@cygnus-wealth/evm-integration

Framework-agnostic TypeScript library for read-only EVM blockchain data access. Returns all data in standardized @cygnus-wealth/data-models format.

🚀 Quick Start - Live Demo

Want to see it in action? Run the live demo with one command:

npm run demo

This opens a web UI where you can:

• ✅ Connect your MetaMask wallet
• ✅ See live balance updates from Sepolia testnet via WebSocket
• ✅ Watch balances change in real-time (updates on every new block)
• ✅ Test with any Ethereum address
• ✅ Visual indicator showing WebSocket connection status

The demo includes step-by-step instructions right on the page!

---

Features

• 🔌 Multi-chain Support - Ethereum, Polygon, Arbitrum, Optimism, Base, and more
• 📊 Standardized Data - All responses use @cygnus-wealth/data-models types
• 🚀 Framework Agnostic - Use with React, Vue, Node.js, or vanilla JavaScript
• 🔄 Real-time Updates - WebSocket support for live balance monitoring
• 🛡️ Read-only - Safe, no transaction signing or private keys
• ⚡ TypeScript First - Full type safety and IntelliSense support

Installation

npm install @cygnus-wealth/evm-integration

Quick Start

import { defaultRegistry } from '@cygnus-wealth/evm-integration';

// Get adapter for Ethereum mainnet
const adapter = defaultRegistry.getAdapter(1);

// Fetch balance
const balance = await adapter.getBalance('0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb7');
console.log(`Balance: ${balance.amount} ${balance.asset?.symbol}`);

Core API

Using the Registry (Recommended)

import { defaultRegistry } from '@cygnus-wealth/evm-integration';

// Get adapter for any supported chain
const ethereum = defaultRegistry.getAdapter(1);
const polygon = defaultRegistry.getAdapter(137);
const arbitrum = defaultRegistry.getAdapter(42161);

// All adapters share the same interface
const balance = await ethereum.getBalance(address);
const tokens = await polygon.getTokenBalances(address);

Direct Adapter Usage

import { EvmChainAdapter } from '@cygnus-wealth/evm-integration';

const adapter = new EvmChainAdapter({
  id: 1,
  name: 'Ethereum',
  symbol: 'ETH',
  decimals: 18,
  endpoints: {
    http: ['https://eth-mainnet.public.blastapi.io'],
    ws: ['wss://eth-mainnet.public.blastapi.io']
  },
  explorer: 'https://etherscan.io'
});

await adapter.connect();
const balance = await adapter.getBalance(address);

Supported Chains

Chain	Chain ID	Symbol
Ethereum	1	ETH
Polygon	137	MATIC
Arbitrum	42161	ETH
Optimism	10	ETH
Base	8453	ETH

Examples

Get Token Balances

const adapter = defaultRegistry.getAdapter(1);

const tokenBalances = await adapter.getTokenBalances(
  '0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb7',
  [
    { address: '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48', symbol: 'USDC' },
    { address: '0xdAC17F958D2ee523a2206206994597C13D831ec7', symbol: 'USDT' }
  ]
);

tokenBalances.forEach(balance => {
  console.log(`${balance.asset?.symbol}: ${balance.amount}`);
});

Real-time Balance Updates

const adapter = defaultRegistry.getAdapter(1);

const unsubscribe = await adapter.subscribeToBalance(
  address,
  (balance) => {
    console.log('Balance updated:', balance.amount);
  }
);

// Stop watching
unsubscribe();

Multi-chain Balance Check

const chains = [1, 137, 42161, 10, 8453];

const balances = await Promise.all(
  chains.map(async (chainId) => {
    const adapter = defaultRegistry.getAdapter(chainId);
    return adapter.getBalance(address);
  })
);

Framework Integration

This library is framework-agnostic. For framework-specific integrations:

• React: Use @cygnus-wealth/evm-integration-react (coming soon)
• Vue: Use @cygnus-wealth/evm-integration-vue (coming soon)
• Node.js/CLI: Use directly as shown in examples

API Reference

IChainAdapter Interface

interface IChainAdapter {
  getBalance(address: Address): Promise<Balance>
  getTokenBalances(address: Address, tokens?: TokenConfig[]): Promise<Balance[]>
  getTransactions(address: Address, options?: TransactionOptions): Promise<Transaction[]>
  subscribeToBalance(address: Address, callback: (balance: Balance) => void): Promise<Unsubscribe>
  connect(): Promise<void>
  disconnect(): void
  getChainInfo(): ChainInfo
  isHealthy(): Promise<boolean>
}

All methods return types from @cygnus-wealth/data-models.

Adding Custom Chains

Create a JSON configuration file:

{
  "id": 56,
  "name": "BNB Smart Chain",
  "symbol": "BNB",
  "decimals": 18,
  "endpoints": {
    "http": ["https://bsc-dataseed.binance.org"],
    "ws": ["wss://bsc-ws-node.nariox.org"]
  },
  "explorer": "https://bscscan.com"
}

Then register it:

import { ChainRegistry } from '@cygnus-wealth/evm-integration';
import bscConfig from './bsc-config.json';

const registry = new ChainRegistry();
registry.registerChain(bscConfig);

const bscAdapter = registry.getAdapter(56);

Architecture

See ARCHITECTURE.md for detailed technical architecture.

Development

# Install dependencies
npm install

# Build library
npm run build

# Run tests
npm test

# Run test UI
npm run dev:ui

Contributing

For Contributors & Developers: Please start with DEVELOPERS.md for complete documentation, architecture, and implementation guidelines.

Contributions are welcome! Please:

1. Read DEVELOPERS.md for architecture and conventions
2. Follow the implementation roadmap and quality standards
3. Write tests alongside your implementation
4. Ensure all tests pass and coverage is ≥80%

License

MIT