fastabi — ABI Codec for EVM

A high-performance ABI encoder/decoder for EVM chains. No go-ethereum dependency.

Features

• ABIv2 — all Solidity types: uint8–uint256, int8–int256, address, bool, bytes, bytes32, string, arrays, nested tuples
• Zero-alloc — pooled Decoder/Encoder via sync.Pool, no heap allocations per call after warm-up
• U256 — wraps holiman/uint256 inline (no pointer, GC-friendly), with pooling for hot paths
• Signature parser — ParseFunction("transfer(address,uint256)") → name + parameter types
• Keccak256 — 4-byte selectors from function signatures
• Wad math — WadMul, WadDiv, WadLn for DeFi fixed-point arithmetic

Quick Start

import "github.com/cryptoddev/fastabi"

// Encode a single uint256
data := fastabi.Encode1(fastabi.TUint256(), uint64(42))

// Decode
val, _ := fastabi.Decode1(fastabi.TUint256(), data)
u := val.(*fastabi.U256)

// Pooled low-level API for hot paths
enc := fastabi.GetEncoder()
defer fastabi.PutEncoder(enc)
enc.EncodeUint64(42)
data = enc.Bytes()

Types

Constructor	Solidity	Go Type
TUint<N>()	uint8–uint256	uint64, *big.Int, *U256
TInt<N>()	int8–int256	int64, *big.Int
TAddress()	address	[20]byte, Address
TBool()	bool	bool
TBytes()	bytes	[]byte
TBytes32()	bytes32/bytesN	[32]byte
TString()	string	string
TArray(elem)	type[]	[]any
TFixedArray(elem, n)	type[n]	[]any
TTuple(...)	(a,b,c)	[]any

Testing

go test ./...
go test -bench=. ./...

License

MIT