diff --git a/message/inbound_msg_builder.go b/message/inbound_msg_builder.go
index 1cc1edcd8670..c52e8e0afc47 100644
--- a/message/inbound_msg_builder.go
+++ b/message/inbound_msg_builder.go
@@ -243,22 +243,18 @@ func InboundPullQuery(
 func InboundChits(
 	chainID ids.ID,
 	requestID uint32,
-	preferredContainerIDs []ids.ID,
-	acceptedContainerIDs []ids.ID,
+	preferredID ids.ID,
+	acceptedID ids.ID,
 	nodeID ids.NodeID,
 ) InboundMessage {
-	preferredContainerIDBytes := make([][]byte, len(preferredContainerIDs))
-	encodeIDs(preferredContainerIDs, preferredContainerIDBytes)
-	acceptedContainerIDBytes := make([][]byte, len(acceptedContainerIDs))
-	encodeIDs(acceptedContainerIDs, acceptedContainerIDBytes)
 	return &inboundMessage{
 		nodeID: nodeID,
 		op:     ChitsOp,
 		message: &p2p.Chits{
-			ChainId:               chainID[:],
-			RequestId:             requestID,
-			PreferredContainerIds: preferredContainerIDBytes,
-			AcceptedContainerIds:  acceptedContainerIDBytes,
+			ChainId:     chainID[:],
+			RequestId:   requestID,
+			PreferredId: preferredID[:],
+			AcceptedId:  acceptedID[:],
 		},
 		expiration: mockable.MaxTime,
 	}
diff --git a/message/inbound_msg_builder_test.go b/message/inbound_msg_builder_test.go
index 068ce857f901..951693f3e80b 100644
--- a/message/inbound_msg_builder_test.go
+++ b/message/inbound_msg_builder_test.go
@@ -327,8 +327,8 @@ func TestInboundMsgBuilder(t *testing.T) {
 			msg := InboundChits(
 				chainID,
 				requestID,
-				containerIDs,
-				acceptedContainerIDs,
+				containerIDs[0],
+				acceptedContainerIDs[0],
 				nodeID,
 			)
 
@@ -339,18 +339,8 @@ func TestInboundMsgBuilder(t *testing.T) {
 			innerMsg := msg.Message().(*p2p.Chits)
 			require.Equal(chainID[:], innerMsg.ChainId)
 			require.Equal(requestID, innerMsg.RequestId)
-			containerIDsBytes := make([][]byte, len(containerIDs))
-			for i, id := range containerIDs {
-				id := id
-				containerIDsBytes[i] = id[:]
-			}
-			require.Equal(containerIDsBytes, innerMsg.PreferredContainerIds)
-			acceptedContainerIDsBytes := make([][]byte, len(acceptedContainerIDs))
-			for i, id := range acceptedContainerIDs {
-				id := id
-				acceptedContainerIDsBytes[i] = id[:]
-			}
-			require.Equal(acceptedContainerIDsBytes, innerMsg.AcceptedContainerIds)
+			require.Equal(containerIDs[0][:], innerMsg.PreferredId)
+			require.Equal(acceptedContainerIDs[0][:], innerMsg.AcceptedId)
 		},
 	)
 
diff --git a/message/messages_test.go b/message/messages_test.go
index d0beaa6fc67b..33ee2ca35428 100644
--- a/message/messages_test.go
+++ b/message/messages_test.go
@@ -672,9 +672,9 @@ func TestMessage(t *testing.T) {
 			msg: &p2p.Message{
 				Message: &p2p.Message_Chits{
 					Chits: &p2p.Chits{
-						ChainId:               testID[:],
-						RequestId:             1,
-						PreferredContainerIds: [][]byte{testID[:], testID[:]},
+						ChainId:     testID[:],
+						RequestId:   1,
+						PreferredId: testID[:],
 					},
 				},
 			},
diff --git a/message/mock_outbound_message_builder.go b/message/mock_outbound_message_builder.go
index 5d34b6ba3bb9..d8b1b46fa912 100644
--- a/message/mock_outbound_message_builder.go
+++ b/message/mock_outbound_message_builder.go
@@ -146,7 +146,7 @@ func (mr *MockOutboundMsgBuilderMockRecorder) AppResponse(arg0, arg1, arg2 inter
 }
 
 // Chits mocks base method.
-func (m *MockOutboundMsgBuilder) Chits(arg0 ids.ID, arg1 uint32, arg2, arg3 []ids.ID) (OutboundMessage, error) {
+func (m *MockOutboundMsgBuilder) Chits(arg0 ids.ID, arg1 uint32, arg2, arg3 ids.ID) (OutboundMessage, error) {
 	m.ctrl.T.Helper()
 	ret := m.ctrl.Call(m, "Chits", arg0, arg1, arg2, arg3)
 	ret0, _ := ret[0].(OutboundMessage)
diff --git a/message/outbound_msg_builder.go b/message/outbound_msg_builder.go
index 330df8f794ce..828bda0d5b40 100644
--- a/message/outbound_msg_builder.go
+++ b/message/outbound_msg_builder.go
@@ -147,8 +147,8 @@ type OutboundMsgBuilder interface {
 	Chits(
 		chainID ids.ID,
 		requestID uint32,
-		preferredContainerIDs []ids.ID,
-		acceptedContainerIDs []ids.ID,
+		preferredID ids.ID,
+		acceptedID ids.ID,
 	) (OutboundMessage, error)
 
 	AppRequest(
@@ -608,21 +608,17 @@ func (b *outMsgBuilder) PullQuery(
 func (b *outMsgBuilder) Chits(
 	chainID ids.ID,
 	requestID uint32,
-	preferredContainerIDs []ids.ID,
-	acceptedContainerIDs []ids.ID,
+	preferredID ids.ID,
+	acceptedID ids.ID,
 ) (OutboundMessage, error) {
-	preferredContainerIDBytes := make([][]byte, len(preferredContainerIDs))
-	encodeIDs(preferredContainerIDs, preferredContainerIDBytes)
-	acceptedContainerIDBytes := make([][]byte, len(acceptedContainerIDs))
-	encodeIDs(acceptedContainerIDs, acceptedContainerIDBytes)
 	return b.builder.createOutbound(
 		&p2p.Message{
 			Message: &p2p.Message_Chits{
 				Chits: &p2p.Chits{
-					ChainId:               chainID[:],
-					RequestId:             requestID,
-					PreferredContainerIds: preferredContainerIDBytes,
-					AcceptedContainerIds:  acceptedContainerIDBytes,
+					ChainId:     chainID[:],
+					RequestId:   requestID,
+					PreferredId: preferredID[:],
+					AcceptedId:  acceptedID[:],
 				},
 			},
 		},
diff --git a/proto/p2p/p2p.proto b/proto/p2p/p2p.proto
index 86d0505330b5..f5726512f262 100644
--- a/proto/p2p/p2p.proto
+++ b/proto/p2p/p2p.proto
@@ -318,23 +318,22 @@ message PullQuery {
   EngineType engine_type = 5;
 }
 
-// Message that contains the votes/preferences of the local node,
-// in response to "push_query" or "pull_query" (e.g., preferred frontier).
+// Message that contains the votes/preferences of the node. It is sent in
+// response to a "push_query" or "pull_query" request.
 //
-// On receiving "chits", the engine issues those preferred containers of vertices/blocks
-// to the consensus. If the received container is not found, it responds back with
-// "get" message to fetch the missing container from the remote peer.
+// Upon receiving "chits", the engine will attempt to issue the preferred block
+// into consensus. If the referenced block is not locally available, the engine
+// will respond with a "get" message to fetch the missing block from the remote
+// peer.
 message Chits {
   reserved 5; // Until Cortina upgrade is activated
 
   bytes chain_id = 1;
   uint32 request_id = 2;
-  // Represents the current preferred frontier.
-  // TODO: Remove `repeated` once all chains are running Snowman.
-  repeated bytes preferred_container_ids = 3;
-  // Represents the current accepted frontier.
-  // TODO: Remove `repeated` once all chains are running Snowman.
-  repeated bytes accepted_container_ids = 4;
+  // Represents the current preferred block.
+  bytes preferred_id = 3;
+  // Represents the last accepted block.
+  bytes accepted_id = 4;
 }
 
 message AppRequest {
diff --git a/proto/pb/p2p/p2p.pb.go b/proto/pb/p2p/p2p.pb.go
index ac74a80f3a3d..31cdbf09b1dd 100644
--- a/proto/pb/p2p/p2p.pb.go
+++ b/proto/pb/p2p/p2p.pb.go
@@ -2077,12 +2077,13 @@ func (x *PullQuery) GetEngineType() EngineType {
 	return EngineType_ENGINE_TYPE_UNSPECIFIED
 }
 
-// Message that contains the votes/preferences of the local node,
-// in response to "push_query" or "pull_query" (e.g., preferred frontier).
+// Message that contains the votes/preferences of the node. It is sent in
+// response to a "push_query" or "pull_query" request.
 //
-// On receiving "chits", the engine issues those preferred containers of vertices/blocks
-// to the consensus. If the received container is not found, it responds back with
-// "get" message to fetch the missing container from the remote peer.
+// Upon receiving "chits", the engine will attempt to issue the preferred block
+// into consensus. If the referenced block is not locally available, the engine
+// will respond with a "get" message to fetch the missing block from the remote
+// peer.
 type Chits struct {
 	state         protoimpl.MessageState
 	sizeCache     protoimpl.SizeCache
@@ -2090,12 +2091,10 @@ type Chits struct {
 
 	ChainId   []byte `protobuf:"bytes,1,opt,name=chain_id,json=chainId,proto3" json:"chain_id,omitempty"`
 	RequestId uint32 `protobuf:"varint,2,opt,name=request_id,json=requestId,proto3" json:"request_id,omitempty"`
-	// Represents the current preferred frontier.
-	// TODO: Remove `repeated` once all chains are running Snowman.
-	PreferredContainerIds [][]byte `protobuf:"bytes,3,rep,name=preferred_container_ids,json=preferredContainerIds,proto3" json:"preferred_container_ids,omitempty"`
-	// Represents the current accepted frontier.
-	// TODO: Remove `repeated` once all chains are running Snowman.
-	AcceptedContainerIds [][]byte `protobuf:"bytes,4,rep,name=accepted_container_ids,json=acceptedContainerIds,proto3" json:"accepted_container_ids,omitempty"`
+	// Represents the current preferred block.
+	PreferredId []byte `protobuf:"bytes,3,opt,name=preferred_id,json=preferredId,proto3" json:"preferred_id,omitempty"`
+	// Represents the last accepted block.
+	AcceptedId []byte `protobuf:"bytes,4,opt,name=accepted_id,json=acceptedId,proto3" json:"accepted_id,omitempty"`
 }
 
 func (x *Chits) Reset() {
@@ -2144,16 +2143,16 @@ func (x *Chits) GetRequestId() uint32 {
 	return 0
 }
 
-func (x *Chits) GetPreferredContainerIds() [][]byte {
+func (x *Chits) GetPreferredId() []byte {
 	if x != nil {
-		return x.PreferredContainerIds
+		return x.PreferredId
 	}
 	return nil
 }
 
-func (x *Chits) GetAcceptedContainerIds() [][]byte {
+func (x *Chits) GetAcceptedId() []byte {
 	if x != nil {
-		return x.AcceptedContainerIds
+		return x.AcceptedId
 	}
 	return nil
 }
@@ -2620,47 +2619,44 @@ var file_p2p_p2p_proto_rawDesc = []byte{
 	0x6f, 0x6e, 0x74, 0x61, 0x69, 0x6e, 0x65, 0x72, 0x49, 0x64, 0x12, 0x30, 0x0a, 0x0b, 0x65, 0x6e,
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+	0x73, 0x22, 0x43, 0x0a, 0x09, 0x41, 0x70, 0x70, 0x47, 0x6f, 0x73, 0x73, 0x69, 0x70, 0x12, 0x19,
+	0x0a, 0x08, 0x63, 0x68, 0x61, 0x69, 0x6e, 0x5f, 0x69, 0x64, 0x18, 0x01, 0x20, 0x01, 0x28, 0x0c,
+	0x52, 0x07, 0x63, 0x68, 0x61, 0x69, 0x6e, 0x49, 0x64, 0x12, 0x1b, 0x0a, 0x09, 0x61, 0x70, 0x70,
+	0x5f, 0x62, 0x79, 0x74, 0x65, 0x73, 0x18, 0x02, 0x20, 0x01, 0x28, 0x0c, 0x52, 0x08, 0x61, 0x70,
+	0x70, 0x42, 0x79, 0x74, 0x65, 0x73, 0x2a, 0x5d, 0x0a, 0x0a, 0x45, 0x6e, 0x67, 0x69, 0x6e, 0x65,
+	0x54, 0x79, 0x70, 0x65, 0x12, 0x1b, 0x0a, 0x17, 0x45, 0x4e, 0x47, 0x49, 0x4e, 0x45, 0x5f, 0x54,
+	0x59, 0x50, 0x45, 0x5f, 0x55, 0x4e, 0x53, 0x50, 0x45, 0x43, 0x49, 0x46, 0x49, 0x45, 0x44, 0x10,
+	0x00, 0x12, 0x19, 0x0a, 0x15, 0x45, 0x4e, 0x47, 0x49, 0x4e, 0x45, 0x5f, 0x54, 0x59, 0x50, 0x45,
+	0x5f, 0x41, 0x56, 0x41, 0x4c, 0x41, 0x4e, 0x43, 0x48, 0x45, 0x10, 0x01, 0x12, 0x17, 0x0a, 0x13,
+	0x45, 0x4e, 0x47, 0x49, 0x4e, 0x45, 0x5f, 0x54, 0x59, 0x50, 0x45, 0x5f, 0x53, 0x4e, 0x4f, 0x57,
+	0x4d, 0x41, 0x4e, 0x10, 0x02, 0x42, 0x2e, 0x5a, 0x2c, 0x67, 0x69, 0x74, 0x68, 0x75, 0x62, 0x2e,
+	0x63, 0x6f, 0x6d, 0x2f, 0x61, 0x76, 0x61, 0x2d, 0x6c, 0x61, 0x62, 0x73, 0x2f, 0x61, 0x76, 0x61,
+	0x6c, 0x61, 0x6e, 0x63, 0x68, 0x65, 0x67, 0x6f, 0x2f, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x2f, 0x70,
+	0x62, 0x2f, 0x70, 0x32, 0x70, 0x62, 0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x33,
 }
 
 var (
diff --git a/snow/engine/common/engine.go b/snow/engine/common/engine.go
index 142351b2ea6b..6466a66874b8 100644
--- a/snow/engine/common/engine.go
+++ b/snow/engine/common/engine.go
@@ -390,8 +390,8 @@ type ChitsHandler interface {
 		ctx context.Context,
 		validatorID ids.NodeID,
 		requestID uint32,
-		preferredContainerIDs []ids.ID,
-		acceptedContainerIDs []ids.ID,
+		preferredID ids.ID,
+		acceptedID ids.ID,
 	) error
 
 	// Notify this engine that a query it issued has failed.
diff --git a/snow/engine/common/mock_sender.go b/snow/engine/common/mock_sender.go
index c599077dd881..6eccda2e6232 100644
--- a/snow/engine/common/mock_sender.go
+++ b/snow/engine/common/mock_sender.go
@@ -159,7 +159,7 @@ func (mr *MockSenderMockRecorder) SendAppResponse(arg0, arg1, arg2, arg3 interfa
 }
 
 // SendChits mocks base method.
-func (m *MockSender) SendChits(arg0 context.Context, arg1 ids.NodeID, arg2 uint32, arg3, arg4 []ids.ID) {
+func (m *MockSender) SendChits(arg0 context.Context, arg1 ids.NodeID, arg2 uint32, arg3, arg4 ids.ID) {
 	m.ctrl.T.Helper()
 	m.ctrl.Call(m, "SendChits", arg0, arg1, arg2, arg3, arg4)
 }
diff --git a/snow/engine/common/no_ops_handlers.go b/snow/engine/common/no_ops_handlers.go
index de3c98175484..06c30a8bb097 100644
--- a/snow/engine/common/no_ops_handlers.go
+++ b/snow/engine/common/no_ops_handlers.go
@@ -242,12 +242,14 @@ func NewNoOpChitsHandler(log logging.Logger) ChitsHandler {
 	return &noOpChitsHandler{log: log}
 }
 
-func (nop *noOpChitsHandler) Chits(_ context.Context, nodeID ids.NodeID, requestID uint32, _, _ []ids.ID) error {
+func (nop *noOpChitsHandler) Chits(_ context.Context, nodeID ids.NodeID, requestID uint32, preferredID, acceptedID ids.ID) error {
 	nop.log.Debug("dropping request",
 		zap.String("reason", "unhandled by this gear"),
 		zap.Stringer("messageOp", message.ChitsOp),
 		zap.Stringer("nodeID", nodeID),
 		zap.Uint32("requestID", requestID),
+		zap.Stringer("preferredID", preferredID),
+		zap.Stringer("acceptedID", acceptedID),
 	)
 	return nil
 }
diff --git a/snow/engine/common/sender.go b/snow/engine/common/sender.go
index 1c657daa3555..a8d9f88390c8 100644
--- a/snow/engine/common/sender.go
+++ b/snow/engine/common/sender.go
@@ -117,7 +117,7 @@ type QuerySender interface {
 	SendPullQuery(ctx context.Context, nodeIDs set.Set[ids.NodeID], requestID uint32, containerID ids.ID)
 
 	// Send chits to the specified node
-	SendChits(ctx context.Context, nodeID ids.NodeID, requestID uint32, votes []ids.ID, accepted []ids.ID)
+	SendChits(ctx context.Context, nodeID ids.NodeID, requestID uint32, preferredID ids.ID, acceptedID ids.ID)
 }
 
 // Gossiper defines how a consensus engine gossips a container on the accepted
diff --git a/snow/engine/common/test_engine.go b/snow/engine/common/test_engine.go
index 6645efad33e0..ade1d6e00455 100644
--- a/snow/engine/common/test_engine.go
+++ b/snow/engine/common/test_engine.go
@@ -115,7 +115,7 @@ type EngineTest struct {
 	PutF, PushQueryF                           func(ctx context.Context, nodeID ids.NodeID, requestID uint32, container []byte) error
 	AncestorsF                                 func(ctx context.Context, nodeID ids.NodeID, requestID uint32, containers [][]byte) error
 	AcceptedFrontierF, GetAcceptedF, AcceptedF func(ctx context.Context, nodeID ids.NodeID, requestID uint32, preferredIDs []ids.ID) error
-	ChitsF                                     func(ctx context.Context, nodeID ids.NodeID, requestID uint32, preferredIDs []ids.ID, acceptedIDs []ids.ID) error
+	ChitsF                                     func(ctx context.Context, nodeID ids.NodeID, requestID uint32, preferredID ids.ID, acceptedID ids.ID) error
 	GetStateSummaryFrontierF, GetStateSummaryFrontierFailedF, GetAcceptedStateSummaryFailedF,
 	GetAcceptedFrontierF, GetFailedF, GetAncestorsFailedF,
 	QueryFailedF, GetAcceptedFrontierFailedF, GetAcceptedFailedF func(ctx context.Context, nodeID ids.NodeID, requestID uint32) error
@@ -631,9 +631,9 @@ func (e *EngineTest) AppGossip(ctx context.Context, nodeID ids.NodeID, msg []byt
 	return errAppGossip
 }
 
-func (e *EngineTest) Chits(ctx context.Context, nodeID ids.NodeID, requestID uint32, preferredIDs []ids.ID, acceptedIDs []ids.ID) error {
+func (e *EngineTest) Chits(ctx context.Context, nodeID ids.NodeID, requestID uint32, preferredID ids.ID, acceptedID ids.ID) error {
 	if e.ChitsF != nil {
-		return e.ChitsF(ctx, nodeID, requestID, preferredIDs, acceptedIDs)
+		return e.ChitsF(ctx, nodeID, requestID, preferredID, acceptedID)
 	}
 	if !e.CantChits {
 		return nil
diff --git a/snow/engine/common/test_sender.go b/snow/engine/common/test_sender.go
index 0a32dcc00ea2..e1d797cf13a9 100644
--- a/snow/engine/common/test_sender.go
+++ b/snow/engine/common/test_sender.go
@@ -53,7 +53,7 @@ type SenderTest struct {
 	SendAncestorsF               func(context.Context, ids.NodeID, uint32, [][]byte)
 	SendPushQueryF               func(context.Context, set.Set[ids.NodeID], uint32, []byte)
 	SendPullQueryF               func(context.Context, set.Set[ids.NodeID], uint32, ids.ID)
-	SendChitsF                   func(context.Context, ids.NodeID, uint32, []ids.ID, []ids.ID)
+	SendChitsF                   func(context.Context, ids.NodeID, uint32, ids.ID, ids.ID)
 	SendGossipF                  func(context.Context, []byte)
 	SendAppRequestF              func(context.Context, set.Set[ids.NodeID], uint32, []byte) error
 	SendAppResponseF             func(context.Context, ids.NodeID, uint32, []byte) error
@@ -263,9 +263,9 @@ func (s *SenderTest) SendPullQuery(ctx context.Context, vdrs set.Set[ids.NodeID]
 // SendChits calls SendChitsF if it was initialized. If it wasn't initialized
 // and this function shouldn't be called and testing was initialized, then
 // testing will fail.
-func (s *SenderTest) SendChits(ctx context.Context, vdr ids.NodeID, requestID uint32, votes []ids.ID, accepted []ids.ID) {
+func (s *SenderTest) SendChits(ctx context.Context, vdr ids.NodeID, requestID uint32, preferredID ids.ID, acceptedID ids.ID) {
 	if s.SendChitsF != nil {
-		s.SendChitsF(ctx, vdr, requestID, votes, accepted)
+		s.SendChitsF(ctx, vdr, requestID, preferredID, acceptedID)
 	} else if s.CantSendChits && s.T != nil {
 		s.T.Fatalf("Unexpectedly called SendChits")
 	}
diff --git a/snow/engine/common/traced_engine.go b/snow/engine/common/traced_engine.go
index f2e723a4d176..73bb02efc5cb 100644
--- a/snow/engine/common/traced_engine.go
+++ b/snow/engine/common/traced_engine.go
@@ -243,16 +243,16 @@ func (e *tracedEngine) PushQuery(ctx context.Context, nodeID ids.NodeID, request
 	return e.engine.PushQuery(ctx, nodeID, requestID, container)
 }
 
-func (e *tracedEngine) Chits(ctx context.Context, nodeID ids.NodeID, requestID uint32, preferredIDs []ids.ID, acceptedIDs []ids.ID) error {
+func (e *tracedEngine) Chits(ctx context.Context, nodeID ids.NodeID, requestID uint32, preferredID ids.ID, acceptedID ids.ID) error {
 	ctx, span := e.tracer.Start(ctx, "tracedEngine.Chits", oteltrace.WithAttributes(
 		attribute.Stringer("nodeID", nodeID),
 		attribute.Int64("requestID", int64(requestID)),
-		attribute.Int("numPreferredIDs", len(preferredIDs)),
-		attribute.Int("numAcceptedIDs", len(acceptedIDs)),
+		attribute.Stringer("preferredID", preferredID),
+		attribute.Stringer("acceptedID", acceptedID),
 	))
 	defer span.End()
 
-	return e.engine.Chits(ctx, nodeID, requestID, preferredIDs, acceptedIDs)
+	return e.engine.Chits(ctx, nodeID, requestID, preferredID, acceptedID)
 }
 
 func (e *tracedEngine) QueryFailed(ctx context.Context, nodeID ids.NodeID, requestID uint32) error {
diff --git a/snow/engine/common/tracker/accepted.go b/snow/engine/common/tracker/accepted.go
index 4b3f0f1ac783..0be64bc9035e 100644
--- a/snow/engine/common/tracker/accepted.go
+++ b/snow/engine/common/tracker/accepted.go
@@ -9,6 +9,7 @@ import (
 	"github.com/ava-labs/avalanchego/ids"
 	"github.com/ava-labs/avalanchego/snow/validators"
 	"github.com/ava-labs/avalanchego/utils/crypto/bls"
+	"github.com/ava-labs/avalanchego/utils/set"
 )
 
 var _ Accepted = (*accepted)(nil)
@@ -16,24 +17,23 @@ var _ Accepted = (*accepted)(nil)
 type Accepted interface {
 	validators.SetCallbackListener
 
-	// SetAcceptedFrontier updates the latest frontier for [nodeID] to
-	// [frontier]. If [nodeID] is not currently a validator, this is a noop.
-	SetAcceptedFrontier(nodeID ids.NodeID, frontier []ids.ID)
-	// AcceptedFrontier returns the latest known accepted frontier of [nodeID].
-	// If [nodeID]'s last accepted frontier is unknown, an empty slice will be
-	// returned.
-	AcceptedFrontier(nodeID ids.NodeID) []ids.ID
+	// SetLastAccepted updates the latest accepted block for [nodeID] to
+	// [blockID]. If [nodeID] is not currently a validator, this is a noop.
+	SetLastAccepted(nodeID ids.NodeID, blockID ids.ID)
+	// LastAccepted returns the latest known accepted block of [nodeID]. If
+	// [nodeID]'s last accepted block was never unknown, false will be returned.
+	LastAccepted(nodeID ids.NodeID) (ids.ID, bool)
 }
 
 type accepted struct {
-	lock sync.RWMutex
-	// frontier contains an entry for all current validators
-	frontier map[ids.NodeID][]ids.ID
+	lock       sync.RWMutex
+	validators set.Set[ids.NodeID]
+	frontier   map[ids.NodeID]ids.ID
 }
 
 func NewAccepted() Accepted {
 	return &accepted{
-		frontier: make(map[ids.NodeID][]ids.ID),
+		frontier: make(map[ids.NodeID]ids.ID),
 	}
 }
 
@@ -41,30 +41,32 @@ func (a *accepted) OnValidatorAdded(nodeID ids.NodeID, _ *bls.PublicKey, _ ids.I
 	a.lock.Lock()
 	defer a.lock.Unlock()
 
-	a.frontier[nodeID] = nil
+	a.validators.Add(nodeID)
 }
 
 func (a *accepted) OnValidatorRemoved(nodeID ids.NodeID, _ uint64) {
 	a.lock.Lock()
 	defer a.lock.Unlock()
 
+	a.validators.Remove(nodeID)
 	delete(a.frontier, nodeID)
 }
 
 func (*accepted) OnValidatorWeightChanged(_ ids.NodeID, _, _ uint64) {}
 
-func (a *accepted) SetAcceptedFrontier(nodeID ids.NodeID, frontier []ids.ID) {
+func (a *accepted) SetLastAccepted(nodeID ids.NodeID, frontier ids.ID) {
 	a.lock.Lock()
 	defer a.lock.Unlock()
 
-	if _, ok := a.frontier[nodeID]; ok {
+	if a.validators.Contains(nodeID) {
 		a.frontier[nodeID] = frontier
 	}
 }
 
-func (a *accepted) AcceptedFrontier(nodeID ids.NodeID) []ids.ID {
+func (a *accepted) LastAccepted(nodeID ids.NodeID) (ids.ID, bool) {
 	a.lock.RLock()
 	defer a.lock.RUnlock()
 
-	return a.frontier[nodeID]
+	acceptedID, ok := a.frontier[nodeID]
+	return acceptedID, ok
 }
diff --git a/snow/engine/common/tracker/accepted_test.go b/snow/engine/common/tracker/accepted_test.go
index dbd5faf89808..7bb617d789f9 100644
--- a/snow/engine/common/tracker/accepted_test.go
+++ b/snow/engine/common/tracker/accepted_test.go
@@ -15,27 +15,35 @@ func TestAccepted(t *testing.T) {
 	require := require.New(t)
 
 	nodeID := ids.GenerateTestNodeID()
-	frontier0 := []ids.ID{ids.GenerateTestID()}
-	frontier1 := []ids.ID{ids.GenerateTestID()}
+	blkID0 := ids.GenerateTestID()
+	blkID1 := ids.GenerateTestID()
 
 	a := NewAccepted()
 
-	require.Empty(a.AcceptedFrontier(nodeID))
+	_, ok := a.LastAccepted(nodeID)
+	require.False(ok)
 
-	a.SetAcceptedFrontier(nodeID, frontier0)
-	require.Empty(a.AcceptedFrontier(nodeID))
+	a.SetLastAccepted(nodeID, blkID0)
+	_, ok = a.LastAccepted(nodeID)
+	require.False(ok)
 
 	a.OnValidatorAdded(nodeID, nil, ids.GenerateTestID(), 1)
 
-	require.Empty(a.AcceptedFrontier(nodeID))
+	_, ok = a.LastAccepted(nodeID)
+	require.False(ok)
 
-	a.SetAcceptedFrontier(nodeID, frontier0)
-	require.Equal(frontier0, a.AcceptedFrontier(nodeID))
+	a.SetLastAccepted(nodeID, blkID0)
+	blkID, ok := a.LastAccepted(nodeID)
+	require.True(ok)
+	require.Equal(blkID0, blkID)
 
-	a.SetAcceptedFrontier(nodeID, frontier1)
-	require.Equal(frontier1, a.AcceptedFrontier(nodeID))
+	a.SetLastAccepted(nodeID, blkID1)
+	blkID, ok = a.LastAccepted(nodeID)
+	require.True(ok)
+	require.Equal(blkID1, blkID)
 
 	a.OnValidatorRemoved(nodeID, 1)
 
-	require.Empty(a.AcceptedFrontier(nodeID))
+	_, ok = a.LastAccepted(nodeID)
+	require.False(ok)
 }
diff --git a/snow/engine/snowman/transitive.go b/snow/engine/snowman/transitive.go
index 1cdfce43df95..5daf34ba76fd 100644
--- a/snow/engine/snowman/transitive.go
+++ b/snow/engine/snowman/transitive.go
@@ -249,23 +249,8 @@ func (t *Transitive) PushQuery(ctx context.Context, nodeID ids.NodeID, requestID
 	return t.buildBlocks(ctx)
 }
 
-func (t *Transitive) Chits(ctx context.Context, nodeID ids.NodeID, requestID uint32, votes []ids.ID, accepted []ids.ID) error {
-	t.acceptedFrontiers.SetAcceptedFrontier(nodeID, accepted)
-
-	// Since this is a linear chain, there should only be one ID in the vote set
-	if len(votes) != 1 {
-		t.Ctx.Log.Debug("failing Chits",
-			zap.String("reason", "expected only 1 vote"),
-			zap.Int("numVotes", len(votes)),
-			zap.Stringer("nodeID", nodeID),
-			zap.Uint32("requestID", requestID),
-		)
-		// because QueryFailed doesn't utilize the assumption that we actually
-		// sent a Query message, we can safely call QueryFailed here to
-		// potentially abandon the request.
-		return t.QueryFailed(ctx, nodeID, requestID)
-	}
-	blkID := votes[0]
+func (t *Transitive) Chits(ctx context.Context, nodeID ids.NodeID, requestID uint32, blkID ids.ID, acceptedID ids.ID) error {
+	t.acceptedFrontiers.SetLastAccepted(nodeID, acceptedID)
 
 	t.Ctx.Log.Verbo("called Chits for the block",
 		zap.Stringer("blkID", blkID),
@@ -295,10 +280,8 @@ func (t *Transitive) Chits(ctx context.Context, nodeID ids.NodeID, requestID uin
 }
 
 func (t *Transitive) QueryFailed(ctx context.Context, nodeID ids.NodeID, requestID uint32) error {
-	lastAccepted := t.acceptedFrontiers.AcceptedFrontier(nodeID)
-	if len(lastAccepted) == 1 {
-		// Chits calls QueryFailed if [votes] doesn't have length 1, so this
-		// check is required to avoid infinite mutual recursion.
+	lastAccepted, ok := t.acceptedFrontiers.LastAccepted(nodeID)
+	if ok {
 		return t.Chits(ctx, nodeID, requestID, lastAccepted, lastAccepted)
 	}
 
@@ -463,9 +446,9 @@ func (t *Transitive) GetBlock(ctx context.Context, blkID ids.ID) (snowman.Block,
 func (t *Transitive) sendChits(ctx context.Context, nodeID ids.NodeID, requestID uint32) {
 	lastAccepted := t.Consensus.LastAccepted()
 	if t.Ctx.StateSyncing.Get() {
-		t.Sender.SendChits(ctx, nodeID, requestID, []ids.ID{lastAccepted}, []ids.ID{lastAccepted})
+		t.Sender.SendChits(ctx, nodeID, requestID, lastAccepted, lastAccepted)
 	} else {
-		t.Sender.SendChits(ctx, nodeID, requestID, []ids.ID{t.Consensus.Preference()}, []ids.ID{lastAccepted})
+		t.Sender.SendChits(ctx, nodeID, requestID, t.Consensus.Preference(), lastAccepted)
 	}
 }
 
diff --git a/snow/engine/snowman/transitive_test.go b/snow/engine/snowman/transitive_test.go
index b00f8afcd49a..e43f0710145e 100644
--- a/snow/engine/snowman/transitive_test.go
+++ b/snow/engine/snowman/transitive_test.go
@@ -213,7 +213,7 @@ func TestEngineQuery(t *testing.T) {
 	}
 
 	chitted := new(bool)
-	sender.SendChitsF = func(_ context.Context, inVdr ids.NodeID, requestID uint32, prefSet []ids.ID, accepted []ids.ID) {
+	sender.SendChitsF = func(_ context.Context, inVdr ids.NodeID, requestID uint32, vote ids.ID, accepted ids.ID) {
 		if *chitted {
 			t.Fatalf("Sent multiple chits")
 		}
@@ -221,16 +221,10 @@ func TestEngineQuery(t *testing.T) {
 		if requestID != 15 {
 			t.Fatalf("Wrong request ID")
 		}
-		if len(prefSet) != 1 {
-			t.Fatal("Should only be one vote")
-		}
-		if gBlk.ID() != prefSet[0] {
+		if gBlk.ID() != vote {
 			t.Fatalf("Wrong chits block")
 		}
-		if len(accepted) != 1 {
-			t.Fatal("accepted should only have one element")
-		}
-		if gBlk.ID() != accepted[0] {
+		if gBlk.ID() != accepted {
 			t.Fatalf("Wrong accepted frontier")
 		}
 	}
@@ -343,7 +337,7 @@ func TestEngineQuery(t *testing.T) {
 			t.Fatalf("Asking for wrong block")
 		}
 	}
-	if err := te.Chits(context.Background(), vdr, *queryRequestID, []ids.ID{blk1.ID()}, nil); err != nil {
+	if err := te.Chits(context.Background(), vdr, *queryRequestID, blk1.ID(), blk1.ID()); err != nil {
 		t.Fatal(err)
 	}
 
@@ -553,11 +547,10 @@ func TestEngineMultipleQuery(t *testing.T) {
 			t.Fatalf("Asking for wrong block")
 		}
 	}
-	blkSet := []ids.ID{blk1.ID()}
-	if err := te.Chits(context.Background(), vdr0, *queryRequestID, blkSet, nil); err != nil {
+	if err := te.Chits(context.Background(), vdr0, *queryRequestID, blk1.ID(), blk1.ID()); err != nil {
 		t.Fatal(err)
 	}
-	if err := te.Chits(context.Background(), vdr1, *queryRequestID, blkSet, nil); err != nil {
+	if err := te.Chits(context.Background(), vdr1, *queryRequestID, blk1.ID(), blk1.ID()); err != nil {
 		t.Fatal(err)
 	}
 
@@ -598,8 +591,7 @@ func TestEngineMultipleQuery(t *testing.T) {
 	}
 
 	// Should be dropped because the query was already filled
-	blkSet = []ids.ID{blk0.ID()}
-	if err := te.Chits(context.Background(), vdr2, *queryRequestID, blkSet, nil); err != nil {
+	if err := te.Chits(context.Background(), vdr2, *queryRequestID, blk0.ID(), blk0.ID()); err != nil {
 		t.Fatal(err)
 	}
 
@@ -769,7 +761,7 @@ func TestEnginePushQuery(t *testing.T) {
 	}
 
 	chitted := new(bool)
-	sender.SendChitsF = func(_ context.Context, inVdr ids.NodeID, requestID uint32, votes []ids.ID, accepted []ids.ID) {
+	sender.SendChitsF = func(_ context.Context, inVdr ids.NodeID, requestID uint32, vote ids.ID, accepted ids.ID) {
 		if *chitted {
 			t.Fatalf("Sent chit multiple times")
 		}
@@ -780,16 +772,10 @@ func TestEnginePushQuery(t *testing.T) {
 		if requestID != 20 {
 			t.Fatalf("Wrong request id")
 		}
-		if len(votes) != 1 {
-			t.Fatal("votes should only have one element")
-		}
-		if gBlk.ID() != votes[0] {
+		if gBlk.ID() != vote {
 			t.Fatalf("Asking for wrong block")
 		}
-		if len(accepted) != 1 {
-			t.Fatal("accepted should only have one element")
-		}
-		if gBlk.ID() != accepted[0] {
+		if gBlk.ID() != accepted {
 			t.Fatalf("Wrong accepted frontier")
 		}
 	}
@@ -1205,7 +1191,7 @@ func TestEngineAbandonChit(t *testing.T) {
 	}
 
 	// Register a voter dependency on an unknown block.
-	require.NoError(te.Chits(context.Background(), vdr, reqID, []ids.ID{fakeBlkID}, nil))
+	require.NoError(te.Chits(context.Background(), vdr, reqID, fakeBlkID, fakeBlkID))
 	require.Len(te.blocked, 1)
 
 	sender.CantSendPullQuery = false
@@ -1260,7 +1246,7 @@ func TestEngineAbandonChitWithUnexpectedPutBlock(t *testing.T) {
 	}
 
 	// Register a voter dependency on an unknown block.
-	require.NoError(te.Chits(context.Background(), vdr, reqID, []ids.ID{fakeBlkID}, nil))
+	require.NoError(te.Chits(context.Background(), vdr, reqID, fakeBlkID, fakeBlkID))
 	require.Len(te.blocked, 1)
 
 	sender.CantSendPullQuery = false
@@ -1427,7 +1413,7 @@ func TestEngineBlockingChitResponse(t *testing.T) {
 	sender.SendPushQueryF = nil
 	sender.CantSendPushQuery = false
 
-	if err := te.Chits(context.Background(), vdr, *queryRequestID, []ids.ID{blockingBlk.ID()}, nil); err != nil {
+	if err := te.Chits(context.Background(), vdr, *queryRequestID, blockingBlk.ID(), blockingBlk.ID()); err != nil {
 		t.Fatal(err)
 	}
 
@@ -1545,7 +1531,7 @@ func TestEngineUndeclaredDependencyDeadlock(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	if err := te.Chits(context.Background(), vdr, *reqID, []ids.ID{invalidBlkID}, nil); err != nil {
+	if err := te.Chits(context.Background(), vdr, *reqID, invalidBlkID, invalidBlkID); err != nil {
 		t.Fatal(err)
 	}
 
@@ -2003,13 +1989,11 @@ func TestEngineDoubleChit(t *testing.T) {
 		panic("Should have errored")
 	}
 
-	blkSet := []ids.ID{blk.ID()}
-
 	if status := blk.Status(); status != choices.Processing {
 		t.Fatalf("Wrong status: %s ; expected: %s", status, choices.Processing)
 	}
 
-	if err := te.Chits(context.Background(), vdr0, *queryRequestID, blkSet, nil); err != nil {
+	if err := te.Chits(context.Background(), vdr0, *queryRequestID, blk.ID(), blk.ID()); err != nil {
 		t.Fatal(err)
 	}
 
@@ -2017,7 +2001,7 @@ func TestEngineDoubleChit(t *testing.T) {
 		t.Fatalf("Wrong status: %s ; expected: %s", status, choices.Processing)
 	}
 
-	if err := te.Chits(context.Background(), vdr0, *queryRequestID, blkSet, nil); err != nil {
+	if err := te.Chits(context.Background(), vdr0, *queryRequestID, blk.ID(), blk.ID()); err != nil {
 		t.Fatal(err)
 	}
 
@@ -2025,7 +2009,7 @@ func TestEngineDoubleChit(t *testing.T) {
 		t.Fatalf("Wrong status: %s ; expected: %s", status, choices.Processing)
 	}
 
-	if err := te.Chits(context.Background(), vdr1, *queryRequestID, blkSet, nil); err != nil {
+	if err := te.Chits(context.Background(), vdr1, *queryRequestID, blk.ID(), blk.ID()); err != nil {
 		t.Fatal(err)
 	}
 
@@ -2170,7 +2154,7 @@ func TestEngineBuildBlockLimit(t *testing.T) {
 		}
 	}
 
-	if err := te.Chits(context.Background(), vdr, reqID, []ids.ID{blk0.ID()}, nil); err != nil {
+	if err := te.Chits(context.Background(), vdr, reqID, blk0.ID(), blk0.ID()); err != nil {
 		t.Fatal(err)
 	}
 
@@ -2252,7 +2236,7 @@ func TestEngineReceiveNewRejectedBlock(t *testing.T) {
 		t.Fatalf("Didn't query for the new block")
 	}
 
-	if err := te.Chits(context.Background(), vdr, reqID, []ids.ID{acceptedBlk.ID()}, nil); err != nil {
+	if err := te.Chits(context.Background(), vdr, reqID, acceptedBlk.ID(), acceptedBlk.ID()); err != nil {
 		t.Fatal(err)
 	}
 
@@ -2367,7 +2351,7 @@ func TestEngineRejectionAmplification(t *testing.T) {
 		}
 	}
 
-	if err := te.Chits(context.Background(), vdr, reqID, []ids.ID{acceptedBlk.ID()}, nil); err != nil {
+	if err := te.Chits(context.Background(), vdr, reqID, acceptedBlk.ID(), acceptedBlk.ID()); err != nil {
 		t.Fatal(err)
 	}
 
@@ -2488,7 +2472,7 @@ func TestEngineTransitiveRejectionAmplificationDueToRejectedParent(t *testing.T)
 		t.Fatalf("Didn't query for the new block")
 	}
 
-	if err := te.Chits(context.Background(), vdr, reqID, []ids.ID{acceptedBlk.ID()}, nil); err != nil {
+	if err := te.Chits(context.Background(), vdr, reqID, acceptedBlk.ID(), acceptedBlk.ID()); err != nil {
 		t.Fatal(err)
 	}
 
@@ -2597,7 +2581,7 @@ func TestEngineTransitiveRejectionAmplificationDueToInvalidParent(t *testing.T)
 		}
 	}
 
-	if err := te.Chits(context.Background(), vdr, reqID, []ids.ID{acceptedBlk.ID()}, nil); err != nil {
+	if err := te.Chits(context.Background(), vdr, reqID, acceptedBlk.ID(), acceptedBlk.ID()); err != nil {
 		t.Fatal(err)
 	}
 
@@ -2810,7 +2794,7 @@ func TestEngineBubbleVotesThroughInvalidBlock(t *testing.T) {
 
 	// Now we are expecting a Chits message, and we receive it for [blk2]
 	// instead of [blk1]. This will cause the node to again request [blk2].
-	require.NoError(te.Chits(context.Background(), vdr, *queryRequestID, []ids.ID{blk2.ID()}, nil))
+	require.NoError(te.Chits(context.Background(), vdr, *queryRequestID, blk2.ID(), blk2.ID()))
 
 	// The votes should be bubbled through [blk2] despite the fact that it is
 	// failing verification.
@@ -2848,7 +2832,7 @@ func TestEngineBubbleVotesThroughInvalidBlock(t *testing.T) {
 	require.True(*queried)
 
 	// After a single vote for [blk2], it should be marked as accepted.
-	require.NoError(te.Chits(context.Background(), vdr, *queryRequestID, []ids.ID{blk2.ID()}, nil))
+	require.NoError(te.Chits(context.Background(), vdr, *queryRequestID, blk2.ID(), blk2.ID()))
 	require.Equal(choices.Accepted, blk2.Status())
 }
 
@@ -2989,7 +2973,7 @@ func TestEngineBubbleVotesThroughInvalidChain(t *testing.T) {
 
 	// Now we are expecting a Chits message and we receive it for [blk3].
 	// This will cause the node to again request [blk3].
-	require.NoError(te.Chits(context.Background(), vdr, *queryRequestID, []ids.ID{blk3.ID()}, nil))
+	require.NoError(te.Chits(context.Background(), vdr, *queryRequestID, blk3.ID(), blk3.ID()))
 
 	// Drop the re-request for [blk3] to cause the poll to terminate. The votes
 	// should be bubbled through [blk3] despite the fact that it hasn't been
@@ -3119,8 +3103,8 @@ func TestEngineBuildBlockWithCachedNonVerifiedParent(t *testing.T) {
 	require.NoError(te.Put(context.Background(), vdr, 0, parentBlkA.BytesV))
 
 	// Give 2 chits for [parentBlkA]/[parentBlkB]
-	require.NoError(te.Chits(context.Background(), vdr, *queryRequestAID, []ids.ID{parentBlkB.IDV}, nil))
-	require.NoError(te.Chits(context.Background(), vdr, *queryRequestGPID, []ids.ID{parentBlkB.IDV}, nil))
+	require.NoError(te.Chits(context.Background(), vdr, *queryRequestAID, parentBlkB.IDV, parentBlkB.IDV))
+	require.NoError(te.Chits(context.Background(), vdr, *queryRequestGPID, parentBlkB.IDV, parentBlkB.IDV))
 
 	// Assert that the blocks' statuses are correct.
 	// The evicted [parentBlkA] shouldn't be changed.
@@ -3232,8 +3216,7 @@ func TestEngineApplyAcceptedFrontierInQueryFailed(t *testing.T) {
 		*queryRequestID = requestID
 	}
 
-	blkIDs := []ids.ID{blk.ID()}
-	require.NoError(te.Chits(context.Background(), vdr, *queryRequestID, blkIDs, blkIDs))
+	require.NoError(te.Chits(context.Background(), vdr, *queryRequestID, blk.ID(), blk.ID()))
 
 	require.Equal(choices.Processing, blk.Status())
 
diff --git a/snow/networking/handler/handler.go b/snow/networking/handler/handler.go
index 3a600a1799c6..41d6e6cdc454 100644
--- a/snow/networking/handler/handler.go
+++ b/snow/networking/handler/handler.go
@@ -712,31 +712,31 @@ func (h *handler) handleSyncMsg(ctx context.Context, msg Message) error {
 		return engine.PullQuery(ctx, nodeID, msg.RequestId, containerID)
 
 	case *p2p.Chits:
-		votes, err := getIDs(msg.PreferredContainerIds)
+		preferredID, err := ids.ToID(msg.PreferredId)
 		if err != nil {
 			h.ctx.Log.Debug("message with invalid field",
 				zap.Stringer("nodeID", nodeID),
 				zap.Stringer("messageOp", message.ChitsOp),
 				zap.Uint32("requestID", msg.RequestId),
-				zap.String("field", "PreferredContainerIDs"),
+				zap.String("field", "PreferredID"),
 				zap.Error(err),
 			)
 			return engine.QueryFailed(ctx, nodeID, msg.RequestId)
 		}
 
-		accepted, err := getIDs(msg.AcceptedContainerIds)
+		acceptedID, err := ids.ToID(msg.AcceptedId)
 		if err != nil {
 			h.ctx.Log.Debug("message with invalid field",
 				zap.Stringer("nodeID", nodeID),
 				zap.Stringer("messageOp", message.ChitsOp),
 				zap.Uint32("requestID", msg.RequestId),
-				zap.String("field", "AcceptedContainerIDs"),
+				zap.String("field", "AcceptedID"),
 				zap.Error(err),
 			)
 			return engine.QueryFailed(ctx, nodeID, msg.RequestId)
 		}
 
-		return engine.Chits(ctx, nodeID, msg.RequestId, votes, accepted)
+		return engine.Chits(ctx, nodeID, msg.RequestId, preferredID, acceptedID)
 
 	case *message.QueryFailed:
 		return engine.QueryFailed(ctx, nodeID, msg.RequestID)
diff --git a/snow/networking/handler/handler_test.go b/snow/networking/handler/handler_test.go
index ccc694ae1991..9800a643ec5d 100644
--- a/snow/networking/handler/handler_test.go
+++ b/snow/networking/handler/handler_test.go
@@ -584,7 +584,7 @@ func TestDynamicEngineTypeDispatch(t *testing.T) {
 			engine.ContextF = func() *snow.ConsensusContext {
 				return ctx
 			}
-			engine.ChitsF = func(ctx context.Context, nodeID ids.NodeID, requestID uint32, preferredIDs []ids.ID, acceptedIDs []ids.ID) error {
+			engine.ChitsF = func(context.Context, ids.NodeID, uint32, ids.ID, ids.ID) error {
 				close(messageReceived)
 				return nil
 			}
@@ -605,8 +605,8 @@ func TestDynamicEngineTypeDispatch(t *testing.T) {
 				InboundMessage: message.InboundChits(
 					ids.Empty,
 					uint32(0),
-					nil,
-					nil,
+					ids.Empty,
+					ids.Empty,
 					ids.EmptyNodeID,
 				),
 				EngineType: test.requestedEngineType,
diff --git a/snow/networking/router/chain_router_test.go b/snow/networking/router/chain_router_test.go
index 2027f2ddb2b7..6d886c078e9d 100644
--- a/snow/networking/router/chain_router_test.go
+++ b/snow/networking/router/chain_router_test.go
@@ -1022,8 +1022,8 @@ func TestRouterClearTimeouts(t *testing.T) {
 		msg := message.InboundChits(
 			ctx.ChainID,
 			requestID,
-			nil,
-			nil,
+			ids.Empty,
+			ids.Empty,
 			nodeID,
 		)
 		chainRouter.HandleInbound(context.Background(), msg)
diff --git a/snow/networking/sender/sender.go b/snow/networking/sender/sender.go
index afacef3a5d51..b8d9bee74f41 100644
--- a/snow/networking/sender/sender.go
+++ b/snow/networking/sender/sender.go
@@ -1153,7 +1153,7 @@ func (s *sender) SendPullQuery(ctx context.Context, nodeIDs set.Set[ids.NodeID],
 }
 
 // SendChits sends chits
-func (s *sender) SendChits(ctx context.Context, nodeID ids.NodeID, requestID uint32, votes, accepted []ids.ID) {
+func (s *sender) SendChits(ctx context.Context, nodeID ids.NodeID, requestID uint32, preferredID, acceptedID ids.ID) {
 	ctx = utils.Detach(ctx)
 
 	// If [nodeID] is myself, send this message directly
@@ -1162,8 +1162,8 @@ func (s *sender) SendChits(ctx context.Context, nodeID ids.NodeID, requestID uin
 		inMsg := message.InboundChits(
 			s.ctx.ChainID,
 			requestID,
-			votes,
-			accepted,
+			preferredID,
+			acceptedID,
 			nodeID,
 		)
 		go s.router.HandleInbound(ctx, inMsg)
@@ -1171,13 +1171,14 @@ func (s *sender) SendChits(ctx context.Context, nodeID ids.NodeID, requestID uin
 	}
 
 	// Create the outbound message.
-	outMsg, err := s.msgCreator.Chits(s.ctx.ChainID, requestID, votes, accepted)
+	outMsg, err := s.msgCreator.Chits(s.ctx.ChainID, requestID, preferredID, acceptedID)
 	if err != nil {
 		s.ctx.Log.Error("failed to build message",
 			zap.Stringer("messageOp", message.ChitsOp),
 			zap.Stringer("chainID", s.ctx.ChainID),
 			zap.Uint32("requestID", requestID),
-			zap.Stringers("containerIDs", votes),
+			zap.Stringer("preferredID", preferredID),
+			zap.Stringer("acceptedID", acceptedID),
 			zap.Error(err),
 		)
 		return
@@ -1198,7 +1199,8 @@ func (s *sender) SendChits(ctx context.Context, nodeID ids.NodeID, requestID uin
 			zap.Stringer("nodeID", nodeID),
 			zap.Stringer("chainID", s.ctx.ChainID),
 			zap.Uint32("requestID", requestID),
-			zap.Stringers("containerIDs", votes),
+			zap.Stringer("preferredID", preferredID),
+			zap.Stringer("acceptedID", acceptedID),
 		)
 	}
 }
diff --git a/snow/networking/sender/traced_sender.go b/snow/networking/sender/traced_sender.go
index a6ffe7f4ab21..a60118af470f 100644
--- a/snow/networking/sender/traced_sender.go
+++ b/snow/networking/sender/traced_sender.go
@@ -177,16 +177,16 @@ func (s *tracedSender) SendPullQuery(ctx context.Context, nodeIDs set.Set[ids.No
 	s.sender.SendPullQuery(ctx, nodeIDs, requestID, containerID)
 }
 
-func (s *tracedSender) SendChits(ctx context.Context, nodeID ids.NodeID, requestID uint32, votes []ids.ID, accepted []ids.ID) {
+func (s *tracedSender) SendChits(ctx context.Context, nodeID ids.NodeID, requestID uint32, preferredID ids.ID, acceptedID ids.ID) {
 	ctx, span := s.tracer.Start(ctx, "tracedSender.SendChits", oteltrace.WithAttributes(
 		attribute.Stringer("recipients", nodeID),
 		attribute.Int64("requestID", int64(requestID)),
-		attribute.Int("numVotes", len(votes)),
-		attribute.Int("numAccepted", len(accepted)),
+		attribute.Stringer("preferredID", preferredID),
+		attribute.Stringer("acceptedID", acceptedID),
 	))
 	defer span.End()
 
-	s.sender.SendChits(ctx, nodeID, requestID, votes, accepted)
+	s.sender.SendChits(ctx, nodeID, requestID, preferredID, acceptedID)
 }
 
 func (s *tracedSender) SendCrossChainAppRequest(ctx context.Context, chainID ids.ID, requestID uint32, appRequestBytes []byte) error {