diff --git a/examples/echo/echo-client/Main.hs b/examples/echo/echo-client/Main.hs
index e2e0c2a..fc71a54 100644
--- a/examples/echo/echo-client/Main.hs
+++ b/examples/echo/echo-client/Main.hs
@@ -1,21 +1,53 @@
-{-# LANGUAGE LambdaCase                      #-}
-{-# LANGUAGE OverloadedStrings               #-}
+{-# LANGUAGE DeriveGeneric     #-}
+{-# LANGUAGE LambdaCase        #-}
+{-# LANGUAGE OverloadedStrings #-}
 {-# OPTIONS_GHC -fno-warn-missing-signatures #-}
 {-# OPTIONS_GHC -fno-warn-unused-binds       #-}
 
 import           Control.Monad
+import qualified Data.ByteString.Lazy                      as BL
+import           Data.Protobuf.Wire.Class
+import qualified Data.Text                                 as T
+import           Data.Word
+import           GHC.Generics                              (Generic)
 import           Network.GRPC.LowLevel
-import           Network.GRPC.LowLevel.Call
 import qualified Network.GRPC.LowLevel.Client.Unregistered as U
-import           System.Environment
 
 echoMethod = MethodName "/echo.Echo/DoEcho"
 
 _unregistered c = U.clientRequest c echoMethod 1 "hi" mempty
 
-main = withGRPC $ \g ->
+regMain = withGRPC $ \g ->
   withClient g (ClientConfig "localhost" 50051 []) $ \c -> do
-  rm <- clientRegisterMethod c echoMethod Normal
+  rm <- clientRegisterMethodNormal c echoMethod
   replicateM_ 100000 $ clientRequest c rm 5 "hi" mempty >>= \case
     Left e -> error $ "Got client error: " ++ show e
-    _      -> return ()
+    Right r
+      | rspBody r == "hi" -> return ()
+      | otherwise -> error $ "Got unexpected payload: " ++ show r
+
+-- NB: If you change these, make sure to change them in the server as well.
+-- TODO: Put these in a common location (or just hack around it until CG is working)
+data EchoRequest = EchoRequest {message :: T.Text} deriving (Show, Eq, Ord, Generic)
+instance Message EchoRequest
+data AddRequest = AddRequest {addX :: Word32, addY :: Word32} deriving (Show, Eq, Ord, Generic)
+instance Message AddRequest
+data AddResponse = AddResponse {answer :: Word32} deriving (Show, Eq, Ord, Generic)
+instance Message AddResponse
+
+-- TODO: Create Network.GRPC.HighLevel.Client w/ request variants
+
+highlevelMain = withGRPC $ \g ->
+    withClient g (ClientConfig "localhost" 50051 []) $ \c -> do
+    rm <- clientRegisterMethodNormal c echoMethod
+    let pay = EchoRequest "hi"
+        enc = BL.toStrict . toLazyByteString $ pay
+    replicateM_ 1 $ clientRequest c rm 5 enc mempty >>= \case
+      Left e  -> error $ "Got client error: " ++ show e
+      Right r -> case fromByteString (rspBody r) of
+        Left e -> error $ "Got decoding error: " ++ show e
+        Right dec
+          | dec == pay -> return ()
+          | otherwise -> error $ "Got unexpected payload: " ++ show dec
+
+main = highlevelMain
diff --git a/examples/echo/echo-cpp/echo-client.cc b/examples/echo/echo-cpp/echo-client.cc
index 13ad30d..cda410e 100644
--- a/examples/echo/echo-cpp/echo-client.cc
+++ b/examples/echo/echo-cpp/echo-client.cc
@@ -6,12 +6,10 @@
 #include "echo.grpc.pb.h"
 
 using namespace std;
-
+using namespace echo;
 using grpc::Channel;
 using grpc::ClientContext;
 using grpc::Status;
-using echo::EchoRequest;
-using echo::Echo;
 
 class EchoClient {
 public:
@@ -32,7 +30,29 @@ private:
   unique_ptr<Echo::Stub> stub_;
 };
 
+class AddClient {
+public:
+  AddClient(shared_ptr<Channel> chan) : stub_(Add::NewStub(chan)) {}
+
+  AddResponse DoAdd(const uint32_t x, const uint32_t y){
+    AddRequest msg;
+    msg.set_addx(x);
+    msg.set_addy(y);
+
+    AddResponse resp;
+
+    ClientContext ctx;
+
+    stub_->DoAdd(&ctx, msg, &resp);
+
+    return resp;
+  }
+private:
+  unique_ptr<Add::Stub> stub_;
+};
+
 int main(){
+  /*
   EchoClient client(grpc::CreateChannel("localhost:50051",
                                         grpc::InsecureChannelCredentials()));
   string msg("hi");
@@ -43,6 +63,11 @@ int main(){
       return 1;
     }
   }
+*/
 
+  AddClient client (grpc::CreateChannel("localhost:50051",
+                                        grpc::InsecureChannelCredentials()));
+  AddResponse answer = client.DoAdd(1,2);
+  cout<<"Got answer: "<<answer.answer()<<endl;
   return 0;
 }
diff --git a/examples/echo/echo-cpp/echo.grpc.pb.cc b/examples/echo/echo-cpp/echo.grpc.pb.cc
index cc65070..a9f1236 100644
--- a/examples/echo/echo-cpp/echo.grpc.pb.cc
+++ b/examples/echo/echo-cpp/echo.grpc.pb.cc
@@ -37,6 +37,7 @@ Echo::Stub::Stub(const std::shared_ptr< ::grpc::ChannelInterface>& channel)
 }
 
 Echo::Service::Service() {
+  (void)Echo_method_names;
   AddMethod(new ::grpc::RpcServiceMethod(
       Echo_method_names[0],
       ::grpc::RpcMethod::NORMAL_RPC,
@@ -55,5 +56,46 @@ Echo::Service::~Service() {
 }
 
 
+static const char* Add_method_names[] = {
+  "/echo.Add/DoAdd",
+};
+
+std::unique_ptr< Add::Stub> Add::NewStub(const std::shared_ptr< ::grpc::ChannelInterface>& channel, const ::grpc::StubOptions& options) {
+  std::unique_ptr< Add::Stub> stub(new Add::Stub(channel));
+  return stub;
+}
+
+Add::Stub::Stub(const std::shared_ptr< ::grpc::ChannelInterface>& channel)
+  : channel_(channel), rpcmethod_DoAdd_(Add_method_names[0], ::grpc::RpcMethod::NORMAL_RPC, channel)
+  {}
+
+::grpc::Status Add::Stub::DoAdd(::grpc::ClientContext* context, const ::echo::AddRequest& request, ::echo::AddResponse* response) {
+  return ::grpc::BlockingUnaryCall(channel_.get(), rpcmethod_DoAdd_, context, request, response);
+}
+
+::grpc::ClientAsyncResponseReader< ::echo::AddResponse>* Add::Stub::AsyncDoAddRaw(::grpc::ClientContext* context, const ::echo::AddRequest& request, ::grpc::CompletionQueue* cq) {
+  return new ::grpc::ClientAsyncResponseReader< ::echo::AddResponse>(channel_.get(), cq, rpcmethod_DoAdd_, context, request);
+}
+
+Add::Service::Service() {
+  (void)Add_method_names;
+  AddMethod(new ::grpc::RpcServiceMethod(
+      Add_method_names[0],
+      ::grpc::RpcMethod::NORMAL_RPC,
+      new ::grpc::RpcMethodHandler< Add::Service, ::echo::AddRequest, ::echo::AddResponse>(
+          std::mem_fn(&Add::Service::DoAdd), this)));
+}
+
+Add::Service::~Service() {
+}
+
+::grpc::Status Add::Service::DoAdd(::grpc::ServerContext* context, const ::echo::AddRequest* request, ::echo::AddResponse* response) {
+  (void) context;
+  (void) request;
+  (void) response;
+  return ::grpc::Status(::grpc::StatusCode::UNIMPLEMENTED, "");
+}
+
+
 }  // namespace echo
 
diff --git a/examples/echo/echo-cpp/echo.grpc.pb.h b/examples/echo/echo-cpp/echo.grpc.pb.h
index df1c128..c22a4a8 100644
--- a/examples/echo/echo-cpp/echo.grpc.pb.h
+++ b/examples/echo/echo-cpp/echo.grpc.pb.h
@@ -17,6 +17,7 @@
 
 namespace grpc {
 class CompletionQueue;
+class Channel;
 class RpcService;
 class ServerCompletionQueue;
 class ServerContext;
@@ -60,7 +61,7 @@ class Echo GRPC_FINAL {
   template <class BaseClass>
   class WithAsyncMethod_DoEcho : public BaseClass {
    private:
-    void BaseClassMustBeDerivedFromService(Service *service) {}
+    void BaseClassMustBeDerivedFromService(const Service *service) {}
    public:
     WithAsyncMethod_DoEcho() {
       ::grpc::Service::MarkMethodAsync(0);
@@ -81,7 +82,7 @@ class Echo GRPC_FINAL {
   template <class BaseClass>
   class WithGenericMethod_DoEcho : public BaseClass {
    private:
-    void BaseClassMustBeDerivedFromService(Service *service) {}
+    void BaseClassMustBeDerivedFromService(const Service *service) {}
    public:
     WithGenericMethod_DoEcho() {
       ::grpc::Service::MarkMethodGeneric(0);
@@ -97,6 +98,79 @@ class Echo GRPC_FINAL {
   };
 };
 
+class Add GRPC_FINAL {
+ public:
+  class StubInterface {
+   public:
+    virtual ~StubInterface() {}
+    virtual ::grpc::Status DoAdd(::grpc::ClientContext* context, const ::echo::AddRequest& request, ::echo::AddResponse* response) = 0;
+    std::unique_ptr< ::grpc::ClientAsyncResponseReaderInterface< ::echo::AddResponse>> AsyncDoAdd(::grpc::ClientContext* context, const ::echo::AddRequest& request, ::grpc::CompletionQueue* cq) {
+      return std::unique_ptr< ::grpc::ClientAsyncResponseReaderInterface< ::echo::AddResponse>>(AsyncDoAddRaw(context, request, cq));
+    }
+  private:
+    virtual ::grpc::ClientAsyncResponseReaderInterface< ::echo::AddResponse>* AsyncDoAddRaw(::grpc::ClientContext* context, const ::echo::AddRequest& request, ::grpc::CompletionQueue* cq) = 0;
+  };
+  class Stub GRPC_FINAL : public StubInterface {
+   public:
+    Stub(const std::shared_ptr< ::grpc::ChannelInterface>& channel);
+    ::grpc::Status DoAdd(::grpc::ClientContext* context, const ::echo::AddRequest& request, ::echo::AddResponse* response) GRPC_OVERRIDE;
+    std::unique_ptr< ::grpc::ClientAsyncResponseReader< ::echo::AddResponse>> AsyncDoAdd(::grpc::ClientContext* context, const ::echo::AddRequest& request, ::grpc::CompletionQueue* cq) {
+      return std::unique_ptr< ::grpc::ClientAsyncResponseReader< ::echo::AddResponse>>(AsyncDoAddRaw(context, request, cq));
+    }
+
+   private:
+    std::shared_ptr< ::grpc::ChannelInterface> channel_;
+    ::grpc::ClientAsyncResponseReader< ::echo::AddResponse>* AsyncDoAddRaw(::grpc::ClientContext* context, const ::echo::AddRequest& request, ::grpc::CompletionQueue* cq) GRPC_OVERRIDE;
+    const ::grpc::RpcMethod rpcmethod_DoAdd_;
+  };
+  static std::unique_ptr<Stub> NewStub(const std::shared_ptr< ::grpc::ChannelInterface>& channel, const ::grpc::StubOptions& options = ::grpc::StubOptions());
+
+  class Service : public ::grpc::Service {
+   public:
+    Service();
+    virtual ~Service();
+    virtual ::grpc::Status DoAdd(::grpc::ServerContext* context, const ::echo::AddRequest* request, ::echo::AddResponse* response);
+  };
+  template <class BaseClass>
+  class WithAsyncMethod_DoAdd : public BaseClass {
+   private:
+    void BaseClassMustBeDerivedFromService(const Service *service) {}
+   public:
+    WithAsyncMethod_DoAdd() {
+      ::grpc::Service::MarkMethodAsync(0);
+    }
+    ~WithAsyncMethod_DoAdd() GRPC_OVERRIDE {
+      BaseClassMustBeDerivedFromService(this);
+    }
+    // disable synchronous version of this method
+    ::grpc::Status DoAdd(::grpc::ServerContext* context, const ::echo::AddRequest* request, ::echo::AddResponse* response) GRPC_FINAL GRPC_OVERRIDE {
+      abort();
+      return ::grpc::Status(::grpc::StatusCode::UNIMPLEMENTED, "");
+    }
+    void RequestDoAdd(::grpc::ServerContext* context, ::echo::AddRequest* request, ::grpc::ServerAsyncResponseWriter< ::echo::AddResponse>* response, ::grpc::CompletionQueue* new_call_cq, ::grpc::ServerCompletionQueue* notification_cq, void *tag) {
+      ::grpc::Service::RequestAsyncUnary(0, context, request, response, new_call_cq, notification_cq, tag);
+    }
+  };
+  typedef WithAsyncMethod_DoAdd<Service > AsyncService;
+  template <class BaseClass>
+  class WithGenericMethod_DoAdd : public BaseClass {
+   private:
+    void BaseClassMustBeDerivedFromService(const Service *service) {}
+   public:
+    WithGenericMethod_DoAdd() {
+      ::grpc::Service::MarkMethodGeneric(0);
+    }
+    ~WithGenericMethod_DoAdd() GRPC_OVERRIDE {
+      BaseClassMustBeDerivedFromService(this);
+    }
+    // disable synchronous version of this method
+    ::grpc::Status DoAdd(::grpc::ServerContext* context, const ::echo::AddRequest* request, ::echo::AddResponse* response) GRPC_FINAL GRPC_OVERRIDE {
+      abort();
+      return ::grpc::Status(::grpc::StatusCode::UNIMPLEMENTED, "");
+    }
+  };
+};
+
 }  // namespace echo
 
 
diff --git a/examples/echo/echo-cpp/echo.pb.cc b/examples/echo/echo-cpp/echo.pb.cc
index c68cac1..9ecfa3b 100644
--- a/examples/echo/echo-cpp/echo.pb.cc
+++ b/examples/echo/echo-cpp/echo.pb.cc
@@ -24,6 +24,12 @@ namespace {
 const ::google::protobuf::Descriptor* EchoRequest_descriptor_ = NULL;
 const ::google::protobuf::internal::GeneratedMessageReflection*
   EchoRequest_reflection_ = NULL;
+const ::google::protobuf::Descriptor* AddRequest_descriptor_ = NULL;
+const ::google::protobuf::internal::GeneratedMessageReflection*
+  AddRequest_reflection_ = NULL;
+const ::google::protobuf::Descriptor* AddResponse_descriptor_ = NULL;
+const ::google::protobuf::internal::GeneratedMessageReflection*
+  AddResponse_reflection_ = NULL;
 
 }  // namespace
 
@@ -49,6 +55,37 @@ void protobuf_AssignDesc_echo_2eproto() {
       sizeof(EchoRequest),
       GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET(EchoRequest, _internal_metadata_),
       GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET(EchoRequest, _is_default_instance_));
+  AddRequest_descriptor_ = file->message_type(1);
+  static const int AddRequest_offsets_[2] = {
+    GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET(AddRequest, addx_),
+    GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET(AddRequest, addy_),
+  };
+  AddRequest_reflection_ =
+    ::google::protobuf::internal::GeneratedMessageReflection::NewGeneratedMessageReflection(
+      AddRequest_descriptor_,
+      AddRequest::default_instance_,
+      AddRequest_offsets_,
+      -1,
+      -1,
+      -1,
+      sizeof(AddRequest),
+      GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET(AddRequest, _internal_metadata_),
+      GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET(AddRequest, _is_default_instance_));
+  AddResponse_descriptor_ = file->message_type(2);
+  static const int AddResponse_offsets_[1] = {
+    GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET(AddResponse, answer_),
+  };
+  AddResponse_reflection_ =
+    ::google::protobuf::internal::GeneratedMessageReflection::NewGeneratedMessageReflection(
+      AddResponse_descriptor_,
+      AddResponse::default_instance_,
+      AddResponse_offsets_,
+      -1,
+      -1,
+      -1,
+      sizeof(AddResponse),
+      GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET(AddResponse, _internal_metadata_),
+      GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET(AddResponse, _is_default_instance_));
 }
 
 namespace {
@@ -63,6 +100,10 @@ void protobuf_RegisterTypes(const ::std::string&) {
   protobuf_AssignDescriptorsOnce();
   ::google::protobuf::MessageFactory::InternalRegisterGeneratedMessage(
       EchoRequest_descriptor_, &EchoRequest::default_instance());
+  ::google::protobuf::MessageFactory::InternalRegisterGeneratedMessage(
+      AddRequest_descriptor_, &AddRequest::default_instance());
+  ::google::protobuf::MessageFactory::InternalRegisterGeneratedMessage(
+      AddResponse_descriptor_, &AddResponse::default_instance());
 }
 
 }  // namespace
@@ -70,6 +111,10 @@ void protobuf_RegisterTypes(const ::std::string&) {
 void protobuf_ShutdownFile_echo_2eproto() {
   delete EchoRequest::default_instance_;
   delete EchoRequest_reflection_;
+  delete AddRequest::default_instance_;
+  delete AddRequest_reflection_;
+  delete AddResponse::default_instance_;
+  delete AddResponse_reflection_;
 }
 
 void protobuf_AddDesc_echo_2eproto() {
@@ -80,12 +125,20 @@ void protobuf_AddDesc_echo_2eproto() {
 
   ::google::protobuf::DescriptorPool::InternalAddGeneratedFile(
     "\n\necho.proto\022\004echo\"\036\n\013EchoRequest\022\017\n\007mes"
-    "sage\030\001 \001(\t28\n\004Echo\0220\n\006DoEcho\022\021.echo.Echo"
-    "Request\032\021.echo.EchoRequest\"\000b\006proto3", 116);
+    "sage\030\001 \001(\t\"(\n\nAddRequest\022\014\n\004addX\030\001 \001(\007\022\014"
+    "\n\004addY\030\002 \001(\007\"\035\n\013AddResponse\022\016\n\006answer\030\001 "
+    "\001(\00728\n\004Echo\0220\n\006DoEcho\022\021.echo.EchoRequest"
+    "\032\021.echo.EchoRequest\"\00025\n\003Add\022.\n\005DoAdd\022\020."
+    "echo.AddRequest\032\021.echo.AddResponse\"\000b\006pr"
+    "oto3", 244);
   ::google::protobuf::MessageFactory::InternalRegisterGeneratedFile(
     "echo.proto", &protobuf_RegisterTypes);
   EchoRequest::default_instance_ = new EchoRequest();
+  AddRequest::default_instance_ = new AddRequest();
+  AddResponse::default_instance_ = new AddResponse();
   EchoRequest::default_instance_->InitAsDefaultInstance();
+  AddRequest::default_instance_->InitAsDefaultInstance();
+  AddResponse::default_instance_->InitAsDefaultInstance();
   ::google::protobuf::internal::OnShutdown(&protobuf_ShutdownFile_echo_2eproto);
 }
 
@@ -377,6 +430,516 @@ void EchoRequest::clear_message() {
 
 #endif  // PROTOBUF_INLINE_NOT_IN_HEADERS
 
+// ===================================================================
+
+#if !defined(_MSC_VER) || _MSC_VER >= 1900
+const int AddRequest::kAddXFieldNumber;
+const int AddRequest::kAddYFieldNumber;
+#endif  // !defined(_MSC_VER) || _MSC_VER >= 1900
+
+AddRequest::AddRequest()
+  : ::google::protobuf::Message(), _internal_metadata_(NULL) {
+  SharedCtor();
+  // @@protoc_insertion_point(constructor:echo.AddRequest)
+}
+
+void AddRequest::InitAsDefaultInstance() {
+  _is_default_instance_ = true;
+}
+
+AddRequest::AddRequest(const AddRequest& from)
+  : ::google::protobuf::Message(),
+    _internal_metadata_(NULL) {
+  SharedCtor();
+  MergeFrom(from);
+  // @@protoc_insertion_point(copy_constructor:echo.AddRequest)
+}
+
+void AddRequest::SharedCtor() {
+    _is_default_instance_ = false;
+  _cached_size_ = 0;
+  addx_ = 0u;
+  addy_ = 0u;
+}
+
+AddRequest::~AddRequest() {
+  // @@protoc_insertion_point(destructor:echo.AddRequest)
+  SharedDtor();
+}
+
+void AddRequest::SharedDtor() {
+  if (this != default_instance_) {
+  }
+}
+
+void AddRequest::SetCachedSize(int size) const {
+  GOOGLE_SAFE_CONCURRENT_WRITES_BEGIN();
+  _cached_size_ = size;
+  GOOGLE_SAFE_CONCURRENT_WRITES_END();
+}
+const ::google::protobuf::Descriptor* AddRequest::descriptor() {
+  protobuf_AssignDescriptorsOnce();
+  return AddRequest_descriptor_;
+}
+
+const AddRequest& AddRequest::default_instance() {
+  if (default_instance_ == NULL) protobuf_AddDesc_echo_2eproto();
+  return *default_instance_;
+}
+
+AddRequest* AddRequest::default_instance_ = NULL;
+
+AddRequest* AddRequest::New(::google::protobuf::Arena* arena) const {
+  AddRequest* n = new AddRequest;
+  if (arena != NULL) {
+    arena->Own(n);
+  }
+  return n;
+}
+
+void AddRequest::Clear() {
+#define ZR_HELPER_(f) reinterpret_cast<char*>(\
+  &reinterpret_cast<AddRequest*>(16)->f)
+
+#define ZR_(first, last) do {\
+  ::memset(&first, 0,\
+           ZR_HELPER_(last) - ZR_HELPER_(first) + sizeof(last));\
+} while (0)
+
+  ZR_(addx_, addy_);
+
+#undef ZR_HELPER_
+#undef ZR_
+
+}
+
+bool AddRequest::MergePartialFromCodedStream(
+    ::google::protobuf::io::CodedInputStream* input) {
+#define DO_(EXPRESSION) if (!(EXPRESSION)) goto failure
+  ::google::protobuf::uint32 tag;
+  // @@protoc_insertion_point(parse_start:echo.AddRequest)
+  for (;;) {
+    ::std::pair< ::google::protobuf::uint32, bool> p = input->ReadTagWithCutoff(127);
+    tag = p.first;
+    if (!p.second) goto handle_unusual;
+    switch (::google::protobuf::internal::WireFormatLite::GetTagFieldNumber(tag)) {
+      // optional fixed32 addX = 1;
+      case 1: {
+        if (tag == 13) {
+          DO_((::google::protobuf::internal::WireFormatLite::ReadPrimitive<
+                   ::google::protobuf::uint32, ::google::protobuf::internal::WireFormatLite::TYPE_FIXED32>(
+                 input, &addx_)));
+
+        } else {
+          goto handle_unusual;
+        }
+        if (input->ExpectTag(21)) goto parse_addY;
+        break;
+      }
+
+      // optional fixed32 addY = 2;
+      case 2: {
+        if (tag == 21) {
+         parse_addY:
+          DO_((::google::protobuf::internal::WireFormatLite::ReadPrimitive<
+                   ::google::protobuf::uint32, ::google::protobuf::internal::WireFormatLite::TYPE_FIXED32>(
+                 input, &addy_)));
+
+        } else {
+          goto handle_unusual;
+        }
+        if (input->ExpectAtEnd()) goto success;
+        break;
+      }
+
+      default: {
+      handle_unusual:
+        if (tag == 0 ||
+            ::google::protobuf::internal::WireFormatLite::GetTagWireType(tag) ==
+            ::google::protobuf::internal::WireFormatLite::WIRETYPE_END_GROUP) {
+          goto success;
+        }
+        DO_(::google::protobuf::internal::WireFormatLite::SkipField(input, tag));
+        break;
+      }
+    }
+  }
+success:
+  // @@protoc_insertion_point(parse_success:echo.AddRequest)
+  return true;
+failure:
+  // @@protoc_insertion_point(parse_failure:echo.AddRequest)
+  return false;
+#undef DO_
+}
+
+void AddRequest::SerializeWithCachedSizes(
+    ::google::protobuf::io::CodedOutputStream* output) const {
+  // @@protoc_insertion_point(serialize_start:echo.AddRequest)
+  // optional fixed32 addX = 1;
+  if (this->addx() != 0) {
+    ::google::protobuf::internal::WireFormatLite::WriteFixed32(1, this->addx(), output);
+  }
+
+  // optional fixed32 addY = 2;
+  if (this->addy() != 0) {
+    ::google::protobuf::internal::WireFormatLite::WriteFixed32(2, this->addy(), output);
+  }
+
+  // @@protoc_insertion_point(serialize_end:echo.AddRequest)
+}
+
+::google::protobuf::uint8* AddRequest::SerializeWithCachedSizesToArray(
+    ::google::protobuf::uint8* target) const {
+  // @@protoc_insertion_point(serialize_to_array_start:echo.AddRequest)
+  // optional fixed32 addX = 1;
+  if (this->addx() != 0) {
+    target = ::google::protobuf::internal::WireFormatLite::WriteFixed32ToArray(1, this->addx(), target);
+  }
+
+  // optional fixed32 addY = 2;
+  if (this->addy() != 0) {
+    target = ::google::protobuf::internal::WireFormatLite::WriteFixed32ToArray(2, this->addy(), target);
+  }
+
+  // @@protoc_insertion_point(serialize_to_array_end:echo.AddRequest)
+  return target;
+}
+
+int AddRequest::ByteSize() const {
+  int total_size = 0;
+
+  // optional fixed32 addX = 1;
+  if (this->addx() != 0) {
+    total_size += 1 + 4;
+  }
+
+  // optional fixed32 addY = 2;
+  if (this->addy() != 0) {
+    total_size += 1 + 4;
+  }
+
+  GOOGLE_SAFE_CONCURRENT_WRITES_BEGIN();
+  _cached_size_ = total_size;
+  GOOGLE_SAFE_CONCURRENT_WRITES_END();
+  return total_size;
+}
+
+void AddRequest::MergeFrom(const ::google::protobuf::Message& from) {
+  if (GOOGLE_PREDICT_FALSE(&from == this)) MergeFromFail(__LINE__);
+  const AddRequest* source = 
+      ::google::protobuf::internal::DynamicCastToGenerated<const AddRequest>(
+          &from);
+  if (source == NULL) {
+    ::google::protobuf::internal::ReflectionOps::Merge(from, this);
+  } else {
+    MergeFrom(*source);
+  }
+}
+
+void AddRequest::MergeFrom(const AddRequest& from) {
+  if (GOOGLE_PREDICT_FALSE(&from == this)) MergeFromFail(__LINE__);
+  if (from.addx() != 0) {
+    set_addx(from.addx());
+  }
+  if (from.addy() != 0) {
+    set_addy(from.addy());
+  }
+}
+
+void AddRequest::CopyFrom(const ::google::protobuf::Message& from) {
+  if (&from == this) return;
+  Clear();
+  MergeFrom(from);
+}
+
+void AddRequest::CopyFrom(const AddRequest& from) {
+  if (&from == this) return;
+  Clear();
+  MergeFrom(from);
+}
+
+bool AddRequest::IsInitialized() const {
+
+  return true;
+}
+
+void AddRequest::Swap(AddRequest* other) {
+  if (other == this) return;
+  InternalSwap(other);
+}
+void AddRequest::InternalSwap(AddRequest* other) {
+  std::swap(addx_, other->addx_);
+  std::swap(addy_, other->addy_);
+  _internal_metadata_.Swap(&other->_internal_metadata_);
+  std::swap(_cached_size_, other->_cached_size_);
+}
+
+::google::protobuf::Metadata AddRequest::GetMetadata() const {
+  protobuf_AssignDescriptorsOnce();
+  ::google::protobuf::Metadata metadata;
+  metadata.descriptor = AddRequest_descriptor_;
+  metadata.reflection = AddRequest_reflection_;
+  return metadata;
+}
+
+#if PROTOBUF_INLINE_NOT_IN_HEADERS
+// AddRequest
+
+// optional fixed32 addX = 1;
+void AddRequest::clear_addx() {
+  addx_ = 0u;
+}
+ ::google::protobuf::uint32 AddRequest::addx() const {
+  // @@protoc_insertion_point(field_get:echo.AddRequest.addX)
+  return addx_;
+}
+ void AddRequest::set_addx(::google::protobuf::uint32 value) {
+  
+  addx_ = value;
+  // @@protoc_insertion_point(field_set:echo.AddRequest.addX)
+}
+
+// optional fixed32 addY = 2;
+void AddRequest::clear_addy() {
+  addy_ = 0u;
+}
+ ::google::protobuf::uint32 AddRequest::addy() const {
+  // @@protoc_insertion_point(field_get:echo.AddRequest.addY)
+  return addy_;
+}
+ void AddRequest::set_addy(::google::protobuf::uint32 value) {
+  
+  addy_ = value;
+  // @@protoc_insertion_point(field_set:echo.AddRequest.addY)
+}
+
+#endif  // PROTOBUF_INLINE_NOT_IN_HEADERS
+
+// ===================================================================
+
+#if !defined(_MSC_VER) || _MSC_VER >= 1900
+const int AddResponse::kAnswerFieldNumber;
+#endif  // !defined(_MSC_VER) || _MSC_VER >= 1900
+
+AddResponse::AddResponse()
+  : ::google::protobuf::Message(), _internal_metadata_(NULL) {
+  SharedCtor();
+  // @@protoc_insertion_point(constructor:echo.AddResponse)
+}
+
+void AddResponse::InitAsDefaultInstance() {
+  _is_default_instance_ = true;
+}
+
+AddResponse::AddResponse(const AddResponse& from)
+  : ::google::protobuf::Message(),
+    _internal_metadata_(NULL) {
+  SharedCtor();
+  MergeFrom(from);
+  // @@protoc_insertion_point(copy_constructor:echo.AddResponse)
+}
+
+void AddResponse::SharedCtor() {
+    _is_default_instance_ = false;
+  _cached_size_ = 0;
+  answer_ = 0u;
+}
+
+AddResponse::~AddResponse() {
+  // @@protoc_insertion_point(destructor:echo.AddResponse)
+  SharedDtor();
+}
+
+void AddResponse::SharedDtor() {
+  if (this != default_instance_) {
+  }
+}
+
+void AddResponse::SetCachedSize(int size) const {
+  GOOGLE_SAFE_CONCURRENT_WRITES_BEGIN();
+  _cached_size_ = size;
+  GOOGLE_SAFE_CONCURRENT_WRITES_END();
+}
+const ::google::protobuf::Descriptor* AddResponse::descriptor() {
+  protobuf_AssignDescriptorsOnce();
+  return AddResponse_descriptor_;
+}
+
+const AddResponse& AddResponse::default_instance() {
+  if (default_instance_ == NULL) protobuf_AddDesc_echo_2eproto();
+  return *default_instance_;
+}
+
+AddResponse* AddResponse::default_instance_ = NULL;
+
+AddResponse* AddResponse::New(::google::protobuf::Arena* arena) const {
+  AddResponse* n = new AddResponse;
+  if (arena != NULL) {
+    arena->Own(n);
+  }
+  return n;
+}
+
+void AddResponse::Clear() {
+  answer_ = 0u;
+}
+
+bool AddResponse::MergePartialFromCodedStream(
+    ::google::protobuf::io::CodedInputStream* input) {
+#define DO_(EXPRESSION) if (!(EXPRESSION)) goto failure
+  ::google::protobuf::uint32 tag;
+  // @@protoc_insertion_point(parse_start:echo.AddResponse)
+  for (;;) {
+    ::std::pair< ::google::protobuf::uint32, bool> p = input->ReadTagWithCutoff(127);
+    tag = p.first;
+    if (!p.second) goto handle_unusual;
+    switch (::google::protobuf::internal::WireFormatLite::GetTagFieldNumber(tag)) {
+      // optional fixed32 answer = 1;
+      case 1: {
+        if (tag == 13) {
+          DO_((::google::protobuf::internal::WireFormatLite::ReadPrimitive<
+                   ::google::protobuf::uint32, ::google::protobuf::internal::WireFormatLite::TYPE_FIXED32>(
+                 input, &answer_)));
+
+        } else {
+          goto handle_unusual;
+        }
+        if (input->ExpectAtEnd()) goto success;
+        break;
+      }
+
+      default: {
+      handle_unusual:
+        if (tag == 0 ||
+            ::google::protobuf::internal::WireFormatLite::GetTagWireType(tag) ==
+            ::google::protobuf::internal::WireFormatLite::WIRETYPE_END_GROUP) {
+          goto success;
+        }
+        DO_(::google::protobuf::internal::WireFormatLite::SkipField(input, tag));
+        break;
+      }
+    }
+  }
+success:
+  // @@protoc_insertion_point(parse_success:echo.AddResponse)
+  return true;
+failure:
+  // @@protoc_insertion_point(parse_failure:echo.AddResponse)
+  return false;
+#undef DO_
+}
+
+void AddResponse::SerializeWithCachedSizes(
+    ::google::protobuf::io::CodedOutputStream* output) const {
+  // @@protoc_insertion_point(serialize_start:echo.AddResponse)
+  // optional fixed32 answer = 1;
+  if (this->answer() != 0) {
+    ::google::protobuf::internal::WireFormatLite::WriteFixed32(1, this->answer(), output);
+  }
+
+  // @@protoc_insertion_point(serialize_end:echo.AddResponse)
+}
+
+::google::protobuf::uint8* AddResponse::SerializeWithCachedSizesToArray(
+    ::google::protobuf::uint8* target) const {
+  // @@protoc_insertion_point(serialize_to_array_start:echo.AddResponse)
+  // optional fixed32 answer = 1;
+  if (this->answer() != 0) {
+    target = ::google::protobuf::internal::WireFormatLite::WriteFixed32ToArray(1, this->answer(), target);
+  }
+
+  // @@protoc_insertion_point(serialize_to_array_end:echo.AddResponse)
+  return target;
+}
+
+int AddResponse::ByteSize() const {
+  int total_size = 0;
+
+  // optional fixed32 answer = 1;
+  if (this->answer() != 0) {
+    total_size += 1 + 4;
+  }
+
+  GOOGLE_SAFE_CONCURRENT_WRITES_BEGIN();
+  _cached_size_ = total_size;
+  GOOGLE_SAFE_CONCURRENT_WRITES_END();
+  return total_size;
+}
+
+void AddResponse::MergeFrom(const ::google::protobuf::Message& from) {
+  if (GOOGLE_PREDICT_FALSE(&from == this)) MergeFromFail(__LINE__);
+  const AddResponse* source = 
+      ::google::protobuf::internal::DynamicCastToGenerated<const AddResponse>(
+          &from);
+  if (source == NULL) {
+    ::google::protobuf::internal::ReflectionOps::Merge(from, this);
+  } else {
+    MergeFrom(*source);
+  }
+}
+
+void AddResponse::MergeFrom(const AddResponse& from) {
+  if (GOOGLE_PREDICT_FALSE(&from == this)) MergeFromFail(__LINE__);
+  if (from.answer() != 0) {
+    set_answer(from.answer());
+  }
+}
+
+void AddResponse::CopyFrom(const ::google::protobuf::Message& from) {
+  if (&from == this) return;
+  Clear();
+  MergeFrom(from);
+}
+
+void AddResponse::CopyFrom(const AddResponse& from) {
+  if (&from == this) return;
+  Clear();
+  MergeFrom(from);
+}
+
+bool AddResponse::IsInitialized() const {
+
+  return true;
+}
+
+void AddResponse::Swap(AddResponse* other) {
+  if (other == this) return;
+  InternalSwap(other);
+}
+void AddResponse::InternalSwap(AddResponse* other) {
+  std::swap(answer_, other->answer_);
+  _internal_metadata_.Swap(&other->_internal_metadata_);
+  std::swap(_cached_size_, other->_cached_size_);
+}
+
+::google::protobuf::Metadata AddResponse::GetMetadata() const {
+  protobuf_AssignDescriptorsOnce();
+  ::google::protobuf::Metadata metadata;
+  metadata.descriptor = AddResponse_descriptor_;
+  metadata.reflection = AddResponse_reflection_;
+  return metadata;
+}
+
+#if PROTOBUF_INLINE_NOT_IN_HEADERS
+// AddResponse
+
+// optional fixed32 answer = 1;
+void AddResponse::clear_answer() {
+  answer_ = 0u;
+}
+ ::google::protobuf::uint32 AddResponse::answer() const {
+  // @@protoc_insertion_point(field_get:echo.AddResponse.answer)
+  return answer_;
+}
+ void AddResponse::set_answer(::google::protobuf::uint32 value) {
+  
+  answer_ = value;
+  // @@protoc_insertion_point(field_set:echo.AddResponse.answer)
+}
+
+#endif  // PROTOBUF_INLINE_NOT_IN_HEADERS
+
 // @@protoc_insertion_point(namespace_scope)
 
 }  // namespace echo
diff --git a/examples/echo/echo-cpp/echo.pb.h b/examples/echo/echo-cpp/echo.pb.h
index 089f94a..d430892 100644
--- a/examples/echo/echo-cpp/echo.pb.h
+++ b/examples/echo/echo-cpp/echo.pb.h
@@ -36,6 +36,8 @@ void protobuf_AddDesc_echo_2eproto();
 void protobuf_AssignDesc_echo_2eproto();
 void protobuf_ShutdownFile_echo_2eproto();
 
+class AddRequest;
+class AddResponse;
 class EchoRequest;
 
 // ===================================================================
@@ -121,6 +123,169 @@ class EchoRequest : public ::google::protobuf::Message {
   void InitAsDefaultInstance();
   static EchoRequest* default_instance_;
 };
+// -------------------------------------------------------------------
+
+class AddRequest : public ::google::protobuf::Message {
+ public:
+  AddRequest();
+  virtual ~AddRequest();
+
+  AddRequest(const AddRequest& from);
+
+  inline AddRequest& operator=(const AddRequest& from) {
+    CopyFrom(from);
+    return *this;
+  }
+
+  static const ::google::protobuf::Descriptor* descriptor();
+  static const AddRequest& default_instance();
+
+  void Swap(AddRequest* other);
+
+  // implements Message ----------------------------------------------
+
+  inline AddRequest* New() const { return New(NULL); }
+
+  AddRequest* New(::google::protobuf::Arena* arena) const;
+  void CopyFrom(const ::google::protobuf::Message& from);
+  void MergeFrom(const ::google::protobuf::Message& from);
+  void CopyFrom(const AddRequest& from);
+  void MergeFrom(const AddRequest& from);
+  void Clear();
+  bool IsInitialized() const;
+
+  int ByteSize() const;
+  bool MergePartialFromCodedStream(
+      ::google::protobuf::io::CodedInputStream* input);
+  void SerializeWithCachedSizes(
+      ::google::protobuf::io::CodedOutputStream* output) const;
+  ::google::protobuf::uint8* SerializeWithCachedSizesToArray(::google::protobuf::uint8* output) const;
+  int GetCachedSize() const { return _cached_size_; }
+  private:
+  void SharedCtor();
+  void SharedDtor();
+  void SetCachedSize(int size) const;
+  void InternalSwap(AddRequest* other);
+  private:
+  inline ::google::protobuf::Arena* GetArenaNoVirtual() const {
+    return _internal_metadata_.arena();
+  }
+  inline void* MaybeArenaPtr() const {
+    return _internal_metadata_.raw_arena_ptr();
+  }
+  public:
+
+  ::google::protobuf::Metadata GetMetadata() const;
+
+  // nested types ----------------------------------------------------
+
+  // accessors -------------------------------------------------------
+
+  // optional fixed32 addX = 1;
+  void clear_addx();
+  static const int kAddXFieldNumber = 1;
+  ::google::protobuf::uint32 addx() const;
+  void set_addx(::google::protobuf::uint32 value);
+
+  // optional fixed32 addY = 2;
+  void clear_addy();
+  static const int kAddYFieldNumber = 2;
+  ::google::protobuf::uint32 addy() const;
+  void set_addy(::google::protobuf::uint32 value);
+
+  // @@protoc_insertion_point(class_scope:echo.AddRequest)
+ private:
+
+  ::google::protobuf::internal::InternalMetadataWithArena _internal_metadata_;
+  bool _is_default_instance_;
+  ::google::protobuf::uint32 addx_;
+  ::google::protobuf::uint32 addy_;
+  mutable int _cached_size_;
+  friend void  protobuf_AddDesc_echo_2eproto();
+  friend void protobuf_AssignDesc_echo_2eproto();
+  friend void protobuf_ShutdownFile_echo_2eproto();
+
+  void InitAsDefaultInstance();
+  static AddRequest* default_instance_;
+};
+// -------------------------------------------------------------------
+
+class AddResponse : public ::google::protobuf::Message {
+ public:
+  AddResponse();
+  virtual ~AddResponse();
+
+  AddResponse(const AddResponse& from);
+
+  inline AddResponse& operator=(const AddResponse& from) {
+    CopyFrom(from);
+    return *this;
+  }
+
+  static const ::google::protobuf::Descriptor* descriptor();
+  static const AddResponse& default_instance();
+
+  void Swap(AddResponse* other);
+
+  // implements Message ----------------------------------------------
+
+  inline AddResponse* New() const { return New(NULL); }
+
+  AddResponse* New(::google::protobuf::Arena* arena) const;
+  void CopyFrom(const ::google::protobuf::Message& from);
+  void MergeFrom(const ::google::protobuf::Message& from);
+  void CopyFrom(const AddResponse& from);
+  void MergeFrom(const AddResponse& from);
+  void Clear();
+  bool IsInitialized() const;
+
+  int ByteSize() const;
+  bool MergePartialFromCodedStream(
+      ::google::protobuf::io::CodedInputStream* input);
+  void SerializeWithCachedSizes(
+      ::google::protobuf::io::CodedOutputStream* output) const;
+  ::google::protobuf::uint8* SerializeWithCachedSizesToArray(::google::protobuf::uint8* output) const;
+  int GetCachedSize() const { return _cached_size_; }
+  private:
+  void SharedCtor();
+  void SharedDtor();
+  void SetCachedSize(int size) const;
+  void InternalSwap(AddResponse* other);
+  private:
+  inline ::google::protobuf::Arena* GetArenaNoVirtual() const {
+    return _internal_metadata_.arena();
+  }
+  inline void* MaybeArenaPtr() const {
+    return _internal_metadata_.raw_arena_ptr();
+  }
+  public:
+
+  ::google::protobuf::Metadata GetMetadata() const;
+
+  // nested types ----------------------------------------------------
+
+  // accessors -------------------------------------------------------
+
+  // optional fixed32 answer = 1;
+  void clear_answer();
+  static const int kAnswerFieldNumber = 1;
+  ::google::protobuf::uint32 answer() const;
+  void set_answer(::google::protobuf::uint32 value);
+
+  // @@protoc_insertion_point(class_scope:echo.AddResponse)
+ private:
+
+  ::google::protobuf::internal::InternalMetadataWithArena _internal_metadata_;
+  bool _is_default_instance_;
+  ::google::protobuf::uint32 answer_;
+  mutable int _cached_size_;
+  friend void  protobuf_AddDesc_echo_2eproto();
+  friend void protobuf_AssignDesc_echo_2eproto();
+  friend void protobuf_ShutdownFile_echo_2eproto();
+
+  void InitAsDefaultInstance();
+  static AddResponse* default_instance_;
+};
 // ===================================================================
 
 
@@ -172,7 +337,61 @@ inline void EchoRequest::set_allocated_message(::std::string* message) {
   // @@protoc_insertion_point(field_set_allocated:echo.EchoRequest.message)
 }
 
+// -------------------------------------------------------------------
+
+// AddRequest
+
+// optional fixed32 addX = 1;
+inline void AddRequest::clear_addx() {
+  addx_ = 0u;
+}
+inline ::google::protobuf::uint32 AddRequest::addx() const {
+  // @@protoc_insertion_point(field_get:echo.AddRequest.addX)
+  return addx_;
+}
+inline void AddRequest::set_addx(::google::protobuf::uint32 value) {
+  
+  addx_ = value;
+  // @@protoc_insertion_point(field_set:echo.AddRequest.addX)
+}
+
+// optional fixed32 addY = 2;
+inline void AddRequest::clear_addy() {
+  addy_ = 0u;
+}
+inline ::google::protobuf::uint32 AddRequest::addy() const {
+  // @@protoc_insertion_point(field_get:echo.AddRequest.addY)
+  return addy_;
+}
+inline void AddRequest::set_addy(::google::protobuf::uint32 value) {
+  
+  addy_ = value;
+  // @@protoc_insertion_point(field_set:echo.AddRequest.addY)
+}
+
+// -------------------------------------------------------------------
+
+// AddResponse
+
+// optional fixed32 answer = 1;
+inline void AddResponse::clear_answer() {
+  answer_ = 0u;
+}
+inline ::google::protobuf::uint32 AddResponse::answer() const {
+  // @@protoc_insertion_point(field_get:echo.AddResponse.answer)
+  return answer_;
+}
+inline void AddResponse::set_answer(::google::protobuf::uint32 value) {
+  
+  answer_ = value;
+  // @@protoc_insertion_point(field_set:echo.AddResponse.answer)
+}
+
 #endif  // !PROTOBUF_INLINE_NOT_IN_HEADERS
+// -------------------------------------------------------------------
+
+// -------------------------------------------------------------------
+
 
 // @@protoc_insertion_point(namespace_scope)
 
diff --git a/examples/echo/echo-server/Main.hs b/examples/echo/echo-server/Main.hs
index 8c97856..2d0070e 100644
--- a/examples/echo/echo-server/Main.hs
+++ b/examples/echo/echo-server/Main.hs
@@ -1,7 +1,8 @@
-{-# LANGUAGE DataKinds                       #-}
-{-# LANGUAGE OverloadedLists                 #-}
-{-# LANGUAGE OverloadedStrings               #-}
-{-# LANGUAGE RecordWildCards                 #-}
+{-# LANGUAGE DataKinds         #-}
+{-# LANGUAGE DeriveGeneric     #-}
+{-# LANGUAGE OverloadedLists   #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards   #-}
 {-# OPTIONS_GHC -fno-warn-missing-signatures #-}
 {-# OPTIONS_GHC -fno-warn-unused-binds       #-}
 
@@ -9,10 +10,14 @@ import           Control.Concurrent
 import           Control.Concurrent.Async
 import           Control.Monad
 import           Data.ByteString                           (ByteString)
+import           Data.Protobuf.Wire.Class
+import qualified Data.Text                                 as T
+import           Data.Word
+import           GHC.Generics                              (Generic)
+import           Network.GRPC.HighLevel.Server
 import           Network.GRPC.LowLevel
-import           Network.GRPC.LowLevel.Call
+import qualified Network.GRPC.LowLevel.Call.Unregistered   as U
 import qualified Network.GRPC.LowLevel.Server.Unregistered as U
-import qualified Network.GRPC.LowLevel.Call.Unregistered as U
 
 serverMeta :: MetadataMap
 serverMeta = [("test_meta", "test_meta_value")]
@@ -27,7 +32,7 @@ handler U.ServerCall{..} reqBody = do
 
 unregMain :: IO ()
 unregMain = withGRPC $ \grpc -> do
-  withServer grpc (ServerConfig "localhost" 50051 [] []) $ \server -> forever $ do
+  withServer grpc defConfig $ \server -> forever $ do
     result <- U.serverHandleNormalCall server serverMeta handler
     case result of
       Left x -> putStrLn $ "handle call result error: " ++ show x
@@ -35,8 +40,8 @@ unregMain = withGRPC $ \grpc -> do
 
 regMain :: IO ()
 regMain = withGRPC $ \grpc -> do
-  let methods = [(MethodName "/echo.Echo/DoEcho", Normal)]
-  withServer grpc (ServerConfig "localhost" 50051 methods []) $ \server ->
+  let ms = [(MethodName "/echo.Echo/DoEcho")]
+  withServer grpc (defConfig {methodsToRegisterNormal = ms}) $ \server ->
     forever $ do
       let method = head (normalMethods server)
       result <- serverHandleNormalCall server method serverMeta $
@@ -63,13 +68,56 @@ regLoop server method = forever $ do
 regMainThreaded :: IO ()
 regMainThreaded = do
   withGRPC $ \grpc -> do
-    let methods = [(MethodName "/echo.Echo/DoEcho", Normal)]
-    withServer grpc (ServerConfig "localhost" 50051 methods []) $ \server -> do
+    let ms = [(MethodName "/echo.Echo/DoEcho")]
+    withServer grpc (defConfig {methodsToRegisterNormal = ms}) $ \server -> do
       let method = head (normalMethods server)
       tids <- replicateM 7 $ async $ do tputStrLn "starting handler"
                                         regLoop server method
       waitAnyCancel tids
       tputStrLn "finishing"
 
+-- NB: If you change these, make sure to change them in the client as well.
+-- TODO: Put these in a common location (or just hack around it until CG is working)
+data EchoRequest = EchoRequest {message :: T.Text} deriving (Show, Eq, Ord, Generic)
+instance Message EchoRequest
+data AddRequest = AddRequest {addX :: Word32, addY :: Word32} deriving (Show, Eq, Ord, Generic)
+instance Message AddRequest
+data AddResponse = AddResponse {answer :: Word32} deriving (Show, Eq, Ord, Generic)
+instance Message AddResponse
+
+highlevelMain :: IO ()
+highlevelMain =
+  serverLoop defaultOptions{optNormalHandlers = [echoHandler, addHandler]}
+  where echoHandler =
+          UnaryHandler "/echo.Echo/DoEcho" $
+            \_c body m -> do
+              tputStrLn $ "UnaryHandler for DoEcho hit, body=" ++ show body
+              return ( body :: EchoRequest
+                     , m
+                     , StatusOk
+                     , StatusDetails ""
+                     )
+        addHandler =
+          --TODO: I can't get this one to execute. Is the generated method
+          --name different?
+
+          -- static const char* Add_method_names[] = {
+          --   "/echo.Add/DoAdd",
+          -- };
+
+          UnaryHandler "/echo.Add/DoAdd" $
+            \_c b m -> do
+              tputStrLn $ "UnaryHandler for DoAdd hit, b=" ++ show b
+              print (addX b)
+              print (addY b)
+              return ( AddResponse $ addX b + addY b
+                     , m
+                     , StatusOk
+                     , StatusDetails ""
+                     )
+
 main :: IO ()
-main = regMainThreaded
+main = highlevelMain
+
+defConfig :: ServerConfig
+defConfig = ServerConfig "localhost" 50051 [] [] [] [] []
diff --git a/examples/echo/echo.proto b/examples/echo/echo.proto
index ed192c7..5ac72fe 100644
--- a/examples/echo/echo.proto
+++ b/examples/echo/echo.proto
@@ -9,3 +9,16 @@ service Echo {
 message EchoRequest {
   string message = 1;
 }
+
+message AddRequest {
+  fixed32 addX = 1;
+  fixed32 addY = 2;
+}
+
+message AddResponse {
+  fixed32 answer = 1;
+}
+
+service Add {
+  rpc DoAdd (AddRequest) returns (AddResponse) {}
+}
diff --git a/grpc-haskell.cabal b/grpc-haskell.cabal
index 5da6c4f..f29fb32 100644
--- a/grpc-haskell.cabal
+++ b/grpc-haskell.cabal
@@ -33,6 +33,8 @@ library
     , managed >= 1.0.5 && < 1.1
     , pipes ==4.1.*
     , transformers
+    , proto3-wire
+    , protobuf-wire
 
     , async
     , tasty >= 0.11 && <0.12
@@ -63,6 +65,8 @@ library
     Network.GRPC.LowLevel.Call
     Network.GRPC.LowLevel.Call.Unregistered
     Network.GRPC.LowLevel.Client
+    Network.GRPC.HighLevel
+    Network.GRPC.HighLevel.Server
   extra-libraries:
     grpc
   includes:
@@ -86,11 +90,14 @@ library
 executable echo-server
   if flag(with-examples)
     build-depends:
-      base ==4.8.*
-      , bytestring == 0.10.*
-      , grpc-haskell
-      , containers ==0.5.*
+        base ==4.8.*
       , async
+      , bytestring == 0.10.*
+      , containers ==0.5.*
+      , grpc-haskell
+      , proto3-wire
+      , protobuf-wire
+      , text
   else
     buildable: False
   default-language: Haskell2010
@@ -101,10 +108,14 @@ executable echo-server
 executable echo-client
   if flag(with-examples)
     build-depends:
-      base ==4.8.*
+        base ==4.8.*
+      , async
       , bytestring == 0.10.*
-      , grpc-haskell
       , containers ==0.5.*
+      , grpc-haskell
+      , proto3-wire
+      , protobuf-wire
+      , text
   else
     buildable: False
   default-language: Haskell2010
diff --git a/src/Network/GRPC/HighLevel.hs b/src/Network/GRPC/HighLevel.hs
new file mode 100644
index 0000000..a230a3d
--- /dev/null
+++ b/src/Network/GRPC/HighLevel.hs
@@ -0,0 +1,10 @@
+module Network.GRPC.HighLevel (
+-- * Server
+Handler(..)
+, ServerOptions(..)
+, defaultOptions
+, serverLoop
+)
+ where
+
+import Network.GRPC.HighLevel.Server
diff --git a/src/Network/GRPC/HighLevel/Server.hs b/src/Network/GRPC/HighLevel/Server.hs
new file mode 100644
index 0000000..0b9b1cd
--- /dev/null
+++ b/src/Network/GRPC/HighLevel/Server.hs
@@ -0,0 +1,223 @@
+{-# LANGUAGE DataKinds         #-}
+{-# LANGUAGE GADTs             #-}
+{-# LANGUAGE LambdaCase        #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RankNTypes        #-}
+{-# LANGUAGE RecordWildCards   #-}
+
+module Network.GRPC.HighLevel.Server where
+
+import           Control.Concurrent.Async
+import           Control.Monad
+import           Data.ByteString                           (ByteString)
+import qualified Data.ByteString.Lazy                      as BL
+import           Data.Protobuf.Wire.Class
+import           Network.GRPC.LowLevel
+import qualified Network.GRPC.LowLevel.Call.Unregistered   as U
+import           Network.GRPC.LowLevel.GRPC
+import qualified Network.GRPC.LowLevel.Server.Unregistered as U
+
+type ServerHandler' a b =
+  forall c .
+  ServerCall c
+  -> a
+  -> MetadataMap
+  -> IO (b, MetadataMap, StatusCode, StatusDetails)
+
+convertServerHandler :: (Message a, Message b)
+                     => ServerHandler' a b
+                     -> ServerHandler
+convertServerHandler f c bs m = case fromByteString bs of
+  Left{}  -> error "TODO: find a way to keep this from killing the server."
+  Right x -> do (y, tm, sc, sd) <- f c x m
+                return (toBS y, tm, sc, sd)
+
+type ServerReaderHandler' a b =
+  ServerCall ()
+  -> StreamRecv a
+  -> Streaming (Maybe b, MetadataMap, StatusCode, StatusDetails)
+
+convertServerReaderHandler :: (Message a, Message b)
+                           => ServerReaderHandler' a b
+                           -> ServerReaderHandler
+convertServerReaderHandler f c recv =
+  serialize <$> f c (convertRecv recv)
+  where
+    serialize (mmsg, m, sc, sd) = (toBS <$> mmsg, m, sc, sd)
+
+type ServerWriterHandler' a b =
+  ServerCall a
+  -> StreamSend b
+  -> Streaming (MetadataMap, StatusCode, StatusDetails)
+
+convertServerWriterHandler :: (Message a, Message b) =>
+                              ServerWriterHandler' a b
+                              -> ServerWriterHandler
+convertServerWriterHandler f c send =
+  f (convert <$> c) (convertSend send)
+  where
+    convert bs = case fromByteString bs of
+      Left x  -> error $ "deserialization error: " ++ show x -- TODO FIXME
+      Right x -> x
+
+type ServerRWHandler' a b =
+  ServerCall ()
+  -> StreamRecv a
+  -> StreamSend b
+  -> Streaming (MetadataMap, StatusCode, StatusDetails)
+
+convertServerRWHandler :: (Message a, Message b)
+                       => ServerRWHandler' a b
+                       -> ServerRWHandler
+convertServerRWHandler f c recv send =
+  f c (convertRecv recv) (convertSend send)
+
+convertRecv :: Message a => StreamRecv ByteString -> StreamRecv a
+convertRecv =
+  fmap $ \e -> do
+    msg <- e
+    case msg of
+      Nothing -> return Nothing
+      Just bs -> case fromByteString bs of
+                   Left x  -> Left (GRPCIODecodeError x)
+                   Right x -> return (Just x)
+
+convertSend :: Message a => StreamSend ByteString -> StreamSend a
+convertSend s = s . toBS
+
+toBS :: Message a => a -> ByteString
+toBS = BL.toStrict . toLazyByteString
+
+data Handler a where
+  UnaryHandler
+    :: (Message c, Message d)
+    => MethodName
+    -> ServerHandler' c d
+    -> Handler 'Normal
+
+  ClientStreamHandler
+    :: (Message c, Message d)
+    => MethodName
+    -> ServerReaderHandler' c d
+    -> Handler 'ClientStreaming
+
+  ServerStreamHandler
+    :: (Message c, Message d)
+    => MethodName
+    -> ServerWriterHandler' c d
+    -> Handler 'ServerStreaming
+
+  BiDiStreamHandler
+    :: (Message c, Message d)
+    => MethodName
+    -> ServerRWHandler' c d
+    -> Handler 'BiDiStreaming
+
+handlerMethodName :: Handler a -> MethodName
+handlerMethodName (UnaryHandler m _) = m
+handlerMethodName (ClientStreamHandler m _) = m
+handlerMethodName (ServerStreamHandler m _) = m
+handlerMethodName (BiDiStreamHandler m _) = m
+
+-- TODO: find some idiomatic way to do logging that doesn't force the user
+-- into anything they  don't want.
+logShow :: Show a => a -> IO ()
+logShow = print
+
+logAskReport :: Show a => a -> IO ()
+logAskReport x =
+  logShow $ show x ++ " This probably indicates a bug in gRPC-haskell. Please report this error."
+
+-- | Handles errors that result from trying to handle a call on the server.
+-- For each error, takes a different action depending on the severity in the
+-- context of handling a server call. This also tries to give an indication of
+-- whether the error is our fault or user error.
+handleCallError :: Either GRPCIOError a -> IO ()
+handleCallError (Right _) = return ()
+handleCallError (Left GRPCIOTimeout) =
+  --Probably a benign timeout (such as a client disappearing), noop for now.
+  return ()
+handleCallError (Left GRPCIOShutdown) =
+  --Server shutting down. Benign.
+  return ()
+handleCallError (Left x) = logAskReport x
+
+loopWError :: IO (Either GRPCIOError a) -> IO ()
+loopWError f = forever $ f >>= handleCallError
+
+--TODO: options for setting initial/trailing metadata
+handleLoop :: Server -> (Handler a, RegisteredMethod a) -> IO ()
+handleLoop s (UnaryHandler _ f, rm) =
+  loopWError $ do
+    grpcDebug' "handleLoop about to block on serverHandleNormalCall"
+    serverHandleNormalCall s rm mempty $ convertServerHandler f
+handleLoop s (ClientStreamHandler _ f, rm) =
+  loopWError $ serverReader s rm mempty $ convertServerReaderHandler f
+handleLoop s (ServerStreamHandler _ f, rm) =
+  loopWError $ serverWriter s rm mempty $ convertServerWriterHandler f
+handleLoop s (BiDiStreamHandler _ f, rm) =
+  loopWError $ serverRW s rm mempty $ convertServerRWHandler f
+
+data ServerOptions = ServerOptions
+                     {optNormalHandlers       :: [Handler 'Normal],
+                      optClientStreamHandlers :: [Handler 'ClientStreaming],
+                      optServerStreamHandlers :: [Handler 'ServerStreaming],
+                      optBiDiStreamHandlers   :: [Handler 'BiDiStreaming],
+                      optServerPort           :: Port,
+                      optUseCompression       :: Bool,
+                      optUserAgentPrefix      :: String,
+                      optUserAgentSuffix      :: String}
+
+defaultOptions :: ServerOptions
+defaultOptions =
+  ServerOptions {optNormalHandlers = [],
+                 optClientStreamHandlers = [],
+                 optServerStreamHandlers = [],
+                 optBiDiStreamHandlers = [],
+                 optServerPort = 50051,
+                 optUseCompression = False,
+                 optUserAgentPrefix = "grpc-haskell/0.0.0",
+                 optUserAgentSuffix = ""}
+
+serverLoop :: ServerOptions -> IO ()
+serverLoop opts =
+  withGRPC $ \grpc ->
+    withServer grpc (mkConfig opts) $ \server -> do
+      let rmsN = zip (optNormalHandlers opts) $ normalMethods server
+      let rmsCS = zip (optClientStreamHandlers opts) $ cstreamingMethods server
+      let rmsSS = zip (optServerStreamHandlers opts) $ sstreamingMethods server
+      let rmsB = zip (optBiDiStreamHandlers opts) $ bidiStreamingMethods server
+      --TODO: Perhaps assert that no methods disappeared after registration.
+      let loop :: forall a. (Handler a, RegisteredMethod a) -> IO ()
+          loop = handleLoop server
+      asyncsN <- mapM async $ map loop rmsN
+      asyncsCS <- mapM async $ map loop rmsCS
+      asyncsSS <- mapM async $ map loop rmsSS
+      asyncsB <- mapM async $ map loop rmsB
+      asyncUnk <- async $ loopWError $ unknownHandler server
+      waitAnyCancel $ asyncUnk : asyncsN ++ asyncsCS ++ asyncsSS ++ asyncsB
+      return ()
+  where
+    mkConfig ServerOptions{..} =
+      ServerConfig
+        {  host = "localhost"
+         , port = optServerPort
+         , methodsToRegisterNormal = map handlerMethodName optNormalHandlers
+         , methodsToRegisterClientStreaming =
+             map handlerMethodName optClientStreamHandlers
+         , methodsToRegisterServerStreaming =
+             map handlerMethodName optServerStreamHandlers
+         , methodsToRegisterBiDiStreaming =
+             map handlerMethodName optBiDiStreamHandlers
+         , serverArgs =
+             ([CompressionAlgArg GrpcCompressDeflate | optUseCompression]
+              ++
+              [UserAgentPrefix optUserAgentPrefix
+               , UserAgentSuffix optUserAgentSuffix])
+        }
+    unknownHandler s =
+      --TODO: is this working?
+      U.serverHandleNormalCall s mempty $ \call _ -> do
+        logShow $ "Requested unknown endpoint: " ++ show (U.callMethod call)
+        return ("", mempty, StatusNotFound,
+                StatusDetails "Unknown method")
diff --git a/src/Network/GRPC/LowLevel.hs b/src/Network/GRPC/LowLevel.hs
index bc69028..1a43277 100644
--- a/src/Network/GRPC/LowLevel.hs
+++ b/src/Network/GRPC/LowLevel.hs
@@ -29,6 +29,7 @@ GRPC
 -- * Configuration options
 , Arg(..)
 , CompressionAlgorithm(..)
+, Port
 
 -- * Server
 , ServerConfig(..)
@@ -37,12 +38,16 @@ GRPC
 , ServerCall(optionalPayload, requestMetadataRecv)
 , withServer
 , serverHandleNormalCall
+, ServerHandler
 , withServerCall
 , serverCallCancel
 , serverCallIsExpired
 , serverReader -- for client streaming
+, ServerReaderHandler
 , serverWriter -- for server streaming
+, ServerWriterHandler
 , serverRW     -- for bidirectional streaming
+, ServerRWHandler
 
 -- * Client
 , ClientConfig(..)
@@ -51,7 +56,10 @@ GRPC
 , ConnectivityState(..)
 , clientConnectivity
 , withClient
-, clientRegisterMethod
+, clientRegisterMethodNormal
+, clientRegisterMethodClientStreaming
+, clientRegisterMethodServerStreaming
+, clientRegisterMethodBiDiStreaming
 , clientRequest
 , clientReader -- for server streaming
 , clientWriter -- for client streaming
@@ -64,6 +72,11 @@ GRPC
 , Op(..)
 , OpRecvResult(..)
 
+-- * Streaming utilities
+, Streaming
+, StreamSend
+, StreamRecv
+
 ) where
 
 import           Network.GRPC.LowLevel.GRPC
diff --git a/src/Network/GRPC/LowLevel/Call.hs b/src/Network/GRPC/LowLevel/Call.hs
index 91e79ad..d850522 100644
--- a/src/Network/GRPC/LowLevel/Call.hs
+++ b/src/Network/GRPC/LowLevel/Call.hs
@@ -1,26 +1,35 @@
 {-# LANGUAGE DataKinds                  #-}
+{-# LANGUAGE DeriveFunctor              #-}
+{-# LANGUAGE FlexibleInstances          #-}
+{-# LANGUAGE GADTs                      #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE KindSignatures             #-}
 {-# LANGUAGE RecordWildCards            #-}
-{-# LANGUAGE FlexibleInstances          #-}
+{-# LANGUAGE ScopedTypeVariables        #-}
+{-# LANGUAGE StandaloneDeriving         #-}
+{-# LANGUAGE TypeFamilies               #-}
 
 -- | This module defines data structures and operations pertaining to registered
 -- calls; for unregistered call support, see
 -- `Network.GRPC.LowLevel.Call.Unregistered`.
 module Network.GRPC.LowLevel.Call where
 
-import           Data.ByteString                (ByteString)
-import           Data.String                    (IsString)
-#ifdef DEBUG
-import           Foreign.Storable               (peek)
-#endif
+import           Control.Monad.Managed                          (Managed, managed)
+import           Control.Exception                              (bracket)
+import           Data.ByteString                                (ByteString)
+import           Data.List                                      (intersperse)
+import           Data.String                                    (IsString)
+import           Foreign.Marshal.Alloc                          (free, malloc)
+import           Foreign.Ptr                                    (Ptr, nullPtr)
+import           Foreign.Storable                               (Storable, peek)
+import           Network.GRPC.LowLevel.CompletionQueue.Internal
+import           Network.GRPC.LowLevel.GRPC                     (MetadataMap,
+                                                                 grpcDebug)
+import qualified Network.GRPC.Unsafe                            as C
+import qualified Network.GRPC.Unsafe.ByteBuffer                 as C
+import qualified Network.GRPC.Unsafe.Op                         as C
 import           System.Clock
 
-import qualified Network.GRPC.Unsafe            as C
-import qualified Network.GRPC.Unsafe.Op         as C
-
-import           Network.GRPC.LowLevel.GRPC     (MetadataMap, grpcDebug)
-
 -- | Models the four types of RPC call supported by gRPC (and correspond to
 -- DataKinds phantom types on RegisteredMethods).
 data GRPCMethodType
@@ -30,6 +39,23 @@ data GRPCMethodType
   | BiDiStreaming
   deriving (Show, Eq, Ord, Enum)
 
+type family MethodPayload a where
+  MethodPayload 'Normal = ByteString
+  MethodPayload 'ClientStreaming = ()
+  MethodPayload 'ServerStreaming = ByteString
+  MethodPayload 'BiDiStreaming = ()
+
+--TODO: try replacing this class with a plain old function so we don't have the
+-- Payloadable constraint everywhere.
+
+payload :: RegisteredMethod mt -> Ptr C.ByteBuffer -> IO (MethodPayload mt)
+payload (RegisteredMethodNormal _ _ _) p =
+  peek p >>= C.copyByteBufferToByteString
+payload (RegisteredMethodClientStreaming _ _ _) _ = return ()
+payload (RegisteredMethodServerStreaming _ _ _) p =
+  peek p >>= C.copyByteBufferToByteString
+payload (RegisteredMethodBiDiStreaming _ _ _) _ = return ()
+
 newtype MethodName = MethodName {unMethodName :: String}
   deriving (Show, Eq, IsString)
 
@@ -53,32 +79,82 @@ endpoint (Host h) (Port p) = Endpoint (h ++ ":" ++ show p)
 -- Contains state for identifying that method in the underlying gRPC
 -- library. Note that we use a DataKind-ed phantom type to help constrain use of
 -- different kinds of registered methods.
-data RegisteredMethod (mt :: GRPCMethodType) = RegisteredMethod
-  { methodType     :: GRPCMethodType
-  , methodName     :: MethodName
-  , methodEndpoint :: Endpoint
-  , methodHandle   :: C.CallHandle
-  }
+data RegisteredMethod (mt :: GRPCMethodType) where
+  RegisteredMethodNormal :: MethodName
+                            -> Endpoint
+                            -> C.CallHandle
+                            -> RegisteredMethod 'Normal
+  RegisteredMethodClientStreaming :: MethodName
+                                     -> Endpoint
+                                     -> C.CallHandle
+                                     -> RegisteredMethod 'ClientStreaming
+  RegisteredMethodServerStreaming :: MethodName
+                                     -> Endpoint
+                                     -> C.CallHandle
+                                     -> RegisteredMethod 'ServerStreaming
+  RegisteredMethodBiDiStreaming :: MethodName
+                                   -> Endpoint
+                                   -> C.CallHandle
+                                   -> RegisteredMethod 'BiDiStreaming
+
+instance Show (RegisteredMethod a) where
+  show (RegisteredMethodNormal x y z) =
+    "RegisteredMethodNormal "
+    ++ concat (intersperse " " [show x, show y, show z])
+  show (RegisteredMethodClientStreaming x y z) =
+    "RegisteredMethodClientStreaming "
+    ++ concat (intersperse " " [show x, show y, show z])
+  show (RegisteredMethodServerStreaming x y z) =
+    "RegisteredMethodServerStreaming "
+    ++ concat (intersperse " " [show x, show y, show z])
+  show (RegisteredMethodBiDiStreaming x y z) =
+    "RegisteredMethodBiDiStreaming "
+    ++ concat (intersperse " " [show x, show y, show z])
+
+methodName :: RegisteredMethod mt -> MethodName
+methodName (RegisteredMethodNormal x _ _) = x
+methodName (RegisteredMethodClientStreaming x _ _) = x
+methodName (RegisteredMethodServerStreaming x _ _) = x
+methodName (RegisteredMethodBiDiStreaming x _ _) = x
+
+methodEndpoint :: RegisteredMethod mt -> Endpoint
+methodEndpoint (RegisteredMethodNormal _ x _) = x
+methodEndpoint (RegisteredMethodClientStreaming _ x _) = x
+methodEndpoint (RegisteredMethodServerStreaming _ x _) = x
+methodEndpoint (RegisteredMethodBiDiStreaming _ x _) = x
+
+methodHandle :: RegisteredMethod mt -> C.CallHandle
+methodHandle (RegisteredMethodNormal _ _ x) = x
+methodHandle (RegisteredMethodClientStreaming _ _ x) = x
+methodHandle (RegisteredMethodServerStreaming _ _ x) = x
+methodHandle (RegisteredMethodBiDiStreaming _ _ x) = x
+
+methodType :: RegisteredMethod mt -> GRPCMethodType
+methodType (RegisteredMethodNormal _ _ _)          = Normal
+methodType (RegisteredMethodClientStreaming _ _ _) = ClientStreaming
+methodType (RegisteredMethodServerStreaming _ _ _) = ServerStreaming
+methodType (RegisteredMethodBiDiStreaming _ _ _)   = BiDiStreaming
 
 -- | Represents one GRPC call (i.e. request) on the client.
 -- This is used to associate send/receive 'Op's with a request.
-data ClientCall = ClientCall { unClientCall :: C.Call }
+data ClientCall = ClientCall { unsafeCC :: C.Call }
 
 clientCallCancel :: ClientCall -> IO ()
-clientCallCancel cc = C.grpcCallCancel (unClientCall cc) C.reserved
+clientCallCancel cc = C.grpcCallCancel (unsafeCC cc) C.reserved
 
 -- | Represents one registered GRPC call on the server. Contains pointers to all
 -- the C state needed to respond to a registered call.
-data ServerCall = ServerCall
-  { unServerCall        :: C.Call,
-    requestMetadataRecv :: MetadataMap,
-    optionalPayload     :: Maybe ByteString,
-    callDeadline        :: TimeSpec
-  }
+data ServerCall a = ServerCall
+  { unsafeSC            :: C.Call
+  , callCQ              :: CompletionQueue
+  , requestMetadataRecv :: MetadataMap
+  , optionalPayload     :: a
+  , callDeadline        :: TimeSpec
+  } deriving (Functor, Show)
 
-serverCallCancel :: ServerCall -> C.StatusCode -> String -> IO ()
+serverCallCancel :: ServerCall a -> C.StatusCode -> String -> IO ()
 serverCallCancel sc code reason =
-  C.grpcCallCancelWithStatus (unServerCall sc) code reason C.reserved
+  C.grpcCallCancelWithStatus (unsafeSC sc) code reason C.reserved
 
 -- | NB: For now, we've assumed that the method type is all the info we need to
 -- decide the server payload handling method.
@@ -88,7 +164,17 @@ payloadHandling ClientStreaming = C.SrmPayloadNone
 payloadHandling ServerStreaming = C.SrmPayloadReadInitialByteBuffer
 payloadHandling BiDiStreaming   = C.SrmPayloadNone
 
-serverCallIsExpired :: ServerCall -> IO Bool
+-- | Optionally allocate a managed byte buffer for a payload, depending on the
+-- given method type. If no payload is needed, the returned pointer is null
+mgdPayload :: GRPCMethodType -> Managed (Ptr C.ByteBuffer)
+mgdPayload mt
+  | payloadHandling mt == C.SrmPayloadNone = return nullPtr
+  | otherwise                              = managed C.withByteBufferPtr
+
+mgdPtr :: forall a. Storable a => Managed (Ptr a)
+mgdPtr = managed (bracket malloc free)
+
+serverCallIsExpired :: ServerCall a -> IO Bool
 serverCallIsExpired sc = do
   currTime <- getTime Monotonic
   return $ currTime > (callDeadline sc)
@@ -102,27 +188,27 @@ debugClientCall (ClientCall (C.Call ptr)) =
 debugClientCall = const $ return ()
 #endif
 
-debugServerCall :: ServerCall -> IO ()
+debugServerCall :: ServerCall a -> IO ()
 #ifdef DEBUG
-debugServerCall call@(ServerCall (C.Call ptr) _ _ _) = do
-  grpcDebug $ "debugServerCall(R): server call: " ++ (show ptr)
-  grpcDebug $ "debugServerCall(R): metadata ptr: "
-              ++ show (requestMetadataRecv call)
-  grpcDebug $ "debugServerCall(R): payload ptr: " ++ show (optionalPayload call)
-  grpcDebug $ "debugServerCall(R): deadline ptr: " ++ show (callDeadline call)
+debugServerCall sc@(ServerCall (C.Call ptr) _ _ _ _) = do
+  let dbug = grpcDebug . ("debugServerCall(R): " ++)
+  dbug $ "server call: "  ++ show ptr
+  dbug $ "callCQ: "       ++ show (callCQ sc)
+  dbug $ "metadata ptr: " ++ show (requestMetadataRecv sc)
+  dbug $ "deadline ptr: " ++ show (callDeadline sc)
 #else
 {-# INLINE debugServerCall #-}
 debugServerCall = const $ return ()
 #endif
 
 destroyClientCall :: ClientCall -> IO ()
-destroyClientCall ClientCall{..} = do
+destroyClientCall cc = do
   grpcDebug "Destroying client-side call object."
-  C.grpcCallDestroy unClientCall
+  C.grpcCallDestroy (unsafeCC cc)
 
-destroyServerCall :: ServerCall -> IO ()
-destroyServerCall call@ServerCall{..} = do
+destroyServerCall :: ServerCall a -> IO ()
+destroyServerCall sc@ServerCall{ unsafeSC = c } = do
   grpcDebug "destroyServerCall(R): entered."
-  debugServerCall call
-  grpcDebug $ "Destroying server-side call object: " ++ show unServerCall
-  C.grpcCallDestroy unServerCall
+  debugServerCall sc
+  grpcDebug $ "Destroying server-side call object: " ++ show c
+  C.grpcCallDestroy c
diff --git a/src/Network/GRPC/LowLevel/Call/Unregistered.hs b/src/Network/GRPC/LowLevel/Call/Unregistered.hs
index f37d22d..a125cf2 100644
--- a/src/Network/GRPC/LowLevel/Call/Unregistered.hs
+++ b/src/Network/GRPC/LowLevel/Call/Unregistered.hs
@@ -3,23 +3,25 @@
 module Network.GRPC.LowLevel.Call.Unregistered where
 
 import           Control.Monad
-import           Foreign.Marshal.Alloc        (free)
-import           Foreign.Ptr                  (Ptr)
+import           Foreign.Marshal.Alloc                          (free)
+import           Foreign.Ptr                                    (Ptr)
 #ifdef DEBUG
 import           Foreign.Storable             (peek)
 #endif
-import           System.Clock                 (TimeSpec)
+import           Network.GRPC.LowLevel.Call                     (Host (..),
+                                                                 MethodName (..))
+import           Network.GRPC.LowLevel.CompletionQueue.Internal
+import           Network.GRPC.LowLevel.GRPC                     (MetadataMap,
+                                                                 grpcDebug)
+import qualified Network.GRPC.Unsafe                            as C
+import qualified Network.GRPC.Unsafe.Op                         as C
+import           System.Clock                                   (TimeSpec)
 
-import           Network.GRPC.LowLevel.Call   (Host (..), MethodName (..))
-import           Network.GRPC.LowLevel.GRPC   (MetadataMap, grpcDebug)
-import qualified Network.GRPC.Unsafe          as C
-import qualified Network.GRPC.Unsafe.Op as C
-
--- | Represents one unregistered GRPC call on the server.
--- Contains pointers to all the C state needed to respond to an unregistered
--- call.
+-- | Represents one unregistered GRPC call on the server.  Contains pointers to
+-- all the C state needed to respond to an unregistered call.
 data ServerCall = ServerCall
-  { unServerCall        :: C.Call
+  { unsafeSC            :: C.Call
+  , callCQ              :: CompletionQueue
   , requestMetadataRecv :: MetadataMap
   , parentPtr           :: Maybe (Ptr C.Call)
   , callDeadline        :: TimeSpec
@@ -29,18 +31,25 @@ data ServerCall = ServerCall
 
 serverCallCancel :: ServerCall -> C.StatusCode -> String -> IO ()
 serverCallCancel sc code reason =
-  C.grpcCallCancelWithStatus (unServerCall sc) code reason C.reserved
+  C.grpcCallCancelWithStatus (unsafeSC sc) code reason C.reserved
 
 debugServerCall :: ServerCall -> IO ()
 #ifdef DEBUG
 debugServerCall ServerCall{..} = do
-  let C.Call ptr = unServerCall
-  grpcDebug $ "debugServerCall(U): server call: " ++ show ptr
-  grpcDebug $ "debugServerCall(U): metadata: "
-              ++ show requestMetadataRecv
-  grpcDebug $ "debugServerCall(U): deadline: " ++ show callDeadline
-  grpcDebug $ "debugServerCall(U): method: " ++ show callMethod
-  grpcDebug $ "debugServerCall(U): host: " ++ show callHost
+  let C.Call ptr = unsafeSC
+      dbug = grpcDebug . ("debugServerCall(U): " ++)
+
+  dbug $ "server call: " ++ show ptr
+  dbug $ "metadata: "    ++ show requestMetadataRecv
+
+  forM_ parentPtr $ \parentPtr' -> do
+    dbug $ "parent ptr: " ++ show parentPtr'
+    C.Call parent <- peek parentPtr'
+    dbug $ "parent: "     ++ show parent
+
+  dbug $ "deadline: " ++ show callDeadline
+  dbug $ "method: "   ++ show callMethod
+  dbug $ "host: "     ++ show callHost
 #else
 {-# INLINE debugServerCall #-}
 debugServerCall = const $ return ()
@@ -50,7 +59,7 @@ destroyServerCall :: ServerCall -> IO ()
 destroyServerCall call@ServerCall{..} = do
   grpcDebug "destroyServerCall(U): entered."
   debugServerCall call
-  grpcDebug $ "Destroying server-side call object: " ++ show unServerCall
-  C.grpcCallDestroy unServerCall
+  grpcDebug $ "Destroying server-side call object: " ++ show unsafeSC
+  C.grpcCallDestroy unsafeSC
   grpcDebug $ "freeing parentPtr: " ++ show parentPtr
   forM_ parentPtr free
diff --git a/src/Network/GRPC/LowLevel/Client.hs b/src/Network/GRPC/LowLevel/Client.hs
index 975200b..9cadd96 100644
--- a/src/Network/GRPC/LowLevel/Client.hs
+++ b/src/Network/GRPC/LowLevel/Client.hs
@@ -10,10 +10,8 @@
 -- `Network.GRPC.LowLevel.Client.Unregistered`.
 module Network.GRPC.LowLevel.Client where
 
-import           Control.Arrow
 import           Control.Exception                     (bracket, finally)
 import           Control.Monad
-import           Control.Monad.Trans.Class             (MonadTrans(lift))
 import           Control.Monad.Trans.Except
 import           Data.ByteString                       (ByteString)
 import           Network.GRPC.LowLevel.Call
@@ -26,9 +24,6 @@ import qualified Network.GRPC.Unsafe.Constants         as C
 import qualified Network.GRPC.Unsafe.Op                as C
 import qualified Network.GRPC.Unsafe.Time              as C
 
-import qualified Pipes                                 as P
-import qualified Pipes.Core                            as P
-
 -- | Represents the context needed to perform client-side gRPC operations.
 data Client = Client {clientChannel :: C.Channel,
                       clientCQ      :: CompletionQueue,
@@ -76,17 +71,54 @@ clientConnectivity :: Client -> IO C.ConnectivityState
 clientConnectivity Client{..} =
   C.grpcChannelCheckConnectivityState clientChannel False
 
+--TODO: We should probably also register client methods on startup.
+
 -- | Register a method on the client so that we can call it with
 -- 'clientRequest'.
 clientRegisterMethod :: Client
                      -> MethodName
-                     -> GRPCMethodType
-                     -> IO (RegisteredMethod mt)
-clientRegisterMethod Client{..} meth mty = do
+                     -> IO (C.CallHandle)
+clientRegisterMethod Client{..} meth = do
   let e = clientEndpoint clientConfig
-  RegisteredMethod mty meth e <$>
-    C.grpcChannelRegisterCall clientChannel
-      (unMethodName meth) (unEndpoint e) C.reserved
+  C.grpcChannelRegisterCall clientChannel
+                            (unMethodName meth)
+                            (unEndpoint e)
+                            C.reserved
+
+
+clientRegisterMethodNormal :: Client
+                           -> MethodName
+                           -> IO (RegisteredMethod 'Normal)
+clientRegisterMethodNormal c meth = do
+  let e = clientEndpoint (clientConfig c)
+  h <- clientRegisterMethod c meth
+  return $ RegisteredMethodNormal meth e h
+
+
+clientRegisterMethodClientStreaming :: Client
+                                    -> MethodName
+                                    -> IO (RegisteredMethod 'ClientStreaming)
+clientRegisterMethodClientStreaming c meth = do
+  let e = clientEndpoint (clientConfig c)
+  h <- clientRegisterMethod c meth
+  return $  RegisteredMethodClientStreaming meth e h
+
+clientRegisterMethodServerStreaming :: Client
+                                    -> MethodName
+                                    -> IO (RegisteredMethod 'ServerStreaming)
+clientRegisterMethodServerStreaming c meth = do
+  let e = clientEndpoint (clientConfig c)
+  h <- clientRegisterMethod c meth
+  return $ RegisteredMethodServerStreaming meth e h
+
+
+clientRegisterMethodBiDiStreaming :: Client
+                                  -> MethodName
+                                  -> IO (RegisteredMethod 'BiDiStreaming)
+clientRegisterMethodBiDiStreaming c meth = do
+  let e = clientEndpoint (clientConfig c)
+  h <- clientRegisterMethod c meth
+  return $ RegisteredMethodBiDiStreaming meth e h
 
 -- | Create a new call on the client for a registered method.
 -- Returns 'Left' if the CQ is shutting down or if the job to create a call
@@ -103,13 +135,13 @@ clientCreateCall c rm ts = clientCreateCallParent c rm ts Nothing
 clientCreateCallParent :: Client
                            -> RegisteredMethod mt
                            -> TimeoutSeconds
-                           -> Maybe ServerCall
+                           -> Maybe (ServerCall a)
                            -- ^ Optional parent call for cascading cancellation.
                            -> IO (Either GRPCIOError ClientCall)
-clientCreateCallParent Client{..} RegisteredMethod{..} timeout parent = do
+clientCreateCallParent Client{..} rm timeout parent = do
   C.withDeadlineSeconds timeout $ \deadline -> do
     channelCreateCall clientChannel parent C.propagateDefaults
-      clientCQ methodHandle deadline
+      clientCQ (methodHandle rm) deadline
 
 -- | Handles safe creation and cleanup of a client call
 withClientCall :: Client
@@ -117,27 +149,26 @@ withClientCall :: Client
                -> TimeoutSeconds
                -> (ClientCall -> IO (Either GRPCIOError a))
                -> IO (Either GRPCIOError a)
-withClientCall client regmethod timeout f =
-  withClientCallParent client regmethod timeout Nothing f
+withClientCall cl rm tm = withClientCallParent cl rm tm Nothing
 
 -- | Handles safe creation and cleanup of a client call, with an optional parent
 -- call parameter. This allows for cancellation to cascade from the parent
 -- `ServerCall` to the created `ClientCall`. Obviously, this is only useful if
 -- the given gRPC client is also a server.
 withClientCallParent :: Client
-                        -> RegisteredMethod mt
-                        -> TimeoutSeconds
-                        -> (Maybe ServerCall)
-                        -- ^ Optional parent call for cascading cancellation.
-                        -> (ClientCall -> IO (Either GRPCIOError a))
-                        -> IO (Either GRPCIOError a)
-withClientCallParent client regmethod timeout parent f = do
-  createResult <- clientCreateCallParent client regmethod timeout parent
-  case createResult of
-    Left x -> return $ Left x
-    Right call -> f call `finally` logDestroy call
-      where logDestroy c = grpcDebug "withClientCall(R): destroying."
-                           >> destroyClientCall c
+                     -> RegisteredMethod mt
+                     -> TimeoutSeconds
+                     -> Maybe (ServerCall a)
+                        -- ^ Optional parent call for cascading cancellation
+                     -> (ClientCall -> IO (Either GRPCIOError a))
+                     -> IO (Either GRPCIOError a)
+withClientCallParent cl rm tm parent f =
+  clientCreateCallParent cl rm tm parent >>= \case
+    Left e  -> return (Left e)
+    Right c -> f c `finally` do
+      debugClientCall c
+      grpcDebug "withClientCall(R): destroying."
+      destroyClientCall c
 
 data NormalRequestResult = NormalRequestResult
   { rspBody :: ByteString
@@ -166,7 +197,7 @@ compileNormalRequestResults x =
 -- clientReader (client side of server streaming mode)
 
 -- | First parameter is initial server metadata.
-type ClientReaderHandler = MetadataMap -> StreamRecv -> Streaming ()
+type ClientReaderHandler = MetadataMap -> StreamRecv ByteString -> Streaming ()
 
 clientReader :: Client
              -> RegisteredMethod 'ServerStreaming
@@ -178,8 +209,7 @@ clientReader :: Client
 clientReader cl@Client{ clientCQ = cq } rm tm body initMeta f =
   withClientCall cl rm tm go
   where
-    go cc@(unClientCall -> c) = runExceptT $ do
-      lift (debugClientCall cc)
+    go (unsafeCC -> c) = runExceptT $ do
       runOps' c cq [ OpSendInitialMetadata initMeta
                    , OpSendMessage body
                    , OpSendCloseFromClient
@@ -191,7 +221,7 @@ clientReader cl@Client{ clientCQ = cq } rm tm body initMeta f =
 --------------------------------------------------------------------------------
 -- clientWriter (client side of client streaming mode)
 
-type ClientWriterHandler = StreamSend -> Streaming ()
+type ClientWriterHandler = StreamSend ByteString -> Streaming ()
 type ClientWriterResult  = (Maybe ByteString, MetadataMap, MetadataMap,
                               C.StatusCode, StatusDetails)
 
@@ -209,9 +239,8 @@ clientWriterCmn :: Client -- ^ The active client
                 -> ClientWriterHandler
                 -> ClientCall -- ^ The active client call
                 -> IO (Either GRPCIOError ClientWriterResult)
-clientWriterCmn (clientCQ -> cq) initMeta f cc@(unClientCall -> c) =
+clientWriterCmn (clientCQ -> cq) initMeta f (unsafeCC -> c) =
   runExceptT $ do
-    lift (debugClientCall cc)
     sendInitialMetadata c cq initMeta
     runStreamingProxy "clientWriterCmn" c cq (f streamSend)
     sendSingle c cq OpSendCloseFromClient
@@ -231,7 +260,10 @@ pattern CWRFinal mmsg initMD trailMD st ds
 -- clientRW (client side of bidirectional streaming mode)
 
 -- | First parameter is initial server metadata.
-type ClientRWHandler = MetadataMap -> StreamRecv -> StreamSend -> Streaming ()
+type ClientRWHandler = MetadataMap
+                       -> StreamRecv ByteString
+                       -> StreamSend ByteString
+                       -> Streaming ()
 
 -- | For bidirectional-streaming registered requests
 clientRW :: Client
@@ -241,16 +273,15 @@ clientRW :: Client
             -- ^ request metadata
          -> ClientRWHandler
          -> IO (Either GRPCIOError (MetadataMap, C.StatusCode, StatusDetails))
-clientRW c@Client{ clientCQ = cq } rm tm initMeta f =
-  withClientCall c rm tm go
+clientRW cl@(clientCQ -> cq) rm tm initMeta f =
+  withClientCall cl rm tm go
   where
-    go cc@(unClientCall -> call) = runExceptT $ do
-      lift (debugClientCall cc)
-      sendInitialMetadata call cq initMeta
-      srvMeta <- recvInitialMetadata call cq
-      runStreamingProxy "clientRW" call cq (f srvMeta streamRecv streamSend)
-      runOps' call cq [OpSendCloseFromClient] -- WritesDone()
-      recvStatusOnClient call cq -- Finish()
+    go (unsafeCC -> c) = runExceptT $ do
+      sendInitialMetadata c cq initMeta
+      srvMeta <- recvInitialMetadata c cq
+      runStreamingProxy "clientRW" c cq (f srvMeta streamRecv streamSend)
+      runOps' c cq [OpSendCloseFromClient] -- WritesDone()
+      recvStatusOnClient c cq -- Finish()
 
 --------------------------------------------------------------------------------
 -- clientRequest (client side of normal request/response)
@@ -265,15 +296,13 @@ clientRequest :: Client
               -> MetadataMap
               -- ^ Metadata to send with the request
               -> IO (Either GRPCIOError NormalRequestResult)
-clientRequest c@Client{ clientCQ = cq } rm tm body initMeta =
-  withClientCall c rm tm (fmap join . go)
+clientRequest cl@(clientCQ -> cq) rm tm body initMeta =
+  withClientCall cl rm tm (fmap join . go)
   where
-    go cc@(unClientCall -> call) = do
-      grpcDebug "clientRequest(R): created call."
-      debugClientCall cc
+    go (unsafeCC -> c) =
       -- NB: the send and receive operations below *must* be in separate
       -- batches, or the client hangs when the server can't be reached.
-      runOps call cq
+      runOps c cq
         [ OpSendInitialMetadata initMeta
         , OpSendMessage body
         , OpSendCloseFromClient
@@ -283,7 +312,7 @@ clientRequest c@Client{ clientCQ = cq } rm tm body initMeta =
             grpcDebug "clientRequest(R) : batch error sending."
             return $ Left x
           Right rs ->
-            runOps call cq
+            runOps c cq
               [ OpRecvInitialMetadata
               , OpRecvMessage
               , OpRecvStatusOnClient
diff --git a/src/Network/GRPC/LowLevel/Client/Unregistered.hs b/src/Network/GRPC/LowLevel/Client/Unregistered.hs
index 0fe6da9..8800952 100644
--- a/src/Network/GRPC/LowLevel/Client/Unregistered.hs
+++ b/src/Network/GRPC/LowLevel/Client/Unregistered.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE RecordWildCards #-}
+{-# LANGUAGE ViewPatterns    #-}
 
 module Network.GRPC.LowLevel.Client.Unregistered where
 
@@ -59,15 +60,17 @@ clientRequest :: Client
               -> MetadataMap
               -- ^ Request metadata.
               -> IO (Either GRPCIOError NormalRequestResult)
-clientRequest client@Client{..} meth timeLimit body meta =
-  fmap join $ withClientCall client meth timeLimit $ \call -> do
-    results <- runOps (unClientCall call) clientCQ
-                 [ OpSendInitialMetadata meta
-                 , OpSendMessage body
-                 , OpSendCloseFromClient
-                 , OpRecvInitialMetadata
-                 , OpRecvMessage
-                 , OpRecvStatusOnClient
-                 ]
-    grpcDebug "clientRequest(U): ops ran."
-    return $ right compileNormalRequestResults results
+clientRequest cl@(clientCQ -> cq) meth tm body initMeta =
+  join <$> withClientCall cl meth tm go
+  where
+    go (unsafeCC -> c) = do
+      results <- runOps c cq
+                   [ OpSendInitialMetadata initMeta
+                   , OpSendMessage body
+                   , OpSendCloseFromClient
+                   , OpRecvInitialMetadata
+                   , OpRecvMessage
+                   , OpRecvStatusOnClient
+                   ]
+      grpcDebug "clientRequest(U): ops ran."
+      return $ right compileNormalRequestResults results
diff --git a/src/Network/GRPC/LowLevel/CompletionQueue.hs b/src/Network/GRPC/LowLevel/CompletionQueue.hs
index 9b436df..fbdc2b0 100644
--- a/src/Network/GRPC/LowLevel/CompletionQueue.hs
+++ b/src/Network/GRPC/LowLevel/CompletionQueue.hs
@@ -16,6 +16,7 @@
 {-# LANGUAGE RecordWildCards     #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TupleSections       #-}
+{-# LANGUAGE ViewPatterns        #-}
 
 module Network.GRPC.LowLevel.CompletionQueue
   ( CompletionQueue
@@ -40,7 +41,6 @@ import           Control.Concurrent.STM.TVar                    (newTVarIO,
                                                                  readTVar,
                                                                  writeTVar)
 import           Control.Exception                              (bracket)
-import           Control.Monad                                  (liftM2)
 import           Control.Monad.Managed
 import           Control.Monad.Trans.Class                      (MonadTrans (lift))
 import           Control.Monad.Trans.Except
@@ -120,7 +120,7 @@ shutdownCompletionQueue CompletionQueue{..} = do
             C.OpComplete -> drainLoop
 
 channelCreateCall :: C.Channel
-                  -> (Maybe ServerCall)
+                  -> Maybe (ServerCall a)
                   -> C.PropagationMask
                   -> CompletionQueue
                   -> C.CallHandle
@@ -129,7 +129,7 @@ channelCreateCall :: C.Channel
 channelCreateCall
   chan parent mask cq@CompletionQueue{..} handle deadline =
   withPermission Push cq $ do
-    let parentPtr = maybe (C.Call nullPtr) unServerCall parent
+    let parentPtr = maybe (C.Call nullPtr) unsafeSC parent
     grpcDebug $ "channelCreateCall: call with "
                 ++ concat (intersperse " " [show chan, show parentPtr,
                                             show mask,
@@ -140,56 +140,50 @@ channelCreateCall
     return $ Right $ ClientCall call
 
 -- | Create the call object to handle a registered call.
-serverRequestCall :: C.Server
-                  -> CompletionQueue
-                  -> RegisteredMethod mt
-                  -> IO (Either GRPCIOError ServerCall)
-serverRequestCall s cq@CompletionQueue{.. } rm =
+serverRequestCall :: RegisteredMethod mt
+                  -> C.Server
+                  -> CompletionQueue -- ^ server CQ
+                  -> CompletionQueue -- ^ call CQ
+                  -> IO (Either GRPCIOError (ServerCall (MethodPayload mt)))
+serverRequestCall rm s scq ccq =
   -- NB: The method type dictates whether or not a payload is present, according
   -- to the payloadHandling function. We do not allocate a buffer for the
   -- payload when it is not present.
-  withPermission Push cq . with allocs $ \(dead, call, pay, meta) -> do
-    dbug "pre-pluck block"
-    withPermission Pluck cq $ do
+  withPermission Push scq . with allocs $ \(dead, call, pay, meta) ->
+    withPermission Pluck scq $ do
       md  <- peek meta
-      tag <- newTag cq
+      tag <- newTag scq
       dbug $ "got pluck permission, registering call for tag=" ++ show tag
-      ce <- C.grpcServerRequestRegisteredCall s (methodHandle rm) call dead md pay unsafeCQ unsafeCQ tag
+      ce <- C.grpcServerRequestRegisteredCall s (methodHandle rm) call dead md
+              pay (unsafeCQ ccq) (unsafeCQ scq) tag
       runExceptT $ case ce of
         C.CallOk -> do
           ExceptT $ do
-            r <- pluck' cq tag Nothing
+            r <- pluck' scq tag Nothing
             dbug $ "pluck' finished:" ++ show r
             return r
           lift $
             ServerCall
             <$> peek call
+            <*> return ccq
             <*> C.getAllMetadataArray md
-            <*> (if havePay then toBS pay else return Nothing)
+            <*> payload rm pay
             <*> convertDeadline dead
         _ -> do
           lift $ dbug $ "Throwing callError: " ++ show ce
           throwE (GRPCIOCallError ce)
   where
-    allocs = (,,,) <$> ptr <*> ptr <*> pay <*> md
-      where
-        md  = managed C.withMetadataArrayPtr
-        pay = if havePay then managed C.withByteBufferPtr else return nullPtr
-        ptr :: forall a. Storable a => Managed (Ptr a)
-        ptr = managed (bracket malloc free)
-    dbug    = grpcDebug . ("serverRequestCall(R): " ++)
-    havePay = payloadHandling (methodType rm) /= C.SrmPayloadNone
-    toBS p  = peek p >>= \bb@(C.ByteBuffer rawPtr) ->
-      if | rawPtr == nullPtr -> return Nothing
-         | otherwise         -> Just <$> C.copyByteBufferToByteString bb
-    convertDeadline deadline = do
-      deadline' <- C.timeSpec <$> peek deadline
-      -- On OS X, gRPC gives us a deadline that is just a delta, so we convert
-      -- it to an actual deadline.
-      if os == "darwin"
-        then do now <- getTime Monotonic
-                return $ now + deadline'
-        else return deadline'
+    allocs = (,,,)
+      <$> mgdPtr
+      <*> mgdPtr
+      <*> mgdPayload (methodType rm)
+      <*> managed C.withMetadataArrayPtr
+    dbug = grpcDebug . ("serverRequestCall(R): " ++)
+    -- On OS X, gRPC gives us a deadline that is just a delta, so we convert
+    -- it to an actual deadline.
+    convertDeadline (fmap C.timeSpec . peek -> d)
+      | os == "darwin" = (+) <$> d <*> getTime Monotonic
+      | otherwise      = d
 
 -- | Register the server's completion queue. Must be done before the server is
 -- started.
diff --git a/src/Network/GRPC/LowLevel/CompletionQueue/Internal.hs b/src/Network/GRPC/LowLevel/CompletionQueue/Internal.hs
index 6aa29a6..e0215ff 100644
--- a/src/Network/GRPC/LowLevel/CompletionQueue/Internal.hs
+++ b/src/Network/GRPC/LowLevel/CompletionQueue/Internal.hs
@@ -5,7 +5,6 @@ module Network.GRPC.LowLevel.CompletionQueue.Internal where
 import           Control.Concurrent.STM        (atomically, retry)
 import           Control.Concurrent.STM.TVar   (TVar, modifyTVar', readTVar,
                                                 writeTVar)
-import           Control.Monad.IO.Class
 import           Control.Exception             (bracket)
 import           Control.Monad
 import           Data.IORef                    (IORef, atomicModifyIORef')
@@ -62,6 +61,8 @@ data CompletionQueue = CompletionQueue {unsafeCQ        :: C.CompletionQueue,
                                         -- items pushed onto the queue.
                                        }
 
+instance Show CompletionQueue where show = show . unsafeCQ
+
 type TimeoutSeconds = Int
 
 data CQOpType = Push | Pluck deriving (Show, Eq, Enum)
diff --git a/src/Network/GRPC/LowLevel/CompletionQueue/Unregistered.hs b/src/Network/GRPC/LowLevel/CompletionQueue/Unregistered.hs
index ce4818f..f217ba5 100644
--- a/src/Network/GRPC/LowLevel/CompletionQueue/Unregistered.hs
+++ b/src/Network/GRPC/LowLevel/CompletionQueue/Unregistered.hs
@@ -1,10 +1,20 @@
-{-# LANGUAGE RecordWildCards #-}
+{-# LANGUAGE LambdaCase          #-}
+{-# LANGUAGE MultiWayIf          #-}
+{-# LANGUAGE PolyKinds           #-}
+{-# LANGUAGE RecordWildCards     #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE TupleSections       #-}
+{-# LANGUAGE ViewPatterns        #-}
 
 module Network.GRPC.LowLevel.CompletionQueue.Unregistered where
 
 import           Control.Exception                              (bracket)
+import           Control.Monad.Managed
+import           Control.Monad.Trans.Class                      (MonadTrans (lift))
+import           Control.Monad.Trans.Except
 import           Foreign.Marshal.Alloc                          (free, malloc)
-import           Foreign.Storable                               (peek)
+import           Foreign.Ptr                                    (Ptr)
+import           Foreign.Storable                               (Storable, peek)
 import           Network.GRPC.LowLevel.Call
 import qualified Network.GRPC.LowLevel.Call.Unregistered        as U
 import           Network.GRPC.LowLevel.CompletionQueue.Internal
@@ -30,47 +40,37 @@ channelCreateCall chan parent mask cq@CompletionQueue{..} meth endpt deadline =
 
 
 serverRequestCall :: C.Server
-                  -> CompletionQueue
+                  -> CompletionQueue -- ^ server CQ / notification CQ
+                  -> CompletionQueue -- ^ call CQ
                   -> IO (Either GRPCIOError U.ServerCall)
-serverRequestCall server cq@CompletionQueue{..} =
-  withPermission Push cq $
-    bracket malloc free $ \callPtr ->
-      C.withMetadataArrayPtr $ \metadataArrayPtr ->
-        C.withCallDetails $ \callDetails ->
-          withPermission Pluck cq $ do
-            grpcDebug $ "serverRequestCall: callPtr is " ++ show callPtr
-            metadataArray <- peek metadataArrayPtr
-            tag <- newTag cq
-            callError <- C.grpcServerRequestCall server callPtr callDetails
-                           metadataArray unsafeCQ unsafeCQ tag
-            grpcDebug $ "serverRequestCall: callError was " ++ show callError
-            if callError /= C.CallOk
-               then do grpcDebug "serverRequestCall: got call error; cleaning up."
-                       return $ Left $ GRPCIOCallError callError
-               else do pluckResult <- pluck cq tag Nothing
-                       grpcDebug $ "serverRequestCall: pluckResult was "
-                                   ++ show pluckResult
-                       case pluckResult of
-                         Left x -> do
-                           grpcDebug "serverRequestCall: pluck error."
-                           return $ Left x
-                         Right () -> do
-                           rawCall <- peek callPtr
-                           metadata <- C.getAllMetadataArray metadataArray
-                           deadline <- getDeadline callDetails
-                           method <- getMethod callDetails
-                           host <- getHost callDetails
-                           let call = U.ServerCall rawCall
-                                                   metadata
-                                                   Nothing
-                                                   deadline
-                                                   method
-                                                   host
-                           return $ Right call
-
-      where getDeadline callDetails = do
-              C.timeSpec <$> C.callDetailsGetDeadline callDetails
-            getMethod callDetails =
-              MethodName <$> C.callDetailsGetMethod callDetails
-            getHost callDetails =
-              Host <$> C.callDetailsGetHost callDetails
+serverRequestCall s scq ccq =
+  withPermission Push scq . with allocs $ \(call, meta, cd) ->
+    withPermission Pluck scq $ do
+      md  <- peek meta
+      tag <- newTag scq
+      dbug $ "got pluck permission, registering call for tag=" ++ show tag
+      ce  <- C.grpcServerRequestCall s call cd md (unsafeCQ ccq) (unsafeCQ scq) tag
+      runExceptT $ case ce of
+        C.CallOk -> do
+          ExceptT $ do
+            r <- pluck' scq tag Nothing
+            dbug $ "pluck' finished: " ++ show r
+            return r
+          lift $
+            U.ServerCall
+              <$> peek call
+              <*> return ccq
+              <*> C.getAllMetadataArray md
+              <*> return Nothing
+              <*> (C.timeSpec <$> C.callDetailsGetDeadline cd)
+              <*> (MethodName <$> C.callDetailsGetMethod   cd)
+              <*> (Host       <$> C.callDetailsGetHost     cd)
+        _ -> do
+          lift $ dbug $ "Throwing callError: " ++ show ce
+          throwE $ GRPCIOCallError ce
+  where
+    allocs = (,,)
+      <$> mgdPtr
+      <*> managed C.withMetadataArrayPtr
+      <*> managed C.withCallDetails
+    dbug = grpcDebug . ("serverRequestCall(U): " ++)
diff --git a/src/Network/GRPC/LowLevel/GRPC.hs b/src/Network/GRPC/LowLevel/GRPC.hs
index 6fdb448..e3f17f5 100644
--- a/src/Network/GRPC/LowLevel/GRPC.hs
+++ b/src/Network/GRPC/LowLevel/GRPC.hs
@@ -11,7 +11,7 @@ import qualified Data.ByteString        as B
 import qualified Data.Map               as M
 import qualified Network.GRPC.Unsafe    as C
 import qualified Network.GRPC.Unsafe.Op as C
-
+import           Proto3.Wire.Decode     (ParseError)
 
 #ifdef DEBUG
 import           GHC.Conc              (myThreadId)
@@ -47,7 +47,7 @@ data GRPCIOError = GRPCIOCallError C.CallError
                    -- reasonable amount of time.
                    | GRPCIOUnknownError
                    | GRPCIOBadStatusCode C.StatusCode StatusDetails
-
+                   | GRPCIODecodeError ParseError
                    | GRPCIOInternalMissingExpectedPayload
                    | GRPCIOInternalUnexpectedRecv String -- debugging description
   deriving (Show, Eq)
diff --git a/src/Network/GRPC/LowLevel/Op.hs b/src/Network/GRPC/LowLevel/Op.hs
index cd16016..616743a 100644
--- a/src/Network/GRPC/LowLevel/Op.hs
+++ b/src/Network/GRPC/LowLevel/Op.hs
@@ -345,12 +345,12 @@ streamingProxy nm c cq = maybe recv send
     run   = lift . runOps c cq
     urecv = GRPCIOInternalUnexpectedRecv . (nm ++)
 
-type StreamRecv = Streaming (Either GRPCIOError (Maybe ByteString))
-streamRecv :: StreamRecv
+type StreamRecv a = Streaming (Either GRPCIOError (Maybe a))
+streamRecv :: StreamRecv ByteString
 streamRecv = P.request Nothing
 
-type StreamSend = ByteString -> Streaming (Either GRPCIOError ())
-streamSend :: StreamSend
+type StreamSend a = a -> Streaming (Either GRPCIOError ())
+streamSend :: StreamSend ByteString
 streamSend = fmap void . P.request . Just
 
 pattern RecvMsgRslt mmsg <- Right [OpRecvMessageResult mmsg]
diff --git a/src/Network/GRPC/LowLevel/Server.hs b/src/Network/GRPC/LowLevel/Server.hs
index 6fce45a..ff53736 100644
--- a/src/Network/GRPC/LowLevel/Server.hs
+++ b/src/Network/GRPC/LowLevel/Server.hs
@@ -1,21 +1,21 @@
-{-# LANGUAGE DataKinds         #-}
-{-# LANGUAGE FlexibleContexts  #-}
-{-# LANGUAGE LambdaCase        #-}
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE PatternSynonyms   #-}
-{-# LANGUAGE RecordWildCards   #-}
-{-# LANGUAGE TupleSections     #-}
-{-# LANGUAGE ViewPatterns      #-}
+{-# LANGUAGE DataKinds           #-}
+{-# LANGUAGE FlexibleContexts    #-}
+{-# LANGUAGE LambdaCase          #-}
+{-# LANGUAGE OverloadedStrings   #-}
+{-# LANGUAGE PatternSynonyms     #-}
+{-# LANGUAGE RecordWildCards     #-}
+{-# LANGUAGE TupleSections       #-}
+{-# LANGUAGE ViewPatterns        #-}
+{-# LANGUAGE RankNTypes          #-}
+{-# LANGUAGE ScopedTypeVariables #-}
 
 -- | This module defines data structures and operations pertaining to registered
 -- servers using registered calls; for unregistered support, see
 -- `Network.GRPC.LowLevel.Server.Unregistered`.
 module Network.GRPC.LowLevel.Server where
 
-import           Control.Arrow
 import           Control.Exception                     (bracket, finally)
 import           Control.Monad
-import           Control.Monad.Trans.Class             (MonadTrans (lift))
 import           Control.Monad.Trans.Except
 import           Data.ByteString                       (ByteString)
 import           Network.GRPC.LowLevel.Call
@@ -25,18 +25,18 @@ import           Network.GRPC.LowLevel.CompletionQueue (CompletionQueue,
                                                         serverRegisterCompletionQueue,
                                                         serverRequestCall,
                                                         serverShutdownAndNotify,
-                                                        shutdownCompletionQueue)
+                                                        shutdownCompletionQueue,
+                                                        withCompletionQueue)
 import           Network.GRPC.LowLevel.GRPC
 import           Network.GRPC.LowLevel.Op
 import qualified Network.GRPC.Unsafe                   as C
 import qualified Network.GRPC.Unsafe.ChannelArgs       as C
 import qualified Network.GRPC.Unsafe.Op                as C
-import qualified Pipes                                 as P
-import qualified Pipes.Core                            as P
 
 -- | Wraps various gRPC state needed to run a server.
 data Server = Server
-  { internalServer       :: C.Server
+  { serverGRPC           :: GRPC
+  , unsafeServer         :: C.Server
   , serverCQ             :: CompletionQueue
   , normalMethods        :: [RegisteredMethod 'Normal]
   , sstreamingMethods    :: [RegisteredMethod 'ServerStreaming]
@@ -52,9 +52,11 @@ data ServerConfig = ServerConfig
     -- used. Setting to "localhost" works fine in tests.
   , port              :: Port
     -- ^ Port on which to listen for requests.
-  , methodsToRegister :: [(MethodName, GRPCMethodType)]
-    -- ^ List of (method name, method type) tuples specifying all methods to
-    -- register.
+  , methodsToRegisterNormal :: [MethodName]
+    -- ^ List of normal (non-streaming) methods to register.
+  , methodsToRegisterClientStreaming :: [MethodName]
+  , methodsToRegisterServerStreaming :: [MethodName]
+  , methodsToRegisterBiDiStreaming :: [MethodName]
   , serverArgs        :: [C.Arg]
   -- ^ Optional arguments for setting up the channel on the server. Supplying an
   -- empty list will cause the channel to use gRPC's default options.
@@ -73,47 +75,47 @@ startServer grpc conf@ServerConfig{..} =
     when (actualPort /= unPort port) $
       error $ "Unable to bind port: " ++ show port
     cq <- createCompletionQueue grpc
+    grpcDebug $ "startServer: server CQ: " ++ show cq
     serverRegisterCompletionQueue server cq
 
     -- Register methods according to their GRPCMethodType kind. It's a bit ugly
     -- to partition them this way, but we get very convenient phantom typing
     -- elsewhere by doing so.
-    (ns, ss, cs, bs) <- do
-      let f (ns, ss, cs, bs) (nm, mt) = do
-            let reg = serverRegisterMethod server nm e mt
-            case mt of
-              Normal          -> (  , ss, cs, bs) . (:ns) <$> reg
-              ServerStreaming -> (ns,   , cs, bs) . (:ss) <$> reg
-              ClientStreaming -> (ns, ss,   , bs) . (:cs) <$> reg
-              BiDiStreaming   -> (ns, ss, cs,   ) . (:bs) <$> reg
-      foldM f ([],[],[],[]) methodsToRegister
-
+    -- TODO: change order of args so we can eta reduce.
+    ns <- mapM (\nm -> serverRegisterMethodNormal server nm e)
+               methodsToRegisterNormal
+    ss <- mapM (\nm -> serverRegisterMethodServerStreaming server nm e)
+               methodsToRegisterServerStreaming
+    cs <- mapM (\nm -> serverRegisterMethodClientStreaming server nm e)
+               methodsToRegisterClientStreaming
+    bs <- mapM (\nm -> serverRegisterMethodBiDiStreaming server nm e)
+               methodsToRegisterBiDiStreaming
     C.grpcServerStart server
-    return $ Server server cq ns ss cs bs conf
+    return $ Server grpc server cq ns ss cs bs conf
 
 stopServer :: Server -> IO ()
 -- TODO: Do method handles need to be freed?
-stopServer Server{..} = do
+stopServer Server{ unsafeServer = s, serverCQ = scq } = do
   grpcDebug "stopServer: calling shutdownNotify."
   shutdownNotify
   grpcDebug "stopServer: cancelling all calls."
-  C.grpcServerCancelAllCalls internalServer
+  C.grpcServerCancelAllCalls s
   grpcDebug "stopServer: call grpc_server_destroy."
-  C.grpcServerDestroy internalServer
+  C.grpcServerDestroy s
   grpcDebug "stopServer: shutting down CQ."
   shutdownCQ
 
   where shutdownCQ = do
-          shutdownResult <- shutdownCompletionQueue serverCQ
+          shutdownResult <- shutdownCompletionQueue scq
           case shutdownResult of
             Left _ -> do putStrLn "Warning: completion queue didn't shut down."
                          putStrLn "Trying to stop server anyway."
             Right _ -> return ()
         shutdownNotify = do
           let shutdownTag = C.tag 0
-          serverShutdownAndNotify internalServer serverCQ shutdownTag
+          serverShutdownAndNotify s scq shutdownTag
           grpcDebug "called serverShutdownAndNotify; plucking."
-          shutdownEvent <- pluck serverCQ shutdownTag (Just 30)
+          shutdownEvent <- pluck scq shutdownTag (Just 30)
           grpcDebug $ "shutdownNotify: got shutdown event" ++ show shutdownEvent
           case shutdownEvent of
             -- This case occurs when we pluck but the queue is already in the
@@ -126,11 +128,42 @@ stopServer Server{..} = do
 withServer :: GRPC -> ServerConfig -> (Server -> IO a) -> IO a
 withServer grpc cfg = bracket (startServer grpc cfg) stopServer
 
+-- | Less precisely-typed registration function used in
+-- 'serverRegisterMethodNormal', 'serverRegisterMethodServerStreaming',
+-- 'serverRegisterMethodClientStreaming', and
+-- 'serverRegisterMethodBiDiStreaming'.
+serverRegisterMethod :: C.Server
+                        -> MethodName
+                        -> Endpoint
+                        -> GRPCMethodType
+                        -> IO (C.CallHandle)
+serverRegisterMethod s nm e mty =
+  C.grpcServerRegisterMethod s
+                             (unMethodName nm)
+                             (unEndpoint e)
+                             (payloadHandling mty)
+
+{-
+TODO: Consolidate the register functions below.
+
+It seems like we'd need true dependent types to use only one
+  registration function. Ideally we'd want a type like
+  serverRegisterMethod :: C.Server
+                          -> MethodName
+                          -> Endpoint
+                          -> (t :: GRPCMethodType)
+                          -> IO (RegisteredMethod (Lifted t))
+
+where `Lifted t` is the type in the t data kind that corresponds to the data
+constructor t the function was given.
+
+-}
+
 -- | Register a method on a server. The 'RegisteredMethod' type can then be used
 -- to wait for a request to arrive. Note: gRPC claims this must be called before
 -- the server is started, so we do it during startup according to the
 -- 'ServerConfig'.
-serverRegisterMethod :: C.Server
+serverRegisterMethodNormal :: C.Server
                      -> MethodName
                      -- ^ method name, e.g. "/foo"
                      -> Endpoint
@@ -139,42 +172,86 @@ serverRegisterMethod :: C.Server
                      -- parameters to start a server in the first place. It
                      -- doesn't seem to have any effect, even if it's filled
                      -- with nonsense.
-                     -> GRPCMethodType
-                     -- ^ Type of method this will be. In the future, this will
-                     -- be used to switch to the correct handling logic.
-                     -> IO (RegisteredMethod mt)
-serverRegisterMethod internalServer meth e mty =
-  RegisteredMethod mty meth e <$> do
-    h <- C.grpcServerRegisterMethod internalServer
-           (unMethodName meth) (unEndpoint e) (payloadHandling mty)
-    grpcDebug $ "registered method handle: " ++ show h ++ " of type " ++ show mty
-    return h
+                     -> IO (RegisteredMethod 'Normal)
+serverRegisterMethodNormal internalServer meth e = do
+  h <- serverRegisterMethod internalServer meth e Normal
+  return $ RegisteredMethodNormal meth e h
+
+serverRegisterMethodClientStreaming
+  :: C.Server
+     -> MethodName
+     -- ^ method name, e.g. "/foo"
+     -> Endpoint
+     -- ^ Endpoint name name, e.g. "localhost:9999". I have no
+     -- idea why this is needed since we have to provide these
+     -- parameters to start a server in the first place. It
+     -- doesn't seem to have any effect, even if it's filled
+     -- with nonsense.
+     -> IO (RegisteredMethod 'ClientStreaming)
+serverRegisterMethodClientStreaming internalServer meth e = do
+  h <- serverRegisterMethod internalServer meth e ClientStreaming
+  return $ RegisteredMethodClientStreaming meth e h
+
+
+serverRegisterMethodServerStreaming
+  :: C.Server
+     -> MethodName
+     -- ^ method name, e.g. "/foo"
+     -> Endpoint
+     -- ^ Endpoint name name, e.g. "localhost:9999". I have no
+     -- idea why this is needed since we have to provide these
+     -- parameters to start a server in the first place. It
+     -- doesn't seem to have any effect, even if it's filled
+     -- with nonsense.
+     -> IO (RegisteredMethod 'ServerStreaming)
+serverRegisterMethodServerStreaming internalServer meth e = do
+  h <- serverRegisterMethod internalServer meth e ServerStreaming
+  return $ RegisteredMethodServerStreaming meth e h
+
+
+serverRegisterMethodBiDiStreaming
+  :: C.Server
+     -> MethodName
+     -- ^ method name, e.g. "/foo"
+     -> Endpoint
+     -- ^ Endpoint name name, e.g. "localhost:9999". I have no
+     -- idea why this is needed since we have to provide these
+     -- parameters to start a server in the first place. It
+     -- doesn't seem to have any effect, even if it's filled
+     -- with nonsense.
+     -> IO (RegisteredMethod 'BiDiStreaming)
+serverRegisterMethodBiDiStreaming internalServer meth e = do
+  h <- serverRegisterMethod internalServer meth e BiDiStreaming
+  return $ RegisteredMethodBiDiStreaming meth e h
 
 -- | Create a 'Call' with which to wait for the invocation of a registered
 -- method.
 serverCreateCall :: Server
                  -> RegisteredMethod mt
-                 -> IO (Either GRPCIOError ServerCall)
-serverCreateCall Server{..} = serverRequestCall internalServer serverCQ
+                 -> CompletionQueue -- ^ call CQ
+                 -> IO (Either GRPCIOError (ServerCall (MethodPayload mt)))
+serverCreateCall Server{..} rm = serverRequestCall rm unsafeServer serverCQ
 
 withServerCall :: Server
                -> RegisteredMethod mt
-               -> (ServerCall -> IO (Either GRPCIOError a))
+               -> (ServerCall (MethodPayload mt) -> IO (Either GRPCIOError a))
                -> IO (Either GRPCIOError a)
-withServerCall server regmethod f = do
-  createResult <- serverCreateCall server regmethod
-  case createResult of
-    Left x -> return $ Left x
-    Right call -> f call `finally` logDestroy call
-      where logDestroy c = grpcDebug "withServerRegisteredCall: destroying."
-                           >> destroyServerCall c
+withServerCall s rm f =
+  withCompletionQueue (serverGRPC s) $
+    serverCreateCall s rm >=> \case
+      Left e  -> return (Left e)
+      Right c -> do
+        debugServerCall c
+        f c `finally` do
+          grpcDebug "withServerCall(R): destroying."
+          destroyServerCall c
 
 --------------------------------------------------------------------------------
 -- serverReader (server side of client streaming mode)
 
 type ServerReaderHandler
-  =  ServerCall
-  -> StreamRecv
+  =  ServerCall ()
+  -> StreamRecv ByteString
   -> Streaming (Maybe ByteString, MetadataMap, C.StatusCode, StatusDetails)
 
 serverReader :: Server
@@ -182,24 +259,23 @@ serverReader :: Server
              -> MetadataMap -- ^ initial server metadata
              -> ServerReaderHandler
              -> IO (Either GRPCIOError ())
-serverReader s@Server{ serverCQ = cq } rm initMeta f = withServerCall s rm go
+serverReader s rm initMeta f = withServerCall s rm go
   where
-    go sc@(unServerCall -> c) = runExceptT $ do
-      lift $ debugServerCall sc
-      (mmsg, trailMD, st, ds) <-
-        runStreamingProxy "serverReader" c cq (f sc streamRecv)
-      runOps' c cq ( OpSendInitialMetadata initMeta
-                   : OpSendStatusFromServer trailMD st ds
-                   : maybe [] ((:[]) . OpSendMessage) mmsg
-                   )
+    go sc@ServerCall{ unsafeSC = c, callCQ = ccq } = runExceptT $ do
+      (mmsg, trailMeta, st, ds) <-
+        runStreamingProxy "serverReader" c ccq (f sc streamRecv)
+      runOps' c ccq ( OpSendInitialMetadata initMeta
+                    : OpSendStatusFromServer trailMeta st ds
+                    : maybe [] ((:[]) . OpSendMessage) mmsg
+                    )
       return ()
 
 --------------------------------------------------------------------------------
 -- serverWriter (server side of server streaming mode)
 
 type ServerWriterHandler
-  =  ServerCall
-  -> StreamSend
+  =  ServerCall ByteString
+  -> StreamSend ByteString
   -> Streaming (MetadataMap, C.StatusCode, StatusDetails)
 
 -- | Wait for and then handle a registered, server-streaming call.
@@ -209,21 +285,20 @@ serverWriter :: Server
              -- ^ Initial server metadata
              -> ServerWriterHandler
              -> IO (Either GRPCIOError ())
-serverWriter s@Server{ serverCQ = cq } rm initMeta f = withServerCall s rm go
+serverWriter s rm initMeta f = withServerCall s rm go
   where
-    go sc@ServerCall{ unServerCall = c } = runExceptT $ do
-      lift (debugServerCall sc)
-      sendInitialMetadata c cq initMeta
-      st <- runStreamingProxy "serverWriter" c cq (f sc streamSend)
-      sendStatusFromServer c cq st
+    go sc@ServerCall{ unsafeSC = c, callCQ = ccq } = runExceptT $ do
+      sendInitialMetadata c ccq initMeta
+      st <- runStreamingProxy "serverWriter" c ccq (f sc streamSend)
+      sendStatusFromServer c ccq st
 
 --------------------------------------------------------------------------------
 -- serverRW (server side of bidirectional streaming mode)
 
 type ServerRWHandler
-  =  ServerCall
-  -> StreamRecv
-  -> StreamSend
+  =  ServerCall ()
+  -> StreamRecv ByteString
+  -> StreamSend ByteString
   -> Streaming (MetadataMap, C.StatusCode, StatusDetails)
 
 serverRW :: Server
@@ -232,13 +307,12 @@ serverRW :: Server
             -- ^ initial server metadata
          -> ServerRWHandler
          -> IO (Either GRPCIOError ())
-serverRW s@Server{ serverCQ = cq } rm initMeta f = withServerCall s rm go
+serverRW s rm initMeta f = withServerCall s rm go
   where
-    go sc@(unServerCall -> c) = runExceptT $ do
-      lift $ debugServerCall sc
-      sendInitialMetadata c cq initMeta
-      st <- runStreamingProxy "serverRW" c cq (f sc streamRecv streamSend)
-      sendStatusFromServer c cq st
+    go sc@ServerCall{ unsafeSC = c, callCQ = ccq } = runExceptT $ do
+      sendInitialMetadata c ccq initMeta
+      st <- runStreamingProxy "serverRW" c ccq (f sc streamRecv streamSend)
+      sendStatusFromServer c ccq st
 
 --------------------------------------------------------------------------------
 -- serverHandleNormalCall (server side of normal request/response)
@@ -250,7 +324,9 @@ serverRW s@Server{ serverCQ = cq } rm initMeta f = withServerCall s rm go
 -- respectively. We pass in the 'ServerCall' so that the server can call
 -- 'serverCallCancel' on it if needed.
 type ServerHandler
-  =  ServerCall -> ByteString -> MetadataMap
+  =  ServerCall ByteString
+  -> ByteString
+  -> MetadataMap
   -> IO (ByteString, MetadataMap, C.StatusCode, StatusDetails)
 
 -- | Wait for and then handle a normal (non-streaming) call.
@@ -260,21 +336,15 @@ serverHandleNormalCall :: Server
                        -- ^ Initial server metadata
                        -> ServerHandler
                        -> IO (Either GRPCIOError ())
-serverHandleNormalCall s@Server{ serverCQ = cq } rm initMeta f =
+serverHandleNormalCall s rm initMeta f =
   withServerCall s rm go
   where
-    go sc@(unServerCall -> call) = do
-      grpcDebug "serverHandleNormalCall(R): starting batch."
-      debugServerCall sc
-      case optionalPayload sc of
-        Nothing  -> return (Left GRPCIOInternalMissingExpectedPayload)
-        Just pay -> do
-          (rspBody, trailMeta, status, ds) <- f sc pay (requestMetadataRecv sc)
-          eea <- runOps call cq
-                   [ OpSendInitialMetadata initMeta
-                   , OpRecvCloseOnServer
-                   , OpSendMessage rspBody
-                   , OpSendStatusFromServer trailMeta status ds
-                   ]
-                 <* grpcDebug "serverHandleNormalCall(R): finished response ops."
-          return (void eea)
+    go sc@ServerCall{..} = do
+      (rsp, trailMeta, st, ds) <- f sc optionalPayload requestMetadataRecv
+      void <$> runOps unsafeSC callCQ
+                 [ OpSendInitialMetadata initMeta
+                 , OpRecvCloseOnServer
+                 , OpSendMessage rsp
+                 , OpSendStatusFromServer trailMeta st ds
+                 ]
+               <* grpcDebug "serverHandleNormalCall(R): finished response ops."
diff --git a/src/Network/GRPC/LowLevel/Server/Unregistered.hs b/src/Network/GRPC/LowLevel/Server/Unregistered.hs
index 103dbcb..51445dc 100644
--- a/src/Network/GRPC/LowLevel/Server/Unregistered.hs
+++ b/src/Network/GRPC/LowLevel/Server/Unregistered.hs
@@ -4,8 +4,10 @@
 module Network.GRPC.LowLevel.Server.Unregistered where
 
 import           Control.Exception                                  (finally)
+import           Control.Monad
 import           Data.ByteString                                    (ByteString)
 import           Network.GRPC.LowLevel.Call.Unregistered
+import           Network.GRPC.LowLevel.CompletionQueue              (CompletionQueue, withCompletionQueue)
 import           Network.GRPC.LowLevel.CompletionQueue.Unregistered (serverRequestCall)
 import           Network.GRPC.LowLevel.GRPC
 import           Network.GRPC.LowLevel.Op                           (Op (..), OpRecvResult (..),
@@ -13,20 +15,21 @@ import           Network.GRPC.LowLevel.Op                           (Op (..), Op
 import           Network.GRPC.LowLevel.Server                       (Server (..))
 import qualified Network.GRPC.Unsafe.Op                             as C
 
-serverCreateCall :: Server -> IO (Either GRPCIOError ServerCall)
-serverCreateCall Server{..} =
-  serverRequestCall internalServer serverCQ
+serverCreateCall :: Server
+                 -> CompletionQueue -- ^ call CQ
+                 -> IO (Either GRPCIOError ServerCall)
+serverCreateCall Server{..} = serverRequestCall unsafeServer serverCQ
 
 withServerCall :: Server
-                  -> (ServerCall -> IO (Either GRPCIOError a))
-                  -> IO (Either GRPCIOError a)
-withServerCall server f = do
-  createResult <- serverCreateCall server
-  case createResult of
-    Left x -> return $ Left x
-    Right call -> f call `finally` logDestroy call
-      where logDestroy c = grpcDebug "withServerCall: destroying."
-                           >> destroyServerCall c
+               -> (ServerCall -> IO (Either GRPCIOError a))
+               -> IO (Either GRPCIOError a)
+withServerCall s f =
+  withCompletionQueue (serverGRPC s) $
+    serverCreateCall s >=> \case
+      Left e  -> return (Left e)
+      Right c -> f c `finally` do
+        grpcDebug "withServerCall: destroying."
+        destroyServerCall c
 
 -- | Sequence of 'Op's needed to receive a normal (non-streaming) call.
 -- TODO: We have to put 'OpRecvCloseOnServer' in the response ops, or else the
@@ -51,7 +54,8 @@ serverOpsSendNormalResponse body metadata code details =
 -- | A handler for an unregistered server call; bytestring arguments are the
 -- request body and response body respectively.
 type ServerHandler
-  =  ServerCall -> ByteString
+  =  ServerCall
+  -> ByteString
   -> IO (ByteString, MetadataMap, C.StatusCode, StatusDetails)
 
 -- | Handle one unregistered call.
@@ -59,31 +63,32 @@ serverHandleNormalCall :: Server
                        -> MetadataMap -- ^ Initial server metadata.
                        -> ServerHandler
                        -> IO (Either GRPCIOError ())
-serverHandleNormalCall s@Server{..} srvMetadata f =
-  withServerCall s $ \call@ServerCall{..} -> do
-    grpcDebug "serverHandleNormalCall(U): starting batch."
-    runOps unServerCall serverCQ
-      [ OpSendInitialMetadata srvMetadata
-      , OpRecvMessage
-      ]
-      >>= \case
-        Left x -> do
-          grpcDebug "serverHandleNormalCall(U): ops failed; aborting"
-          return $ Left x
-        Right [OpRecvMessageResult (Just body)] -> do
-          grpcDebug $ "got client metadata: " ++ show requestMetadataRecv
-          grpcDebug $ "call_details host is: " ++ show callHost
-          (rspBody, rspMeta, status, ds) <- f call body
-          runOps unServerCall serverCQ
-            [ OpRecvCloseOnServer
-            , OpSendMessage rspBody,
-              OpSendStatusFromServer rspMeta status ds
-            ]
-            >>= \case
-              Left x -> do
-                grpcDebug "serverHandleNormalCall(U): resp failed."
-                return $ Left x
-              Right _ -> do
-                grpcDebug "serverHandleNormalCall(U): ops done."
-                return $ Right ()
-        x -> error $ "impossible pattern match: " ++ show x
+serverHandleNormalCall s initMeta f = withServerCall s go
+  where
+    go sc@ServerCall{ unsafeSC = c, callCQ = cq, .. } = do
+      grpcDebug "serverHandleNormalCall(U): starting batch."
+      runOps c cq
+        [ OpSendInitialMetadata initMeta
+        , OpRecvMessage
+        ]
+        >>= \case
+          Left x -> do
+            grpcDebug "serverHandleNormalCall(U): ops failed; aborting"
+            return $ Left x
+          Right [OpRecvMessageResult (Just body)] -> do
+            grpcDebug $ "got client metadata: " ++ show requestMetadataRecv
+            grpcDebug $ "call_details host is: " ++ show callHost
+            (rsp, trailMeta, st, ds) <- f sc body
+            runOps c cq
+              [ OpRecvCloseOnServer
+              , OpSendMessage rsp,
+                OpSendStatusFromServer trailMeta st ds
+              ]
+              >>= \case
+                Left x -> do
+                  grpcDebug "serverHandleNormalCall(U): resp failed."
+                  return $ Left x
+                Right _ -> do
+                  grpcDebug "serverHandleNormalCall(U): ops done."
+                  return $ Right ()
+          x -> error $ "impossible pattern match: " ++ show x
diff --git a/stack.yaml b/stack.yaml
index 1d865d1..b75ca7f 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -7,6 +7,14 @@ resolver: lts-5.10
 # Local packages, usually specified by relative directory name
 packages:
 - '.'
+- location:
+    git: git@github.mv.awakenetworks.net:awakenetworks/protobuf-wire.git
+    commit: e5a6985eeb5eb1eded7b46b2892874000e2ae835
+  extra-dep: true
+- location:
+    git: git@github.mv.awakenetworks.net:awakenetworks/proto3-wire.git
+    commit: 9898a793ab61fd582b5b7172d349ffd248b20095
+  extra-dep: true
 # Packages to be pulled from upstream that are not in the resolver (e.g., acme-missiles-0.3)
 extra-deps: [managed-1.0.5]
 
diff --git a/tests/LowLevelTests.hs b/tests/LowLevelTests.hs
index 92e8de8..7271be5 100644
--- a/tests/LowLevelTests.hs
+++ b/tests/LowLevelTests.hs
@@ -70,24 +70,24 @@ testClientCreateDestroy =
 testClientTimeoutNoServer :: TestTree
 testClientTimeoutNoServer =
   clientOnlyTest "request timeout when server DNE" $ \c -> do
-    rm <- clientRegisterMethod c "/foo" Normal
+    rm <- clientRegisterMethodNormal c "/foo"
     r  <- clientRequest c rm 1 "Hello" mempty
     r @?= Left GRPCIOTimeout
 
 testServerCreateDestroy :: TestTree
 testServerCreateDestroy =
-  serverOnlyTest "start/stop" [] nop
+  serverOnlyTest "start/stop" (["/foo"],[],[],[]) nop
 
 testMixRegisteredUnregistered :: TestTree
 testMixRegisteredUnregistered =
   csTest "server uses unregistered calls to handle unknown endpoints"
          client
          server
-         [("/foo", Normal)]
+         (["/foo"],[],[],[])
   where
     client c = do
-      rm1 <- clientRegisterMethod c "/foo" Normal
-      rm2 <- clientRegisterMethod c "/bar" Normal
+      rm1 <- clientRegisterMethodNormal c "/foo"
+      rm2 <- clientRegisterMethodNormal c "/bar"
       clientRequest c rm1 1 "Hello" mempty >>= do
         checkReqRslt $ \NormalRequestResult{..} -> do
           rspBody @?= "reply test"
@@ -121,11 +121,11 @@ testMixRegisteredUnregistered =
 -- tweak EH behavior / async use.
 testPayload :: TestTree
 testPayload =
-  csTest "registered normal request/response" client server [("/foo", Normal)]
+  csTest "registered normal request/response" client server (["/foo"],[],[],[])
   where
     clientMD = [("foo_key", "foo_val"), ("bar_key", "bar_val")]
     client c = do
-      rm <- clientRegisterMethod c "/foo" Normal
+      rm <- clientRegisterMethodNormal c "/foo"
       clientRequest c rm 10 "Hello!" clientMD >>= do
         checkReqRslt $ \NormalRequestResult{..} -> do
           rspCode @?= StatusOk
@@ -143,10 +143,10 @@ testPayload =
 
 testServerCancel :: TestTree
 testServerCancel =
-  csTest "server cancel call" client server [("/foo", Normal)]
+  csTest "server cancel call" client server (["/foo"],[],[],[])
   where
     client c = do
-      rm <- clientRegisterMethod c "/foo" Normal
+      rm <- clientRegisterMethodNormal c "/foo"
       res <- clientRequest c rm 10 "" mempty
       res @?= badStatus StatusCancelled
     server s = do
@@ -158,7 +158,7 @@ testServerCancel =
 
 testServerStreaming :: TestTree
 testServerStreaming =
-  csTest "server streaming" client server [("/feed", ServerStreaming)]
+  csTest "server streaming" client server ([],[],["/feed"],[])
   where
     clientInitMD = [("client","initmd")]
     serverInitMD = [("server","initmd")]
@@ -166,7 +166,7 @@ testServerStreaming =
     pays         = ["ONE", "TWO", "THREE", "FOUR"] :: [ByteString]
 
     client c = do
-      rm <- clientRegisterMethod c "/feed" ServerStreaming
+      rm <- clientRegisterMethodServerStreaming c "/feed"
       eea <- clientReader c rm 10 clientPay clientInitMD $ \initMD recv -> do
         liftIO $ checkMD "Server initial metadata mismatch" serverInitMD initMD
         forM_ pays $ \p -> recv `is` Right (Just p)
@@ -175,20 +175,18 @@ testServerStreaming =
 
     server s = do
       let rm = head (sstreamingMethods s)
-      eea <- serverWriter s rm serverInitMD $ \sc send -> do
+      r <- serverWriter s rm serverInitMD $ \sc send -> do
         liftIO $ do
-          checkMD "Client request metadata mismatch"
+          checkMD "Server request metadata mismatch"
             clientInitMD (requestMetadataRecv sc)
-          case optionalPayload sc of
-            Nothing  -> assertFailure "expected optional payload"
-            Just pay -> pay @?= clientPay
+          optionalPayload sc @?= clientPay
         forM_ pays $ \p -> send p `is` Right ()
         return (dummyMeta, StatusOk, "dtls")
-      eea @?= Right ()
+      r @?= Right ()
 
 testClientStreaming :: TestTree
 testClientStreaming =
-  csTest "client streaming" client server [("/slurp", ClientStreaming)]
+  csTest "client streaming" client server ([],["/slurp"],[],[])
   where
     clientInitMD = [("a","b")]
     serverInitMD = [("x","y")]
@@ -199,7 +197,7 @@ testClientStreaming =
     pays         = ["P_ONE", "P_TWO", "P_THREE"] :: [ByteString]
 
     client c = do
-      rm  <- clientRegisterMethod c "/slurp" ClientStreaming
+      rm  <- clientRegisterMethodClientStreaming c "/slurp"
       eea <- clientWriter c rm 10 clientInitMD $ \send -> do
         -- liftIO $ checkMD "Server initial metadata mismatch" serverInitMD initMD
         forM_ pays $ \p -> send p `is` Right ()
@@ -217,19 +215,18 @@ testClientStreaming =
 
 testBiDiStreaming :: TestTree
 testBiDiStreaming =
-  csTest "bidirectional streaming" client server [("/bidi", BiDiStreaming)]
+  csTest "bidirectional streaming" client server ([],[],[],["/bidi"])
   where
     clientInitMD = [("bidi-streaming","client")]
     serverInitMD = [("bidi-streaming","server")]
     trailMD      = dummyMeta
     serverStatus = StatusOk
     serverDtls   = "deets"
+    is act x     = act >>= liftIO . (@?= x)
 
     client c = do
-      rm  <- clientRegisterMethod c "/bidi" BiDiStreaming
+      rm  <- clientRegisterMethodBiDiStreaming c "/bidi"
       eea <- clientRW c rm 10 clientInitMD $ \initMD recv send -> do
-        liftIO $ checkMD "Server initial metadata mismatch"
-                   serverInitMD initMD
         send "cw0" `is` Right ()
         recv       `is` Right (Just "sw0")
         send "cw1" `is` Right ()
@@ -263,13 +260,13 @@ testClientCall =
 
 testServerCall :: TestTree
 testServerCall =
-  serverOnlyTest "create/destroy call" [] $ \s -> do
+  serverOnlyTest "create/destroy call" ([],[],[],[]) $ \s -> do
     r <- U.withServerCall s $ const $ return $ Right ()
     r @?= Left GRPCIOTimeout
 
 testPayloadUnregistered :: TestTree
 testPayloadUnregistered =
-  csTest "unregistered normal request/response" client server []
+  csTest "unregistered normal request/response" client server ([],[],[],[])
   where
     client c =
       U.clientRequest c "/foo" 10 "Hello!" mempty >>= do
@@ -289,10 +286,10 @@ testGoaway =
   csTest "Client handles server shutdown gracefully"
          client
          server
-         [("/foo", Normal)]
+         (["/foo"],[],[],[])
   where
     client c = do
-      rm <- clientRegisterMethod c "/foo" Normal
+      rm <- clientRegisterMethodNormal c "/foo"
       clientRequest c rm 10 "" mempty
       clientRequest c rm 10 "" mempty
       lastResult <- clientRequest c rm 1 "" mempty
@@ -310,10 +307,10 @@ testGoaway =
 
 testSlowServer :: TestTree
 testSlowServer =
-  csTest "Client handles slow server response" client server [("/foo", Normal)]
+  csTest "Client handles slow server response" client server (["/foo"],[],[],[])
   where
     client c = do
-      rm <- clientRegisterMethod c "/foo" Normal
+      rm <- clientRegisterMethodNormal c "/foo"
       result <- clientRequest c rm 1 "" mempty
       result @?= badStatus StatusDeadlineExceeded
     server s = do
@@ -325,10 +322,10 @@ testSlowServer =
 
 testServerCallExpirationCheck :: TestTree
 testServerCallExpirationCheck =
-  csTest "Check for call expiration" client server [("/foo", Normal)]
+  csTest "Check for call expiration" client server (["/foo"],[],[],[])
   where
     client c = do
-      rm <- clientRegisterMethod c "/foo" Normal
+      rm <- clientRegisterMethodNormal c "/foo"
       result <- clientRequest c rm 3 "" mempty
       return ()
     server s = do
@@ -352,10 +349,10 @@ testCustomUserAgent =
     clientArgs = [UserAgentPrefix "prefix!", UserAgentSuffix "suffix!"]
     client =
       TestClient (ClientConfig "localhost" 50051 clientArgs) $
-        \c -> do rm <- clientRegisterMethod c "/foo" Normal
+        \c -> do rm <- clientRegisterMethodNormal c "/foo"
                  result <- clientRequest c rm 4 "" mempty
                  return ()
-    server = TestServer (stdServerConf [("/foo", Normal)]) $ \s -> do
+    server = TestServer (serverConf (["/foo"],[],[],[])) $ \s -> do
       let rm = head (normalMethods s)
       serverHandleNormalCall s rm mempty $ \_ _ meta -> do
         let ua = meta M.! "user-agent"
@@ -373,10 +370,10 @@ testClientCompression =
                    "localhost"
                    50051
                    [CompressionAlgArg GrpcCompressDeflate]) $ \c -> do
-        rm <- clientRegisterMethod c "/foo" Normal
+        rm <- clientRegisterMethodNormal c "/foo"
         result <- clientRequest c rm 1 "hello" mempty
         return ()
-    server = TestServer (stdServerConf [("/foo", Normal)]) $ \s -> do
+    server = TestServer (serverConf (["/foo"],[],[],[])) $ \s -> do
       let rm = head (normalMethods s)
       serverHandleNormalCall s rm mempty $ \_ body _ -> do
         body @?= "hello"
@@ -391,7 +388,7 @@ testClientServerCompression =
                          50051
                          [CompressionAlgArg GrpcCompressDeflate]
     client = TestClient cconf $ \c -> do
-      rm <- clientRegisterMethod c "/foo" Normal
+      rm <- clientRegisterMethodNormal c "/foo"
       clientRequest c rm 1 "hello" mempty >>= do
         checkReqRslt $ \NormalRequestResult{..} -> do
           rspCode @?= StatusOk
@@ -402,7 +399,7 @@ testClientServerCompression =
       return ()
     sconf = ServerConfig "localhost"
                          50051
-                         [("/foo", Normal)]
+                         ["/foo"] [] [] []
                          [CompressionAlgArg GrpcCompressDeflate]
     server = TestServer sconf $ \s -> do
       let rm = head (normalMethods s)
@@ -423,7 +420,7 @@ dummyMeta = [("foo","bar")]
 dummyResp :: (ByteString, MetadataMap, StatusCode, StatusDetails)
 dummyResp = ("", mempty, StatusOk, StatusDetails "")
 
-dummyHandler :: ServerCall -> ByteString -> MetadataMap
+dummyHandler :: ServerCall a -> ByteString -> MetadataMap
                 -> IO (ByteString, MetadataMap, StatusCode, StatusDetails)
 dummyHandler _ _ _ = return dummyResp
 
@@ -441,11 +438,11 @@ nop :: Monad m => a -> m ()
 nop = const (return ())
 
 serverOnlyTest :: TestName
-               -> [(MethodName, GRPCMethodType)]
+               -> ([MethodName],[MethodName],[MethodName],[MethodName])
                -> (Server -> IO ())
                -> TestTree
 serverOnlyTest nm ms =
-  testCase ("Server - " ++ nm) . runTestServer . stdTestServer ms
+  testCase ("Server - " ++ nm) . runTestServer . TestServer (serverConf ms)
 
 clientOnlyTest :: TestName -> (Client -> IO ()) -> TestTree
 clientOnlyTest nm =
@@ -454,9 +451,10 @@ clientOnlyTest nm =
 csTest :: TestName
        -> (Client -> IO ())
        -> (Server -> IO ())
-       -> [(MethodName, GRPCMethodType)]
+       -> ([MethodName],[MethodName],[MethodName],[MethodName])
        -> TestTree
-csTest nm c s ms = csTest' nm (stdTestClient c) (stdTestServer ms s)
+csTest nm c s ms =
+  csTest' nm (stdTestClient c) (TestServer (serverConf ms) s)
 
 csTest' :: TestName -> TestClient -> TestServer -> TestTree
 csTest' nm tc ts =
@@ -505,11 +503,16 @@ runTestServer :: TestServer -> IO ()
 runTestServer (TestServer conf f) =
   runManaged $ mgdGRPC >>= mgdServer conf >>= liftIO . f
 
-stdTestServer :: [(MethodName, GRPCMethodType)] -> (Server -> IO ()) -> TestServer
-stdTestServer = TestServer . stdServerConf
+defServerConf :: ServerConfig
+defServerConf = ServerConfig "localhost" 50051 [] [] [] [] []
 
-stdServerConf :: [(MethodName, GRPCMethodType)] -> ServerConfig
-stdServerConf xs = ServerConfig "localhost" 50051 xs []
+serverConf :: ([MethodName],[MethodName],[MethodName],[MethodName])
+              -> ServerConfig
+serverConf (ns, cs, ss, bs) =
+  defServerConf {methodsToRegisterNormal = ns,
+                 methodsToRegisterClientStreaming = cs,
+                 methodsToRegisterServerStreaming = ss,
+                 methodsToRegisterBiDiStreaming = bs}
 
 threadDelaySecs :: Int -> IO ()
 threadDelaySecs = threadDelay . (* 10^(6::Int))
diff --git a/tests/LowLevelTests/Op.hs b/tests/LowLevelTests/Op.hs
index 559aa7e..275b5ed 100644
--- a/tests/LowLevelTests/Op.hs
+++ b/tests/LowLevelTests/Op.hs
@@ -4,9 +4,7 @@
 
 module LowLevelTests.Op where
 
-import           Control.Concurrent             (threadDelay)
-import           Data.ByteString                (isPrefixOf)
-import           Foreign.Storable               (peek)
+import           Data.ByteString                (ByteString, isPrefixOf)
 import           Test.Tasty
 import           Test.Tasty.HUnit               as HU (testCase, (@?=),
                                                        assertBool)
@@ -16,7 +14,6 @@ import           Network.GRPC.LowLevel.Call
 import           Network.GRPC.LowLevel.Client
 import           Network.GRPC.LowLevel.Server
 import           Network.GRPC.LowLevel.Op
-import           Network.GRPC.LowLevel.CompletionQueue
 
 lowLevelOpTests :: TestTree
 lowLevelOpTests = testGroup "Synchronous unit tests of low-level Op interface"
@@ -29,7 +26,7 @@ testCancelFromServer =
     withClientServerUnaryCall grpc $
     \(Client{..}, Server{..}, ClientCall{..}, sc@ServerCall{..}) -> do
       serverCallCancel sc StatusPermissionDenied "TestStatus"
-      clientRes <- runOps unClientCall clientCQ clientRecvOps
+      clientRes <- runOps unsafeCC clientCQ clientRecvOps
       case clientRes of
         Left x -> error $ "Client recv error: " ++ show x
         Right [_,_,OpRecvStatusOnClientResult _ code details] -> do
@@ -48,12 +45,13 @@ runSerialTest f =
                        Right () -> return ()
 
 withClientServerUnaryCall :: GRPC
-                             -> ((Client, Server, ClientCall, ServerCall)
+                             -> ((Client, Server, ClientCall,
+                                  ServerCall ByteString)
                                  -> IO (Either GRPCIOError a))
                              -> IO (Either GRPCIOError a)
 withClientServerUnaryCall grpc f = do
   withClient grpc clientConf $ \c -> do
-    crm <- clientRegisterMethod c "/foo" Normal
+    crm <- clientRegisterMethodNormal c "/foo"
     withServer grpc serverConf $ \s ->
       withClientCall c crm 10 $ \cc -> do
         let srm = head (normalMethods s)
@@ -61,12 +59,12 @@ withClientServerUnaryCall grpc f = do
         -- because registered methods try to do recv ops immediately when
         -- created. If later we want to send payloads or metadata, we'll need
         -- to tweak this.
-        _clientRes <- runOps (unClientCall cc) (clientCQ c) clientEmptySendOps
+        _clientRes <- runOps (unsafeCC cc) (clientCQ c) clientEmptySendOps
         withServerCall s srm $ \sc ->
           f (c, s, cc, sc)
 
 serverConf :: ServerConfig
-serverConf = ServerConfig "localhost" 50051 [("/foo", Normal)] []
+serverConf = ServerConfig "localhost" 50051 [("/foo")] [] [] [] []
 
 clientConf :: ClientConfig
 clientConf = ClientConfig "localhost" 50051 []