Rhasspy Hermes is an extensive library implementing Hermes protocol support in Rhasspy. It implements a lot of the low-level details such as MQTT communication and converting JSON payloads and binary payloads to more usable Python classes. Thanks to the HermesClient class and the cli module, you can easily implement a Rhasspy ‘app’.

However, the result still needs a lot of lines of code. If you want to have control over the finer details of the Rhasspy Hermes library, this is fine. But if you just want to create a simple voice app that tells you the time, it should be easier. This is where the Rhasspy Hermes App library comes in. Its lets you write code such as the following:

"""Example app to react to an intent to tell you the time."""
import logging
from datetime import datetime

from rhasspyhermes.nlu import NluIntent

from rhasspyhermes_app import EndSession, HermesApp

_LOGGER = logging.getLogger("TimeApp")

app = HermesApp("TimeApp")

async def get_time(intent: NluIntent):
    """Tell the time."""
    now = datetime.now().strftime("%H %M")
    return EndSession(f"It's {now}")


In fact, the code using Rhasspy Hermes directly and the one using Rhasspy Hermes App are doing exactly the same. Thanks to the extra abstraction layer of the Rhasspy Hermes App library, a few lines of code are enough to start a whole machinery behind the scenes.