Getting Started

Requirements

• TypeScript 5.x
• exactOptionalPropertyTypes and strict enabled in your tsconfig.json

Dependencies

To get started, install the package from npm, along with its peer dependencies:

npm i @3loop/transaction-decoder

Quick Start

To begin using the Loop Decoder, you need to create an instance of the LoopDecoder class. At a minimum, you must provide three data loaders:

1. getPublicClient: This function returns an object with Viem PublicClient based on the chain ID.

const getPublicClient = (chainId: number) => {
    return {
        client: createPublicClient({
            transport: http(RPC_URL[chainId]),
        }),
    }
}

2. contractMetaStore: This object has 2 properties get and set that returns and caches contract meta-information. See the ContractData type for the required properties.

const db = {}; // Your data source

const contractMetaStore = {
  get: async (req: {
    address: string
    chainID: number
  }) => {
    return db.getContractMeta(req)
  },
  set: async (req: {
    address: string
    chainID: number
  }) {
    // NOTE: ignore for now
  },
}

3. abiStore: Similarly, this object has 2 properties get and set that returns and cache the contract or fragment ABI based on the chain ID, address, and/or signature.

const db = {} // Your data source

const abiStore = {
    get: async (req: {
        chainID: number
        address: string
        event?: string | undefined
        signature?: string | undefined
    }) => {
        return db.getContractAbi(req)
    },
    set: async (req: { address?: Record<string, string>; signature?: Record<string, string> }) => {
        await db.setContractAbi(req)
    },
}

Finally, you can create a new instance of the LoopDecoder class:

import { TransactionDecoder } from '@3loop/transaction-decoder'

const decoded = new TransactionDecoder({
    getProvider: getPublicClient,
    abiStore: abiStore,
    contractMetaStore: contractMetaStore,
})

It’s important to note that the Loop Decoder does not enforce any specific data source, allowing users of the library to load contract data as they see fit. Depending on the requirements of your application, you can either include the necessary data directly in your code for a small number of contracts or use a database as a cache.

LoopDecoder instances provide a public method, decodeTransaction, which fetches and decodes a given transaction:

const result = await decoded.decodeTransaction({
    chainID: 5,
    hash: '0x...',
})