openvm-zorch

A lean OpenVM prover built on zorch's scheme-agnostic SNARK blocks.

FRX → zorch (scheme-/zkVM-agnostic blocks) → openvm-zorch (SWIRL glue)

FRX is Fractalyze's fork of JAX, and it compiles through Fractalyze's fork of XLA. Both differ from upstream in the way that matters here: finite fields are native dtypes, not emulated. Everywhere below, FRX and XLA mean those forks.

OpenVM proves with SWIRL — a sumcheck-based proof system composing LogUp-GKR (interactions), a batched ZeroCheck with univariate skip (constraints), a stacked opening reduction, and a WHIR polynomial commitment — as implemented by openvm-stark-backend at tag v2.0.0. This repo re-implements that prover on zorch, keeping only the SWIRL-specific surface here and pushing every generic block upstream.

Installation

Python 3.11 on Linux x86_64 only.

CPU

pip install openvm-zorch

GPU (CUDA 12)

pip install openvm-zorch 'frx[cuda12]' \
    --extra-index-url https://fractalyze.github.io/pypi/simple/

The extra index carries the CUDA plugin wheels, which are too large for PyPI's per-file limit. It is not needed for the CPU tier.

Verify

python -c "import frx, openvm_zorch; print(frx.devices()); print(openvm_zorch.__version__)"

[CpuDevice(id=0)] means the CPU tier; a CUDA install prints the GPU devices.

Development

bazel test //...                              # hermetic, CPU by default

Regenerate golden fixtures (requires Rust toolchain; pinned to the reference tag, so output is reproducible):

cd tools/fixture-gen
cargo run --release -- \
  --out ../../openvm_zorch/commit/testdata/stacked_commit \
  --transcript-out ../../openvm_zorch/testdata/transcript \
  --gkr-out ../../openvm_zorch/logup_gkr/testdata/logup_gkr \
  --zerocheck-out ../../openvm_zorch/logup_zerocheck/testdata/zerocheck \
  --stacking-out ../../openvm_zorch/stacked_reduction/testdata/stacking \
  --whir-out ../../openvm_zorch/whir/testdata/whir \
  --prove-out ../../openvm_zorch/testdata/prove

Reference pin

openvm-stark-backend tag v2.0.0 (16d60de724c21dcadfde7d8315a1db507e5832d7) — the same pin the openvm v2.0.0 release consumes. Config: BabyBear base field, BabyBear⁴ challenges, Poseidon2 width-16 (default_babybear_poseidon2_16, plonky3 =0.4.3).

Documentation

See docs/ for the full index — pipeline & terminology, and development & benchmarking.

License

Licensed under the Apache License, Version 2.0 (see LICENSE).