s *Saga) Add(action string, compensate string, postData interface{}) *Saga
 	return s
 }
 
+// Submit submit the saga trans
 func (s *Saga) Submit() error {
 	logrus.Printf("committing %s body: %v", s.Gid, &s.SagaData)
 	resp, err := common.RestyClient.R().SetBody(&s.SagaData).Post(fmt.Sprintf("%s/submit", s.Server))
diff --git a/dtmcli/tcc.go b/dtmcli/tcc.go
index 50483e1..04386ec 100644
--- a/dtmcli/tcc.go
+++ b/dtmcli/tcc.go
@@ -8,14 +8,17 @@ import (
 	"github.com/yedf/dtm/common"
 )
 
+// Tcc struct of tcc
 type Tcc struct {
 	IDGenerator
 	Dtm string
 	Gid string
 }
 
+// TccGlobalFunc type of global tcc call
 type TccGlobalFunc func(tcc *Tcc) error
 
+// TccGlobalTransaction begin a tcc global transaction
 func TccGlobalTransaction(dtm string, tccFunc TccGlobalFunc) (gid string, rerr error) {
 	gid = GenGid(dtm)
 	data := &M{
@@ -38,6 +41,7 @@ func TccGlobalTransaction(dtm string, tccFunc TccGlobalFunc) (gid string, rerr e
 	return
 }
 
+// TccFromReq tcc from request info
 func TccFromReq(c *gin.Context) (*Tcc, error) {
 	tcc := &Tcc{
 		Dtm:         c.Query("dtm"),
@@ -50,7 +54,8 @@ func TccFromReq(c *gin.Context) (*Tcc, error) {
 	return tcc, nil
 }
 
-func (t *Tcc) CallBranch(body interface{}, tryUrl string, confirmUrl string, cancelUrl string) (*resty.Response, error) {
+// CallBranch call a tcc branch
+func (t *Tcc) CallBranch(body interface{}, tryURL string, confirmURL string, cancelURL string) (*resty.Response, error) {
 	branchID := t.NewBranchID()
 	resp, err := common.RestyClient.R().
 		SetBody(&M{
@@ -59,9 +64,9 @@ func (t *Tcc) CallBranch(body interface{}, tryUrl string, confirmUrl string, can
 			"trans_type": "tcc",
 			"status":     "prepared",
 			"data":       string(common.MustMarshal(body)),
-			"try":        tryUrl,
-			"confirm":    confirmUrl,
-			"cancel":     cancelUrl,
+			"try":        tryURL,
+			"confirm":    confirmURL,
+			"cancel":     cancelURL,
 		}).
 		Post(t.Dtm + "/registerTccBranch")
 	if err != nil {
@@ -75,5 +80,5 @@ func (t *Tcc) CallBranch(body interface{}, tryUrl string, confirmUrl string, can
 			"trans_type":  "tcc",
 			"branch_type": "try",
 		}).
-		Post(tryUrl)
+		Post(tryURL)
 }
diff --git a/dtmcli/types.go b/dtmcli/types.go
index 7b88b45..d6766f9 100644
--- a/dtmcli/types.go
+++ b/dtmcli/types.go
@@ -6,6 +6,7 @@ import (
 	"github.com/yedf/dtm/common"
 )
 
+// GenGid generate a new gid
 func GenGid(server string) string {
 	res := common.MS{}
 	_, err := common.RestyClient.R().SetResult(&res).Get(server + "/newGid")
@@ -13,11 +14,13 @@ func GenGid(server string) string {
 	return res["gid"]
 }
 
+// IDGenerator used to generate a branch id
 type IDGenerator struct {
 	parentID string
 	branchID int
 }
 
+// NewBranchID generate a branch id
 func (g *IDGenerator) NewBranchID() string {
 	if g.branchID >= 99 {
 		panic(fmt.Errorf("branch id is larger than 99"))
diff --git a/dtmcli/xa.go b/dtmcli/xa.go
index 54f84ff..537c078 100644
--- a/dtmcli/xa.go
+++ b/dtmcli/xa.go
@@ -10,25 +10,31 @@ import (
 	"github.com/yedf/dtm/common"
 )
 
+// M alias
 type M = map[string]interface{}
 
 var e2p = common.E2P
 
+// XaGlobalFunc type of xa global function
 type XaGlobalFunc func(xa *Xa) error
 
+// XaLocalFunc type of xa local function
 type XaLocalFunc func(db *common.DB, xa *Xa) error
 
+// XaClient xa client
 type XaClient struct {
 	Server      string
 	Conf        map[string]string
-	CallbackUrl string
+	CallbackURL string
 }
 
+// Xa xa transaction
 type Xa struct {
 	IDGenerator
 	Gid string
 }
 
+// GetParams get xa params map
 func (x *Xa) GetParams(branchID string) common.MS {
 	return common.MS{
 		"gid":         x.Gid,
@@ -38,6 +44,7 @@ func (x *Xa) GetParams(branchID string) common.MS {
 	}
 }
 
+// XaFromReq construct xa info from request
 func XaFromReq(c *gin.Context) *Xa {
 	return &Xa{
 		Gid:         c.Query("gid"),
@@ -45,17 +52,19 @@ func XaFromReq(c *gin.Context) *Xa {
 	}
 }
 
+// NewXaBranchID generate a xa branch id
 func (x *Xa) NewXaBranchID() string {
 	return x.Gid + "-" + x.NewBranchID()
 }
 
-func NewXaClient(server string, mysqlConf map[string]string, app *gin.Engine, callbackUrl string) *XaClient {
+// NewXaClient construct a xa client
+func NewXaClient(server string, mysqlConf map[string]string, app *gin.Engine, callbackURL string) *XaClient {
 	xa := &XaClient{
 		Server:      server,
 		Conf:        mysqlConf,
-		CallbackUrl: callbackUrl,
+		CallbackURL: callbackURL,
 	}
-	u, err := url.Parse(callbackUrl)
+	u, err := url.Parse(callbackURL)
 	e2p(err)
 	app.POST(u.Path, common.WrapHandler(func(c *gin.Context) (interface{}, error) {
 		type CallbackReq struct {
@@ -82,18 +91,19 @@ func NewXaClient(server string, mysqlConf map[string]string, app *gin.Engine, ca
 	return xa
 }
 
+// XaLocalTransaction start a xa local transaction
 func (xc *XaClient) XaLocalTransaction(c *gin.Context, transFunc XaLocalFunc) (rerr error) {
 	defer common.P2E(&rerr)
 	xa := XaFromReq(c)
-	branchId := xa.NewBranchID()
-	xaBranch := xa.Gid + "-" + branchId
+	branchID := xa.NewBranchID()
+	xaBranch := xa.Gid + "-" + branchID
 	tx, my := common.DbAlone(xc.Conf)
 	defer func() { my.Close() }()
 	tx.Must().Exec(fmt.Sprintf("XA start '%s'", xaBranch))
 	err := transFunc(tx, xa)
 	e2p(err)
 	resp, err := common.RestyClient.R().
-		SetBody(&M{"gid": xa.Gid, "branch_id": branchId, "trans_type": "xa", "status": "prepared", "url": xc.CallbackUrl}).
+		SetBody(&M{"gid": xa.Gid, "branch_id": branchID, "trans_type": "xa", "status": "prepared", "url": xc.CallbackURL}).
 		Post(xc.Server + "/registerXaBranch")
 	e2p(err)
 	if !strings.Contains(resp.String(), "SUCCESS") {
@@ -104,6 +114,7 @@ func (xc *XaClient) XaLocalTransaction(c *gin.Context, transFunc XaLocalFunc) (r
 	return nil
 }
 
+// XaGlobalTransaction start a xa global transaction
 func (xc *XaClient) XaGlobalTransaction(transFunc XaGlobalFunc) (gid string, rerr error) {
 	xa := Xa{IDGenerator: IDGenerator{}, Gid: GenGid(xc.Server)}
 	gid = xa.Gid
@@ -133,12 +144,13 @@ func (xc *XaClient) XaGlobalTransaction(transFunc XaGlobalFunc) (gid string, rer
 	return
 }
 
-func (xa *Xa) CallBranch(body interface{}, url string) (*resty.Response, error) {
-	branchID := xa.NewBranchID()
+// CallBranch call a xa branch
+func (x *Xa) CallBranch(body interface{}, url string) (*resty.Response, error) {
+	branchID := x.NewBranchID()
 	return common.RestyClient.R().
 		SetBody(body).
 		SetQueryParams(common.MS{
-			"gid":         xa.Gid,
+			"gid":         x.Gid,
 			"branch_id":   branchID,
 			"trans_type":  "xa",
 			"branch_type": "action",