Crate valence

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❗ NOTE: This documentation is sourced from the main branch. If you’re looking for the most recent stable release, go here.

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Note: Valence is currently undergoing a major rewrite. See #620 for details.

A Rust framework for building Minecraft: Java Edition servers.

Built on top of Bevy ECS, Valence is an effort to create a Minecraft compatible server completely from scratch in Rust. You can think of Valence as a game engine for Minecraft servers. It doesn’t do much by default, but by writing game logic yourself and leveraging Bevy’s powerful plugin system, you can make almost anything.

Opinionated features like dynamic scripting, dedicated executables, and vanilla game mechanics are all expected to be built as optional plugins. This level of modularity is desirable for those looking to build highly custom experiences in Minecraft such as minigame servers.

⚠️ Valence is still early in development with many features unimplemented or incomplete. Expect to encounter bugs, limitations, and breaking changes.


Valence aims to be the following:

  • Complete. Abstractions for the full breadth of the Minecraft protocol.
  • Flexible. Can easily extend Valence from within user code. Direct access to the Minecraft protocol is provided.
  • Modular. Pick and choose the components you need.
  • Intuitive. An API that is easy to use and difficult to misuse. Extensive documentation and examples are important.
  • Efficient. Optimal use of system resources with multiple CPU cores in mind. Valence uses very little memory and can support thousands of players at the same time without lag (assuming you have the bandwidth).
  • Up to date. Targets the most recent stable version of Minecraft. Support for multiple versions at once is not planned. However, you can use a proxy with ViaBackwards to achieve backwards compatibility with older clients.

§Current Status

Here are some noteworthy achievements:

  • valence_nbt: A speedy new library for Minecraft’s Named Binary Tag (NBT) format.
  • Authentication, encryption, and compression
  • Block states
  • Chunks
  • Entities and metadata
  • Bounding volume hierarchy for fast spatial entity queries
  • Player list and player skins
  • Dimensions, biomes, and worlds
  • JSON Text API
  • A Fabric mod for extracting data from the game into JSON files. These files are processed by a build script to generate Rust code for the project. The JSON files can be used in other projects as well.
  • Inventories
  • Items
  • Particles
  • Anvil file format (read only)
  • Proxy support (Velocity, Bungeecord and Waterfall)

Here is a short video showing the examples and some of Valence’s capabilities.

§Getting Started

§Running the Examples

After cloning the repository, run this command to try an example.

cargo r -r --example parkour

I also recommend giving game_of_life, terrain, and cow_sphere a try.

Next, open your Minecraft client and connect to the address localhost. If all goes well you should be playing on the server.

§Adding Valence as a Dependency

Valence is published to Run cargo add valence to add it to your project.

However, the version is likely outdated. To use the most recent development version, add Valence as a git dependency.

valence = { git = "" }

Documentation from the main branch is available here.


Contributions are welcome! Please see You can join Discord or GitHub Discussions to discuss the project and ask questions.


Code is licensed under MIT while the Valence logo is under CC BY-NC-ND 4.0


If you would like to contribute financially, consider sponsoring me (rj00a) on GitHub or Patreon.

I would love to continue working on Valence and your support would help me do that. Thanks!




  • Creates a new Ident at compile time from a string literal. A compile error is raised if the string is not a valid resource identifier.




  • Minecraft’s standard ticks per second (TPS).
  • The stringified name of the Minecraft version this library currently targets.
  • The Minecraft protocol version this library currently targets.