diff --git a/tg/keyboard.go b/tg/keyboard.go
index ceb0282..9263edc 100644
--- a/tg/keyboard.go
+++ b/tg/keyboard.go
@@ -26,13 +26,23 @@ func (kbd *Keyboard) Row(btns ...*Button) *Keyboard {
 	if len(btns) < 1 {
 		return kbd
 	}
-	kbd.Rows = append(kbd.Rows, btns)
+	retBtns := []*Button{}
+	for _, btn := range btns {
+		if btn == nil {
+			continue
+		}
+		retBtns = append(retBtns, btn)
+	}
+	kbd.Rows = append(kbd.Rows, retBtns)
 	return kbd
 }
 
 // Adds buttons as one column list.
 func (kbd *Keyboard) List(btns ...*Button) *Keyboard {
 	for _, btn := range btns {
+		if btn == nil {
+			continue
+		}
 		kbd.Rows = append(kbd.Rows, ButtonRow{btn})
 	}
 	return kbd
@@ -78,6 +88,8 @@ func (kbd *Keyboard) Inline() *Inline {
 func (kbd *Keyboard) Reply() *Reply {
 	ret := &Reply{}
 	ret.Keyboard = kbd
+	// it is used more often than not once.
+	ret.OneTime = true
 	return ret
 }
 
diff --git a/tg/message.go b/tg/message.go
index 5bda431..754bb37 100644
--- a/tg/message.go
+++ b/tg/message.go
@@ -7,7 +7,7 @@ import (
 )
 type Message = tgbotapi.Message
 
-// Simple text message type.
+// Simple text message component type.
 type MessageCompo struct {
 	Message *Message
 	ParseMode string
@@ -16,6 +16,7 @@ type MessageCompo struct {
 
 var (
 	escapeRe = re.MustCompile(`([_*\[\]()~`+"`"+`>#+-=|{}.!])`)
+	NewRawMessage = tgbotapi.NewMessage
 )
 
 // Escape special characters in Markdown 2 and return the
@@ -24,6 +25,8 @@ func Escape2(str string) string {
 	return string(escapeRe.ReplaceAll([]byte(str), []byte("\\$1")))
 }
 
+// Is only implemented to make it sendable and so we can put it
+// return of rendering functions.
 func (compo *MessageCompo) SetMessage(msg *Message) {
 	compo.Message = msg
 }
@@ -36,6 +39,7 @@ func NewMessage(text string) *MessageCompo {
 	return ret
 }
 
+// Return message with the specified parse mode.
 func (msg *MessageCompo) withParseMode(mode string) *MessageCompo {
 	msg.ParseMode = mode
 	return msg
@@ -97,9 +101,9 @@ func (config *MessageCompo) SendConfig(
 }
 
 // Empty serving to use messages in rendering.
-func (compo *MessageCompo) Serve(c *Context) {
-}
+func (compo *MessageCompo) Serve(c *Context) {}
 
+// Filter that skips everything. Messages cannot do anything with updates.
 func (compo *MessageCompo) Filter(_ *Update) bool {
 	// Skip everything
 	return true
diff --git a/tg/session.go b/tg/session.go
index 2ffa67d..6f31ce4 100644
--- a/tg/session.go
+++ b/tg/session.go
@@ -10,9 +10,11 @@ const (
 	ChannelSessionScope
 )
 
+type ChatId int64
+
 // Represents unique value to identify chats.
 // In fact is simply ID of the chat.
-type SessionId int64
+type SessionId = ChatId
 
 // Convert the SessionId to Telegram API's type.
 func (si SessionId) ToApi() int64 {