async.py

#project.async
celery = None

def make_celery(app):
    #...set celery up
    global celery
    celery = Celery(app.import_name, broker=app.config['CELERY_BROKER_URL'])
    celery.conf.update(app.config)
    TaskBase = celery.Task
    class ContextTask(TaskBase):
        abstract = True
        def __call__(self, *args, **kwargs):
            with app.app_context():
                return TaskBase.__call__(self, *args, **kwargs)
    celery.Task = ContextTask

#project.__init__
create_app(*kwargs):
    
    app = Flaks(__name__)
    db.init_app(app)
    
    make_celery(app)

#project.tasks
from project.async import celery
    
@celery.task
def add(x, y):
    x + y