You can use Flask config (http://flask.pocoo.org/docs/config/):
```
# Values are automatically loaded from default 
# configuration from each module and later overwritten
# by values from var/invenio.base-instance/invenio.cfg
current_app.config['MATCHER_*']
# you can make a copy and append your custom config
my_config.update(current_app.config)
my_config.update(user_config)
```
see also see https://github.com/inveniosoftware/flask-registry/blob/master/flask_registry/registries/appdiscovery.py#L192