diff --git a/README.md b/README.md
index 9d655d3..b5f4dab 100644
--- a/README.md
+++ b/README.md
@@ -3,7 +3,7 @@ Socket.IO-Client-Swift
 
 Socket.IO-client for Swift. Supports ws/wss connections and binary. For socket.io 1.0+ and Swift 1.1.
 
-For Swift 1.2, use the 1.2 branch. (1.2 will be merged with master once Swift 1.2 is released)
+For Swift 1.2 use the 1.2 branch.
 
 Installation
 ============
@@ -18,11 +18,12 @@ Constructor
 `init(socketURL: String, opts[String: AnyObject]? = nil)` - Constructs a new client for the given URL. opts can be omitted (will use default values.)
 Methods
 -------
-1. `socket.on(name:String, callback:((data:AnyObject?) -> Void))` - Adds a handler for an event.
-2. `socket.onMultipleItems(name:String, callback:((data:NSArray?) -> Void))` - Adds a handler for an event that           can have multiple items. Items are stored in an array.
+1. `socket.on(name:String, callback:((data:AnyObject?) -> Void)) -> SocketAckHandler` - Adds a handler for an event. Returns a SocketAckHandler which can be used to ack an event. See example.
+2. `socket.onMultipleItems(name:String, callback:((data:NSArray?) -> Void)) -> SocketAckHandler` - Adds a handler for an event that can have multiple items. Items are stored in an array. Returns a SocketAckHandler which can be used to ack an event. See example.
 3. `socket.emit(event:String, args:AnyObject...)` - Sends a message. Can send multiple args.
-4. `socket.connect()` - Establishes a connection to the server. A "connect" event is fired upon successful connection.
-5. `socket.close()` - Closes the socket. Once a socket is closed it should not be reopened.
+4. `socket.emitWithAck(event:String, args:AnyObject...) -> SocketAckHandler` - Sends a message that requests an acknoweldgement from the server. Returns a SocketAckHandler which you can use to add an onAck handler. See example.
+5. `socket.connect()` - Establishes a connection to the server. A "connect" event is fired upon successful connection.
+6. `socket.close()` - Closes the socket. Once a socket is closed it should not be reopened.
 
 Events
 ------
@@ -32,6 +33,8 @@ Events
 4. `reconnect` - Emitted when the connection is starting to reconnect.
 5. `reconnectAttempt` - Emitted when attempting to reconnect.
 
+Example
+=======
 ```swift
 // opts can be omitted, will use default values
 let socket = SocketIOClient(socketURL: "https://localhost:8080", opts: [
@@ -44,7 +47,7 @@ let socket = SocketIOClient(socketURL: "https://localhost:8080", opts: [
 // Socket Events
 socket.on("connect") {data in
     println("socket connected")
-    
+
     // Sending messages
     socket.emit("testEcho")
 
@@ -57,6 +60,18 @@ socket.on("connect") {data in
         true, ["test": "foo"], "bar")
 }
 
+// Requesting acks, and adding ack args
+socket.on("ackEvent") {data in
+    if let str = data as? String {
+        println("Got ackEvent")
+    }
+
+    socket.emitWithAck("ackTest", "test").onAck {data in
+        println(data)
+    }
+
+}.ackWith("I got your event", "dude")
+
 socket.on("disconnect") {data in
     if let reason = data as? String {
         println("Socket disconnected: \(reason)")
@@ -101,7 +116,7 @@ socket.onMultipleItems("multipleItems") {data in
         println(obj["test"])
     }
 }
-        
+
 // Recieving binary
 socket.on("dataTest") {data in
     if let data = data as? NSData {
diff --git a/SwiftIO/SocketAckHandler.swift b/SwiftIO/SocketAckHandler.swift
new file mode 100644
index 0000000..d3bfe77
--- /dev/null
+++ b/SwiftIO/SocketAckHandler.swift
@@ -0,0 +1,47 @@
+//
+//  SocketAckHandler.swift
+//  Socket.IO-Swift
+//
+//  Created by Erik Little on 2/14/15.
+
+//  Permission is hereby granted, free of charge, to any person obtaining a copy
+//  of this software and associated documentation files (the "Software"), to deal
+//  in the Software without restriction, including without limitation the rights
+//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in
+//  all copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+//  THE SOFTWARE.
+
+import Foundation
+
+typealias AckCallback = (AnyObject?) -> Void
+
+class SocketAckHandler {
+    let ackNum:Int!
+    let event:String!
+    var ackData:[AnyObject]?
+    var callback:AckCallback?
+    
+    init(event:String, ackNum:Int = 0) {
+        self.ackNum = ackNum
+        self.event = event
+    }
+    
+    func onAck(callback:AckCallback) {
+        self.callback = callback
+    }
+    
+    func ackWith(data:AnyObject...) {
+        self.ackData = data
+    }
+}
\ No newline at end of file
diff --git a/SwiftIO/SocketEvent.swift b/SwiftIO/SocketEvent.swift
index 679044b..84ee896 100644
--- a/SwiftIO/SocketEvent.swift
+++ b/SwiftIO/SocketEvent.swift
@@ -25,16 +25,20 @@
 import Foundation
 
 class SocketEvent {
+    let justAck:Bool!
+    var ack:Int?
     var args:AnyObject!
     lazy var currentPlace = 0
     lazy var datas = [NSData]()
     var event:String!
     var placeholders:Int!
     
-    init(event:String, args:AnyObject?, placeholders:Int = 0) {
+    init(event:String, args:AnyObject?, placeholders:Int = 0, ackNum:Int? = nil, justAck:Bool = false) {
         self.event = event
-        self.args = args?
+        self.args = args
         self.placeholders = placeholders
+        self.ack = ackNum
+        self.justAck = justAck
     }
     
     func addData(data:NSData) -> Bool {
@@ -62,46 +66,101 @@ class SocketEvent {
     }
     
     class func createMessageForEvent(event:String, withArgs args:[AnyObject],
-        hasBinary:Bool, withDatas datas:Int = 0, toNamespace nsp:String?) -> String {
+        hasBinary:Bool, withDatas datas:Int = 0, toNamespace nsp:String?, wantsAck ack:Int? = nil) -> String {
             
             var message:String
             var jsonSendError:NSError?
             
             if !hasBinary {
                 if nsp == nil {
-                    message = "42[\"\(event)\""
+                    if ack == nil {
+                        message = "42[\"\(event)\","
+                    } else {
+                        message = "42\(ack!)[\"\(event)\","
+                    }
                 } else {
-                    message = "42/\(nsp!),[\"\(event)\""
+                    if ack == nil {
+                        message = "42/\(nsp!),[\"\(event)\","
+                    } else {
+                        message = "42/\(nsp!),\(ack!)[\"\(event)\","
+                    }
                 }
             } else {
                 if nsp == nil {
-                    message = "45\(datas)-[\"\(event)\""
+                    if ack == nil {
+                        message = "45\(datas)-[\"\(event)\","
+                    } else {
+                        message = "45\(datas)-\(ack!)[\"\(event)\","
+                    }
                 } else {
-                    message = "45\(datas)-/\(nsp!),[\"\(event)\""
+                    if ack == nil {
+                        message = "45\(datas)-/\(nsp!),[\"\(event)\","
+                    } else {
+                        message = "45\(datas)-/\(nsp!),\(ack!)[\"\(event)\","
+                    }
                 }
             }
             
-            for arg in args {
-                message += ","
-                
-                if arg is NSDictionary || arg is [AnyObject] {
-                    let jsonSend = NSJSONSerialization.dataWithJSONObject(arg,
-                        options: NSJSONWritingOptions(0), error: &jsonSendError)
-                    let jsonString = NSString(data: jsonSend!, encoding: NSUTF8StringEncoding)
+            return self.completeMessage(message, args: args)
+    }
+    
+    class func createAck(ack:Int, withEvent event:String, withArgs args:[AnyObject],
+        withAckType ackType:Int, withNsp nsp:String, withBinary binary:Int = 0) -> String {
+            var msg:String
+            
+            if ackType == 3 {
+                if nsp == "/" {
+                    msg = "43\(ack)["
                     
-                    message += jsonString!
-                    continue
+                    return self.completeMessage(msg, args: args)
+                    
+                } else {
+                    msg = "43/\(nsp),\(ack)["
+                    
+                    return self.completeMessage(msg, args: args)
                 }
-                
-                if arg is String {
-                    message += "\"\(arg)\""
-                    continue
+            } else {
+                if nsp == "/" {
+                    msg = "46\(binary)-\(ack)["
+                    
+                    return self.completeMessage(msg, args: args)
+                    
+                } else {
+                    msg = "46\(binary)-/\(nsp),\(ack)["
+                    
+                    return self.completeMessage(msg, args: args)
                 }
+            }
+    }
+    
+    private class func completeMessage(var message:String, args:[AnyObject]) -> String {
+        var err:NSError?
+        for arg in args {
+            
+            if arg is NSDictionary || arg is [AnyObject] {
+                let jsonSend = NSJSONSerialization.dataWithJSONObject(arg,
+                    options: NSJSONWritingOptions(0), error: &err)
+                let jsonString = NSString(data: jsonSend!, encoding: NSUTF8StringEncoding)
                 
-                message += "\(arg)"
+                message += jsonString! as String
+                message += ","
+                continue
             }
             
-            return message + "]"
+            if arg is String {
+                message += "\"\(arg)\""
+                message += ","
+                continue
+            }
+            
+            message += "\(arg)"
+            message += ","
+        }
+        
+        if message != "" {
+            message.removeAtIndex(message.endIndex.predecessor())
+        }
+        return message + "]"
     }
     
     private func fillInArray(arr:NSArray) -> NSArray {
diff --git a/SwiftIO/SocketEventHandler.swift b/SwiftIO/SocketEventHandler.swift
index 8a77b1f..a13add6 100644
--- a/SwiftIO/SocketEventHandler.swift
+++ b/SwiftIO/SocketEventHandler.swift
@@ -23,20 +23,25 @@
 //  THE SOFTWARE.
 
 class SocketEventHandler {
+    let ack:SocketAckHandler!
     let event:String!
     let callback:NormalCallback?
     let callbackMult:MultipleCallback?
     var multiEvent = false
     
-    init(event:String, callback:NormalCallback) {
+    init(event:String, callback:NormalCallback, ack:SocketAckHandler) {
         self.event = event
         self.callback = callback
+        self.callbackMult = nil
+        self.ack = ack
     }
     
-    init(event:String, callback:MultipleCallback) {
+    init(event:String, callback:MultipleCallback, ack:SocketAckHandler) {
         self.event = event
         self.callbackMult = callback
+        self.callback = nil
         self.multiEvent = true
+        self.ack = ack
     }
     
     func executeCallback(item:AnyObject?, items:NSArray? = nil) {
diff --git a/SwiftIO/SocketIOClient.swift b/SwiftIO/SocketIOClient.swift
index 8c607f4..de32c7f 100644
--- a/SwiftIO/SocketIOClient.swift
+++ b/SwiftIO/SocketIOClient.swift
@@ -28,11 +28,19 @@ typealias NormalCallback = (AnyObject?) -> Void
 typealias MultipleCallback = (NSArray?) -> Void
 
 class SocketIOClient: NSObject, SRWebSocketDelegate {
-    let socketURL:String!
-    private let secure:Bool!
+    let socketURL:NSMutableString!
+    let ackQueue = dispatch_queue_create("ackQueue".cStringUsingEncoding(NSUTF8StringEncoding),
+        DISPATCH_QUEUE_SERIAL)
+    let handleQueue = dispatch_queue_create("handleQueue".cStringUsingEncoding(NSUTF8StringEncoding),
+        DISPATCH_QUEUE_SERIAL)
+    let emitQueue = dispatch_queue_create("emitQueue".cStringUsingEncoding(NSUTF8StringEncoding),
+        DISPATCH_QUEUE_SERIAL)
+    private var ackHandlers = [SocketAckHandler]()
+    private var currentAck = -1
     private var handlers = [SocketEventHandler]()
     private var lastSocketMessage:SocketEvent?
     private var pingTimer:NSTimer!
+    private var secure = false
     var closed = false
     var connected = false
     var connecting = false
@@ -45,16 +53,15 @@ class SocketIOClient: NSObject, SRWebSocketDelegate {
     var sid:String?
     
     init(socketURL:String, opts:[String: AnyObject]? = nil) {
-        super.init()
         var mutURL = RegexMutable(socketURL)
         
         if mutURL["https://"].matches().count != 0 {
             self.secure = true
-        } else {
-            self.secure = false
         }
+        
         mutURL = mutURL["http://"] ~= ""
         mutURL = mutURL["https://"] ~= ""
+        
         self.socketURL = mutURL
         
         // Set options
@@ -96,10 +103,10 @@ class SocketIOClient: NSObject, SRWebSocketDelegate {
         self.closed = false
         var endpoint:String
         
-        if self.secure! {
-            endpoint = "wss://\(self.socketURL)/socket.io/?EIO=2&transport=websocket"
+        if self.secure {
+            endpoint = "wss://\(self.socketURL)/socket.io/?transport=websocket"
         } else {
-            endpoint = "ws://\(self.socketURL)/socket.io/?EIO=2&transport=websocket"
+            endpoint = "ws://\(self.socketURL)/socket.io/?transport=websocket"
         }
         
         self.io = SRWebSocket(URL: NSURL(string: endpoint))
@@ -124,87 +131,147 @@ class SocketIOClient: NSObject, SRWebSocketDelegate {
             return
         }
         
+        dispatch_async(self.emitQueue) {[weak self] in
+            if self == nil {
+                return
+            }
+            
+            self?._emit(event, args)
+        }
+    }
+    
+    func emitWithAck(event:String, _ args:AnyObject...) -> SocketAckHandler {
+        if !self.connected {
+            return SocketAckHandler(event: "fail")
+        }
+        
+        self.currentAck++
+        let ackHandler = SocketAckHandler(event: event, ackNum: self.currentAck)
+        self.ackHandlers.append(ackHandler)
+        
+        dispatch_async(self.emitQueue) {[weak self] in
+            if self == nil {
+                return
+            }
+            
+            self?._emit(event, args, ack: true)
+        }
+        
+        return ackHandler
+    }
+    
+    private func _emit(event:String, _ args:[AnyObject], ack:Bool = false) {
         var frame:SocketEvent
         var str:String
-        var items = [AnyObject](count: args.count, repeatedValue: 1)
-        var numberOfPlaceholders = -1
-        var hasBinary = false
-        var emitDatas = [NSData]()
         
-        for i in 0..<args.count {
-            if let dict = args[i] as? NSDictionary {
-                // Check for binary data
-                let (newDict, hadBinary, binaryDatas) = SocketIOClient.parseNSDictionary(dict,
-                    placeholders: numberOfPlaceholders)
-                if hadBinary {
-                    numberOfPlaceholders = binaryDatas.count
-                    
-                    emitDatas.extend(binaryDatas)
-                    hasBinary = true
-                    items[i] = newDict
-                } else {
-                    items[i] = dict
-                }
-            } else if let arr = args[i] as? NSArray {
-                // arg is array, check for binary
-                let (replace, hadData, newDatas) = SocketIOClient.parseArray(arr,
-                    placeholders: numberOfPlaceholders)
-                
-                if hadData {
-                    hasBinary = true
-                    numberOfPlaceholders += emitDatas.count
-                    
-                    for data in newDatas {
-                        emitDatas.append(data)
-                    }
-                    
-                    items[i] = replace
-                } else {
-                    items[i] = arr
-                }
-            } else if let binaryData = args[i] as? NSData {
-                // args is just binary
-                hasBinary = true
-                let sendData = SocketIOClient.createBinaryDataForSend(binaryData)
-                
-                numberOfPlaceholders++
-                items[i] = ["_placeholder": true, "num": numberOfPlaceholders]
-                emitDatas.append(sendData)
-            } else {
-                items[i] = args[i]
-            }
+        let (items, hasBinary, emitDatas) = SocketIOClient.parseEmitArgs(args)
+        
+        if !self.connected {
+            return
         }
         
         if hasBinary {
-            str = SocketEvent.createMessageForEvent(event, withArgs: items,
-                hasBinary: true, withDatas: emitDatas.count, toNamespace: self.nsp)
+            if !ack {
+                str = SocketEvent.createMessageForEvent(event, withArgs: items,
+                    hasBinary: true, withDatas: emitDatas.count, toNamespace: self.nsp)
+            } else {
+                str = SocketEvent.createMessageForEvent(event, withArgs: items,
+                    hasBinary: true, withDatas: emitDatas.count, toNamespace: self.nsp, wantsAck: self.currentAck)
+            }
             
             self.io?.send(str)
             for data in emitDatas {
                 self.io?.send(data)
             }
         } else {
-            str = SocketEvent.createMessageForEvent(event, withArgs: items, hasBinary: false,
-                withDatas: 0, toNamespace: self.nsp)
+            if !ack {
+                str = SocketEvent.createMessageForEvent(event, withArgs: items, hasBinary: false,
+                    withDatas: 0, toNamespace: self.nsp)
+            } else {
+                str = SocketEvent.createMessageForEvent(event, withArgs: items, hasBinary: false,
+                    withDatas: 0, toNamespace: self.nsp, wantsAck: self.currentAck)
+            }
+            
             self.io?.send(str)
         }
     }
     
-    // Handles events
-    func handleEvent(#event:String, data:AnyObject?, multipleItems:Bool = false) {
-        // println("Should do event: \(event) with data: \(data)")
-        
-        for handler in self.handlers {
-            if handler.event == event {
-                if data is NSArray {
-                    handler.executeCallback(nil, items: (data as NSArray))
+    // If the server wants to know that the client received data
+    private func emitAck(ack:Int, withEvent event:String, withData data:[AnyObject]?, withAckType ackType:Int) {
+        dispatch_async(self.ackQueue) {[weak self] in
+            if self == nil || !self!.connected || data == nil {
+                return
+            }
+            
+            let (items, hasBinary, emitDatas) = SocketIOClient.parseEmitArgs(data!)
+            var str:String
+            
+            if !hasBinary {
+                if self?.nsp == nil {
+                    str = SocketEvent.createAck(ack, withEvent: event, withArgs: items,
+                        withAckType: 3, withNsp: "/")
                 } else {
-                    handler.executeCallback(data)
+                    str = SocketEvent.createAck(ack, withEvent: event, withArgs: items,
+                        withAckType: 3, withNsp: self!.nsp!)
+                }
+                
+                self?.io?.send(str)
+            } else {
+                if self?.nsp == nil {
+                    str = SocketEvent.createAck(ack, withEvent: event, withArgs: items,
+                        withAckType: 6, withNsp: "/", withBinary: emitDatas.count)
+                } else {
+                    str = SocketEvent.createAck(ack, withEvent: event, withArgs: items,
+                        withAckType: 6, withNsp: self!.nsp!, withBinary: emitDatas.count)
+                }
+                
+                self?.io?.send(str)
+                for data in emitDatas {
+                    self?.io?.send(data)
                 }
             }
         }
     }
     
+    // Called when the socket gets an ack for something it sent
+    private func handleAck(ack:Int, data:AnyObject?) {
+        for handler in self.ackHandlers {
+            if handler.ackNum == ack {
+                handler.callback?(data)
+                break
+            }
+        }
+    }
+    
+    // Handles events
+    func handleEvent(event:String, data:AnyObject?, isInternalMessage:Bool = false,
+        wantsAck ack:Int? = nil, withAckType ackType:Int = 3) {
+            // println("Should do event: \(event) with data: \(data)")
+            dispatch_async(dispatch_get_main_queue()) {
+                if !self.connected && !isInternalMessage {
+                    return
+                }
+                
+                for handler in self.handlers {
+                    if handler.event == event {
+                        if data is NSArray {
+                            handler.executeCallback(nil, items: (data as NSArray))
+                            if ack != nil {
+                                self.emitAck(ack!, withEvent: event,
+                                    withData: handler.ack.ackData, withAckType: ackType)
+                            }
+                        } else {
+                            handler.executeCallback(data)
+                            if ack != nil {
+                                self.emitAck(ack!, withEvent: event,
+                                    withData: handler.ack.ackData, withAckType: ackType)
+                            }
+                        }
+                    }
+                }
+            }
+    }
+    
     private func joinNamespace() {
         if self.nsp != nil {
             self.io?.send("40/\(self.nsp!)")
@@ -212,15 +279,21 @@ class SocketIOClient: NSObject, SRWebSocketDelegate {
     }
     
     // Adds handler for single arg message
-    func on(name:String, callback:NormalCallback) {
-        let handler = SocketEventHandler(event: name, callback: callback)
+    func on(name:String, callback:NormalCallback) -> SocketAckHandler {
+        let ackHandler = SocketAckHandler(event: name)
+        let handler = SocketEventHandler(event: name, callback: callback, ack: ackHandler)
         self.handlers.append(handler)
+        
+        return ackHandler
     }
     
     // Adds handler for multiple arg message
-    func onMultipleItems(name:String, callback:MultipleCallback) {
-        let handler = SocketEventHandler(event: name, callback: callback)
+    func onMultipleItems(name:String, callback:MultipleCallback) -> SocketAckHandler {
+        let ackHandler = SocketAckHandler(event: name)
+        let handler = SocketEventHandler(event: name, callback: callback, ack: ackHandler)
         self.handlers.append(handler)
+        
+        return ackHandler
     }
     
     // Opens the connection to the socket
@@ -296,6 +369,59 @@ class SocketIOClient: NSObject, SRWebSocketDelegate {
         return parsed
     }
     
+    private class func parseEmitArgs(args:[AnyObject]) -> ([AnyObject], Bool, [NSData]) {
+        var items = [AnyObject](count: args.count, repeatedValue: 1)
+        var numberOfPlaceholders = -1
+        var hasBinary = false
+        var emitDatas = [NSData]()
+        
+        for i in 0..<args.count {
+            if let dict = args[i] as? NSDictionary {
+                // Check for binary data
+                let (newDict, hadBinary, binaryDatas) = SocketIOClient.parseNSDictionary(dict,
+                    placeholders: numberOfPlaceholders)
+                if hadBinary {
+                    numberOfPlaceholders = binaryDatas.count
+                    
+                    emitDatas.extend(binaryDatas)
+                    hasBinary = true
+                    items[i] = newDict
+                } else {
+                    items[i] = dict
+                }
+            } else if let arr = args[i] as? NSArray {
+                // arg is array, check for binary
+                let (replace, hadData, newDatas) = SocketIOClient.parseArray(arr,
+                    placeholders: numberOfPlaceholders)
+                
+                if hadData {
+                    hasBinary = true
+                    numberOfPlaceholders += emitDatas.count
+                    
+                    for data in newDatas {
+                        emitDatas.append(data)
+                    }
+                    
+                    items[i] = replace
+                } else {
+                    items[i] = arr
+                }
+            } else if let binaryData = args[i] as? NSData {
+                // args is just binary
+                hasBinary = true
+                let sendData = SocketIOClient.createBinaryDataForSend(binaryData)
+                
+                numberOfPlaceholders++
+                items[i] = ["_placeholder": true, "num": numberOfPlaceholders]
+                emitDatas.append(sendData)
+            } else {
+                items[i] = args[i]
+            }
+        }
+        
+        return (items, hasBinary, emitDatas)
+    }
+    
     // Parses a NSDictionary, looking for NSData objects
     private class func parseNSDictionary(dict:NSDictionary, var placeholders:Int) -> (NSDictionary, Bool, [NSData]) {
         var returnDict = NSMutableDictionary()
@@ -354,7 +480,7 @@ class SocketIOClient: NSObject, SRWebSocketDelegate {
             // Check for successful namepsace connect
             if self.nsp != nil {
                 if stringMessage == "40/\(self.nsp!)" {
-                    self.handleEvent(event: "connect", data: nil)
+                    self.handleEvent("connect", data: nil)
                     return
                 }
             }
@@ -384,17 +510,25 @@ class SocketIOClient: NSObject, SRWebSocketDelegate {
             /**
             Begin check for message
             **/
-            let messageGroups = mutMessage["(\\d*)\\/?(\\w*)?,?(\\[.*\\])?"].groups()
+            let messageGroups = mutMessage["(\\d*)\\/?(\\w*)?,?(\\d*)?(\\[.*\\])?"].groups()
             
-            if messageGroups[1] == "42" {
+            if messageGroups[1].hasPrefix("42") {
+                var mesNum = messageGroups[1]
+                var ackNum:String
                 var namespace:String?
                 var messagePart:String!
                 
-                if messageGroups.count == 4 {
-                    namespace = messageGroups[2]
-                    messagePart = messageGroups[3]
+                if messageGroups[3] != "" {
+                    ackNum = messageGroups[3]
+                } else {
+                    let range = Range<String.Index>(start: mesNum.startIndex, end: advance(mesNum.startIndex, 2))
+                    mesNum.replaceRange(range, with: "")
+                    ackNum = mesNum
                 }
                 
+                namespace = messageGroups[2]
+                messagePart = messageGroups[4]
+                
                 if namespace == "" && self.nsp != nil {
                     return
                 }
@@ -413,7 +547,13 @@ class SocketIOClient: NSObject, SRWebSocketDelegate {
                     // It would be nice if socket.io only allowed one thing
                     // per message, but alas, it doesn't.
                     if let parsed:AnyObject = SocketIOClient.parseData(data) {
-                        self.handleEvent(event: event, data: parsed)
+                        if ackNum == "" {
+                            self.handleEvent(event, data: parsed)
+                        } else {
+                            self.currentAck = ackNum.toInt()!
+                            self.handleEvent(event, data: parsed, isInternalMessage: false,
+                                wantsAck: ackNum.toInt(), withAckType: 3)
+                        }
                         return
                     } else if let strData = data {
                         // There are multiple items in the message
@@ -421,7 +561,13 @@ class SocketIOClient: NSObject, SRWebSocketDelegate {
                         // parseData to try and get an array.
                         let asArray = "[\(strData)]"
                         if let parsed:AnyObject = SocketIOClient.parseData(asArray) {
-                            self.handleEvent(event: event, data: parsed, multipleItems: true)
+                            if ackNum == "" {
+                                self.handleEvent(event, data: parsed)
+                            } else {
+                                self.currentAck = ackNum.toInt()!
+                                self.handleEvent(event, data: parsed, isInternalMessage: false,
+                                    wantsAck: ackNum.toInt(), withAckType: 3)
+                            }
                             return
                         }
                     }
@@ -431,9 +577,34 @@ class SocketIOClient: NSObject, SRWebSocketDelegate {
                 let noItemMessage = RegexMutable(messagePart)["\\[\"(.*?)\"]$"].groups()
                 if noItemMessage != nil && noItemMessage.count == 2 {
                     let event = noItemMessage[1]
-                    self.handleEvent(event: event, data: nil, multipleItems: false)
+                    if ackNum == "" {
+                        self.handleEvent(event, data: nil)
+                    } else {
+                        self.currentAck = ackNum.toInt()!
+                        self.handleEvent(event, data: nil, isInternalMessage: false,
+                            wantsAck: ackNum.toInt(), withAckType: 3)
+                    }
                     return
                 }
+            } else if messageGroups[1].hasPrefix("43") {
+                let arr = Array(messageGroups[1])
+                var ackNum:String
+                let nsp = messageGroups[2]
+                
+                if nsp == "" && self.nsp != nil {
+                    return
+                }
+                
+                if nsp == "" {
+                    ackNum = String(arr[2...arr.count-1])
+                } else {
+                    ackNum = messageGroups[3]
+                }
+                
+                let ackData:AnyObject? = SocketIOClient.parseData(messageGroups[4])
+                self.handleAck(ackNum.toInt()!, data: ackData)
+                
+                return
             }
             /**
             End Check for message
@@ -463,23 +634,34 @@ class SocketIOClient: NSObject, SRWebSocketDelegate {
             /**
             Begin check for binary placeholders
             **/
-            let binaryGroup = mutMessage["(\\d*)-\\/?(\\w*)?,?\\[(\".*?\"),(.*)\\]$"].groups()
+            let binaryGroup = mutMessage["^(\\d*)-\\/?(\\w*)?,?(\\d*)?\\[(\".*?\")?,?(.*)?\\]$"].groups()
             
-            if binaryGroup != nil {
+            if binaryGroup == nil {
+                return
+            }
+            
+            if binaryGroup[1].hasPrefix("45") {
                 // println(binaryGroup)
-                var event:String!
-                var mutMessageObject:NSMutableString!
+                var ackNum:String
+                var event:String
+                var mutMessageObject:NSMutableString
                 var namespace:String?
+                var numberOfPlaceholders:String
                 let messageType = RegexMutable(binaryGroup[1])
-                let numberOfPlaceholders = messageType["45"] ~= ""
                 
-                // Check if message came from a namespace
-                if binaryGroup.count == 5 {
-                    namespace = binaryGroup[2]
-                    event = RegexMutable(binaryGroup[3])["\""] ~= ""
-                    mutMessageObject = RegexMutable(binaryGroup[4])
+                namespace = binaryGroup[2]
+                if binaryGroup[3] != "" {
+                    ackNum = binaryGroup[3] as String
+                } else if self.nsp == nil && binaryGroup[2] != "" {
+                    ackNum = binaryGroup[2]
+                } else {
+                    ackNum = ""
                 }
                 
+                numberOfPlaceholders = (messageType["45"] ~= "") as String
+                event = (RegexMutable(binaryGroup[4])["\""] ~= "") as String
+                mutMessageObject = RegexMutable(binaryGroup[5])
+                
                 if namespace == "" && self.nsp != nil {
                     self.lastSocketMessage = nil
                     return
@@ -488,9 +670,40 @@ class SocketIOClient: NSObject, SRWebSocketDelegate {
                 let placeholdersRemoved = mutMessageObject["(\\{\"_placeholder\":true,\"num\":(\\d*)\\})"]
                     ~= "\"~~$2\""
                 
-                let mes = SocketEvent(event: event, args: placeholdersRemoved,
-                    placeholders: numberOfPlaceholders.integerValue)
+                var mes:SocketEvent
+                if ackNum == "" {
+                    mes = SocketEvent(event: event, args: placeholdersRemoved,
+                        placeholders: numberOfPlaceholders.toInt()!)
+                } else {
+                    self.currentAck = ackNum.toInt()!
+                    mes = SocketEvent(event: event, args: placeholdersRemoved,
+                        placeholders: numberOfPlaceholders.toInt()!, ackNum: ackNum.toInt())
+                }
+                
                 self.lastSocketMessage = mes
+            } else if binaryGroup[1].hasPrefix("46") {
+                let messageType = RegexMutable(binaryGroup[1])
+                let numberOfPlaceholders = (messageType["46"] ~= "") as String
+                var ackNum:String
+                var nsp:String
+                
+                if binaryGroup[3] == "" {
+                    ackNum = binaryGroup[2]
+                    nsp = ""
+                } else {
+                    ackNum = binaryGroup[3]
+                    nsp = binaryGroup[2]
+                }
+                
+                if nsp == "" && self.nsp != nil {
+                    return
+                }
+                var mutMessageObject = RegexMutable(binaryGroup[5])
+                let placeholdersRemoved = mutMessageObject["(\\{\"_placeholder\":true,\"num\":(\\d*)\\})"]
+                    ~= "\"~~$2\""
+                
+                self.lastSocketMessage = SocketEvent(event: "", args: placeholdersRemoved,
+                    placeholders: numberOfPlaceholders.toInt()!, ackNum: ackNum.toInt(), justAck: true)
             }
             /**
             End check for binary placeholders
@@ -508,11 +721,32 @@ class SocketIOClient: NSObject, SRWebSocketDelegate {
             
             if let args:AnyObject = parsedArgs {
                 let filledInArgs:AnyObject = self.lastSocketMessage!.fillInPlaceholders(args)
-                self.handleEvent(event: event, data: filledInArgs)
+                
+                if self.lastSocketMessage!.justAck! {
+                    self.handleAck(self.lastSocketMessage!.ack!, data: filledInArgs)
+                    return
+                }
+                
+                if self.lastSocketMessage!.ack != nil {
+                    self.handleEvent(event, data: filledInArgs, isInternalMessage: false,
+                        wantsAck: self.lastSocketMessage!.ack!, withAckType: 6)
+                } else {
+                    self.handleEvent(event, data: filledInArgs)
+                }
             } else {
                 let filledInArgs:AnyObject = self.lastSocketMessage!.fillInPlaceholders()
-                self.handleEvent(event: event, data: filledInArgs, multipleItems: true)
-                return
+                
+                if self.lastSocketMessage!.justAck! {
+                    self.handleAck(self.lastSocketMessage!.ack!, data: filledInArgs)
+                    return
+                }
+                
+                if self.lastSocketMessage!.ack != nil {
+                    self.handleEvent(event, data: filledInArgs, isInternalMessage: false,
+                        wantsAck: self.lastSocketMessage!.ack!, withAckType: 6)
+                } else {
+                    self.handleEvent(event, data: filledInArgs)
+                }
             }
         }
     }
@@ -525,8 +759,10 @@ class SocketIOClient: NSObject, SRWebSocketDelegate {
     
     // Starts the ping timer
     private func startPingTimer(#interval:Int) {
-        self.pingTimer = NSTimer.scheduledTimerWithTimeInterval(NSTimeInterval(interval), target: self,
-            selector: Selector("sendPing"), userInfo: nil, repeats: true)
+        dispatch_async(dispatch_get_main_queue()) {
+            self.pingTimer = NSTimer.scheduledTimerWithTimeInterval(NSTimeInterval(interval), target: self,
+                selector: Selector("sendPing"), userInfo: nil, repeats: true)
+        }
     }
     
     // We lost connection and should attempt to reestablish
@@ -535,7 +771,7 @@ class SocketIOClient: NSObject, SRWebSocketDelegate {
             self.connecting = false
             self.reconnects = false
             self.reconnecting = false
-            self.handleEvent(event: "disconnect", data: "Failed to reconnect")
+            self.handleEvent("disconnect", data: "Failed to reconnect", isInternalMessage: true)
             return
         } else if self.connected {
             self.connecting = false
@@ -544,7 +780,7 @@ class SocketIOClient: NSObject, SRWebSocketDelegate {
         }
         
         // println("Trying to reconnect #\(reconnectAttempts - triesLeft)")
-        self.handleEvent(event: "reconnectAttempt", data: triesLeft)
+        self.handleEvent("reconnectAttempt", data: triesLeft, isInternalMessage: true)
         
         let waitTime = UInt64(self.reconnectWait) * NSEC_PER_SEC
         let time = dispatch_time(DISPATCH_TIME_NOW, Int64(waitTime))
@@ -567,7 +803,13 @@ class SocketIOClient: NSObject, SRWebSocketDelegate {
     
     // Called when a message is recieved
     func webSocket(webSocket:SRWebSocket!, didReceiveMessage message:AnyObject?) {
-        self.parseSocketMessage(message)
+        dispatch_async(self.handleQueue) {[weak self] in
+            if self == nil {
+                return
+            }
+            
+            self?.parseSocketMessage(message)
+        }
     }
     
     // Called when the socket is opened
@@ -583,7 +825,9 @@ class SocketIOClient: NSObject, SRWebSocketDelegate {
             return
         }
         
-        self.handleEvent(event: "connect", data: nil)
+        // Don't handle as internal because something crazy could happen where
+        // we disconnect before it's handled
+        self.handleEvent("connect", data: nil)
     }
     
     // Called when the socket is closed
@@ -592,9 +836,9 @@ class SocketIOClient: NSObject, SRWebSocketDelegate {
         self.connected = false
         self.connecting = false
         if self.closed || !self.reconnects {
-            self.handleEvent(event: "disconnect", data: reason)
+            self.handleEvent("disconnect", data: reason, isInternalMessage: true)
         } else {
-            self.handleEvent(event: "reconnect", data: reason)
+            self.handleEvent("reconnect", data: reason, isInternalMessage: true)
             self.tryReconnect(triesLeft: self.reconnectAttempts)
             
         }
@@ -605,11 +849,11 @@ class SocketIOClient: NSObject, SRWebSocketDelegate {
         self.pingTimer?.invalidate()
         self.connected = false
         self.connecting = false
-        self.handleEvent(event: "error", data: error.localizedDescription)
+        self.handleEvent("error", data: error.localizedDescription, isInternalMessage: true)
         if self.closed || !self.reconnects {
-            self.handleEvent(event: "disconnect", data: error.localizedDescription)
+            self.handleEvent("disconnect", data: error.localizedDescription, isInternalMessage: true)
         } else if !self.reconnecting {
-            self.handleEvent(event: "reconnect", data: error.localizedDescription)
+            self.handleEvent("reconnect", data: error.localizedDescription, isInternalMessage: true)
             self.tryReconnect(triesLeft: self.reconnectAttempts)
         }
     }
diff --git a/SwiftIO/SwiftRegex.swift b/SwiftIO/SwiftRegex.swift
index 96c03cf..16527ab 100644
--- a/SwiftIO/SwiftRegex.swift
+++ b/SwiftIO/SwiftRegex.swift
@@ -13,7 +13,7 @@
 
 import Foundation
 
-var swiftRegexCache = Dictionary<String,NSRegularExpression>()
+var swiftRegexCache = [String: NSRegularExpression]()
 
 public class SwiftRegex: NSObject, BooleanType {
     
@@ -60,15 +60,15 @@ public class SwiftRegex: NSObject, BooleanType {
     }
     
     public func range(options: NSMatchingOptions = nil) -> NSRange {
-        return regex.rangeOfFirstMatchInString(target, options: nil, range: targetRange)
+        return regex.rangeOfFirstMatchInString(target as String, options: nil, range: targetRange)
     }
     
     public func match(options: NSMatchingOptions = nil) -> String! {
-        return substring(range(options: options))
+        return substring(range(options: options)) as String
     }
     
     public func groups(options: NSMatchingOptions = nil) -> [String]! {
-        return groupsForMatch( regex.firstMatchInString(target, options: options, range: targetRange) )
+        return groupsForMatch( regex.firstMatchInString(target as String, options: options, range: targetRange) )
     }
     
     func groupsForMatch(match: NSTextCheckingResult!) -> [String]! {
@@ -93,9 +93,9 @@ public class SwiftRegex: NSObject, BooleanType {
         }
         set(newValue) {
             if let mutableTarget = target as? NSMutableString {
-                for match in matchResults().reverse() {
+                for match in matchResults()!.reverse() {
                     let replacement = regex.replacementStringForResult( match,
-                        inString: target, offset: 0, template: newValue )
+                        inString: target as String, offset: 0, template: newValue )
                     mutableTarget.replaceCharactersInRange(match.rangeAtIndex(groupno), withString: replacement)
                 }
             } else {
@@ -104,26 +104,33 @@ public class SwiftRegex: NSObject, BooleanType {
         }
     }
     
-    func matchResults(options: NSMatchingOptions = nil) -> [NSTextCheckingResult] {
-        return regex.matchesInString(target, options: options, range: targetRange) as [NSTextCheckingResult]
+    func matchResults(options: NSMatchingOptions = nil) -> [NSTextCheckingResult]? {
+        let matches = regex.matchesInString(target as String, options: options, range: targetRange)
+            as? [NSTextCheckingResult]
+        
+        if matches != nil {
+            return matches!
+        } else {
+            return nil
+        }
     }
     
     public func ranges(options: NSMatchingOptions = nil) -> [NSRange] {
-        return matchResults(options: options).map { $0.range }
+        return matchResults(options: options)!.map { $0.range }
     }
     
     public func matches(options: NSMatchingOptions = nil) -> [String] {
-        return matchResults(options: options).map { self.substring($0.range) }
+        return matchResults(options: options)!.map( { self.substring($0.range) as String } )
     }
     
     public func allGroups(options: NSMatchingOptions = nil) -> [[String]] {
-        return matchResults(options: options).map { self.groupsForMatch($0) }
+        return matchResults(options: options)!.map { self.groupsForMatch($0) }
     }
     
     public func dictionary(options: NSMatchingOptions = nil) -> Dictionary<String,String> {
         var out = Dictionary<String,String>()
-        for match in matchResults(options: options) {
-            out[substring(match.rangeAtIndex(1))] =
+        for match in matchResults(options: options)! {
+            out[substring(match.rangeAtIndex(1)) as String] =
                 substring(match.rangeAtIndex(2))
         }
         return out
@@ -134,19 +141,19 @@ public class SwiftRegex: NSObject, BooleanType {
             let out = NSMutableString()
             var pos = 0
             
-            regex.enumerateMatchesInString(target, options: options, range: targetRange ) {
+            regex.enumerateMatchesInString(target as String, options: options, range: targetRange ) {
                 (match: NSTextCheckingResult!, flags: NSMatchingFlags, stop: UnsafeMutablePointer<ObjCBool>) in
                 
                 let matchRange = match.range
-                out.appendString( self.substring( NSRange(location:pos, length:matchRange.location-pos) ) )
+                out.appendString( self.substring( NSRange(location:pos, length:matchRange.location-pos) ) as String )
                 out.appendString( substitution(match, stop) )
                 pos = matchRange.location + matchRange.length
             }
             
-            out.appendString( substring( NSRange(location:pos, length:targetRange.length-pos) ) )
+            out.appendString( substring( NSRange(location:pos, length:targetRange.length-pos) ) as String )
             
             if let mutableTarget = target as? NSMutableString {
-                mutableTarget.setString(out)
+                mutableTarget.setString(out as String)
                 return mutableTarget
             } else {
                 SwiftRegex.failure("Modify on non-mutable")
@@ -208,43 +215,41 @@ extension String {
 }
 
 public func RegexMutable(string: NSString) -> NSMutableString {
-    return NSMutableString(string:string)
+    return NSMutableString(string:string as String)
 }
 
 public func ~= (left: SwiftRegex, right: String) -> NSMutableString {
-    return left.substituteMatches {
-        (match: NSTextCheckingResult, stop: UnsafeMutablePointer<ObjCBool>) in
+    return left.substituteMatches({match, stop in
         return left.regex.replacementStringForResult( match,
-            inString: left.target, offset: 0, template: right )
-    }
+            inString: left.target as String, offset: 0, template: right )
+    }, options: nil)
 }
 
 public func ~= (left: SwiftRegex, right: [String]) -> NSMutableString {
     var matchNumber = 0
-    return left.substituteMatches {
-        (match: NSTextCheckingResult, stop: UnsafeMutablePointer<ObjCBool>) in
+    return left.substituteMatches({match, stop -> String in
         
         if ++matchNumber == right.count {
             stop.memory = true
         }
         
         return left.regex.replacementStringForResult( match,
-            inString: left.target, offset: 0, template: right[matchNumber-1] )
-    }
+            inString: left.target as String, offset: 0, template: right[matchNumber-1] )
+    }, options: nil)
 }
 
 public func ~= (left: SwiftRegex, right: (String) -> String) -> NSMutableString {
-    return left.substituteMatches {
-        (match: NSTextCheckingResult, stop: UnsafeMutablePointer<ObjCBool>) in
-        return right(left.substring(match.range))
-    }
+    // return right(left.substring(match.range))
+    return left.substituteMatches(
+        {match, stop -> String in
+            right(left.substring(match.range) as String)
+        }, options: nil)
 }
 
 public func ~= (left: SwiftRegex, right: ([String]) -> String) -> NSMutableString {
-    return left.substituteMatches {
-        (match: NSTextCheckingResult, stop: UnsafeMutablePointer<ObjCBool>) in
+    return left.substituteMatches({match, stop -> String in
         return right(left.groupsForMatch(match))
-    }
+    }, options: nil)
 }
 
 // my take on custom threading operators from