diff --git a/commonspace/sync/headupdate.go b/commonspace/sync/headupdate.go
new file mode 100644
index 00000000..d1bbdbe5
--- /dev/null
+++ b/commonspace/sync/headupdate.go
@@ -0,0 +1,95 @@
+package sync
+
+import (
+	"fmt"
+	"slices"
+
+	"github.com/gogo/protobuf/proto"
+
+	"github.com/anyproto/any-sync/commonspace/object/tree/treechangeproto"
+	"github.com/anyproto/any-sync/commonspace/spacesyncproto"
+)
+
+type HeadUpdate struct {
+	peerId       string
+	objectId     string
+	spaceId      string
+	heads        []string
+	changes      []*treechangeproto.RawTreeChangeWithId
+	snapshotPath []string
+	root         *treechangeproto.RawTreeChangeWithId
+	opts         BroadcastOptions
+}
+
+func (h *HeadUpdate) SetPeerId(peerId string) {
+	h.peerId = peerId
+}
+
+func (h *HeadUpdate) SetProtoMessage(message proto.Message) error {
+	var (
+		msg *spacesyncproto.ObjectSyncMessage
+		ok  bool
+	)
+	if msg, ok = message.(*spacesyncproto.ObjectSyncMessage); !ok {
+		return fmt.Errorf("unexpected message type: %T", message)
+	}
+	treeMsg := &treechangeproto.TreeSyncMessage{}
+	err := proto.Unmarshal(msg.Payload, treeMsg)
+	if err != nil {
+		return err
+	}
+	h.root = treeMsg.RootChange
+	headMsg := treeMsg.GetContent().GetHeadUpdate()
+	if headMsg == nil {
+		return fmt.Errorf("unexpected message type: %T", treeMsg.GetContent())
+	}
+	h.heads = headMsg.Heads
+	h.changes = headMsg.Changes
+	h.snapshotPath = headMsg.SnapshotPath
+	h.spaceId = msg.SpaceId
+	h.objectId = msg.ObjectId
+	return nil
+}
+
+func (h *HeadUpdate) ProtoMessage() (proto.Message, error) {
+	if h.heads != nil {
+		return h.SyncMessage()
+	}
+	return &spacesyncproto.ObjectSyncMessage{}, nil
+}
+
+func (h *HeadUpdate) PeerId() string {
+	return h.peerId
+}
+
+func (h *HeadUpdate) ObjectId() string {
+	return h.objectId
+}
+
+func (h *HeadUpdate) ShallowCopy() *HeadUpdate {
+	return &HeadUpdate{
+		peerId:       h.peerId,
+		objectId:     h.objectId,
+		heads:        h.heads,
+		changes:      h.changes,
+		snapshotPath: h.snapshotPath,
+		root:         h.root,
+	}
+}
+
+func (h *HeadUpdate) SyncMessage() (*spacesyncproto.ObjectSyncMessage, error) {
+	changes := h.changes
+	if slices.Contains(h.opts.EmptyPeers, h.peerId) {
+		changes = nil
+	}
+	treeMsg := treechangeproto.WrapHeadUpdate(&treechangeproto.TreeHeadUpdate{
+		Heads:        h.heads,
+		SnapshotPath: h.snapshotPath,
+		Changes:      changes,
+	}, h.root)
+	return spacesyncproto.MarshallSyncMessage(treeMsg, h.spaceId, h.objectId)
+}
+
+func (h *HeadUpdate) RemoveChanges() {
+	h.changes = nil
+}
diff --git a/commonspace/sync/headupdatehandler.go b/commonspace/sync/headupdatehandler.go
new file mode 100644
index 00000000..9064cb36
--- /dev/null
+++ b/commonspace/sync/headupdatehandler.go
@@ -0,0 +1,11 @@
+package sync
+
+import (
+	"context"
+
+	"storj.io/drpc"
+)
+
+type HeadUpdateHandler interface {
+	HandleHeadUpdate(ctx context.Context, headUpdate drpc.Message) (Request, error)
+}
diff --git a/commonspace/sync/headupdatesender.go b/commonspace/sync/headupdatesender.go
new file mode 100644
index 00000000..252b463b
--- /dev/null
+++ b/commonspace/sync/headupdatesender.go
@@ -0,0 +1,12 @@
+package sync
+
+import "context"
+
+type BroadcastOptions struct {
+	EmptyPeers []string
+}
+
+type HeadUpdateSender interface {
+	SendHeadUpdate(ctx context.Context, peerId string, headUpdate *HeadUpdate) error
+	BroadcastHeadUpdate(ctx context.Context, opts BroadcastOptions, headUpdate *HeadUpdate) error
+}
diff --git a/commonspace/sync/requestmanager.go b/commonspace/sync/requestmanager.go
new file mode 100644
index 00000000..f7fda85d
--- /dev/null
+++ b/commonspace/sync/requestmanager.go
@@ -0,0 +1,125 @@
+package sync
+
+import (
+	"context"
+	"strings"
+	"sync"
+
+	"github.com/gogo/protobuf/proto"
+	"storj.io/drpc"
+
+	"github.com/anyproto/any-sync/net/streampool"
+)
+
+type Request interface {
+	//heads   []string
+	//changes []*treechangeproto.RawTreeChangeWithId
+	//root    *treechangeproto.RawTreeChangeWithId
+}
+
+type Response interface {
+	//heads   []string
+	//changes []*treechangeproto.RawTreeChangeWithId
+	//root    *treechangeproto.RawTreeChangeWithId
+}
+
+type RequestAccepter func(ctx context.Context, resp Response) error
+
+type RequestManager interface {
+	QueueRequest(peerId, objectId string, rq Request) error
+	HandleRequest(peerId, objectId string, rq Request, accept RequestAccepter) error
+	HandleStreamRequest(peerId, objectId string, rq Request, stream drpc.Stream) error
+}
+
+type RequestHandler interface {
+	HandleRequest(peerId, objectId string, rq Request, accept RequestAccepter) error
+	HandleStreamRequest(peerId, objectId string, rq Request, send func(resp proto.Message) error) error
+}
+
+type StreamResponse struct {
+	Stream     drpc.Stream
+	Connection drpc.Conn
+}
+
+type RequestSender interface {
+	SendRequest(peerId, objectId string, rq Request) (resp Response, err error)
+	SendStreamRequest(peerId, objectId string, rq Request, receive func(stream drpc.Stream) error) (err error)
+}
+
+type ResponseHandler interface {
+	NewResponse() Response
+	HandleResponse(peerId, objectId string, resp Response) error
+}
+
+type requestManager struct {
+	requestPool     RequestPool
+	requestHandler  RequestHandler
+	responseHandler ResponseHandler
+	requestSender   RequestSender
+	currentRequests map[string]struct{}
+	mx              sync.Mutex
+	ctx             context.Context
+	cancel          context.CancelFunc
+	wait            chan struct{}
+}
+
+func (r *requestManager) QueueRequest(peerId, objectId string, rq Request) error {
+	return r.requestPool.QueueRequestAction(peerId, objectId, func() {
+		r.requestSender.SendStreamRequest(peerId, objectId, rq, func(stream drpc.Stream) error {
+			for {
+				resp := r.responseHandler.NewResponse()
+				err := stream.MsgRecv(resp, streampool.EncodingProto)
+				if err != nil {
+					return err
+				}
+				err = r.responseHandler.HandleResponse(peerId, objectId, resp)
+				if err != nil {
+					return err
+				}
+			}
+			return nil
+		})
+	})
+}
+
+func (r *requestManager) HandleRequest(peerId, objectId string, rq Request, accept RequestAccepter) error {
+	id := fullId(peerId, objectId)
+	r.mx.Lock()
+	if _, ok := r.currentRequests[id]; ok {
+		r.mx.Unlock()
+		return nil
+	}
+	r.currentRequests[id] = struct{}{}
+	r.mx.Unlock()
+	defer func() {
+		r.mx.Lock()
+		delete(r.currentRequests, id)
+		r.mx.Unlock()
+	}()
+	return r.requestHandler.HandleRequest(peerId, objectId, rq, accept)
+}
+
+func (r *requestManager) HandleStreamRequest(peerId, objectId string, rq Request, stream drpc.Stream) error {
+	id := fullId(peerId, objectId)
+	r.mx.Lock()
+	if _, ok := r.currentRequests[id]; ok {
+		r.mx.Unlock()
+		return nil
+	}
+	r.currentRequests[id] = struct{}{}
+	r.mx.Unlock()
+	defer func() {
+		r.mx.Lock()
+		delete(r.currentRequests, id)
+		r.mx.Unlock()
+	}()
+
+	err := r.requestHandler.HandleStreamRequest(peerId, objectId, rq, func(resp proto.Message) error {
+		return stream.MsgSend(resp, streampool.EncodingProto)
+	})
+	return err
+}
+
+func fullId(peerId, objectId string) string {
+	return strings.Join([]string{peerId, objectId}, "-")
+}
diff --git a/commonspace/sync/requestpool.go b/commonspace/sync/requestpool.go
new file mode 100644
index 00000000..c34944ba
--- /dev/null
+++ b/commonspace/sync/requestpool.go
@@ -0,0 +1,5 @@
+package sync
+
+type RequestPool interface {
+	QueueRequestAction(peerId, objectId string, action func()) (err error)
+}
diff --git a/commonspace/sync/sync.go b/commonspace/sync/sync.go
new file mode 100644
index 00000000..ee2a588b
--- /dev/null
+++ b/commonspace/sync/sync.go
@@ -0,0 +1,84 @@
+package sync
+
+import (
+	"context"
+
+	"github.com/cheggaaa/mb/v3"
+	"go.uber.org/zap"
+	"storj.io/drpc"
+
+	"github.com/anyproto/any-sync/app/logger"
+	"github.com/anyproto/any-sync/util/multiqueue"
+)
+
+const CName = "common.commonspace.sync"
+
+var log = logger.NewNamed("sync")
+
+type SyncService interface {
+	GetQueueProvider() multiqueue.QueueProvider[drpc.Message]
+}
+
+type MergeFilterFunc func(ctx context.Context, msg drpc.Message, q *mb.MB[drpc.Message]) error
+
+type syncService struct {
+	// sendQueue is a multiqueue: peerId -> queue
+	// this queue exists for sending head updates
+	sendQueueProvider multiqueue.QueueProvider[drpc.Message]
+	// receiveQueue is a multiqueue: objectId -> queue
+	// this queue exists for receiving head updates
+	receiveQueue multiqueue.MultiQueue[drpc.Message]
+	// manager is a Request manager which works with both incoming and outgoing requests
+	manager RequestManager
+	// handler checks if head update is relevant and then queues Request intent if necessary
+	handler HeadUpdateHandler
+	// sender sends head updates to peers
+	sender      HeadUpdateSender
+	mergeFilter MergeFilterFunc
+	ctx         context.Context
+	cancel      context.CancelFunc
+}
+
+func NewSyncService() SyncService {
+	s := &syncService{}
+	s.ctx, s.cancel = context.WithCancel(context.Background())
+	s.sendQueueProvider = multiqueue.NewQueueProvider[drpc.Message](100, s.handleOutgoingMessage)
+	s.receiveQueue = multiqueue.New[drpc.Message](s.handleIncomingMessage, 100)
+	return s
+}
+
+func (s *syncService) handleOutgoingMessage(id string, msg drpc.Message, q *mb.MB[drpc.Message]) error {
+	//headUpdate := msg.(*HeadUpdate)
+	//cp := headUpdate.ShallowCopy()
+	//cp.SetPeerId(id)
+	//// TODO: add some merging/filtering logic if needed
+	//// for example we can filter empty messages for the same peer
+	//// or we can merge the messages together
+	return s.mergeFilter(s.ctx, msg, q)
+}
+
+func (s *syncService) handleIncomingMessage(msg drpc.Message) {
+	req, err := s.handler.HandleHeadUpdate(s.ctx, msg)
+	if err != nil {
+		log.Error("failed to handle head update", zap.Error(err))
+	}
+	if req == nil {
+		return
+	}
+	err = s.manager.QueueRequest("", "", req)
+	if err != nil {
+		log.Error("failed to queue request", zap.Error(err))
+	}
+}
+
+func (s *syncService) GetQueueProvider() multiqueue.QueueProvider[drpc.Message] {
+	return s.sendQueueProvider
+}
+
+func (s *syncService) HandleMessage(ctx context.Context, peerId string, msg drpc.Message) error {
+	return s.receiveQueue.Add(ctx, peerId, msg.(*HeadUpdate))
+}
+
+func (s *syncService) NewReadMessage() drpc.Message {
+	return &HeadUpdate{}
+}
diff --git a/net/streampool/encoding.go b/net/streampool/encoding.go
index d724bf90..b494c4eb 100644
--- a/net/streampool/encoding.go
+++ b/net/streampool/encoding.go
@@ -2,6 +2,7 @@ package streampool
 
 import (
 	"errors"
+
 	"github.com/gogo/protobuf/proto"
 	"storj.io/drpc"
 )
@@ -15,20 +16,51 @@ var (
 	errNotAProtoMsg = errors.New("encoding: not a proto message")
 )
 
+type ProtoMessageGettable interface {
+	ProtoMessage() (proto.Message, error)
+}
+
+type ProtoMessageSettable interface {
+	ProtoMessageGettable
+	SetProtoMessage(proto.Message) error
+}
+
 type protoEncoding struct{}
 
-func (p protoEncoding) Marshal(msg drpc.Message) ([]byte, error) {
+func (p protoEncoding) Marshal(msg drpc.Message) (res []byte, err error) {
 	pmsg, ok := msg.(proto.Message)
 	if !ok {
-		return nil, errNotAProtoMsg
+		if pmg, ok := msg.(ProtoMessageGettable); ok {
+			pmsg, err = pmg.ProtoMessage()
+			if err != nil {
+				return nil, err
+			}
+		} else {
+			return nil, errNotAProtoMsg
+		}
 	}
 	return proto.Marshal(pmsg)
 }
 
-func (p protoEncoding) Unmarshal(buf []byte, msg drpc.Message) error {
+func (p protoEncoding) Unmarshal(buf []byte, msg drpc.Message) (err error) {
+	var pms ProtoMessageSettable
 	pmsg, ok := msg.(proto.Message)
 	if !ok {
-		return errNotAProtoMsg
+		if pms, ok = msg.(ProtoMessageSettable); ok {
+			pmsg, err = pms.ProtoMessage()
+			if err != nil {
+				return err
+			}
+		} else {
+			return errNotAProtoMsg
+		}
 	}
-	return proto.Unmarshal(buf, pmsg)
+	err = proto.Unmarshal(buf, pmsg)
+	if err != nil {
+		return err
+	}
+	if pms != nil {
+		err = pms.SetProtoMessage(pmsg)
+	}
+	return
 }
diff --git a/net/streampool/stream.go b/net/streampool/stream.go
index 28f60d76..8aae8161 100644
--- a/net/streampool/stream.go
+++ b/net/streampool/stream.go
@@ -9,6 +9,7 @@ import (
 	"storj.io/drpc"
 
 	"github.com/anyproto/any-sync/app/logger"
+	"github.com/anyproto/any-sync/util/multiqueue"
 )
 
 type stream struct {
@@ -19,7 +20,7 @@ type stream struct {
 	streamId uint32
 	closed   atomic.Bool
 	l        logger.CtxLogger
-	queue    *mb.MB[drpc.Message]
+	queue    *multiqueue.Queue[drpc.Message]
 	stats    streamStat
 	tags     []string
 }
diff --git a/net/streampool/streampool.go b/net/streampool/streampool.go
index 14be0b38..4cae48e0 100644
--- a/net/streampool/streampool.go
+++ b/net/streampool/streampool.go
@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"sync"
 
-	"github.com/cheggaaa/mb/v3"
 	"go.uber.org/zap"
 	"golang.org/x/exp/slices"
 	"golang.org/x/net/context"
@@ -13,6 +12,7 @@ import (
 	"github.com/anyproto/any-sync/app/debugstat"
 	"github.com/anyproto/any-sync/net"
 	"github.com/anyproto/any-sync/net/peer"
+	"github.com/anyproto/any-sync/util/multiqueue"
 )
 
 // StreamHandler handles incoming messages from streams
@@ -23,6 +23,8 @@ type StreamHandler interface {
 	HandleMessage(ctx context.Context, peerId string, msg drpc.Message) (err error)
 	// NewReadMessage creates new empty message for unmarshalling into it
 	NewReadMessage() drpc.Message
+	// GetQueueProvider returns queue provider for outgoing messages
+	GetQueueProvider() multiqueue.QueueProvider[drpc.Message]
 }
 
 // PeerGetter should dial or return cached peers
@@ -154,10 +156,6 @@ func (s *streamPool) addStream(drpcStream drpc.Stream, tags ...string) (*stream,
 	defer s.mu.Unlock()
 	s.lastStreamId++
 	streamId := s.lastStreamId
-	queueSize := s.writeQueueSize
-	if queueSize <= 0 {
-		queueSize = 100
-	}
 	st := &stream{
 		peerId:   peerId,
 		peerCtx:  ctx,
@@ -168,7 +166,7 @@ func (s *streamPool) addStream(drpcStream drpc.Stream, tags ...string) (*stream,
 		tags:     tags,
 		stats:    newStreamStat(peerId),
 	}
-	st.queue = mb.New[drpc.Message](s.writeQueueSize)
+	st.queue = s.handler.GetQueueProvider().GetQueue(peerId)
 	s.streams[streamId] = st
 	s.streamIdsByPeer[peerId] = append(s.streamIdsByPeer[peerId], streamId)
 	for _, tag := range tags {
diff --git a/util/multiqueue/multiqueue.go b/util/multiqueue/multiqueue.go
index ee1cce81..90974f66 100644
--- a/util/multiqueue/multiqueue.go
+++ b/util/multiqueue/multiqueue.go
@@ -3,8 +3,9 @@ package multiqueue
 import (
 	"context"
 	"errors"
-	"github.com/cheggaaa/mb/v3"
 	"sync"
+
+	"github.com/cheggaaa/mb/v3"
 )
 
 var (
@@ -25,6 +26,7 @@ type HandleFunc[T any] func(msg T)
 type MultiQueue[T any] interface {
 	Add(ctx context.Context, threadId string, msg T) (err error)
 	CloseThread(threadId string) (err error)
+	ThreadIds() []string
 	Close() (err error)
 }
 
@@ -36,6 +38,16 @@ type multiQueue[T any] struct {
 	closed       bool
 }
 
+func (m *multiQueue[T]) ThreadIds() []string {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	ids := make([]string, 0, len(m.threads))
+	for id := range m.threads {
+		ids = append(ids, id)
+	}
+	return ids
+}
+
 func (m *multiQueue[T]) Add(ctx context.Context, threadId string, msg T) (err error) {
 	m.mu.Lock()
 	if m.closed {
diff --git a/util/multiqueue/queue.go b/util/multiqueue/queue.go
new file mode 100644
index 00000000..96c50816
--- /dev/null
+++ b/util/multiqueue/queue.go
@@ -0,0 +1,35 @@
+package multiqueue
+
+import (
+	"context"
+
+	"github.com/cheggaaa/mb/v3"
+)
+
+type QueueHandler[T any] func(id string, msg T, q *mb.MB[T]) error
+
+type Queue[T any] struct {
+	id      string
+	q       *mb.MB[T]
+	handler QueueHandler[T]
+}
+
+func NewQueue[T any](id string, size int, h QueueHandler[T]) *Queue[T] {
+	return &Queue[T]{
+		id:      id,
+		q:       mb.New[T](size),
+		handler: h,
+	}
+}
+
+func (q *Queue[T]) TryAdd(msg T) error {
+	return q.handler(q.id, msg, q.q)
+}
+
+func (q *Queue[T]) WaitOne(ctx context.Context) (T, error) {
+	return q.q.WaitOne(ctx)
+}
+
+func (q *Queue[T]) Close() error {
+	return q.q.Close()
+}
diff --git a/util/multiqueue/queueprovider.go b/util/multiqueue/queueprovider.go
new file mode 100644
index 00000000..e16c24fc
--- /dev/null
+++ b/util/multiqueue/queueprovider.go
@@ -0,0 +1,47 @@
+package multiqueue
+
+import (
+	"sync"
+)
+
+type QueueProvider[T any] interface {
+	GetQueue(id string) *Queue[T]
+	RemoveQueue(id string) error
+}
+
+type queueProvider[T any] struct {
+	queues  map[string]*Queue[T]
+	mx      sync.Mutex
+	size    int
+	handler QueueHandler[T]
+}
+
+func NewQueueProvider[T any](size int, handler QueueHandler[T]) QueueProvider[T] {
+	return &queueProvider[T]{
+		queues:  make(map[string]*Queue[T]),
+		size:    size,
+		handler: handler,
+	}
+}
+
+func (p *queueProvider[T]) GetQueue(id string) *Queue[T] {
+	p.mx.Lock()
+	defer p.mx.Unlock()
+	q, ok := p.queues[id]
+	if !ok {
+		q = NewQueue(id, p.size, p.handler)
+		p.queues[id] = q
+	}
+	return q
+}
+
+func (p *queueProvider[T]) RemoveQueue(id string) error {
+	p.mx.Lock()
+	defer p.mx.Unlock()
+	q, ok := p.queues[id]
+	if !ok {
+		return nil
+	}
+	delete(p.queues, id)
+	return q.Close()
+}