From the spec page:

Overall Description

LGX is a deterministic package format for distributing multi-platform artifacts. It provides a standardized way to bundle platform-specific binaries, libraries, or other files into a single distributable archive with strong guarantees about reproducibility and integrity.

The format is designed to:

  • Support multiple platform variants (e.g., linux-amd64, darwin-arm64) in a single package
  • Produce byte-identical archives given identical inputs (deterministic)
  • Ensure cross-platform path compatibility through Unicode NFC normalization (macOS often uses decomposed forms; Linux commonly uses composed - NFC avoids “same name, different bytes” breaking lookups, hashing, and determinism)
  • Enforce a strict, predictable internal structure
  • Provide tooling for creating, modifying, and validating packages

Definitions & Acronyms

TermDefinition
LGXLogos Package Format - the package format specified in this document
VariantA platform-specific or configuration-specific build of the package contents (e.g., linux-amd64)
NFCUnicode Normalization Form C - a Unicode normalization form that uses canonical decomposition followed by canonical composition
USTARUnix Standard TAR - a standardized tar archive format
ManifestThe manifest.json file containing package metadata
MainThe entry point file for each variant, specified in the manifest
COSECBOR Object Signing and Encryption - reserved for future signature support