diff --git a/samples/Example.General/Program.cs b/samples/Example.General/Program.cs
index 27d5fd1..aed3933 100644
--- a/samples/Example.General/Program.cs
+++ b/samples/Example.General/Program.cs
@@ -41,7 +41,7 @@ class Test001 : ITest001
         public async Task<string> Login(LoginRequestMsg login) {
             Console.WriteLine($"Worker ({_uuid}) - Username: {login.Username} Password: {login.Password}");
             RpcContext context = RpcContext.Current;
-
+         
             return "Wow";
         }
 
@@ -85,8 +85,12 @@ static async Task AsyncMain(string[] args) {
                 Console.WriteLine();
             }
 
-            // detaches the service
-            await TestNode.DetachAsync(service).ConfigureAwait(false);
+            var proxy = TestNode.Proxy<ITest001>("auth:login");
+            string a = await proxy.Login(new LoginRequestMsg()
+            {
+                Username = "wow",
+                Password = "wow"
+            });
 
             await Task.Delay(50000);
         }
diff --git a/src/Holon/Holon.csproj b/src/Holon/Holon.csproj
index 6cef4bd..8deceaa 100644
--- a/src/Holon/Holon.csproj
+++ b/src/Holon/Holon.csproj
@@ -1,8 +1,8 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <TargetFramework>netstandard1.6</TargetFramework>
-    <Version>0.2.0</Version>
+    <Version>0.2.1</Version>
     <Authors>Alan Doherty</Authors>
     <Company>Alan Doherty</Company>
     <Description>A minimal service and event bus with additional support for RPC</Description>
@@ -10,11 +10,11 @@
     <PackageProjectUrl>https://github.com/alandoherty/holon-net</PackageProjectUrl>
     <RepositoryUrl>https://github.com/alandoherty/holon-net</RepositoryUrl>
     <RepositoryType>git</RepositoryType>
-    <AssemblyVersion>0.2.0.0</AssemblyVersion>
+    <AssemblyVersion>0.2.1.0</AssemblyVersion>
     <PackageLicenseUrl>https://github.com/alandoherty/holon-net/blob/master/LICENSE</PackageLicenseUrl>
     <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
     <PackageIconUrl>https://s3-eu-west-1.amazonaws.com/assets.alandoherty.co.uk/github/holon-net-nuget.png</PackageIconUrl>
-    <FileVersion>0.2.0.0</FileVersion>
+    <FileVersion>0.2.1.0</FileVersion>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
diff --git a/src/Holon/Remoting/RpcBehaviour.cs b/src/Holon/Remoting/RpcBehaviour.cs
index a9eee01..0f11f3c 100644
--- a/src/Holon/Remoting/RpcBehaviour.cs
+++ b/src/Holon/Remoting/RpcBehaviour.cs
@@ -78,9 +78,9 @@ private async Task ApplyAsync(RpcHeader header, Envelope envelope) {
                 try {
                     req = serializer.DeserializeRequest(envelope.Body, (i, o) => RpcArgument.FromMember(GetMember(i, o)));
                 } catch (KeyNotFoundException) {
-                    res = new RpcResponse("InterfaceNotFound", "The interface or operation could not be found");
+                    res = new RpcResponse("InterfaceNotFound", "The interface or operation could not be found", null);
                 } catch(Exception ex) {
-                    res = new RpcResponse("ArgumentInvalid", string.Format("The request format is invalid: {0}", ex.Message));
+                    res = new RpcResponse("ArgumentInvalid", string.Format("The request format is invalid: {0}", ex.Message), null);
                 }
 
                 // apply single request
@@ -90,7 +90,7 @@ private async Task ApplyAsync(RpcHeader header, Envelope envelope) {
                     if (req != null)
                         memberInfo = GetMember(req.Interface, req.Operation);
                 } catch (KeyNotFoundException) {
-                    res = new RpcResponse("OperationNotFound", "The interface or operation could not be found");
+                    res = new RpcResponse("OperationNotFound", "The interface or operation could not be found", null);
                 }
 
                 // get operation information
@@ -107,7 +107,7 @@ private async Task ApplyAsync(RpcHeader header, Envelope envelope) {
 
                 // check if they have a response ID if no reply isn't enabled
                 if (!noReply && envelope.ID == Guid.Empty)
-                    res = new RpcResponse("InvalidOperation", "The envelope does not specify a correlation ID");
+                    res = new RpcResponse("InvalidOperation", "The envelope does not specify a correlation ID", null);
 
                 // apply request if we don't have a response already, typically an error
                 if (res == null) {
@@ -192,7 +192,7 @@ private MemberInfo GetMember(string @interface, string operation) {
         private async Task<RpcResponse> ApplyRequestAsync(RpcRequest req, MemberInfo member) {
             // find interface behaviour
             if (!_behaviours.TryGetValue(req.Interface, out Binding binding))
-                return new RpcResponse("InterfaceNotFound", "The interface binding could not be found");
+                return new RpcResponse("InterfaceNotFound", "The interface binding could not be found", null);
             
             // get method info
             MethodInfo operationMethod = member as MethodInfo;
@@ -205,7 +205,7 @@ private async Task<RpcResponse> ApplyRequestAsync(RpcRequest req, MemberInfo mem
             for (int i = 0; i < methodArgs.Length; i++) {
                 if (!req.Arguments.TryGetValue(methodParams[i].Name, out methodArgs[i])) {
                     if (!methodParams[i].IsOptional)
-                        return new RpcResponse("ArgumentRequired", string.Format("The argument {0} is not optional", methodParams[i].Name));
+                        return new RpcResponse("ArgumentRequired", string.Format("The argument {0} is not optional", methodParams[i].Name), null);
                 }
             }
 
@@ -216,9 +216,9 @@ private async Task<RpcResponse> ApplyRequestAsync(RpcRequest req, MemberInfo mem
                 methodResult = operationMethod.Invoke(binding.Behaviour, methodArgs);
                 await ((Task)methodResult).ConfigureAwait(false);
             } catch (RpcException ex) {
-                return new RpcResponse(ex.Code, ex.Message);
+                return new RpcResponse(ex.Code, ex.Message, ex.ToString());
             } catch (Exception ex) {
-                return new RpcResponse("Exception", ex.ToString());
+                return new RpcResponse("Exception", ex.Message, ex.ToString());
             }
             
             // check if the operation returns anything
@@ -416,7 +416,7 @@ public Task<InterfaceInformation> GetInterfaceInfo(string @interface) {
 
                 lock (_behaviour._behaviours) {
                     if (!_behaviour._behaviours.TryGetValue(@interface, out binding) || !binding.AllowIntrospection)
-                        throw new RpcException("InterfaceNotFound", "The interface does not exist");
+                        throw new RpcException("InterfaceNotFound", "The interface does not exist", null);
                 }
 
                 return Task.FromResult(binding.Introspection);
diff --git a/src/Holon/Remoting/RpcError.cs b/src/Holon/Remoting/RpcError.cs
index 4d6a597..3fff115 100644
--- a/src/Holon/Remoting/RpcError.cs
+++ b/src/Holon/Remoting/RpcError.cs
@@ -12,6 +12,7 @@ public sealed class RpcError
         #region Fields
         private string _code;
         private string _message;
+        private string _details;
         #endregion
 
         #region Properties
@@ -32,6 +33,15 @@ public string Message {
                 return _message;
             }
         }
+
+        /// <summary>
+        /// Gets the error details.
+        /// </summary>
+        public string Details {
+            get {
+                return _details ?? _message;
+            }
+        }
         #endregion
 
         #region Constructors
@@ -40,9 +50,11 @@ public string Message {
         /// </summary>
         /// <param name="code">The code.</param>
         /// <param name="message">The message.</param>
-        internal RpcError(string code, string message) {
+        /// <param name="details">The details.</param>
+        internal RpcError(string code, string message, string details) {
             _code = code;
             _message = message;
+            _details = details;
         }
         #endregion
     }
diff --git a/src/Holon/Remoting/RpcException.cs b/src/Holon/Remoting/RpcException.cs
index eb8011f..1c8ff08 100644
--- a/src/Holon/Remoting/RpcException.cs
+++ b/src/Holon/Remoting/RpcException.cs
@@ -11,6 +11,7 @@ public class RpcException : Exception
     {
         #region Fields
         private string _code;
+        private string _details;
         #endregion
 
         #region Properties
@@ -22,28 +23,28 @@ public string Code {
                 return _code;
             }
         }
-        #endregion
 
-        #region Constructors
         /// <summary>
-        /// Creates a new RPC excpetion with the provided code and message.
+        /// Gets the details.
         /// </summary>
-        /// <param name="code">The code.</param>
-        /// <param name="message">The message.</param>
-        public RpcException(string code, string message)
-            : base(message) {
-            _code = code;
+        public string Details {
+            get {
+                return _details;
+            }
         }
+        #endregion
 
+        #region Constructors
         /// <summary>
-        /// Creates a new RPC exception with the provided code, message and inner exception.
+        /// Creates a new RPC excpetion with the provided code and message.
         /// </summary>
         /// <param name="code">The code.</param>
         /// <param name="message">The message.</param>
-        /// <param name="innerException">The inner exception.</param>
-        public RpcException(string code, string message, Exception innerException)
-            : base(message, innerException) {
+        /// <param name="details">The details.</param>
+        public RpcException(string code, string message, string details)
+            : base(message) {
             _code = code;
+            _details = details;
         }
 
         /// <summary>
@@ -51,16 +52,7 @@ public RpcException(string code, string message, Exception innerException)
         /// </summary>
         /// <param name="error">The error.</param>
         public RpcException(RpcError error)
-            : this(error.Code, error.Message) {
-        }
-
-        /// <summary>
-        /// Creates a new RPC exception with the RPC error object and inner exception.
-        /// </summary>
-        /// <param name="error">The error.</param>
-        /// <param name="innerException">The inner exception.</param>
-        public RpcException(RpcError error, Exception innerException)
-          : this(error.Code, error.Message, innerException) {
+            : this(error.Code, error.Message, error.Details) {
         }
         #endregion
     }
diff --git a/src/Holon/Remoting/RpcResponse.cs b/src/Holon/Remoting/RpcResponse.cs
index 8a89b98..9699802 100644
--- a/src/Holon/Remoting/RpcResponse.cs
+++ b/src/Holon/Remoting/RpcResponse.cs
@@ -70,8 +70,9 @@ internal RpcResponse(object data, Type type) {
         /// </summary>
         /// <param name="code">The code.</param>
         /// <param name="message">The message.</param>
-        internal RpcResponse(string code, string message) {
-            _error = new RpcError(code, message);
+        /// <param name="details">The details.</param>
+        internal RpcResponse(string code, string message, string details) {
+            _error = new RpcError(code, message, details);
             _data = null;
         }
 
diff --git a/src/Holon/Remoting/Serializers/ProtobufRpcSerializer.cs b/src/Holon/Remoting/Serializers/ProtobufRpcSerializer.cs
index 54eaca5..5649141 100644
--- a/src/Holon/Remoting/Serializers/ProtobufRpcSerializer.cs
+++ b/src/Holon/Remoting/Serializers/ProtobufRpcSerializer.cs
@@ -63,7 +63,7 @@ public RpcResponse DeserializeResponse(byte[] body, Type responseType) {
                 if (msg.IsSuccess)
                     return new RpcResponse(msg.Data.GetData(responseType), responseType);
                 else
-                    return new RpcResponse(msg.Error.Code, msg.Error.Message);
+                    return new RpcResponse(msg.Error.Code, msg.Error.Message, msg.Error.Details);
             }
         }
 
@@ -106,7 +106,8 @@ public byte[] SerializeResponse(RpcResponse response) {
                 } else {
                     res.Error = new ErrorMsg() {
                         Code = response.Error.Code,
-                        Message = response.Error.Message
+                        Message = response.Error.Message,
+                        Details = response.Error.Details
                     };
                 }
 
@@ -281,5 +282,8 @@ class ErrorMsg
 
         [ProtoMember(2, IsRequired = true)]
         public string Message { get; set; }
+
+        [ProtoMember(3)]
+        public string Details { get; set; }
     }
 }
diff --git a/src/Holon/Remoting/Serializers/XmlRpcSerializer.cs b/src/Holon/Remoting/Serializers/XmlRpcSerializer.cs
index 30c888e..f3eb5f7 100644
--- a/src/Holon/Remoting/Serializers/XmlRpcSerializer.cs
+++ b/src/Holon/Remoting/Serializers/XmlRpcSerializer.cs
@@ -141,12 +141,13 @@ public RpcResponse DeserializeResponse(byte[] body, Type dataType) {
                     // find the code and message
                     XElement errCode = err.Element(XName.Get("Code"));
                     XElement errMsg = err.Element(XName.Get("Message"));
+                    XElement errDetails = err.Element(XName.Get("Details"));
 
                     if (errCode == null || errMsg == null)
                         throw new InvalidDataException("Invalid XML document, error missing Code and Message elements");
 
                     // get data
-                    return new RpcResponse(errCode.Value, errMsg.Value);
+                    return new RpcResponse(errCode.Value, errMsg.Value, errDetails == null ? null : errDetails.Value);
                 }
             }
         }
@@ -223,6 +224,12 @@ public byte[] SerializeResponse(RpcResponse response) {
                     writer.WriteEndElement();
                     writer.WriteStartElement("Message");
                     writer.WriteValue(response.Error.Message);
+
+                    if (response.Error.Details != null)
+                    {
+                        writer.WriteStartElement("Details");
+                        writer.WriteValue(response.Error.Details);
+                    }
                 }
 
                 // finish document