Joinmarket refactored to separate client and backend operations
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AdamISZ Merge #216: Replace deprecated py.test syntax with pytest.
089f75c Replace deprecated py.test syntax with pytest. (James Hilliard)
Latest commit 1fd9176 Nov 14, 2018


Joinmarket refactored to separate client and backend operations

The latest release uses segwit wallets by default, you are strongly recommended not to change this, but you can use a non-segwit wallet by setting segwit = false in joinmarket.cfg.


For good quality privacy, performance and reliability, Bitcoin Core is required for Makers (yield generators), and recommended for takers (doing coinjoins). Use version 0.15+ ideally; 0.13.1+ required.

For doing coinjoins (Taker side), you can also run without Bitcoin Core, connecting to Electrum servers.

Once you've downloaded this repo, either as a zip file, and extracted it, or via git clone:

(follow instructions on screen; provide sudo password when prompted)
source jmvenv/bin/activate
cd scripts

You should now be able to run the scripts like python etc., just as you did in the previous Joinmarket version.

Alternative to this "quickstart" (including for MacOS): follow the install guide.

Upgrade for segwit

See the segwit upgrade guide if you need to update your wallet.


If you are new, follow and read the links in the usage guide.

If you are running Joinmarket-Qt, you can instead use the walkthrough to start.

If you are not new to Joinmarket, the notes in the scripts readme help to understand what has and hasn't changed about the scripts.


Provides single join and multi-join/tumbler functionality (i.e. "Taker") only, in a GUI.

Binaries that are built and signed will be in the Releases page.
To run the script from the command line, both the PyQt4 and sip libraries are needed as dependencies. To make these two libraries available to Joinmarket, it's best to create symbolic links (symlinks) for them in the virtualenv directory jmvenv.
For Debian and Ubuntu users, the install script attempts to install python-qt4 and python-sip from the repositories, and then creates appropriate symlinks for them in the jmvenv directory.
The steps to manually set up the Qt dependencies on Ubuntu\Debian are

  1. first activate the Joinmarket virtualenv
    source ./jmvenv/bin/activate
  2. Install the required dependencies
    sudo apt-get install python-qt4 python-sip
  3. Locate the installed files
    dpkg-query -L python-qt4 | grep -m1 "/PyQt4$"
    dpkg-query -L python-sip | grep -m1 "sip.*\.so"
  4. Create symlinks to each of the paths returned by the two previous commands in the virtualenv directory
    ln -sf -t "${VIRTUAL_ENV}/lib/python2.7/site-packages/" <python-qt4 path> <python-sip path>

The last two commands can be combined as :

ln -sf -t "${VIRTUAL_ENV}/lib/python2.7/site-packages/" "$(dpkg-query -L python-qt4 | grep -m1 "/PyQt4$")" "$(dpkg-query -L python-sip | grep -m1 "sip.*\.so")"

Finally, the command python from within the scripts subdirectory should work. There is a walkthrough for what to do next.

Notes on architectural changes (can be ignored)

Motivation: By separating the code which manages conversation with other Joinmarket participants from the code which manages this participant's Bitcoin wallet actions, we get a considerable gain at a minor cost of an additional layer: code dependencies for each part are much reduced, security requirements of the server/daemon layer are massively reduced (which can have several advantages such as it being more acceptable to distribute this layer as a binary), and client code can be written, implementing application-level logic (do join with coins X under condition X) using other Bitcoin libraries, or wallets, without knowing anything about Joinmarket's inter-participant protocol. An example is my work on the Joinmarket electrum plugin.

It also means that updates to the Bitcoin element of Joinmarket, such as P2SH and segwit, should have extremely minimal to no impact on the backend code, since the latter just implements communication of a set of formatted messages, and allows the client to decide on their validity beyond simply syntax.

Joinmarket's own messaging protocol is thus enforced only in the server/daemon.

The client and server currently communicate using twisted.protocol.amp, see AMP, and the specification of the communication between the client and server is isolated to this module. Currently the messaging layer of Joinmarket is IRC-only (but easily extensible, see here. The IRC layer is also implemented here using Twisted, reducing the complexity required with threading.

The "server" is just a daemon service that can be run as a separate process (see scripts/, or for convenience in the same process (the default for command line scripts).


Instructions for developers for testing here. If you want to help improve the project, please have a read of this todo list.