rWasm (Reduced WebAssembly)

rwasm is a deterministic reduced WebAssembly format + runtime stack for execution environments that care about * performance*, predictability, and proof-friendliness.

It is designed to be ZK-friendly: execution semantics and representation choices aim to stay efficient both for normal execution and proving-oriented pipelines.

What this repository provides

• Wasm → rWasm compilation pipeline
• rWasm opcode model and module encoding
• native rWasm VM runtime with fuel support
• strategy abstraction for native execution and optional Wasmtime backend
• host import/syscall integration surfaces

Documentation

Start with docs/README.md.

Core docs:

• Architecture
• Compilation & Execution Pipeline
• Module Format
• VM, Fuel, and Tracing
• Opcode Specification
• Security Considerations
• Contributor Guide

Quick start (local)

Prerequisites

• Rust stable
• Rust nightly nightly-2025-09-20
• wasm target wasm32-unknown-unknown on both toolchains
• clang, libclang-dev, pkg-config
• initialized git submodules

Setup

rustup target add wasm32-unknown-unknown
rustup +nightly-2025-09-20 target add wasm32-unknown-unknown
git submodule update --init --recursive

Canonical commands

make build
make clippy
make test

Feature notes

Cargo.toml defines the runtime surface via features. Important points:

• default enables std, wasmtime
• fpu exists as a feature-gated surface in code
• FPU opcodes are currently not treated as production-facing opcode surface in docs (kept mainly for testsuite/internal compatibility)

When integrating in production, pin exact feature set and toolchain.

Repository layout

• src/ — compiler, module model, opcode types, VM, strategy layer
• e2e/ — end-to-end harnesses and testsuite integration
• snippets/ — snippet fixtures/tests (nightly path)
• examples/ — sample modules/programs
• benches/ — Criterion benchmarks
• .github/workflows/ — CI/CD workflows

License

Apache 2.0