diff --git a/client/builders.go b/client/builders.go
index ebb530e7..e69e66c9 100644
--- a/client/builders.go
+++ b/client/builders.go
@@ -10,6 +10,7 @@ import (
 	"github.com/Mrs4s/MiraiGo/binary/jce"
 	"github.com/Mrs4s/MiraiGo/client/internal/auth"
 	"github.com/Mrs4s/MiraiGo/client/internal/codec"
+	"github.com/Mrs4s/MiraiGo/client/internal/network"
 	"github.com/Mrs4s/MiraiGo/client/pb"
 	"github.com/Mrs4s/MiraiGo/client/pb/cmd0x352"
 	"github.com/Mrs4s/MiraiGo/client/pb/msg"
@@ -90,9 +91,16 @@ func (c *QQClient) buildLoginPacket() (uint16, []byte) {
 		w.Write(tlv.T521(0))
 		w.Write(tlv.T525(tlv.T536([]byte{0x01, 0x00})))
 	}))
-	sso := packets.BuildSsoPacket(seq, c.version.AppId, c.version.SubAppId, "wtlogin.login", c.deviceInfo.IMEI, EmptyBytes, c.OutGoingPacketSessionId, req, c.ksid)
-	packet := packets.BuildLoginPacket(c.Uin, 2, make([]byte, 16), sso, EmptyBytes)
-	return seq, packet
+
+	req2 := network.Request{
+		Type:        network.RequestTypeLogin,
+		EncryptType: network.EncryptTypeEmptyKey,
+		SequenceID:  int32(seq),
+		Uin:         c.Uin,
+		CommandName: "wtlogin.login",
+		Body:        req,
+	}
+	return seq, c.transport.PackPacket(&req2)
 }
 
 func (c *QQClient) buildDeviceLockLoginPacket() (uint16, []byte) {
@@ -102,13 +110,19 @@ func (c *QQClient) buildDeviceLockLoginPacket() (uint16, []byte) {
 		w.WriteUInt16(4)
 
 		w.Write(tlv.T8(2052))
-		w.Write(tlv.T104(c.t104))
+		w.Write(tlv.T104(c.sig.T104))
 		w.Write(tlv.T116(c.version.MiscBitmap, c.version.SubSigmap))
-		w.Write(tlv.T401(c.g))
+		w.Write(tlv.T401(c.sig.G))
 	}))
-	sso := packets.BuildSsoPacket(seq, c.version.AppId, c.version.SubAppId, "wtlogin.login", c.deviceInfo.IMEI, EmptyBytes, c.OutGoingPacketSessionId, req, c.ksid)
-	packet := packets.BuildLoginPacket(c.Uin, 2, make([]byte, 16), sso, EmptyBytes)
-	return seq, packet
+	req2 := network.Request{
+		Type:        network.RequestTypeLogin,
+		EncryptType: network.EncryptTypeEmptyKey,
+		SequenceID:  int32(seq),
+		Uin:         c.Uin,
+		CommandName: "wtlogin.login",
+		Body:        req,
+	}
+	return seq, c.transport.PackPacket(&req2)
 }
 
 func (c *QQClient) buildQRCodeFetchRequestPacket() (uint16, []byte) {
@@ -133,13 +147,21 @@ func (c *QQClient) buildQRCodeFetchRequestPacket() (uint16, []byte) {
 			w.Write(tlv.T35(8))
 		}))
 	}))
-	sso := packets.BuildSsoPacket(seq, watch.AppId, c.version.SubAppId, "wtlogin.trans_emp", c.deviceInfo.IMEI, EmptyBytes, c.OutGoingPacketSessionId, req, c.ksid)
-	packet := packets.BuildLoginPacket(0, 2, make([]byte, 16), sso, EmptyBytes)
-	return seq, packet
+
+	req2 := network.Request{
+		Type:        network.RequestTypeLogin,
+		EncryptType: network.EncryptTypeEmptyKey,
+		SequenceID:  int32(seq),
+		Uin:         0,
+		CommandName: "wtlogin.trans_emp",
+		Body:        req,
+	}
+	return seq, c.transport.PackPacket(&req2)
 }
 
 func (c *QQClient) buildQRCodeResultQueryRequestPacket(sig []byte) (uint16, []byte) {
-	watch := auth.AndroidWatch.Version()
+	version := c.transport.Version
+	c.transport.Version = auth.AndroidWatch.Version()
 	seq := c.nextSeq()
 	req := c.buildOicqRequestPacket(0, 0x0812, binary.NewWriterF(func(w *binary.Writer) {
 		w.WriteHex(`0000620000001000000072000000`) // trans header
@@ -156,9 +178,18 @@ func (c *QQClient) buildQRCodeResultQueryRequestPacket(sig []byte) (uint16, []by
 			w.WriteUInt16(0) // const
 		}))
 	}))
-	sso := packets.BuildSsoPacket(seq, watch.AppId, c.version.SubAppId, "wtlogin.trans_emp", c.deviceInfo.IMEI, EmptyBytes, c.OutGoingPacketSessionId, req, c.ksid)
-	packet := packets.BuildLoginPacket(0, 2, make([]byte, 16), sso, EmptyBytes)
-	return seq, packet
+
+	req2 := network.Request{
+		Type:        network.RequestTypeLogin,
+		EncryptType: network.EncryptTypeEmptyKey,
+		SequenceID:  int32(seq),
+		Uin:         0,
+		CommandName: "wtlogin.trans_emp",
+		Body:        req,
+	}
+	payload := c.transport.PackPacket(&req2)
+	c.transport.Version = version
+	return seq, payload
 }
 
 func (c *QQClient) buildQRCodeLoginPacket(t106, t16a, t318 []byte) (uint16, []byte) {
@@ -230,9 +261,16 @@ func (c *QQClient) buildQRCodeLoginPacket(t106, t16a, t318 []byte) (uint16, []by
 		w.Write(wb)
 		cl()
 	}))
-	sso := packets.BuildSsoPacket(seq, c.version.AppId, c.version.SubAppId, "wtlogin.login", c.deviceInfo.IMEI, EmptyBytes, c.OutGoingPacketSessionId, req, c.ksid)
-	packet := packets.BuildLoginPacket(c.Uin, 2, make([]byte, 16), sso, EmptyBytes)
-	return seq, packet
+
+	req2 := network.Request{
+		Type:        network.RequestTypeLogin,
+		EncryptType: network.EncryptTypeEmptyKey,
+		SequenceID:  int32(seq),
+		Uin:         c.Uin,
+		CommandName: "wtlogin.login",
+		Body:        req,
+	}
+	return seq, c.transport.PackPacket(&req2)
 }
 
 func (c *QQClient) buildCaptchaPacket(result string, sign []byte) (uint16, []byte) {
@@ -243,12 +281,19 @@ func (c *QQClient) buildCaptchaPacket(result string, sign []byte) (uint16, []byt
 
 		w.Write(tlv.T2(result, sign))
 		w.Write(tlv.T8(2052))
-		w.Write(tlv.T104(c.t104))
+		w.Write(tlv.T104(c.sig.T104))
 		w.Write(tlv.T116(c.version.MiscBitmap, c.version.SubSigmap))
 	}))
-	sso := packets.BuildSsoPacket(seq, c.version.AppId, c.version.SubAppId, "wtlogin.login", c.deviceInfo.IMEI, EmptyBytes, c.OutGoingPacketSessionId, req, c.ksid)
-	packet := packets.BuildLoginPacket(c.Uin, 2, make([]byte, 16), sso, EmptyBytes)
-	return seq, packet
+
+	req2 := network.Request{
+		Type:        network.RequestTypeLogin,
+		EncryptType: network.EncryptTypeEmptyKey,
+		SequenceID:  int32(seq),
+		Uin:         c.Uin,
+		CommandName: "wtlogin.login",
+		Body:        req,
+	}
+	return seq, c.transport.PackPacket(&req2)
 }
 
 func (c *QQClient) buildSMSRequestPacket() (uint16, []byte) {
@@ -258,15 +303,22 @@ func (c *QQClient) buildSMSRequestPacket() (uint16, []byte) {
 		w.WriteUInt16(6)
 
 		w.Write(tlv.T8(2052))
-		w.Write(tlv.T104(c.t104))
+		w.Write(tlv.T104(c.sig.T104))
 		w.Write(tlv.T116(c.version.MiscBitmap, c.version.SubSigmap))
-		w.Write(tlv.T174(c.t174))
+		w.Write(tlv.T174(c.sig.T174))
 		w.Write(tlv.T17A(9))
 		w.Write(tlv.T197())
 	}))
-	sso := packets.BuildSsoPacket(seq, c.version.AppId, c.version.SubAppId, "wtlogin.login", c.deviceInfo.IMEI, EmptyBytes, c.OutGoingPacketSessionId, req, c.ksid)
-	packet := packets.BuildLoginPacket(c.Uin, 2, make([]byte, 16), sso, EmptyBytes)
-	return seq, packet
+
+	req2 := network.Request{
+		Type:        network.RequestTypeLogin,
+		EncryptType: network.EncryptTypeEmptyKey,
+		SequenceID:  int32(seq),
+		Uin:         c.Uin,
+		CommandName: "wtlogin.login",
+		Body:        req,
+	}
+	return seq, c.transport.PackPacket(&req2)
 }
 
 func (c *QQClient) buildSMSCodeSubmitPacket(code string) (uint16, []byte) {
@@ -276,16 +328,23 @@ func (c *QQClient) buildSMSCodeSubmitPacket(code string) (uint16, []byte) {
 		w.WriteUInt16(7)
 
 		w.Write(tlv.T8(2052))
-		w.Write(tlv.T104(c.t104))
+		w.Write(tlv.T104(c.sig.T104))
 		w.Write(tlv.T116(c.version.MiscBitmap, c.version.SubSigmap))
-		w.Write(tlv.T174(c.t174))
+		w.Write(tlv.T174(c.sig.T174))
 		w.Write(tlv.T17C(code))
-		w.Write(tlv.T401(c.g))
+		w.Write(tlv.T401(c.sig.G))
 		w.Write(tlv.T198())
 	}))
-	sso := packets.BuildSsoPacket(seq, c.version.AppId, c.version.SubAppId, "wtlogin.login", c.deviceInfo.IMEI, EmptyBytes, c.OutGoingPacketSessionId, req, c.ksid)
-	packet := packets.BuildLoginPacket(c.Uin, 2, make([]byte, 16), sso, EmptyBytes)
-	return seq, packet
+
+	req2 := network.Request{
+		Type:        network.RequestTypeLogin,
+		EncryptType: network.EncryptTypeEmptyKey,
+		SequenceID:  int32(seq),
+		Uin:         c.Uin,
+		CommandName: "wtlogin.login",
+		Body:        req,
+	}
+	return seq, c.transport.PackPacket(&req2)
 }
 
 func (c *QQClient) buildTicketSubmitPacket(ticket string) (uint16, []byte) {
@@ -296,12 +355,19 @@ func (c *QQClient) buildTicketSubmitPacket(ticket string) (uint16, []byte) {
 
 		w.Write(tlv.T193(ticket))
 		w.Write(tlv.T8(2052))
-		w.Write(tlv.T104(c.t104))
+		w.Write(tlv.T104(c.sig.T104))
 		w.Write(tlv.T116(c.version.MiscBitmap, c.version.SubSigmap))
 	}))
-	sso := packets.BuildSsoPacket(seq, c.version.AppId, c.version.SubAppId, "wtlogin.login", c.deviceInfo.IMEI, EmptyBytes, c.OutGoingPacketSessionId, req, c.ksid)
-	packet := packets.BuildLoginPacket(c.Uin, 2, make([]byte, 16), sso, EmptyBytes)
-	return seq, packet
+
+	req2 := network.Request{
+		Type:        network.RequestTypeLogin,
+		EncryptType: network.EncryptTypeEmptyKey,
+		SequenceID:  int32(seq),
+		Uin:         c.Uin,
+		CommandName: "wtlogin.login",
+		Body:        req,
+	}
+	return seq, c.transport.PackPacket(&req2)
 }
 
 func (c *QQClient) buildRequestTgtgtNopicsigPacket() (uint16, []byte) {
@@ -314,14 +380,14 @@ func (c *QQClient) buildRequestTgtgtNopicsigPacket() (uint16, []byte) {
 		w.Write(tlv.T1(uint32(c.Uin), c.deviceInfo.IpAddress))
 		wb, cl := binary.OpenWriterF(func(bw *binary.Writer) {
 			bw.WriteUInt16(0x106)
-			bw.WriteBytesShort(c.sigInfo.EncryptedA1)
+			bw.WriteBytesShort(c.sig.EncryptedA1)
 		})
 		w.Write(wb)
 		cl()
 		w.Write(tlv.T116(c.version.MiscBitmap, c.version.SubSigmap))
 		w.Write(tlv.T100(c.version.SSOVersion, 2, c.version.MainSigMap))
 		w.Write(tlv.T107(0))
-		w.Write(tlv.T108(c.ksid))
+		w.Write(tlv.T108(c.sig.Ksid))
 		w.Write(tlv.T144(
 			c.deviceInfo.AndroidId,
 			c.deviceInfo.GenDeviceInfoData(),
@@ -337,7 +403,7 @@ func (c *QQClient) buildRequestTgtgtNopicsigPacket() (uint16, []byte) {
 		))
 		w.Write(tlv.T142(c.version.ApkId))
 		w.Write(tlv.T145(c.deviceInfo.Guid))
-		w.Write(tlv.T16A(c.sigInfo.SrmToken))
+		w.Write(tlv.T16A(c.sig.SrmToken))
 		w.Write(tlv.T154(seq))
 		w.Write(tlv.T141(c.deviceInfo.SimInfo, c.deviceInfo.APN))
 		w.Write(tlv.T8(2052))
@@ -348,7 +414,7 @@ func (c *QQClient) buildRequestTgtgtNopicsigPacket() (uint16, []byte) {
 		}))
 		w.Write(tlv.T147(16, []byte(c.version.SortVersionName), c.version.ApkSign))
 		w.Write(tlv.T177(c.version.BuildTime, c.version.SdkVersion))
-		w.Write(tlv.T400(c.g, c.Uin, c.deviceInfo.Guid, c.dpwd, 1, 16, c.randSeed))
+		w.Write(tlv.T400(c.sig.G, c.Uin, c.deviceInfo.Guid, c.sig.Dpwd, 1, 16, c.sig.RandSeed))
 		w.Write(tlv.T187(c.deviceInfo.MacAddress))
 		w.Write(tlv.T188(c.deviceInfo.AndroidId))
 		w.Write(tlv.T194(c.deviceInfo.IMSIMd5))
@@ -363,23 +429,20 @@ func (c *QQClient) buildRequestTgtgtNopicsigPacket() (uint16, []byte) {
 	oicq := codec.OICQ{
 		Uin:           uint32(c.Uin),
 		Command:       0x810,
-		EncryptMethod: crypto.NewEncryptSession(c.sigInfo.T133),
-		Key:           c.sigInfo.WtSessionTicketKey,
+		EncryptMethod: crypto.NewEncryptSession(c.sig.T133),
+		Key:           c.sig.WtSessionTicketKey,
 		Body:          req,
 	}
 
-	uni := codec.Uni{
+	nreq := network.Request{
+		Type:        network.RequestTypeSimple,
+		EncryptType: network.EncryptTypeEmptyKey,
 		Uin:         c.Uin,
-		Seq:         seq,
+		SequenceID:  int32(seq),
 		CommandName: "wtlogin.exchange_emp",
-		EncryptType: 2,
-		SessionID:   c.OutGoingPacketSessionId,
-		ExtraData:   EmptyBytes,
-		Key:         make([]byte, 16),
 		Body:        oicq.Encode(),
 	}
-
-	return seq, uni.Encode()
+	return seq, c.transport.PackPacket(&nreq)
 }
 
 func (c *QQClient) buildRequestChangeSigPacket(mainSigMap uint32) (uint16, []byte) {
@@ -389,10 +452,10 @@ func (c *QQClient) buildRequestChangeSigPacket(mainSigMap uint32) (uint16, []byt
 		w.WriteUInt16(17)
 
 		w.Write(tlv.T100(c.version.SSOVersion, 100, mainSigMap))
-		w.Write(tlv.T10A(c.sigInfo.TGT))
+		w.Write(tlv.T10A(c.sig.TGT))
 		w.Write(tlv.T116(c.version.MiscBitmap, c.version.SubSigmap))
-		w.Write(tlv.T108(c.ksid))
-		h := md5.Sum(c.sigInfo.D2Key)
+		w.Write(tlv.T108(c.sig.Ksid))
+		h := md5.Sum(c.sig.D2Key)
 		w.Write(tlv.T144(
 			c.deviceInfo.AndroidId,
 			c.deviceInfo.GenDeviceInfoData(),
@@ -406,7 +469,7 @@ func (c *QQClient) buildRequestChangeSigPacket(mainSigMap uint32) (uint16, []byt
 			c.deviceInfo.Brand,
 			h[:],
 		))
-		w.Write(tlv.T143(c.sigInfo.D2))
+		w.Write(tlv.T143(c.sig.D2))
 		w.Write(tlv.T142(c.version.ApkId))
 		w.Write(tlv.T154(seq))
 		w.Write(tlv.T18(16, uint32(c.Uin)))
@@ -424,9 +487,16 @@ func (c *QQClient) buildRequestChangeSigPacket(mainSigMap uint32) (uint16, []byt
 		}))
 		// w.Write(tlv.T202(c.deviceInfo.WifiBSSID, c.deviceInfo.WifiSSID))
 	}))
-	sso := packets.BuildSsoPacket(seq, c.version.AppId, c.version.SubAppId, "wtlogin.exchange_emp", c.deviceInfo.IMEI, c.sigInfo.TGT, c.OutGoingPacketSessionId, req, c.ksid)
-	packet := packets.BuildLoginPacket(c.Uin, 2, make([]byte, 16), sso, EmptyBytes)
-	return seq, packet
+
+	req2 := network.Request{
+		Type:        network.RequestTypeLogin,
+		EncryptType: network.EncryptTypeEmptyKey,
+		SequenceID:  int32(seq),
+		Uin:         c.Uin,
+		CommandName: "wtlogin.exchange_emp",
+		Body:        req,
+	}
+	return seq, c.transport.PackPacket(&req2)
 }
 
 // StatSvc.register
@@ -472,9 +542,16 @@ func (c *QQClient) buildClientRegisterPacket() (uint16, []byte) {
 		Context:      make(map[string]string),
 		Status:       make(map[string]string),
 	}
-	sso := packets.BuildSsoPacket(seq, c.version.AppId, c.version.SubAppId, "StatSvc.register", c.deviceInfo.IMEI, c.sigInfo.TGT, c.OutGoingPacketSessionId, pkt.ToBytes(), c.ksid)
-	packet := packets.BuildLoginPacket(c.Uin, 1, c.sigInfo.D2Key, sso, c.sigInfo.D2)
-	return seq, packet
+
+	req2 := network.Request{
+		Type:        network.RequestTypeLogin,
+		EncryptType: network.EncryptTypeD2Key,
+		SequenceID:  int32(seq),
+		Uin:         c.Uin,
+		CommandName: "StatSvc.register",
+		Body:        pkt.ToBytes(),
+	}
+	return seq, c.transport.PackPacket(&req2)
 }
 
 func (c *QQClient) buildStatusSetPacket(status, extStatus int32) (uint16, []byte) {
@@ -766,7 +843,7 @@ func (c *QQClient) buildGroupMemberInfoRequestPacket(groupCode, uin int64) (uint
 
 // MessageSvc.PbGetMsg
 func (c *QQClient) buildGetMessageRequestPacket(flag msg.SyncFlag, msgTime int64) (uint16, []byte) {
-	cook := c.syncCookie
+	cook := c.sig.SyncCookie
 	if cook == nil {
 		cook, _ = proto.Marshal(&msg.SyncCookie{
 			Time:   &msgTime,
@@ -1075,7 +1152,7 @@ func (c *QQClient) buildAppInfoRequestPacket(id string) (uint16, []byte) {
 		TraceId:    proto.String(fmt.Sprintf("%v_%v_%v", c.Uin, time.Now().Format("0102150405"), rand.Int63())),
 	}
 	payload, _ := proto.Marshal(body)
-	packet := packets.BuildUniPacket(c.Uin, seq, "LightAppSvc.mini_app_info.GetAppInfoById", 1, c.OutGoingPacketSessionId, EmptyBytes, c.sigInfo.d2Key, payload)
+	packet := packets.BuildUniPacket(c.Uin, seq, "LightAppSvc.mini_app_info.GetAppInfoById", 1, c.SessionId, EmptyBytes, c.sigInfo.d2Key, payload)
 	return seq, packet
 }
 */
diff --git a/client/c2c_processor.go b/client/c2c_processor.go
index beec05ca..f8d9f65c 100644
--- a/client/c2c_processor.go
+++ b/client/c2c_processor.go
@@ -40,8 +40,8 @@ const (
 )
 
 func (c *QQClient) c2cMessageSyncProcessor(rsp *msg.GetMessageResponse, info *network.IncomingPacketInfo) {
-	c.syncCookie = rsp.SyncCookie
-	c.pubAccountCookie = rsp.PubAccountCookie
+	c.sig.SyncCookie = rsp.SyncCookie
+	c.sig.PubAccountCookie = rsp.PubAccountCookie
 	// c.msgCtrlBuf = rsp.MsgCtrlBuf
 	if rsp.UinPairMsgs == nil {
 		return
diff --git a/client/client.go b/client/client.go
index 652054c9..1f986ac5 100644
--- a/client/client.go
+++ b/client/client.go
@@ -20,7 +20,6 @@ import (
 	"github.com/Mrs4s/MiraiGo/client/internal/network"
 	"github.com/Mrs4s/MiraiGo/client/pb/msg"
 	"github.com/Mrs4s/MiraiGo/internal/crypto"
-	"github.com/Mrs4s/MiraiGo/internal/packets"
 	"github.com/Mrs4s/MiraiGo/utils"
 )
 
@@ -48,11 +47,13 @@ type QQClient struct {
 	GuildService  *GuildService
 
 	// protocol public field
-	SequenceId              atomic.Int32
-	OutGoingPacketSessionId []byte
-	RandomKey               []byte
-	TCP                     *network.TCPListener // todo: combine other protocol state into one struct
-	ConnectTime             time.Time
+	SequenceId  atomic.Int32
+	SessionId   []byte
+	RandomKey   []byte
+	TCP         *network.TCPListener // todo: combine other protocol state into one struct
+	ConnectTime time.Time
+
+	transport *network.Transport
 
 	// internal state
 	handlers        HandlerMap
@@ -65,29 +66,10 @@ type QQClient struct {
 	alive           bool
 	ecdh            *crypto.EncryptECDH
 
-	// tlv cache
-	t104     []byte
-	t174     []byte
-	g        []byte
-	t402     []byte
-	randSeed []byte // t403
-	// rollbackSig []byte
-	// t149        []byte
-	// t150        []byte
-	// t528        []byte
-	// t530        []byte
-
-	// sync info
-	syncCookie       []byte
-	pubAccountCookie []byte
-	ksid             []byte
-	// msgCtrlBuf       []byte
-
 	// session info
 	qwebSeq        atomic.Int64
-	sigInfo        *auth.SigInfo
+	sig            *auth.SigInfo
 	highwaySession *highway.Session
-	dpwd           []byte
 	// pwdFlag        bool
 	// timeDiff       int64
 
@@ -176,22 +158,33 @@ func NewClientEmpty() *QQClient {
 
 func NewClientMd5(uin int64, passwordMd5 [16]byte) *QQClient {
 	cli := &QQClient{
-		Uin:                     uin,
-		PasswordMd5:             passwordMd5,
-		AllowSlider:             true,
-		RandomKey:               make([]byte, 16),
-		OutGoingPacketSessionId: []byte{0x02, 0xB0, 0x5B, 0x8B},
-		TCP:                     &network.TCPListener{},
-		sigInfo:                 &auth.SigInfo{},
-		eventHandlers:           &eventHandlers{},
-		msgSvcCache:             utils.NewCache(time.Second * 15),
-		transCache:              utils.NewCache(time.Second * 15),
-		onlinePushCache:         utils.NewCache(time.Second * 15),
-		servers:                 []*net.TCPAddr{},
-		alive:                   true,
-		ecdh:                    crypto.NewEcdh(),
-		highwaySession:          new(highway.Session),
+		Uin:         uin,
+		PasswordMd5: passwordMd5,
+		AllowSlider: true,
+		RandomKey:   make([]byte, 16),
+		TCP:         &network.TCPListener{},
+		sig: &auth.SigInfo{
+			OutPacketSessionID: []byte{0x02, 0xB0, 0x5B, 0x8B},
+		},
+		eventHandlers:   &eventHandlers{},
+		msgSvcCache:     utils.NewCache(time.Second * 15),
+		transCache:      utils.NewCache(time.Second * 15),
+		onlinePushCache: utils.NewCache(time.Second * 15),
+		servers:         []*net.TCPAddr{},
+		alive:           true,
+		ecdh:            crypto.NewEcdh(),
+		highwaySession:  new(highway.Session),
+
+		version:    new(auth.AppVersion),
+		deviceInfo: new(auth.Device),
 	}
+
+	cli.transport = &network.Transport{
+		Sig:     cli.sig,
+		Version: cli.version,
+		Device:  cli.deviceInfo,
+	}
+
 	{ // init atomic values
 		cli.SequenceId.Store(0x3635)
 		cli.requestPacketRequestID.Store(1921334513)
@@ -256,10 +249,10 @@ func NewClientMd5(uin int64, passwordMd5 [16]byte) *QQClient {
 }
 
 func (c *QQClient) UseDevice(info *auth.Device) {
-	c.version = info.Protocol.Version()
+	*c.version = *info.Protocol.Version()
+	*c.deviceInfo = *info
 	c.highwaySession.AppID = int32(c.version.AppId)
-	c.ksid = []byte(fmt.Sprintf("|%s|A8.2.7.27f6ea96", info.IMEI))
-	c.deviceInfo = info
+	c.sig.Ksid = []byte(fmt.Sprintf("|%s|A8.2.7.27f6ea96", info.IMEI))
 }
 
 func (c *QQClient) Release() {
@@ -301,14 +294,14 @@ func (c *QQClient) TokenLogin(token []byte) error {
 	{
 		r := binary.NewReader(token)
 		c.Uin = r.ReadInt64()
-		c.sigInfo.D2 = r.ReadBytesShort()
-		c.sigInfo.D2Key = r.ReadBytesShort()
-		c.sigInfo.TGT = r.ReadBytesShort()
-		c.sigInfo.SrmToken = r.ReadBytesShort()
-		c.sigInfo.T133 = r.ReadBytesShort()
-		c.sigInfo.EncryptedA1 = r.ReadBytesShort()
-		c.sigInfo.WtSessionTicketKey = r.ReadBytesShort()
-		c.OutGoingPacketSessionId = r.ReadBytesShort()
+		c.sig.D2 = r.ReadBytesShort()
+		c.sig.D2Key = r.ReadBytesShort()
+		c.sig.TGT = r.ReadBytesShort()
+		c.sig.SrmToken = r.ReadBytesShort()
+		c.sig.T133 = r.ReadBytesShort()
+		c.sig.EncryptedA1 = r.ReadBytesShort()
+		c.sig.WtSessionTicketKey = r.ReadBytesShort()
+		c.sig.OutPacketSessionID = r.ReadBytesShort()
 		// SystemDeviceInfo.TgtgtKey = r.ReadBytesShort()
 		c.deviceInfo.TgtgtKey = r.ReadBytesShort()
 	}
@@ -406,7 +399,7 @@ func (c *QQClient) RequestSMS() bool {
 }
 
 func (c *QQClient) init(tokenLogin bool) error {
-	if len(c.g) == 0 {
+	if len(c.sig.G) == 0 {
 		c.Warning("device lock is disable. http api may fail.")
 	}
 	c.highwaySession.Uin = strconv.FormatInt(c.Uin, 10)
@@ -449,14 +442,14 @@ func (c *QQClient) init(tokenLogin bool) error {
 func (c *QQClient) GenToken() []byte {
 	return binary.NewWriterF(func(w *binary.Writer) {
 		w.WriteUInt64(uint64(c.Uin))
-		w.WriteBytesShort(c.sigInfo.D2)
-		w.WriteBytesShort(c.sigInfo.D2Key)
-		w.WriteBytesShort(c.sigInfo.TGT)
-		w.WriteBytesShort(c.sigInfo.SrmToken)
-		w.WriteBytesShort(c.sigInfo.T133)
-		w.WriteBytesShort(c.sigInfo.EncryptedA1)
-		w.WriteBytesShort(c.sigInfo.WtSessionTicketKey)
-		w.WriteBytesShort(c.OutGoingPacketSessionId)
+		w.WriteBytesShort(c.sig.D2)
+		w.WriteBytesShort(c.sig.D2Key)
+		w.WriteBytesShort(c.sig.TGT)
+		w.WriteBytesShort(c.sig.SrmToken)
+		w.WriteBytesShort(c.sig.T133)
+		w.WriteBytesShort(c.sig.EncryptedA1)
+		w.WriteBytesShort(c.sig.WtSessionTicketKey)
+		w.WriteBytesShort(c.sig.OutPacketSessionID)
 		w.WriteBytesShort(c.deviceInfo.TgtgtKey)
 	})
 }
@@ -681,11 +674,11 @@ func (c *QQClient) SolveFriendRequest(req *NewFriendRequest, accept bool) {
 }
 
 func (c *QQClient) getSKey() string {
-	if c.sigInfo.SKeyExpiredTime < time.Now().Unix() && len(c.g) > 0 {
+	if c.sig.SKeyExpiredTime < time.Now().Unix() && len(c.sig.G) > 0 {
 		c.Debug("skey expired. refresh...")
 		_, _ = c.sendAndWait(c.buildRequestTgtgtNopicsigPacket())
 	}
-	return string(c.sigInfo.SKey)
+	return string(c.sig.SKey)
 }
 
 func (c *QQClient) getCookies() string {
@@ -695,7 +688,7 @@ func (c *QQClient) getCookies() string {
 func (c *QQClient) getCookiesWithDomain(domain string) string {
 	cookie := c.getCookies()
 
-	if psKey, ok := c.sigInfo.PsKeyMap[domain]; ok {
+	if psKey, ok := c.sig.PsKeyMap[domain]; ok {
 		return fmt.Sprintf("%s p_uin=o%d; p_skey=%s;", cookie, c.Uin, psKey)
 	} else {
 		return cookie
@@ -800,8 +793,15 @@ func (c *QQClient) doHeartbeat() {
 	for c.Online.Load() {
 		time.Sleep(time.Second * 30)
 		seq := c.nextSeq()
-		sso := packets.BuildSsoPacket(seq, c.version.AppId, c.version.SubAppId, "Heartbeat.Alive", c.deviceInfo.IMEI, EmptyBytes, c.OutGoingPacketSessionId, EmptyBytes, c.ksid)
-		packet := packets.BuildLoginPacket(c.Uin, 0, EmptyBytes, sso, EmptyBytes)
+		req := network.Request{
+			Type:        network.RequestTypeLogin,
+			EncryptType: network.EncryptTypeNoEncrypt,
+			SequenceID:  int32(seq),
+			Uin:         c.Uin,
+			CommandName: "wtlogin.login",
+			Body:        EmptyBytes,
+		}
+		packet := c.transport.PackPacket(&req)
 		_, err := c.sendAndWait(seq, packet)
 		if errors.Is(err, network.ErrConnectionClosed) {
 			continue
diff --git a/client/decoders.go b/client/decoders.go
index ee6ea8d6..2037cb51 100644
--- a/client/decoders.go
+++ b/client/decoders.go
@@ -39,10 +39,10 @@ func decodeLoginResponse(c *QQClient, _ *network.IncomingPacketInfo, payload []b
 	reader.ReadUInt16()
 	m := reader.ReadTlvMap(2)
 	if m.Exists(0x402) {
-		c.dpwd = []byte(utils.RandomString(16))
-		c.t402 = m[0x402]
-		h := md5.Sum(append(append(c.deviceInfo.Guid, c.dpwd...), c.t402...))
-		c.g = h[:]
+		c.sig.Dpwd = []byte(utils.RandomString(16))
+		c.sig.T402 = m[0x402]
+		h := md5.Sum(append(append(c.deviceInfo.Guid, c.sig.Dpwd...), c.sig.T402...))
+		c.sig.G = h[:]
 	}
 	if t == 0 { // login success
 		// if t150, ok := m[0x150]; ok {
@@ -52,7 +52,7 @@ func decodeLoginResponse(c *QQClient, _ *network.IncomingPacketInfo, payload []b
 			c.decodeT161(t161)
 		}
 		if m.Exists(0x403) {
-			c.randSeed = m[0x403]
+			c.sig.RandSeed = m[0x403]
 		}
 		c.decodeT119(m[0x119], c.deviceInfo.TgtgtKey)
 		return LoginResponse{
@@ -60,7 +60,7 @@ func decodeLoginResponse(c *QQClient, _ *network.IncomingPacketInfo, payload []b
 		}, nil
 	}
 	if t == 2 {
-		c.t104 = m[0x104]
+		c.sig.T104 = m[0x104]
 		if m.Exists(0x192) {
 			return LoginResponse{
 				Success:   false,
@@ -97,9 +97,9 @@ func decodeLoginResponse(c *QQClient, _ *network.IncomingPacketInfo, payload []b
 
 	if t == 160 || t == 239 {
 		if t174, ok := m[0x174]; ok { // 短信验证
-			c.t104 = m[0x104]
-			c.t174 = t174
-			c.randSeed = m[0x403]
+			c.sig.T104 = m[0x104]
+			c.sig.T174 = t174
+			c.sig.RandSeed = m[0x403]
 			phone := func() string {
 				r := binary.NewReader(m[0x178])
 				return r.ReadStringLimit(int(r.ReadInt32()))
@@ -122,7 +122,7 @@ func decodeLoginResponse(c *QQClient, _ *network.IncomingPacketInfo, payload []b
 		}
 
 		if _, ok := m[0x17b]; ok { // 二次验证
-			c.t104 = m[0x104]
+			c.sig.T104 = m[0x104]
 			return LoginResponse{
 				Success: false,
 				Error:   SMSNeededError,
@@ -146,8 +146,8 @@ func decodeLoginResponse(c *QQClient, _ *network.IncomingPacketInfo, payload []b
 	}
 
 	if t == 204 {
-		c.t104 = m[0x104]
-		c.randSeed = m[0x403]
+		c.sig.T104 = m[0x104]
+		c.sig.RandSeed = m[0x403]
 		return c.sendAndWait(c.buildDeviceLockLoginPacket())
 	} // drive lock
 
@@ -210,7 +210,7 @@ func decodeExchangeEmpResponse(c *QQClient, _ *network.IncomingPacketInfo, paylo
 		c.decodeT119R(m[0x119])
 	}
 	if cmd == 11 {
-		h := md5.Sum(c.sigInfo.D2Key)
+		h := md5.Sum(c.sig.D2Key)
 		c.decodeT119(m[0x119], h[:])
 	}
 	return nil, nil
diff --git a/client/guild.go b/client/guild.go
index a1852ae4..2adbadde 100644
--- a/client/guild.go
+++ b/client/guild.go
@@ -663,7 +663,7 @@ func (s *GuildService) fetchChannelListState(guildId uint64, channels []*Channel
 			2: ids,
 		},
 	})
-	packet := packets.BuildUniPacket(s.c.Uin, seq, "OidbSvcTrpcTcp.0x1008_1", 1, s.c.OutGoingPacketSessionId, []byte{}, s.c.sigInfo.d2Key, payload)
+	packet := packets.BuildUniPacket(s.c.Uin, seq, "OidbSvcTrpcTcp.0x1008_1", 1, s.c.SessionId, []byte{}, s.c.sigInfo.d2Key, payload)
 	rsp, err := s.c.sendAndWaitDynamic(seq, packet)
 	if err != nil {
 		return
diff --git a/client/internal/auth/auth.go b/client/internal/auth/auth.go
index 65d45a6d..2afc9746 100644
--- a/client/internal/auth/auth.go
+++ b/client/internal/auth/auth.go
@@ -127,4 +127,26 @@ type SigInfo struct {
 
 	PsKeyMap    map[string][]byte
 	Pt4TokenMap map[string][]byte
+
+	// Others
+	OutPacketSessionID []byte
+	Dpwd               []byte
+
+	// tlv cache
+	T104     []byte
+	T174     []byte
+	G        []byte
+	T402     []byte
+	RandSeed []byte // t403
+	// rollbackSig []byte
+	// t149        []byte
+	// t150        []byte
+	// t528        []byte
+	// t530        []byte
+
+	// sync info
+	SyncCookie       []byte
+	PubAccountCookie []byte
+	Ksid             []byte
+	// msgCtrlBuf       []byte
 }
diff --git a/client/internal/codec/uni.go b/client/internal/codec/uni.go
deleted file mode 100644
index 9a2ad449..00000000
--- a/client/internal/codec/uni.go
+++ /dev/null
@@ -1,41 +0,0 @@
-package codec
-
-import (
-	"strconv"
-
-	"github.com/Mrs4s/MiraiGo/binary"
-)
-
-type Uni struct {
-	Uin         int64
-	Seq         uint16
-	CommandName string
-	EncryptType byte
-	SessionID   []byte
-	ExtraData   []byte
-	Key         []byte
-	Body        []byte
-}
-
-func (u *Uni) Encode() []byte {
-	return binary.NewWriterF(func(w *binary.Writer) {
-		w2 := binary.SelectWriter()
-		{ // w.WriteIntLvPacket
-			w2.WriteUInt32(0x0B)
-			w2.WriteByte(u.EncryptType)
-			w2.WriteUInt32(uint32(u.Seq))
-			w2.WriteByte(0)
-			w2.WriteString(strconv.FormatInt(u.Uin, 10))
-
-			// inline NewWriterF
-			w3 := binary.SelectWriter()
-			w3.WriteUniPacket(u.CommandName, u.SessionID, u.ExtraData, u.Body)
-			w2.EncryptAndWrite(u.Key, w3.Bytes())
-			binary.PutWriter(w3)
-		}
-		data := w2.Bytes()
-		w.WriteUInt32(uint32(len(data) + 4))
-		w.Write(data)
-		binary.PutWriter(w2)
-	})
-}
diff --git a/client/internal/network/request.go b/client/internal/network/request.go
index 88ff01f0..b34930f5 100644
--- a/client/internal/network/request.go
+++ b/client/internal/network/request.go
@@ -22,6 +22,6 @@ type Request struct {
 	EncryptType EncryptType
 	SequenceID  int32
 	Uin         int64
-	Method      string
+	CommandName string
 	Body        []byte
 }
diff --git a/client/internal/network/transport.go b/client/internal/network/transport.go
index 4bc4de87..e5dc468c 100644
--- a/client/internal/network/transport.go
+++ b/client/internal/network/transport.go
@@ -11,95 +11,96 @@ import (
 // Transport is a network transport.
 type Transport struct {
 	sessionMu sync.Mutex
-	// todo: combine session fields to a struct
-	tgt       []byte
-	d2key     []byte
-	sessionID []byte
-	ksid      []byte
-
-	version *auth.AppVersion
-	device  *auth.Device
+	Sig       *auth.SigInfo
+	Version   *auth.AppVersion
+	Device    *auth.Device
 
 	// connection
-	conn *TCPListener
+	// conn *TCPListener
 }
 
-func (t *Transport) packBody(req *Request, w *binary.Writer) {
+func (t *Transport) packBody(req *Request) []byte {
+	w := binary.SelectWriter()
+	defer binary.PutWriter(w)
 	w.WriteIntLvPacket(4, func(writer *binary.Writer) {
 		if req.Type == RequestTypeLogin {
 			writer.WriteUInt32(uint32(req.SequenceID))
-			writer.WriteUInt32(t.version.AppId)
-			writer.WriteUInt32(t.version.SubAppId)
+			writer.WriteUInt32(t.Version.AppId)
+			writer.WriteUInt32(t.Version.SubAppId)
 			writer.Write([]byte{0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00})
-			if len(t.tgt) == 0 || len(t.tgt) == 4 {
+			tgt := t.Sig.TGT
+			if len(tgt) == 0 || len(tgt) == 4 {
 				writer.WriteUInt32(0x04)
 			} else {
-				writer.WriteUInt32(uint32(len(t.tgt) + 4))
-				writer.Write(t.tgt)
+				writer.WriteUInt32(uint32(len(tgt) + 4))
+				writer.Write(tgt)
 			}
 		}
-
-		writer.WriteString(req.Method)
-		writer.WriteUInt32(uint32(len(t.sessionID) + 4))
-		w.Write(t.sessionID)
+		writer.WriteString(req.CommandName)
+		writer.WriteIntLvPacket(4, func(w *binary.Writer) {
+			w.Write(t.Sig.OutPacketSessionID)
+		})
+		// writer.WriteUInt32(uint32(len(t.Sig.OutPacketSessionID) + 4))
+		// w.Write(t.Sig.OutPacketSessionID)
 		if req.Type == RequestTypeLogin {
-			writer.WriteString(t.device.IMEI)
+			writer.WriteString(t.Device.IMEI)
 			writer.WriteUInt32(0x04)
 			{
-				writer.WriteUInt16(uint16(len(t.ksid)) + 2)
-				writer.Write(t.ksid)
+				writer.WriteUInt16(uint16(len(t.Sig.Ksid)) + 2)
+				writer.Write(t.Sig.Ksid)
 			}
 		}
 		writer.WriteUInt32(0x04)
 	})
 
-	w.WriteUInt32(uint32(len(req.Body) + 4))
-	w.Write(req.Body)
+	w.WriteIntLvPacket(4, func(w *binary.Writer) {
+		w.Write(req.Body)
+	})
+	// w.WriteUInt32(uint32(len(req.Body) + 4))
+	// w.Write(req.Body)
+	return append([]byte(nil), w.Bytes()...)
 }
 
-func (t *Transport) Send(req *Request) error {
-	// todo: return response
+// PackPacket packs a packet.
+func (t *Transport) PackPacket(req *Request) []byte {
+	// todo(wdvxdr): combine pack packet, send packet and return the response
+	if len(t.Sig.D2) == 0 {
+		req.EncryptType = EncryptTypeEmptyKey
+	}
+	body := t.packBody(req)
+	// encrypt body
+	switch req.EncryptType {
+	case EncryptTypeD2Key:
+		body = binary.NewTeaCipher(t.Sig.D2Key).Encrypt(body)
+	case EncryptTypeEmptyKey:
+		body = binary.NewTeaCipher(emptyKey).Encrypt(body)
+	}
+
 	head := binary.NewWriterF(func(w *binary.Writer) {
 		w.WriteUInt32(uint32(req.Type))
-		w.WriteUInt32(uint32(req.EncryptType))
+		w.WriteByte(byte(req.EncryptType))
 		switch req.Type {
 		case RequestTypeLogin:
 			switch req.EncryptType {
 			case EncryptTypeD2Key:
-				w.WriteUInt32(uint32(len(t.d2key) + 4))
-				w.Write(t.d2key)
+				w.WriteUInt32(uint32(len(t.Sig.D2) + 4))
+				w.Write(t.Sig.D2)
 			default:
 				w.WriteUInt32(4)
 			}
 		case RequestTypeSimple:
 			w.WriteUInt32(uint32(req.SequenceID))
 		}
+		w.WriteByte(0x00)
 		w.WriteString(strconv.FormatInt(req.Uin, 10))
 	})
 
 	w := binary.SelectWriter()
 	defer binary.PutWriter(w)
-	t.packBody(req, w)
-	body := w.Bytes()
-
-	// encrypt body
-	switch req.EncryptType {
-	case EncryptTypeD2Key:
-		body = binary.NewTeaCipher(t.d2key).Encrypt(body)
-	case EncryptTypeEmptyKey:
-		body = binary.NewTeaCipher(emptyKey).Encrypt(body)
-	}
-
-	w2 := binary.SelectWriter()
-	defer binary.PutWriter(w2)
-	w2.WriteUInt32(uint32(len(head) + len(body) + 4))
-	w2.Write(head)
-	w2.Write(body)
-	err := t.conn.Write(w2.Bytes())
-	if err != nil {
-		return err
-	}
-	return nil
+	w.WriteUInt32(uint32(len(head)+len(body)) + 4)
+	w.Write(head)
+	w.Write(body)
+	return append([]byte(nil), w.Bytes()...) // copy
 }
 
 func (t *Transport) parse(head []byte) *Request {
@@ -119,7 +120,7 @@ func (t *Transport) parse(head []byte) *Request {
 	case EncryptTypeNoEncrypt:
 		req.Body = body
 	case EncryptTypeD2Key:
-		req.Body = binary.NewTeaCipher(t.d2key).Decrypt(body)
+		req.Body = binary.NewTeaCipher(t.Sig.D2Key).Decrypt(body)
 	case EncryptTypeEmptyKey:
 		req.Body = binary.NewTeaCipher(emptyKey).Decrypt(body)
 	}
diff --git a/client/model_show.go b/client/model_show.go
index 465453b8..6b77a43b 100644
--- a/client/model_show.go
+++ b/client/model_show.go
@@ -42,7 +42,7 @@ type (
 )
 
 func (c *QQClient) getGtk(domain string) int {
-	if psKey, ok := c.sigInfo.PsKeyMap[domain]; ok {
+	if psKey, ok := c.sig.PsKeyMap[domain]; ok {
 		accu := 5381
 		for _, b := range psKey {
 			accu = accu + (accu << 5) + int(b)
diff --git a/client/network.go b/client/network.go
index fc5eab50..c94a539a 100644
--- a/client/network.go
+++ b/client/network.go
@@ -291,7 +291,7 @@ func (c *QQClient) netLoop() {
 			continue
 		}
 		data, _ := c.TCP.ReadBytes(int(l) - 4)
-		pkt, err := packets.ParseIncomingPacket(data, c.sigInfo.D2Key)
+		pkt, err := packets.ParseIncomingPacket(data, c.sig.D2Key)
 		if err != nil {
 			c.Error("parse incoming packet error: %v", err)
 			if errors.Is(err, packets.ErrSessionExpired) || errors.Is(err, packets.ErrPacketDropped) {
@@ -306,7 +306,7 @@ func (c *QQClient) netLoop() {
 			continue
 		}
 		if pkt.Flag2 == 2 {
-			pkt.Payload, err = pkt.DecryptPayload(c.ecdh.InitialShareKey, c.RandomKey, c.sigInfo.WtSessionTicketKey)
+			pkt.Payload, err = pkt.DecryptPayload(c.ecdh.InitialShareKey, c.RandomKey, c.sig.WtSessionTicketKey)
 			if err != nil {
 				c.Error("decrypt payload error: %v", err)
 				if errors.Is(err, packets.ErrUnknownFlag) {
diff --git a/client/packet.go b/client/packet.go
index 37fbe1ab..8261b2d8 100644
--- a/client/packet.go
+++ b/client/packet.go
@@ -2,6 +2,7 @@ package client
 
 import (
 	"github.com/Mrs4s/MiraiGo/client/internal/codec"
+	"github.com/Mrs4s/MiraiGo/client/internal/network"
 )
 
 //go:noinline
@@ -19,30 +20,26 @@ func (c *QQClient) buildOicqRequestPacket(uin int64, command uint16, body []byte
 //go:noinline
 func (c *QQClient) uniPacket(command string, body []byte) (uint16, []byte) {
 	seq := c.nextSeq()
-	req := codec.Uni{
+	req := network.Request{
+		Type:        network.RequestTypeSimple,
+		EncryptType: network.EncryptTypeD2Key,
 		Uin:         c.Uin,
-		Seq:         seq,
+		SequenceID:  int32(seq),
 		CommandName: command,
-		EncryptType: 1,
-		SessionID:   c.OutGoingPacketSessionId,
-		ExtraData:   EmptyBytes,
-		Key:         c.sigInfo.D2Key,
 		Body:        body,
 	}
-	return seq, req.Encode()
+	return seq, c.transport.PackPacket(&req)
 }
 
 //go:noinline
 func (c *QQClient) uniPacketWithSeq(seq uint16, command string, body []byte) []byte {
-	req := codec.Uni{
+	req := network.Request{
+		Type:        network.RequestTypeSimple,
+		EncryptType: network.EncryptTypeD2Key,
 		Uin:         c.Uin,
-		Seq:         seq,
+		SequenceID:  int32(seq),
 		CommandName: command,
-		EncryptType: 1,
-		SessionID:   c.OutGoingPacketSessionId,
-		ExtraData:   EmptyBytes,
-		Key:         c.sigInfo.D2Key,
 		Body:        body,
 	}
-	return req.Encode()
+	return c.transport.PackPacket(&req)
 }
diff --git a/client/private_msg.go b/client/private_msg.go
index 45e567de..22c7e3b1 100644
--- a/client/private_msg.go
+++ b/client/private_msg.go
@@ -139,7 +139,7 @@ func (c *QQClient) buildGetOneDayRoamMsgRequest(target, lastMsgTime, random int6
 		ReadCnt:     &count,
 	}
 	payload, _ := proto.Marshal(req)
-	packet := packets.BuildUniPacket(c.Uin, seq, "MessageSvc.PbGetOneDayRoamMsg", 1, c.OutGoingPacketSessionId, EmptyBytes, c.sigInfo.d2Key, payload)
+	packet := packets.BuildUniPacket(c.Uin, seq, "MessageSvc.PbGetOneDayRoamMsg", 1, c.SessionId, EmptyBytes, c.sigInfo.d2Key, payload)
 	return seq, packet
 }
 */
diff --git a/client/sync.go b/client/sync.go
index 470b09e8..362cfd19 100644
--- a/client/sync.go
+++ b/client/sync.go
@@ -157,11 +157,11 @@ func (c *QQClient) buildGetOfflineMsgRequestPacket() (uint16, []byte) {
 			Channel:          4,
 			Inst:             1,
 			ChannelEx:        1,
-			SyncCookie:       c.syncCookie,
+			SyncCookie:       c.sig.SyncCookie,
 			SyncFlag:         0, // START
 			RambleFlag:       0,
 			GeneralAbi:       1,
-			PubAccountCookie: c.pubAccountCookie,
+			PubAccountCookie: c.sig.PubAccountCookie,
 		},
 		GroupMsg: &jce.SvcReqPullGroupMsgSeq{
 			VerifyType: 0,
@@ -172,7 +172,7 @@ func (c *QQClient) buildGetOfflineMsgRequestPacket() (uint16, []byte) {
 	flag := msg.SyncFlag_START
 	msgReq, _ := proto.Marshal(&msg.GetMessageRequest{
 		SyncFlag:           &flag,
-		SyncCookie:         c.syncCookie,
+		SyncCookie:         c.sig.SyncCookie,
 		RambleFlag:         proto.Int32(0),
 		ContextFlag:        proto.Int32(1),
 		OnlineSyncFlag:     proto.Int32(0),
@@ -224,11 +224,11 @@ func (c *QQClient) buildSyncMsgRequestPacket() (uint16, []byte) {
 			Channel:          4,
 			Inst:             1,
 			ChannelEx:        1,
-			SyncCookie:       c.syncCookie,
+			SyncCookie:       c.sig.SyncCookie,
 			SyncFlag:         0, // START
 			RambleFlag:       0,
 			GeneralAbi:       1,
-			PubAccountCookie: c.pubAccountCookie,
+			PubAccountCookie: c.sig.PubAccountCookie,
 		},
 		GroupMask: 2,
 		EndSeq:    int64(rand.Uint32()),
@@ -237,7 +237,7 @@ func (c *QQClient) buildSyncMsgRequestPacket() (uint16, []byte) {
 	flag := msg.SyncFlag_START
 	msgReq := &msg.GetMessageRequest{
 		SyncFlag:           &flag,
-		SyncCookie:         c.syncCookie,
+		SyncCookie:         c.sig.SyncCookie,
 		RambleFlag:         proto.Int32(0),
 		ContextFlag:        proto.Int32(1),
 		OnlineSyncFlag:     proto.Int32(0),
@@ -248,7 +248,7 @@ func (c *QQClient) buildSyncMsgRequestPacket() (uint16, []byte) {
 	offMsg, _ := proto.Marshal(msgReq)
 	msgReq.MsgReqType = proto.Int32(2)
 	msgReq.SyncCookie = nil
-	msgReq.PubaccountCookie = c.pubAccountCookie
+	msgReq.PubaccountCookie = c.sig.PubAccountCookie
 	pubMsg, _ := proto.Marshal(msgReq)
 	buf := &jce.RequestDataVersion3{Map: map[string][]byte{
 		"req_PbOffMsg": jce.NewJceWriter().WriteBytes(append([]byte{0, 0, 0, 0}, offMsg...), 0).Bytes(),
@@ -280,7 +280,7 @@ func (c *QQClient) buildPrivateMsgReadedPacket(uin, time int64) (uint16, []byte)
 			PeerUin:      proto.Uint64(uint64(uin)),
 			LastReadTime: proto.Uint32(uint32(time)),
 		},
-	}, SyncCookie: c.syncCookie}})
+	}, SyncCookie: c.sig.SyncCookie}})
 	return c.uniPacket("PbMessageSvc.PbMsgReadedReport", req)
 }
 
diff --git a/client/tlv_decoders.go b/client/tlv_decoders.go
index 7df0828c..64112e98 100644
--- a/client/tlv_decoders.go
+++ b/client/tlv_decoders.go
@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/Mrs4s/MiraiGo/client/internal/auth"
 	"github.com/Mrs4s/MiraiGo/utils"
 
 	"github.com/Mrs4s/MiraiGo/binary"
@@ -44,7 +43,7 @@ func (c *QQClient) decodeT119(data, ek []byte) {
 		}
 	*/
 	if t108, ok := m[0x108]; ok {
-		c.ksid = t108
+		c.sig.Ksid = t108
 	}
 
 	var (
@@ -91,29 +90,28 @@ func (c *QQClient) decodeT119(data, ek []byte) {
 	}
 
 	// we don't use `c.sigInfo = &auth.SigInfo{...}` here,
-	// because we need spread `SigInfo` to other places
-	*c.sigInfo = auth.SigInfo{
-		LoginBitmap:        0,
-		SrmToken:           utils.Select(m[0x16a], c.sigInfo.SrmToken),
-		T133:               utils.Select(m[0x133], c.sigInfo.T133),
-		EncryptedA1:        utils.Select(m[0x106], c.sigInfo.EncryptedA1),
-		TGT:                m[0x10a],
-		TGTKey:             m[0x10d],
-		UserStKey:          m[0x10e],
-		UserStWebSig:       m[0x103],
-		SKey:               m[0x120],
-		SKeyExpiredTime:    time.Now().Unix() + 21600,
-		D2:                 m[0x143],
-		D2Key:              m[0x305],
-		WtSessionTicketKey: utils.Select(m[0x134], c.sigInfo.WtSessionTicketKey),
-		DeviceToken:        m[0x322],
+	// because we need keep other fields in `c.sigInfo`
+	s := c.sig
+	s.LoginBitmap = 0
+	s.SrmToken = utils.Select(m[0x16a], s.SrmToken)
+	s.T133 = utils.Select(m[0x133], s.T133)
+	s.EncryptedA1 = utils.Select(m[0x106], s.EncryptedA1)
+	s.TGT = m[0x10a]
+	s.TGTKey = m[0x10d]
+	s.UserStKey = m[0x10e]
+	s.UserStWebSig = m[0x103]
+	s.SKey = m[0x120]
+	s.SKeyExpiredTime = time.Now().Unix() + 21600
+	s.D2 = m[0x143]
+	s.D2Key = m[0x305]
+	s.WtSessionTicketKey = utils.Select(m[0x134], s.WtSessionTicketKey)
+	s.DeviceToken = m[0x322]
 
-		PsKeyMap:    psKeyMap,
-		Pt4TokenMap: pt4TokenMap,
-	}
+	s.PsKeyMap = psKeyMap
+	s.Pt4TokenMap = pt4TokenMap
 	if len(c.PasswordMd5[:]) > 0 {
 		key := md5.Sum(append(append(c.PasswordMd5[:], []byte{0x00, 0x00, 0x00, 0x00}...), binary.NewWriterF(func(w *binary.Writer) { w.WriteUInt32(uint32(c.Uin)) })...))
-		decrypted := binary.NewTeaCipher(key[:]).Decrypt(c.sigInfo.EncryptedA1)
+		decrypted := binary.NewTeaCipher(key[:]).Decrypt(c.sig.EncryptedA1)
 		if len(decrypted) > 51+16 {
 			dr := binary.NewReader(decrypted)
 			dr.ReadBytes(51)
@@ -132,9 +130,9 @@ func (c *QQClient) decodeT119R(data []byte) {
 	reader.ReadBytes(2)
 	m := reader.ReadTlvMap(2)
 	if t120, ok := m[0x120]; ok {
-		c.sigInfo.SKey = t120
-		c.sigInfo.SKeyExpiredTime = time.Now().Unix() + 21600
-		c.Debug("skey updated: %v", c.sigInfo.SKey)
+		c.sig.SKey = t120
+		c.sig.SKeyExpiredTime = time.Now().Unix() + 21600
+		c.Debug("skey updated: %v", c.sig.SKey)
 	}
 	if t11a, ok := m[0x11a]; ok {
 		c.Nickname, c.Age, c.Gender = readT11A(t11a)
diff --git a/internal/packets/builders.go b/internal/packets/builders.go
deleted file mode 100644
index 8e51e9d3..00000000
--- a/internal/packets/builders.go
+++ /dev/null
@@ -1,26 +0,0 @@
-package packets
-
-import (
-	"strconv"
-
-	"github.com/Mrs4s/MiraiGo/binary"
-)
-
-func BuildLoginPacket(uin int64, bodyType byte, key, body, extraData []byte) []byte {
-	return binary.NewWriterF(func(w *binary.Writer) {
-		w.WriteIntLvPacket(4, func(w *binary.Writer) {
-			w.WriteUInt32(0x00_00_00_0A)
-			w.WriteByte(bodyType)
-			w.WriteIntLvPacket(4, func(w *binary.Writer) {
-				w.Write(extraData)
-			})
-			w.WriteByte(0x00)
-			w.WriteString(strconv.FormatInt(uin, 10))
-			if len(key) == 0 {
-				w.Write(body)
-			} else {
-				w.EncryptAndWrite(key, body)
-			}
-		})
-	})
-}
diff --git a/internal/packets/global.go b/internal/packets/global.go
index 109d6c24..cc2abf7f 100644
--- a/internal/packets/global.go
+++ b/internal/packets/global.go
@@ -46,38 +46,6 @@ func BuildCode2DRequestPacket(seq uint32, j uint64, cmd uint16, bodyFunc func(wr
 	})
 }
 
-func BuildSsoPacket(seq uint16, appID, subAppID uint32, commandName, imei string, extData, outPacketSessionId, body, ksid []byte) []byte {
-	return binary.NewWriterF(func(p *binary.Writer) {
-		p.WriteIntLvPacket(4, func(writer *binary.Writer) {
-			writer.WriteUInt32(uint32(seq))
-			writer.WriteUInt32(appID)
-			writer.WriteUInt32(subAppID)
-			writer.Write([]byte{0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00})
-			if len(extData) == 0 || len(extData) == 4 {
-				writer.WriteUInt32(0x04)
-			} else {
-				writer.WriteUInt32(uint32(len(extData) + 4))
-				writer.Write(extData)
-			}
-			writer.WriteString(commandName)
-			writer.WriteIntLvPacket(4, func(w *binary.Writer) {
-				w.Write(outPacketSessionId)
-			})
-			writer.WriteString(imei)
-			writer.WriteUInt32(0x04)
-			{
-				writer.WriteUInt16(uint16(len(ksid)) + 2)
-				writer.Write(ksid)
-			}
-			writer.WriteUInt32(0x04)
-		})
-
-		p.WriteIntLvPacket(4, func(writer *binary.Writer) {
-			writer.Write(body)
-		})
-	})
-}
-
 func ParseIncomingPacket(payload, d2key []byte) (*IncomingPacket, error) {
 	if len(payload) < 6 {
 		return nil, errors.WithStack(ErrInvalidPayload)