bitcoinj is a library for working with the Bitcoin protocol. It can maintain a wallet, send/receive transactions without needing a local copy of Bitcoin Core and has many other advanced features. It's implemented in Java but can be used from any JVM compatible language, examples in Python and JavaScript are included. Highly optimized lightweight simplified payment verification (SPV) mode. In this mode, only a small part of the blockchain is downloaded, making bitcoin suitable for usage on constrained devices like smartphones or cheap virtual private servers. A wallet class with encryption, fee calculation, multi-signing, deterministic key derivation, pluggable coin selection/coin control, extensions support and event listeners that let you stay up to date with changes in your balance. Experimental full verification mode, which does the same verification work as Bitcoin Core. In this mode, the unspent transaction output set (UTXO set) is calculated.
Features
- Support for micropayment channels that let you set up a multi-signature contract between client and server
- A wallet class with encryption, fee calculation, multi-signing, deterministic key derivation
- Stay up to date with changes in your balance
- Provides both async and thread-per-connection for network IO
- Easily implement apps that use Bitcoin's contracts features
- Command line tools for working with wallet and chain files, the payment protocol, the network and more
Project Samples
