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A python tool for validating anvil/region files from Minecraft.
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AnvilChecker is a python script which is able to validate files in the Region file format. This script attempts to validate all points of possible breakage within these files. The script was made to help diagnose a flakey Region file engine.


AnvilChecker can be run using the following command:

./ <name of file or directory>

If passed a directory, AnvilChecker will assume it is the region directory and check all region files contained. If no directory or file is passed, AnvilChecker will work in the current directory.

Checks AnvilChecker runs

  • Region file is of proper length
  • Chunks in the region file don't accidentally write off the end of the file according to the offset buffer
  • Chunks in the region file don't accidentally write over each other according to the offset buffer
  • Length reported inside the chunk is actually the correct length given the amount of sectors it was allocated
  • Compression reported by the chunk is valid
    • Warning thrown when using GZip, since no one actually ever uses it since its stupid
  • Attempts to find chunks which were not allocated but still in the file using the compression flag as a heuristic
  • Displays a usage of the sector


AnvilChecker is licensed under the MIT License. This license can be viewed in LICENSE

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