diff --git a/chat.pb.go b/chat.pb.go
index 3f3d31d..dfd71ef 100644
--- a/chat.pb.go
+++ b/chat.pb.go
@@ -543,6 +543,58 @@ func (x *CreateTopicRequest) GetDisplayName() string {
 	return ""
 }
 
+type UpdateTopicRequest struct {
+	state         protoimpl.MessageState `protogen:"open.v1"`
+	Id            string                 `protobuf:"bytes,1,opt,name=id,proto3" json:"id,omitempty"`                                      // UUID
+	DisplayName   string                 `protobuf:"bytes,2,opt,name=display_name,json=displayName,proto3" json:"display_name,omitempty"` // new display name (required, full replace)
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *UpdateTopicRequest) Reset() {
+	*x = UpdateTopicRequest{}
+	mi := &file_chat_proto_msgTypes[6]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *UpdateTopicRequest) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*UpdateTopicRequest) ProtoMessage() {}
+
+func (x *UpdateTopicRequest) ProtoReflect() protoreflect.Message {
+	mi := &file_chat_proto_msgTypes[6]
+	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 UpdateTopicRequest.ProtoReflect.Descriptor instead.
+func (*UpdateTopicRequest) Descriptor() ([]byte, []int) {
+	return file_chat_proto_rawDescGZIP(), []int{6}
+}
+
+func (x *UpdateTopicRequest) GetId() string {
+	if x != nil {
+		return x.Id
+	}
+	return ""
+}
+
+func (x *UpdateTopicRequest) GetDisplayName() string {
+	if x != nil {
+		return x.DisplayName
+	}
+	return ""
+}
+
 type PostMessageRequest struct {
 	state            protoimpl.MessageState `protogen:"open.v1"`
 	TopicId          string                 `protobuf:"bytes,1,opt,name=topic_id,json=topicId,proto3" json:"topic_id,omitempty"`
@@ -560,7 +612,7 @@ type PostMessageRequest struct {
 
 func (x *PostMessageRequest) Reset() {
 	*x = PostMessageRequest{}
-	mi := &file_chat_proto_msgTypes[6]
+	mi := &file_chat_proto_msgTypes[7]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -572,7 +624,7 @@ func (x *PostMessageRequest) String() string {
 func (*PostMessageRequest) ProtoMessage() {}
 
 func (x *PostMessageRequest) 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 {
@@ -585,7 +637,7 @@ func (x *PostMessageRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use PostMessageRequest.ProtoReflect.Descriptor instead.
 func (*PostMessageRequest) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{6}
+	return file_chat_proto_rawDescGZIP(), []int{7}
 }
 
 func (x *PostMessageRequest) GetTopicId() string {
@@ -647,7 +699,7 @@ type PostMessageResponse struct {
 
 func (x *PostMessageResponse) Reset() {
 	*x = PostMessageResponse{}
-	mi := &file_chat_proto_msgTypes[7]
+	mi := &file_chat_proto_msgTypes[8]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -659,7 +711,7 @@ func (x *PostMessageResponse) String() string {
 func (*PostMessageResponse) ProtoMessage() {}
 
 func (x *PostMessageResponse) 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 {
@@ -672,7 +724,7 @@ func (x *PostMessageResponse) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use PostMessageResponse.ProtoReflect.Descriptor instead.
 func (*PostMessageResponse) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{7}
+	return file_chat_proto_rawDescGZIP(), []int{8}
 }
 
 func (x *PostMessageResponse) GetMessage() *Message {
@@ -698,7 +750,7 @@ type GetMessageRequest struct {
 
 func (x *GetMessageRequest) Reset() {
 	*x = GetMessageRequest{}
-	mi := &file_chat_proto_msgTypes[8]
+	mi := &file_chat_proto_msgTypes[9]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -710,7 +762,7 @@ func (x *GetMessageRequest) String() string {
 func (*GetMessageRequest) ProtoMessage() {}
 
 func (x *GetMessageRequest) 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 {
@@ -723,7 +775,7 @@ func (x *GetMessageRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use GetMessageRequest.ProtoReflect.Descriptor instead.
 func (*GetMessageRequest) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{8}
+	return file_chat_proto_rawDescGZIP(), []int{9}
 }
 
 func (x *GetMessageRequest) GetMessageId() string {
@@ -750,7 +802,7 @@ type HistoryRequest struct {
 
 func (x *HistoryRequest) Reset() {
 	*x = HistoryRequest{}
-	mi := &file_chat_proto_msgTypes[9]
+	mi := &file_chat_proto_msgTypes[10]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -762,7 +814,7 @@ func (x *HistoryRequest) String() string {
 func (*HistoryRequest) ProtoMessage() {}
 
 func (x *HistoryRequest) 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 {
@@ -775,7 +827,7 @@ func (x *HistoryRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use HistoryRequest.ProtoReflect.Descriptor instead.
 func (*HistoryRequest) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{9}
+	return file_chat_proto_rawDescGZIP(), []int{10}
 }
 
 func (x *HistoryRequest) GetTopicId() string {
@@ -817,7 +869,7 @@ type HistoryResponse struct {
 
 func (x *HistoryResponse) Reset() {
 	*x = HistoryResponse{}
-	mi := &file_chat_proto_msgTypes[10]
+	mi := &file_chat_proto_msgTypes[11]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -829,7 +881,7 @@ func (x *HistoryResponse) String() string {
 func (*HistoryResponse) ProtoMessage() {}
 
 func (x *HistoryResponse) 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 {
@@ -842,7 +894,7 @@ func (x *HistoryResponse) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use HistoryResponse.ProtoReflect.Descriptor instead.
 func (*HistoryResponse) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{10}
+	return file_chat_proto_rawDescGZIP(), []int{11}
 }
 
 func (x *HistoryResponse) GetMessages() []*Message {
@@ -869,7 +921,7 @@ type SubscribeRequest struct {
 
 func (x *SubscribeRequest) Reset() {
 	*x = SubscribeRequest{}
-	mi := &file_chat_proto_msgTypes[11]
+	mi := &file_chat_proto_msgTypes[12]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -881,7 +933,7 @@ func (x *SubscribeRequest) String() string {
 func (*SubscribeRequest) ProtoMessage() {}
 
 func (x *SubscribeRequest) 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 {
@@ -894,7 +946,7 @@ func (x *SubscribeRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use SubscribeRequest.ProtoReflect.Descriptor instead.
 func (*SubscribeRequest) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{11}
+	return file_chat_proto_rawDescGZIP(), []int{12}
 }
 
 func (x *SubscribeRequest) GetConsumerId() string {
@@ -922,7 +974,7 @@ type AcknowledgeRequest struct {
 
 func (x *AcknowledgeRequest) Reset() {
 	*x = AcknowledgeRequest{}
-	mi := &file_chat_proto_msgTypes[12]
+	mi := &file_chat_proto_msgTypes[13]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -934,7 +986,7 @@ func (x *AcknowledgeRequest) String() string {
 func (*AcknowledgeRequest) ProtoMessage() {}
 
 func (x *AcknowledgeRequest) 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 {
@@ -947,7 +999,7 @@ func (x *AcknowledgeRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use AcknowledgeRequest.ProtoReflect.Descriptor instead.
 func (*AcknowledgeRequest) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{12}
+	return file_chat_proto_rawDescGZIP(), []int{13}
 }
 
 func (x *AcknowledgeRequest) GetConsumerId() string {
@@ -980,7 +1032,7 @@ type AcknowledgeResponse struct {
 
 func (x *AcknowledgeResponse) Reset() {
 	*x = AcknowledgeResponse{}
-	mi := &file_chat_proto_msgTypes[13]
+	mi := &file_chat_proto_msgTypes[14]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -992,7 +1044,7 @@ func (x *AcknowledgeResponse) String() string {
 func (*AcknowledgeResponse) ProtoMessage() {}
 
 func (x *AcknowledgeResponse) 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 {
@@ -1005,7 +1057,7 @@ func (x *AcknowledgeResponse) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use AcknowledgeResponse.ProtoReflect.Descriptor instead.
 func (*AcknowledgeResponse) Descriptor() ([]byte, []int) {
-	return file_chat_proto_rawDescGZIP(), []int{13}
+	return file_chat_proto_rawDescGZIP(), []int{14}
 }
 
 func (x *AcknowledgeResponse) GetLastAckSequence() int64 {
@@ -1054,6 +1106,9 @@ const file_chat_proto_rawDesc = "" +
 	"\bselector\"K\n" +
 	"\x12CreateTopicRequest\x12\x12\n" +
 	"\x04slug\x18\x01 \x01(\tR\x04slug\x12!\n" +
+	"\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" +
 	"\x12PostMessageRequest\x12\x19\n" +
 	"\btopic_id\x18\x01 \x01(\tR\atopicId\x12\x1b\n" +
@@ -1104,12 +1159,13 @@ const file_chat_proto_rawDesc = "" +
 	"\x12MESSAGE_SOURCE_WEB\x10\x01\x12\x1b\n" +
 	"\x17MESSAGE_SOURCE_TELEGRAM\x10\x02\x12\x18\n" +
 	"\x14MESSAGE_SOURCE_AGENT\x10\x03\x12\x19\n" +
-	"\x15MESSAGE_SOURCE_SYSTEM\x10\x042\xe0\x03\n" +
+	"\x15MESSAGE_SOURCE_SYSTEM\x10\x042\x96\x04\n" +
 	"\vChatService\x12?\n" +
 	"\n" +
 	"ListTopics\x12\x17.chat.ListTopicsRequest\x1a\x18.chat.ListTopicsResponse\x12.\n" +
 	"\bGetTopic\x12\x15.chat.GetTopicRequest\x1a\v.chat.Topic\x124\n" +
-	"\vCreateTopic\x12\x18.chat.CreateTopicRequest\x1a\v.chat.Topic\x12B\n" +
+	"\vCreateTopic\x12\x18.chat.CreateTopicRequest\x1a\v.chat.Topic\x124\n" +
+	"\vUpdateTopic\x12\x18.chat.UpdateTopicRequest\x1a\v.chat.Topic\x12B\n" +
 	"\vPostMessage\x12\x18.chat.PostMessageRequest\x1a\x19.chat.PostMessageResponse\x124\n" +
 	"\n" +
 	"GetMessage\x12\x17.chat.GetMessageRequest\x1a\r.chat.Message\x126\n" +
@@ -1130,7 +1186,7 @@ func file_chat_proto_rawDescGZIP() []byte {
 }
 
 var file_chat_proto_enumTypes = make([]protoimpl.EnumInfo, 2)
-var file_chat_proto_msgTypes = make([]protoimpl.MessageInfo, 14)
+var file_chat_proto_msgTypes = make([]protoimpl.MessageInfo, 15)
 var file_chat_proto_goTypes = []any{
 	(AuthorType)(0),               // 0: chat.AuthorType
 	(MessageSource)(0),            // 1: chat.MessageSource
@@ -1140,21 +1196,22 @@ var file_chat_proto_goTypes = []any{
 	(*ListTopicsResponse)(nil),    // 5: chat.ListTopicsResponse
 	(*GetTopicRequest)(nil),       // 6: chat.GetTopicRequest
 	(*CreateTopicRequest)(nil),    // 7: chat.CreateTopicRequest
-	(*PostMessageRequest)(nil),    // 8: chat.PostMessageRequest
-	(*PostMessageResponse)(nil),   // 9: chat.PostMessageResponse
-	(*GetMessageRequest)(nil),     // 10: chat.GetMessageRequest
-	(*HistoryRequest)(nil),        // 11: chat.HistoryRequest
-	(*HistoryResponse)(nil),       // 12: chat.HistoryResponse
-	(*SubscribeRequest)(nil),      // 13: chat.SubscribeRequest
-	(*AcknowledgeRequest)(nil),    // 14: chat.AcknowledgeRequest
-	(*AcknowledgeResponse)(nil),   // 15: chat.AcknowledgeResponse
-	(*timestamppb.Timestamp)(nil), // 16: google.protobuf.Timestamp
+	(*UpdateTopicRequest)(nil),    // 8: chat.UpdateTopicRequest
+	(*PostMessageRequest)(nil),    // 9: chat.PostMessageRequest
+	(*PostMessageResponse)(nil),   // 10: chat.PostMessageResponse
+	(*GetMessageRequest)(nil),     // 11: chat.GetMessageRequest
+	(*HistoryRequest)(nil),        // 12: chat.HistoryRequest
+	(*HistoryResponse)(nil),       // 13: chat.HistoryResponse
+	(*SubscribeRequest)(nil),      // 14: chat.SubscribeRequest
+	(*AcknowledgeRequest)(nil),    // 15: chat.AcknowledgeRequest
+	(*AcknowledgeResponse)(nil),   // 16: chat.AcknowledgeResponse
+	(*timestamppb.Timestamp)(nil), // 17: google.protobuf.Timestamp
 }
 var file_chat_proto_depIdxs = []int32{
-	16, // 0: chat.Topic.created_at:type_name -> google.protobuf.Timestamp
+	17, // 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
-	16, // 3: chat.Message.created_at:type_name -> google.protobuf.Timestamp
+	17, // 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
@@ -1163,21 +1220,23 @@ var file_chat_proto_depIdxs = []int32{
 	4,  // 9: chat.ChatService.ListTopics:input_type -> chat.ListTopicsRequest
 	6,  // 10: chat.ChatService.GetTopic:input_type -> chat.GetTopicRequest
 	7,  // 11: chat.ChatService.CreateTopic:input_type -> chat.CreateTopicRequest
-	8,  // 12: chat.ChatService.PostMessage:input_type -> chat.PostMessageRequest
-	10, // 13: chat.ChatService.GetMessage:input_type -> chat.GetMessageRequest
-	11, // 14: chat.ChatService.History:input_type -> chat.HistoryRequest
-	13, // 15: chat.ChatService.Subscribe:input_type -> chat.SubscribeRequest
-	14, // 16: chat.ChatService.Acknowledge:input_type -> chat.AcknowledgeRequest
-	5,  // 17: chat.ChatService.ListTopics:output_type -> chat.ListTopicsResponse
-	2,  // 18: chat.ChatService.GetTopic:output_type -> chat.Topic
-	2,  // 19: chat.ChatService.CreateTopic:output_type -> chat.Topic
-	9,  // 20: chat.ChatService.PostMessage:output_type -> chat.PostMessageResponse
-	3,  // 21: chat.ChatService.GetMessage:output_type -> chat.Message
-	12, // 22: chat.ChatService.History:output_type -> chat.HistoryResponse
-	3,  // 23: chat.ChatService.Subscribe:output_type -> chat.Message
-	15, // 24: chat.ChatService.Acknowledge:output_type -> chat.AcknowledgeResponse
-	17, // [17:25] is the sub-list for method output_type
-	9,  // [9:17] is the sub-list for method input_type
+	8,  // 12: chat.ChatService.UpdateTopic:input_type -> chat.UpdateTopicRequest
+	9,  // 13: chat.ChatService.PostMessage:input_type -> chat.PostMessageRequest
+	11, // 14: chat.ChatService.GetMessage:input_type -> chat.GetMessageRequest
+	12, // 15: chat.ChatService.History:input_type -> chat.HistoryRequest
+	14, // 16: chat.ChatService.Subscribe:input_type -> chat.SubscribeRequest
+	15, // 17: chat.ChatService.Acknowledge:input_type -> chat.AcknowledgeRequest
+	5,  // 18: chat.ChatService.ListTopics:output_type -> chat.ListTopicsResponse
+	2,  // 19: chat.ChatService.GetTopic:output_type -> chat.Topic
+	2,  // 20: chat.ChatService.CreateTopic:output_type -> chat.Topic
+	2,  // 21: chat.ChatService.UpdateTopic:output_type -> chat.Topic
+	10, // 22: chat.ChatService.PostMessage:output_type -> chat.PostMessageResponse
+	3,  // 23: chat.ChatService.GetMessage:output_type -> chat.Message
+	13, // 24: chat.ChatService.History:output_type -> chat.HistoryResponse
+	3,  // 25: chat.ChatService.Subscribe:output_type -> chat.Message
+	16, // 26: chat.ChatService.Acknowledge:output_type -> chat.AcknowledgeResponse
+	18, // [18:27] is the sub-list for method output_type
+	9,  // [9:18] is the sub-list for method input_type
 	9,  // [9:9] is the sub-list for extension type_name
 	9,  // [9:9] is the sub-list for extension extendee
 	0,  // [0:9] is the sub-list for field type_name
@@ -1193,14 +1252,14 @@ func file_chat_proto_init() {
 		(*GetTopicRequest_Id)(nil),
 		(*GetTopicRequest_Slug)(nil),
 	}
-	file_chat_proto_msgTypes[6].OneofWrappers = []any{}
+	file_chat_proto_msgTypes[7].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:   14,
+			NumMessages:   15,
 			NumExtensions: 0,
 			NumServices:   1,
 		},
diff --git a/chat.proto b/chat.proto
index cf42254..a3b14b9 100644
--- a/chat.proto
+++ b/chat.proto
@@ -19,6 +19,11 @@ service ChatService {
   // CreateTopic creates a new topic. Slug must be unique.
   rpc CreateTopic(CreateTopicRequest) returns (Topic);
 
+  // UpdateTopic renames a topic (display_name). The slug is a stable
+  // identifier and cannot be changed. Topics are persistent in the MVP:
+  // there is no delete API.
+  rpc UpdateTopic(UpdateTopicRequest) returns (Topic);
+
   // PostMessage appends a message to a topic. Repeated calls with the same
   // (author_id, idempotency_key) must not create a second message; the
   // original message is returned with duplicated=true instead.
@@ -102,6 +107,11 @@ message CreateTopicRequest {
   string display_name = 2;
 }
 
+message UpdateTopicRequest {
+  string id = 1; // UUID
+  string display_name = 2; // new display name (required, full replace)
+}
+
 message PostMessageRequest {
   string topic_id = 1;
   string author_id = 2;
diff --git a/chat_grpc.pb.go b/chat_grpc.pb.go
index 7c2634e..2c9f706 100644
--- a/chat_grpc.pb.go
+++ b/chat_grpc.pb.go
@@ -22,6 +22,7 @@ const (
 	ChatService_ListTopics_FullMethodName  = "/chat.ChatService/ListTopics"
 	ChatService_GetTopic_FullMethodName    = "/chat.ChatService/GetTopic"
 	ChatService_CreateTopic_FullMethodName = "/chat.ChatService/CreateTopic"
+	ChatService_UpdateTopic_FullMethodName = "/chat.ChatService/UpdateTopic"
 	ChatService_PostMessage_FullMethodName = "/chat.ChatService/PostMessage"
 	ChatService_GetMessage_FullMethodName  = "/chat.ChatService/GetMessage"
 	ChatService_History_FullMethodName     = "/chat.ChatService/History"
@@ -43,6 +44,10 @@ type ChatServiceClient interface {
 	GetTopic(ctx context.Context, in *GetTopicRequest, opts ...grpc.CallOption) (*Topic, error)
 	// CreateTopic creates a new topic. Slug must be unique.
 	CreateTopic(ctx context.Context, in *CreateTopicRequest, opts ...grpc.CallOption) (*Topic, error)
+	// UpdateTopic renames a topic (display_name). The slug is a stable
+	// identifier and cannot be changed. Topics are persistent in the MVP:
+	// there is no delete API.
+	UpdateTopic(ctx context.Context, in *UpdateTopicRequest, opts ...grpc.CallOption) (*Topic, error)
 	// PostMessage appends a message to a topic. Repeated calls with the same
 	// (author_id, idempotency_key) must not create a second message; the
 	// original message is returned with duplicated=true instead.
@@ -100,6 +105,16 @@ func (c *chatServiceClient) CreateTopic(ctx context.Context, in *CreateTopicRequ
 	return out, nil
 }
 
+func (c *chatServiceClient) UpdateTopic(ctx context.Context, in *UpdateTopicRequest, opts ...grpc.CallOption) (*Topic, error) {
+	cOpts := append([]grpc.CallOption{grpc.StaticMethod()}, opts...)
+	out := new(Topic)
+	err := c.cc.Invoke(ctx, ChatService_UpdateTopic_FullMethodName, in, out, cOpts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
 func (c *chatServiceClient) PostMessage(ctx context.Context, in *PostMessageRequest, opts ...grpc.CallOption) (*PostMessageResponse, error) {
 	cOpts := append([]grpc.CallOption{grpc.StaticMethod()}, opts...)
 	out := new(PostMessageResponse)
@@ -173,6 +188,10 @@ type ChatServiceServer interface {
 	GetTopic(context.Context, *GetTopicRequest) (*Topic, error)
 	// CreateTopic creates a new topic. Slug must be unique.
 	CreateTopic(context.Context, *CreateTopicRequest) (*Topic, error)
+	// UpdateTopic renames a topic (display_name). The slug is a stable
+	// identifier and cannot be changed. Topics are persistent in the MVP:
+	// there is no delete API.
+	UpdateTopic(context.Context, *UpdateTopicRequest) (*Topic, error)
 	// PostMessage appends a message to a topic. Repeated calls with the same
 	// (author_id, idempotency_key) must not create a second message; the
 	// original message is returned with duplicated=true instead.
@@ -209,6 +228,9 @@ func (UnimplementedChatServiceServer) GetTopic(context.Context, *GetTopicRequest
 func (UnimplementedChatServiceServer) CreateTopic(context.Context, *CreateTopicRequest) (*Topic, error) {
 	return nil, status.Error(codes.Unimplemented, "method CreateTopic not implemented")
 }
+func (UnimplementedChatServiceServer) UpdateTopic(context.Context, *UpdateTopicRequest) (*Topic, error) {
+	return nil, status.Error(codes.Unimplemented, "method UpdateTopic not implemented")
+}
 func (UnimplementedChatServiceServer) PostMessage(context.Context, *PostMessageRequest) (*PostMessageResponse, error) {
 	return nil, status.Error(codes.Unimplemented, "method PostMessage not implemented")
 }
@@ -299,6 +321,24 @@ func _ChatService_CreateTopic_Handler(srv interface{}, ctx context.Context, dec
 	return interceptor(ctx, in, info, handler)
 }
 
+func _ChatService_UpdateTopic_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(UpdateTopicRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(ChatServiceServer).UpdateTopic(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: ChatService_UpdateTopic_FullMethodName,
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(ChatServiceServer).UpdateTopic(ctx, req.(*UpdateTopicRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
 func _ChatService_PostMessage_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
 	in := new(PostMessageRequest)
 	if err := dec(in); err != nil {
@@ -401,6 +441,10 @@ var ChatService_ServiceDesc = grpc.ServiceDesc{
 			MethodName: "CreateTopic",
 			Handler:    _ChatService_CreateTopic_Handler,
 		},
+		{
+			MethodName: "UpdateTopic",
+			Handler:    _ChatService_UpdateTopic_Handler,
+		},
 		{
 			MethodName: "PostMessage",
 			Handler:    _ChatService_PostMessage_Handler,