---
id: faster-eth-abi
version: "5.2.31"
license: MIT
license_treatment: permissive
maintenance: active
---

# faster-eth-abi — A ~2-6x faster fork of eth_abi: Python utilities for working with Ethereum ABI definitions, especially encoding and decoding. Implemented in C.

License: permissive · Maintenance: active · Downloads: 223.1K/mo

## What it is and what it does

faster-eth-abi is a C-compiled fork of eth-abi that encodes and decodes Ethereum contract ABI data—the binary format used to call smart contracts and interpret their return values. It maintains API and exception compatibility with eth-abi, so you can swap it in as a drop-in replacement without rewriting exception handlers or call sites. The package depends on cchecksum, faster-eth-utils, eth-abi, eth-typing, mypy_extensions, and parsimonious to handle checksum validation, type annotations, and parsing.

The fork targets performance-critical Ethereum applications where encoding/decoding throughput matters. It compiles hot paths to C while keeping the Python interface unchanged. The project is actively maintained and tracks upstream eth-abi releases, so new ABI features and bug fixes are incorporated. It supports Python 3.10 through 3.14 on CPython with pre-built wheels for macOS (ARM), Linux (x86_64, i686, musl), and Windows.

Use it for:

- Speed up batch transaction encoding in high-frequency trading or arbitrage bots that process many contract calls per second.
- Reduce latency in RPC middleware or indexing services that decode contract events and call results at scale.
- Improve performance of local contract simulators or testing frameworks that repeatedly encode/decode ABI data.
- Replace eth-abi in existing Ethereum libraries or applications without refactoring exception handling or API calls.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

Encodes and decodes Ethereum ABI data structures with C-compiled performance, providing a faster drop-in replacement for eth-abi with compatible exception handling.

Yes, if you are already using eth-abi and need faster encoding/decoding performance. The drop-in compatibility and active maintenance make it a low-risk swap. No if you are not performance-constrained or if you need Python versions below 3.10. The medium install friction (compiled wheels) is offset by broad platform coverage and permissive licensing.

## Install

pip install faster-eth-abi
uv add faster-eth-abi
poetry add faster-eth-abi

## Installing faster-eth-abi

Before you install: Medium install friction due to compiled wheels across multiple platforms and Python versions (3.10–3.14). Active maintenance with recent releases; last commit 2026-08-11. Six runtime dependencies add some complexity, though the project tracks upstream eth-abi updates.

License in practice: MIT license permits commercial and private use with minimal restrictions; you may use, modify, and distribute this package freely provided you include the license notice.

Quickstart:

pip install faster-eth-abi

from eth_abi import encode, decode
# Encode and decode contract ABI data

Requires Python 3.10 or later; compiled wheels available for common platforms but may require build tools on unsupported architectures.

Verify before relying:

- Actual performance improvement magnitude (2–6x claimed) on real workloads and whether it varies significantly by operation type.
- Compatibility guarantees with eth-abi beyond exception inheritance; whether all encoding/decoding edge cases are identical.
- Whether the C implementation handles all Ethereum type variants that eth-abi supports.

## Package facts

- License: MIT (permissive)
- Python support: supports_current
- Install friction: medium
- Maintenance: active
- Downloads: 223.1K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

ethereum abi encoding decoding, eth-abi faster alternative, ethereum contract interface utilities, abi data serialization, ethereum type encoding, ethereum, performance-optimized, abi-encoding

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