Merge branch 'master' into node_method_name_conflicts

38 files changed, 522 insertions, 194 deletions

diff --git a/src/csharp/Grpc.Core/AsyncClientStreamingCall.cs b/src/csharp/Grpc.Core/AsyncClientStreamingCall.cs
index fb9b562c77..5646fed3d9 100644
--- a/src/csharp/Grpc.Core/AsyncClientStreamingCall.cs
+++ b/src/csharp/Grpc.Core/AsyncClientStreamingCall.cs
@@ -40,18 +40,22 @@ namespace Grpc.Core
     /// <summary>
     /// Return type for client streaming calls.
     /// </summary>
+    /// <typeparam name="TRequest">Request message type for this call.</typeparam>
+    /// <typeparam name="TResponse">Response message type for this call.</typeparam>
     public sealed class AsyncClientStreamingCall<TRequest, TResponse> : IDisposable
     {
         readonly IClientStreamWriter<TRequest> requestStream;
         readonly Task<TResponse> responseAsync;
+        readonly Task<Metadata> responseHeadersAsync;
         readonly Func<Status> getStatusFunc;
         readonly Func<Metadata> getTrailersFunc;
         readonly Action disposeAction;
 
-        public AsyncClientStreamingCall(IClientStreamWriter<TRequest> requestStream, Task<TResponse> responseAsync, Func<Status> getStatusFunc, Func<Metadata> getTrailersFunc, Action disposeAction)
+        internal AsyncClientStreamingCall(IClientStreamWriter<TRequest> requestStream, Task<TResponse> responseAsync, Task<Metadata> responseHeadersAsync, Func<Status> getStatusFunc, Func<Metadata> getTrailersFunc, Action disposeAction)
         {
             this.requestStream = requestStream;
             this.responseAsync = responseAsync;
+            this.responseHeadersAsync = responseHeadersAsync;
             this.getStatusFunc = getStatusFunc;
             this.getTrailersFunc = getTrailersFunc;
             this.disposeAction = disposeAction;
@@ -69,6 +73,17 @@ namespace Grpc.Core
         }
 
         /// <summary>
+        /// Asynchronous access to response headers.
+        /// </summary>
+        public Task<Metadata> ResponseHeadersAsync
+        {
+            get
+            {
+                return this.responseHeadersAsync;
+            }
+        }
+
+        /// <summary>
         /// Async stream to send streaming requests.
         /// </summary>
         public IClientStreamWriter<TRequest> RequestStream
diff --git a/src/csharp/Grpc.Core/AsyncDuplexStreamingCall.cs b/src/csharp/Grpc.Core/AsyncDuplexStreamingCall.cs
index 183c84216a..e75108c7e5 100644
--- a/src/csharp/Grpc.Core/AsyncDuplexStreamingCall.cs
+++ b/src/csharp/Grpc.Core/AsyncDuplexStreamingCall.cs
@@ -32,24 +32,29 @@
 #endregion
 
 using System;
+using System.Threading.Tasks;
 
 namespace Grpc.Core
 {
     /// <summary>
     /// Return type for bidirectional streaming calls.
     /// </summary>
+    /// <typeparam name="TRequest">Request message type for this call.</typeparam>
+    /// <typeparam name="TResponse">Response message type for this call.</typeparam>
     public sealed class AsyncDuplexStreamingCall<TRequest, TResponse> : IDisposable
     {
         readonly IClientStreamWriter<TRequest> requestStream;
         readonly IAsyncStreamReader<TResponse> responseStream;
+        readonly Task<Metadata> responseHeadersAsync;
         readonly Func<Status> getStatusFunc;
         readonly Func<Metadata> getTrailersFunc;
         readonly Action disposeAction;
 
-        public AsyncDuplexStreamingCall(IClientStreamWriter<TRequest> requestStream, IAsyncStreamReader<TResponse> responseStream, Func<Status> getStatusFunc, Func<Metadata> getTrailersFunc, Action disposeAction)
+        internal AsyncDuplexStreamingCall(IClientStreamWriter<TRequest> requestStream, IAsyncStreamReader<TResponse> responseStream, Task<Metadata> responseHeadersAsync, Func<Status> getStatusFunc, Func<Metadata> getTrailersFunc, Action disposeAction)
         {
             this.requestStream = requestStream;
             this.responseStream = responseStream;
+            this.responseHeadersAsync = responseHeadersAsync;
             this.getStatusFunc = getStatusFunc;
             this.getTrailersFunc = getTrailersFunc;
             this.disposeAction = disposeAction;
@@ -78,6 +83,17 @@ namespace Grpc.Core
         }
 
         /// <summary>
+        /// Asynchronous access to response headers.
+        /// </summary>
+        public Task<Metadata> ResponseHeadersAsync
+        {
+            get
+            {
+                return this.responseHeadersAsync;
+            }
+        }
+
+        /// <summary>
         /// Gets the call status if the call has already finished.
         /// Throws InvalidOperationException otherwise.
         /// </summary>
diff --git a/src/csharp/Grpc.Core/AsyncServerStreamingCall.cs b/src/csharp/Grpc.Core/AsyncServerStreamingCall.cs
index ab2049f269..f953091984 100644
--- a/src/csharp/Grpc.Core/AsyncServerStreamingCall.cs
+++ b/src/csharp/Grpc.Core/AsyncServerStreamingCall.cs
@@ -32,22 +32,26 @@
 #endregion
 
 using System;
+using System.Threading.Tasks;
 
 namespace Grpc.Core
 {
     /// <summary>
     /// Return type for server streaming calls.
     /// </summary>
+    /// <typeparam name="TResponse">Response message type for this call.</typeparam>
     public sealed class AsyncServerStreamingCall<TResponse> : IDisposable
     {
         readonly IAsyncStreamReader<TResponse> responseStream;
+        readonly Task<Metadata> responseHeadersAsync;
         readonly Func<Status> getStatusFunc;
         readonly Func<Metadata> getTrailersFunc;
         readonly Action disposeAction;
 
-        public AsyncServerStreamingCall(IAsyncStreamReader<TResponse> responseStream, Func<Status> getStatusFunc, Func<Metadata> getTrailersFunc, Action disposeAction)
+        internal AsyncServerStreamingCall(IAsyncStreamReader<TResponse> responseStream, Task<Metadata> responseHeadersAsync, Func<Status> getStatusFunc, Func<Metadata> getTrailersFunc, Action disposeAction)
         {
             this.responseStream = responseStream;
+            this.responseHeadersAsync = responseHeadersAsync;
             this.getStatusFunc = getStatusFunc;
             this.getTrailersFunc = getTrailersFunc;
             this.disposeAction = disposeAction;
@@ -65,6 +69,17 @@ namespace Grpc.Core
         }
 
         /// <summary>
+        /// Asynchronous access to response headers.
+        /// </summary>
+        public Task<Metadata> ResponseHeadersAsync
+        {
+            get
+            {
+                return this.responseHeadersAsync;
+            }
+        }
+
+        /// <summary>
         /// Gets the call status if the call has already finished.
         /// Throws InvalidOperationException otherwise.
         /// </summary>
diff --git a/src/csharp/Grpc.Core/AsyncUnaryCall.cs b/src/csharp/Grpc.Core/AsyncUnaryCall.cs
index 224e343916..97df8f5e91 100644
--- a/src/csharp/Grpc.Core/AsyncUnaryCall.cs
+++ b/src/csharp/Grpc.Core/AsyncUnaryCall.cs
@@ -40,16 +40,19 @@ namespace Grpc.Core
     /// <summary>
     /// Return type for single request - single response call.
     /// </summary>
+    /// <typeparam name="TResponse">Response message type for this call.</typeparam>
     public sealed class AsyncUnaryCall<TResponse> : IDisposable
     {
         readonly Task<TResponse> responseAsync;
+        readonly Task<Metadata> responseHeadersAsync;
         readonly Func<Status> getStatusFunc;
         readonly Func<Metadata> getTrailersFunc;
         readonly Action disposeAction;
 
-        public AsyncUnaryCall(Task<TResponse> responseAsync, Func<Status> getStatusFunc, Func<Metadata> getTrailersFunc, Action disposeAction)
+        internal AsyncUnaryCall(Task<TResponse> responseAsync, Task<Metadata> responseHeadersAsync, Func<Status> getStatusFunc, Func<Metadata> getTrailersFunc, Action disposeAction)
         {
             this.responseAsync = responseAsync;
+            this.responseHeadersAsync = responseHeadersAsync;
             this.getStatusFunc = getStatusFunc;
             this.getTrailersFunc = getTrailersFunc;
             this.disposeAction = disposeAction;
@@ -67,6 +70,17 @@ namespace Grpc.Core
         }
 
         /// <summary>
+        /// Asynchronous access to response headers.
+        /// </summary>
+        public Task<Metadata> ResponseHeadersAsync
+        {
+            get
+            {
+                return this.responseHeadersAsync;
+            }
+        }
+
+        /// <summary>
         /// Allows awaiting this object directly.
         /// </summary>
         public TaskAwaiter<TResponse> GetAwaiter()
diff --git a/src/csharp/Grpc.Core/CallInvocationDetails.cs b/src/csharp/Grpc.Core/CallInvocationDetails.cs
index 6565073fc5..8228b8f317 100644
--- a/src/csharp/Grpc.Core/CallInvocationDetails.cs
+++ b/src/csharp/Grpc.Core/CallInvocationDetails.cs
@@ -40,6 +40,8 @@ namespace Grpc.Core
     /// <summary>
     /// Details about a client-side call to be invoked.
     /// </summary>
+    /// <typeparam name="TRequest">Request message type for the call.</typeparam>
+    /// <typeparam name="TResponse">Response message type for the call.</typeparam>
     public struct CallInvocationDetails<TRequest, TResponse>
     {
         readonly Channel channel;
@@ -50,7 +52,7 @@ namespace Grpc.Core
         CallOptions options;
 
         /// <summary>
-        /// Initializes a new instance of the <see cref="Grpc.Core.CallInvocationDetails`2"/> struct.
+        /// Initializes a new instance of the <see cref="Grpc.Core.CallInvocationDetails{TRequest,TResponse}"/> struct.
         /// </summary>
         /// <param name="channel">Channel to use for this call.</param>
         /// <param name="method">Method to call.</param>
@@ -61,7 +63,7 @@ namespace Grpc.Core
         }
 
         /// <summary>
-        /// Initializes a new instance of the <see cref="Grpc.Core.CallInvocationDetails`2"/> struct.
+        /// Initializes a new instance of the <see cref="Grpc.Core.CallInvocationDetails{TRequest,TResponse}"/> struct.
         /// </summary>
         /// <param name="channel">Channel to use for this call.</param>
         /// <param name="method">Method to call.</param>
@@ -73,7 +75,7 @@ namespace Grpc.Core
         }
 
         /// <summary>
-        /// Initializes a new instance of the <see cref="Grpc.Core.CallInvocationDetails`2"/> struct.
+        /// Initializes a new instance of the <see cref="Grpc.Core.CallInvocationDetails{TRequest,TResponse}"/> struct.
         /// </summary>
         /// <param name="channel">Channel to use for this call.</param>
         /// <param name="method">Qualified method name.</param>
@@ -158,7 +160,7 @@ namespace Grpc.Core
         }
 
         /// <summary>
-        /// Returns new instance of <see cref="CallInvocationDetails"/> with
+        /// Returns new instance of <see cref="CallInvocationDetails{TRequest, TResponse}"/> with
         /// <c>Options</c> set to the value provided. Values of all other fields are preserved.
         /// </summary>
         public CallInvocationDetails<TRequest, TResponse> WithOptions(CallOptions options)
diff --git a/src/csharp/Grpc.Core/CallOptions.cs b/src/csharp/Grpc.Core/CallOptions.cs
index 3dfe80b48c..c3bc9c3156 100644
--- a/src/csharp/Grpc.Core/CallOptions.cs
+++ b/src/csharp/Grpc.Core/CallOptions.cs
@@ -118,6 +118,7 @@ namespace Grpc.Core
         /// Returns new instance of <see cref="CallOptions"/> with
         /// <c>Headers</c> set to the value provided. Values of all other fields are preserved.
         /// </summary>
+        /// <param name="headers">The headers.</param>
         public CallOptions WithHeaders(Metadata headers)
         {
             var newOptions = this;
@@ -129,6 +130,7 @@ namespace Grpc.Core
         /// Returns new instance of <see cref="CallOptions"/> with
         /// <c>Deadline</c> set to the value provided. Values of all other fields are preserved.
         /// </summary>
+        /// <param name="deadline">The deadline.</param>
         public CallOptions WithDeadline(DateTime deadline)
         {
             var newOptions = this;
@@ -140,6 +142,7 @@ namespace Grpc.Core
         /// Returns new instance of <see cref="CallOptions"/> with
         /// <c>CancellationToken</c> set to the value provided. Values of all other fields are preserved.
         /// </summary>
+        /// <param name="cancellationToken">The cancellation token.</param>
         public CallOptions WithCancellationToken(CancellationToken cancellationToken)
         {
             var newOptions = this;
diff --git a/src/csharp/Grpc.Core/Calls.cs b/src/csharp/Grpc.Core/Calls.cs
index 7067456638..94b3c2fe65 100644
--- a/src/csharp/Grpc.Core/Calls.cs
+++ b/src/csharp/Grpc.Core/Calls.cs
@@ -74,7 +74,7 @@ namespace Grpc.Core
         {
             var asyncCall = new AsyncCall<TRequest, TResponse>(call);
             var asyncResult = asyncCall.UnaryCallAsync(req);
-            return new AsyncUnaryCall<TResponse>(asyncResult, asyncCall.GetStatus, asyncCall.GetTrailers, asyncCall.Cancel);
+            return new AsyncUnaryCall<TResponse>(asyncResult, asyncCall.ResponseHeadersAsync, asyncCall.GetStatus, asyncCall.GetTrailers, asyncCall.Cancel);
         }
 
         /// <summary>
@@ -93,13 +93,14 @@ namespace Grpc.Core
             var asyncCall = new AsyncCall<TRequest, TResponse>(call);
             asyncCall.StartServerStreamingCall(req);
             var responseStream = new ClientResponseStream<TRequest, TResponse>(asyncCall);
-            return new AsyncServerStreamingCall<TResponse>(responseStream, asyncCall.GetStatus, asyncCall.GetTrailers, asyncCall.Cancel);
+            return new AsyncServerStreamingCall<TResponse>(responseStream, asyncCall.ResponseHeadersAsync, asyncCall.GetStatus, asyncCall.GetTrailers, asyncCall.Cancel);
         }
 
         /// <summary>
         /// Invokes a client streaming call asynchronously.
         /// In client streaming scenario, client sends a stream of requests and server responds with a single response.
         /// </summary>
+        /// <param name="call">The call defintion.</param>
         /// <returns>An awaitable call object providing access to the response.</returns>
         /// <typeparam name="TRequest">Type of request messages.</typeparam>
         /// <typeparam name="TResponse">The of response message.</typeparam>
@@ -110,7 +111,7 @@ namespace Grpc.Core
             var asyncCall = new AsyncCall<TRequest, TResponse>(call);
             var resultTask = asyncCall.ClientStreamingCallAsync();
             var requestStream = new ClientRequestStream<TRequest, TResponse>(asyncCall);
-            return new AsyncClientStreamingCall<TRequest, TResponse>(requestStream, resultTask, asyncCall.GetStatus, asyncCall.GetTrailers, asyncCall.Cancel);
+            return new AsyncClientStreamingCall<TRequest, TResponse>(requestStream, resultTask, asyncCall.ResponseHeadersAsync, asyncCall.GetStatus, asyncCall.GetTrailers, asyncCall.Cancel);
         }
 
         /// <summary>
@@ -130,7 +131,7 @@ namespace Grpc.Core
             asyncCall.StartDuplexStreamingCall();
             var requestStream = new ClientRequestStream<TRequest, TResponse>(asyncCall);
             var responseStream = new ClientResponseStream<TRequest, TResponse>(asyncCall);
-            return new AsyncDuplexStreamingCall<TRequest, TResponse>(requestStream, responseStream, asyncCall.GetStatus, asyncCall.GetTrailers, asyncCall.Cancel);
+            return new AsyncDuplexStreamingCall<TRequest, TResponse>(requestStream, responseStream, asyncCall.ResponseHeadersAsync, asyncCall.GetStatus, asyncCall.GetTrailers, asyncCall.Cancel);
         }
     }
 }
diff --git a/src/csharp/Grpc.Core/Channel.cs b/src/csharp/Grpc.Core/Channel.cs
index 2f8519dfa3..f1942727cd 100644
--- a/src/csharp/Grpc.Core/Channel.cs
+++ b/src/csharp/Grpc.Core/Channel.cs
@@ -43,7 +43,9 @@ using Grpc.Core.Utils;
 namespace Grpc.Core
 {
     /// <summary>
-    /// gRPC Channel
+    /// Represents a gRPC channel. Channels are an abstraction of long-lived connections to remote servers.
+    /// More client objects can reuse the same channel. Creating a channel is an expensive operation compared to invoking
+    /// a remote call so in general you should reuse a single channel for as many calls as possible.
     /// </summary>
     public class Channel
     {
@@ -58,7 +60,6 @@ namespace Grpc.Core
         readonly List<ChannelOption> options;
 
         bool shutdownRequested;
-        bool disposed;
 
         /// <summary>
         /// Creates a channel that connects to a specific host.
@@ -162,6 +163,7 @@ namespace Grpc.Core
         /// There is no need to call this explicitly unless your use case requires that.
         /// Starting an RPC on a new channel will request connection implicitly.
         /// </summary>
+        /// <param name="deadline">The deadline. <c>null</c> indicates no deadline.</param>
         public async Task ConnectAsync(DateTime? deadline = null)
         {
             var currentState = handle.CheckConnectivityState(true);
diff --git a/src/csharp/Grpc.Core/ChannelOptions.cs b/src/csharp/Grpc.Core/ChannelOptions.cs
index ad54b46ad5..f5ef63af54 100644
--- a/src/csharp/Grpc.Core/ChannelOptions.cs
+++ b/src/csharp/Grpc.Core/ChannelOptions.cs
@@ -44,9 +44,19 @@ namespace Grpc.Core
     /// </summary>
     public sealed class ChannelOption
     {
+        /// <summary>
+        /// Type of <c>ChannelOption</c>.
+        /// </summary>
         public enum OptionType
         {
+            /// <summary>
+            /// Channel option with integer value.
+            /// </summary>
             Integer,
+            
+            /// <summary>
+            /// Channel option with string value.
+            /// </summary>
             String
         }
 
@@ -79,6 +89,9 @@ namespace Grpc.Core
             this.intValue = intValue;
         }
 
+        /// <summary>
+        /// Gets the type of the <c>ChannelOption</c>.
+        /// </summary>
         public OptionType Type
         {
             get
@@ -87,6 +100,9 @@ namespace Grpc.Core
             }
         }
 
+        /// <summary>
+        /// Gets the name of the <c>ChannelOption</c>.
+        /// </summary>
         public string Name
         {
             get
@@ -95,6 +111,9 @@ namespace Grpc.Core
             }    
         }
 
+        /// <summary>
+        /// Gets the integer value the <c>ChannelOption</c>.
+        /// </summary>
         public int IntValue
         {
             get
@@ -104,6 +123,9 @@ namespace Grpc.Core
             }
         }
 
+        /// <summary>
+        /// Gets the string value the <c>ChannelOption</c>.
+        /// </summary>
         public string StringValue
         {
             get
@@ -140,7 +162,7 @@ namespace Grpc.Core
         /// <summary>Primary user agent: goes at the start of the user-agent metadata</summary>
         public const string PrimaryUserAgentString = "grpc.primary_user_agent";
 
-        /// <summary> Secondary user agent: goes at the end of the user-agent metadata</summary>
+        /// <summary>Secondary user agent: goes at the end of the user-agent metadata</summary>
         public const string SecondaryUserAgentString = "grpc.secondary_user_agent";
 
         /// <summary>
diff --git a/src/csharp/Grpc.Core/ClientBase.cs b/src/csharp/Grpc.Core/ClientBase.cs
index 903449439b..f4533e735c 100644
--- a/src/csharp/Grpc.Core/ClientBase.cs
+++ b/src/csharp/Grpc.Core/ClientBase.cs
@@ -53,6 +53,10 @@ namespace Grpc.Core
         readonly Channel channel;
         readonly string authUriBase;
 
+        /// <summary>
+        /// Initializes a new instance of <c>ClientBase</c> class.
+        /// </summary>
+        /// <param name="channel">The channel to use for remote call invocation.</param>
         public ClientBase(Channel channel)
         {
             this.channel = channel;
@@ -95,6 +99,11 @@ namespace Grpc.Core
         /// <summary>
         /// Creates a new call to given method.
         /// </summary>
+        /// <param name="method">The method to invoke.</param>
+        /// <param name="options">The call options.</param>
+        /// <typeparam name="TRequest">Request message type.</typeparam>
+        /// <typeparam name="TResponse">Response message type.</typeparam>
+        /// <returns>The call invocation details.</returns>
         protected CallInvocationDetails<TRequest, TResponse> CreateCall<TRequest, TResponse>(Method<TRequest, TResponse> method, CallOptions options)
             where TRequest : class
             where TResponse : class
diff --git a/src/csharp/Grpc.Core/ContextPropagationToken.cs b/src/csharp/Grpc.Core/ContextPropagationToken.cs
index a5bf1b5a70..1d899b97fd 100644
--- a/src/csharp/Grpc.Core/ContextPropagationToken.cs
+++ b/src/csharp/Grpc.Core/ContextPropagationToken.cs
@@ -44,8 +44,8 @@ namespace Grpc.Core
     /// In situations when a backend is making calls to another backend,
     /// it makes sense to propagate properties like deadline and cancellation 
     /// token of the server call to the child call.
-    /// C core provides some other contexts (like tracing context) that
-    /// are not accessible to C# layer, but this token still allows propagating them.
+    /// The gRPC native layer provides some other contexts (like tracing context) that
+    /// are not accessible to explicitly C# layer, but this token still allows propagating them.
     /// </summary>
     public class ContextPropagationToken
     {
@@ -143,13 +143,13 @@ namespace Grpc.Core
             this.propagateCancellation = propagateCancellation;
         }
             
-        /// <value><c>true</c> if parent call's deadline should be propagated to the child call.</value>
+        /// <summary><c>true</c> if parent call's deadline should be propagated to the child call.</summary>
         public bool IsPropagateDeadline
         {
             get { return this.propagateDeadline; }
         }
 
-        /// <value><c>true</c> if parent call's cancellation token should be propagated to the child call.</value>
+        /// <summary><c>true</c> if parent call's cancellation token should be propagated to the child call.</summary>
         public bool IsPropagateCancellation
         {
             get { return this.propagateCancellation; }
diff --git a/src/csharp/Grpc.Core/Grpc.Core.csproj b/src/csharp/Grpc.Core/Grpc.Core.csproj
index 055aff1444..ad2af17bc7 100644
--- a/src/csharp/Grpc.Core/Grpc.Core.csproj
+++ b/src/csharp/Grpc.Core/Grpc.Core.csproj
@@ -49,6 +49,7 @@
     <Compile Include="AsyncDuplexStreamingCall.cs" />
     <Compile Include="AsyncServerStreamingCall.cs" />
     <Compile Include="IClientStreamWriter.cs" />
+    <Compile Include="Internal\INativeCall.cs" />
     <Compile Include="IServerStreamWriter.cs" />
     <Compile Include="IAsyncStreamWriter.cs" />
     <Compile Include="IAsyncStreamReader.cs" />
diff --git a/src/csharp/Grpc.Core/GrpcEnvironment.cs b/src/csharp/Grpc.Core/GrpcEnvironment.cs
index 0a44eead74..e7c04185c2 100644
--- a/src/csharp/Grpc.Core/GrpcEnvironment.cs
+++ b/src/csharp/Grpc.Core/GrpcEnvironment.cs
@@ -102,6 +102,14 @@ namespace Grpc.Core
             }
         }
 
+        internal static int GetRefCount()
+        {
+            lock (staticLock)
+            {
+                return refCount;
+            }
+        }
+
         /// <summary>
         /// Gets application-wide logger used by gRPC.
         /// </summary>
@@ -177,7 +185,6 @@ namespace Grpc.Core
             return Marshal.PtrToStringAnsi(ptr);
         }
 
-
         internal static void GrpcNativeInit()
         {
             grpcsharp_init();
diff --git a/src/csharp/Grpc.Core/IAsyncStreamReader.cs b/src/csharp/Grpc.Core/IAsyncStreamReader.cs
index c0a0674e50..49e1ea7832 100644
--- a/src/csharp/Grpc.Core/IAsyncStreamReader.cs
+++ b/src/csharp/Grpc.Core/IAsyncStreamReader.cs
@@ -42,7 +42,7 @@ namespace Grpc.Core
     /// <summary>
     /// A stream of messages to be read.
     /// </summary>
-    /// <typeparam name="T"></typeparam>
+    /// <typeparam name="T">The message type.</typeparam>
     public interface IAsyncStreamReader<T> : IAsyncEnumerator<T>
     {
         // TODO(jtattermusch): consider just using IAsyncEnumerator instead of this interface.
diff --git a/src/csharp/Grpc.Core/IAsyncStreamWriter.cs b/src/csharp/Grpc.Core/IAsyncStreamWriter.cs
index 4e2acb9c71..9c0d2d312e 100644
--- a/src/csharp/Grpc.Core/IAsyncStreamWriter.cs
+++ b/src/csharp/Grpc.Core/IAsyncStreamWriter.cs
@@ -42,7 +42,7 @@ namespace Grpc.Core
     /// <summary>
     /// A writable stream of messages.
     /// </summary>
-    /// <typeparam name="T"></typeparam>
+    /// <typeparam name="T">The message type.</typeparam>
     public interface IAsyncStreamWriter<T>
     {
         /// <summary>
@@ -56,7 +56,7 @@ namespace Grpc.Core
         /// If null, default options will be used.
         /// Once set, this property maintains its value across subsequent
         /// writes.
-        /// <value>The write options.</value>
+        /// </summary>
         WriteOptions WriteOptions { get; set; }
     }
 }
diff --git a/src/csharp/Grpc.Core/IClientStreamWriter.cs b/src/csharp/Grpc.Core/IClientStreamWriter.cs
index a3028bc374..3fd0774db5 100644
--- a/src/csharp/Grpc.Core/IClientStreamWriter.cs
+++ b/src/csharp/Grpc.Core/IClientStreamWriter.cs
@@ -42,7 +42,7 @@ namespace Grpc.Core
     /// <summary>
     /// Client-side writable stream of messages with Close capability.
     /// </summary>
-    /// <typeparam name="T"></typeparam>
+    /// <typeparam name="T">The message type.</typeparam>
     public interface IClientStreamWriter<T> : IAsyncStreamWriter<T>
     {
         /// <summary>
diff --git a/src/csharp/Grpc.Core/Internal/AsyncCall.cs b/src/csharp/Grpc.Core/Internal/AsyncCall.cs
index bb9ba5b8dd..e3b00781c6 100644
--- a/src/csharp/Grpc.Core/Internal/AsyncCall.cs
+++ b/src/csharp/Grpc.Core/Internal/AsyncCall.cs
@@ -51,22 +51,35 @@ namespace Grpc.Core.Internal
         static readonly ILogger Logger = GrpcEnvironment.Logger.ForType<AsyncCall<TRequest, TResponse>>();
 
         readonly CallInvocationDetails<TRequest, TResponse> details;
+        readonly INativeCall injectedNativeCall;  // for testing
 
         // Completion of a pending unary response if not null.
         TaskCompletionSource<TResponse> unaryResponseTcs;
 
+        // Indicates that steaming call has finished.
+        TaskCompletionSource<object> streamingCallFinishedTcs = new TaskCompletionSource<object>();
+
+        // Response headers set here once received.
+        TaskCompletionSource<Metadata> responseHeadersTcs = new TaskCompletionSource<Metadata>();
+
         // Set after status is received. Used for both unary and streaming response calls.
         ClientSideStatus? finishedStatus;
 
-        bool readObserverCompleted;  // True if readObserver has already been completed.
-
         public AsyncCall(CallInvocationDetails<TRequest, TResponse> callDetails)
-            : base(callDetails.RequestMarshaller.Serializer, callDetails.ResponseMarshaller.Deserializer)
+            : base(callDetails.RequestMarshaller.Serializer, callDetails.ResponseMarshaller.Deserializer, callDetails.Channel.Environment)
         {
             this.details = callDetails.WithOptions(callDetails.Options.Normalize());
             this.initialMetadataSent = true;  // we always send metadata at the very beginning of the call.
         }
 
+        /// <summary>
+        /// This constructor should only be used for testing.
+        /// </summary>
+        public AsyncCall(CallInvocationDetails<TRequest, TResponse> callDetails, INativeCall injectedNativeCall) : this(callDetails)
+        {
+            this.injectedNativeCall = injectedNativeCall;
+        }
+
         // TODO: this method is not Async, so it shouldn't be in AsyncCall class, but 
         // it is reusing fair amount of code in this class, so we are leaving it here.
         /// <summary>
@@ -100,7 +113,7 @@ namespace Grpc.Core.Internal
                         bool success = (ev.success != 0);
                         try
                         {
-                            HandleUnaryResponse(success, ctx);
+                            HandleUnaryResponse(success, ctx.GetReceivedStatusOnClient(), ctx.GetReceivedMessage(), ctx.GetReceivedInitialMetadata());
                         }
                         catch (Exception e)
                         {
@@ -125,7 +138,7 @@ namespace Grpc.Core.Internal
                 Preconditions.CheckState(!started);
                 started = true;
 
-                Initialize(details.Channel.Environment.CompletionQueue);
+                Initialize(environment.CompletionQueue);
 
                 halfcloseRequested = true;
                 readingDone = true;
@@ -152,7 +165,7 @@ namespace Grpc.Core.Internal
                 Preconditions.CheckState(!started);
                 started = true;
 
-                Initialize(details.Channel.Environment.CompletionQueue);
+                Initialize(environment.CompletionQueue);
 
                 readingDone = true;
 
@@ -176,10 +189,9 @@ namespace Grpc.Core.Internal
                 Preconditions.CheckState(!started);
                 started = true;
 
-                Initialize(details.Channel.Environment.CompletionQueue);
+                Initialize(environment.CompletionQueue);
 
                 halfcloseRequested = true;
-                halfclosed = true;  // halfclose not confirmed yet, but it will be once finishedHandler is called.
 
                 byte[] payload = UnsafeSerialize(msg);
 
@@ -187,6 +199,7 @@ namespace Grpc.Core.Internal
                 {
                     call.StartServerStreaming(HandleFinished, payload, metadataArray, GetWriteFlagsForCall());
                 }
+                call.StartReceiveInitialMetadata(HandleReceivedResponseHeaders);
             }
         }
 
@@ -201,12 +214,13 @@ namespace Grpc.Core.Internal
                 Preconditions.CheckState(!started);
                 started = true;
 
-                Initialize(details.Channel.Environment.CompletionQueue);
+                Initialize(environment.CompletionQueue);
 
                 using (var metadataArray = MetadataArraySafeHandle.Create(details.Options.Headers))
                 {
                     call.StartDuplexStreaming(HandleFinished, metadataArray);
                 }
+                call.StartReceiveInitialMetadata(HandleReceivedResponseHeaders);
             }
         }
 
@@ -248,6 +262,28 @@ namespace Grpc.Core.Internal
         }
 
         /// <summary>
+        /// Get the task that completes once if streaming call finishes with ok status and throws RpcException with given status otherwise.
+        /// </summary>
+        public Task StreamingCallFinishedTask
+        {
+            get
+            {
+                return streamingCallFinishedTcs.Task;
+            }
+        }
+
+        /// <summary>
+        /// Get the task that completes once response headers are received.
+        /// </summary>
+        public Task<Metadata> ResponseHeadersAsync
+        {
+            get
+            {
+                return responseHeadersTcs.Task;
+            }
+        }
+
+        /// <summary>
         /// Gets the resulting status if the call has already finished.
         /// Throws InvalidOperationException otherwise.
         /// </summary>
@@ -281,53 +317,36 @@ namespace Grpc.Core.Internal
             }
         }
 
-        /// <summary>
-        /// On client-side, we only fire readCompletionDelegate once all messages have been read 
-        /// and status has been received.
-        /// </summary>
-        protected override void ProcessLastRead(AsyncCompletionDelegate<TResponse> completionDelegate)
+        protected override void OnAfterReleaseResources()
         {
-            if (completionDelegate != null && readingDone && finishedStatus.HasValue)
-            {
-                bool shouldComplete;
-                lock (myLock)
-                {
-                    shouldComplete = !readObserverCompleted;
-                    readObserverCompleted = true;
-                }
-
-                if (shouldComplete)
-                {
-                    var status = finishedStatus.Value.Status;
-                    if (status.StatusCode != StatusCode.OK)
-                    {
-                        FireCompletion(completionDelegate, default(TResponse), new RpcException(status));
-                    }
-                    else
-                    {
-                        FireCompletion(completionDelegate, default(TResponse), null);
-                    }
-                }
-            }
+            details.Channel.RemoveCallReference(this);
         }
 
-        protected override void OnAfterReleaseResources()
+        protected override bool IsClient
         {
-            details.Channel.RemoveCallReference(this);
+            get { return true; }
         }
 
         private void Initialize(CompletionQueueSafeHandle cq)
         {
+            var call = CreateNativeCall(cq);
+            details.Channel.AddCallReference(this);
+            InitializeInternal(call);
+            RegisterCancellationCallback();
+        }
+
+        private INativeCall CreateNativeCall(CompletionQueueSafeHandle cq)
+        {
+            if (injectedNativeCall != null)
+            {
+                return injectedNativeCall;  // allows injecting a mock INativeCall in tests.
+            }
+
             var parentCall = details.Options.PropagationToken != null ? details.Options.PropagationToken.ParentCall : CallSafeHandle.NullInstance;
 
-            var call = details.Channel.Handle.CreateCall(details.Channel.Environment.CompletionRegistry,
+            return details.Channel.Handle.CreateCall(environment.CompletionRegistry,
                 parentCall, ContextPropagationToken.DefaultMask, cq,
                 details.Method, details.Host, Timespec.FromDateTime(details.Options.Deadline.Value));
-
-            details.Channel.AddCallReference(this);
-
-            InitializeInternal(call);
-            RegisterCancellationCallback();
         }
 
         // Make sure that once cancellationToken for this call is cancelled, Cancel() will be called.
@@ -350,62 +369,69 @@ namespace Grpc.Core.Internal
         }
 
         /// <summary>
+        /// Handles receive status completion for calls with streaming response.
+        /// </summary>
+        private void HandleReceivedResponseHeaders(bool success, Metadata responseHeaders)
+        {
+            responseHeadersTcs.SetResult(responseHeaders);
+        }
+
+        /// <summary>
         /// Handler for unary response completion.
         /// </summary>
-        private void HandleUnaryResponse(bool success, BatchContextSafeHandle ctx)
+        private void HandleUnaryResponse(bool success, ClientSideStatus receivedStatus, byte[] receivedMessage, Metadata responseHeaders)
         {
-            var fullStatus = ctx.GetReceivedStatusOnClient();
+            TResponse msg = default(TResponse);
+            var deserializeException = success ? TryDeserialize(receivedMessage, out msg) : null;
 
             lock (myLock)
             {
                 finished = true;
-                finishedStatus = fullStatus;
 
-                halfclosed = true;
+                if (deserializeException != null && receivedStatus.Status.StatusCode == StatusCode.OK)
+                {
+                    receivedStatus = new ClientSideStatus(DeserializeResponseFailureStatus, receivedStatus.Trailers);
+                }
+                finishedStatus = receivedStatus;
 
                 ReleaseResourcesIfPossible();
             }
 
-            if (!success)
-            {
-                unaryResponseTcs.SetException(new RpcException(new Status(StatusCode.Internal, "Internal error occured.")));
-                return;
-            }
+            responseHeadersTcs.SetResult(responseHeaders);
 
-            var status = fullStatus.Status;
+            var status = receivedStatus.Status;
 
-            if (status.StatusCode != StatusCode.OK)
+            if (!success || status.StatusCode != StatusCode.OK)
             {
                 unaryResponseTcs.SetException(new RpcException(status));
                 return;
             }
 
-            // TODO: handle deserialization error
-            TResponse msg;
-            TryDeserialize(ctx.GetReceivedMessage(), out msg);
-
             unaryResponseTcs.SetResult(msg);
         }
 
         /// <summary>
         /// Handles receive status completion for calls with streaming response.
         /// </summary>
-        private void HandleFinished(bool success, BatchContextSafeHandle ctx)
+        private void HandleFinished(bool success, ClientSideStatus receivedStatus)
         {
-            var fullStatus = ctx.GetReceivedStatusOnClient();
-
-            AsyncCompletionDelegate<TResponse> origReadCompletionDelegate = null;
             lock (myLock)
             {
                 finished = true;
-                finishedStatus = fullStatus;
-
-                origReadCompletionDelegate = readCompletionDelegate;
+                finishedStatus = receivedStatus;
 
                 ReleaseResourcesIfPossible();
             }
 
-            ProcessLastRead(origReadCompletionDelegate);
+            var status = receivedStatus.Status;
+
+            if (!success || status.StatusCode != StatusCode.OK)
+            {
+                streamingCallFinishedTcs.SetException(new RpcException(status));
+                return;
+            }
+
+            streamingCallFinishedTcs.SetResult(null);
         }
     }
 }
\ No newline at end of file
diff --git a/src/csharp/Grpc.Core/Internal/AsyncCallBase.cs b/src/csharp/Grpc.Core/Internal/AsyncCallBase.cs
index 1808294f43..3e2c57c9b5 100644
--- a/src/csharp/Grpc.Core/Internal/AsyncCallBase.cs
+++ b/src/csharp/Grpc.Core/Internal/AsyncCallBase.cs
@@ -33,10 +33,12 @@
 
 using System;
 using System.Diagnostics;
+using System.IO;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using System.Threading;
 using System.Threading.Tasks;
+
 using Grpc.Core.Internal;
 using Grpc.Core.Logging;
 using Grpc.Core.Utils;
@@ -50,34 +52,35 @@ namespace Grpc.Core.Internal
     internal abstract class AsyncCallBase<TWrite, TRead>
     {
         static readonly ILogger Logger = GrpcEnvironment.Logger.ForType<AsyncCallBase<TWrite, TRead>>();
+        protected static readonly Status DeserializeResponseFailureStatus = new Status(StatusCode.Internal, "Failed to deserialize response message.");
 
         readonly Func<TWrite, byte[]> serializer;
         readonly Func<byte[], TRead> deserializer;
 
+        protected readonly GrpcEnvironment environment;
         protected readonly object myLock = new object();
 
-        protected CallSafeHandle call;
+        protected INativeCall call;
         protected bool disposed;
 
         protected bool started;
-        protected bool errorOccured;
         protected bool cancelRequested;
 
         protected AsyncCompletionDelegate<object> sendCompletionDelegate;  // Completion of a pending send or sendclose if not null.
         protected AsyncCompletionDelegate<TRead> readCompletionDelegate;  // Completion of a pending send or sendclose if not null.
 
-        protected bool readingDone;
-        protected bool halfcloseRequested;
-        protected bool halfclosed;
+        protected bool readingDone;  // True if last read (i.e. read with null payload) was already received.
+        protected bool halfcloseRequested;  // True if send close have been initiated.
         protected bool finished;  // True if close has been received from the peer.
 
         protected bool initialMetadataSent;
-        protected long streamingWritesCounter;
+        protected long streamingWritesCounter;  // Number of streaming send operations started so far.
 
-        public AsyncCallBase(Func<TWrite, byte[]> serializer, Func<byte[], TRead> deserializer)
+        public AsyncCallBase(Func<TWrite, byte[]> serializer, Func<byte[], TRead> deserializer, GrpcEnvironment environment)
         {
             this.serializer = Preconditions.CheckNotNull(serializer);
             this.deserializer = Preconditions.CheckNotNull(deserializer);
+            this.environment = Preconditions.CheckNotNull(environment);
         }
 
         /// <summary>
@@ -100,11 +103,10 @@ namespace Grpc.Core.Internal
         /// <summary>
         /// Requests cancelling the call with given status.
         /// </summary>
-        public void CancelWithStatus(Status status)
+        protected void CancelWithStatus(Status status)
         {
             lock (myLock)
             {
-                Preconditions.CheckState(started);
                 cancelRequested = true;
 
                 if (!disposed)
@@ -114,7 +116,7 @@ namespace Grpc.Core.Internal
             }
         }
 
-        protected void InitializeInternal(CallSafeHandle call)
+        protected void InitializeInternal(INativeCall call)
         {
             lock (myLock)
             {
@@ -159,16 +161,6 @@ namespace Grpc.Core.Internal
             }
         }
 
-        // TODO(jtattermusch): find more fitting name for this method.
-        /// <summary>
-        /// Default behavior just completes the read observer, but more sofisticated behavior might be required
-        /// by subclasses.
-        /// </summary>
-        protected virtual void ProcessLastRead(AsyncCompletionDelegate<TRead> completionDelegate)
-        {
-            FireCompletion(completionDelegate, default(TRead), null);
-        }
-
         /// <summary>
         /// If there are no more pending actions and no new actions can be started, releases
         /// the underlying native resources.
@@ -177,7 +169,7 @@ namespace Grpc.Core.Internal
         {
             if (!disposed && call != null)
             {
-                bool noMoreSendCompletions = halfclosed || (cancelRequested && sendCompletionDelegate == null);
+                bool noMoreSendCompletions = sendCompletionDelegate == null && (halfcloseRequested || cancelRequested || finished);
                 if (noMoreSendCompletions && readingDone && finished)
                 {
                     ReleaseResources();
@@ -187,6 +179,11 @@ namespace Grpc.Core.Internal
             return false;
         }
 
+        protected abstract bool IsClient
+        {
+            get;
+        }
+
         private void ReleaseResources()
         {
             if (call != null)
@@ -204,11 +201,11 @@ namespace Grpc.Core.Internal
         protected void CheckSendingAllowed()
         {
             Preconditions.CheckState(started);
-            Preconditions.CheckState(!errorOccured);
             CheckNotCancelled();
             Preconditions.CheckState(!disposed);
 
             Preconditions.CheckState(!halfcloseRequested, "Already halfclosed.");
+            Preconditions.CheckState(!finished, "Already finished.");
             Preconditions.CheckState(sendCompletionDelegate == null, "Only one write can be pending at a time");
         }
 
@@ -216,7 +213,6 @@ namespace Grpc.Core.Internal
         {
             Preconditions.CheckState(started);
             Preconditions.CheckState(!disposed);
-            Preconditions.CheckState(!errorOccured);
 
             Preconditions.CheckState(!readingDone, "Stream has already been closed.");
             Preconditions.CheckState(readCompletionDelegate == null, "Only one read can be pending at a time");
@@ -235,33 +231,31 @@ namespace Grpc.Core.Internal
             return serializer(msg);
         }
 
-        protected bool TrySerialize(TWrite msg, out byte[] payload)
+        protected Exception TrySerialize(TWrite msg, out byte[] payload)
         {
             try
             {
                 payload = serializer(msg);
-                return true;
+                return null;
             }
             catch (Exception e)
             {
-                Logger.Error(e, "Exception occured while trying to serialize message");
                 payload = null;
-                return false;
+                return e;
             }
         }
 
-        protected bool TryDeserialize(byte[] payload, out TRead msg)
+        protected Exception TryDeserialize(byte[] payload, out TRead msg)
         {
             try
             {
                 msg = deserializer(payload);
-                return true;
+                return null;
             } 
             catch (Exception e)
             {
-                Logger.Error(e, "Exception occured while trying to deserialize message.");
                 msg = default(TRead);
-                return false;
+                return e;
             }
         }
 
@@ -280,7 +274,7 @@ namespace Grpc.Core.Internal
         /// <summary>
         /// Handles send completion.
         /// </summary>
-        protected void HandleSendFinished(bool success, BatchContextSafeHandle ctx)
+        protected void HandleSendFinished(bool success)
         {
             AsyncCompletionDelegate<object> origCompletionDelegate = null;
             lock (myLock)
@@ -304,12 +298,11 @@ namespace Grpc.Core.Internal
         /// <summary>
         /// Handles halfclose completion.
         /// </summary>
-        protected void HandleHalfclosed(bool success, BatchContextSafeHandle ctx)
+        protected void HandleHalfclosed(bool success)
         {
             AsyncCompletionDelegate<object> origCompletionDelegate = null;
             lock (myLock)
             {
-                halfclosed = true;
                 origCompletionDelegate = sendCompletionDelegate;
                 sendCompletionDelegate = null;
 
@@ -329,43 +322,40 @@ namespace Grpc.Core.Internal
         /// <summary>
         /// Handles streaming read completion.
         /// </summary>
-        protected void HandleReadFinished(bool success, BatchContextSafeHandle ctx)
+        protected void HandleReadFinished(bool success, byte[] receivedMessage)
         {
-            var payload = ctx.GetReceivedMessage();
+            TRead msg = default(TRead);
+            var deserializeException = (success && receivedMessage != null) ? TryDeserialize(receivedMessage, out msg) : null;
 
             AsyncCompletionDelegate<TRead> origCompletionDelegate = null;
             lock (myLock)
             {
                 origCompletionDelegate = readCompletionDelegate;
-                if (payload != null)
+                readCompletionDelegate = null;
+
+                if (receivedMessage == null)
                 {
-                    readCompletionDelegate = null;
+                    // This was the last read.
+                    readingDone = true;
                 }
-                else
+
+                if (deserializeException != null && IsClient)
                 {
-                    // This was the last read. Keeping the readCompletionDelegate
-                    // to be either fired by this handler or by client-side finished
-                    // handler.
                     readingDone = true;
+                    CancelWithStatus(DeserializeResponseFailureStatus);
                 }
 
                 ReleaseResourcesIfPossible();
             }
 
-            // TODO: handle the case when error occured...
+            // TODO: handle the case when success==false
 
-            if (payload != null)
-            {
-                // TODO: handle deserialization error
-                TRead msg;
-                TryDeserialize(payload, out msg);
-
-                FireCompletion(origCompletionDelegate, msg, null);
-            }
-            else
+            if (deserializeException != null && !IsClient)
             {
-                ProcessLastRead(origCompletionDelegate);
+                FireCompletion(origCompletionDelegate, default(TRead), new IOException("Failed to deserialize request message.", deserializeException));
+                return;
             }
+            FireCompletion(origCompletionDelegate, msg, null);
         }
     }
 }
\ No newline at end of file
diff --git a/src/csharp/Grpc.Core/Internal/AsyncCallServer.cs b/src/csharp/Grpc.Core/Internal/AsyncCallServer.cs
index 6278c0191e..46ca459349 100644
--- a/src/csharp/Grpc.Core/Internal/AsyncCallServer.cs
+++ b/src/csharp/Grpc.Core/Internal/AsyncCallServer.cs
@@ -49,12 +49,10 @@ namespace Grpc.Core.Internal
     {
         readonly TaskCompletionSource<object> finishedServersideTcs = new TaskCompletionSource<object>();
         readonly CancellationTokenSource cancellationTokenSource = new CancellationTokenSource();
-        readonly GrpcEnvironment environment;
         readonly Server server;
 
-        public AsyncCallServer(Func<TResponse, byte[]> serializer, Func<byte[], TRequest> deserializer, GrpcEnvironment environment, Server server) : base(serializer, deserializer)
+        public AsyncCallServer(Func<TResponse, byte[]> serializer, Func<byte[], TRequest> deserializer, GrpcEnvironment environment, Server server) : base(serializer, deserializer, environment)
         {
-            this.environment = Preconditions.CheckNotNull(environment);
             this.server = Preconditions.CheckNotNull(server);
         }
 
@@ -171,6 +169,11 @@ namespace Grpc.Core.Internal
             }
         }
 
+        protected override bool IsClient
+        {
+            get { return false; }
+        }
+
         protected override void CheckReadingAllowed()
         {
             base.CheckReadingAllowed();
@@ -185,10 +188,8 @@ namespace Grpc.Core.Internal
         /// <summary>
         /// Handles the server side close completion.
         /// </summary>
-        private void HandleFinishedServerside(bool success, BatchContextSafeHandle ctx)
+        private void HandleFinishedServerside(bool success, bool cancelled)
         {
-            bool cancelled = ctx.GetReceivedCloseOnServerCancelled();
-
             lock (myLock)
             {
                 finished = true;
diff --git a/src/csharp/Grpc.Core/Internal/CallSafeHandle.cs b/src/csharp/Grpc.Core/Internal/CallSafeHandle.cs
index 3cb01e29bd..c3611a7761 100644
--- a/src/csharp/Grpc.Core/Internal/CallSafeHandle.cs
+++ b/src/csharp/Grpc.Core/Internal/CallSafeHandle.cs
@@ -38,9 +38,9 @@ using Grpc.Core.Utils;
 namespace Grpc.Core.Internal
 {
     /// <summary>
-    /// grpc_call from <grpc/grpc.h>
+    /// grpc_call from <c>grpc/grpc.h</c>
     /// </summary>
-    internal class CallSafeHandle : SafeHandleZeroIsInvalid
+    internal class CallSafeHandle : SafeHandleZeroIsInvalid, INativeCall
     {
         public static readonly CallSafeHandle NullInstance = new CallSafeHandle();
 
@@ -87,6 +87,10 @@ namespace Grpc.Core.Internal
             BatchContextSafeHandle ctx);
 
         [DllImport("grpc_csharp_ext.dll")]
+        static extern GRPCCallError grpcsharp_call_recv_initial_metadata(CallSafeHandle call,
+            BatchContextSafeHandle ctx);
+
+        [DllImport("grpc_csharp_ext.dll")]
         static extern GRPCCallError grpcsharp_call_start_serverside(CallSafeHandle call,
             BatchContextSafeHandle ctx);
 
@@ -109,10 +113,10 @@ namespace Grpc.Core.Internal
             this.completionRegistry = completionRegistry;
         }
 
-        public void StartUnary(BatchCompletionDelegate callback, byte[] payload, MetadataArraySafeHandle metadataArray, WriteFlags writeFlags)
+        public void StartUnary(UnaryResponseClientHandler callback, byte[] payload, MetadataArraySafeHandle metadataArray, WriteFlags writeFlags)
         {
             var ctx = BatchContextSafeHandle.Create();
-            completionRegistry.RegisterBatchCompletion(ctx, callback);
+            completionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success, context.GetReceivedStatusOnClient(), context.GetReceivedMessage(), context.GetReceivedInitialMetadata()));
             grpcsharp_call_start_unary(this, ctx, payload, new UIntPtr((ulong)payload.Length), metadataArray, writeFlags)
                 .CheckOk();
         }
@@ -123,66 +127,73 @@ namespace Grpc.Core.Internal
                 .CheckOk();
         }
 
-        public void StartClientStreaming(BatchCompletionDelegate callback, MetadataArraySafeHandle metadataArray)
+        public void StartClientStreaming(UnaryResponseClientHandler callback, MetadataArraySafeHandle metadataArray)
         {
             var ctx = BatchContextSafeHandle.Create();
-            completionRegistry.RegisterBatchCompletion(ctx, callback);
+            completionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success, context.GetReceivedStatusOnClient(), context.GetReceivedMessage(), context.GetReceivedInitialMetadata()));
             grpcsharp_call_start_client_streaming(this, ctx, metadataArray).CheckOk();
         }
 
-        public void StartServerStreaming(BatchCompletionDelegate callback, byte[] payload, MetadataArraySafeHandle metadataArray, WriteFlags writeFlags)
+        public void StartServerStreaming(ReceivedStatusOnClientHandler callback, byte[] payload, MetadataArraySafeHandle metadataArray, WriteFlags writeFlags)
         {
             var ctx = BatchContextSafeHandle.Create();
-            completionRegistry.RegisterBatchCompletion(ctx, callback);
+            completionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success, context.GetReceivedStatusOnClient()));
             grpcsharp_call_start_server_streaming(this, ctx, payload, new UIntPtr((ulong)payload.Length), metadataArray, writeFlags).CheckOk();
         }
 
-        public void StartDuplexStreaming(BatchCompletionDelegate callback, MetadataArraySafeHandle metadataArray)
+        public void StartDuplexStreaming(ReceivedStatusOnClientHandler callback, MetadataArraySafeHandle metadataArray)
         {
             var ctx = BatchContextSafeHandle.Create();
-            completionRegistry.RegisterBatchCompletion(ctx, callback);
+            completionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success, context.GetReceivedStatusOnClient()));
             grpcsharp_call_start_duplex_streaming(this, ctx, metadataArray).CheckOk();
         }
 
-        public void StartSendMessage(BatchCompletionDelegate callback, byte[] payload, WriteFlags writeFlags, bool sendEmptyInitialMetadata)
+        public void StartSendMessage(SendCompletionHandler callback, byte[] payload, WriteFlags writeFlags, bool sendEmptyInitialMetadata)
         {
             var ctx = BatchContextSafeHandle.Create();
-            completionRegistry.RegisterBatchCompletion(ctx, callback);
+            completionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success));
             grpcsharp_call_send_message(this, ctx, payload, new UIntPtr((ulong)payload.Length), writeFlags, sendEmptyInitialMetadata).CheckOk();
         }
 
-        public void StartSendCloseFromClient(BatchCompletionDelegate callback)
+        public void StartSendCloseFromClient(SendCompletionHandler callback)
         {
             var ctx = BatchContextSafeHandle.Create();
-            completionRegistry.RegisterBatchCompletion(ctx, callback);
+            completionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success));
             grpcsharp_call_send_close_from_client(this, ctx).CheckOk();
         }
 
-        public void StartSendStatusFromServer(BatchCompletionDelegate callback, Status status, MetadataArraySafeHandle metadataArray, bool sendEmptyInitialMetadata)
+        public void StartSendStatusFromServer(SendCompletionHandler callback, Status status, MetadataArraySafeHandle metadataArray, bool sendEmptyInitialMetadata)
         {
             var ctx = BatchContextSafeHandle.Create();
-            completionRegistry.RegisterBatchCompletion(ctx, callback);
+            completionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success));
             grpcsharp_call_send_status_from_server(this, ctx, status.StatusCode, status.Detail, metadataArray, sendEmptyInitialMetadata).CheckOk();
         }
 
-        public void StartReceiveMessage(BatchCompletionDelegate callback)
+        public void StartReceiveMessage(ReceivedMessageHandler callback)
         {
             var ctx = BatchContextSafeHandle.Create();
-            completionRegistry.RegisterBatchCompletion(ctx, callback);
+            completionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success, context.GetReceivedMessage()));
             grpcsharp_call_recv_message(this, ctx).CheckOk();
         }
 
-        public void StartServerSide(BatchCompletionDelegate callback)
+        public void StartReceiveInitialMetadata(ReceivedResponseHeadersHandler callback)
+        {
+            var ctx = BatchContextSafeHandle.Create();
+            completionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success, context.GetReceivedInitialMetadata()));
+            grpcsharp_call_recv_initial_metadata(this, ctx).CheckOk();
+        }
+
+        public void StartServerSide(ReceivedCloseOnServerHandler callback)
         {
             var ctx = BatchContextSafeHandle.Create();
-            completionRegistry.RegisterBatchCompletion(ctx, callback);
+            completionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success, context.GetReceivedCloseOnServerCancelled()));
             grpcsharp_call_start_serverside(this, ctx).CheckOk();
         }
 
-        public void StartSendInitialMetadata(BatchCompletionDelegate callback, MetadataArraySafeHandle metadataArray)
+        public void StartSendInitialMetadata(SendCompletionHandler callback, MetadataArraySafeHandle metadataArray)
         {
             var ctx = BatchContextSafeHandle.Create();
-            completionRegistry.RegisterBatchCompletion(ctx, callback);
+            completionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success));
             grpcsharp_call_send_initial_metadata(this, ctx, metadataArray).CheckOk();
         }
 
diff --git a/src/csharp/Grpc.Core/Internal/ChannelArgsSafeHandle.cs b/src/csharp/Grpc.Core/Internal/ChannelArgsSafeHandle.cs
index c12aec5a3a..ea5b52374e 100644
--- a/src/csharp/Grpc.Core/Internal/ChannelArgsSafeHandle.cs
+++ b/src/csharp/Grpc.Core/Internal/ChannelArgsSafeHandle.cs
@@ -35,7 +35,7 @@ using System.Threading.Tasks;
 namespace Grpc.Core.Internal
 {
     /// <summary>
-    /// grpc_channel_args from <grpc/grpc.h>
+    /// grpc_channel_args from <c>grpc/grpc.h</c>
     /// </summary>
     internal class ChannelArgsSafeHandle : SafeHandleZeroIsInvalid
     {
diff --git a/src/csharp/Grpc.Core/Internal/ChannelSafeHandle.cs b/src/csharp/Grpc.Core/Internal/ChannelSafeHandle.cs
index 8cef566c14..7a1c6e3dac 100644
--- a/src/csharp/Grpc.Core/Internal/ChannelSafeHandle.cs
+++ b/src/csharp/Grpc.Core/Internal/ChannelSafeHandle.cs
@@ -36,7 +36,7 @@ using System.Threading.Tasks;
 namespace Grpc.Core.Internal
 {
     /// <summary>
-    /// grpc_channel from <grpc/grpc.h>
+    /// grpc_channel from <c>grpc/grpc.h</c>
     /// </summary>
     internal class ChannelSafeHandle : SafeHandleZeroIsInvalid
     {
diff --git a/src/csharp/Grpc.Core/Internal/ClientResponseStream.cs b/src/csharp/Grpc.Core/Internal/ClientResponseStream.cs
index 6c44521038..b4a7335c7c 100644
--- a/src/csharp/Grpc.Core/Internal/ClientResponseStream.cs
+++ b/src/csharp/Grpc.Core/Internal/ClientResponseStream.cs
@@ -72,7 +72,13 @@ namespace Grpc.Core.Internal
             call.StartReadMessage(taskSource.CompletionDelegate);
             var result = await taskSource.Task;
             this.current = result;
-            return result != null;
+
+            if (result == null)
+            {
+                await call.StreamingCallFinishedTask;
+                return false;
+            }
+            return true;
         }
 
         public void Dispose()
diff --git a/src/csharp/Grpc.Core/Internal/CompletionQueueSafeHandle.cs b/src/csharp/Grpc.Core/Internal/CompletionQueueSafeHandle.cs
index f64f3d4175..f7a3471bb4 100644
--- a/src/csharp/Grpc.Core/Internal/CompletionQueueSafeHandle.cs
+++ b/src/csharp/Grpc.Core/Internal/CompletionQueueSafeHandle.cs
@@ -35,7 +35,7 @@ using System.Threading.Tasks;
 namespace Grpc.Core.Internal
 {
     /// <summary>
-    /// grpc_completion_queue from <grpc/grpc.h>
+    /// grpc_completion_queue from <c>grpc/grpc.h</c>
     /// </summary>
     internal class CompletionQueueSafeHandle : SafeHandleZeroIsInvalid
     {
diff --git a/src/csharp/Grpc.Core/Internal/CredentialsSafeHandle.cs b/src/csharp/Grpc.Core/Internal/CredentialsSafeHandle.cs
index 8b4fa85e5d..feed335362 100644
--- a/src/csharp/Grpc.Core/Internal/CredentialsSafeHandle.cs
+++ b/src/csharp/Grpc.Core/Internal/CredentialsSafeHandle.cs
@@ -36,7 +36,7 @@ using System.Threading.Tasks;
 namespace Grpc.Core.Internal
 {
     /// <summary>
-    /// grpc_credentials from <grpc/grpc_security.h>
+    /// grpc_credentials from <c>grpc/grpc_security.h</c>
     /// </summary>
     internal class CredentialsSafeHandle : SafeHandleZeroIsInvalid
     {
diff --git a/src/csharp/Grpc.Core/Internal/INativeCall.cs b/src/csharp/Grpc.Core/Internal/INativeCall.cs
new file mode 100644
index 0000000000..cbef599139
--- /dev/null
+++ b/src/csharp/Grpc.Core/Internal/INativeCall.cs
@@ -0,0 +1,85 @@
+#region Copyright notice and license
+// Copyright 2015, Google Inc.
+// All rights reserved.
+// 
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+// 
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+// 
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#endregion
+
+using System;
+
+namespace Grpc.Core.Internal
+{
+    internal delegate void UnaryResponseClientHandler(bool success, ClientSideStatus receivedStatus, byte[] receivedMessage, Metadata responseHeaders);
+
+    // Received status for streaming response calls.
+    internal delegate void ReceivedStatusOnClientHandler(bool success, ClientSideStatus receivedStatus);
+
+    internal delegate void ReceivedMessageHandler(bool success, byte[] receivedMessage);
+
+    internal delegate void ReceivedResponseHeadersHandler(bool success, Metadata responseHeaders);
+
+    internal delegate void SendCompletionHandler(bool success);
+
+    internal delegate void ReceivedCloseOnServerHandler(bool success, bool cancelled);
+
+    /// <summary>
+    /// Abstraction of a native call object.
+    /// </summary>
+    internal interface INativeCall : IDisposable
+    {
+        void Cancel();
+
+        void CancelWithStatus(Grpc.Core.Status status);
+
+        string GetPeer();
+
+        void StartUnary(UnaryResponseClientHandler callback, byte[] payload, MetadataArraySafeHandle metadataArray, Grpc.Core.WriteFlags writeFlags);
+
+        void StartUnary(BatchContextSafeHandle ctx, byte[] payload, MetadataArraySafeHandle metadataArray, Grpc.Core.WriteFlags writeFlags);
+
+        void StartClientStreaming(UnaryResponseClientHandler callback, MetadataArraySafeHandle metadataArray);
+
+        void StartServerStreaming(ReceivedStatusOnClientHandler callback, byte[] payload, MetadataArraySafeHandle metadataArray, Grpc.Core.WriteFlags writeFlags);
+
+        void StartDuplexStreaming(ReceivedStatusOnClientHandler callback, MetadataArraySafeHandle metadataArray);
+
+        void StartReceiveMessage(ReceivedMessageHandler callback);
+
+        void StartReceiveInitialMetadata(ReceivedResponseHeadersHandler callback);
+
+        void StartSendInitialMetadata(SendCompletionHandler callback, MetadataArraySafeHandle metadataArray);
+
+        void StartSendMessage(SendCompletionHandler callback, byte[] payload, Grpc.Core.WriteFlags writeFlags, bool sendEmptyInitialMetadata);
+
+        void StartSendCloseFromClient(SendCompletionHandler callback);
+
+        void StartSendStatusFromServer(SendCompletionHandler callback, Grpc.Core.Status status, MetadataArraySafeHandle metadataArray, bool sendEmptyInitialMetadata);
+
+        void StartServerSide(ReceivedCloseOnServerHandler callback);
+    }
+}
diff --git a/src/csharp/Grpc.Core/Internal/MetadataArraySafeHandle.cs b/src/csharp/Grpc.Core/Internal/MetadataArraySafeHandle.cs
index 83994f6762..31b834c979 100644
--- a/src/csharp/Grpc.Core/Internal/MetadataArraySafeHandle.cs
+++ b/src/csharp/Grpc.Core/Internal/MetadataArraySafeHandle.cs
@@ -35,7 +35,7 @@ using System.Threading.Tasks;
 namespace Grpc.Core.Internal
 {
     /// <summary>
-    /// grpc_metadata_array from <grpc/grpc.h>
+    /// grpc_metadata_array from <c>grpc/grpc.h</c>
     /// </summary>
     internal class MetadataArraySafeHandle : SafeHandleZeroIsInvalid
     {
diff --git a/src/csharp/Grpc.Core/Internal/ServerCredentialsSafeHandle.cs b/src/csharp/Grpc.Core/Internal/ServerCredentialsSafeHandle.cs
index 37a4f5256b..51e352a18b 100644
--- a/src/csharp/Grpc.Core/Internal/ServerCredentialsSafeHandle.cs
+++ b/src/csharp/Grpc.Core/Internal/ServerCredentialsSafeHandle.cs
@@ -37,7 +37,7 @@ using Grpc.Core.Utils;
 namespace Grpc.Core.Internal
 {
     /// <summary>
-    /// grpc_server_credentials from <grpc/grpc_security.h>
+    /// grpc_server_credentials from <c>grpc/grpc_security.h</c>
     /// </summary>
     internal class ServerCredentialsSafeHandle : SafeHandleZeroIsInvalid
     {
diff --git a/src/csharp/Grpc.Core/Marshaller.cs b/src/csharp/Grpc.Core/Marshaller.cs
index f38cb0863f..3493d2d38f 100644
--- a/src/csharp/Grpc.Core/Marshaller.cs
+++ b/src/csharp/Grpc.Core/Marshaller.cs
@@ -39,7 +39,7 @@ namespace Grpc.Core
     /// <summary>
     /// Encapsulates the logic for serializing and deserializing messages.
     /// </summary>
-    public struct Marshaller<T>
+    public class Marshaller<T>
     {
         readonly Func<T, byte[]> serializer;
         readonly Func<byte[], T> deserializer;
diff --git a/src/csharp/Grpc.Core/Metadata.cs b/src/csharp/Grpc.Core/Metadata.cs
index a589b50caa..21bdf4f114 100644
--- a/src/csharp/Grpc.Core/Metadata.cs
+++ b/src/csharp/Grpc.Core/Metadata.cs
@@ -33,15 +33,23 @@ using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.Collections.Specialized;
+using System.Globalization;
 using System.Runtime.InteropServices;
 using System.Text;
+using System.Text.RegularExpressions;
 
 using Grpc.Core.Utils;
 
 namespace Grpc.Core
 {
     /// <summary>
-    /// Provides access to read and write metadata values to be exchanged during a call.
+    /// A collection of metadata entries that can be exchanged during a call.
+    /// gRPC supports these types of metadata:
+    /// <list type="bullet">
+    /// <item><term>Request headers</term><description>are sent by the client at the beginning of a remote call before any request messages are sent.</description></item>
+    /// <item><term>Response headers</term><description>are sent by the server at the beginning of a remote call handler before any response messages are sent.</description></item>
+    /// <item><term>Response trailers</term><description>are sent by the server at the end of a remote call along with resulting call status.</description></item>
+    /// </list>
     /// </summary>
     public sealed class Metadata : IList<Metadata.Entry>
     {
@@ -58,21 +66,19 @@ namespace Grpc.Core
         readonly List<Entry> entries;
         bool readOnly;
 
+        /// <summary>
+        /// Initializes a new instance of <c>Metadata</c>.
+        /// </summary>
         public Metadata()
         {
             this.entries = new List<Entry>();
         }
 
-        public Metadata(ICollection<Entry> entries)
-        {
-            this.entries = new List<Entry>(entries);
-        }
-
         /// <summary>
         /// Makes this object read-only.
         /// </summary>
         /// <returns>this object</returns>
-        public Metadata Freeze()
+        internal Metadata Freeze()
         {
             this.readOnly = true;
             return this;
@@ -184,6 +190,7 @@ namespace Grpc.Core
         public struct Entry
         {
             private static readonly Encoding Encoding = Encoding.ASCII;
+            private static readonly Regex ValidKeyRegex = new Regex("^[a-z0-9_-]+$");
 
             readonly string key;
             readonly string value;
@@ -197,7 +204,7 @@ namespace Grpc.Core
             }
 
             /// <summary>
-            /// Initializes a new instance of the <see cref="Grpc.Core.Metadata+Entry"/> struct with a binary value.
+            /// Initializes a new instance of the <see cref="Grpc.Core.Metadata.Entry"/> struct with a binary value.
             /// </summary>
             /// <param name="key">Metadata key, needs to have suffix indicating a binary valued metadata entry.</param>
             /// <param name="valueBytes">Value bytes.</param>
@@ -213,7 +220,7 @@ namespace Grpc.Core
             }
 
             /// <summary>
-            /// Initializes a new instance of the <see cref="Grpc.Core.Metadata+Entry"/> struct holding an ASCII value.
+            /// Initializes a new instance of the <see cref="Grpc.Core.Metadata.Entry"/> struct holding an ASCII value.
             /// </summary>
             /// <param name="key">Metadata key, must not use suffix indicating a binary valued metadata entry.</param>
             /// <param name="value">Value string. Only ASCII characters are allowed.</param>
@@ -280,7 +287,7 @@ namespace Grpc.Core
             }
 
             /// <summary>
-            /// Returns a <see cref="System.String"/> that represents the current <see cref="Grpc.Core.Metadata+Entry"/>.
+            /// Returns a <see cref="System.String"/> that represents the current <see cref="Grpc.Core.Metadata.Entry"/>.
             /// </summary>
             public override string ToString()
             {
@@ -316,7 +323,10 @@ namespace Grpc.Core
 
             private static string NormalizeKey(string key)
             {
-                return Preconditions.CheckNotNull(key, "key").ToLower();
+                var normalized = Preconditions.CheckNotNull(key, "key").ToLower(CultureInfo.InvariantCulture);
+                Preconditions.CheckArgument(ValidKeyRegex.IsMatch(normalized), 
+                    "Metadata entry key not valid. Keys can only contain lowercase alphanumeric characters, underscores and hyphens.");
+                return normalized;
             }
         }
     }
diff --git a/src/csharp/Grpc.Core/Method.cs b/src/csharp/Grpc.Core/Method.cs
index 4c53285893..99162a7d5d 100644
--- a/src/csharp/Grpc.Core/Method.cs
+++ b/src/csharp/Grpc.Core/Method.cs
@@ -84,6 +84,8 @@ namespace Grpc.Core
     /// <summary>
     /// A description of a remote method.
     /// </summary>
+    /// <typeparam name="TRequest">Request message type for this method.</typeparam>
+    /// <typeparam name="TResponse">Response message type for this method.</typeparam>
     public class Method<TRequest, TResponse> : IMethod
     {
         readonly MethodType type;
diff --git a/src/csharp/Grpc.Core/Server.cs b/src/csharp/Grpc.Core/Server.cs
index 28f1686e20..7c94d21561 100644
--- a/src/csharp/Grpc.Core/Server.cs
+++ b/src/csharp/Grpc.Core/Server.cs
@@ -44,7 +44,7 @@ using Grpc.Core.Utils;
 namespace Grpc.Core
 {
     /// <summary>
-    /// A gRPC server.
+    /// gRPC server. A single server can server arbitrary number of services and can listen on more than one ports.
     /// </summary>
     public class Server
     {
@@ -324,6 +324,9 @@ namespace Grpc.Core
                 server.AddServiceDefinitionInternal(serviceDefinition);
             }
 
+            /// <summary>
+            /// Gets enumerator for this collection.
+            /// </summary>
             public IEnumerator<ServerServiceDefinition> GetEnumerator()
             {
                 return server.serviceDefinitionsList.GetEnumerator();
@@ -369,6 +372,9 @@ namespace Grpc.Core
                 return Add(new ServerPort(host, port, credentials));
             }
 
+            /// <summary>
+            /// Gets enumerator for this collection.
+            /// </summary>
             public IEnumerator<ServerPort> GetEnumerator()
             {
                 return server.serverPortList.GetEnumerator();
diff --git a/src/csharp/Grpc.Core/ServerCallContext.cs b/src/csharp/Grpc.Core/ServerCallContext.cs
index 75d81c64f3..09a6b882a6 100644
--- a/src/csharp/Grpc.Core/ServerCallContext.cs
+++ b/src/csharp/Grpc.Core/ServerCallContext.cs
@@ -72,6 +72,13 @@ namespace Grpc.Core
             this.writeOptionsHolder = writeOptionsHolder;
         }
 
+        /// <summary>
+        /// Asynchronously sends response headers for the current call to the client. This method may only be invoked once for each call and needs to be invoked
+        /// before any response messages are written. Writing the first response message implicitly sends empty response headers if <c>WriteResponseHeadersAsync</c> haven't
+        /// been called yet.
+        /// </summary>
+        /// <param name="responseHeaders">The response headers to send.</param>
+        /// <returns>The task that finished once response headers have been written.</returns>
         public Task WriteResponseHeadersAsync(Metadata responseHeaders)
         {
             return writeHeadersFunc(responseHeaders);
@@ -186,6 +193,9 @@ namespace Grpc.Core
     /// </summary>
     public interface IHasWriteOptions
     {
+        /// <summary>
+        /// Gets or sets the write options.
+        /// </summary>
         WriteOptions WriteOptions { get; set; }
     }
 }
diff --git a/src/csharp/Grpc.Core/ServerMethods.cs b/src/csharp/Grpc.Core/ServerMethods.cs
index 1f119a80ff..728f77cde5 100644
--- a/src/csharp/Grpc.Core/ServerMethods.cs
+++ b/src/csharp/Grpc.Core/ServerMethods.cs
@@ -38,6 +38,8 @@ namespace Grpc.Core
     /// <summary>
     /// Server-side handler for unary call.
     /// </summary>
+    /// <typeparam name="TRequest">Request message type for this method.</typeparam>
+    /// <typeparam name="TResponse">Response message type for this method.</typeparam>
     public delegate Task<TResponse> UnaryServerMethod<TRequest, TResponse>(TRequest request, ServerCallContext context)
         where TRequest : class
         where TResponse : class;
@@ -45,6 +47,8 @@ namespace Grpc.Core
     /// <summary>
     /// Server-side handler for client streaming call.
     /// </summary>
+    /// <typeparam name="TRequest">Request message type for this method.</typeparam>
+    /// <typeparam name="TResponse">Response message type for this method.</typeparam>
     public delegate Task<TResponse> ClientStreamingServerMethod<TRequest, TResponse>(IAsyncStreamReader<TRequest> requestStream, ServerCallContext context)
         where TRequest : class
         where TResponse : class;
@@ -52,6 +56,8 @@ namespace Grpc.Core
     /// <summary>
     /// Server-side handler for server streaming call.
     /// </summary>
+    /// <typeparam name="TRequest">Request message type for this method.</typeparam>
+    /// <typeparam name="TResponse">Response message type for this method.</typeparam>
     public delegate Task ServerStreamingServerMethod<TRequest, TResponse>(TRequest request, IServerStreamWriter<TResponse> responseStream, ServerCallContext context)
         where TRequest : class
         where TResponse : class;
@@ -59,6 +65,8 @@ namespace Grpc.Core
     /// <summary>
     /// Server-side handler for bidi streaming call.
     /// </summary>
+    /// <typeparam name="TRequest">Request message type for this method.</typeparam>
+    /// <typeparam name="TResponse">Response message type for this method.</typeparam>
     public delegate Task DuplexStreamingServerMethod<TRequest, TResponse>(IAsyncStreamReader<TRequest> requestStream, IServerStreamWriter<TResponse> responseStream, ServerCallContext context)
         where TRequest : class
         where TResponse : class;
diff --git a/src/csharp/Grpc.Core/ServerServiceDefinition.cs b/src/csharp/Grpc.Core/ServerServiceDefinition.cs
index 94b0a320c3..deb1431ca3 100644
--- a/src/csharp/Grpc.Core/ServerServiceDefinition.cs
+++ b/src/csharp/Grpc.Core/ServerServiceDefinition.cs
@@ -40,6 +40,8 @@ namespace Grpc.Core
 {
     /// <summary>
     /// Mapping of method names to server call handlers.
+    /// Normally, the <c>ServerServiceDefinition</c> objects will be created by the <c>BindService</c> factory method 
+    /// that is part of the autogenerated code for a protocol buffers service definition.
     /// </summary>
     public class ServerServiceDefinition
     {
@@ -58,21 +60,41 @@ namespace Grpc.Core
             }
         }
 
+        /// <summary>
+        /// Creates a new builder object for <c>ServerServiceDefinition</c>.
+        /// </summary>
+        /// <param name="serviceName">The service name.</param>
+        /// <returns>The builder object.</returns>
         public static Builder CreateBuilder(string serviceName)
         {
             return new Builder(serviceName);
         }
 
+        /// <summary>
+        /// Builder class for <see cref="ServerServiceDefinition"/>.
+        /// </summary>
         public class Builder
         {
             readonly string serviceName;
             readonly Dictionary<string, IServerCallHandler> callHandlers = new Dictionary<string, IServerCallHandler>();
 
+            /// <summary>
+            /// Creates a new instance of builder.
+            /// </summary>
+            /// <param name="serviceName">The service name.</param>
             public Builder(string serviceName)
             {
                 this.serviceName = serviceName;
             }
 
+            /// <summary>
+            /// Adds a definitions for a single request - single response method.
+            /// </summary>
+            /// <typeparam name="TRequest">The request message class.</typeparam>
+            /// <typeparam name="TResponse">The response message class.</typeparam>
+            /// <param name="method">The method.</param>
+            /// <param name="handler">The method handler.</param>
+            /// <returns>This builder instance.</returns>
             public Builder AddMethod<TRequest, TResponse>(
                 Method<TRequest, TResponse> method,
                 UnaryServerMethod<TRequest, TResponse> handler)
@@ -83,6 +105,14 @@ namespace Grpc.Core
                 return this;
             }
 
+            /// <summary>
+            /// Adds a definitions for a client streaming method.
+            /// </summary>
+            /// <typeparam name="TRequest">The request message class.</typeparam>
+            /// <typeparam name="TResponse">The response message class.</typeparam>
+            /// <param name="method">The method.</param>
+            /// <param name="handler">The method handler.</param>
+            /// <returns>This builder instance.</returns>
             public Builder AddMethod<TRequest, TResponse>(
                 Method<TRequest, TResponse> method,
                 ClientStreamingServerMethod<TRequest, TResponse> handler)
@@ -93,6 +123,14 @@ namespace Grpc.Core
                 return this;
             }
 
+            /// <summary>
+            /// Adds a definitions for a server streaming method.
+            /// </summary>
+            /// <typeparam name="TRequest">The request message class.</typeparam>
+            /// <typeparam name="TResponse">The response message class.</typeparam>
+            /// <param name="method">The method.</param>
+            /// <param name="handler">The method handler.</param>
+            /// <returns>This builder instance.</returns>
             public Builder AddMethod<TRequest, TResponse>(
                 Method<TRequest, TResponse> method,
                 ServerStreamingServerMethod<TRequest, TResponse> handler)
@@ -103,6 +141,14 @@ namespace Grpc.Core
                 return this;
             }
 
+            /// <summary>
+            /// Adds a definitions for a bidirectional streaming method.
+            /// </summary>
+            /// <typeparam name="TRequest">The request message class.</typeparam>
+            /// <typeparam name="TResponse">The response message class.</typeparam>
+            /// <param name="method">The method.</param>
+            /// <param name="handler">The method handler.</param>
+            /// <returns>This builder instance.</returns>
             public Builder AddMethod<TRequest, TResponse>(
                 Method<TRequest, TResponse> method,
                 DuplexStreamingServerMethod<TRequest, TResponse> handler)
@@ -113,6 +159,10 @@ namespace Grpc.Core
                 return this;
             }
 
+            /// <summary>
+            /// Creates an immutable <c>ServerServiceDefinition</c> from this builder.
+            /// </summary>
+            /// <returns>The <c>ServerServiceDefinition</c> object.</returns>
             public ServerServiceDefinition Build()
             {
                 return new ServerServiceDefinition(callHandlers);
diff --git a/src/csharp/Grpc.Core/Utils/Preconditions.cs b/src/csharp/Grpc.Core/Utils/Preconditions.cs
index 374262f87a..a8ab603391 100644
--- a/src/csharp/Grpc.Core/Utils/Preconditions.cs
+++ b/src/csharp/Grpc.Core/Utils/Preconditions.cs
@@ -43,6 +43,7 @@ namespace Grpc.Core.Utils
         /// <summary>
         /// Throws <see cref="ArgumentException"/> if condition is false.
         /// </summary>
+        /// <param name="condition">The condition.</param>
         public static void CheckArgument(bool condition)
         {
             if (!condition)
@@ -54,6 +55,8 @@ namespace Grpc.Core.Utils
         /// <summary>
         /// Throws <see cref="ArgumentException"/> with given message if condition is false.
         /// </summary>
+        /// <param name="condition">The condition.</param>
+        /// <param name="errorMessage">The error message.</param>
         public static void CheckArgument(bool condition, string errorMessage)
         {
             if (!condition)
@@ -65,6 +68,7 @@ namespace Grpc.Core.Utils
         /// <summary>
         /// Throws <see cref="ArgumentNullException"/> if reference is null.
         /// </summary>
+        /// <param name="reference">The reference.</param>
         public static T CheckNotNull<T>(T reference)
         {
             if (reference == null)
@@ -77,6 +81,8 @@ namespace Grpc.Core.Utils
         /// <summary>
         /// Throws <see cref="ArgumentNullException"/> if reference is null.
         /// </summary>
+        /// <param name="reference">The reference.</param>
+        /// <param name="paramName">The parameter name.</param>
         public static T CheckNotNull<T>(T reference, string paramName)
         {
             if (reference == null)
@@ -89,6 +95,7 @@ namespace Grpc.Core.Utils
         /// <summary>
         /// Throws <see cref="InvalidOperationException"/> if condition is false.
         /// </summary>
+        /// <param name="condition">The condition.</param>
         public static void CheckState(bool condition)
         {
             if (!condition)
@@ -100,6 +107,8 @@ namespace Grpc.Core.Utils
         /// <summary>
         /// Throws <see cref="InvalidOperationException"/> with given message if condition is false.
         /// </summary>
+        /// <param name="condition">The condition.</param>
+        /// <param name="errorMessage">The error message.</param>
         public static void CheckState(bool condition, string errorMessage)
         {
             if (!condition)
diff --git a/src/csharp/Grpc.Core/VersionInfo.cs b/src/csharp/Grpc.Core/VersionInfo.cs
index b6dbd3b49c..eda821bc31 100644
--- a/src/csharp/Grpc.Core/VersionInfo.cs
+++ b/src/csharp/Grpc.Core/VersionInfo.cs
@@ -39,8 +39,8 @@ namespace Grpc.Core
     public static class VersionInfo
     {
         /// <summary>
-        /// Current version of gRPC
+        /// Current version of gRPC C#
         /// </summary>
-        public const string CurrentVersion = "0.6.1";
+        public const string CurrentVersion = "0.7.0";
     }
 }
diff --git a/src/csharp/Grpc.Core/WriteOptions.cs b/src/csharp/Grpc.Core/WriteOptions.cs
index 7ef3189d76..7523ada84a 100644
--- a/src/csharp/Grpc.Core/WriteOptions.cs
+++ b/src/csharp/Grpc.Core/WriteOptions.cs
@@ -66,11 +66,18 @@ namespace Grpc.Core
             
         private WriteFlags flags;
 
+        /// <summary>
+        /// Initializes a new instance of <c>WriteOptions</c> class.
+        /// </summary>
+        /// <param name="flags">The write flags.</param>
         public WriteOptions(WriteFlags flags = default(WriteFlags))
         {
             this.flags = flags;
         }
 
+        /// <summary>
+        /// Gets the write flags.
+        /// </summary>
         public WriteFlags Flags
         {
             get