diff --git a/README.md b/README.md
index f1cc93c..ddbf72b 100644
--- a/README.md
+++ b/README.md
@@ -9,9 +9,11 @@ There's some library in Go support you to create your Minecraft client or server
 这是一些Golang库，用于帮助你编写自己的Minecraft客户端或服务器，
 - [x] Mojang authenticate
 - [x] Minecraft network protocal
-- [x] Parse chat message
+- [x] Chat
 - [x] Simple MC robot lib
 - [x] Parse NBT
+- [x] Use item
+- [x] Swing arm
 
 > 由于仍在开发中，部分API在未来版本中可能会变动
 
diff --git a/bot/mcbot.go b/bot/mcbot.go
index a06f9db..784e4f3 100644
--- a/bot/mcbot.go
+++ b/bot/mcbot.go
@@ -148,7 +148,9 @@ func (c *Client) JoinServer(addr string, port int) (err error) {
 			}
 			c.conn.SetThreshold(int(threshold))
 		case 0x04: //Login Plugin Request
-			// fmt.Println("Waring Login Plugin Request")//TODO: handle plugin request
+			if err := handlePluginPacket(c, pack); err != nil {
+				return fmt.Errorf("bot: handle plugin packet fail: %v", err)
+			}
 		}
 	}
 }
diff --git a/bot/motion.go b/bot/motion.go
index b7bf8c0..e8d8850 100644
--- a/bot/motion.go
+++ b/bot/motion.go
@@ -1,13 +1,14 @@
 package bot
 
 import (
-	"fmt"
+	"errors"
 	"github.com/Tnze/go-mc/data"
 	pk "github.com/Tnze/go-mc/net/packet"
 )
 
 //SwingArm swing player's arm.
-//hand could be one of 0: main hand, 1: off hand
+//hand could be one of 0: main hand, 1: off hand.
+//It's just animation.
 func (c *Client) SwingArm(hand int) error {
 	return c.conn.WritePacket(pk.Marshal(
 		data.AnimationServerbound,
@@ -35,7 +36,7 @@ func (c *Client) UseItem(hand int) error {
 //Chat send chat as chat message or command at textbox.
 func (c *Client) Chat(msg string) error {
 	if len(msg) > 256 {
-		return fmt.Errorf("message too long")
+		return errors.New("message too long")
 	}
 
 	return c.conn.WritePacket(pk.Marshal(