diff --git a/Docs/Dev/README.md b/Docs/Dev/README.md
index e69de29..415dab6 100644
--- a/Docs/Dev/README.md
+++ b/Docs/Dev/README.md
@@ -0,0 +1,68 @@
+# Developer guids for Socket Data Handler
+
+My recommendation is read this after you go through the [User guids for Socket Data Handler](../User/README.md).
+
+- [Developer guids for Socket Data Handler](#developer-guids-for-socket-data-handler)
+    - [Data Types](#data-types)
+    - [The `DataHandler`](#the-datahandler)
+    - [The `header`](#the-header)
+    - [The `timestamp`](#the-timestamp)
+    - [Appending the content](#appending-the-content)
+
+## Data types
+
+`Socket Data Handler` is using 3 data types for communications.
+
+- NONE (just a `String` request of the `header`) [type `0`]
+- FILE (`java.io.File`) [type `1`]
+- OBJECT (any `serializable` object) [type `2`]
+
+## The `DataHandler`
+
+You must need a instance of `DataHandler` for send and receive data using this library. It's only bound to this library,
+and it's **not a must** for the protocol. For more info. please look at the `Java-Doc`.
+
+## The `header`
+
+`Socket Data Handler` using a unique protocol for communications. If you are going to contribute or make your own
+library for this, you should know how it works.
+
+The main part of this protocol is the `header`. In the library,
+the [`DataProcessor`](../../src/main/java/io/github/naveenb2004/SocketDataHandler/DataProcessor.java) is the core for
+making that `header` (the `serialize` method). All `header`s are `UTF-8 String`s.
+
+> Sample header
+
+```json
+{6,0,0}
+```
+
+`header` is only containing 3 elements enclosed by `{}` and seperated by `,`.
+
+- The first element is the `bytes length of the request (UTF-8 String)`.
+- The second element is the `data type`
+- The third element is the `bytes length of the body`
+
+Let's assume that we want to send a `File` of `2KB` with the `request`, `/samleFile`. Then the `header` is like this.
+
+```json
+{10,1,2048}
+```
+
+Now the library knows the bounds of the **variables**!
+
+## The `timestamp`
+
+All invocation of the `send` method is making a header (please look at [The header](#the-header) section for more about
+the `header`s). The `timestamp` is part of the request content, but not showed-up in `header`. Timestamp is using
+the [`Java` system milliseconds](https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/System.html#currentTimeMillis()).
+If you're going to use `ping` requests, please take a look at that. But why it's not in `header`? It's because
+the `timestamp` always has **13 bytes**. It can be hardcoded!
+
+## Appending the content
+
+- Append the `header`
+- Append the `request`
+- Append the `timestamp`
+- If it's a `File`, append the `file extension` and `$` (eg: myImage.png -> `png$`)
+- If there's a body, append it
\ No newline at end of file
diff --git a/Docs/User/README.md b/Docs/User/README.md
index f90562e..f80dcf8 100644
--- a/Docs/User/README.md
+++ b/Docs/User/README.md
@@ -8,6 +8,7 @@
     - [Receiving pre-updates](#receiving-pre-updates)
     - [Send data](#send-data)
     - [Close socket](#close-socket)
+    - [Further Reading](#further-reading)
 
 ## Import into the project
 
@@ -134,6 +135,11 @@ try {
 }
 ```
 
+## Connection between `onUpdateReceived` and `preUpdateSeen`
+
+When an update received to the `receiver`/`sender`, it automatically give a `UUID (Universally Unique Identifier)` for
+that request/response. If your request/response is eligible for `pre-update` it will automatically share that `UUID`.
+
 ## Close socket
 
 You can either direct close the socket or use `close` method of your receiver class that `extends` with
@@ -145,4 +151,8 @@ try {
 } catch (IOException e) {
     throw new RuntimeException(e);
 }
-```
\ No newline at end of file
+```
+
+## Further reading
+
+Please take a look at the `Java-Doc` to get a clear idea about methods and interfaces. 
\ No newline at end of file
diff --git a/src/main/java/io/github/naveenb2004/SocketDataHandler/SocketDataHandler.java b/src/main/java/io/github/naveenb2004/SocketDataHandler/SocketDataHandler.java
index 04433b4..669db91 100644
--- a/src/main/java/io/github/naveenb2004/SocketDataHandler/SocketDataHandler.java
+++ b/src/main/java/io/github/naveenb2004/SocketDataHandler/SocketDataHandler.java
@@ -53,7 +53,7 @@ public static void setDefaultBufferSize(int defaultBufferSize) {
     @Synchronized
     public void send(@NonNull DataHandler dataHandler) throws IOException {
         OutputStream os = SOCKET.getOutputStream();
-        byte[] buffer = new byte[Math.toIntExact(defaultBufferSize)];
+        byte[] buffer = new byte[defaultBufferSize];
         PreDataHandler preDataHandler = null;
         if (dataHandler.getDataType() != DataHandler.DataType.NONE) {
             preDataHandler = new PreDataHandler(PRE_UPDATE_HANDLER, dataHandler.getUUID(),