Pre-release protocol
This page documents the changes from the last stable Minecraft release (currently 1.9.2, protocol 109) to the current pre-release (currently 1.9.3-pre3, protocol 110). Note that this page contains bleeding-edge information that may not be completely or correctly documented.
One who wishes to commandeer the merging of this into Protocol when an update is made must be sure to respect any changes that may have occurred to the respective packets there.
Contents
Data types
No changes so far.
Packets
| ID | Packet name | Documentation | |
|---|---|---|---|
| Handshaking serverbound | |||
| 0x00 | Handshake | Current | Pre |
| Play clientbound | |||
| 0x09 | Update Block Entity | Current | Pre |
| 0x20 | Chunk data | Current | Pre |
| 0x46 | Update Sign (clientbound) | Current | |
| Sound Effect | Current | (unchanged) | |
| Player List Header And Footer | Current | (unchanged) | |
| Collect Item | Current | (unchanged) | |
| Entity Teleport | Current | (unchanged) | |
| Entity Properties | Current | (unchanged) | |
| Entity effect | Current | (unchanged) | |
New/modified data types
None so far.
MC|StopSound plugin channel
Used to implement the /stopsound command. Stops a sound that is currently playing on the client.
| Field name | Field type | Notes |
|---|---|---|
| Sound name | String | A sound effect name. If left empty, all sounds are stopped. |
| Sound category | String | Should be one of the sound categories used in Named Sound Effect, but if it's invalid or empty then it is (intentionally) treated as all sound categories. |
Emptiness of sound category or sound name can be combined, IE a empty sound name but a set sound category will stop all sounds in the given category.
Handshaking
Clientbound
No changes so far.
Serverbound
No changes so far.
Handshake
This causes the server to switch into the target state.
| Packet ID | State | Bound To | Field Name | Field Type | Notes |
|---|---|---|---|---|---|
| 0x00 | Handshaking | Server | Protocol Version | VarInt | See protocol version numbers (currently |
| Server Address | String | Hostname or IP, e.g. localhost or 127.0.0.1, that was used to connect. The Notchian server does not use this information. | |||
| Server Port | Unsigned Short | Default is 25565. The Notchian server does not use this information. | |||
| Next State | VarInt Enum | 1 for status, 2 for login |
Play
Clientbound
Update Block Entity
Essentially a block update on a block entity.
| Packet ID | State | Bound To | Field Name | Field Type | Notes |
|---|---|---|---|---|---|
| 0x09 | Play | Client | Location | Position | |
| Action | Unsigned Byte | The type of update to perform, see below | |||
| NBT Data | Optional NBT Tag | If not present then it's a TAG_END (0) |
Action field:
- 1: Set SpawnPotentials of a mob spawner
- 2: Set command block text (command and last execution status)
- 3: Set the level, primary, and secondary powers of a beacon
- 4: Set rotation and skin of mob head
- 5: Set type of flower in flower pot
- 6: Set base color and patterns on a banner
- 7: Set the data for a Structure tile entity
- 8: Set the destination for a end gateway
- 9: Set the text for a sign
Chunk Data
- See also: #Unload Chunk
The server only sends skylight information for chunk pillars in the Overworld, it's up to the client to know in which dimenison the player is currently located. You can also infer this information from the primary bitmask and the amount of uncompressed bytes sent. This also sends all tile entities in the chunk.
| Packet ID | State | Bound To | Field Name | Field Type | Notes |
|---|---|---|---|---|---|
| 0x20 | Play | Client | Chunk X | Int | Block coordinate divided by 16, rounded down |
| Chunk Z | Int | Block coordinate divided by 16, rounded down | |||
| Ground-Up Continuous | Boolean | This is true if the packet represents all chunk sections in this vertical chunk column, where the Primary Bit Mask specifies exactly which chunk sections are included, and which are air. | |||
| Primary Bit Mask | VarInt | Bitmask with bits set to 1 for every 16×16×16 chunk section whose data is included in Data. The least significant bit represents the chunk section at the bottom of the chunk column (from y=0 to y=15). | |||
| Size | VarInt | Size of Data in bytes, plus size of Biomes in bytes if present | |||
| Data | Array of Chunk Section | The length of the array is equal to the number of bits set in Primary Bit Mask. Chunks are sent bottom-to-top, i.e. the first chunk, if sent, extends from Y=0 to Y=15. | |||
| Biomes | Optional Byte Array | Only if Ground-Up Continuous: biome array, byte per XZ coordinate, 256 bytes total. | |||
| Number of tile entities | VarInt | Length of the following array | |||
| Tile entities | Array of NBT Tag | All tile entities in the chunk. Use the x, y, and z tags in the NBT to determine their positions. |
Serverbound
No changes so far.
Status
Clientbound
No changes so far.
Serverbound
No changes so far.
Login
Clientbound
No changes so far.
Serverbound
No changes so far.
