Difference between revisions of "Pre-release protocol"

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This page documents the changes from the [[Protocol|last stable Minecraft release]] (currently 1.5.2, protocol 61) to the current pre-release, 13w17a (protocol 64). Note that this page contains bleeding-edge information that may not be completely or correctly documented.
+
This page documents the changes from the [[Protocol|last stable Minecraft release]] (currently [[Protocol version numbers|1.16.5, protocol 754]]) to the current pre-release (currently [[Protocol version numbers|21w07a, protocol {{Snapshot PVN|1073741839}}]]). Note that this page contains bleeding-edge information that may not be completely or correctly documented.
  
He 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 occured to the respective packets there.
+
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.
  
== Protocol Version ==
+
== Contents ==
  
13w25a: Protocol version is now 71. Changed packet: [[Pre-release_protocol#0xC8|Increment Statistic (0xC8)]]
+
<div style="float:right;">__TOC__</div>
  
13w24b: Protocol version is now 70
+
=== Data types ===
  
13w24a: Protocol version is now 69. Changed functionality: [[Pre-release_protocol#0x04|Time Update (0x04)]]
+
No changes so far.
  
13w23b: Protocol version is now 68.
+
=== Packets ===
  
13w22a: Protocol version is now 67. New packet: [[Pre-release_protocol#0x2C|Entity Properties (0x2C)]]; Changed packets: [[Pre-release_protocol#0x03|Chat Message (0x03)]]
+
{| class="wikitable"
 +
! ID
 +
! Packet name
 +
!colspan="2"| Documentation
 +
|-
 +
!colspan="4"| Play clientbound
 +
{{PacketList|0x05|Sculk Vibration Signal|rel=added}}
 +
{{PacketList|{{change|0x05|0x06}}|Entity Animation (clientbound)|pre=unchanged}}
 +
{{PacketList|{{change|0x06|0x07}}|Statistics|pre=unchanged}}
 +
{{PacketList|{{change|0x07|0x08}}|Acknowledge Player Digging|pre=unchanged}}
 +
{{PacketList|{{change|0x08|0x09}}|Block Break Animation|pre=unchanged}}
 +
{{PacketList|{{change|0x09|0x0A}}|Block Entity Data|pre=unchanged}}
 +
{{PacketList|{{change|0x0A|0x0B}}|Block Action|pre=unchanged}}
 +
{{PacketList|{{change|0x0B|0x0C}}|Block Change|pre=unchanged}}
 +
{{PacketList|{{change|0x0C|0x0D}}|Boss Bar|pre=unchanged}}
 +
{{PacketList|{{change|0x0D|0x0E}}|Server Difficulty|pre=unchanged}}
 +
{{PacketList|{{change|0x0E|0x0F}}|Chat Message (clientbound)|pre=unchanged}}
 +
{{PacketList|0x10|Clear Titles|rel=added}}
 +
{{PacketList|{{change|0x0F|0x11}}|Tab-Complete (clientbound)|pre=unchanged}}
 +
{{PacketList|{{change|0x10|0x12}}|Declare Commands|pre=unchanged}}
 +
{{PacketList|0x11|Window Confirmation (clientbound)|pre=removed}}
 +
{{PacketList|{{change|0x12|0x13}}|Close Window (clientbound)|pre=unchanged}}
 +
{{PacketList|{{change|0x13|0x14}}|Window Items|pre=unchanged}}
 +
{{PacketList|{{change|0x14|0x15}}|Window Property|pre=unchanged}}
 +
{{PacketList|{{change|0x15|0x16}}|Set Slot|pre=unchanged}}
 +
{{PacketList|{{change|0x16|0x17}}|Set Cooldown|pre=unchanged}}
 +
{{PacketList|{{change|0x17|0x18}}|Plugin Message (clientbound)|pre=unchanged}}
 +
{{PacketList|{{change|0x18|0x19}}|Named Sound Effect|pre=unchanged}}
 +
{{PacketList|{{change|0x19|0x1A}}|Disconnect (play)|pre=unchanged}}
 +
{{PacketList|{{change|0x1A|0x1B}}|Entity Status|pre=unchanged}}
 +
{{PacketList|{{change|0x1B|0x1C}}|Explosion|pre=unchanged}}
 +
{{PacketList|{{change|0x1C|0x1D}}|Unload Chunk|pre=unchanged}}
 +
{{PacketList|{{change|0x1D|0x1E}}|Change Game State|pre=unchanged}}
 +
{{PacketList|{{change|0x1E|0x1F}}|Open Horse Window|pre=unchanged}}
 +
{{PacketList|0x20|Initialize World Border|rel=added}}
 +
{{PacketList|{{change|0x1F|0x21}}|Keep Alive (clientbound)|pre=unchanged}}
 +
{{PacketList|{{change|0x20|0x22}}|Chunk Data}}
 +
{{PacketList|{{change|0x21|0x23}}|Effect|pre=unchanged}}
 +
{{PacketList|{{change|0x22|0x24}}|Particle|pre=unchanged}}
 +
{{PacketList|{{change|0x23|0x25}}|Update Light}}
 +
{{PacketList|{{change|0x24|0x26}}|Join Game|pre=unchanged}}
 +
{{PacketList|{{change|0x25|0x27}}|Map Data}}
 +
{{PacketList|{{change|0x26|0x28}}|Trade List|pre=unchanged}}
 +
{{PacketList|{{change|0x27|0x29}}|Entity Position|pre=unchanged}}
 +
{{PacketList|{{change|0x28|0x2A}}|Entity Position and Rotation|pre=unchanged}}
 +
{{PacketList|{{change|0x29|0x2B}}|Entity Rotation|pre=unchanged}}
 +
{{PacketList|0x2A|Entity Movement|pre=removed}}
 +
{{PacketList|{{change|0x2B|0x2C}}|Vehicle Move (clientbound)|pre=unchanged}}
 +
{{PacketList|{{change|0x2C|0x2D}}|Open Book|pre=unchanged}}
 +
{{PacketList|{{change|0x2D|0x2E}}|Open Window|pre=unchanged}}
 +
{{PacketList|{{change|0x2E|0x2F}}|Open Sign Editor|pre=unchanged}}
 +
{{PacketList|{{change|0x2F|0x30}}|Craft Recipe Response|pre=unchanged}}
 +
{{PacketList|{{change|0x30|0x31}}|Player Abilities (clientbound)|pre=unchanged}}
 +
{{PacketList|0x31|Combat Event|pre=removed}}
 +
{{PacketList|0x32|End Combat Event|rel=added}}
 +
{{PacketList|0x33|Enter Combat Event|rel=added}}
 +
{{PacketList|0x34|Death Combat Event|rel=added}}
 +
{{PacketList|{{change|0x32|0x35}}|Player Info|pre=unchanged}}
 +
{{PacketList|{{change|0x33|0x36}}|Face Player|pre=unchanged}}
 +
{{PacketList|0x36|Destroy Entities}}|rel=removed}}
 +
{{PacketList|{{change|0x34|0x37}}|Player Position And Look (clientbound)}}
 +
{{PacketList|{{change|0x35|0x38}}|Unlock Recipes|pre=unchanged}}
 +
{{PacketList|0x39|Destroy Entity}}|rel=added}}
 +
{{PacketList|{{change|0x37|0x3A}}|Remove Entity Effect|pre=unchanged}}
 +
{{PacketList|{{change|0x38|0x3B}}|Resource Pack Send}}
 +
{{PacketList|{{change|0x39|0x3C}}|Respawn|pre=unchanged}}
 +
{{PacketList|{{change|0x3A|0x3D}}|Entity Head Look|pre=unchanged}}
 +
{{PacketList|{{change|0x3B|0x3E}}|Multi Block Change|pre=unchanged}}
 +
{{PacketList|{{change|0x3C|0x3F}}|Select Advancement Tab|pre=unchanged}}
 +
{{PacketList|0x40|Action Bar|rel=added}}
 +
{{PacketList|0x41|World Border Center|rel=added}}
 +
{{PacketList|0x42|World Border Lerp Size|rel=added}}
 +
{{PacketList|0x43|World Border Size |rel=added}}
 +
{{PacketList|0x44|World Border Warning Delay|rel=added}}
 +
{{PacketList|0x45|World Border Warning Reach|rel=added}}
 +
{{PacketList|{{change|0x3E|0x46}}|Camera|pre=unchanged}}
 +
{{PacketList|{{change|0x3F|0x47}}|Held Item Change (clientbound)|pre=unchanged}}
 +
{{PacketList|{{change|0x40|0x48}}|Update View Position|pre=unchanged}}
 +
{{PacketList|{{change|0x41|0x49}}|Update View Distance|pre=unchanged}}
 +
{{PacketList|{{change|0x42|0x4A}}|Spawn Position|pre=unchanged}}
 +
{{PacketList|{{change|0x43|0x4B}}|Display Scoreboard|pre=unchanged}}
 +
{{PacketList|{{change|0x44|0x4C}}|Entity Metadata|pre=unchanged}}
 +
{{PacketList|{{change|0x45|0x4D}}|Attach Entity|pre=unchanged}}
 +
{{PacketList|{{change|0x46|0x4E}}|Entity Velocity|pre=unchanged}}
 +
{{PacketList|{{change|0x47|0x4F}}|Entity Equipment|pre=unchanged}}
 +
{{PacketList|0x4F|Title|rel=removed}}
 +
{{PacketList|{{change|0x48|0x50}}|Set Experience|pre=unchanged}}
 +
{{PacketList|{{change|0x49|0x51}}|Update Health|pre=unchanged}}
 +
{{PacketList|{{change|0x4A|0x52}}|Scoreboard Objective|pre=unchanged}}
 +
{{PacketList|{{change|0x4B|0x53}}|Set Passengers|pre=unchanged}}
 +
{{PacketList|{{change|0x4C|0x54}}|Teams|pre=unchanged}}
 +
{{PacketList|{{change|0x4D|0x55}}|Update Score|pre=unchanged}}
 +
{{PacketList|0x56|Set Title SubTitle|rel=added}}
 +
{{PacketList|0x57|Time Update|pre=unchanged}}
 +
{{PacketList|0x58|Set Title Text|rel=added}}
 +
{{PacketList|0x59|Set Title Time|rel=added}}
 +
{{PacketList|{{change|0x50|0x5A}}|Entity Sound Effect|pre=unchanged}}
 +
{{PacketList|{{change|0x51|0x5B}}|Sound Effect|pre=unchanged}}
 +
{{PacketList|{{change|0x52|0x5C}}|Stop Sound|pre=unchanged}}
 +
{{PacketList|{{change|0x53|0x5D}}|Player List Header And Footer|pre=unchanged}}
 +
{{PacketList|{{change|0x54|0x5E}}|NBT Query Response|pre=unchanged}}
 +
{{PacketList|{{change|0x55|0x5F}}|Collect Item|pre=unchanged}}
 +
{{PacketList|{{change|0x56|0x60}}|Entity Teleport|pre=unchanged}}
 +
{{PacketList|{{change|0x57|0x61}}|Advancements|pre=unchanged}}
 +
{{PacketList|{{change|0x58|0x62}}|Entity Properties|pre=unchanged}}
 +
{{PacketList|{{change|0x59|0x63}}|Entity Effect|pre=unchanged}}
 +
{{PacketList|{{change|0x5A|0x64}}|Declare Recipes|pre=unchanged}}
 +
{{PacketList|{{change|0x5B|0x65}}|Tags}}
 +
|-
 +
!colspan="4"| Play serverbound
 +
{{PacketList|0x05|Client Settings}}
 +
|-
 +
!colspan="4"| Handshaking serverbound
 +
{{PacketList|0x00|Handshake}}
 +
|}
 +
 
 +
== New/modified data types ==
  
13w18b: Protocol version is now 65.
+
No changes so far.
  
13w16b: Protocol version is now 63. New packet: [[Pre-release_protocol#0x1B|Steer Vehicle (0x1B)]]
+
== Entity Metadata ==
  
13w16a: Protocol version is now 62. Changed packets: [[Pre-release_protocol#0x08|Update Health (0x08)]], [[Pre-release_protocol#0x17|Entity Action (0x17)]], [[Pre-release_protocol#0x27|Attach Entity (0x27)]], [[Pre-release_protocol#0xCA|Player Abilities (0xCA)]]
+
{{#vardefine:meta_prerelease|1}}
  
== New Packets ==
+
{{Warning2|Note that other entities have had metadata shifts due to these changes, not shown here.}}
  
{{anchor|0x1B}}
+
=== Entity ===
=== Steer Vehicle (0x1B) ===
 
''Client to Server''
 
  
Sent by client to steer the horse, minecart and boats.
+
{{metadata inherit|Entity}}
Horses listen to all directions, boats and minecarts only listen to the positive forward value in combination with the direction the player is looking in.
 
  
 
{| class="wikitable"
 
{| class="wikitable"
|-
+
! Index
| Packet ID
+
! Type
| Field Name
+
!style="width: 250px;" colspan="2"| Meaning
| Field Type
+
! Default
| Example
+
|-
| Notes
+
|rowspan="9"| {{Metadata id|}}
|-
+
|rowspan="9"| Byte
| rowspan="4" | 0x1B
+
! Bit mask
| Sideways
+
! Meaning
| float
+
|rowspan="9"| 0
| 0.98
+
|-
| Positive to the left of the player
+
| 0x01
|-
+
| Is on fire
| Forward
+
|-
| float
+
| 0x02
| -0.98
+
| Is crouching
| Positive forward
+
|-
|-
+
| 0x04
| Jump
+
| Unused (previously riding)
| bool
+
|-
| true
+
| 0x08
|  
+
| Is sprinting
|-
+
|-
| Unmount
+
| 0x10
| bool
+
| Is swimming
| false
+
|-
| True when leaving the vehicle
+
| 0x20
|-
+
| Is invisible
| Total Size:
+
|-
| colspan="4" | 11 bytes
+
| 0x40
|}
+
| has glowing effect
 +
|-
 +
| 0x80
 +
| Is flying with an {{Minecraft Wiki|elytra}}
 +
|-
 +
| {{Metadata id|}}
 +
| VarInt
 +
|colspan="2"| Air ticks
 +
| 300
 +
|-
 +
| {{Metadata id|}}
 +
| OptChat
 +
|colspan="2"| Custom name
 +
| empty
 +
|-
 +
| {{Metadata id|}}
 +
| Boolean
 +
|colspan="2"| Is custom name visible
 +
| false
 +
|-
 +
| {{Metadata id|}}
 +
| Boolean
 +
|colspan="2"| Is silent
 +
| false
 +
|-
 +
| {{Metadata id|}}
 +
| Boolean
 +
|colspan="2"| Has no gravity
 +
| false
 +
|-
 +
| {{Metadata id|}}
 +
| Pose
 +
|colspan="2"| Pose
 +
| STANDING
 +
|- {{added}}
 +
| {{Metadata id|added}}
 +
| VarInt
 +
|colspan="2"| Ticks frozen in powdered snow
 +
| 0
 +
|}
 +
 
 +
== Block Actions ==
 +
 
 +
No changes so far.
 +
 
 +
== Inventories ==
 +
 
 +
No changes so far.
 +
 
 +
== Plugin Channels ==
 +
 
 +
No changes so far.
 +
 
 +
== Play ==
 +
 
 +
=== Clientbound ===
 +
 
 +
==== Sculk Vibration Signal ====
 +
 
 +
{| class="wikitable" {{Added}}
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="4"| 0x05
 +
|rowspan="4"| Play
 +
|rowspan="4"| Client
 +
| Source Position
 +
| Position
 +
| Source position for the vibration.
 +
|-
 +
| Destination Identifier
 +
| Identifier
 +
| Identifier of the destination codec type.
 +
|-
 +
| Destination
 +
| Varies
 +
| Vanilla default destinations are a block position encoded as a [https://wiki.vg/Protocol#Data_types Position] for "block" or an entity id encoded as a VarInt for "entity".
 +
|-
 +
| Arrival Ticks
 +
| VarInt
 +
| Ticks for the signal to arrive at the destination.
 +
|}
 +
This packet shows a permanent particle.
 +
 
 +
==== Clear Titles====
  
{{anchor|0x2C}}
+
{| class="wikitable" {{Added}}
=== Entity Properties (0x2C) ===
+
! Packet ID
''Server to Client''
+
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|- {{ Added }}
 +
|rowspan="4"| 0x10
 +
|rowspan="4"| Play
 +
|rowspan="4"| Client
 +
|- {{ Added }}
 +
| Reset
 +
| Boolean
 +
|
 +
|-
 +
|}
  
'''Note''': The server sends this packet to inform the user of its movement speed. Users move far too fast when this packet is not sent.
+
==== Initialize World Border ====
  
 
{| class="wikitable"
 
{| class="wikitable"
|-
+
! Packet ID
| Packet ID
+
! State
| Field Name
+
! Bound To
| Field Type
+
! Field Name
| Example
+
! Field Type
| Notes
+
! Notes
|-
+
|- {{ Added }}
| rowspan="4" | 0x2C
+
|rowspan="8"| 0x20
| EntityID
+
|rowspan="8"| Play
| int
+
|rowspan="8"| Client
| 195
+
| X
| ?
+
| Double
|-
+
|
| Properties Count
+
|- {{ Added }}
| int
+
| Z
| 3
+
| Double
| Number of string/data pairs that follow. The remaining fields here are repeated this number of times.
+
|
|-
+
|- {{ Added }}
| Key
+
| Old Diameter
| string16
+
| Double
| "generic.Maxhealth"
+
| Current length of a single side of the world border, in meters.
|  
+
|- {{ Added }}
|-
+
| New Diameter
| Value
+
| Double
| double
+
| Target length of a single side of the world border, in meters.
| 20.0
+
|- {{ Added }}
|  
+
| Speed
|-
+
| VarLong
| Total Size:
+
| Number of real-time ''milli''seconds until New Diameter is reached. It appears that Notchian server does not sync world border speed to game ticks, so it gets out of sync with server lag. If the world border is not moving, this is set to 0.
| colspan="4" | ? bytes
+
|- {{ Added }}
|}
+
| Portal Teleport Boundary
 +
| VarInt
 +
| Resulting coordinates from a portal teleport are limited to ±value. Usually 29999984.
 +
|- {{ Added }}
 +
| Warning Blocks
 +
| VarInt
 +
| In meters.
 +
|- {{ Added }}
 +
| Warning Time
 +
| VarInt
 +
| In seconds as set by <code>/worldborder warning time</code>.
 +
|- {{ Added }}
 +
|}
 +
 
 +
The Notchian client determines how solid to display the warning by comparing to whichever is higher, the warning distance or whichever is lower, the distance from the current diameter to the target diameter or the place the border will be after warningTime seconds. In pseudocode:
 +
 
 +
<syntaxhighlight lang="java">
 +
distance = max(min(resizeSpeed * 1000 * warningTime, abs(targetDiameter - currentDiameter)), warningDistance);
 +
if (playerDistance < distance) {
 +
    warning = 1.0 - playerDistance / distance;
 +
} else {
 +
    warning = 0.0;
 +
}
 +
</syntaxhighlight>
 +
 
 +
==== Chunk Data ====
 +
{{Main|Chunk Format}}
 +
{{See also|#Unload Chunk}}
 +
 
 +
{{Need Info|How do biomes work now? The biome change happened at the same time as the seed change, but it's not clear how/if biomes could be computed given that it's not the actual seed...  ([https://www.reddit.com/r/Mojira/comments/e5at6i/a_discussion_for_the_changes_to_how_biomes_are/ /r/mojira discussion] which notes that it seems to be some kind of interpolation, and 3D biomes are only used in the nether)}}
 +
 
 +
The server only sends skylight information for chunk pillars in the {{Minecraft Wiki|Overworld}}, it's up to the client to know in which dimension the player is currently located. You can also infer this information from the primary bitmask and the amount of uncompressed bytes sent.  This packet also sends all block entities in the chunk (though sending them is not required; it is still legal to send them with [[#Update Block Entity|Update Block Entity]] later).
  
Known values:
 
 
{| class="wikitable"
 
{| class="wikitable"
|-
+
! Packet ID
| Key
+
! State
| Default
+
! Bound To
| Min
+
! Field Name
| Max
+
! Field Type
| Label
+
! Notes
|-
+
|-
| generic.maxHealth
+
|rowspan="13"| {{change|0x20|0x22}}
| 20.0
+
|rowspan="13"| Play
| 0.0
+
|rowspan="13"| Client
| Double.MaxValue
+
| Chunk X
| Max Health
+
| Int
|-
+
| Chunk coordinate (block coordinate divided by 16, rounded down)
| generic.followRange
+
|-
| 32.0
+
| Chunk Z
| 0.0
+
| Int
| 2048.0
+
| Chunk coordinate (block coordinate divided by 16, rounded down)
| Follow Range
+
|- {{removed}}
|-
+
| Full chunk
| generic.knockbackResistance
+
| Boolean
| 0.0
+
| See [[Chunk Format#Full chunk|Chunk Format]]
| 0.0
+
|- {{removed}}
| 1.0
+
| Primary Bit Mask
| Knockback Resistance
+
| 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).
| generic.movementSpeed
+
|- {{added}}
| 0.699999988079071
+
| Bit Mask Length
| 0.0
+
| VarInt
| Double.MaxValue
+
| Length of the following array
| Movement Speed
+
|- {{added}}
|-
+
| Primary Bit Mask
| generic.attackDamage
+
| Array of Long
| 2.0
+
| BitSet with bits (world height in blocks / 16) 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 the lowest y to 15 blocks above).
| 0.0
+
|-
| Double.MaxValue
+
| Heightmaps
|  
+
| [[NBT]]
|-
+
| Compound containing one long array named <code>MOTION_BLOCKING</code>, which is a heightmap for the highest solid block at each position in the chunk (as a compacted long array with 256 entries at 9 bits per entry totaling 36 longs). The Notchian server also adds a <code>WORLD_SURFACE</code> long array, the purpose of which is unknown, but it's not required for the chunk to be accepted.
| horse.jumpStrength
+
|-
| 0.7
+
| Biomes length
| 0.0
+
| {{change|Optional|}} VarInt
| 2.0
+
| Size of the following array; should always be 1024. {{change|Not present if full chunk is false.|}}
| Jump Strength
+
|-
|-
+
| Biomes
| zombie.spawnReinforcements
+
| {{change|Optional|}} Array of VarInt
| 0.0
+
| 1024 biome IDs, ordered by x then z then y, in 4&times;4&times;4 blocks.  {{change|Not present if full chunk is false.|}}  See [[Chunk Format#Biomes|Chunk Format § Biomes]].
| 0.0
+
|-
| 1.0
+
| Size
| Spawn Reinforcements Chance
+
| VarInt
|}
+
| Size of Data in bytes
 +
|-
 +
| Data
 +
| Byte array
 +
| See [[Chunk Format#Data structure|data structure]] in Chunk Format
 +
|-
 +
| Number of block entities
 +
| VarInt
 +
| Number of elements in the following array
 +
|-
 +
| Block entities
 +
| Array of [[NBT|NBT Tag]]
 +
| All block entities in the chunk.  Use the x, y, and z tags in the NBT to determine their positions.
 +
|}
  
== Changed Packets ==
+
Note that the Notchian client requires an [[#Update View Position|Update View Position]] packet when it crosses a chunk border, otherwise it'll only display render distance + 2 chunks around the chunk it spawned in.
  
{{anchor|0x03}}
+
The compacted array format has been adjusted so that individual entries no longer span across multiple longs, affecting the main data array and heightmaps.
=== Chat Message (0x03) ===
 
  
''Client to Server''
+
New format, 5 bits per block, containing the following references to blocks in a palette (not shown): <span style="border: solid 2px hsl(0, 90%, 60%)">1</span><span style="border: solid 2px hsl(30, 90%, 60%)">2</span><span style="border: solid 2px hsl(60, 90%, 60%)">2</span><span style="border: solid 2px hsl(90, 90%, 60%)">3</span><span style="border: solid 2px hsl(120, 90%, 60%)">4</span><span style="border: solid 2px hsl(150, 90%, 60%)">4</span><span style="border: solid 2px hsl(180, 90%, 60%)">5</span><span style="border: solid 2px hsl(210, 90%, 60%)">6</span><span style="border: solid 2px hsl(240, 90%, 60%)">6</span><span style="border: solid 2px hsl(270, 90%, 60%)">4</span><span style="border: solid 2px hsl(300, 90%, 60%)">8</span><span style="border: solid 2px hsl(330, 90%, 60%)">0</span><span style="border: solid 2px hsl(0, 90%, 30%)">7</span><span style="border: solid 2px hsl(30, 90%, 30%)">4</span><span style="border: solid 2px hsl(60, 90%, 30%)">3</span><span style="border: solid 2px hsl(90, 90%, 30%)">13</span><span style="border: solid 2px hsl(120, 90%, 30%)">15</span><span style="border: solid 2px hsl(150, 90%, 30%)">16</span><span style="border: solid 2px hsl(180, 90%, 30%)">9</span><span style="border: solid 2px hsl(210, 90%, 30%)">14</span><span style="border: solid 2px hsl(240, 90%, 30%)">10</span><span style="border: solid 2px hsl(270, 90%, 30%)">12</span><span style="border: solid 2px hsl(300, 90%, 30%)">0</span><span style="border: solid 2px hsl(330, 90%, 30%)">2</span>
  
Unchanged
+
<code>0020863148418841</code> <code><span style="outline: dashed 2px black">0000</span><span style="outline: solid 2px hsl(330, 90%, 60%)">00000</span><span style="outline: solid 2px hsl(300, 90%, 60%)">01000</span><span style="outline: solid 2px hsl(270, 90%, 60%)">00100</span><span style="outline: solid 2px hsl(240, 90%, 60%)">00110</span><span style="outline: solid 2px hsl(210, 90%, 60%)">00110</span><span style="outline: solid 2px hsl(180, 90%, 60%)">00101</span><span style="outline: solid 2px hsl(150, 90%, 60%)">00100</span><span style="outline: solid 2px hsl(120, 90%, 60%)">00100</span><span style="outline: solid 2px hsl(90, 90%, 60%)">00011</span><span style="outline: solid 2px hsl(60, 90%, 60%)">00010</span><span style="outline: solid 2px hsl(30, 90%, 60%)">00010</span><span style="outline: solid 2px hsl(0, 90%, 60%)">00001</span></code><br>
 +
<code>01018A7260F68C87</code> <code><span style="outline: dashed 2px black">0000</span><span style="outline: solid 2px hsl(330, 90%, 30%)">00010</span><span style="outline: solid 2px hsl(300, 90%, 30%)">00000</span><span style="outline: solid 2px hsl(270, 90%, 30%)">01100</span><span style="outline: solid 2px hsl(240, 90%, 30%)">01010</span><span style="outline: solid 2px hsl(210, 90%, 30%)">01110</span><span style="outline: solid 2px hsl(180, 90%, 30%)">01001</span><span style="outline: solid 2px hsl(150, 90%, 30%)">10000</span><span style="outline: solid 2px hsl(120, 90%, 30%)">01111</span><span style="outline: solid 2px hsl(90, 90%, 30%)">01101</span><span style="outline: solid 2px hsl(60, 90%, 30%)">00011</span><span style="outline: solid 2px hsl(30, 90%, 30%)">00100</span><span style="outline: solid 2px hsl(0, 90%, 30%)">00111</span></code>
  
''Server to Client''
+
==== Entity Movement ====
  
The chat string must now be a valid JSON object:
+
This packet may be used to initialize an entity.
  
    {"translate":"chat.type.announcement","using":["Server","hi"]}
+
For player entities, either this packet or any move/look packet is sent every game tick. So the meaning of this packet is basically that the entity did not move/look since the last such packet.
    {"color":"gray","italic":true,"translate":"chat.type.admin","using":["Server",{"translate":"commands.save.success"}]}
 
    {"text":"§aOld style chat"}
 
[https://gist.github.com/Dinnerbone/5631634 Original Gist from Dinnerbone]
 
  
Where translate is one of the following:
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|- {{removed}}
 +
| 0x2A
 +
| Play
 +
| Client
 +
| Entity ID
 +
| VarInt
 +
|
 +
|}
  
    chat.type.admin: [%s: %s]
+
==== Update Light ====
    chat.type.announcement: [%s] %s
 
    chat.type.emote: * %s %s
 
    chat.type.text: <%s> %s
 
  
{{anchor|0x04}}
+
Updates light levels for a chunk.
=== 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.
+
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
!colspan="2"| Field Name
 +
!colspan="2"| Field Type
 +
! Notes
 +
|-
 +
|rowspan="21"| {{change|0x23|0x25}}
 +
|rowspan="21"| Play
 +
|rowspan="21"| Client
 +
|colspan="2"| Chunk X
 +
|colspan="2"| VarInt
 +
| Chunk coordinate (block coordinate divided by 16, rounded down)
 +
|-
 +
|colspan="2"| Chunk Z
 +
|colspan="2"| VarInt
 +
| Chunk coordinate (block coordinate divided by 16, rounded down)
 +
|-
 +
|colspan="2"| Trust Edges
 +
|colspan="2"| Boolean
 +
| If edges should be trusted for light updates.
 +
|- {{removed}}
 +
|colspan="2"| Sky Light Mask
 +
|colspan="2"| VarInt
 +
| Mask containing 18 bits, with the lowest bit corresponding to chunk section -1 (in the void, y=-16 to y=-1) and the highest bit for chunk section 16 (above the world, y=256 to y=271)
 +
|- {{removed}}
 +
|colspan="2"| Block Light Mask
 +
|colspan="2"| VarInt
 +
| Mask containing 18 bits, with the same order as sky light
 +
|- {{removed}}
 +
|colspan="2"| Empty Sky Light Mask
 +
|colspan="2"| VarInt
 +
| Mask containing 18 bits, which indicates sections that have 0 for all their sky light values.  If a section is set in both this mask and the main sky light mask, it is ignored for this mask and it is included in the sky light arrays (the notchian server does not create such masks).  If it is only set in this mask, it is not included in the sky light arrays.
 +
|- {{removed}}
 +
|colspan="2"| Empty Block Light Mask
 +
|colspan="2"| VarInt
 +
| Mask containing 18 bits, which indicates sections that have 0 for all their block light values.  If a section is set in both this mask and the main block light mask, it is ignored for this mask and it is included in the block light arrays (the notchian server does not create such masks).  If it is only set in this mask, it is not included in the block light arrays.
 +
|- {{Added}}
 +
|colspan="2"| Length 1
 +
|colspan="2"| VarInt
 +
| Length of the following array
 +
|- {{Added}}
 +
|colspan="2"| Sky Light Mask
 +
|colspan="2"| Array of Long
 +
| BitSet containing bits for each sections in the world + 2 (lowest bit 16-1 blocks below min world height, highest 1-16 above max world height)
 +
|- {{Added}}
 +
|colspan="2"| Length 2
 +
|colspan="2"| VarInt
 +
| Length of the following array
 +
|- {{Added}}
 +
|colspan="2"| Block Light Mask
 +
|colspan="2"| Array of Long
 +
| BitSet containing bits for each sections in the world + 2, same order as sky light
 +
|- {{Added}}
 +
|colspan="2"| Length 3
 +
|colspan="2"| VarInt
 +
| Length of the following array
 +
|- {{Added}}
 +
|colspan="2"| Empty Sky Light Mask
 +
|colspan="2"| Array of Long
 +
| BitSet containing a variable amount of bits (see sky/block light) which indicates sections that have 0 for all their sky light values
 +
|- {{Added}}
 +
|colspan="2"| Length 4
 +
|colspan="2"| VarInt
 +
| Length of the following array
 +
|- {{Added}}
 +
|colspan="2"| Empty Block Light Mask
 +
|colspan="2"| Array of Long
 +
| BitSet containing a variable amount of bits (see sky/block light) which indicates sections that have 0 for all their block light values
 +
|- {{added}}
 +
|colspan="2"| Sky Light array count
 +
|colspan="2"| VarInt
 +
| Number of entries in the following array
 +
|-
 +
|rowspan="2"| Sky Light arrays
 +
| Length
 +
|rowspan="2"| Array
 +
| VarInt
 +
| Length of the following array in bytes (always 2048)
 +
|-
 +
| Sky Light array
 +
| Array of 2048 bytes
 +
| There is 1 array for each bit set to true in the sky light mask, starting with the lowest value.  Half a byte per light value.
 +
|- {{added}}
 +
|colspan="2"| Block Light array count
 +
|colspan="2"| VarInt
 +
| Number of entries in the following array
 +
|-
 +
|rowspan="2"| Block Light arrays
 +
| Length
 +
|rowspan="2"| Array
 +
| VarInt
 +
| Length of the following array in bytes (always 2048)
 +
|-
 +
| Block Light array
 +
| Array of 2048 bytes
 +
| There is 1 array for each bit set to true in the block light mask, starting with the lowest value.  Half a byte per light value.
 +
|}
  
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 the time by <code>20</code> every second.
+
==== Map Data ====
 +
 
 +
Updates a rectangular area on a {{Minecraft Wiki|map}} item.
  
 
{| class="wikitable"
 
{| class="wikitable"
|-
+
! Packet ID
! | Packet ID
+
! State
! | Field Name
+
! Bound To
! | Field Type
+
!colspan="2"| Field Name
! | Example
+
!colspan="2"| Field Type
! | Notes
+
! Notes
|-
+
|-
| rowspan="2" | 0x04
+
|rowspan="18"| {{change|0x25|0x27}}
| Age of the world
+
|rowspan="18"| Play
| long
+
|rowspan="18"| Client
| 45464654
+
|colspan="2"| Map ID
| In ticks; not changed by server commands
+
|colspan="2"| VarInt
|-
+
| Map ID of the map being modified
| Time of Day
+
|-
| long
+
|colspan="2"| Scale
| 21321
+
|colspan="2"| Byte
| The world (or region) time, in ticks. '''If negative the sun will stop moving at the Math.abs of the time.'''
+
| From 0 for a fully zoomed-in map (1 block per pixel) to 4 for a fully zoomed-out map (16 blocks per pixel)
|-
+
|- {{removed}}
! | Total Size:
+
|colspan="2"| Tracking Position
| colspan="4" | 17 Bytes
+
|colspan="2"| Boolean
|}
+
| Specifies whether player and item frame icons are shown
 +
|-
 +
|colspan="2"| Locked
 +
|colspan="2"| Boolean
 +
| True if the map has been locked in a cartography table
 +
|-
 +
|- {{added}}
 +
|colspan="2"| Tracking Position
 +
|colspan="2"| Boolean
 +
| Specifies whether player and item frame icons are shown
 +
|-
 +
|colspan="2"| Icon Count
 +
|colspan="2"| VarInt
 +
| Number of elements in the following array. {{change||Only present if "Tracking Position" is true.}}
 +
|-
 +
|rowspan="6"| Icon
 +
| Type
 +
|rowspan="6"| Array
 +
| VarInt enum
 +
| See below
 +
|-
 +
| X
 +
| Byte
 +
| Map coordinates: -128 for furthest left, +127 for furthest right
 +
|-
 +
| Z
 +
| Byte
 +
| Map coordinates: -128 for highest, +127 for lowest
 +
|-
 +
| Direction
 +
| Byte
 +
| 0-15
 +
|-
 +
| Has Display Name
 +
| Boolean
 +
|
 +
|-
 +
| Display Name
 +
| Optional [[Chat]]
 +
| Only present if previous Boolean is true
 +
|-
 +
|colspan="2"| Columns
 +
|colspan="2"| Unsigned Byte
 +
| Number of columns updated
 +
|-
 +
|colspan="2"| Rows
 +
|colspan="2"| Optional Byte
 +
| Only if Columns is more than 0; number of rows updated
 +
|-
 +
|colspan="2"| X
 +
|colspan="2"| Optional Byte
 +
| Only if Columns is more than 0; x offset of the westernmost column
 +
|-
 +
|colspan="2"| Z
 +
|colspan="2"| Optional Byte
 +
| Only if Columns is more than 0; z offset of the northernmost row
 +
|-
 +
|colspan="2"| Length
 +
|colspan="2"| Optional VarInt
 +
| Only if Columns is more than 0; length of the following array
 +
|-
 +
|colspan="2"| Data
 +
|colspan="2"| Optional Array of Unsigned Byte
 +
| Only if Columns is more than 0; see {{Minecraft Wiki|Map item format}}
 +
|}
 +
 
 +
For icons, a direction of 0 is a vertical icon and increments by 22.5&deg; (360/16).
 +
 
 +
Types are based off of rows and columns in <code>map_icons.png</code>:
  
{{anchor|0x08}}
+
{| class="wikitable"
=== Update Health (0x08) ===
+
|-
''Server to Client''
+
! Icon type
 +
! Result
 +
|-
 +
| 0
 +
| White arrow (players)
 +
|-
 +
| 1
 +
| Green arrow (item frames)
 +
|-
 +
| 2
 +
| Red arrow
 +
|-
 +
| 3
 +
| Blue arrow
 +
|-
 +
| 4
 +
| White cross
 +
|-
 +
| 5
 +
| Red pointer
 +
|-
 +
| 6
 +
| White circle (off-map players)
 +
|-
 +
| 7
 +
| Small white circle (far-off-map players)
 +
|-
 +
| 8
 +
| Mansion
 +
|-
 +
| 9
 +
| Temple
 +
|-
 +
| 10
 +
| White Banner
 +
|-
 +
| 11
 +
| Orange Banner
 +
|-
 +
| 12
 +
| Magenta Banner
 +
|-
 +
| 13
 +
| Light Blue Banner
 +
|-
 +
| 14
 +
| Yellow Banner
 +
|-
 +
| 15
 +
| Lime Banner
 +
|-
 +
| 16
 +
| Pink Banner
 +
|-
 +
| 17
 +
| Gray Banner
 +
|-
 +
| 18
 +
| Light Gray Banner
 +
|-
 +
| 19
 +
| Cyan Banner
 +
|-
 +
| 20
 +
| Purple Banner
 +
|-
 +
| 21
 +
| Blue Banner
 +
|-
 +
| 22
 +
| Brown Banner
 +
|-
 +
| 23
 +
| Green Banner
 +
|-
 +
| 24
 +
| Red Banner
 +
|-
 +
| 25
 +
| Black Banner
 +
|-
 +
| 26
 +
| Treasure marker
 +
|}
  
Sent by the server to update/set the health of the player it is sent to. Added in protocol version 5.
+
==== Combat Event ====
  
Food saturation acts as a food "overcharge". Food values will not decrease while the saturation is over zero. Players logging in automatically get a saturation of 5.0. Eating food increases the saturation as well as the food bar.
+
Originally used for metadata for twitch streaming circa 1.8.  Now only used to display the game over screen (with enter combat and end combat completely ignored by the Notchain client)
  
 
{| class="wikitable"
 
{| class="wikitable"
|-
+
! Packet ID
| Packet ID
+
! State
| Field Name
+
! Bound To
| Field Type
+
!colspan="2"| Field Name
| Example
+
! Field Type
| Notes
+
! Notes
|-
+
|- {{Removed}}
| rowspan="3" | 0x08
+
|rowspan="8"| 0x31
| Health
+
|rowspan="8"| Play
| '''float'''
+
|rowspan="8"| Client
| '''20.0'''
+
|colspan="2"| Event
| 0 or less = dead, 20 = full HP
+
| VarInt Enum
|-
+
| Determines the layout of the remaining packet.
| Food
+
|- {{Removed}}
| short
+
! Event
| 20
+
! Field Name
| 0 - 20
+
!
|-
+
!
| Food Saturation
+
|- {{Removed}}
| float
+
| 0: enter combat
| 5.0
+
| ''no fields''
| Seems to vary from 0.0 to 5.0 in integer increments
+
| ''no fields''
|-
+
|
| Total Size:
+
|- {{Removed}}
| colspan="4" | 11 bytes
+
|rowspan="2"| 1: end combat
|}
+
| Duration
 +
| VarInt
 +
| Length of the combat in ticks.
 +
|- {{Removed}}
 +
| Entity ID
 +
| Int
 +
| ID of the primary opponent of the ended combat, or -1 if there is no obvious primary opponent.
 +
|- {{Removed}}
 +
|rowspan="3"| 2: entity dead
 +
| Player ID
 +
| VarInt
 +
| Entity ID of the player that died (should match the client's entity ID).
 +
|- {{Removed}}
 +
| Entity ID
 +
| Int
 +
| The killing entity's ID, or -1 if there is no obvious killer.
 +
|- {{Removed}}
 +
| Message
 +
| [[Chat]]
 +
| The death message.
 +
|}
  
{{anchor|0x13}}
+
==== End Combat Event ====
=== Entity Action (0x13) ===
 
''Client to Server''
 
  
Sent at least when crouching, leaving a bed, or sprinting.
+
Unused by the Notchain client.
To send action animation to client use 0x28.
 
The client will send this with Action ID = 3 when "Leave Bed" is clicked.
 
  
 
{| class="wikitable"
 
{| class="wikitable"
|-
+
! Packet ID
| Packet ID
+
! State
| Field Name
+
! Bound To
| Field Type
+
!colspan="2"| Field Name
| Example
+
! Field Type
| Notes
+
! Notes
|-
+
|- {{Added}}
| rowspan="3" | 0x13
+
|rowspan="8"| 0x32
| EID
+
|rowspan="8"| Play
| int
+
|rowspan="8"| Client
| <code>55534</code>
+
| Duration
| Player ID
+
| VarInt
|-
+
| Length of the combat in ticks.
| Action ID
+
|- {{Added}}
| byte
+
| Entity ID
| <code>1</code>
+
| Int
| The ID of the action, see below.
+
| ID of the primary opponent of the ended combat, or -1 if there is no obvious primary opponent.
|-
+
|- {{Added}}
| '''Unknown'''
+
|}
| int
 
| <code>0</code>
 
| Something to do with horses. Ranged from 0 -> 90
 
|-
 
| Total Size:
 
| colspan="4" | 10 bytes
 
|}
 
  
Action ID can be one of the following values:
+
==== Enter Combat Event ====
 +
 
 +
Unused by the Notchain client.
  
 
{| class="wikitable"
 
{| class="wikitable"
|-
+
! Packet ID
! ID
+
! State
! Action
+
! Bound To
|-
+
!colspan="2"| Field Name
| 1
+
! Field Type
| Crouch
+
! Notes
|-
+
|- {{Added}}
| 2
+
|rowspan="8"| 0x33
| Uncrouch
+
|rowspan="8"| Play
|-
+
|rowspan="8"| Client
| 3
+
|}
| Leave bed
 
|-
 
| 4
 
| Start sprinting
 
|-
 
| 5
 
| Stop sprinting
 
|}
 
  
{{anchor|0x27}}
 
=== Attach Entity (0x27) ===
 
''Server to Client''
 
  
This packet is sent when a player has been attached to an entity (e.g. Minecart)
+
==== Death Combat Event ====
 +
 
 +
Used to send a respawn screen.
  
 
{| class="wikitable"
 
{| class="wikitable"
|-
+
! Packet ID
| Packet ID
+
! State
| Field Name
+
! Bound To
| Field Type
+
!colspan="2"| Field Name
| Example
+
! Field Type
| Notes
+
! Notes
|-
+
|- {{Added}}
| rowspan="3" | 0x27
+
|rowspan="8"| 0x34
| Entity ID
+
|rowspan="8"| Play
| int
+
|rowspan="8"| Client
| <code>1298</code>
+
| Player ID
| The player entity ID being attached
+
| VarInt
|-
+
| Entity ID of the player that died (should match the client's entity ID).
| Vehicle ID
+
|- {{Added}}
| int
+
| Entity ID
| <code>1805</code>
+
| Int
| The vehicle entity ID attached to (-1 for unattaching)
+
| The killing entity's ID, or -1 if there is no obvious killer.
|-
+
|- {{Added}}
| '''Leash'''
+
| Message
| boolean
+
| [[Chat]]
| <code>false</code>
+
| The death message.
| If set to true, leashes the entity to the vehicle
+
|}
|-
 
| Total Size:
 
| colspan="4" | 10 bytes
 
|}
 
  
{{anchor|0xC8}}
+
==== Player Position And Look (clientbound) ====  
=== Increment Statistic (0xC8) ===
+
 
''Server to Client''
+
Updates the player's position on the server. This packet will also close the “Downloading Terrain” screen when joining/respawning.
 +
 
 +
If the distance between the last known position of the player on the server and the new position set by this packet is greater than 100 meters, the client will be kicked for “You moved too quickly :( (Hacking?)”.
 +
 
 +
Also if the fixed-point number of X or Z is set greater than <code>3.2E7D</code> the client will be kicked for “Illegal position”.
 +
 
 +
Yaw is measured in degrees, and does not follow classical trigonometry rules. The unit circle of yaw on the XZ-plane starts at (0, 1) and turns counterclockwise, with 90 at (-1, 0), 180 at (0, -1) and 270 at (1, 0). Additionally, yaw is not clamped to between 0 and 360 degrees; any number is valid, including negative numbers and numbers greater than 360.
 +
 
 +
Pitch is measured in degrees, where 0 is looking straight ahead, -90 is looking straight up, and 90 is looking straight down.
  
 
{| class="wikitable"
 
{| class="wikitable"
|-
+
! Packet ID
| Packet ID
+
! State
| Field Name
+
! Bound To
| Field Type
+
! Field Name
| Example
+
! Field Type
| Notes
+
! Notes
|-
+
|-
| rowspan="2" | 0xC8
+
|rowspan="8"| {{change|0x34|0x38}}
| Statistic ID
+
|rowspan="8"| Play
| int
+
|rowspan="8"| Client
| 1003
+
| X
| The ID of the statistic. See [http://www.minecraftforum.net/viewtopic.php?f=1020&t=295360 List of statistics].
+
| Double
|-
+
| Absolute or relative position, depending on Flags.
| Amount
+
|-
| '''int'''
+
| Y
| 1
+
| Double
| The amount to increment the statistic.
+
| Absolute or relative position, depending on Flags.
|-
+
|-
| Total Size:
+
| Z
| colspan="4" | 9 bytes
+
| Double
|}
+
| Absolute or relative position, depending on Flags.
 +
|-
 +
| Yaw
 +
| Float
 +
| Absolute or relative rotation on the X axis, in degrees.
 +
|-
 +
| Pitch
 +
| Float
 +
| Absolute or relative rotation on the Y axis, in degrees.
 +
|-
 +
| Flags
 +
| Byte
 +
| Bit field, see below.
 +
|-
 +
| Teleport ID
 +
| VarInt
 +
| Client should confirm this packet with [[#Teleport Confirm|Teleport Confirm]] containing the same Teleport ID.
 +
|- {{added}}
 +
| Dismount Vehicle
 +
| Boolean
 +
| True if the player should dismount their vehicle.
 +
|}
  
{{anchor|0xCA}}
+
About the Flags field:
=== Player Abilities (0xCA) ===
 
''Two-Way''
 
  
The latter 2 bytes are used to indicate the walking and flying speeds respectively, while the first byte is used to determine the value of 4 booleans.
+
<Dinnerbone> It's a bitfield, X/Y/Z/Y_ROT/X_ROT. If X is set, the x value is relative and not absolute.
 
The flags are whether damage is disabled (god mode, 8, bit 3), whether the player can fly (4, bit 2), whether the player is flying (2, bit 1), and whether the player is in creative mode (1, bit 0).
 
 
To get the values of these booleans, simply AND (&) the byte with 1,2,4 and 8 respectively, to get the 0 or 1 bitwise value. To set them OR (|) them with their repspective masks.
 
The vanilla client sends this packet when the player starts/stops flying with the second parameter changed accordingly. All other parameters are ignored by the vanilla server.
 
  
 
{| class="wikitable"
 
{| class="wikitable"
|-
+
|-
| Packet ID
+
! Field
| Field Name
+
! Bit
| Field Type
+
|-
| Example
+
| X
| Notes
+
| 0x01
|-
+
|-
| rowspan="3" | 0xCA
+
| Y
| Flags
+
| 0x02
| byte
+
|-
| 5
+
| Z
|
+
| 0x04
|-
+
|-
| Flying speed
+
| Y_ROT
| '''float'''
+
| 0x08
| '''0.05'''
+
|-
| previous integer value divided by 250
+
| X_ROT
|-
+
| 0x10
| Walking speed
+
|}
| '''float'''
+
 
| '''0.1'''
+
==== Destroy Entity ====
| previous integer value divided by 250
+
 
|-
+
Sent by the server when {{change|a list of entities|an entity}} is to be destroyed on the client.
| Total Size:
+
 
| colspan="4" | 10 bytes
+
{| class="wikitable"
|}
+
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="4"| 0x36
 +
|rowspan="4"| Play
 +
|rowspan="4"| Client
 +
|- {{removed}}
 +
| Count
 +
| VarInt
 +
| Number of elements in the following array.
 +
|- {{Removed}}
 +
| Array of VarInt
 +
| The list of entities of destroy.
 +
|- {{Added}}
 +
| Entity ID
 +
| VarInt
 +
|}
 +
 
 +
==== Resource Pack Send ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="4"| {{change|0x38|0x3B}}
 +
|rowspan="4"| Play
 +
|rowspan="4"| Client
 +
| URL
 +
| String (32767)
 +
| The URL to the resource pack.
 +
|-
 +
| Hash
 +
| String (40)
 +
| A 40 character hexadecimal and lowercase [[wikipedia:SHA-1|SHA-1]] hash of the resource pack file. (must be lower case in order to work)<br />If it's not a 40 character hexadecimal string, the client will not use it for hash verification and likely waste bandwidth — but it will still treat it as a unique id
 +
|- {{Added}}
 +
| Forced
 +
| Boolean
 +
| The notchian client will be forced to use the resource pack from the server. If they decline they will be kicked from the server.
 +
|- {{Added}}
 +
| Forced Message
 +
| [[Chat]]
 +
| This is sent with the force resourcepack popup.
 +
|}
 +
==== Title ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
!colspan="2"| Field Name
 +
! Field Type
 +
! Notes
 +
|- {{ Removed }}
 +
|rowspan="10"| 0x4F
 +
|rowspan="10"| Play
 +
|rowspan="10"| Client
 +
|colspan="2"| Action
 +
| VarInt Enum
 +
|
 +
|- {{ Removed }}
 +
! Action
 +
! Field Name
 +
!
 +
!
 +
|- {{ Removed }}
 +
| 0: set title
 +
| Title Text
 +
| [[Chat]]
 +
|
 +
|- {{ Removed }}
 +
| 1: set subtitle
 +
| Subtitle Text
 +
| [[Chat]]
 +
|
 +
|- {{ Removed }}
 +
| 2: set action bar
 +
| Action bar text
 +
| [[Chat]]
 +
| Displays a message above the hotbar (the same as position 2 in [[#Chat Message (clientbound)|Chat Message (clientbound)]].
 +
|- {{ Removed }}
 +
|rowspan="3"| 3: set times and display
 +
| Fade In
 +
| Int
 +
| Ticks to spend fading in.
 +
|- {{ Removed }}
 +
| Stay
 +
| Int
 +
| Ticks to keep the title displayed.
 +
|- {{ Removed }}
 +
| Fade Out
 +
| Int
 +
| Ticks to spend out, not when to start fading out.
 +
|- {{ Removed }}
 +
| 4: hide
 +
| ''no fields''
 +
| ''no fields''
 +
|  
 +
|- {{ Removed }}
 +
| 5: reset
 +
| ''no fields''
 +
| ''no fields''
 +
|
 +
|}
 +
 
 +
“Hide” makes the title disappear, but if you run times again the same title will appear. “Reset” erases the text.
 +
 
 +
The title is visible on screen for Fade In + Stay + Fade Out ticks.
 +
 
 +
==== Action Bar ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|- {{ Added }}
 +
|rowspan="4"| 0x40
 +
|rowspan="4"| Play
 +
|rowspan="4"| Client
 +
| Action bar text
 +
| [[Chat]]
 +
| Displays a message above the hotbar (the same as position 2 in [[#Chat Message (clientbound)|Chat Message (clientbound)]].
 +
|- {{ Added }}
 +
|}
 +
==== World Border Center ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|- {{ Added }}
 +
|rowspan="18"| 0x41
 +
|rowspan="18"| Play
 +
|rowspan="18"| Client
 +
| X
 +
| Double
 +
|
 +
|- {{ Added }}
 +
| Z
 +
| Double
 +
|
 +
|- {{ Added }}
 +
|}
 +
==== World Border Lerp Size ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|- {{ Added }}
 +
|rowspan="4"| 0x42
 +
|rowspan="4"| Play
 +
|rowspan="4"| Client
 +
| Old Diameter
 +
| Double
 +
| Current length of a single side of the world border, in meters.
 +
|- {{ Added }}
 +
| New Diameter
 +
| Double
 +
| Target length of a single side of the world border, in meters.
 +
|- {{ Added }}
 +
| Speed
 +
| VarLong
 +
| Number of real-time ''milli''seconds until New Diameter is reached. It appears that Notchian server does not sync world border speed to game ticks, so it gets out of sync with server lag. If the world border is not moving, this is set to 0.
 +
|-
 +
|}
 +
==== World Border Size ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|- {{ Added }}
 +
|rowspan="4"| 0x43
 +
|rowspan="4"| Play
 +
|rowspan="4"| Client
 +
| Diameter
 +
| Double
 +
| Length of a single side of the world border, in meters.
 +
|- {{ Added }}
 +
|}
 +
 
 +
==== World Border Warning Delay====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|- {{ Added }}
 +
|rowspan="4"| 0x44
 +
|rowspan="4"| Play
 +
|rowspan="4"| Client
 +
| Warning Time
 +
| VarInt
 +
| In seconds as set by <code>/worldborder warning time</code>.
 +
|- {{ Added }}
 +
|}
 +
 
 +
==== World Border Warning Reach====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|- {{ Added }}
 +
|rowspan="4"| 0x45
 +
|rowspan="4"| Play
 +
|rowspan="4"| Client
 +
| Warning Blocks
 +
| VarInt
 +
| In meters.
 +
|- {{ Added }}
 +
|}
 +
 
 +
==== Set Title SubTitle ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|- {{ Added }}
 +
|rowspan="4"| 0x56
 +
|rowspan="4"| Play
 +
|rowspan="4"| Client
 +
| Subtitle Text
 +
| [[Chat]]
 +
|- {{ Added }}
 +
|}
 +
 
 +
 
 +
==== Set Title Text ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|- {{ Added }}
 +
|rowspan="4"| 0x58
 +
|rowspan="4"| Play
 +
|rowspan="4"| Client
 +
| Title Text
 +
| [[Chat]]
 +
|- {{ Added }}
 +
|}
 +
 
 +
==== Set Title Time====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|- {{ Added }}
 +
|rowspan="4"| 0x59
 +
|rowspan="4"| Play
 +
|rowspan="4"| Client
 +
| Fade In
 +
| Int
 +
| Ticks to spend fading in.
 +
|- {{ Added }}
 +
| Stay
 +
| Int
 +
| Ticks to keep the title displayed.
 +
|- {{ Added }}
 +
| Fade Out
 +
| Int
 +
| Ticks to spend out, not when to start fading out.
 +
|}
 +
 
 +
 
 +
==== Tags ====
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
!colspan="2"| Field Name
 +
!colspan="2"| Field Type
 +
! Notes
 +
|-
 +
|rowspan="8"| {{change|0x5B|0x65}}
 +
|rowspan="8"| Play
 +
|rowspan="8"| Client
 +
|- {{removed}}
 +
| colspan="2"| Block Tags
 +
| colspan="2"| (See below)
 +
| IDs are block IDs
 +
|- {{removed}}
 +
| colspan="2"| Item Tags
 +
| colspan="2"| (See below)
 +
| IDs are item IDs
 +
|- {{removed}}
 +
| colspan="2"| Fluid Tags
 +
| colspan="2"| (See below)
 +
| IDs are fluid IDs
 +
|- {{removed}}
 +
| colspan="2"| Entity Tags
 +
| colspan="2"| (See below)
 +
| IDs are entity IDs
 +
|- {{added}}
 +
| colspan="2"| Length of the array
 +
| colspan="2"| VarInt
 +
|
 +
|- {{added}}
 +
|rowspan="2"| Array of tags
 +
| Tag type
 +
|rowspan="2"| Array
 +
| Identifier
 +
| Tag identifier (Vanilla required tags are <code>minecraft:block</code>, <code>minecraft:item</code>, <code>minecraft:fluid</code>, <code>minecraft:entity_type</code>, and <code>minecraft:game_event</code>)
 +
|-
 +
| Array of Tag
 +
| (See below)
 +
|
 +
|}
 +
 
 +
Tags look like:
 +
 
 +
{| class="wikitable"
 +
!colspan="2"| Field Name
 +
!colspan="2"| Field Type
 +
! Notes
 +
|-
 +
|colspan="2"| Length
 +
|colspan="2"| VarInt
 +
| Number of elements in the following array
 +
|-
 +
|rowspan="3"| Tags
 +
| Tag name
 +
|rowspan="3"| Array
 +
| Identifier
 +
|
 +
|-
 +
| Count
 +
| VarInt
 +
| Number of elements in the following array
 +
|-
 +
| Entries
 +
| Array of VarInt
 +
| Numeric ID of the given type (block, item, etc.).
 +
|}
 +
 
 +
 
 +
=== Serverbound ===
 +
 
 +
==== Client Settings ====
 +
 
 +
Sent when the player connects, or when settings are changed.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="7"| 0x05
 +
|rowspan="7"| Play
 +
|rowspan="7"| Server
 +
| Locale
 +
| String (16)
 +
| e.g. <code>en_GB</code>.
 +
|-
 +
| View Distance
 +
| Byte
 +
| Client-side render distance, in chunks.
 +
|-
 +
| Chat Mode
 +
| VarInt Enum
 +
| 0: enabled, 1: commands only, 2: hidden.  See [[Chat#Processing chat|processing chat]] for more information.
 +
|-
 +
| Chat Colors
 +
| Boolean
 +
| “Colors” multiplayer setting.
 +
|-
 +
| Displayed Skin Parts
 +
| Unsigned Byte
 +
| Bit mask, see below.
 +
|-
 +
| Main Hand
 +
| VarInt Enum
 +
| 0: Left, 1: Right.
 +
|- {{Added}}
 +
| Disable text filtering
 +
| Boolean
 +
| Disables filtering of text on signs and written book titles.  Currently always true (i.e. the filtering is disabled)
 +
|}
 +
 
 +
''Displayed Skin Parts'' flags:
 +
 
 +
* Bit 0 (0x01): Cape enabled
 +
* Bit 1 (0x02): Jacket enabled
 +
* Bit 2 (0x04): Left Sleeve enabled
 +
* Bit 3 (0x08): Right Sleeve enabled
 +
* Bit 4 (0x10): Left Pants Leg enabled
 +
* Bit 5 (0x20): Right Pants Leg enabled
 +
* Bit 6 (0x40): Hat enabled
 +
 
 +
The most significant bit (bit 7, 0x80) appears to be unused.
 +
 
 +
 
 +
==== Window Confirmation (serverbound) ====
 +
 
 +
If a confirmation sent by the client was not accepted, the server will reply with a [[#Window Confirmation (clientbound)|Window Confirmation (clientbound)]] packet with the Accepted field set to false. When this happens, the client must send this packet to apologize (as with movement), otherwise the server ignores any successive confirmations.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|- {{ Removed }}
 +
|rowspan="3"| 0x07
 +
|rowspan="3"| Play
 +
|rowspan="3"| Server
 +
| Window ID
 +
| Byte
 +
| The ID of the window that the action occurred in.
 +
|- {{ Removed }}
 +
| Action Number
 +
| Short
 +
| Every action that is to be accepted has a unique number. This number is an incrementing integer (starting at 1) with separate counts for each window ID.
 +
|- {{ Removed }}
 +
| Accepted
 +
| Boolean
 +
| Whether the action was accepted.
 +
|}
 +
== Handshaking ==
 +
 
 +
=== Clientbound ===
 +
 
 +
There are no clientbound packets in the Handshaking state, since the protocol immediately switches to a different state after the client sends the first packet.
 +
 
 +
=== Serverbound ===
 +
 
 +
==== Handshake ====
 +
 
 +
This causes the server to switch into the target state.
 +
 
 +
{| class="wikitable"
 +
! Packet ID
 +
! State
 +
! Bound To
 +
! Field Name
 +
! Field Type
 +
! Notes
 +
|-
 +
|rowspan="4"| 0x00
 +
|rowspan="4"| Handshaking
 +
|rowspan="4"| Server
 +
| Protocol Version
 +
| VarInt
 +
| See [[protocol version numbers]] (currently {{change|754|{{Snapshot PVN|1073741839}}}})
 +
|-
 +
| 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. Note that SRV records are a complete redirect, e.g. if _minecraft._tcp.example.com points to mc.example.org, users connecting to example.com will provide mc.example.org as server address in addition to connecting to it.
 +
|-
 +
| Server Port
 +
| Unsigned Short
 +
| Default is 25565.  The Notchian server does not use this information.
 +
|-
 +
| Next State
 +
| VarInt Enum
 +
| 1 for [[#Status|status]], 2 for [[#Login|login]]
 +
|}
 +
 
 +
== Status ==
 +
 
 +
=== Clientbound ===
 +
 
 +
No changes so far.
 +
 
 +
=== Serverbound ===
 +
 
 +
No changes so far.
 +
 
 +
== Login ==
  
== Removed Packets ==
+
=== Clientbound ===
  
-None-
+
No changes so far.
  
== Changed Data Types ==
+
=== Serverbound ===
  
-None-
+
No changes so far.
  
== Protocol History ==
 
  
-None-
+
[[Category:Minecraft Modern]]

Latest revision as of 02:28, 6 May 2021

This page documents the changes from the last stable Minecraft release (currently 1.16.5, protocol 754) to the current pre-release (currently 21w07a, protocol Snapshot 15). 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
Play clientbound
0x05 Sculk Vibration Signal Pre
0x05 0x06 Entity Animation (clientbound) Current (unchanged)
0x06 0x07 Statistics Current (unchanged)
0x07 0x08 Acknowledge Player Digging Current (unchanged)
0x08 0x09 Block Break Animation Current (unchanged)
0x09 0x0A Block Entity Data Current (unchanged)
0x0A 0x0B Block Action Current (unchanged)
0x0B 0x0C Block Change Current (unchanged)
0x0C 0x0D Boss Bar Current (unchanged)
0x0D 0x0E Server Difficulty Current (unchanged)
0x0E 0x0F Chat Message (clientbound) Current (unchanged)
0x10 Clear Titles Pre
0x0F 0x11 Tab-Complete (clientbound) Current (unchanged)
0x10 0x12 Declare Commands Current (unchanged)
0x11 Window Confirmation (clientbound) Current
0x12 0x13 Close Window (clientbound) Current (unchanged)
0x13 0x14 Window Items Current (unchanged)
0x14 0x15 Window Property Current (unchanged)
0x15 0x16 Set Slot Current (unchanged)
0x16 0x17 Set Cooldown Current (unchanged)
0x17 0x18 Plugin Message (clientbound) Current (unchanged)
0x18 0x19 Named Sound Effect Current (unchanged)
0x19 0x1A Disconnect (play) Current (unchanged)
0x1A 0x1B Entity Status Current (unchanged)
0x1B 0x1C Explosion Current (unchanged)
0x1C 0x1D Unload Chunk Current (unchanged)
0x1D 0x1E Change Game State Current (unchanged)
0x1E 0x1F Open Horse Window Current (unchanged)
0x20 Initialize World Border Pre
0x1F 0x21 Keep Alive (clientbound) Current (unchanged)
0x20 0x22 Chunk Data Current Pre
0x21 0x23 Effect Current (unchanged)
0x22 0x24 Particle Current (unchanged)
0x23 0x25 Update Light Current Pre
0x24 0x26 Join Game Current (unchanged)
0x25 0x27 Map Data Current Pre
0x26 0x28 Trade List Current (unchanged)
0x27 0x29 Entity Position Current (unchanged)
0x28 0x2A Entity Position and Rotation Current (unchanged)
0x29 0x2B Entity Rotation Current (unchanged)
0x2A Entity Movement Current
0x2B 0x2C Vehicle Move (clientbound) Current (unchanged)
0x2C 0x2D Open Book Current (unchanged)
0x2D 0x2E Open Window Current (unchanged)
0x2E 0x2F Open Sign Editor Current (unchanged)
0x2F 0x30 Craft Recipe Response Current (unchanged)
0x30 0x31 Player Abilities (clientbound) Current (unchanged)
0x31 Combat Event Current
0x32 End Combat Event Pre
0x33 Enter Combat Event Pre
0x34 Death Combat Event Pre
0x32 0x35 Player Info Current (unchanged)
0x33 0x36 Face Player Current (unchanged)
0x36 Destroy Entities Current Pre|rel=removed}}
0x34 0x37 Player Position And Look (clientbound) Current Pre
0x35 0x38 Unlock Recipes Current (unchanged)
0x39 Destroy Entity Current Pre|rel=added}}
0x37 0x3A Remove Entity Effect Current (unchanged)
0x38 0x3B Resource Pack Send Current Pre
0x39 0x3C Respawn Current (unchanged)
0x3A 0x3D Entity Head Look Current (unchanged)
0x3B 0x3E Multi Block Change Current (unchanged)
0x3C 0x3F Select Advancement Tab Current (unchanged)
0x40 Action Bar Pre
0x41 World Border Center Pre
0x42 World Border Lerp Size Pre
0x43 World Border Size Pre
0x44 World Border Warning Delay Pre
0x45 World Border Warning Reach Pre
0x3E 0x46 Camera Current (unchanged)
0x3F 0x47 Held Item Change (clientbound) Current (unchanged)
0x40 0x48 Update View Position Current (unchanged)
0x41 0x49 Update View Distance Current (unchanged)
0x42 0x4A Spawn Position Current (unchanged)
0x43 0x4B Display Scoreboard Current (unchanged)
0x44 0x4C Entity Metadata Current (unchanged)
0x45 0x4D Attach Entity Current (unchanged)
0x46 0x4E Entity Velocity Current (unchanged)
0x47 0x4F Entity Equipment Current (unchanged)
0x4F Title Current Pre
0x48 0x50 Set Experience Current (unchanged)
0x49 0x51 Update Health Current (unchanged)
0x4A 0x52 Scoreboard Objective Current (unchanged)
0x4B 0x53 Set Passengers Current (unchanged)
0x4C 0x54 Teams Current (unchanged)
0x4D 0x55 Update Score Current (unchanged)
0x56 Set Title SubTitle Pre
0x57 Time Update Current (unchanged)
0x58 Set Title Text Pre
0x59 Set Title Time Pre
0x50 0x5A Entity Sound Effect Current (unchanged)
0x51 0x5B Sound Effect Current (unchanged)
0x52 0x5C Stop Sound Current (unchanged)
0x53 0x5D Player List Header And Footer Current (unchanged)
0x54 0x5E NBT Query Response Current (unchanged)
0x55 0x5F Collect Item Current (unchanged)
0x56 0x60 Entity Teleport Current (unchanged)
0x57 0x61 Advancements Current (unchanged)
0x58 0x62 Entity Properties Current (unchanged)
0x59 0x63 Entity Effect Current (unchanged)
0x5A 0x64 Declare Recipes Current (unchanged)
0x5B 0x65 Tags Current Pre
Play serverbound
0x05 Client Settings Current Pre
Handshaking serverbound
0x00 Handshake Current Pre

New/modified data types

No changes so far.

Entity Metadata

Warning.png Note that other entities have had metadata shifts due to these changes, not shown here.

Entity

The base class.

Index Type Meaning Default
0 Byte Bit mask Meaning 0
0x01 Is on fire
0x02 Is crouching
0x04 Unused (previously riding)
0x08 Is sprinting
0x10 Is swimming
0x20 Is invisible
0x40 has glowing effect
0x80 Is flying with an elytra
1 VarInt Air ticks 300
2 OptChat Custom name empty
3 Boolean Is custom name visible false
4 Boolean Is silent false
5 Boolean Has no gravity false
6 Pose Pose STANDING
7 VarInt Ticks frozen in powdered snow 0

Block Actions

No changes so far.

Inventories

No changes so far.

Plugin Channels

No changes so far.

Play

Clientbound

Sculk Vibration Signal

Packet ID State Bound To Field Name Field Type Notes
0x05 Play Client Source Position Position Source position for the vibration.
Destination Identifier Identifier Identifier of the destination codec type.
Destination Varies Vanilla default destinations are a block position encoded as a Position for "block" or an entity id encoded as a VarInt for "entity".
Arrival Ticks VarInt Ticks for the signal to arrive at the destination.

This packet shows a permanent particle.

Clear Titles

Packet ID State Bound To Field Name Field Type Notes
0x10 Play Client
Reset Boolean

Initialize World Border

Packet ID State Bound To Field Name Field Type Notes
0x20 Play Client X Double
Z Double
Old Diameter Double Current length of a single side of the world border, in meters.
New Diameter Double Target length of a single side of the world border, in meters.
Speed VarLong Number of real-time milliseconds until New Diameter is reached. It appears that Notchian server does not sync world border speed to game ticks, so it gets out of sync with server lag. If the world border is not moving, this is set to 0.
Portal Teleport Boundary VarInt Resulting coordinates from a portal teleport are limited to ±value. Usually 29999984.
Warning Blocks VarInt In meters.
Warning Time VarInt In seconds as set by /worldborder warning time.

The Notchian client determines how solid to display the warning by comparing to whichever is higher, the warning distance or whichever is lower, the distance from the current diameter to the target diameter or the place the border will be after warningTime seconds. In pseudocode:

distance = max(min(resizeSpeed * 1000 * warningTime, abs(targetDiameter - currentDiameter)), warningDistance);
if (playerDistance < distance) {
    warning = 1.0 - playerDistance / distance;
} else {
    warning = 0.0;
}

Chunk Data

Main article: Chunk Format
See also: #Unload Chunk
Huh.png The following information needs to be added to this page:
How do biomes work now? The biome change happened at the same time as the seed change, but it's not clear how/if biomes could be computed given that it's not the actual seed... (/r/mojira discussion which notes that it seems to be some kind of interpolation, and 3D biomes are only used in the nether)

The server only sends skylight information for chunk pillars in the Overworld, it's up to the client to know in which dimension the player is currently located. You can also infer this information from the primary bitmask and the amount of uncompressed bytes sent. This packet also sends all block entities in the chunk (though sending them is not required; it is still legal to send them with Update Block Entity later).

Packet ID State Bound To Field Name Field Type Notes
0x20 0x22 Play Client Chunk X Int Chunk coordinate (block coordinate divided by 16, rounded down)
Chunk Z Int Chunk coordinate (block coordinate divided by 16, rounded down)
Full chunk Boolean See Chunk Format
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).
Bit Mask Length VarInt Length of the following array
Primary Bit Mask Array of Long BitSet with bits (world height in blocks / 16) 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 the lowest y to 15 blocks above).
Heightmaps NBT Compound containing one long array named MOTION_BLOCKING, which is a heightmap for the highest solid block at each position in the chunk (as a compacted long array with 256 entries at 9 bits per entry totaling 36 longs). The Notchian server also adds a WORLD_SURFACE long array, the purpose of which is unknown, but it's not required for the chunk to be accepted.
Biomes length Optional VarInt Size of the following array; should always be 1024. Not present if full chunk is false.
Biomes Optional Array of VarInt 1024 biome IDs, ordered by x then z then y, in 4×4×4 blocks. Not present if full chunk is false. See Chunk Format § Biomes.
Size VarInt Size of Data in bytes
Data Byte array See data structure in Chunk Format
Number of block entities VarInt Number of elements in the following array
Block entities Array of NBT Tag All block entities in the chunk. Use the x, y, and z tags in the NBT to determine their positions.

Note that the Notchian client requires an Update View Position packet when it crosses a chunk border, otherwise it'll only display render distance + 2 chunks around the chunk it spawned in.

The compacted array format has been adjusted so that individual entries no longer span across multiple longs, affecting the main data array and heightmaps.

New format, 5 bits per block, containing the following references to blocks in a palette (not shown): 122344566480743131516914101202

0020863148418841 0000000000100000100001100011000101001000010000011000100001000001
01018A7260F68C87 0000000100000001100010100111001001100000111101101000110010000111

Entity Movement

This packet may be used to initialize an entity.

For player entities, either this packet or any move/look packet is sent every game tick. So the meaning of this packet is basically that the entity did not move/look since the last such packet.

Packet ID State Bound To Field Name Field Type Notes
0x2A Play Client Entity ID VarInt

Update Light

Updates light levels for a chunk.

Packet ID State Bound To Field Name Field Type Notes
0x23 0x25 Play Client Chunk X VarInt Chunk coordinate (block coordinate divided by 16, rounded down)
Chunk Z VarInt Chunk coordinate (block coordinate divided by 16, rounded down)
Trust Edges Boolean If edges should be trusted for light updates.
Sky Light Mask VarInt Mask containing 18 bits, with the lowest bit corresponding to chunk section -1 (in the void, y=-16 to y=-1) and the highest bit for chunk section 16 (above the world, y=256 to y=271)
Block Light Mask VarInt Mask containing 18 bits, with the same order as sky light
Empty Sky Light Mask VarInt Mask containing 18 bits, which indicates sections that have 0 for all their sky light values. If a section is set in both this mask and the main sky light mask, it is ignored for this mask and it is included in the sky light arrays (the notchian server does not create such masks). If it is only set in this mask, it is not included in the sky light arrays.
Empty Block Light Mask VarInt Mask containing 18 bits, which indicates sections that have 0 for all their block light values. If a section is set in both this mask and the main block light mask, it is ignored for this mask and it is included in the block light arrays (the notchian server does not create such masks). If it is only set in this mask, it is not included in the block light arrays.
Length 1 VarInt Length of the following array
Sky Light Mask Array of Long BitSet containing bits for each sections in the world + 2 (lowest bit 16-1 blocks below min world height, highest 1-16 above max world height)
Length 2 VarInt Length of the following array
Block Light Mask Array of Long BitSet containing bits for each sections in the world + 2, same order as sky light
Length 3 VarInt Length of the following array
Empty Sky Light Mask Array of Long BitSet containing a variable amount of bits (see sky/block light) which indicates sections that have 0 for all their sky light values
Length 4 VarInt Length of the following array
Empty Block Light Mask Array of Long BitSet containing a variable amount of bits (see sky/block light) which indicates sections that have 0 for all their block light values
Sky Light array count VarInt Number of entries in the following array
Sky Light arrays Length Array VarInt Length of the following array in bytes (always 2048)
Sky Light array Array of 2048 bytes There is 1 array for each bit set to true in the sky light mask, starting with the lowest value. Half a byte per light value.
Block Light array count VarInt Number of entries in the following array
Block Light arrays Length Array VarInt Length of the following array in bytes (always 2048)
Block Light array Array of 2048 bytes There is 1 array for each bit set to true in the block light mask, starting with the lowest value. Half a byte per light value.


Map Data

Updates a rectangular area on a map item.

Packet ID State Bound To Field Name Field Type Notes
0x25 0x27 Play Client Map ID VarInt Map ID of the map being modified
Scale Byte From 0 for a fully zoomed-in map (1 block per pixel) to 4 for a fully zoomed-out map (16 blocks per pixel)
Tracking Position Boolean Specifies whether player and item frame icons are shown
Locked Boolean True if the map has been locked in a cartography table
Tracking Position Boolean Specifies whether player and item frame icons are shown
Icon Count VarInt Number of elements in the following array. Only present if "Tracking Position" is true.
Icon Type Array VarInt enum See below
X Byte Map coordinates: -128 for furthest left, +127 for furthest right
Z Byte Map coordinates: -128 for highest, +127 for lowest
Direction Byte 0-15
Has Display Name Boolean
Display Name Optional Chat Only present if previous Boolean is true
Columns Unsigned Byte Number of columns updated
Rows Optional Byte Only if Columns is more than 0; number of rows updated
X Optional Byte Only if Columns is more than 0; x offset of the westernmost column
Z Optional Byte Only if Columns is more than 0; z offset of the northernmost row
Length Optional VarInt Only if Columns is more than 0; length of the following array
Data Optional Array of Unsigned Byte Only if Columns is more than 0; see Map item format

For icons, a direction of 0 is a vertical icon and increments by 22.5° (360/16).

Types are based off of rows and columns in map_icons.png:

Icon type Result
0 White arrow (players)
1 Green arrow (item frames)
2 Red arrow
3 Blue arrow
4 White cross
5 Red pointer
6 White circle (off-map players)
7 Small white circle (far-off-map players)
8 Mansion
9 Temple
10 White Banner
11 Orange Banner
12 Magenta Banner
13 Light Blue Banner
14 Yellow Banner
15 Lime Banner
16 Pink Banner
17 Gray Banner
18 Light Gray Banner
19 Cyan Banner
20 Purple Banner
21 Blue Banner
22 Brown Banner
23 Green Banner
24 Red Banner
25 Black Banner
26 Treasure marker

Combat Event

Originally used for metadata for twitch streaming circa 1.8. Now only used to display the game over screen (with enter combat and end combat completely ignored by the Notchain client)

Packet ID State Bound To Field Name Field Type Notes
0x31 Play Client Event VarInt Enum Determines the layout of the remaining packet.
Event Field Name
0: enter combat no fields no fields
1: end combat Duration VarInt Length of the combat in ticks.
Entity ID Int ID of the primary opponent of the ended combat, or -1 if there is no obvious primary opponent.
2: entity dead Player ID VarInt Entity ID of the player that died (should match the client's entity ID).
Entity ID Int The killing entity's ID, or -1 if there is no obvious killer.
Message Chat The death message.

End Combat Event

Unused by the Notchain client.

Packet ID State Bound To Field Name Field Type Notes
0x32 Play Client Duration VarInt Length of the combat in ticks.
Entity ID Int ID of the primary opponent of the ended combat, or -1 if there is no obvious primary opponent.

Enter Combat Event

Unused by the Notchain client.

Packet ID State Bound To Field Name Field Type Notes
0x33 Play Client


Death Combat Event

Used to send a respawn screen.

Packet ID State Bound To Field Name Field Type Notes
0x34 Play Client Player ID VarInt Entity ID of the player that died (should match the client's entity ID).
Entity ID Int The killing entity's ID, or -1 if there is no obvious killer.
Message Chat The death message.

Player Position And Look (clientbound)

Updates the player's position on the server. This packet will also close the “Downloading Terrain” screen when joining/respawning.

If the distance between the last known position of the player on the server and the new position set by this packet is greater than 100 meters, the client will be kicked for “You moved too quickly :( (Hacking?)”.

Also if the fixed-point number of X or Z is set greater than 3.2E7D the client will be kicked for “Illegal position”.

Yaw is measured in degrees, and does not follow classical trigonometry rules. The unit circle of yaw on the XZ-plane starts at (0, 1) and turns counterclockwise, with 90 at (-1, 0), 180 at (0, -1) and 270 at (1, 0). Additionally, yaw is not clamped to between 0 and 360 degrees; any number is valid, including negative numbers and numbers greater than 360.

Pitch is measured in degrees, where 0 is looking straight ahead, -90 is looking straight up, and 90 is looking straight down.

Packet ID State Bound To Field Name Field Type Notes
0x34 0x38 Play Client X Double Absolute or relative position, depending on Flags.
Y Double Absolute or relative position, depending on Flags.
Z Double Absolute or relative position, depending on Flags.
Yaw Float Absolute or relative rotation on the X axis, in degrees.
Pitch Float Absolute or relative rotation on the Y axis, in degrees.
Flags Byte Bit field, see below.
Teleport ID VarInt Client should confirm this packet with Teleport Confirm containing the same Teleport ID.
Dismount Vehicle Boolean True if the player should dismount their vehicle.

About the Flags field:

<Dinnerbone> It's a bitfield, X/Y/Z/Y_ROT/X_ROT. If X is set, the x value is relative and not absolute.
Field Bit
X 0x01
Y 0x02
Z 0x04
Y_ROT 0x08
X_ROT 0x10

Destroy Entity

Sent by the server when a list of entities an entity is to be destroyed on the client.

Packet ID State Bound To Field Name Field Type Notes
0x36 Play Client
Count VarInt Number of elements in the following array.
Array of VarInt The list of entities of destroy.
Entity ID VarInt

Resource Pack Send

Packet ID State Bound To Field Name Field Type Notes
0x38 0x3B Play Client URL String (32767) The URL to the resource pack.
Hash String (40) A 40 character hexadecimal and lowercase SHA-1 hash of the resource pack file. (must be lower case in order to work)
If it's not a 40 character hexadecimal string, the client will not use it for hash verification and likely waste bandwidth — but it will still treat it as a unique id
Forced Boolean The notchian client will be forced to use the resource pack from the server. If they decline they will be kicked from the server.
Forced Message Chat This is sent with the force resourcepack popup.

Title

Packet ID State Bound To Field Name Field Type Notes
0x4F Play Client Action VarInt Enum
Action Field Name
0: set title Title Text Chat
1: set subtitle Subtitle Text Chat
2: set action bar Action bar text Chat Displays a message above the hotbar (the same as position 2 in Chat Message (clientbound).
3: set times and display Fade In Int Ticks to spend fading in.
Stay Int Ticks to keep the title displayed.
Fade Out Int Ticks to spend out, not when to start fading out.
4: hide no fields no fields
5: reset no fields no fields

“Hide” makes the title disappear, but if you run times again the same title will appear. “Reset” erases the text.

The title is visible on screen for Fade In + Stay + Fade Out ticks.

Action Bar

Packet ID State Bound To Field Name Field Type Notes
0x40 Play Client Action bar text Chat Displays a message above the hotbar (the same as position 2 in Chat Message (clientbound).

World Border Center

Packet ID State Bound To Field Name Field Type Notes
0x41 Play Client X Double
Z Double

World Border Lerp Size

Packet ID State Bound To Field Name Field Type Notes
0x42 Play Client Old Diameter Double Current length of a single side of the world border, in meters.
New Diameter Double Target length of a single side of the world border, in meters.
Speed VarLong Number of real-time milliseconds until New Diameter is reached. It appears that Notchian server does not sync world border speed to game ticks, so it gets out of sync with server lag. If the world border is not moving, this is set to 0.

World Border Size

Packet ID State Bound To Field Name Field Type Notes
0x43 Play Client Diameter Double Length of a single side of the world border, in meters.

World Border Warning Delay

Packet ID State Bound To Field Name Field Type Notes
0x44 Play Client Warning Time VarInt In seconds as set by /worldborder warning time.

World Border Warning Reach

Packet ID State Bound To Field Name Field Type Notes
0x45 Play Client Warning Blocks VarInt In meters.

Set Title SubTitle

Packet ID State Bound To Field Name Field Type Notes
0x56 Play Client Subtitle Text Chat


Set Title Text

Packet ID State Bound To Field Name Field Type Notes
0x58 Play Client Title Text Chat

Set Title Time

Packet ID State Bound To Field Name Field Type Notes
0x59 Play Client Fade In Int Ticks to spend fading in.
Stay Int Ticks to keep the title displayed.
Fade Out Int Ticks to spend out, not when to start fading out.


Tags

Packet ID State Bound To Field Name Field Type Notes
0x5B 0x65 Play Client
Block Tags (See below) IDs are block IDs
Item Tags (See below) IDs are item IDs
Fluid Tags (See below) IDs are fluid IDs
Entity Tags (See below) IDs are entity IDs
Length of the array VarInt
Array of tags Tag type Array Identifier Tag identifier (Vanilla required tags are minecraft:block, minecraft:item, minecraft:fluid, minecraft:entity_type, and minecraft:game_event)
Array of Tag (See below)

Tags look like:

Field Name Field Type Notes
Length VarInt Number of elements in the following array
Tags Tag name Array Identifier
Count VarInt Number of elements in the following array
Entries Array of VarInt Numeric ID of the given type (block, item, etc.).


Serverbound

Client Settings

Sent when the player connects, or when settings are changed.

Packet ID State Bound To Field Name Field Type Notes
0x05 Play Server Locale String (16) e.g. en_GB.
View Distance Byte Client-side render distance, in chunks.
Chat Mode VarInt Enum 0: enabled, 1: commands only, 2: hidden. See processing chat for more information.
Chat Colors Boolean “Colors” multiplayer setting.
Displayed Skin Parts Unsigned Byte Bit mask, see below.
Main Hand VarInt Enum 0: Left, 1: Right.
Disable text filtering Boolean Disables filtering of text on signs and written book titles. Currently always true (i.e. the filtering is disabled)

Displayed Skin Parts flags:

  • Bit 0 (0x01): Cape enabled
  • Bit 1 (0x02): Jacket enabled
  • Bit 2 (0x04): Left Sleeve enabled
  • Bit 3 (0x08): Right Sleeve enabled
  • Bit 4 (0x10): Left Pants Leg enabled
  • Bit 5 (0x20): Right Pants Leg enabled
  • Bit 6 (0x40): Hat enabled

The most significant bit (bit 7, 0x80) appears to be unused.


Window Confirmation (serverbound)

If a confirmation sent by the client was not accepted, the server will reply with a Window Confirmation (clientbound) packet with the Accepted field set to false. When this happens, the client must send this packet to apologize (as with movement), otherwise the server ignores any successive confirmations.

Packet ID State Bound To Field Name Field Type Notes
0x07 Play Server Window ID Byte The ID of the window that the action occurred in.
Action Number Short Every action that is to be accepted has a unique number. This number is an incrementing integer (starting at 1) with separate counts for each window ID.
Accepted Boolean Whether the action was accepted.

Handshaking

Clientbound

There are no clientbound packets in the Handshaking state, since the protocol immediately switches to a different state after the client sends the first packet.

Serverbound

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 754 Snapshot 15)
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. Note that SRV records are a complete redirect, e.g. if _minecraft._tcp.example.com points to mc.example.org, users connecting to example.com will provide mc.example.org as server address in addition to connecting to it.
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

Status

Clientbound

No changes so far.

Serverbound

No changes so far.

Login

Clientbound

No changes so far.

Serverbound

No changes so far.