a base app in AppDaemon

appmodule.py

import appdaemon.plugins.hass.hassapi as hass
import base

class MyApp(hass.Hass):
  def initialize(self):
    self.depends_on_module(base)
    base.App(self)
    
    res = self.something()
    self.log(res)  # logs "thing" from base.py

apps.yaml

global_modules:
  - base
  
myapp:
  module: appmodule
  class: MyApp

base.py

class App(object):

    def __init__(self, app):
        self.app = app
        self.extend()

    def add_to_app(self, fn):
        fn_name = fn.__name__
        setattr(self.app, fn_name, types.MethodType(fn, self.app))
        return None

    def extend(self):
      
        @self.add_to_app
        def something(self):
          return "thing"