In the generated code, the service registration details show that ClientStream is not set to true.

[reedkuang]

the generate stream server code ClientStream=false.
source file:
service StreamService {
rpc Test(stream StreamRequest) returns (stream StreamResponse);
}

message StreamRequest {
string msg = 1;
}

message StreamResponse {
string msg = 1;
}

generate code
// StreamServiceServer_ServiceDesc descriptor for server.RegisterService.
var StreamServiceServer_ServiceDesc = server.ServiceDesc{
ServiceName: "trpc.demo.stream.StreamService",
HandlerType: ((*StreamServiceService)(nil)),
StreamHandle: stream.NewStreamDispatcher(),
Methods: []server.Method{},
Streams: []server.StreamDesc{
{
StreamName: "/trpc.demo.stream.StreamService/Test",
Handler: StreamServiceService_Test_Handler,
ServerStreams: true,
},
},
}