The idea behind JoinMarket is to help create a special kind of bitcoin transaction called a CoinJoin transaction. It's aim is to improve the confidentiality and privacy of bitcoin transactions, as well as improve the capacity of the blockchain therefore reduce costs. The concept has enormous potential, but had not seen much usage despite the multiple projects that implement it. This is probably because the incentive structure was not right.

A CoinJoin transaction requires other people to take part. The right resources (coins) have to be in the right place, at the right time, in the right quantity. This isn't a software or tech problem, its an economic problem. JoinMarket works by creating a new kind of market that would allocate these resources in the best way.

One group of participants (called market makers) will always be available to take part in CoinJoins at any time. Other participants (called market takers) can create a CoinJoin at any time. The takers pay a fee which incentivizes the makers. A form of smart contract is created, meaning the private keys will never be broadcasted outside of your computer, resulting in virtually zero risk of loss (aside from malware or bugs). As a result of free-market forces the fees will eventually be next to nothing.

Widespread use of JoinMarket could improve bitcoin's fungibility as a commodity. The privacy aspect has many applications. For example, some users of bitcoin exchanges have a problem of being front-run. As all bitcoin transactions are public, when a seller sends a large amount of coins to an exchange it will be public knowledge and the price will move downwards accordingly.

Go to wiki to get started, or for more in depth technical information, see design doc.

The installation is slightly changed, with the secp256k1 python binding no longer being optional, and libnacl now being installed via pip, not locally. The short version is: do follow the below process, for example the secp256k1 binding must be the latest version else you'll get errors. Of course if you already have libsodium you don't need to re-install it. Be sure to read the release notes.

• You will need python 2.7

• You will need libsodium installed

• Debian/Ubuntu, apt-get install libsodium-dev

• Arch, pacman -S libsodium

• or build:

  git clone git://github.com/jedisct1/libsodium.git
  cd libsodium
  git checkout tags/1.0.3
  ./autogen.sh
  ./configure
  make check
  sudo make install
  

• Install Python dependencies: You need pip >= 1.5.6 (e.g. sudo apt-get install python-pip, recent Python usually ships with pip).

  (Setuptools version must be >= 3.3).

  (Recommended but not needed) : use virtualenv to keep dependencies isolated.

  If on Linux/OSX:

  The Python binding to libsecp256k1 will most likely have some dependencies; read the Wiki article.

  Try running the below without following those instructions, most likely it will fail and you will then have to follow them.

  sudo pip install -r requirements.txt
  

  (if you did setup 'virtualenv' mentioned above, you can omit the 'sudo')

• Matplotlib for displaying the graphs in orderbook-watcher (optional)

1. sudo apt-get update -y && sudo apt-get upgrade -y && sudo apt-get install python-dev libsodium-dev python-pip -y
2. Download JoinMarket 0.2.3 source from the releases page or this direct link to v0.2.3: wget https://github.com/JoinMarket-Org/joinmarket/archive/v0.2.3.tar.gz -O joinmarket-0.2.3.tar.gz
3. Extract with tar xzf joinmarket-0.2.3.tar.gz and then cd joinmarket-0.2.3
4. sudo pip install -r requirements.txt
5. Generating your first wallet (python wallet-tool.py generate) will populate the configuration file: joinmarket.cfg. Check if the default settings suit your needs.

Tested up to TAILS version 2.6, but future versions likely will work as well.

1. Make sure that you choose 'more options' when booting up tails and set an administrator password.
2. sudo apt-get update -y
3. sudo apt-get install build-essential automake libtool pkg-config libffi-dev python-dev python libsodium-dev python-pip -y
4. Download JoinMarket 0.2.3 source from the releases page or this direct link to v0.2.3: wget https://github.com/JoinMarket-Org/joinmarket/archive/v0.2.3.tar.gz -O joinmarket-0.2.3.tar.gz
5. Extract with tar xzf joinmarket-0.2.3.tar.gz and then cd joinmarket-0.2.3
6. sudo torsocks pip install -r requirements.txt
7. sudo chmod -R ugo+rX /usr/local/lib/python2.7/dist-packages/
8. sudo cp -r /usr/local/lib/python2.7/dist-packages/libnacl .
9. sudo chown -R amnesia:amnesia libnacl
10. Generating your first wallet (torify python wallet-tool.py generate) will populate the configuration file: joinmarket.cfg. Check if the default settings suit your needs.
11. Prepend commands with torify, i.e. torify python sendpayment.py ...

Clone the repo, then read the notes here.

Install the development requirements:

pip install -r requirements-dev.txt

Run the tests:

PYTHONPATH=.:$PYTHONPATH py.test

Generating html code coverage reports:

PYTHONPATH=.:$PYTHONPATH py.test --cov-report html --nirc=2 --btcroot=/path/to/bitcoin/bin/ --btcconf=/path/to/bitcoin.conf --btcpwd=123456abcdef
open htmlcov/index.html

See more information on testing in the Wiki page

• IRC: #joinmarket on irc.freenode.net https://webchat.freenode.net/?channels=%23joinmarket

• Bitcointalk thread: https://bitcointalk.org/index.php?topic=919116.msg10096563

• Subreddit: https://reddit.com/r/joinmarket

• Twitter: https://twitter.com/joinmarket

• Donation address: 1AZgQZWYRteh6UyF87hwuvyWj73NvWKpL