zabi-rs

Zero-Allocation ABI Decoder for Rust.

zabi-rs is a high-performance, #![no_std] compatible library designed for decoding Ethereum Virtual Machine (EVM) ABI encoded data without any heap allocation.

Unlike standard libraries like ethers-rs or alloy-rs which decode data into owned types (Vec, String, BigInt), zabi-rs maps Rust structs directly to the underlying raw byte slice (&'a [u8]) using explicit lifetimes.

Features

• 🚀 Zero Allocation: No malloc, no Box, no Vec. All outcomes are references.
• ⚡ High Performance: Designed for hot-path decoding, MEV bots, and embedded environments.
• 🛡️ Safe & Unsafe Encapsulation: Uses pointer arithmetic for speed but provides safe wrappers with bounds checking.
• 🔧 no_std Compatible: Ready for strict embedded or WASM environments.
• 📦 Primitive Support: address, uint256, bytes (Basic types supported currently).

Performance

Installation

Add this to your Cargo.toml:

[dependencies]
zabi-rs = "0.0.4"

Usage

use zabi_rs::{read_u256, read_address_from_word};

fn main() -> Result<(), zabi_rs::ZError> {
    // Example: A raw ABI encoded byte array (mocked)
    // 32 bytes for uint256(1) + 32 bytes for address
    let mut data = [0u8; 64];
    data[31] = 1; // uint256 = 1
    data[44] = 0xaa; // address starts at offset 44 (12 padding + 20 bytes)
    
    // Decode without copying
    // Returns ZU256<'a> which wraps the slice
    let value = read_u256(&data, 0)?;
    
    // Returns ZAddress<'a>
    let sender = read_address_from_word(&data, 32)?;
    
    println!("decoded value: {:?}", value);
    println!("decoded sender: {:?}", sender);
    
    Ok(())
}

Testing

Run the test suite:

cargo test

License

MIT

Roadmap

See docs/roadmap.md for future plans.