# ethers.js — Complete Ethereum Library and Wallet for JavaScript

> ethers.js is a compact, complete library for interacting with the Ethereum blockchain from JavaScript and TypeScript. It separates concerns into Providers (read-only chain access) and Signers (transaction signing), making it straightforward to build DApps, scripts, and backend services that communicate with smart contracts.

## Install

Save as a script file and run:

# ethers.js — Complete Ethereum Library and Wallet for JavaScript

## Quick Use
```bash
npm install ethers

# In your script
# const { ethers } = require('ethers');
# const provider = new ethers.JsonRpcProvider('https://mainnet.infura.io/v3/KEY');
# const balance = await provider.getBalance('0x...');
```

## Introduction
ethers.js is a widely used JavaScript library for Ethereum development created by Richard Moore. Its design separates the provider (read-only connection) from the signer (wallet with private key), making code simpler and more secure. ethers.js is known for its small footprint, thorough documentation, and TypeScript-first approach.

## What ethers.js Does
- Connects to Ethereum nodes through JSON-RPC, WebSocket, Infura, Alchemy, and Etherscan providers
- Deploys and interacts with smart contracts via typed Contract objects
- Manages wallets, signs transactions, and supports HD derivation paths
- Encodes and decodes ABI data, function selectors, and event logs
- Resolves ENS names and supports EIP-712 typed data signing

## Architecture Overview
The library is structured around four core concepts: Provider (read-only chain access), Signer (write access with a private key or hardware wallet), Contract (typed interface to deployed contracts), and Utils (encoding, hashing, formatting). In v6, the library is split into sub-packages for tree-shaking. The provider layer abstracts multiple backend transports behind a unified interface, while Contract objects automatically generate callable methods from ABI definitions.

## Self-Hosting & Configuration
- Install with `npm install ethers` for the full bundle or import sub-paths for smaller builds
- Create a provider by passing an RPC URL to `JsonRpcProvider` or use `BrowserProvider` for MetaMask
- Instantiate wallets with `new ethers.Wallet(privateKey, provider)` for signing
- Use `Contract` factory with address + ABI + signer/provider to interact with deployed contracts
- Configure custom networks by passing chain ID and RPC details to the provider constructor

## Key Features
- Small bundle size compared to alternatives, with tree-shakeable sub-packages in v6
- Provider/Signer separation enforces security best practices
- Human-readable ABI format simplifies contract interface definitions
- Built-in ENS support for resolving `.eth` names to addresses
- Extensive TypeScript typings with inferred contract method signatures

## Comparison with Similar Tools
- **web3.js** — Larger API surface with plugin system; ethers.js is leaner with clearer abstractions
- **Viem** — Newer TypeScript library with composable actions; ethers.js has a larger existing user base
- **Wagmi** — React hooks built on Viem; ethers.js is framework-agnostic and lower level
- **Alchemy SDK** — Wraps ethers.js with Alchemy-specific features; ethers.js is provider-neutral

## FAQ
**Q: Should I use ethers.js v5 or v6?**
A: v6 is the current release with improved TypeScript support and smaller bundles. v5 is still widely used but will receive only critical fixes.

**Q: How do I connect to MetaMask in a browser?**
A: Use `new ethers.BrowserProvider(window.ethereum)` to wrap the injected provider and request account access.

**Q: Can ethers.js work with Layer 2 networks?**
A: Yes. Point the provider to any EVM-compatible RPC endpoint (Arbitrum, Optimism, Base, Polygon).

**Q: Is ethers.js suitable for backend use?**
A: Yes. It works in Node.js for indexers, bots, and backend services alongside browser DApps.

## Sources
- https://github.com/ethers-io/ethers.js
- https://docs.ethers.org

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Source: https://tokrepo.com/en/workflows/asset-42775cdc
Author: Script Depot