First, import the module:

>>> import jack

Then, you most likely want to create a new jack.Client:

>>> client = jack.Client('MyGreatClient')

You probably want to create some audio input and output ports, too:

>>> client.inports.register('input_1')
>>> client.outports.register('output_1')

As you can see, these functions return the newly created port. If you want, you can save it for later:

>>> in2 = client.inports.register('input_2')
>>> out2 = client.outports.register('output_2')

To see what you can do with the returned objects, have a look at the documentation of the class jack.OwnPort.

In case you forgot, you should remind yourself about the ports you just created:

>>> client.inports
[jack.OwnPort('MyGreatClient:input_1'), jack.OwnPort('MyGreatClient:input_2')]
>>> client.outports
[jack.OwnPort('MyGreatClient:output_1'), jack.OwnPort('MyGreatClient:output_2')]

Have a look at the documentation of the class jack.Ports to get more detailed information about these lists of ports.

If you have selected an appropriate driver in your JACK settings, you can also create MIDI ports:

>>> client.midi_inports.register('midi_in')
>>> client.midi_outports.register('midi_out')

You can check what other JACK ports are available (your output may be different):

>>> client.get_ports()  

Note that the ports you created yourself are of type jack.OwnPort and jack.OwnMidiPort, while other ports are merely of type jack.Port and jack.MidiPort, respectively.

You can also be more specific when looking for ports:

>>> client.get_ports(is_audio=True, is_output=True, is_physical=True)
[jack.Port('system:capture_1'), jack.Port('system:capture_2')]

You can even use regular expressions to search for ports:

>>> client.get_ports('Great.*2$')
[jack.OwnPort('MyGreatClient:input_2'), jack.OwnPort('MyGreatClient:output_2')]

If you want, you can also set all kinds of callback functions for your client. For details see the documentation for the class jack.Client and the example applications in the examples/ directory.

Once you are ready to run, you should activate your client:

>>> client.activate()

As soon as the client is activated, you can make connections (this isn’t possible before activating the client):

>>> client.connect('system:capture_1', 'MyGreatClient:input_1')
>>> client.connect('MyGreatClient:output_1', 'system:playback_1')

You can also use the port objects from before instead of port names:

>>> client.connect(out2, 'system:playback_2')
>>> in2.connect('system:capture_2')

Use jack.Client.get_all_connections() to find out which other ports are connected to a given port. If you own the port, you can also use jack.OwnPort.connections.

>>> client.get_all_connections('system:playback_1')
>>> out2.connections

Of course you can also disconnect ports, there are again several possibilities:

>>> client.disconnect('system:capture_1', 'MyGreatClient:input_1')
>>> client.disconnect(out2, 'system:playback_2')
>>> in2.disconnect()  # disconnect all connections with in2

If you don’t need your ports anymore, you can un-register them:

>>> in2.unregister()
>>> client.outports.clear()  # unregister all audio output ports

Finally, you can de-activate your JACK client and close it:

>>> client.deactivate()
>>> client.close()