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

cargo install ethabi-cli

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"
}]