ethabi

The ABI, Application Binary Interface, is basically how you call functions in a contract and get data back.

An ABI determines such details as how functions are called and in which binary format information should be passed from one program component to the next...

An Ethereum smart contract is bytecode, EVM, on the Ethereum blockchain. Among the EVM, there could be several functions in a contract. An ABI is necessary so that you can specify which function in the contract to invoke, as well as get a guarantee that the function will return data in the format you are expecting. read more

This library encodes function calls and decodes their output.

Documentation

Disclaimer

This library intends to support only valid ABIs generated by recent Solidity versions. Specifically, we don't intend to support ABIs that are invalid due to known Solidity bugs or by external libraries that don't strictly follow the specification. Please make sure to pre-process your ABI in case it's not supported before using it with ethabi.

Installation

• via cargo

  cargo install ethabi-cli
  

• via homebrew

  brew tap paritytech/paritytech
  brew install ethabi
  

Usage

Ethereum ABI coder.
  Copyright 2016-2017 Parity Technologies (UK) Limited

Usage:
    ethabi encode function <abi-path> <function-name-or-signature> [-p <param>]... [-l | --lenient]
    ethabi encode params [-v <type> <param>]... [-l | --lenient]
    ethabi decode function <abi-path> <function-name-or-signature> <data>
    ethabi decode params [-t <type>]... <data>
    ethabi decode log <abi-path> <event-name-or-signature> [-l <topic>]... <data>
    ethabi -h | --help

Options:
    -h, --help         Display this message and exit.
    -l, --lenient      Allow short representation of input params.

Commands:
    encode             Encode ABI call.
    decode             Decode ABI call result.
    function           Load function from json ABI file.
    params             Specify types of input params inline.
    log                Decode event log.

Examples

ethabi encode params -v bool 1

0000000000000000000000000000000000000000000000000000000000000001

--

ethabi encode params -v bool 1 -v string gavofyork -v bool 0

00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000096761766f66796f726b0000000000000000000000000000000000000000000000

--

ethabi encode params -v bool[] [1,0,false]

00000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000003000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

--

ethabi encode params -v '(string,bool,string)' '(test,1,cyborg)'

00000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000000000000a00000000000000000000000000000000000000000000000000000000000000004746573740000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000066379626f72670000000000000000000000000000000000000000000000000000

--

ethabi encode function examples/test.json foo -p 1

[{
	"type":"function",
	"inputs": [{
		"name":"a",
		"type":"bool"
	}],
	"name":"foo",
	"outputs": []
}]

455575780000000000000000000000000000000000000000000000000000000000000001

--

ethabi encode function examples/test.json foo(bool) -p 1

[{
	"type":"function",
	"inputs": [{
		"name":"a",
		"type":"bool"
	}],
	"name":"foo",
	"outputs": []
}]

455575780000000000000000000000000000000000000000000000000000000000000001

--

ethabi encode function examples/test.json bar(bool) -p 1

[{
	"type":"function",
	"inputs": [{
		"name":"a",
		"type":"bool"
	}],
	"name":"foo",
	"outputs": []
}]

6fae94120000000000000000000000000000000000000000000000000000000000000001

--

ethabi encode function examples/test.json bar(string):(uint256) -p 1

[{
	"type":"function",
	"inputs": [{
		"type":"string"
	}],
	"name":"foo",
	"outputs": [{
		"type": "uint256"
	}]
}]

d473a8ed000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000013100000000000000000000000000000000000000000000000000000000000000

--

ethabi decode params -t bool 0000000000000000000000000000000000000000000000000000000000000001

bool true

--

ethabi decode params -t bool -t string -t bool 00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000096761766f66796f726b0000000000000000000000000000000000000000000000

bool true
string gavofyork
bool false

--

ethabi decode params -t bool[] 00000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000003000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

bool[] [true,false,false]

--

ethabi decode params -t '(string,bool,string)' 00000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000000000000a0000000000000000000000000000000000000000000000000000000000000000673706972616c000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000067175617361720000000000000000000000000000000000000000000000000000```

(string,bool,string) (spiral,true,quasar)

--

ethabi decode function ./examples/foo.json bar 0000000000000000000000000000000000000000000000000000000000000001

[{
	"constant":false,
	"inputs":[{
		"name":"hello",
		"type":"address"
	}],
	"name":"bar",
	"outputs":[{
		"name":"",
		"type":"bool"
	}],
	"type":"function"
}]

bool true

--

ethabi decode log ./examples/event.json Event -l 0000000000000000000000000000000000000000000000000000000000000001 0000000000000000000000004444444444444444444444444444444444444444

a bool true
b address 4444444444444444444444444444444444444444

Alternative tools

• ethabi-js - javascript port of this library created by @jacogr

Parity Ethereum toolchain

In addition to the Parity Ethereum client, there are additional tools in this repository available:

• evmbin - EVM implementation for Parity Ethereum.
• ethabi - Parity Ethereum function calls encoding.
• ethstore - Parity Ethereum key management.
• ethkey - Parity Ethereum keys generator.
• whisper - Implementation of Whisper-v2 PoC.