UltraCompress
A near-lossless 5-bit transformer compression method with verifiable, reproducible reconstruction: a CLI generates text against a hosted compressed model, browses a model catalog, and verifies a downloaded pack's integrity against a published SHA-256 manifest.
UltraCompress compresses a transformer model from fp16 or bf16 down to a 5-bit pack while keeping quality close to the original - the authors report a 1.0066x perplexity ratio against a streaming bf16 teacher for a 405-billion-parameter model, measured on a held-out FineWeb-Edu tail. The central claim is reproducibility: an auditor can re-derive the validated quantized artifact from the pack and verify it byte-for-byte against a published SHA-256 manifest, aimed at regulated deployments in healthcare, defense, legal and quantitative-finance settings where matching a validated artifact matters.
The public package is intentionally minimal and contains no compression or reconstruction code, since that method is patent-pending; it provides a CLI to generate text against a Sipsa-hosted compressed model, browse the model catalog with quality-ratio tiers, and verify a downloaded pack's structure and download integrity. Full reproducible reconstruction of a pack is performed by Sipsa Labs under a paid engagement rather than by the open package itself.
It installs through pip and can run a first generation with no GPU and no signup.