ElderJS

GitHub access for Elder is currently limited to early partner projects and may not be available to everyone.

ElderJS is a JavaScript library designed to enable front-end integration for Rollapps connected to the Elder Ecosystem. It provides tools to interact with Ethereum and Cosmos-based wallets, facilitating transaction creation, signing, and broadcasting within the Elder framework.

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Features

• Ethereum Wallet Support: Create, sign, and broadcast transactions using Ethereum-based keys.

• Cosmos Wallet Support: Integrate with Keplr wallet for Cosmos-based transaction signing and broadcasting.

• Elder Ecosystem Integration: Seamlessly connect Rollapps to the Elder ecosystem with custom transaction handling.

• TypeScript Support: Fully typed codebase for better developer experience.

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Installation

Prerequisites

• Node.js (v16 or higher recommended)

• npm or yarn

• A modern browser with Web3 support (for Ethereum) or Keplr wallet (for Cosmos)

Install via npm

npm  install  elderjs

Install from GitHub

Clone the repository and install dependencies:

git  clone  https://github.com/0xElder/elderjs.git

cd  elderjs

npm  install

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Usage

Ethereum Wallet Example

import { eth_getElderMsgAndFeeTxRaw, eth_broadcastTx, eth_getElderAccountInfoFromSignature } from  'elderjs';
import { ethers } from "ethers";

function getWeb3Provider() {
    if (window.ethereum) {
        return new ethers.BrowserProvider(window.ethereum);
    }
    return null;
}
const provider = getWeb3Provider();

let  message  =  "Sign to Login";
const  signer  =  await  provider.getSigner();
const  signature  =  await  signer.signMessage(message);
var { recoveredPublicKey, elderAddr } =  await  eth_getElderAccountInfoFromSignature(message, signature)

// Example transaction data

const  tx = await  DUMMY_CONTRACT.METHOD.populateTransaction();

const  elderAddress = elderAddr;
const  elderPublicKey = recoveredPublicKey;

const  gasLimit = 21000;

const  elderChainConfig = {
	chainName:  "elder-testnet",
	rpc:  "https://rpc.elder.example.com",
	rest:  "https://rest.elder.example.com",
	rollChainID:  1234,
	
	// Elder Roll ID
	rollID:  2,
};

// Create and sign transaction

const { tx_hash, rawTx } = await  eth_getElderMsgAndFeeTxRaw(
    tx,
    elderAddress,
    elderPublicKey,
    gasLimit,
    ethers.parseEther("1.0"),
    elderChainConfig
);

// Broadcast transaction
// broadcastResult.code == 0 ( for tx success )

const  broadcastResult = await  eth_broadcastTx(rawTx, elderChainConfig.rpc);

console.log("Transaction Hash:", tx_hash);
console.log("Broadcast Result:", broadcastResult);

Cosmos Wallet Example (with Keplr)

import { cosmos_getElderClient, cosmos_getElderMsgAndFeeTxRaw, getEthereumAddressFromCosmosCompressedPubKey } from  'elderjs';

// Elder chain configuration

const  elderChainConfig = {
	chainName:  "elder-testnet",
	rpc:  "https://rpc.elder.example.com",
	rest:  "https://rest.elder.example.com",
	rollChainID:  1234,
	
	// Elder Roll ID
	rollID:  2,
};

// Connect to Keplr and get client

const { elderAddress, elderClient, elderPublicKey } = await  cosmos_getElderClient(elderChainConfig);
const  ethAddress  =  getEthereumAddressFromCosmosCompressedPubKey(elderPublicKey);
  
// Example transaction data
const  tx = await  DUMMY_CONTRACT.METHOD.populateTransaction();

// Create and sign transaction
const { tx_hash, rawTx } = await  cosmos_getElderMsgAndFeeTxRaw(
    tx,
    elderAddress,
    elderPublicKey,
    21000, // gasLimit
    ethers.parseEther("1.0"),
    1234, // rollChainId
    2, // ElderRollID
    "elder-testnet"  // chainName
);

// Broadcast transaction using the client
// broadcastResult.code == 0 ( for tx success )

const  broadcastResult = await  elderClient.broadcastTx(rawTx);

console.log("Transaction Hash:", tx_hash);
console.log("Broadcast Result:", broadcastResult);

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Project Structure

elderjs/

├── eth_wallet/

│ └── index.js # Ethereum wallet utilities

├── cosmos_wallet/

│ └── index.js # Cosmos wallet utilities (Keplr integration)

├── common/ # Shared utilities and helpers

├── package.json # Project metadata and dependencies

└── README.md # This file

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Dependencies

• ethers: Ethereum JavaScript library for transaction handling.

• @cosmjs/stargate: Cosmos SDK client for transaction signing and broadcasting.

• @cosmjs/proto-signing: Protobuf-based signing utilities for Cosmos.

• bech32: Bech32 address encoding/decoding.

• @noble/hashes: Cryptographic hash functions.

See package.json for the full list.

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Development

Transpile TypeScript

To transpile TypeScript files (if applicable):

npm  run  transpile-ts

Contributing

Contributions are welcome! Please follow these steps:

1. Fork the repository.

2. Create a feature branch (git checkout -b feature/your-feature).

3. Commit your changes (git commit -m "Add your feature").

4. Push to the branch (git push origin feature/your-feature).

5. Open a pull request.

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License

This project is licensed under the ISC License. See the LICENSE file for details.

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Issues

Found a bug? Have a suggestion? Open an issue on the GitHub Issues page.

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Contact

For questions or support, reach out via the GitHub repository.