Lof

Lof is a domain-specific language and end-to-end toolkit for authoring zero-knowledge circuits and producing Groth16 proofs over BN254. It couples a strong, security-focused type system with a Rust compiler for the .lof language, a proving and verification CLI, witness generator utilities, and JavaScript helpers for browser and Node runtimes.

Features

• Ergonomic .lof language with parser, type checker, and IR/R1CS back ends
• lof CLI to check, compile, and package circuits (including web-ready bundles) with rich diagnostics
• lofit CLI for Groth16 setup/proving/verification plus asset packaging
• Built-in WASM packaging for prover bundles (lof compile --target wasm, lofit package-web)
• Witness calculator generation via lof-witness-gen (Rust and WASM targets)
• Optional TypeScript toolkits for loading circuits in Node (@lof/toolkit-node) and browsers (@lof-lang/toolkit-browser)

Workspace Layout

• lof/ – compiler front-end and CLI for the Lof language
• lofit/ – proving, verification, and Web/WASM packaging tooling
• lof-witness-gen/ – IR-driven witness calculator generator
• packages/ – JavaScript toolkits for Node and browser integrations
• tests/ – integration fixtures plus shell runners for parser/typechecker/compiler suites

Getting Started

Prerequisites

• Rust toolchain (stable, via rustup)
• Optional: wasm-pack for building web prover bundles
• Optional: Node.js ≥ 18 if you plan to consume the JS toolkits

Build or Install the CLIs

cargo build --all
# or install the binaries locally
cargo install --path lof
cargo install --path lofit
cargo install --path lof-witness-gen
# make install (release build + version check) is also available
make install

A Minimal .lof Circuit

proof Multiply {
    input a: field;
    input b: field;
    let c = a * b in
    assert c === a * b;
    c
}

Typical Workflow

1. Type-check your source: lof check path/to/circuit.lof --verbose
2. Compile to R1CS and IR: lof compile path/to/circuit.lof --generate-templates
   • Produces build/, inputs/, keys/, and proofs/ directories alongside your source
   • JSON templates for public inputs and witness assignments land in inputs/
3. Generate keys (Groth16): lofit setup --input build/circuit.r1cs
4. Create a proof: lofit prove --input build/circuit.r1cs --public-inputs inputs/circuit_public.json --witness inputs/circuit_witness.json
5. Verify the proof: lofit verify --verification-key keys/circuit_vk.bin --proof proofs/circuit_proof.bin --public-inputs inputs/circuit_public.json

The lof compile command requires a .lof extension and can be re-run safely; artifacts in the source directory are refreshed each time.

Web / WASM Packaging

• Quick bundle generation: lof compile circuit.lof --target wasm --output dist/circuit
• Standalone packaging via lofit: lofit package-web --input build/circuit.r1cs --output dist/circuit --skip-wasm

Both paths create a directory containing R1CS, Groth16 keys, witness calculator sources, and the prover WASM bundle. When wasm-pack is installed the prover bindings are rebuilt; otherwise the tool falls back to the prebuilt artifacts shipped with lofit.

Node and Browser Toolkits

• packages/toolkit-node exposes helpers for loading verification keys and verifying proofs in Node environments
• packages/toolkit-browser wraps the web assets emitted by lof compile --target wasm with ergonomic TypeScript APIs

Consult each package's README for API details and usage examples.

Running Tests

• cargo test --all runs Rust unit tests across the workspace
• make test-fast executes formatting, linting, and unit suites
• make test-integration (or the individual scripts under tests/scripts/) runs parser, typechecker, and compiler integration checks against the .lof fixtures

Development Tips

• cargo fmt --all and cargo clippy --all-targets --all-features keep the codebase tidy
• Use make help to list the most common development and verification commands
• Verbose compiler output (--verbose) is useful when diagnosing parser/typechecker issues

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE)
• MIT License (LICENSE-MIT)

at your option.