@etherspot/free-bundler

A TypeScript library for creating ERC-4337 bundler clients with preconfigured free endpoints.

Features

• 🚀 Zero Configuration - Works out of the box with free Etherspot bundlers
• 🌐 Multi-Chain Support - Ethereum, Arbitrum, Optimism
• 🔧 Fully Configurable - Override any default settings
• 📦 TypeScript First - Full type safety with viem integration
• 🎯 Tree Shakeable - Import only what you need
• ⚡ Bun Compatible - Optimized for Bun runtime and toolchain

Installation

bun add @etherspot/free-bundler viem
# or
npm install @etherspot/free-bundler viem
# or
yarn add @etherspot/free-bundler viem
# or
pnpm add @etherspot/free-bundler viem

Quick Start

import { createFreeBundler } from '@etherspot/free-bundler'
import { mainnet } from 'viem/chains'

// Create bundler client for Ethereum Sepolia
const bundlerClient = createFreeBundler({ chain: mainnet })

// Send a user operation
const hash = await bundlerClient.sendUserOperation({
  smartAccount,
  userOperation: {
    sender: '0x...',
    nonce: 0n,
    callData: '0x...',
    // ... other fields
  },
  entryPoint: '0x43370900c8de573dB349BEd8DD53b4Ebd3Cce709'
})

Development with Bun

This package is optimized for Bun and includes specific Bun configurations:

# Install dependencies
bun install

# Run development build
bun run dev

# Run tests with Bun's built-in test runner
bun test

# Run tests with coverage
bun test --coverage

# Build the package
bun run build

# Type checking
bun run typecheck

# Linting
bun run lint
bun run lint:fix

Supported Chains

Chain	Chain ID	Network
Ethereum	1	Mainnet
Ethereum Sepolia	11155111	Testnet
Arbitrum Sepolia	421614	Testnet
Optimism	10	Mainnet
Optimism Sepolia	11155420	Testnet

API Reference

createFreeBundler(options)

Creates a bundler client with preconfigured settings.

Parameters

• options (object, optional):
  • bundlerUrl? (string): Custom bundler URL
  • chain (Chain): Viem chain configuration
  • account? (Smart Account): Viem smart account configuration
  • transport? (object): HTTP transport options
    • timeout? (number): Request timeout in ms (default: 30000)
    • retryCount? (number): Number of retries (default: 3)
    • retryDelay? (number): Delay between retries in ms (default: 150)
  • client? (object): Additional client options
    • name? (string): Client name (default: "Free Bundler Client")
    • pollingInterval? (number): Polling interval in ms (default: 4000)

Returns

A viem bundler client with all bundler actions available.

Utility Functions

import {
  getSupportedChainIds,
  isChainSupported,
  getBundlerConfig,
  getChainName
} from '@etherspot/free-bundler'

// Check supported chains
const chainIds = getSupportedChainIds() // [1, 11155111, ...]
const isSupported = isChainSupported(1) // true

// Get chain information
const config = getBundlerConfig(1)
// { chainId: 1, name: 'Ethereum Mainnet', url: '...', isTestnet: false }

const name = getChainName(1) // 'Ethereum Mainnet'

Advanced Usage

Custom Transport Configuration

const bundlerClient = createFreeBundler({
  transport: {
    timeout: 15000,
    retryCount: 5,
    retryDelay: 200
  },
  chain: mainnet
})

Custom Bundler URL

const bundlerClient = createFreeBundler({
  bundlerUrl: 'https://your-custom-bundler.com',
  chain: mainnet
})

With Chain and Account Configuration

import { createFreeBundler } from '@etherspot/free-bundler'
import { mainnet } from 'viem/chains'
import { toSmartAccount } from 'viem/account-abstraction'

const account = toSmartAccount({...});

const bundlerClient = createFreeBundler({
  chain: mainnet,
  account,
  client: {
    name: 'My Custom Bundler',
    pollingInterval: 2000
  }
})

Error Handling

import { createFreeBundler, isChainSupported } from '@etherspot/free-bundler'

try {
  // Check if chain is supported first
  if (!isChainSupported(999)) {
    throw new Error('Chain not supported')
  }
  
  const bundlerClient = createFreeBundler(999)
} catch (error) {
  console.error('Failed to create bundler:', error.message)
}

Bun Specific Features

This package takes advantage of Bun's capabilities:

• Fast Installation: Uses Bun's lightning-fast package manager
• Built-in Testing: Leverages Bun's native test runner
• TypeScript Support: No additional transpilation needed
• ESM First: Optimized for modern JavaScript modules

Runtime Compatibility

• Bun: >=1.0.0 (recommended)
• Node.js: >=18.0.0
• Browser: Modern browsers with ESM support

License

MIT