diff --git a/README.md b/README.md
index 7d3d8c7f..b6411537 100644
--- a/README.md
+++ b/README.md
@@ -5,11 +5,35 @@ Alpha : Ready for early adopters
 
 ## PREREQUISITES
 - `node`: This requires `node` to be installed. If you instead have the `nodejs` executable on Debian, you should install the [`nodejs-legacy`](https://packages.debian.org/sid/nodejs-legacy) package.
-- [homebrew][] on Mac OS X, [linuxbrew][] on Linux.  These simplify the installation of the gRPC C core.
+- [homebrew][] on Mac OS X.  These simplify the installation of the gRPC C core.
 
 ## INSTALLATION
-On Mac OS X, install [homebrew][]. On Linux, install [linuxbrew][].
-Run the following command to install gRPC Node.js.
+
+**Linux (Debian):**
+
+Add [Debian unstable][] to your `sources.list` file. Example:
+
+```sh
+echo "deb http://ftp.us.debian.org/debian unstable main contrib non-free" | \
+sudo tee -a /etc/apt/sources.list
+```
+
+Install the gRPC Debian package
+
+```sh
+sudo apt-get update
+sudo apt-get install libgrpc-dev
+```
+
+Install the gRPC NPM package
+
+```sh
+npm install grpc
+```
+
+**Mac OS X**
+
+Install [homebrew][]. Run the following command to install gRPC Node.js.
 ```sh
 $ curl -fsSL https://goo.gl/getgrpc | bash -s nodejs
 ```
@@ -88,5 +112,5 @@ ServerCredentials
 An object with factory methods for creating credential objects for servers.
 
 [homebrew]:http://brew.sh
-[linuxbrew]:https://github.com/Homebrew/linuxbrew#installation
 [gRPC install script]:https://raw.githubusercontent.com/grpc/homebrew-grpc/master/scripts/install
+[Debian unstable]:https://www.debian.org/releases/sid/
diff --git a/ext/call.cc b/ext/call.cc
index a79a4742..18858fa3 100644
--- a/ext/call.cc
+++ b/ext/call.cc
@@ -207,6 +207,13 @@ class SendMessageOp : public Op {
     if (!::node::Buffer::HasInstance(value)) {
       return false;
     }
+    Handle<Object> object_value = value->ToObject();
+    if (object_value->HasOwnProperty(NanNew("grpcWriteFlags"))) {
+      Handle<Value> flag_value = object_value->Get(NanNew("grpcWriteFlags"));
+      if (flag_value->IsUint32()) {
+        out->flags = flag_value->Uint32Value() & GRPC_WRITE_USED_MASK;
+      }
+    }
     out->data.send_message = BufferToByteBuffer(value);
     Persistent<Value> *handle = new Persistent<Value>();
     NanAssignPersistent(*handle, value);
@@ -457,10 +464,6 @@ void Call::Init(Handle<Object> exports) {
                           NanNew<FunctionTemplate>(GetPeer)->GetFunction());
   NanAssignPersistent(fun_tpl, tpl);
   Handle<Function> ctr = tpl->GetFunction();
-  ctr->Set(NanNew("WRITE_BUFFER_HINT"),
-           NanNew<Uint32, uint32_t>(GRPC_WRITE_BUFFER_HINT));
-  ctr->Set(NanNew("WRITE_NO_COMPRESS"),
-           NanNew<Uint32, uint32_t>(GRPC_WRITE_NO_COMPRESS));
   exports->Set(NanNew("Call"), ctr);
   constructor = new NanCallback(ctr);
 }
@@ -620,7 +623,7 @@ NAN_METHOD(Call::StartBatch) {
       call->wrapped_call, &ops[0], nops, new struct tag(
           callback, op_vector.release(), resources), NULL);
   if (error != GRPC_CALL_OK) {
-    return NanThrowError("startBatch failed", error);
+    return NanThrowError(nanErrorWithCode("startBatch failed", error));
   }
   CompletionQueueAsyncWorker::Next();
   NanReturnUndefined();
@@ -634,7 +637,7 @@ NAN_METHOD(Call::Cancel) {
   Call *call = ObjectWrap::Unwrap<Call>(args.This());
   grpc_call_error error = grpc_call_cancel(call->wrapped_call, NULL);
   if (error != GRPC_CALL_OK) {
-    return NanThrowError("cancel failed", error);
+    return NanThrowError(nanErrorWithCode("cancel failed", error));
   }
   NanReturnUndefined();
 }
diff --git a/ext/call.h b/ext/call.h
index 6acda761..ef6e5fcd 100644
--- a/ext/call.h
+++ b/ext/call.h
@@ -51,6 +51,19 @@ namespace node {
 using std::unique_ptr;
 using std::shared_ptr;
 
+/**
+ * Helper function for throwing errors with a grpc_call_error value.
+ * Modified from the answer by Gus Goose to
+ * http://stackoverflow.com/questions/31794200.
+ */
+inline v8::Local<v8::Value> nanErrorWithCode(const char *msg,
+                                             grpc_call_error code) {
+    NanEscapableScope();
+    v8::Local<v8::Object> err = NanError(msg).As<v8::Object>();
+    err->Set(NanNew("code"), NanNew<v8::Uint32>(code));
+    return NanEscapeScope(err);
+}
+
 v8::Handle<v8::Value> ParseMetadata(const grpc_metadata_array *metadata_array);
 
 class PersistentHolder {
diff --git a/ext/node_grpc.cc b/ext/node_grpc.cc
index d93dafda..0cf30da9 100644
--- a/ext/node_grpc.cc
+++ b/ext/node_grpc.cc
@@ -196,6 +196,16 @@ void InitConnectivityStateConstants(Handle<Object> exports) {
   channel_state->Set(NanNew("FATAL_FAILURE"), FATAL_FAILURE);
 }
 
+void InitWriteFlags(Handle<Object> exports) {
+  NanScope();
+  Handle<Object> write_flags = NanNew<Object>();
+  exports->Set(NanNew("writeFlags"), write_flags);
+  Handle<Value> BUFFER_HINT(NanNew<Uint32, uint32_t>(GRPC_WRITE_BUFFER_HINT));
+  write_flags->Set(NanNew("BUFFER_HINT"), BUFFER_HINT);
+  Handle<Value> NO_COMPRESS(NanNew<Uint32, uint32_t>(GRPC_WRITE_NO_COMPRESS));
+  write_flags->Set(NanNew("NO_COMPRESS"), NO_COMPRESS);
+}
+
 void init(Handle<Object> exports) {
   NanScope();
   grpc_init();
@@ -204,6 +214,7 @@ void init(Handle<Object> exports) {
   InitOpTypeConstants(exports);
   InitPropagateConstants(exports);
   InitConnectivityStateConstants(exports);
+  InitWriteFlags(exports);
 
   grpc::node::Call::Init(exports);
   grpc::node::Channel::Init(exports);
diff --git a/ext/server.cc b/ext/server.cc
index 57c43104..32a8ff55 100644
--- a/ext/server.cc
+++ b/ext/server.cc
@@ -233,7 +233,7 @@ NAN_METHOD(Server::RequestCall) {
       new struct tag(new NanCallback(args[0].As<Function>()), ops.release(),
                      shared_ptr<Resources>(nullptr)));
   if (error != GRPC_CALL_OK) {
-    return NanThrowError("requestCall failed", error);
+    return NanThrowError(nanErrorWithCode("requestCall failed", error));
   }
   CompletionQueueAsyncWorker::Next();
   NanReturnUndefined();
diff --git a/health_check/health.js b/health_check/health.js
index 87e00197..84d7e056 100644
--- a/health_check/health.js
+++ b/health_check/health.js
@@ -45,17 +45,13 @@ function HealthImplementation(statusMap) {
   this.statusMap = _.clone(statusMap);
 }
 
-HealthImplementation.prototype.setStatus = function(host, service, status) {
-  if (!this.statusMap[host]) {
-    this.statusMap[host] = {};
-  }
-  this.statusMap[host][service] = status;
+HealthImplementation.prototype.setStatus = function(service, status) {
+  this.statusMap[service] = status;
 };
 
 HealthImplementation.prototype.check = function(call, callback){
-  var host = call.request.host;
   var service = call.request.service;
-  var status = _.get(this.statusMap, [host, service], null);
+  var status = _.get(this.statusMap, service, null);
   if (status === null) {
     callback({code:grpc.status.NOT_FOUND});
   } else {
diff --git a/health_check/health.proto b/health_check/health.proto
index d31df1e0..57f4aaa9 100644
--- a/health_check/health.proto
+++ b/health_check/health.proto
@@ -32,8 +32,7 @@ syntax = "proto3";
 package grpc.health.v1alpha;
 
 message HealthCheckRequest {
-  string host = 1;
-  string service = 2;
+  string service = 1;
 }
 
 message HealthCheckResponse {
@@ -47,4 +46,4 @@ message HealthCheckResponse {
 
 service Health {
   rpc Check(HealthCheckRequest) returns (HealthCheckResponse);
-}
\ No newline at end of file
+}
diff --git a/index.js b/index.js
index 93c65ac5..889b0ac0 100644
--- a/index.js
+++ b/index.js
@@ -144,6 +144,11 @@ exports.propagate = grpc.propagate;
  */
 exports.callError = grpc.callError;
 
+/**
+ * Write flag name to code number mapping
+ */
+exports.writeFlags = grpc.writeFlags;
+
 /**
  * Credentials factories
  */
diff --git a/src/client.js b/src/client.js
index 50cbf4a1..7b7eae51 100644
--- a/src/client.js
+++ b/src/client.js
@@ -79,13 +79,19 @@ function ClientWritableStream(call, serialize) {
  * implementation of a method needed for implementing stream.Writable.
  * @access private
  * @param {Buffer} chunk The chunk to write
- * @param {string} encoding Ignored
+ * @param {string} encoding Used to pass write flags
  * @param {function(Error=)} callback Called when the write is complete
  */
 function _write(chunk, encoding, callback) {
   /* jshint validthis: true */
   var batch = {};
-  batch[grpc.opType.SEND_MESSAGE] = this.serialize(chunk);
+  var message = this.serialize(chunk);
+  if (_.isFinite(encoding)) {
+    /* Attach the encoding if it is a finite number. This is the closest we
+     * can get to checking that it is valid flags */
+    message.grpcWriteFlags = encoding;
+  }
+  batch[grpc.opType.SEND_MESSAGE] = message;
   this.call.startBatch(batch, function(err, event) {
     if (err) {
       // Something has gone wrong. Stop writing by failing to call callback
@@ -273,8 +279,12 @@ function makeUnaryRequestFunction(method, serialize, deserialize) {
         return;
       }
       var client_batch = {};
+      var message = serialize(argument);
+      if (options) {
+        message.grpcWriteFlags = options.flags;
+      }
       client_batch[grpc.opType.SEND_INITIAL_METADATA] = metadata;
-      client_batch[grpc.opType.SEND_MESSAGE] = serialize(argument);
+      client_batch[grpc.opType.SEND_MESSAGE] = message;
       client_batch[grpc.opType.SEND_CLOSE_FROM_CLIENT] = true;
       client_batch[grpc.opType.RECV_INITIAL_METADATA] = true;
       client_batch[grpc.opType.RECV_MESSAGE] = true;
@@ -407,9 +417,13 @@ function makeServerStreamRequestFunction(method, serialize, deserialize) {
         return;
       }
       var start_batch = {};
+      var message = serialize(argument);
+      if (options) {
+        message.grpcWriteFlags = options.flags;
+      }
       start_batch[grpc.opType.SEND_INITIAL_METADATA] = metadata;
       start_batch[grpc.opType.RECV_INITIAL_METADATA] = true;
-      start_batch[grpc.opType.SEND_MESSAGE] = serialize(argument);
+      start_batch[grpc.opType.SEND_MESSAGE] = message;
       start_batch[grpc.opType.SEND_CLOSE_FROM_CLIENT] = true;
       call.startBatch(start_batch, function(err, response) {
         if (err) {
diff --git a/src/server.js b/src/server.js
index f2520c3c..137f60ed 100644
--- a/src/server.js
+++ b/src/server.js
@@ -115,8 +115,10 @@ function waitForCancel(call, emitter) {
  * @param {function(*):Buffer=} serialize Serialization function for the
  *     response
  * @param {Object=} metadata Optional trailing metadata to send with status
+ * @param {number=} flags Flags for modifying how the message is sent.
+ *     Defaults to 0.
  */
-function sendUnaryResponse(call, value, serialize, metadata) {
+function sendUnaryResponse(call, value, serialize, metadata, flags) {
   var end_batch = {};
   var status = {
     code: grpc.status.OK,
@@ -130,7 +132,9 @@ function sendUnaryResponse(call, value, serialize, metadata) {
     end_batch[grpc.opType.SEND_INITIAL_METADATA] = {};
     call.metadataSent = true;
   }
-  end_batch[grpc.opType.SEND_MESSAGE] = serialize(value);
+  var message = serialize(value);
+  message.grpcWriteFlags = flags;
+  end_batch[grpc.opType.SEND_MESSAGE] = message;
   end_batch[grpc.opType.SEND_STATUS_FROM_SERVER] = status;
   call.startBatch(end_batch, function (){});
 }
@@ -254,7 +258,7 @@ function ServerWritableStream(call, serialize) {
  * for implementing stream.Writable.
  * @access private
  * @param {Buffer} chunk The chunk of data to write
- * @param {string} encoding Ignored
+ * @param {string} encoding Used to pass write flags
  * @param {function(Error=)} callback Callback to indicate that the write is
  *     complete
  */
@@ -265,7 +269,13 @@ function _write(chunk, encoding, callback) {
     batch[grpc.opType.SEND_INITIAL_METADATA] = {};
     this.call.metadataSent = true;
   }
-  batch[grpc.opType.SEND_MESSAGE] = this.serialize(chunk);
+  var message = this.serialize(chunk);
+  if (_.isFinite(encoding)) {
+    /* Attach the encoding if it is a finite number. This is the closest we
+     * can get to checking that it is valid flags */
+    message.grpcWriteFlags = encoding;
+  }
+  batch[grpc.opType.SEND_MESSAGE] = message;
   this.call.startBatch(batch, function(err, value) {
     if (err) {
       this.emit('error', err);
@@ -450,14 +460,14 @@ function handleUnary(call, handler, metadata) {
     if (emitter.cancelled) {
       return;
     }
-    handler.func(emitter, function sendUnaryData(err, value, trailer) {
+    handler.func(emitter, function sendUnaryData(err, value, trailer, flags) {
       if (err) {
         if (trailer) {
           err.metadata = trailer;
         }
         handleError(call, err);
       } else {
-        sendUnaryResponse(call, value, handler.serialize, trailer);
+        sendUnaryResponse(call, value, handler.serialize, trailer, flags);
       }
     });
   });
@@ -514,7 +524,7 @@ function handleClientStreaming(call, handler, metadata) {
   });
   waitForCancel(call, stream);
   stream.metadata = metadata;
-  handler.func(stream, function(err, value, trailer) {
+  handler.func(stream, function(err, value, trailer, flags) {
     stream.terminate();
     if (err) {
       if (trailer) {
@@ -522,7 +532,7 @@ function handleClientStreaming(call, handler, metadata) {
       }
       handleError(call, err);
     } else {
-      sendUnaryResponse(call, value, handler.serialize, trailer);
+      sendUnaryResponse(call, value, handler.serialize, trailer, flags);
     }
   });
 }
diff --git a/test/health_test.js b/test/health_test.js
index 22c58d39..9267bff7 100644
--- a/test/health_test.js
+++ b/test/health_test.js
@@ -41,13 +41,9 @@ var grpc = require('../');
 
 describe('Health Checking', function() {
   var statusMap = {
-    '': {
-      '': 'SERVING',
-      'grpc.test.TestService': 'NOT_SERVING',
-    },
-    virtual_host: {
-      'grpc.test.TestService': 'SERVING'
-    }
+    '': 'SERVING',
+    'grpc.test.TestServiceNotServing': 'NOT_SERVING',
+    'grpc.test.TestServiceServing': 'SERVING'
   };
   var healthServer = new grpc.Server();
   healthServer.addProtoService(health.service,
@@ -71,15 +67,15 @@ describe('Health Checking', function() {
     });
   });
   it('should say that a disabled service is NOT_SERVING', function(done) {
-    healthClient.check({service: 'grpc.test.TestService'},
+    healthClient.check({service: 'grpc.test.TestServiceNotServing'},
                        function(err, response) {
                          assert.ifError(err);
                          assert.strictEqual(response.status, 'NOT_SERVING');
                          done();
                        });
   });
-  it('should say that a service on another host is SERVING', function(done) {
-    healthClient.check({host: 'virtual_host', service: 'grpc.test.TestService'},
+  it('should say that an enabled service is SERVING', function(done) {
+    healthClient.check({service: 'grpc.test.TestServiceServing'},
                        function(err, response) {
                          assert.ifError(err);
                          assert.strictEqual(response.status, 'SERVING');
@@ -93,12 +89,4 @@ describe('Health Checking', function() {
       done();
     });
   });
-  it('should get NOT_FOUND if the host is not registered', function(done) {
-    healthClient.check({host: 'wrong_host', service: 'grpc.test.TestService'},
-                       function(err, response) {
-                         assert(err);
-                         assert.strictEqual(err.code, grpc.status.NOT_FOUND);
-                         done();
-                       });
-  });
 });