BitcoinJ Bitcoin Project

Telegram Channel BitcoinJ   Bitcoin Project – 4 Members

What is bitcoinj?

bitcoinwallet  rsk
Some projects using bitcoinj

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.

It comes with full documentation and many large, well known Bitcoin apps and services are built on it.


  • Highly optimised lightweight simplified payment verification (SPV) mode. In this mode, only a small part of the block chain is downloaded, making bitcoinj suitable for usage on constrained devices like smartphones or cheap virtual private servers.
  • 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 and, thanks to a PostgreSQL store, can be indexed into a database allowing for fast lookup of balance by address.
  • 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.
  • Support for micropayment channels that let you set up a multi-signature contract between client and server, and then negotiate on the channel, allowing fast micropayments that avoid miner fees.
  • Provides both async and thread-per-connection for network IO, allowing you to choose between scalability and blocking-only features like SOCKS proxying.
  • Easily implement apps that use Bitcoin’s contracts features.
  • A simple GUI wallet app that you can use as the basis for your own apps. Watch or read a tutorial on how to customise it and build a native installer that does not require Java.
  • Command line tools for working with wallet and chain files, the payment protocol, the network and more.
  • Strong Bitcoin standards support.
  • A friendly and helpful community!


Read the API documentation: 0.15.7 API documentation

There are also some more in depth articles covering various topics. For best understanding, read them in order.


Core APIs in depth

bitcoinj TV

Advanced features

You can read the release notes for each release starting from 0.3.


  • View bitcoinj on Github – make sure to star us!
  • Ask questions and discuss improvements on the mailing list
  • Search and report issues on the Issues Data Base (to ask for help please use the mailing list, not the Issues DB)
  • Join our IRC channel, #bitcoinj on freenode.
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Written by Ramon Quesada

Passionate about Blockchain & Bitcoin technology since 2013, Co- Founder of, Team Manager in the CoinTelegraph Spain franchise (2016-2017 years) Co. Organizer of the Blockchain Boot camp Valencia 2018, Co. Organizer of the mini Hackathon BitcoinSV Barcelona, in August 2019, current coordinator of the BSV Valencia Meetup.

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