@ethersproject/abi

What is @ethersproject/abi?

@ethersproject/abi is a part of the ethers.js library, which is a complete and compact library for interacting with the Ethereum blockchain and its ecosystem. The @ethersproject/abi package specifically deals with encoding and decoding data according to the Ethereum ABI (Application Binary Interface) specifications. This is essential for interacting with smart contracts, as it allows you to encode function calls and decode the data returned by smart contracts.

What are @ethersproject/abi's main functionalities?

Encoding Function Calls

This feature allows you to encode function calls to be sent to the Ethereum blockchain. In this example, the `transfer` function is encoded with the specified parameters.

const { Interface } = require('@ethersproject/abi');
const abi = [
  "function transfer(address to, uint amount)"
];
const iface = new Interface(abi);
const data = iface.encodeFunctionData("transfer", ["0x742d35Cc6634C0532925a3b844Bc454e4438f44e", 1000]);
console.log(data);

Decoding Function Results

This feature allows you to decode the results returned by a smart contract function call. In this example, the result of the `balanceOf` function is decoded.

const { Interface } = require('@ethersproject/abi');
const abi = [
  "function balanceOf(address owner) view returns (uint)"
];
const iface = new Interface(abi);
const result = iface.decodeFunctionResult("balanceOf", "0x00000000000000000000000000000000000000000000000000000000000003e8");
console.log(result);

Parsing Event Logs

This feature allows you to parse event logs emitted by smart contracts. In this example, a `Transfer` event log is parsed to extract the event details.

const { Interface } = require('@ethersproject/abi');
const abi = [
  "event Transfer(address indexed from, address indexed to, uint amount)"
];
const iface = new Interface(abi);
const log = {
  data: "0x00000000000000000000000000000000000000000000000000000000000003e8",
  topics: [
    "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
    "0x000000000000000000000000742d35cc6634c0532925a3b844bc454e4438f44e",
    "0x000000000000000000000000742d35cc6634c0532925a3b844bc454e4438f44e"
  ]
};
const event = iface.parseLog(log);
console.log(event);

Other packages similar to @ethersproject/abi

web3-eth-abi

The `web3-eth-abi` package is part of the Web3.js library, which is a collection of libraries that allow you to interact with a local or remote Ethereum node using HTTP, IPC, or WebSocket. The `web3-eth-abi` package provides similar functionalities for encoding and decoding data according to the Ethereum ABI specifications. Compared to @ethersproject/abi, Web3.js is a more comprehensive library but is generally considered to be heavier and less modular.

abi-decoder

The `abi-decoder` package is a lightweight library specifically designed for decoding Ethereum transaction data and logs. It is simpler and more focused compared to @ethersproject/abi, making it a good choice if you only need to decode data and do not require the full range of functionalities provided by ethers.js.

README

Application Binary Interface (ABI)

This is a beta version of the next release of ethers. Please do not use it in production yet.

This package handles encoding and deocding the binary format used by Solidity and other popular languages for EVM-based blockchain smart contracts.

License

MIT License.