diff --git a/Sesame/API/DeviceResponse.swift b/Sesame/API/DeviceResponse.swift
index b5157bc..0b71b81 100644
--- a/Sesame/API/DeviceResponse.swift
+++ b/Sesame/API/DeviceResponse.swift
@@ -27,8 +27,8 @@ struct DeviceResponse {
     }
 
     /// Shorthand property for an invalid message.
-    static var invalidMessageData: DeviceResponse {
-        .init(event: .invalidMessageData)
+    static var invalidMessageSize: DeviceResponse {
+        .init(event: .invalidMessageSize)
     }
 
     /// Shorthand property for missing body data.
@@ -83,8 +83,8 @@ struct DeviceResponse {
     /// Get the reponse encoded in bytes.
     var encoded: Data {
         guard let message = response else {
-            return Data([event.rawValue])
+            return event.encoded
         }
-        return Data([event.rawValue]) + message.encoded
+        return event.encoded + message.encoded
     }
 }
diff --git a/Sesame/API/MessageResult.swift b/Sesame/API/MessageResult.swift
index 7f58703..a115ca5 100644
--- a/Sesame/API/MessageResult.swift
+++ b/Sesame/API/MessageResult.swift
@@ -11,8 +11,8 @@ enum MessageResult: UInt8 {
     /// A socket event on the device was unexpected (not binary data)
     case unexpectedSocketEvent = 2
 
-    /// The size of the payload (i.e. message) was invalid, or the data could not be read
-    case invalidMessageData = 3
+    /// The size of the payload (i.e. message) was invalid
+    case invalidMessageSize = 3
 
     /// The transmitted message could not be authenticated using the key
     case messageAuthenticationFailed = 4
@@ -44,6 +44,10 @@ enum MessageResult: UInt8 {
 
     /// The device is connected
     case deviceConnected = 15
+
+    case invalidUrlParameter = 20
+
+    case invalidResponseAuthentication = 21
 }
 
 extension MessageResult: CustomStringConvertible {
@@ -54,7 +58,7 @@ extension MessageResult: CustomStringConvertible {
             return "The device received unexpected text"
         case .unexpectedSocketEvent:
             return "Unexpected socket event for the device"
-        case .invalidMessageData:
+        case .invalidMessageSize:
             return "Invalid message data"
         case .messageAuthenticationFailed:
             return "Message authentication failed"
@@ -76,6 +80,17 @@ extension MessageResult: CustomStringConvertible {
             return "Another operation is in progress"
         case .deviceConnected:
             return "The device is connected"
+        case .invalidUrlParameter:
+            return "The url parameter could not be found"
+        case .invalidResponseAuthentication:
+            return "The response could not be authenticated"
         }
     }
 }
+
+extension MessageResult {
+
+    var encoded: Data {
+        Data([rawValue])
+    }
+}
diff --git a/Sesame/API/ServerMessage.swift b/Sesame/API/ServerMessage.swift
index 1e4dfb6..783e453 100644
--- a/Sesame/API/ServerMessage.swift
+++ b/Sesame/API/ServerMessage.swift
@@ -11,8 +11,6 @@ struct ServerMessage {
 
     static let authTokenSize = SHA256.byteCount
 
-    static let length = authTokenSize + Message.length
-
     let authToken: Data
 
     let message: Message
@@ -21,31 +19,8 @@ struct ServerMessage {
         self.authToken = authToken
         self.message = message
     }
-    
-    /**
-     Decode a message from a byte buffer.
-     The buffer must contain at least `ServerMessage.length` bytes, or it will return `nil`.
-     - Parameter buffer: The buffer containing the bytes.
-     */
-    init?(decodeFrom buffer: ByteBuffer) {
-        guard let data = buffer.getBytes(at: 0, length: ServerMessage.length) else {
-            return nil
-        }
-        self.authToken = Data(data.prefix(ServerMessage.authTokenSize))
-        self.message = Message(decodeFrom: Data(data.dropFirst(ServerMessage.authTokenSize)))
-    }
 
     var encoded: Data {
         authToken + message.encoded
     }
-
-    static func token(from buffer: ByteBuffer) -> Data? {
-        guard buffer.readableBytes == authTokenSize else {
-            return nil
-        }
-        guard let bytes = buffer.getBytes(at: 0, length: authTokenSize) else {
-            return nil
-        }
-        return Data(bytes)
-    }
 }