eth.zig

The fastest Ethereum library. Beats Rust's alloy.rs on 20 out of 26 benchmarks.

A complete Ethereum client library written in Zig -- ABI encoding, RLP serialization, secp256k1 signing, Keccak-256 hashing, HD wallets, ERC-20/721 tokens, JSON-RPC, ENS, and more. Just zig build.

Read the docs at ethzig.org

Why eth.zig?

Fastest Ethereum library -- eth.zig beats alloy.rs (Rust's leading Ethereum library, backed by Paradigm) on 20 out of 26 benchmarks. ABI decoding up to 7.94x faster, Keccak hashing up to 1.34x, u256 division 4x, UniswapV2 getAmountOut 1.30x, transaction hashing 1.27x. See the full results.

Comptime-first -- Function selectors and event topics are computed at compile time with zero runtime cost. The compiler does the hashing so your program doesn't have to.

Complete -- ABI, RLP, secp256k1, Keccak-256, BIP-32/39/44 HD wallets, EIP-712, JSON-RPC, WebSocket, ENS, ERC-20/721 -- everything you need for Ethereum in one package.

Performance vs alloy.rs

eth.zig wins 20/26 benchmarks against alloy.rs. Measured on Apple Silicon, ReleaseFast (Zig) vs --release (Rust). Criterion-style harness with 0.5s warmup and 2s measurement.

Operation	eth.zig	alloy.rs	Winner
Keccak-256 (32B)	135 ns	179 ns	zig 1.33x
Keccak-256 (4KB)	4,097 ns	4,826 ns	zig 1.18x
ABI encode (static)	13 ns	51 ns	zig 3.92x
ABI encode (dynamic)	91 ns	171 ns	zig 1.88x
ABI decode (uint256)	8 ns	26 ns	zig 3.25x
ABI decode (dynamic)	17 ns	135 ns	zig 7.94x
Address derivation	136 ns	190 ns	zig 1.40x
Checksum address	161 ns	201 ns	zig 1.25x
u256 multiply	2 ns	5 ns	zig 2.50x
u256 division	3 ns	12 ns	zig 4.00x
UniswapV2 getAmountOut	10 ns	13 ns	zig 1.30x
UniswapV4 swap	22 ns	24 ns	zig 1.09x
Hex encode (32B)	11 ns	12 ns	zig 1.09x
Hex decode (32B)	12 ns	14 ns	zig 1.17x
TX hash (EIP-1559)	170 ns	216 ns	zig 1.27x

alloy.rs wins on secp256k1 signing (3.09x -- large precomputed EC tables), address hex parsing (1.33x -- SIMD), and u256 mulDiv (1.20x). See full results.

Quick Start

Derive an address from a private key

const eth = @import("eth");

const private_key = try eth.hex.hexToBytesFixed(32, "ac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80");
const signer = eth.signer.Signer.init(private_key);
const addr = try signer.address();
const checksum = eth.primitives.addressToChecksum(&addr);
// "0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266"

Sign and send a transaction

const eth = @import("eth");

var transport = eth.http_transport.HttpTransport.init(allocator, "https://rpc.example.com");
defer transport.deinit();
var provider = eth.provider.Provider.init(allocator, &transport);

var wallet = eth.wallet.Wallet.init(allocator, private_key, &provider);
const tx_hash = try wallet.sendTransaction(.{
    .to = recipient_address,
    .value = eth.units.parseEther(1.0),
});

Read an ERC-20 token

const eth = @import("eth");

// Comptime selectors -- zero runtime cost
const balance_sel = eth.erc20.selectors.balanceOf;

// Or use the typed wrapper
var token = eth.erc20.ERC20.init(allocator, token_addr, &provider);
const balance = try token.balanceOf(holder_addr);
const name = try token.name();
defer allocator.free(name);

Function selectors and event topics

const eth = @import("eth");

// Computed at compile time -- zero runtime cost
const transfer_sel = comptime eth.keccak.selector("transfer(address,uint256)");
// transfer_sel == [4]u8{ 0xa9, 0x05, 0x9c, 0xbb }

// Same function works at runtime too
const runtime_sel = eth.keccak.selector(runtime_signature);

const transfer_topic = comptime eth.keccak.hash("Transfer(address,address,uint256)");
// transfer_topic == keccak256("Transfer(address,address,uint256)")

HD wallet from mnemonic

const eth = @import("eth");

const words = [_][]const u8{
    "abandon", "abandon", "abandon", "abandon",
    "abandon", "abandon", "abandon", "abandon",
    "abandon", "abandon", "abandon", "about",
};
const seed = try eth.mnemonic.toSeed(&words, "");
const key = try eth.hd_wallet.deriveEthAccount(seed, 0);
const addr = key.toAddress();

Installation

One-liner:

zig fetch --save git+https://github.com/StrobeLabs/eth.zig.git#v0.2.2

Or add manually to your build.zig.zon:

.dependencies = .{
    .eth = .{
        .url = "git+https://github.com/StrobeLabs/eth.zig.git#v0.2.2",
        .hash = "...", // run `zig build` and it will tell you the expected hash
    },
},

Then import in your build.zig:

const eth_dep = b.dependency("eth", .{
    .target = target,
    .optimize = optimize,
});
exe.root_module.addImport("eth", eth_dep.module("eth"));

Examples

The examples/ directory contains self-contained programs demonstrating each major feature:

Example	Description	Requires RPC
01_derive_address	Derive address from private key	No
02_check_balance	Query ETH balance via JSON-RPC	Yes
03_sign_message	EIP-191 personal message signing	No
04_send_transaction	Send ETH with Wallet	Yes (Anvil)
05_read_erc20	ERC-20 module API showcase	Yes
06_hd_wallet	BIP-44 HD wallet derivation	No
07_comptime_selectors	Comptime function selectors	No

Run any example:

cd examples && zig build && ./zig-out/bin/01_derive_address

Modules

Layer	Modules	Description
Primitives	primitives, uint256, hex	Address, Hash, Bytes32, u256, hex encoding
Encoding	rlp, abi_encode, abi_decode, abi_types	RLP and ABI encoding/decoding
Crypto	secp256k1, signer, signature, keccak, eip155	ECDSA signing (RFC 6979), Keccak-256, EIP-155
Types	transaction, receipt, block, blob, access_list	Legacy, EIP-2930, EIP-1559, EIP-4844 transactions
Accounts	mnemonic, hd_wallet	BIP-32/39/44 HD wallets and mnemonic generation
Transport	http_transport, ws_transport, json_rpc, provider, subscription	HTTP and WebSocket JSON-RPC transports
ENS	ens_namehash, ens_resolver, ens_reverse	ENS name resolution and reverse lookup
Client	wallet, contract, multicall, event, erc20, erc721	Signing wallet, contract interaction, Multicall3, token wrappers
Standards	eip712, abi_json	EIP-712 typed data signing, Solidity JSON ABI parsing
Chains	chains	Ethereum, Arbitrum, Optimism, Base, Polygon definitions

Features

Feature	Status
Primitives (Address, Hash, u256)	Complete
RLP encoding/decoding	Complete
ABI encoding/decoding (all Solidity types)	Complete
Keccak-256 hashing	Complete
secp256k1 ECDSA signing (RFC 6979, EIP-2 low-S)	Complete
Transaction types (Legacy, EIP-2930, EIP-1559, EIP-4844)	Complete
EIP-155 replay protection	Complete
EIP-191 personal message signing	Complete
EIP-712 typed structured data signing	Complete
EIP-55 address checksums	Complete
BIP-32/39/44 HD wallets	Complete
HTTP transport	Complete
WebSocket transport (with TLS)	Complete
JSON-RPC provider (24+ methods)	Complete
ENS resolution (forward + reverse)	Complete
Contract read/write helpers	Complete
Multicall3 batch calls	Complete
Event log decoding and filtering	Complete
Chain definitions (5 networks)	Complete
Unit conversions (Wei/Gwei/Ether)	Complete
ERC-20 typed wrapper	Complete
ERC-721 typed wrapper	Complete
JSON ABI parsing	Complete
EIP-7702 transactions	Planned
IPC transport	Planned
Provider middleware (retry, caching)	Planned
Hardware wallet signers	Planned

Comparison with Other Libraries

Performance vs alloy.rs (Rust)

Category	eth.zig	alloy.rs
Benchmarks won	20/26	4/26
ABI encoding/decoding	Faster (2.23-7.94x)	--
Hashing (Keccak)	Faster (1.18-1.34x)	--
u256 arithmetic	Faster on add/mul/div/V2/V4	Faster on mulDiv (1.20x)
Hex operations	Faster (1.09-1.17x)	--
secp256k1 signing	--	Faster (3.09x, larger precomputed tables)

Features vs Zabi (Zig)

Feature	eth.zig	Zabi
Comptime selectors	Yes	No
Pure Zig secp256k1	Yes	No (C binding)
ABI encode/decode	Yes	Yes
HD wallets (BIP-32/39/44)	Yes	Yes
ERC-20/721 wrappers	Yes	No
JSON ABI parsing	Yes	Yes
WebSocket transport	Yes	Yes
ENS resolution	Yes	Yes
EIP-712 typed data	Yes	Yes
Multicall3	Yes	No

Requirements

• Zig >= 0.15.2

Running Tests

zig build test                # Unit tests
zig build integration-test    # Integration tests (requires Anvil)

Benchmarks

One command to run the full comparison (requires Zig, Rust, Python 3):

bash bench/compare.sh

Or run individually:

zig build bench          # eth.zig only

Contributing

Contributions are welcome. Please open an issue or pull request on GitHub.

Before submitting:

1. Run zig build test and ensure all tests pass.
2. Follow the existing code style -- comptime where possible.
3. Add tests for any new functionality.

License

MIT -- see LICENSE for details.

Copyright 2025-2026 Strobe Labs