Writing a New Backend

A backend is a Python module with one or more of these:

Input -- an input port class
Output -- an output port class
IOPort -- an I/O port class
get_devices() -- returns a list of devices

Once written, the backend can be used by setting the environment variable MIDO_BACKEND or by calling mido.set_backend(). In both cases, the path of the module is used.


And input class for open_input(). This is only required if the backend supports input.


And output class for open_output(). This is only required if the backend supports output.


An I/O port class for open_ioport(). If this is not found, open_ioport() will return mido.ports.IOPort(Input(), Output()).


Returns a list of devices, where each device is dictionary with at least these three values:

  'name': 'Some MIDI Input Port',
  'is_input': True,
  'is_output': False,

These are used to build return values for get_input_names() etc.. This function will also be available to the user directly.

For examples, see mido/backends/.