diff --git a/chat.pb.go b/chat.pb.go
index 079d434..f90473b 100644
--- a/chat.pb.go
+++ b/chat.pb.go
@@ -205,6 +205,64 @@ func (x *Topic) GetCreatedAt() *timestamppb.Timestamp {
 	return nil
 }
 
+// AgentDelegation is optional machine-readable routing metadata on AGENT
+// messages. Text content remains the human-readable task description;
+// delegation only carries deterministic target + kind. Delegation is NOT
+// human approval and does NOT authorize mutation.
+type AgentDelegation struct {
+	state protoimpl.MessageState `protogen:"open.v1"`
+	// Canonical Chat author_id (UUID) of the target AGENT participant.
+	TargetAuthorId string `protobuf:"bytes,1,opt,name=target_author_id,json=targetAuthorId,proto3" json:"target_author_id,omitempty"`
+	// Stage 8 kinds: INVESTIGATE.
+	Kind          string `protobuf:"bytes,2,opt,name=kind,proto3" json:"kind,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *AgentDelegation) Reset() {
+	*x = AgentDelegation{}
+	mi := &file_chat_proto_msgTypes[1]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *AgentDelegation) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*AgentDelegation) ProtoMessage() {}
+
+func (x *AgentDelegation) ProtoReflect() protoreflect.Message {
+	mi := &file_chat_proto_msgTypes[1]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use AgentDelegation.ProtoReflect.Descriptor instead.
+func (*AgentDelegation) Descriptor() ([]byte, []int) {
+	return file_chat_proto_rawDescGZIP(), []int{1}
+}
+
+func (x *AgentDelegation) GetTargetAuthorId() string {
+	if x != nil {
+		return x.TargetAuthorId
+	}
+	return ""
+}
+
+func (x *AgentDelegation) GetKind() string {
+	if x != nil {
+		return x.Kind
+	}
+	return ""
+}
+
 type Message struct {
 	state            protoimpl.MessageState `protogen:"open.v1"`
 	Id               string                 `protobuf:"bytes,1,opt,name=id,proto3" json:"id,omitempty"`                             // UUID, canonical message id
@@ -218,13 +276,15 @@ type Message struct {
 	RootMessageId    string                 `protobuf:"bytes,9,opt,name=root_message_id,json=rootMessageId,proto3" json:"root_message_id,omitempty"`                  // root of the reply chain (== id for non-replies)
 	ReplyDepth       int32                  `protobuf:"varint,10,opt,name=reply_depth,json=replyDepth,proto3" json:"reply_depth,omitempty"`                           // 0 for non-replies, parent depth + 1 for replies; hard max 20
 	CreatedAt        *timestamppb.Timestamp `protobuf:"bytes,11,opt,name=created_at,json=createdAt,proto3" json:"created_at,omitempty"`                               // original creation time; age = now - created_at
-	unknownFields    protoimpl.UnknownFields
-	sizeCache        protoimpl.SizeCache
+	// Optional; only set on AGENT messages that intentionally delegate.
+	Delegation    *AgentDelegation `protobuf:"bytes,12,opt,name=delegation,proto3,oneof" json:"delegation,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
 }
 
 func (x *Message) Reset() {
 	*x = Message{}
-	mi := &file_chat_proto_msgTypes[1]
+	mi := &file_chat_proto_msgTypes[2]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -236,7 +296,7 @@ func (x *Message) String() string {
 func (*Message) ProtoMessage() {}
 
 func (x *Message) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[1]
+	mi := &file_chat_proto_msgTypes[2]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -249,7 +309,7 @@ func (x *Message) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use Message.ProtoReflect.Descriptor instead.
 func (*Message) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{1}
+	return file_chat_proto_rawDescGZIP(), []int{2}
 }
 
 func (x *Message) GetId() string {
@@ -329,6 +389,13 @@ func (x *Message) GetCreatedAt() *timestamppb.Timestamp {
 	return nil
 }
 
+func (x *Message) GetDelegation() *AgentDelegation {
+	if x != nil {
+		return x.Delegation
+	}
+	return nil
+}
+
 type ListTopicsRequest struct {
 	state         protoimpl.MessageState `protogen:"open.v1"`
 	unknownFields protoimpl.UnknownFields
@@ -337,7 +404,7 @@ type ListTopicsRequest struct {
 
 func (x *ListTopicsRequest) Reset() {
 	*x = ListTopicsRequest{}
-	mi := &file_chat_proto_msgTypes[2]
+	mi := &file_chat_proto_msgTypes[3]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -349,7 +416,7 @@ func (x *ListTopicsRequest) String() string {
 func (*ListTopicsRequest) ProtoMessage() {}
 
 func (x *ListTopicsRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[2]
+	mi := &file_chat_proto_msgTypes[3]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -362,7 +429,7 @@ func (x *ListTopicsRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use ListTopicsRequest.ProtoReflect.Descriptor instead.
 func (*ListTopicsRequest) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{2}
+	return file_chat_proto_rawDescGZIP(), []int{3}
 }
 
 type ListTopicsResponse struct {
@@ -374,7 +441,7 @@ type ListTopicsResponse struct {
 
 func (x *ListTopicsResponse) Reset() {
 	*x = ListTopicsResponse{}
-	mi := &file_chat_proto_msgTypes[3]
+	mi := &file_chat_proto_msgTypes[4]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -386,7 +453,7 @@ func (x *ListTopicsResponse) String() string {
 func (*ListTopicsResponse) ProtoMessage() {}
 
 func (x *ListTopicsResponse) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[3]
+	mi := &file_chat_proto_msgTypes[4]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -399,7 +466,7 @@ func (x *ListTopicsResponse) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use ListTopicsResponse.ProtoReflect.Descriptor instead.
 func (*ListTopicsResponse) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{3}
+	return file_chat_proto_rawDescGZIP(), []int{4}
 }
 
 func (x *ListTopicsResponse) GetTopics() []*Topic {
@@ -422,7 +489,7 @@ type GetTopicRequest struct {
 
 func (x *GetTopicRequest) Reset() {
 	*x = GetTopicRequest{}
-	mi := &file_chat_proto_msgTypes[4]
+	mi := &file_chat_proto_msgTypes[5]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -434,7 +501,7 @@ func (x *GetTopicRequest) String() string {
 func (*GetTopicRequest) ProtoMessage() {}
 
 func (x *GetTopicRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[4]
+	mi := &file_chat_proto_msgTypes[5]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -447,7 +514,7 @@ func (x *GetTopicRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use GetTopicRequest.ProtoReflect.Descriptor instead.
 func (*GetTopicRequest) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{4}
+	return file_chat_proto_rawDescGZIP(), []int{5}
 }
 
 func (x *GetTopicRequest) GetSelector() isGetTopicRequest_Selector {
@@ -501,7 +568,7 @@ type CreateTopicRequest struct {
 
 func (x *CreateTopicRequest) Reset() {
 	*x = CreateTopicRequest{}
-	mi := &file_chat_proto_msgTypes[5]
+	mi := &file_chat_proto_msgTypes[6]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -513,7 +580,7 @@ func (x *CreateTopicRequest) String() string {
 func (*CreateTopicRequest) ProtoMessage() {}
 
 func (x *CreateTopicRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[5]
+	mi := &file_chat_proto_msgTypes[6]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -526,7 +593,7 @@ func (x *CreateTopicRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use CreateTopicRequest.ProtoReflect.Descriptor instead.
 func (*CreateTopicRequest) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{5}
+	return file_chat_proto_rawDescGZIP(), []int{6}
 }
 
 func (x *CreateTopicRequest) GetSlug() string {
@@ -553,7 +620,7 @@ type UpdateTopicRequest struct {
 
 func (x *UpdateTopicRequest) Reset() {
 	*x = UpdateTopicRequest{}
-	mi := &file_chat_proto_msgTypes[6]
+	mi := &file_chat_proto_msgTypes[7]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -565,7 +632,7 @@ func (x *UpdateTopicRequest) String() string {
 func (*UpdateTopicRequest) ProtoMessage() {}
 
 func (x *UpdateTopicRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[6]
+	mi := &file_chat_proto_msgTypes[7]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -578,7 +645,7 @@ func (x *UpdateTopicRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use UpdateTopicRequest.ProtoReflect.Descriptor instead.
 func (*UpdateTopicRequest) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{6}
+	return file_chat_proto_rawDescGZIP(), []int{7}
 }
 
 func (x *UpdateTopicRequest) GetId() string {
@@ -606,13 +673,15 @@ type PostMessageRequest struct {
 	// Idempotency key: retrying PostMessage with the same author_id and key
 	// returns the original message instead of creating a duplicate.
 	IdempotencyKey string `protobuf:"bytes,7,opt,name=idempotency_key,json=idempotencyKey,proto3" json:"idempotency_key,omitempty"`
-	unknownFields  protoimpl.UnknownFields
-	sizeCache      protoimpl.SizeCache
+	// Agents must not use this path; Human HTTP PostMessage rejects delegation.
+	Delegation    *AgentDelegation `protobuf:"bytes,8,opt,name=delegation,proto3,oneof" json:"delegation,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
 }
 
 func (x *PostMessageRequest) Reset() {
 	*x = PostMessageRequest{}
-	mi := &file_chat_proto_msgTypes[7]
+	mi := &file_chat_proto_msgTypes[8]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -624,7 +693,7 @@ func (x *PostMessageRequest) String() string {
 func (*PostMessageRequest) ProtoMessage() {}
 
 func (x *PostMessageRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[7]
+	mi := &file_chat_proto_msgTypes[8]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -637,7 +706,7 @@ func (x *PostMessageRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use PostMessageRequest.ProtoReflect.Descriptor instead.
 func (*PostMessageRequest) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{7}
+	return file_chat_proto_rawDescGZIP(), []int{8}
 }
 
 func (x *PostMessageRequest) GetTopicId() string {
@@ -689,6 +758,13 @@ func (x *PostMessageRequest) GetIdempotencyKey() string {
 	return ""
 }
 
+func (x *PostMessageRequest) GetDelegation() *AgentDelegation {
+	if x != nil {
+		return x.Delegation
+	}
+	return nil
+}
+
 type AgentPostMessageRequest struct {
 	state            protoimpl.MessageState `protogen:"open.v1"`
 	TopicId          string                 `protobuf:"bytes,1,opt,name=topic_id,json=topicId,proto3" json:"topic_id,omitempty"`
@@ -697,13 +773,16 @@ type AgentPostMessageRequest struct {
 	// Mandatory: retrying with the same key returns the original message
 	// (duplicated=true) instead of creating a duplicate.
 	IdempotencyKey string `protobuf:"bytes,4,opt,name=idempotency_key,json=idempotencyKey,proto3" json:"idempotency_key,omitempty"`
-	unknownFields  protoimpl.UnknownFields
-	sizeCache      protoimpl.SizeCache
+	// Optional machine-readable delegation. Server validates target is an
+	// existing AGENT participant; sender identity comes from auth, not client.
+	Delegation    *AgentDelegation `protobuf:"bytes,5,opt,name=delegation,proto3,oneof" json:"delegation,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
 }
 
 func (x *AgentPostMessageRequest) Reset() {
 	*x = AgentPostMessageRequest{}
-	mi := &file_chat_proto_msgTypes[8]
+	mi := &file_chat_proto_msgTypes[9]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -715,7 +794,7 @@ func (x *AgentPostMessageRequest) String() string {
 func (*AgentPostMessageRequest) ProtoMessage() {}
 
 func (x *AgentPostMessageRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[8]
+	mi := &file_chat_proto_msgTypes[9]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -728,7 +807,7 @@ func (x *AgentPostMessageRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use AgentPostMessageRequest.ProtoReflect.Descriptor instead.
 func (*AgentPostMessageRequest) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{8}
+	return file_chat_proto_rawDescGZIP(), []int{9}
 }
 
 func (x *AgentPostMessageRequest) GetTopicId() string {
@@ -759,6 +838,13 @@ func (x *AgentPostMessageRequest) GetIdempotencyKey() string {
 	return ""
 }
 
+func (x *AgentPostMessageRequest) GetDelegation() *AgentDelegation {
+	if x != nil {
+		return x.Delegation
+	}
+	return nil
+}
+
 type PostMessageResponse struct {
 	state         protoimpl.MessageState `protogen:"open.v1"`
 	Message       *Message               `protobuf:"bytes,1,opt,name=message,proto3" json:"message,omitempty"`
@@ -769,7 +855,7 @@ type PostMessageResponse struct {
 
 func (x *PostMessageResponse) Reset() {
 	*x = PostMessageResponse{}
-	mi := &file_chat_proto_msgTypes[9]
+	mi := &file_chat_proto_msgTypes[10]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -781,7 +867,7 @@ func (x *PostMessageResponse) String() string {
 func (*PostMessageResponse) ProtoMessage() {}
 
 func (x *PostMessageResponse) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[9]
+	mi := &file_chat_proto_msgTypes[10]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -794,7 +880,7 @@ func (x *PostMessageResponse) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use PostMessageResponse.ProtoReflect.Descriptor instead.
 func (*PostMessageResponse) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{9}
+	return file_chat_proto_rawDescGZIP(), []int{10}
 }
 
 func (x *PostMessageResponse) GetMessage() *Message {
@@ -820,7 +906,7 @@ type GetMessageRequest struct {
 
 func (x *GetMessageRequest) Reset() {
 	*x = GetMessageRequest{}
-	mi := &file_chat_proto_msgTypes[10]
+	mi := &file_chat_proto_msgTypes[11]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -832,7 +918,7 @@ func (x *GetMessageRequest) String() string {
 func (*GetMessageRequest) ProtoMessage() {}
 
 func (x *GetMessageRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[10]
+	mi := &file_chat_proto_msgTypes[11]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -845,7 +931,7 @@ func (x *GetMessageRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use GetMessageRequest.ProtoReflect.Descriptor instead.
 func (*GetMessageRequest) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{10}
+	return file_chat_proto_rawDescGZIP(), []int{11}
 }
 
 func (x *GetMessageRequest) GetMessageId() string {
@@ -872,7 +958,7 @@ type HistoryRequest struct {
 
 func (x *HistoryRequest) Reset() {
 	*x = HistoryRequest{}
-	mi := &file_chat_proto_msgTypes[11]
+	mi := &file_chat_proto_msgTypes[12]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -884,7 +970,7 @@ func (x *HistoryRequest) String() string {
 func (*HistoryRequest) ProtoMessage() {}
 
 func (x *HistoryRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[11]
+	mi := &file_chat_proto_msgTypes[12]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -897,7 +983,7 @@ func (x *HistoryRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use HistoryRequest.ProtoReflect.Descriptor instead.
 func (*HistoryRequest) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{11}
+	return file_chat_proto_rawDescGZIP(), []int{12}
 }
 
 func (x *HistoryRequest) GetTopicId() string {
@@ -939,7 +1025,7 @@ type HistoryResponse struct {
 
 func (x *HistoryResponse) Reset() {
 	*x = HistoryResponse{}
-	mi := &file_chat_proto_msgTypes[12]
+	mi := &file_chat_proto_msgTypes[13]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -951,7 +1037,7 @@ func (x *HistoryResponse) String() string {
 func (*HistoryResponse) ProtoMessage() {}
 
 func (x *HistoryResponse) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[12]
+	mi := &file_chat_proto_msgTypes[13]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -964,7 +1050,7 @@ func (x *HistoryResponse) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use HistoryResponse.ProtoReflect.Descriptor instead.
 func (*HistoryResponse) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{12}
+	return file_chat_proto_rawDescGZIP(), []int{13}
 }
 
 func (x *HistoryResponse) GetMessages() []*Message {
@@ -990,7 +1076,7 @@ type SubscribeRequest struct {
 
 func (x *SubscribeRequest) Reset() {
 	*x = SubscribeRequest{}
-	mi := &file_chat_proto_msgTypes[13]
+	mi := &file_chat_proto_msgTypes[14]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1002,7 +1088,7 @@ func (x *SubscribeRequest) String() string {
 func (*SubscribeRequest) ProtoMessage() {}
 
 func (x *SubscribeRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[13]
+	mi := &file_chat_proto_msgTypes[14]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1015,7 +1101,7 @@ func (x *SubscribeRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use SubscribeRequest.ProtoReflect.Descriptor instead.
 func (*SubscribeRequest) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{13}
+	return file_chat_proto_rawDescGZIP(), []int{14}
 }
 
 func (x *SubscribeRequest) GetTopicId() string {
@@ -1052,7 +1138,7 @@ type DeliveryMessage struct {
 
 func (x *DeliveryMessage) Reset() {
 	*x = DeliveryMessage{}
-	mi := &file_chat_proto_msgTypes[14]
+	mi := &file_chat_proto_msgTypes[15]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1064,7 +1150,7 @@ func (x *DeliveryMessage) String() string {
 func (*DeliveryMessage) ProtoMessage() {}
 
 func (x *DeliveryMessage) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[14]
+	mi := &file_chat_proto_msgTypes[15]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1077,7 +1163,7 @@ func (x *DeliveryMessage) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use DeliveryMessage.ProtoReflect.Descriptor instead.
 func (*DeliveryMessage) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{14}
+	return file_chat_proto_rawDescGZIP(), []int{15}
 }
 
 func (x *DeliveryMessage) GetMessage() *Message {
@@ -1129,7 +1215,7 @@ type AcknowledgeRequest struct {
 
 func (x *AcknowledgeRequest) Reset() {
 	*x = AcknowledgeRequest{}
-	mi := &file_chat_proto_msgTypes[15]
+	mi := &file_chat_proto_msgTypes[16]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1141,7 +1227,7 @@ func (x *AcknowledgeRequest) String() string {
 func (*AcknowledgeRequest) ProtoMessage() {}
 
 func (x *AcknowledgeRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[15]
+	mi := &file_chat_proto_msgTypes[16]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1154,7 +1240,7 @@ func (x *AcknowledgeRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use AcknowledgeRequest.ProtoReflect.Descriptor instead.
 func (*AcknowledgeRequest) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{15}
+	return file_chat_proto_rawDescGZIP(), []int{16}
 }
 
 func (x *AcknowledgeRequest) GetTopicId() string {
@@ -1194,7 +1280,7 @@ type AcknowledgeResponse struct {
 
 func (x *AcknowledgeResponse) Reset() {
 	*x = AcknowledgeResponse{}
-	mi := &file_chat_proto_msgTypes[16]
+	mi := &file_chat_proto_msgTypes[17]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1206,7 +1292,7 @@ func (x *AcknowledgeResponse) String() string {
 func (*AcknowledgeResponse) ProtoMessage() {}
 
 func (x *AcknowledgeResponse) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[16]
+	mi := &file_chat_proto_msgTypes[17]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1219,7 +1305,7 @@ func (x *AcknowledgeResponse) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use AcknowledgeResponse.ProtoReflect.Descriptor instead.
 func (*AcknowledgeResponse) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{16}
+	return file_chat_proto_rawDescGZIP(), []int{17}
 }
 
 func (x *AcknowledgeResponse) GetLastAckSequence() int64 {
@@ -1257,7 +1343,7 @@ type Participant struct {
 
 func (x *Participant) Reset() {
 	*x = Participant{}
-	mi := &file_chat_proto_msgTypes[17]
+	mi := &file_chat_proto_msgTypes[18]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1269,7 +1355,7 @@ func (x *Participant) String() string {
 func (*Participant) ProtoMessage() {}
 
 func (x *Participant) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[17]
+	mi := &file_chat_proto_msgTypes[18]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1282,7 +1368,7 @@ func (x *Participant) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use Participant.ProtoReflect.Descriptor instead.
 func (*Participant) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{17}
+	return file_chat_proto_rawDescGZIP(), []int{18}
 }
 
 func (x *Participant) GetAuthorId() string {
@@ -1399,7 +1485,7 @@ type GetParticipantRequest struct {
 
 func (x *GetParticipantRequest) Reset() {
 	*x = GetParticipantRequest{}
-	mi := &file_chat_proto_msgTypes[18]
+	mi := &file_chat_proto_msgTypes[19]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1411,7 +1497,7 @@ func (x *GetParticipantRequest) String() string {
 func (*GetParticipantRequest) ProtoMessage() {}
 
 func (x *GetParticipantRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[18]
+	mi := &file_chat_proto_msgTypes[19]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1424,7 +1510,7 @@ func (x *GetParticipantRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use GetParticipantRequest.ProtoReflect.Descriptor instead.
 func (*GetParticipantRequest) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{18}
+	return file_chat_proto_rawDescGZIP(), []int{19}
 }
 
 func (x *GetParticipantRequest) GetAuthorId() string {
@@ -1443,7 +1529,7 @@ type BatchGetParticipantsRequest struct {
 
 func (x *BatchGetParticipantsRequest) Reset() {
 	*x = BatchGetParticipantsRequest{}
-	mi := &file_chat_proto_msgTypes[19]
+	mi := &file_chat_proto_msgTypes[20]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1455,7 +1541,7 @@ func (x *BatchGetParticipantsRequest) String() string {
 func (*BatchGetParticipantsRequest) ProtoMessage() {}
 
 func (x *BatchGetParticipantsRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[19]
+	mi := &file_chat_proto_msgTypes[20]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1468,7 +1554,7 @@ func (x *BatchGetParticipantsRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use BatchGetParticipantsRequest.ProtoReflect.Descriptor instead.
 func (*BatchGetParticipantsRequest) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{19}
+	return file_chat_proto_rawDescGZIP(), []int{20}
 }
 
 func (x *BatchGetParticipantsRequest) GetAuthorIds() []string {
@@ -1487,7 +1573,7 @@ type BatchGetParticipantsResponse struct {
 
 func (x *BatchGetParticipantsResponse) Reset() {
 	*x = BatchGetParticipantsResponse{}
-	mi := &file_chat_proto_msgTypes[20]
+	mi := &file_chat_proto_msgTypes[21]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1499,7 +1585,7 @@ func (x *BatchGetParticipantsResponse) String() string {
 func (*BatchGetParticipantsResponse) ProtoMessage() {}
 
 func (x *BatchGetParticipantsResponse) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[20]
+	mi := &file_chat_proto_msgTypes[21]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1512,7 +1598,7 @@ func (x *BatchGetParticipantsResponse) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use BatchGetParticipantsResponse.ProtoReflect.Descriptor instead.
 func (*BatchGetParticipantsResponse) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{20}
+	return file_chat_proto_rawDescGZIP(), []int{21}
 }
 
 func (x *BatchGetParticipantsResponse) GetParticipants() []*Participant {
@@ -1531,7 +1617,7 @@ type ListTopicParticipantsRequest struct {
 
 func (x *ListTopicParticipantsRequest) Reset() {
 	*x = ListTopicParticipantsRequest{}
-	mi := &file_chat_proto_msgTypes[21]
+	mi := &file_chat_proto_msgTypes[22]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1543,7 +1629,7 @@ func (x *ListTopicParticipantsRequest) String() string {
 func (*ListTopicParticipantsRequest) ProtoMessage() {}
 
 func (x *ListTopicParticipantsRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[21]
+	mi := &file_chat_proto_msgTypes[22]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1556,7 +1642,7 @@ func (x *ListTopicParticipantsRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use ListTopicParticipantsRequest.ProtoReflect.Descriptor instead.
 func (*ListTopicParticipantsRequest) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{21}
+	return file_chat_proto_rawDescGZIP(), []int{22}
 }
 
 func (x *ListTopicParticipantsRequest) GetTopicId() string {
@@ -1575,7 +1661,7 @@ type ListTopicParticipantsResponse struct {
 
 func (x *ListTopicParticipantsResponse) Reset() {
 	*x = ListTopicParticipantsResponse{}
-	mi := &file_chat_proto_msgTypes[22]
+	mi := &file_chat_proto_msgTypes[23]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1587,7 +1673,7 @@ func (x *ListTopicParticipantsResponse) String() string {
 func (*ListTopicParticipantsResponse) ProtoMessage() {}
 
 func (x *ListTopicParticipantsResponse) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[22]
+	mi := &file_chat_proto_msgTypes[23]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1600,7 +1686,7 @@ func (x *ListTopicParticipantsResponse) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use ListTopicParticipantsResponse.ProtoReflect.Descriptor instead.
 func (*ListTopicParticipantsResponse) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{22}
+	return file_chat_proto_rawDescGZIP(), []int{23}
 }
 
 func (x *ListTopicParticipantsResponse) GetParticipants() []*Participant {
@@ -1618,7 +1704,7 @@ type GetMyParticipantRequest struct {
 
 func (x *GetMyParticipantRequest) Reset() {
 	*x = GetMyParticipantRequest{}
-	mi := &file_chat_proto_msgTypes[23]
+	mi := &file_chat_proto_msgTypes[24]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1630,7 +1716,7 @@ func (x *GetMyParticipantRequest) String() string {
 func (*GetMyParticipantRequest) ProtoMessage() {}
 
 func (x *GetMyParticipantRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[23]
+	mi := &file_chat_proto_msgTypes[24]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1643,7 +1729,7 @@ func (x *GetMyParticipantRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use GetMyParticipantRequest.ProtoReflect.Descriptor instead.
 func (*GetMyParticipantRequest) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{23}
+	return file_chat_proto_rawDescGZIP(), []int{24}
 }
 
 // RegisterSelfProfileRequest carries only mutable public profile fields.
@@ -1662,7 +1748,7 @@ type RegisterSelfProfileRequest struct {
 
 func (x *RegisterSelfProfileRequest) Reset() {
 	*x = RegisterSelfProfileRequest{}
-	mi := &file_chat_proto_msgTypes[24]
+	mi := &file_chat_proto_msgTypes[25]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1674,7 +1760,7 @@ func (x *RegisterSelfProfileRequest) String() string {
 func (*RegisterSelfProfileRequest) ProtoMessage() {}
 
 func (x *RegisterSelfProfileRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[24]
+	mi := &file_chat_proto_msgTypes[25]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1687,7 +1773,7 @@ func (x *RegisterSelfProfileRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use RegisterSelfProfileRequest.ProtoReflect.Descriptor instead.
 func (*RegisterSelfProfileRequest) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{24}
+	return file_chat_proto_rawDescGZIP(), []int{25}
 }
 
 func (x *RegisterSelfProfileRequest) GetDisplayName() string {
@@ -1735,7 +1821,7 @@ type SyncMyTopicMembershipsRequest struct {
 
 func (x *SyncMyTopicMembershipsRequest) Reset() {
 	*x = SyncMyTopicMembershipsRequest{}
-	mi := &file_chat_proto_msgTypes[25]
+	mi := &file_chat_proto_msgTypes[26]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1747,7 +1833,7 @@ func (x *SyncMyTopicMembershipsRequest) String() string {
 func (*SyncMyTopicMembershipsRequest) ProtoMessage() {}
 
 func (x *SyncMyTopicMembershipsRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[25]
+	mi := &file_chat_proto_msgTypes[26]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1760,7 +1846,7 @@ func (x *SyncMyTopicMembershipsRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use SyncMyTopicMembershipsRequest.ProtoReflect.Descriptor instead.
 func (*SyncMyTopicMembershipsRequest) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{25}
+	return file_chat_proto_rawDescGZIP(), []int{26}
 }
 
 func (x *SyncMyTopicMembershipsRequest) GetTopicIds() []string {
@@ -1781,7 +1867,7 @@ type SyncMyTopicMembershipsResponse struct {
 
 func (x *SyncMyTopicMembershipsResponse) Reset() {
 	*x = SyncMyTopicMembershipsResponse{}
-	mi := &file_chat_proto_msgTypes[26]
+	mi := &file_chat_proto_msgTypes[27]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1793,7 +1879,7 @@ func (x *SyncMyTopicMembershipsResponse) String() string {
 func (*SyncMyTopicMembershipsResponse) ProtoMessage() {}
 
 func (x *SyncMyTopicMembershipsResponse) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[26]
+	mi := &file_chat_proto_msgTypes[27]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1806,7 +1892,7 @@ func (x *SyncMyTopicMembershipsResponse) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use SyncMyTopicMembershipsResponse.ProtoReflect.Descriptor instead.
 func (*SyncMyTopicMembershipsResponse) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{26}
+	return file_chat_proto_rawDescGZIP(), []int{27}
 }
 
 func (x *SyncMyTopicMembershipsResponse) GetTopicIds() []string {
@@ -1843,7 +1929,7 @@ type UploadSelfAvatarRequest struct {
 
 func (x *UploadSelfAvatarRequest) Reset() {
 	*x = UploadSelfAvatarRequest{}
-	mi := &file_chat_proto_msgTypes[27]
+	mi := &file_chat_proto_msgTypes[28]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1855,7 +1941,7 @@ func (x *UploadSelfAvatarRequest) String() string {
 func (*UploadSelfAvatarRequest) ProtoMessage() {}
 
 func (x *UploadSelfAvatarRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[27]
+	mi := &file_chat_proto_msgTypes[28]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1868,7 +1954,7 @@ func (x *UploadSelfAvatarRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use UploadSelfAvatarRequest.ProtoReflect.Descriptor instead.
 func (*UploadSelfAvatarRequest) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{27}
+	return file_chat_proto_rawDescGZIP(), []int{28}
 }
 
 func (x *UploadSelfAvatarRequest) GetContent() []byte {
@@ -1893,7 +1979,7 @@ type DeleteSelfAvatarRequest struct {
 
 func (x *DeleteSelfAvatarRequest) Reset() {
 	*x = DeleteSelfAvatarRequest{}
-	mi := &file_chat_proto_msgTypes[28]
+	mi := &file_chat_proto_msgTypes[29]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1905,7 +1991,7 @@ func (x *DeleteSelfAvatarRequest) String() string {
 func (*DeleteSelfAvatarRequest) ProtoMessage() {}
 
 func (x *DeleteSelfAvatarRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_chat_proto_msgTypes[28]
+	mi := &file_chat_proto_msgTypes[29]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1918,7 +2004,7 @@ func (x *DeleteSelfAvatarRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use DeleteSelfAvatarRequest.ProtoReflect.Descriptor instead.
 func (*DeleteSelfAvatarRequest) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{28}
+	return file_chat_proto_rawDescGZIP(), []int{29}
 }
 
 var File_chat_proto protoreflect.FileDescriptor
@@ -1932,7 +2018,10 @@ const file_chat_proto_rawDesc = "" +
 	"\x04slug\x18\x02 \x01(\tR\x04slug\x12!\n" +
 	"\fdisplay_name\x18\x03 \x01(\tR\vdisplayName\x129\n" +
 	"\n" +
-	"created_at\x18\x04 \x01(\v2\x1a.google.protobuf.TimestampR\tcreatedAt\"\xb7\x03\n" +
+	"created_at\x18\x04 \x01(\v2\x1a.google.protobuf.TimestampR\tcreatedAt\"O\n" +
+	"\x0fAgentDelegation\x12(\n" +
+	"\x10target_author_id\x18\x01 \x01(\tR\x0etargetAuthorId\x12\x12\n" +
+	"\x04kind\x18\x02 \x01(\tR\x04kind\"\x82\x04\n" +
 	"\aMessage\x12\x0e\n" +
 	"\x02id\x18\x01 \x01(\tR\x02id\x12\x1a\n" +
 	"\bsequence\x18\x02 \x01(\x03R\bsequence\x12\x19\n" +
@@ -1948,8 +2037,12 @@ const file_chat_proto_rawDesc = "" +
 	" \x01(\x05R\n" +
 	"replyDepth\x129\n" +
 	"\n" +
-	"created_at\x18\v \x01(\v2\x1a.google.protobuf.TimestampR\tcreatedAtB\x16\n" +
-	"\x14_reply_to_message_id\"\x13\n" +
+	"created_at\x18\v \x01(\v2\x1a.google.protobuf.TimestampR\tcreatedAt\x12:\n" +
+	"\n" +
+	"delegation\x18\f \x01(\v2\x15.chat.AgentDelegationH\x01R\n" +
+	"delegation\x88\x01\x01B\x16\n" +
+	"\x14_reply_to_message_idB\r\n" +
+	"\v_delegation\"\x13\n" +
 	"\x11ListTopicsRequest\"9\n" +
 	"\x12ListTopicsResponse\x12#\n" +
 	"\x06topics\x18\x01 \x03(\v2\v.chat.TopicR\x06topics\"E\n" +
@@ -1963,7 +2056,7 @@ const file_chat_proto_rawDesc = "" +
 	"\fdisplay_name\x18\x02 \x01(\tR\vdisplayName\"G\n" +
 	"\x12UpdateTopicRequest\x12\x0e\n" +
 	"\x02id\x18\x01 \x01(\tR\x02id\x12!\n" +
-	"\fdisplay_name\x18\x02 \x01(\tR\vdisplayName\"\xbb\x02\n" +
+	"\fdisplay_name\x18\x02 \x01(\tR\vdisplayName\"\x86\x03\n" +
 	"\x12PostMessageRequest\x12\x19\n" +
 	"\btopic_id\x18\x01 \x01(\tR\atopicId\x12\x1b\n" +
 	"\tauthor_id\x18\x02 \x01(\tR\bauthorId\x121\n" +
@@ -1972,14 +2065,22 @@ const file_chat_proto_rawDesc = "" +
 	"\x06source\x18\x04 \x01(\x0e2\x13.chat.MessageSourceR\x06source\x12\x18\n" +
 	"\acontent\x18\x05 \x01(\tR\acontent\x122\n" +
 	"\x13reply_to_message_id\x18\x06 \x01(\tH\x00R\x10replyToMessageId\x88\x01\x01\x12'\n" +
-	"\x0fidempotency_key\x18\a \x01(\tR\x0eidempotencyKeyB\x16\n" +
-	"\x14_reply_to_message_id\"\xc3\x01\n" +
+	"\x0fidempotency_key\x18\a \x01(\tR\x0eidempotencyKey\x12:\n" +
+	"\n" +
+	"delegation\x18\b \x01(\v2\x15.chat.AgentDelegationH\x01R\n" +
+	"delegation\x88\x01\x01B\x16\n" +
+	"\x14_reply_to_message_idB\r\n" +
+	"\v_delegation\"\x8e\x02\n" +
 	"\x17AgentPostMessageRequest\x12\x19\n" +
 	"\btopic_id\x18\x01 \x01(\tR\atopicId\x12\x18\n" +
 	"\acontent\x18\x02 \x01(\tR\acontent\x122\n" +
 	"\x13reply_to_message_id\x18\x03 \x01(\tH\x00R\x10replyToMessageId\x88\x01\x01\x12'\n" +
-	"\x0fidempotency_key\x18\x04 \x01(\tR\x0eidempotencyKeyB\x16\n" +
-	"\x14_reply_to_message_id\"^\n" +
+	"\x0fidempotency_key\x18\x04 \x01(\tR\x0eidempotencyKey\x12:\n" +
+	"\n" +
+	"delegation\x18\x05 \x01(\v2\x15.chat.AgentDelegationH\x01R\n" +
+	"delegation\x88\x01\x01B\x16\n" +
+	"\x14_reply_to_message_idB\r\n" +
+	"\v_delegation\"^\n" +
 	"\x13PostMessageResponse\x12'\n" +
 	"\amessage\x18\x01 \x01(\v2\r.chat.MessageR\amessage\x12\x1e\n" +
 	"\n" +
@@ -2116,103 +2217,107 @@ func file_chat_proto_rawDescGZIP() []byte {
 }
 
 var file_chat_proto_enumTypes = make([]protoimpl.EnumInfo, 2)
-var file_chat_proto_msgTypes = make([]protoimpl.MessageInfo, 31)
+var file_chat_proto_msgTypes = make([]protoimpl.MessageInfo, 32)
 var file_chat_proto_goTypes = []any{
 	(AuthorType)(0),                        // 0: chat.AuthorType
 	(MessageSource)(0),                     // 1: chat.MessageSource
 	(*Topic)(nil),                          // 2: chat.Topic
-	(*Message)(nil),                        // 3: chat.Message
-	(*ListTopicsRequest)(nil),              // 4: chat.ListTopicsRequest
-	(*ListTopicsResponse)(nil),             // 5: chat.ListTopicsResponse
-	(*GetTopicRequest)(nil),                // 6: chat.GetTopicRequest
-	(*CreateTopicRequest)(nil),             // 7: chat.CreateTopicRequest
-	(*UpdateTopicRequest)(nil),             // 8: chat.UpdateTopicRequest
-	(*PostMessageRequest)(nil),             // 9: chat.PostMessageRequest
-	(*AgentPostMessageRequest)(nil),        // 10: chat.AgentPostMessageRequest
-	(*PostMessageResponse)(nil),            // 11: chat.PostMessageResponse
-	(*GetMessageRequest)(nil),              // 12: chat.GetMessageRequest
-	(*HistoryRequest)(nil),                 // 13: chat.HistoryRequest
-	(*HistoryResponse)(nil),                // 14: chat.HistoryResponse
-	(*SubscribeRequest)(nil),               // 15: chat.SubscribeRequest
-	(*DeliveryMessage)(nil),                // 16: chat.DeliveryMessage
-	(*AcknowledgeRequest)(nil),             // 17: chat.AcknowledgeRequest
-	(*AcknowledgeResponse)(nil),            // 18: chat.AcknowledgeResponse
-	(*Participant)(nil),                    // 19: chat.Participant
-	(*GetParticipantRequest)(nil),          // 20: chat.GetParticipantRequest
-	(*BatchGetParticipantsRequest)(nil),    // 21: chat.BatchGetParticipantsRequest
-	(*BatchGetParticipantsResponse)(nil),   // 22: chat.BatchGetParticipantsResponse
-	(*ListTopicParticipantsRequest)(nil),   // 23: chat.ListTopicParticipantsRequest
-	(*ListTopicParticipantsResponse)(nil),  // 24: chat.ListTopicParticipantsResponse
-	(*GetMyParticipantRequest)(nil),        // 25: chat.GetMyParticipantRequest
-	(*RegisterSelfProfileRequest)(nil),     // 26: chat.RegisterSelfProfileRequest
-	(*SyncMyTopicMembershipsRequest)(nil),  // 27: chat.SyncMyTopicMembershipsRequest
-	(*SyncMyTopicMembershipsResponse)(nil), // 28: chat.SyncMyTopicMembershipsResponse
-	(*UploadSelfAvatarRequest)(nil),        // 29: chat.UploadSelfAvatarRequest
-	(*DeleteSelfAvatarRequest)(nil),        // 30: chat.DeleteSelfAvatarRequest
-	nil,                                    // 31: chat.Participant.AliasesEntry
-	nil,                                    // 32: chat.RegisterSelfProfileRequest.AliasesEntry
-	(*timestamppb.Timestamp)(nil),          // 33: google.protobuf.Timestamp
+	(*AgentDelegation)(nil),                // 3: chat.AgentDelegation
+	(*Message)(nil),                        // 4: chat.Message
+	(*ListTopicsRequest)(nil),              // 5: chat.ListTopicsRequest
+	(*ListTopicsResponse)(nil),             // 6: chat.ListTopicsResponse
+	(*GetTopicRequest)(nil),                // 7: chat.GetTopicRequest
+	(*CreateTopicRequest)(nil),             // 8: chat.CreateTopicRequest
+	(*UpdateTopicRequest)(nil),             // 9: chat.UpdateTopicRequest
+	(*PostMessageRequest)(nil),             // 10: chat.PostMessageRequest
+	(*AgentPostMessageRequest)(nil),        // 11: chat.AgentPostMessageRequest
+	(*PostMessageResponse)(nil),            // 12: chat.PostMessageResponse
+	(*GetMessageRequest)(nil),              // 13: chat.GetMessageRequest
+	(*HistoryRequest)(nil),                 // 14: chat.HistoryRequest
+	(*HistoryResponse)(nil),                // 15: chat.HistoryResponse
+	(*SubscribeRequest)(nil),               // 16: chat.SubscribeRequest
+	(*DeliveryMessage)(nil),                // 17: chat.DeliveryMessage
+	(*AcknowledgeRequest)(nil),             // 18: chat.AcknowledgeRequest
+	(*AcknowledgeResponse)(nil),            // 19: chat.AcknowledgeResponse
+	(*Participant)(nil),                    // 20: chat.Participant
+	(*GetParticipantRequest)(nil),          // 21: chat.GetParticipantRequest
+	(*BatchGetParticipantsRequest)(nil),    // 22: chat.BatchGetParticipantsRequest
+	(*BatchGetParticipantsResponse)(nil),   // 23: chat.BatchGetParticipantsResponse
+	(*ListTopicParticipantsRequest)(nil),   // 24: chat.ListTopicParticipantsRequest
+	(*ListTopicParticipantsResponse)(nil),  // 25: chat.ListTopicParticipantsResponse
+	(*GetMyParticipantRequest)(nil),        // 26: chat.GetMyParticipantRequest
+	(*RegisterSelfProfileRequest)(nil),     // 27: chat.RegisterSelfProfileRequest
+	(*SyncMyTopicMembershipsRequest)(nil),  // 28: chat.SyncMyTopicMembershipsRequest
+	(*SyncMyTopicMembershipsResponse)(nil), // 29: chat.SyncMyTopicMembershipsResponse
+	(*UploadSelfAvatarRequest)(nil),        // 30: chat.UploadSelfAvatarRequest
+	(*DeleteSelfAvatarRequest)(nil),        // 31: chat.DeleteSelfAvatarRequest
+	nil,                                    // 32: chat.Participant.AliasesEntry
+	nil,                                    // 33: chat.RegisterSelfProfileRequest.AliasesEntry
+	(*timestamppb.Timestamp)(nil),          // 34: google.protobuf.Timestamp
 }
 var file_chat_proto_depIdxs = []int32{
-	33, // 0: chat.Topic.created_at:type_name -> google.protobuf.Timestamp
+	34, // 0: chat.Topic.created_at:type_name -> google.protobuf.Timestamp
 	0,  // 1: chat.Message.author_type:type_name -> chat.AuthorType
 	1,  // 2: chat.Message.source:type_name -> chat.MessageSource
-	33, // 3: chat.Message.created_at:type_name -> google.protobuf.Timestamp
-	2,  // 4: chat.ListTopicsResponse.topics:type_name -> chat.Topic
-	0,  // 5: chat.PostMessageRequest.author_type:type_name -> chat.AuthorType
-	1,  // 6: chat.PostMessageRequest.source:type_name -> chat.MessageSource
-	3,  // 7: chat.PostMessageResponse.message:type_name -> chat.Message
-	3,  // 8: chat.HistoryResponse.messages:type_name -> chat.Message
-	3,  // 9: chat.DeliveryMessage.message:type_name -> chat.Message
-	0,  // 10: chat.Participant.author_type:type_name -> chat.AuthorType
-	31, // 11: chat.Participant.aliases:type_name -> chat.Participant.AliasesEntry
-	33, // 12: chat.Participant.last_seen_at:type_name -> google.protobuf.Timestamp
-	33, // 13: chat.Participant.created_at:type_name -> google.protobuf.Timestamp
-	33, // 14: chat.Participant.updated_at:type_name -> google.protobuf.Timestamp
-	19, // 15: chat.BatchGetParticipantsResponse.participants:type_name -> chat.Participant
-	19, // 16: chat.ListTopicParticipantsResponse.participants:type_name -> chat.Participant
-	32, // 17: chat.RegisterSelfProfileRequest.aliases:type_name -> chat.RegisterSelfProfileRequest.AliasesEntry
-	4,  // 18: chat.ChatService.ListTopics:input_type -> chat.ListTopicsRequest
-	6,  // 19: chat.ChatService.GetTopic:input_type -> chat.GetTopicRequest
-	7,  // 20: chat.ChatService.CreateTopic:input_type -> chat.CreateTopicRequest
-	8,  // 21: chat.ChatService.UpdateTopic:input_type -> chat.UpdateTopicRequest
-	9,  // 22: chat.ChatService.PostMessage:input_type -> chat.PostMessageRequest
-	10, // 23: chat.ChatService.AgentPostMessage:input_type -> chat.AgentPostMessageRequest
-	12, // 24: chat.ChatService.GetMessage:input_type -> chat.GetMessageRequest
-	13, // 25: chat.ChatService.History:input_type -> chat.HistoryRequest
-	15, // 26: chat.ChatService.Subscribe:input_type -> chat.SubscribeRequest
-	17, // 27: chat.ChatService.Acknowledge:input_type -> chat.AcknowledgeRequest
-	20, // 28: chat.ChatService.GetParticipant:input_type -> chat.GetParticipantRequest
-	21, // 29: chat.ChatService.BatchGetParticipants:input_type -> chat.BatchGetParticipantsRequest
-	23, // 30: chat.ChatService.ListTopicParticipants:input_type -> chat.ListTopicParticipantsRequest
-	25, // 31: chat.ChatService.GetMyParticipant:input_type -> chat.GetMyParticipantRequest
-	26, // 32: chat.ChatService.RegisterSelfProfile:input_type -> chat.RegisterSelfProfileRequest
-	27, // 33: chat.ChatService.SyncMyTopicMemberships:input_type -> chat.SyncMyTopicMembershipsRequest
-	29, // 34: chat.ChatService.UploadSelfAvatar:input_type -> chat.UploadSelfAvatarRequest
-	30, // 35: chat.ChatService.DeleteSelfAvatar:input_type -> chat.DeleteSelfAvatarRequest
-	5,  // 36: chat.ChatService.ListTopics:output_type -> chat.ListTopicsResponse
-	2,  // 37: chat.ChatService.GetTopic:output_type -> chat.Topic
-	2,  // 38: chat.ChatService.CreateTopic:output_type -> chat.Topic
-	2,  // 39: chat.ChatService.UpdateTopic:output_type -> chat.Topic
-	11, // 40: chat.ChatService.PostMessage:output_type -> chat.PostMessageResponse
-	11, // 41: chat.ChatService.AgentPostMessage:output_type -> chat.PostMessageResponse
-	3,  // 42: chat.ChatService.GetMessage:output_type -> chat.Message
-	14, // 43: chat.ChatService.History:output_type -> chat.HistoryResponse
-	16, // 44: chat.ChatService.Subscribe:output_type -> chat.DeliveryMessage
-	18, // 45: chat.ChatService.Acknowledge:output_type -> chat.AcknowledgeResponse
-	19, // 46: chat.ChatService.GetParticipant:output_type -> chat.Participant
-	22, // 47: chat.ChatService.BatchGetParticipants:output_type -> chat.BatchGetParticipantsResponse
-	24, // 48: chat.ChatService.ListTopicParticipants:output_type -> chat.ListTopicParticipantsResponse
-	19, // 49: chat.ChatService.GetMyParticipant:output_type -> chat.Participant
-	19, // 50: chat.ChatService.RegisterSelfProfile:output_type -> chat.Participant
-	28, // 51: chat.ChatService.SyncMyTopicMemberships:output_type -> chat.SyncMyTopicMembershipsResponse
-	19, // 52: chat.ChatService.UploadSelfAvatar:output_type -> chat.Participant
-	19, // 53: chat.ChatService.DeleteSelfAvatar:output_type -> chat.Participant
-	36, // [36:54] is the sub-list for method output_type
-	18, // [18:36] is the sub-list for method input_type
-	18, // [18:18] is the sub-list for extension type_name
-	18, // [18:18] is the sub-list for extension extendee
-	0,  // [0:18] is the sub-list for field type_name
+	34, // 3: chat.Message.created_at:type_name -> google.protobuf.Timestamp
+	3,  // 4: chat.Message.delegation:type_name -> chat.AgentDelegation
+	2,  // 5: chat.ListTopicsResponse.topics:type_name -> chat.Topic
+	0,  // 6: chat.PostMessageRequest.author_type:type_name -> chat.AuthorType
+	1,  // 7: chat.PostMessageRequest.source:type_name -> chat.MessageSource
+	3,  // 8: chat.PostMessageRequest.delegation:type_name -> chat.AgentDelegation
+	3,  // 9: chat.AgentPostMessageRequest.delegation:type_name -> chat.AgentDelegation
+	4,  // 10: chat.PostMessageResponse.message:type_name -> chat.Message
+	4,  // 11: chat.HistoryResponse.messages:type_name -> chat.Message
+	4,  // 12: chat.DeliveryMessage.message:type_name -> chat.Message
+	0,  // 13: chat.Participant.author_type:type_name -> chat.AuthorType
+	32, // 14: chat.Participant.aliases:type_name -> chat.Participant.AliasesEntry
+	34, // 15: chat.Participant.last_seen_at:type_name -> google.protobuf.Timestamp
+	34, // 16: chat.Participant.created_at:type_name -> google.protobuf.Timestamp
+	34, // 17: chat.Participant.updated_at:type_name -> google.protobuf.Timestamp
+	20, // 18: chat.BatchGetParticipantsResponse.participants:type_name -> chat.Participant
+	20, // 19: chat.ListTopicParticipantsResponse.participants:type_name -> chat.Participant
+	33, // 20: chat.RegisterSelfProfileRequest.aliases:type_name -> chat.RegisterSelfProfileRequest.AliasesEntry
+	5,  // 21: chat.ChatService.ListTopics:input_type -> chat.ListTopicsRequest
+	7,  // 22: chat.ChatService.GetTopic:input_type -> chat.GetTopicRequest
+	8,  // 23: chat.ChatService.CreateTopic:input_type -> chat.CreateTopicRequest
+	9,  // 24: chat.ChatService.UpdateTopic:input_type -> chat.UpdateTopicRequest
+	10, // 25: chat.ChatService.PostMessage:input_type -> chat.PostMessageRequest
+	11, // 26: chat.ChatService.AgentPostMessage:input_type -> chat.AgentPostMessageRequest
+	13, // 27: chat.ChatService.GetMessage:input_type -> chat.GetMessageRequest
+	14, // 28: chat.ChatService.History:input_type -> chat.HistoryRequest
+	16, // 29: chat.ChatService.Subscribe:input_type -> chat.SubscribeRequest
+	18, // 30: chat.ChatService.Acknowledge:input_type -> chat.AcknowledgeRequest
+	21, // 31: chat.ChatService.GetParticipant:input_type -> chat.GetParticipantRequest
+	22, // 32: chat.ChatService.BatchGetParticipants:input_type -> chat.BatchGetParticipantsRequest
+	24, // 33: chat.ChatService.ListTopicParticipants:input_type -> chat.ListTopicParticipantsRequest
+	26, // 34: chat.ChatService.GetMyParticipant:input_type -> chat.GetMyParticipantRequest
+	27, // 35: chat.ChatService.RegisterSelfProfile:input_type -> chat.RegisterSelfProfileRequest
+	28, // 36: chat.ChatService.SyncMyTopicMemberships:input_type -> chat.SyncMyTopicMembershipsRequest
+	30, // 37: chat.ChatService.UploadSelfAvatar:input_type -> chat.UploadSelfAvatarRequest
+	31, // 38: chat.ChatService.DeleteSelfAvatar:input_type -> chat.DeleteSelfAvatarRequest
+	6,  // 39: chat.ChatService.ListTopics:output_type -> chat.ListTopicsResponse
+	2,  // 40: chat.ChatService.GetTopic:output_type -> chat.Topic
+	2,  // 41: chat.ChatService.CreateTopic:output_type -> chat.Topic
+	2,  // 42: chat.ChatService.UpdateTopic:output_type -> chat.Topic
+	12, // 43: chat.ChatService.PostMessage:output_type -> chat.PostMessageResponse
+	12, // 44: chat.ChatService.AgentPostMessage:output_type -> chat.PostMessageResponse
+	4,  // 45: chat.ChatService.GetMessage:output_type -> chat.Message
+	15, // 46: chat.ChatService.History:output_type -> chat.HistoryResponse
+	17, // 47: chat.ChatService.Subscribe:output_type -> chat.DeliveryMessage
+	19, // 48: chat.ChatService.Acknowledge:output_type -> chat.AcknowledgeResponse
+	20, // 49: chat.ChatService.GetParticipant:output_type -> chat.Participant
+	23, // 50: chat.ChatService.BatchGetParticipants:output_type -> chat.BatchGetParticipantsResponse
+	25, // 51: chat.ChatService.ListTopicParticipants:output_type -> chat.ListTopicParticipantsResponse
+	20, // 52: chat.ChatService.GetMyParticipant:output_type -> chat.Participant
+	20, // 53: chat.ChatService.RegisterSelfProfile:output_type -> chat.Participant
+	29, // 54: chat.ChatService.SyncMyTopicMemberships:output_type -> chat.SyncMyTopicMembershipsResponse
+	20, // 55: chat.ChatService.UploadSelfAvatar:output_type -> chat.Participant
+	20, // 56: chat.ChatService.DeleteSelfAvatar:output_type -> chat.Participant
+	39, // [39:57] is the sub-list for method output_type
+	21, // [21:39] is the sub-list for method input_type
+	21, // [21:21] is the sub-list for extension type_name
+	21, // [21:21] is the sub-list for extension extendee
+	0,  // [0:21] is the sub-list for field type_name
 }
 
 func init() { file_chat_proto_init() }
@@ -2220,20 +2325,20 @@ func file_chat_proto_init() {
 	if File_chat_proto != nil {
 		return
 	}
-	file_chat_proto_msgTypes[1].OneofWrappers = []any{}
-	file_chat_proto_msgTypes[4].OneofWrappers = []any{
+	file_chat_proto_msgTypes[2].OneofWrappers = []any{}
+	file_chat_proto_msgTypes[5].OneofWrappers = []any{
 		(*GetTopicRequest_Id)(nil),
 		(*GetTopicRequest_Slug)(nil),
 	}
-	file_chat_proto_msgTypes[7].OneofWrappers = []any{}
 	file_chat_proto_msgTypes[8].OneofWrappers = []any{}
+	file_chat_proto_msgTypes[9].OneofWrappers = []any{}
 	type x struct{}
 	out := protoimpl.TypeBuilder{
 		File: protoimpl.DescBuilder{
 			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
 			RawDescriptor: unsafe.Slice(unsafe.StringData(file_chat_proto_rawDesc), len(file_chat_proto_rawDesc)),
 			NumEnums:      2,
-			NumMessages:   31,
+			NumMessages:   32,
 			NumExtensions: 0,
 			NumServices:   1,
 		},
diff --git a/chat.proto b/chat.proto
index 5c0b51a..669136c 100644
--- a/chat.proto
+++ b/chat.proto
@@ -143,6 +143,17 @@ message Topic {
   google.protobuf.Timestamp created_at = 4;
 }
 
+// AgentDelegation is optional machine-readable routing metadata on AGENT
+// messages. Text content remains the human-readable task description;
+// delegation only carries deterministic target + kind. Delegation is NOT
+// human approval and does NOT authorize mutation.
+message AgentDelegation {
+  // Canonical Chat author_id (UUID) of the target AGENT participant.
+  string target_author_id = 1;
+  // Stage 8 kinds: INVESTIGATE.
+  string kind = 2;
+}
+
 message Message {
   string id = 1; // UUID, canonical message id
   int64 sequence = 2; // server-assigned monotonic sequence (ordering + durable cursor)
@@ -155,6 +166,8 @@ message Message {
   string root_message_id = 9; // root of the reply chain (== id for non-replies)
   int32 reply_depth = 10; // 0 for non-replies, parent depth + 1 for replies; hard max 20
   google.protobuf.Timestamp created_at = 11; // original creation time; age = now - created_at
+  // Optional; only set on AGENT messages that intentionally delegate.
+  optional AgentDelegation delegation = 12;
 }
 
 message ListTopicsRequest {}
@@ -190,6 +203,8 @@ message PostMessageRequest {
   // Idempotency key: retrying PostMessage with the same author_id and key
   // returns the original message instead of creating a duplicate.
   string idempotency_key = 7;
+  // Agents must not use this path; Human HTTP PostMessage rejects delegation.
+  optional AgentDelegation delegation = 8;
 }
 
 message AgentPostMessageRequest {
@@ -199,6 +214,9 @@ message AgentPostMessageRequest {
   // Mandatory: retrying with the same key returns the original message
   // (duplicated=true) instead of creating a duplicate.
   string idempotency_key = 4;
+  // Optional machine-readable delegation. Server validates target is an
+  // existing AGENT participant; sender identity comes from auth, not client.
+  optional AgentDelegation delegation = 5;
 }
 
 message PostMessageResponse {