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RakNet is a networking library used by Minecraft Bedrock Edition. You might want to also look at the documentation for the Bedrock Protocol.
This is based on the old Pocket Edition Protocol Documentation and may be incomplete or outdated.
The source code for the RakNet Library can be found here.
RakNet uses UDP as its networking protocol. The key differences from TCP are that not all packets are guaranteed to reach the destination at all or in order (it isn't reliable) and it uses messages with a specified length instead of streams of data. RakNet compensates for the out-of-order delivery and makes it reliable.
NOTE:
You may want to use an existing library if one exists for your language of choice.
Here is an incomplete list. Not all of these are maintained or complete. If these are outdated you may need to change the protocol version to 10 before it can work. The protocol doesn't seem to have had any significant changes since the official implementation was discontinued in 2014, so as long as you bump the protocol version older libraries are likely to still work.
| Name
|
Description
|
Language
|
License
|
Active development
|
| NukkitX Network
|
Network components used within NukkitX, but with great support for general use as well
|
Java
|
Apache License
|
Yes
|
| rak-net
|
rak-net is the first updated and fully working RakNet implementation written in Python to run a Minecraft Bedrock Edition server. This library was mainly created for Podrum, although it can be used in other projects too and can be installed via pip.
|
Python
|
MIT
|
Yes
|
| JRakNet
|
JRakNet is a networking library for Java which implements the UDP based protocol RakNet
|
Java
|
MIT
|
Yes
|
| netty-raknet
|
High performance implementation of RakNet for netty, following strict netty patterns.
|
Java
|
MIT
|
Yes
|
| JSRakNet
|
JSRakNet is the first up to date and fully working raknet implementation written in Javascript to run a Minecraft PE server, designed mainly for JSPrismarine, but the implementation offers a general use
|
Javascript
|
MIT
|
Yes
|
| JRakLibPlus
|
A library for easy creation of RakNet servers, based on RakLib and JRakLib.
|
Java
|
LGPL
|
No
|
| RakLib
|
RakNet server implementation written in PHP. This library is very lightweight on actual implementation - it provides the bare minimum to get a Minecraft Pocket Edition server functional. It only currently provides server functionality, and does not support most RakNet features.
|
PHP
|
GPL
|
Yes
|
| raknet
|
UDP network library that follows the RakNet protocol for Node.js
|
Javascript
|
MIT
|
No
|
| PyRakLib
|
PyRakLib is a networking library that follows the RakNet protocol for MCPE. It is ported from the PHP library RakLib.
|
Python
|
GPL
|
No
|
| Raknet (official)
|
The official implementation. Outdated and mostly for reference purposes. May not work with the latest Bedrock.
|
C++
|
BSD
|
No
|
Data types
|
|
Size (Bytes)
|
Range
|
Notes
|
| byte
|
1
|
0 to 255
|
|
| Long
|
8
|
-2^63 to 2^63-1
|
Signed 64-bit Integer
|
| Magic
|
16
|
00ffff00fefefefefdfdfdfd12345678
|
Always those hex bytes, corresponding to RakNet's default OFFLINE_MESSAGE_DATA_ID
|
| short
|
2
|
-32768 to 32767
|
|
| unsigned short
|
2
|
0 to 65535
|
|
| string
|
unsigned short + string
|
N/A
|
Prefixed by a short containing the length of the string in characters. It appears that only the following ASCII characters can be displayed: !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~
|
| boolean
|
1
|
0 to 1
|
True is encoded as 0x01, false as 0x00.
|
| address
|
7
|
|
1 byte for the IP version (4 or 6), followed by (for IPv4) 4 bytes for the IP and an unsigned short for the port number
|
| uint24le
|
3
|
|
3-byte little-endian unsigned integer
|
Handshake sequence
- C→S: Open Connection Request 1
- S→C: Open Connection Reply 1
- C→S: Open Connection Request 2
- S→C: Open Connection Reply 2
From here on, the RakNet connection is established and all RakNet messages are contained in a Frame Set Packet.
- C→S: Connection Request
- S→C: Connection Request Accepted
- C→S: New Incoming Connection
Next packets should be Game Packet
Packets
Unconnected Ping
| Packet ID
|
Field Name
|
Field Type
|
Notes
|
| 0x01, 0x02
|
Time
|
Long
|
|
| MAGIC
|
magic
|
|
| Client GUID
|
Long
|
|
0x02 is only replied to if there are open connections to the server. Note: as of 0.15.6 it seems that the game refreshes it's LAN world list every 4-5 seconds, however it seems the game will still ping in 1 second intervals.
This packet should be responded to with unconnected Pong.
Unconnected Pong
| Packet ID
|
Field Name
|
Field Type
|
Notes
|
| 0x1c
|
Time
|
Long
|
|
| Server GUID
|
Long
|
|
| MAGIC
|
magic
|
|
| Server ID string
|
string
|
Used for the MOTD. See below for details.
|
Server ID string format
For Minecraft Bedrock this is separated by semicolons and uses the following format:
Edition (MCPE or MCEE for Education Edition);MOTD line 1;Protocol Version;Version Name;Player Count;Max Player Count;Server Unique ID;MOTD line 2;Game mode;Game mode (numeric);Port (IPv4);Port (IPv6);
Example:
MCPE;Dedicated Server;390;1.14.60;0;10;13253860892328930865;Bedrock level;Survival;1;19132;19133;
Result:
The Game mode and Game mode (numeric) values seem to not be used by the client.
Connected Ping
| Packet ID
|
Field Name
|
Field Type
|
Notes
|
| 0x00
|
Time
|
Long
|
|
Connected Pong
| Packet ID
|
Field Name
|
Field Type
|
Notes
|
| 0x03
|
Ping Time
|
Long
|
|
| Pong Time
|
Long
|
|
Open Connection Request 1
| Packet ID
|
Field Name
|
Field Type
|
Notes
|
| 0x05
|
Magic
|
MAGIC
|
|
| Protocol version
|
byte
|
Currently 10
|
| MTU
|
Zero padding
|
The MTU sent in the response appears to be somewhere around the size of this padding + 46 (28 udp overhead, 1 packet id, 16 magic, 1 protocol version). This padding seems to be used to discover the maximum packet size the network can handle.
|
The client sends these to the target server with ever decreasing MTU until the server responds. This is used to discover the MTU size for the connection. According to the official docs, "The MTU size is the maximum size of a packet RakNet will generate", and "if you set the MTU size larger than your or any router along the network path takes, then the network will split the packet at best, or drop it at worst", so this process of sending decreasingly padded packets (compensating for the size of the packet itself and UDP overhead, which together make 48 bytes) seem to be used to discover the maximum packet size the network can handle. See the official documentation page for more info about the MTU size. If the RakNet protocol does not match your own, respond with the Incompatible protocol packet.
You should always respond to the first of these packets that you receive with Open Connection Reply 1, containing an MTU size of the amount of padding you received in bytes plus 46.
Open Connection Reply 1
| Packet ID
|
Field Name
|
Field Type
|
Notes
|
| 0x06
|
Magic
|
MAGIC
|
|
| Server GUID
|
Long
|
|
| Use security
|
boolean
|
Make sure this is false, it is vital for the login sequence to continue!
|
| MTU
|
short
|
see Open Connection Request 1
|
Open Connection Request 2
| Packet ID
|
Field Name
|
Field Type
|
Notes
|
| 0x07
|
Magic
|
MAGIC
|
|
| Server Address
|
address
|
|
| MTU
|
short
|
|
| Client GUID
|
Long
|
|
Open Connection Reply 2
| Packet ID
|
Field Name
|
Field Type
|
Notes
|
| 0x08
|
Magic
|
MAGIC
|
|
| Server GUID
|
Long
|
|
| Client Address
|
address
|
|
| MTU
|
short
|
|
| Encryption enabled?
|
boolean
|
|
Connection Request
| Packet ID
|
Field Name
|
Field Type
|
Notes
|
| 0x09
|
GUID
|
Long
|
|
| Time
|
Long
|
|
Connection Request Accepted
| Packet ID
|
Field Name
|
Field Type
|
Notes
|
| 0x10
|
Client address
|
address
|
|
| System index
|
short
|
Unknown what this does. 0 works as a value.
|
| Internal IDs
|
10x address
|
Unknown what these do. 255.255.255.255:19132 for all of them seems to work, any other address will probably work as well.
|
| Request time
|
Long
|
|
| Time
|
Long
|
|
New Incoming Connection
| Packet ID
|
Field Name
|
Field Type
|
Notes
|
| 0x13
|
Server address
|
address
|
|
| Internal address
|
address
|
Unknown what this is used for.
|
Disconnect
Incompatible Protocol
| Packet ID
|
Field Name
|
Field Type
|
Notes
|
| 0x19
|
Protocol
|
byte
|
|
| Magic
|
MAGIC
|
|
| Server GUID
|
Long
|
|
Unconnected Ping
| Packet ID
|
Field Name
|
Field Type
|
Notes
|
| 0x01, 0x02
|
Time
|
Long
|
|
| GUID
|
Long
|
|
Frame Set Packet
| Packet ID
|
Field Name
|
Field Type
|
Notes
|
| 0x80..0x8d
|
Sequence number
|
uint24le
|
|
| Frames
|
Flags
|
byte
|
Top 3 bits are reliability type, fourth bit is 1 when the frame is fragmented and part of a compound.
|
| Length IN BITS
|
unsigned short
|
Length of the body in bits.
|
| Reliable frame index
|
uint24le
|
only if reliable
|
| Sequenced frame index
|
uint24le
|
only if sequenced
|
| Order
|
Ordered frame index
|
uint24le
|
only if ordered
|
| Order channel
|
byte
|
| Fragment
|
Compound size
|
int
|
only if fragmented
|
| Compound ID
|
short
|
| Index
|
int
|
| Body
|
ceil(length/8) bytes
|
The reliability types are as follows:
| ID
|
Name
|
Reliable
|
Ordered
|
Sequenced
|
| 0
|
unreliable
|
|
|
|
| 1
|
unreliable sequenced
|
|
x
|
x
|
| 2
|
reliable
|
x
|
|
|
| 3
|
reliable ordered
|
x
|
x
|
|
| 4
|
reliable sequenced
|
x
|
x
|
x
|
| 5
|
unreliable (+ ACK receipt)
|
|
|
|
| 6
|
reliable (+ ACK receipt)
|
x
|
|
|
| 7
|
reliable ordered (+ ACK receipt)
|
x
|
x
|
|
Sequenced implies ordered.
Game Packet
| Packet ID
|
Field Name
|
Field Type
|
Notes
|
| 0xfe
|
Body
|
bytes
|
Single packet of the GAME protocol. The packet is usually compressed.
|
NACK
| Packet ID
|
Field Name
|
Field Type
|
Notes
|
| 0xa0
|
Record count
|
short
|
|
| Record
|
Single Sequence number?
|
boolean
|
False for range, True for no range
|
| No Range
|
Sequence number
|
uint24le
|
Number of sequence to not acknowledge
|
| Range
|
Start Sequence number
|
uint24le
|
| End Sequence number
|
uint24le
|
ACK
| Packet ID
|
Field Name
|
Field Type
|
Notes
|
| 0xc0
|
Record count
|
short
|
|
| Record
|
Single Sequence number?
|
boolean
|
False for range, True for no range
|
| No Range
|
Sequence number
|
uint24le
|
Number of sequence to acknowledge
|
| Range
|
Start Sequence number
|
uint24le
|
| End Sequence number
|
uint24le
|
