Libre Minecraft mappings, free to use for everyone. No exceptions.
Branch: 19w07a
Clone or download


Yarn is a set of open, unencumbered Minecraft mappings, free for everyone to use under the Creative Commons Zero license. The intention is to let everyone mod Minecraft freely and openly, while also being able to innovate and process the mappings as they see fit.

To see the current version being targetted, check the branch name!


Please remember that copying and pasting mappings from alternate projects under more restrictive licenses (such as MCP) is completely forbidden without explicit permission from the owners of said mappings. Discussing the naming approaches used in said projects is also not welcome - you have been warned. However, it is a good idea to consult name changes with other people - use pull requests or our community spaces to ask questions!

Getting Started

  1. Fork and clone the repo
  2. Run ./gradlew yarn (Linux, macOS) or gradlew yarn (Windows)
  3. Profit


Yarn uses Gradle to provide a number of utility tasks for working with the mappings.


Downloads the client and server Minecraft jars for the current Minecraft version to .gradle/minecraft


Merges the client and server jars into one merged jar, located at VERSION-merged.jar in the mappings directory where VERSION is the current Minecraft version.


download and mergeJars


setupYarn and download and launch the latest version of Enigma automatically configured to use the merged jar and the mappings.