Ethereum smart contract transaction input data decoder
https://lab.miguelmota.com/ethereum-input-data-decoder
npm install ethereum-input-data-decoder
Pass ABI file path to decoder constructor:
const InputDataDecoder = require('ethereum-input-data-decoder');
const decoder = new InputDataDecoder(`${__dirname}/abi.json`);
Alternatively, you can pass ABI array object to constructor;
const abi = [{ ... }]
const decoder = new InputDataDecoder(abi);
Then you can decode input data:
const data = `0x67043cae0000000000000000000000005a9dac9315fdd1c3d13ef8af7fdfeb522db08f020000000000000000000000000000000000000000000000000000000058a20230000000000000000000000000000000000000000000000000000000000040293400000000000000000000000000000000000000000000000000000000000000a0f3df64775a2dfb6bc9e09dced96d0816ff5055bf95da13ce5b6c3f53b97071c800000000000000000000000000000000000000000000000000000000000000034254430000000000000000000000000000000000000000000000000000000000`;
const result = decoder.decodeData(data);
console.log(result);
{
"method": "registerOffChainDonation",
"types": [
"address",
"uint256",
"uint256",
"string",
"bytes32"
],
"inputs": [
<BN: 5a9dac9315fdd1c3d13ef8af7fdfeb522db08f02>,
<BN: 58a20230>,
<BN: 402934>,
"BTC",
<Buffer f3 df ... 71 c8>
],
"names": [
"addr",
"timestamp",
"chfCents",
"currency",
"memo"
]
}
Example using input response from web3.getTransaction:
web3.eth.getTransaction(txHash, (error, txResult) => {
const result = decoder.decodeData(txResult.input);
console.log(result);
});
All numbers are returned in big number format to preserve precision.
Here's an example of how to convert the big number to a human readable format.
console.log(result.inputs[0].toString(10)) // "5"
console.log(result.inputs[0].toNumber()) // 55
Please keep in mind that JavaScript only supports numbers up to 64 bits. Solidity numbers can be up to 256 bits, so you run the risk of truncation when casting or having the big number library error out when trying to parse a large number to a JavaScript Number type.
const n = new BN("543534254523452352345234523455")
console.log(n.toString(10)) // "543534254523452352345234523455"
console.log(n.toNumber()) // ERROR!
npm install -g ethereum-input-data-decoder
$ ethereum_input_data_decoder --help
Ethereum smart contract transaction input data decoder
Usage
$ ethereum_input_data_decoder [flags] [input]
Options
--abi, -a ABI file path
--input, -i Input data file path
Examples
$ ethereum_input_data_decoder --abi token.abi --input data.txt
$ ethereum_input_data_decoder --abi token.abi "0x23b872dd..."
Pass ABI file and input data as file:
$ ethereum_input_data_decoder --abi abi.json --input data.tx
method registerOffChainDonation
address addr 0x5a9dac9315fdd1c3d13ef8af7fdfeb522db08f02
uint256 timestamp 1487012400
uint256 chfCents 4204852
string currency BTC
bytes32 memo 0xf3df64775a2dfb6bc9e09dced96d0816ff5055bf95da13ce5b6c3f53b97071c8
Pass ABI file and input data as string:
$ ethereum_input_data_decoder --abi abi.json 0x67043cae0...000000
method registerOffChainDonation
address addr 0x5a9dac9315fdd1c3d13ef8af7fdfeb522db08f02
uint256 timestamp 1487012400
uint256 chfCents 4204852
string currency BTC
bytes32 memo 0xf3df64775a2dfb6bc9e09dced96d0816ff5055bf95da13ce5b6c3f53b97071c8
You can also pipe the input data:
$ cat data.txt | ethereum_input_data_decoder --abi abi.json
method registerOffChainDonation
address addr 0x5a9dac9315fdd1c3d13ef8af7fdfeb522db08f02
uint256 timestamp 1487012400
uint256 chfCents 4204852
string currency BTC
bytes32 memo 0xf3df64775a2dfb6bc9e09dced96d0816ff5055bf95da13ce5b6c3f53b97071c8
npm test
- Clone repository:
git clone [email protected]:miguelmota/ethereum-input-data-decoder.git
cd ethereum-input-data-decoder/
- Install dependencies:
npm install
-
Make changes.
-
Run tests:
npm test
- Run linter:
npm run lint:fix
-
Q: How can I retrieve the ABI?
-
A: You can generate the ABI from the solidity source files using the Solidity Compiler.
solc --abi MyContract.sol -o build
-
-
Q: Can this library decode contract creation input data?
- A: Yes, it can decode contract creation input data.
-
Q: Does this library support ABIEncoderV2?
- A: Yes, but it's buggy. Please submit a bug report if you encounter issues.