ethers.js is a production-grade TypeScript library for interacting with Ethereum-compatible blockchains, compiled to dual ESM and CommonJS packages with browser-specific module replacements (crypto, base64, geturl, ws, wordlists). The architecture is a modular facade: a top-level barrel (src.ts/index.ts) re-exports sub-modules for ABI encoding, address handling, contracts, crypto primitives, hashing, providers, transactions, utilities, wallets, and BIP-39 wordlists. The provider layer is the deepest abstraction — an AbstractProvider base class with polling/socket/filter-ID subscriber contracts, plus concrete implementations for JSON-RPC, WebSocket, IPC, browser-injected wallets (EIP-1193/6963), and community services (Infura, Alchemy, Etherscan, Chainstack, Ankr, QuickNode, Blockscout, Pocket, Cloudflare) with hardcoded community API keys and once-per-service throttle messages. Network-specific behavior is customizable through a plugin system (GasCostPlugin, EnsPlugin, FeeDataNetworkPlugin), and a FallbackProvider aggregates backends with quorum logic.