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Minecraft Beta multiplayer server

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C(o o)O     C H U N K Y   M O N K E Y
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 w====m==|       minecraft server

Chunky Monkey is a Minecraft Beta multiplayer server. It is licensed under the MIT open source license, please see the LICENSE file for more information.

Website: Mailing list: Contact: John Beisley


Chunky Monkey is currently in early development and does not yet run anything that could be considered a full game experience.

Worlds generated by Alpha or Beta Notchian clients or servers can be loaded by the server.

Features include:

  • Compatibility with Minecraft Beta clients.
  • Blocks may be dug, items picked up, and blocks placed.
  • Crafting using the 2x2 or 3x3 crafting grids and the furnace.
  • Partial item physics.
  • World persistency.
  • Basic world generation.

Currently missing features include:

  • Block physics.
  • Complete item physics (there is a minimal implementation in place).
  • Mob behaviour.
  • Many block interactions.
  • Decent world generation.


Chunky Monkey is looking for assistance in furthering its development.

Key skills:

  • Use of Git and Github.
  • Moderate skill in the Go programming language.
  • Ability to write clear, maintainable code.
  • Unit testing knowledge.
  • Understanding of goroutine concurrency primitives.

Highly desireable skills:

  • Embedding a scripting environment (perhaps Lua?) into Go.
  • Low-latency reliable network communication.
  • Server scalabilty and reliability architecture.
  • Service monitoring.
  • World generation (including noise generation).

If you're interested in working on the project - it's best to contact Huin via Github, or on the Freenode IRC network in the #mcdevs channel.


The Go toolchain must be installed. Note that chunkymonkey is developed against the current stable release of the Go toolchain, so might not compile against the weekly releases (gofix might be able to fix such cases).

Building & Testing

Godag is used to build chunkymonkey. Install it, and run:

$ make

If you are developing, you are encouraged to run the unit tests with:

$ make test

The unit tests require GoMock to be installed.


Serve up a single player world:

$ bin/chunkymonkey ~/.minecraft/saves/World1
2010/10/03 16:32:13 Listening on  :25565


For debugging it is often useful to record a player's actions and replay them one or more times later. This makes it possible to simulate multiplayer games without having real people logging in.

To record a session, run the intercept proxy:

$ bin/intercept -record player.log localhost:25567 localhost:25565

Which will accept client connections on localhost port 25567 and relay the connection to the server at localhost port 25565. This has the side effect of display packets that pass through to stderr.

Connect your Minecraft client to localhost:25567, and a record of the clients actions will be stored to player.log-1, player.log-2 etc. (one file per client connection).

To replay a session:

$ bin/replay localhost:25565 player.log-1
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