Bitcoinjs

bitcoinjs-lib is a widely used JavaScript library designed for Bitcoin protocol operations in both Node.js and browser environments. Written in TypeScript with committed JavaScript files for verification, it provides developers with tools to create, sign, and manage Bitcoin transactions and addresses, including support for legacy, SegWit, and Taproot features. The library emphasizes security and auditability, with over 95% test coverage and adherence to Bitcoin standards. It is modular, allowing developers to include only necessary cryptographic components to reduce bundle size.

The library supports advanced Bitcoin scripting capabilities such as multisignature wallets, time-locked transactions (using CHECKLOCKTIMEVERIFY and CHECKSEQUENCEVERIFY), and various address formats (P2PKH, P2SH, P2WPKH, P2WSH). It integrates with complementary libraries for mnemonic generation (BIP39), key derivation (BIP32), and fee optimization (coinselect). bitcoinjs-lib is suitable for developers building wallets, payment processors, or any Bitcoin-related infrastructure requiring low-level transaction control.

What sets bitcoinjs-lib apart is its strong community support, extensive documentation, and rigorous testing. It encourages users to verify cryptographic operations and random number generation due to the critical security implications in Bitcoin key management. The library also provides a browser-friendly build process and alternative ECC libraries to accommodate different environments, including those with WebAssembly limitations. Developers can get started by installing via npm and exploring comprehensive examples and integration tests available in the repository.