Pre-release protocol
This page documents the changes from the last stable Minecraft release (currently 1.3.2) to the current pre-release (or weekly release).
Contents
New packets
-None-
Changed packets
Time Update (0x04)
Server to Client
Time is based on ticks, where 20 ticks happen every second. There are 24000 ticks in a day, making Minecraft days exactly 20 minutes long.
The time of day is based on the timestamp modulo 24000. 0 is sunrise, 6000 is noon, 12000 is sunset, and 18000 is midnight.
The default SMP server increments both by 20 every second.
The 'Time' is the Age of the world. It is not changing on server commands and will increased by 20 every second.
Packet ID | Field Name | Field Type | Example | Notes |
---|---|---|---|---|
0x04 | Time | long | 45464654 | The 'Age of the world', in ticks |
Day Time | long | 21321 | The world (or region) time, in ticks | |
Total Size: | 17 Bytes |
Spawn Named Entity (0x14)
See the change in metadata below. (Under Protocol History, 2012-08-24)
Spawn Dropped Item (0x15)
TODO
It includes a new byte array after the "Damage" field, and before the "X" field if certain conditions are met. If the array does not exist, then the length of the array is "-1".
Spawn Mob (0x18)
See the change in metadata below. (Under Protocol History, 2012-08-24)
Entity Metadata (0x28)
See the change in metadata below. (Under Protocol History, 2012-08-24)
Click Window (0x66)
Client to Server
This packet is sent by the player when it clicks on a slot in a window.
Packet ID | Field Name | Field Type | Example | Notes |
0x66 | Window id | byte | 0
|
The id of the window which was clicked. 0 for player inventory. |
Slot | short | 36
|
The clicked slot. See below. | |
Right-click | byte | 1
|
||
Action number | short | 12
|
A unique number for the action, used for transaction handling (See the Transaction packet). | |
Shift | boolean | 0
|
This is true if the user was holding keyboard shift when they clicked. | |
Clicked item | slot | |||
Total Size: | 9 bytes + slot data |
Locale and View Distance (0xCC)
Client to server
Sent when the player connects, or when settings are changed.
Packet ID | Field Name | Field Type | Example | Notes |
0xCC | Locale | string | en_GB | |
View distance | byte | 0 | 0-3 for 'far', 'normal', 'short', 'tiny'. | |
Chat flags | byte | 8 | Chat settings. See notes below. | |
Difficulty | byte | 0 | Client-side difficulty from options.txt | |
Show Cape | boolean | true | Client-side "show cape" option | |
Total Size: | 9 bytes + length of string |
Changed data types
Entity Metadata Format
Note that entity metadata is a totally distinct concept from block metadata.
The entity metadata format is quirky dictionary format, where the key and the value's type are packed in a single byte.
To parse, repeat the following procedure:
- Read an unsigned byte
- If this byte == 127, stop reading
- Decompose the byte.
The bottom 5 bits (0x1F) serve as an identifier (key) for the data to follow.
The top 3 bits (0xE0) serve as a type. - Read and unpack based on the type (below)
Type | Meaning |
---|---|
0 | byte |
1 | short |
2 | int |
3 | float |
4 | string16 |
5 | short, byte, short (slot type) - If first short is empty, no further data is sent. |
6 | int, int, int (x, y, z) |
In Python-like code:
#socket is positioned at the beginning of the metadata array. Also note that the method unpack() doesn't exist in socket
metadata = {}
x = socket.unpack('byte')
while x != 127:
index = x & 0x1F # Lower 5 bits
ty = x >> 5 # Upper 3 bits
if ty == 0: val = socket.unpack('byte')
if ty == 1: val = socket.unpack('short')
if ty == 2: val = socket.unpack('int')
if ty == 3: val = socket.unpack('float')
if ty == 4: val = socket.unpack('string16')
if ty == 5:
val = {}
val["id"] = socket.unpack('short')
if val["id"] != -1:
val["count"] = socket.unpack('byte')
val["damage"] = socket.unpack('short')
if ty == 6:
val = []
for i in range(3):
val.append(socket.unpack('int'))
metadata[index] = (ty, val)
x = socket.unpack('byte')
return metadata
Removed packets
-None-
Protocol History
2012-10-11
- 12w41a
- Protocol version is now 46
- 0xcc Changed to include boolean 'show cape' field.
2012-10-04
- 12w40a
- Protocol version is now 45
- Packet 0x66 changed
2012-09-06
- 12w36a
- Protocol version is now 42
2012-08-24
- 12w34b
- Protocol version is now 41
- Changed Entity Metadata Format
2012-08-09
- 12w32a
- Protocol version is now 40
- Changed Time Update packet